From 30c23f29d2d5e3ce8e24f7dec550b7e15142aaef Mon Sep 17 00:00:00 2001 From: Miguel Bernal Marin Date: Mon, 25 Sep 2017 18:03:49 -0500 Subject: [PATCH 01/70] locking/x86: Use named operands in rwsem.h Since GCC version 3.1 it is possible to specify input and output operands using symbolic names, which can be referenced within the assembler code. Converting to named operands makes it easier to understand and maintain the code in the future. Update operands in asm/rwsem.h accordingly. Signed-off-by: Miguel Bernal Marin Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20170925230349.18834-1-miguel.bernal.marin@linux.intel.com Signed-off-by: Ingo Molnar --- arch/x86/include/asm/rwsem.h | 53 ++++++++++++++++++------------------ 1 file changed, 27 insertions(+), 26 deletions(-) diff --git a/arch/x86/include/asm/rwsem.h b/arch/x86/include/asm/rwsem.h index 7116b7931c7b..a8f486e7a124 100644 --- a/arch/x86/include/asm/rwsem.h +++ b/arch/x86/include/asm/rwsem.h @@ -63,14 +63,14 @@ static inline void __down_read(struct rw_semaphore *sem) { asm volatile("# beginning down_read\n\t" - LOCK_PREFIX _ASM_INC "(%1)\n\t" + LOCK_PREFIX _ASM_INC "(%[sem])\n\t" /* adds 0x00000001 */ " jns 1f\n" " call call_rwsem_down_read_failed\n" "1:\n\t" "# ending down_read\n\t" : "+m" (sem->count) - : "a" (sem) + : [sem] "a" (sem) : "memory", "cc"); } @@ -81,17 +81,18 @@ static inline bool __down_read_trylock(struct rw_semaphore *sem) { long result, tmp; asm volatile("# beginning __down_read_trylock\n\t" - " mov %0,%1\n\t" + " mov %[count],%[result]\n\t" "1:\n\t" - " mov %1,%2\n\t" - " add %3,%2\n\t" + " mov %[result],%[tmp]\n\t" + " add %[inc],%[tmp]\n\t" " jle 2f\n\t" - LOCK_PREFIX " cmpxchg %2,%0\n\t" + LOCK_PREFIX " cmpxchg %[tmp],%[count]\n\t" " jnz 1b\n\t" "2:\n\t" "# ending __down_read_trylock\n\t" - : "+m" (sem->count), "=&a" (result), "=&r" (tmp) - : "i" (RWSEM_ACTIVE_READ_BIAS) + : [count] "+m" (sem->count), [result] "=&a" (result), + [tmp] "=&r" (tmp) + : [inc] "i" (RWSEM_ACTIVE_READ_BIAS) : "memory", "cc"); return result >= 0; } @@ -105,7 +106,7 @@ static inline bool __down_read_trylock(struct rw_semaphore *sem) struct rw_semaphore* ret; \ \ asm volatile("# beginning down_write\n\t" \ - LOCK_PREFIX " xadd %1,(%4)\n\t" \ + LOCK_PREFIX " xadd %[tmp],(%[sem])\n\t" \ /* adds 0xffff0001, returns the old value */ \ " test " __ASM_SEL(%w1,%k1) "," __ASM_SEL(%w1,%k1) "\n\t" \ /* was the active mask 0 before? */\ @@ -113,9 +114,9 @@ static inline bool __down_read_trylock(struct rw_semaphore *sem) " call " slow_path "\n" \ "1:\n" \ "# ending down_write" \ - : "+m" (sem->count), "=d" (tmp), \ + : "+m" (sem->count), [tmp] "=d" (tmp), \ "=a" (ret), ASM_CALL_CONSTRAINT \ - : "a" (sem), "1" (RWSEM_ACTIVE_WRITE_BIAS) \ + : [sem] "a" (sem), "[tmp]" (RWSEM_ACTIVE_WRITE_BIAS) \ : "memory", "cc"); \ ret; \ }) @@ -141,21 +142,21 @@ static inline bool __down_write_trylock(struct rw_semaphore *sem) bool result; long tmp0, tmp1; asm volatile("# beginning __down_write_trylock\n\t" - " mov %0,%1\n\t" + " mov %[count],%[tmp0]\n\t" "1:\n\t" " test " __ASM_SEL(%w1,%k1) "," __ASM_SEL(%w1,%k1) "\n\t" /* was the active mask 0 before? */ " jnz 2f\n\t" - " mov %1,%2\n\t" - " add %4,%2\n\t" - LOCK_PREFIX " cmpxchg %2,%0\n\t" + " mov %[tmp0],%[tmp1]\n\t" + " add %[inc],%[tmp1]\n\t" + LOCK_PREFIX " cmpxchg %[tmp1],%[count]\n\t" " jnz 1b\n\t" "2:\n\t" CC_SET(e) "# ending __down_write_trylock\n\t" - : "+m" (sem->count), "=&a" (tmp0), "=&r" (tmp1), - CC_OUT(e) (result) - : "er" (RWSEM_ACTIVE_WRITE_BIAS) + : [count] "+m" (sem->count), [tmp0] "=&a" (tmp0), + [tmp1] "=&r" (tmp1), CC_OUT(e) (result) + : [inc] "er" (RWSEM_ACTIVE_WRITE_BIAS) : "memory"); return result; } @@ -167,14 +168,14 @@ static inline void __up_read(struct rw_semaphore *sem) { long tmp; asm volatile("# beginning __up_read\n\t" - LOCK_PREFIX " xadd %1,(%2)\n\t" + LOCK_PREFIX " xadd %[tmp],(%[sem])\n\t" /* subtracts 1, returns the old value */ " jns 1f\n\t" " call call_rwsem_wake\n" /* expects old value in %edx */ "1:\n" "# ending __up_read\n" - : "+m" (sem->count), "=d" (tmp) - : "a" (sem), "1" (-RWSEM_ACTIVE_READ_BIAS) + : "+m" (sem->count), [tmp] "=d" (tmp) + : [sem] "a" (sem), "[tmp]" (-RWSEM_ACTIVE_READ_BIAS) : "memory", "cc"); } @@ -185,14 +186,14 @@ static inline void __up_write(struct rw_semaphore *sem) { long tmp; asm volatile("# beginning __up_write\n\t" - LOCK_PREFIX " xadd %1,(%2)\n\t" + LOCK_PREFIX " xadd %[tmp],(%[sem])\n\t" /* subtracts 0xffff0001, returns the old value */ " jns 1f\n\t" " call call_rwsem_wake\n" /* expects old value in %edx */ "1:\n\t" "# ending __up_write\n" - : "+m" (sem->count), "=d" (tmp) - : "a" (sem), "1" (-RWSEM_ACTIVE_WRITE_BIAS) + : "+m" (sem->count), [tmp] "=d" (tmp) + : [sem] "a" (sem), "[tmp]" (-RWSEM_ACTIVE_WRITE_BIAS) : "memory", "cc"); } @@ -202,7 +203,7 @@ static inline void __up_write(struct rw_semaphore *sem) static inline void __downgrade_write(struct rw_semaphore *sem) { asm volatile("# beginning __downgrade_write\n\t" - LOCK_PREFIX _ASM_ADD "%2,(%1)\n\t" + LOCK_PREFIX _ASM_ADD "%[inc],(%[sem])\n\t" /* * transitions 0xZZZZ0001 -> 0xYYYY0001 (i386) * 0xZZZZZZZZ00000001 -> 0xYYYYYYYY00000001 (x86_64) @@ -212,7 +213,7 @@ static inline void __downgrade_write(struct rw_semaphore *sem) "1:\n\t" "# ending __downgrade_write\n" : "+m" (sem->count) - : "a" (sem), "er" (-RWSEM_WAITING_BIAS) + : [sem] "a" (sem), [inc] "er" (-RWSEM_WAITING_BIAS) : "memory", "cc"); } From 564c9cc84e2adf8a6671c1937f0a9fe3da2a4b0e Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Sat, 2 Sep 2017 13:09:45 -0700 Subject: [PATCH 02/70] locking/refcounts, x86/asm: Use unique .text section for refcount exceptions Using .text.unlikely for refcount exceptions isn't safe because gcc may move entire functions into .text.unlikely (e.g. in6_dev_dev()), which would cause any uses of a protected refcount_t function to stay inline with the function, triggering the protection unconditionally: .section .text.unlikely,"ax",@progbits .type in6_dev_get, @function in6_dev_getx: .LFB4673: .loc 2 4128 0 .cfi_startproc ... lock; incl 480(%rbx) js 111f .pushsection .text.unlikely 111: lea 480(%rbx), %rcx 112: .byte 0x0f, 0xff .popsection 113: This creates a unique .text..refcount section and adds an additional test to the exception handler to WARN in the case of having none of OF, SF, nor ZF set so we can see things like this more easily in the future. The double dot for the section name keeps it out of the TEXT_MAIN macro namespace, to avoid collisions and so it can be put at the end with text.unlikely to keep the cold code together. See commit: cb87481ee89db ("kbuild: linker script do not match C names unless LD_DEAD_CODE_DATA_ELIMINATION is configured") ... which matches C names: [a-zA-Z0-9_] but not ".". Reported-by: Mike Galbraith Signed-off-by: Kees Cook Cc: Ard Biesheuvel Cc: Elena Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-arch Fixes: 7a46ec0e2f48 ("locking/refcounts, x86/asm: Implement fast refcount overflow protection") Link: http://lkml.kernel.org/r/1504382986-49301-2-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar --- arch/x86/include/asm/refcount.h | 2 +- arch/x86/mm/extable.c | 7 ++++++- include/asm-generic/vmlinux.lds.h | 1 + 3 files changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/refcount.h b/arch/x86/include/asm/refcount.h index ff871210b9f2..4e44250e7d0d 100644 --- a/arch/x86/include/asm/refcount.h +++ b/arch/x86/include/asm/refcount.h @@ -15,7 +15,7 @@ * back to the regular execution flow in .text. */ #define _REFCOUNT_EXCEPTION \ - ".pushsection .text.unlikely\n" \ + ".pushsection .text..refcount\n" \ "111:\tlea %[counter], %%" _ASM_CX "\n" \ "112:\t" ASM_UD0 "\n" \ ASM_UNREACHABLE \ diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c index c3521e2be396..3321b446b66c 100644 --- a/arch/x86/mm/extable.c +++ b/arch/x86/mm/extable.c @@ -67,12 +67,17 @@ bool ex_handler_refcount(const struct exception_table_entry *fixup, * wrapped around) will be set. Additionally, seeing the refcount * reach 0 will set ZF (Zero Flag: result was zero). In each of * these cases we want a report, since it's a boundary condition. - * + * The SF case is not reported since it indicates post-boundary + * manipulations below zero or above INT_MAX. And if none of the + * flags are set, something has gone very wrong, so report it. */ if (regs->flags & (X86_EFLAGS_OF | X86_EFLAGS_ZF)) { bool zero = regs->flags & X86_EFLAGS_ZF; refcount_error_report(regs, zero ? "hit zero" : "overflow"); + } else if ((regs->flags & X86_EFLAGS_SF) == 0) { + /* Report if none of OF, ZF, nor SF are set. */ + refcount_error_report(regs, "unexpected saturation"); } return true; diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 8acfc1e099e1..e549bff87c5b 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -459,6 +459,7 @@ #define TEXT_TEXT \ ALIGN_FUNCTION(); \ *(.text.hot TEXT_MAIN .text.fixup .text.unlikely) \ + *(.text..refcount) \ *(.ref.text) \ MEM_KEEP(init.text) \ MEM_KEEP(exit.text) \ From 39208aa7ecb7d9c4e86df782b5693270313cbab1 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Sat, 2 Sep 2017 13:09:46 -0700 Subject: [PATCH 03/70] locking/refcounts, x86/asm: Enable CONFIG_ARCH_HAS_REFCOUNT With the section inlining bug fixed for the x86 refcount protection, we can turn the config back on. Signed-off-by: Kees Cook Cc: Ard Biesheuvel Cc: Elena Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-arch Link: http://lkml.kernel.org/r/1504382986-49301-3-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar --- arch/x86/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 971feac13506..90535646b83d 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -55,7 +55,7 @@ config X86 select ARCH_HAS_KCOV if X86_64 select ARCH_HAS_PMEM_API if X86_64 # Causing hangs/crashes, see the commit that added this change for details. - select ARCH_HAS_REFCOUNT if BROKEN + select ARCH_HAS_REFCOUNT select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 select ARCH_HAS_SET_MEMORY select ARCH_HAS_SG_CHAIN From 9043442b43b1fddf202591b84702863286700c1a Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Wed, 6 Sep 2017 19:36:24 +0200 Subject: [PATCH 04/70] locking/paravirt: Use new static key for controlling call of virt_spin_lock() There are cases where a guest tries to switch spinlocks to bare metal behavior (e.g. by setting "xen_nopvspin" boot parameter). Today this has the downside of falling back to unfair test and set scheme for qspinlocks due to virt_spin_lock() detecting the virtualized environment. Add a static key controlling whether virt_spin_lock() should be called or not. When running on bare metal set the new key to false. Signed-off-by: Juergen Gross Signed-off-by: Peter Zijlstra (Intel) Acked-by: Waiman Long Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: akataria@vmware.com Cc: boris.ostrovsky@oracle.com Cc: chrisw@sous-sol.org Cc: hpa@zytor.com Cc: jeremy@goop.org Cc: rusty@rustcorp.com.au Cc: virtualization@lists.linux-foundation.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/20170906173625.18158-2-jgross@suse.com Signed-off-by: Ingo Molnar --- arch/x86/include/asm/qspinlock.h | 11 ++++++++++- arch/x86/kernel/paravirt.c | 14 ++++++++++++-- arch/x86/kernel/smpboot.c | 2 ++ 3 files changed, 24 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/qspinlock.h b/arch/x86/include/asm/qspinlock.h index 48a706f641f2..308dfd0714c7 100644 --- a/arch/x86/include/asm/qspinlock.h +++ b/arch/x86/include/asm/qspinlock.h @@ -1,6 +1,7 @@ #ifndef _ASM_X86_QSPINLOCK_H #define _ASM_X86_QSPINLOCK_H +#include #include #include #include @@ -46,10 +47,14 @@ static inline void queued_spin_unlock(struct qspinlock *lock) #endif #ifdef CONFIG_PARAVIRT +DECLARE_STATIC_KEY_TRUE(virt_spin_lock_key); + +void native_pv_lock_init(void) __init; + #define virt_spin_lock virt_spin_lock static inline bool virt_spin_lock(struct qspinlock *lock) { - if (!static_cpu_has(X86_FEATURE_HYPERVISOR)) + if (!static_branch_likely(&virt_spin_lock_key)) return false; /* @@ -65,6 +70,10 @@ static inline bool virt_spin_lock(struct qspinlock *lock) return true; } +#else +static inline void native_pv_lock_init(void) +{ +} #endif /* CONFIG_PARAVIRT */ #include diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c index 19a3e8f961c7..041096bdef86 100644 --- a/arch/x86/kernel/paravirt.c +++ b/arch/x86/kernel/paravirt.c @@ -115,8 +115,18 @@ unsigned paravirt_patch_jmp(void *insnbuf, const void *target, return 5; } -/* Neat trick to map patch type back to the call within the - * corresponding structure. */ +DEFINE_STATIC_KEY_TRUE(virt_spin_lock_key); + +void __init native_pv_lock_init(void) +{ + if (!static_cpu_has(X86_FEATURE_HYPERVISOR)) + static_branch_disable(&virt_spin_lock_key); +} + +/* + * Neat trick to map patch type back to the call within the + * corresponding structure. + */ static void *get_call_destination(u8 type) { struct paravirt_patch_template tmpl = { diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index ad59edd84de7..361f91674ce5 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -77,6 +77,7 @@ #include #include #include +#include /* Number of siblings per CPU package */ int smp_num_siblings = 1; @@ -1384,6 +1385,7 @@ void __init native_smp_prepare_boot_cpu(void) /* already set me in cpu_online_mask in boot_cpu_init() */ cpumask_set_cpu(me, cpu_callout_mask); cpu_set_state_online(me); + native_pv_lock_init(); } void __init native_smp_cpus_done(unsigned int max_cpus) From e6fd28eb3522b31f79a938e24674f77268a120fd Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Wed, 6 Sep 2017 19:36:25 +0200 Subject: [PATCH 05/70] locking/spinlocks, paravirt, xen: Correct the xen_nopvspin case With the boot parameter "xen_nopvspin" specified a Xen guest should not make use of paravirt spinlocks, but behave as if running on bare metal. This is not true, however, as the qspinlock code will fall back to a test-and-set scheme when it is detecting a hypervisor. In order to avoid this disable the virt_spin_lock_key. Signed-off-by: Juergen Gross Signed-off-by: Peter Zijlstra (Intel) Acked-by: Waiman Long Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: akataria@vmware.com Cc: boris.ostrovsky@oracle.com Cc: chrisw@sous-sol.org Cc: hpa@zytor.com Cc: jeremy@goop.org Cc: rusty@rustcorp.com.au Cc: virtualization@lists.linux-foundation.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/20170906173625.18158-3-jgross@suse.com Signed-off-by: Ingo Molnar --- arch/x86/xen/spinlock.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c index 25a7c4302ce7..e8ab80ad7a6f 100644 --- a/arch/x86/xen/spinlock.c +++ b/arch/x86/xen/spinlock.c @@ -10,6 +10,7 @@ #include #include +#include #include #include @@ -129,6 +130,7 @@ void __init xen_init_spinlocks(void) if (!xen_pvspin) { printk(KERN_DEBUG "xen: PV spinlocks disabled\n"); + static_branch_disable(&virt_spin_lock_key); return; } printk(KERN_DEBUG "xen: PV spinlocks enabled\n"); From 8c74392a8db9f19f7b2d07f3bb7c5accb4cb4702 Mon Sep 17 00:00:00 2001 From: Kirill Tkhai Date: Fri, 29 Sep 2017 19:05:56 +0300 Subject: [PATCH 06/70] locking/arch, alpha: Add __down_read_killable() Similar to __down_write_killable(), and read killable primitive. Signed-off-by: Kirill Tkhai Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: arnd@arndb.de Cc: avagin@virtuozzo.com Cc: davem@davemloft.net Cc: fenghua.yu@intel.com Cc: gorcunov@virtuozzo.com Cc: heiko.carstens@de.ibm.com Cc: hpa@zytor.com Cc: ink@jurassic.park.msu.ru Cc: mattst88@gmail.com Cc: rientjes@google.com Cc: rth@twiddle.net Cc: schwidefsky@de.ibm.com Cc: tony.luck@intel.com Cc: viro@zeniv.linux.org.uk Link: http://lkml.kernel.org/r/150670115677.23930.5711263025537758463.stgit@localhost.localdomain Signed-off-by: Ingo Molnar --- arch/alpha/include/asm/rwsem.h | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/arch/alpha/include/asm/rwsem.h b/arch/alpha/include/asm/rwsem.h index 77873d0ad293..9624cb4cbf2f 100644 --- a/arch/alpha/include/asm/rwsem.h +++ b/arch/alpha/include/asm/rwsem.h @@ -21,7 +21,7 @@ #define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS #define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS) -static inline void __down_read(struct rw_semaphore *sem) +static inline int ___down_read(struct rw_semaphore *sem) { long oldcount; #ifndef CONFIG_SMP @@ -41,10 +41,24 @@ static inline void __down_read(struct rw_semaphore *sem) :"=&r" (oldcount), "=m" (sem->count), "=&r" (temp) :"Ir" (RWSEM_ACTIVE_READ_BIAS), "m" (sem->count) : "memory"); #endif - if (unlikely(oldcount < 0)) + return (oldcount < 0); +} + +static inline void __down_read(struct rw_semaphore *sem) +{ + if (unlikely(___down_read(sem))) rwsem_down_read_failed(sem); } +static inline int __down_read_killable(struct rw_semaphore *sem) +{ + if (unlikely(___down_read(sem))) + if (IS_ERR(rwsem_down_read_failed_killable(sem))) + return -EINTR; + + return 0; +} + /* * trylock for reading -- returns 1 if successful, 0 if contention */ @@ -94,9 +108,10 @@ static inline void __down_write(struct rw_semaphore *sem) static inline int __down_write_killable(struct rw_semaphore *sem) { - if (unlikely(___down_write(sem))) + if (unlikely(___down_write(sem))) { if (IS_ERR(rwsem_down_write_failed_killable(sem))) return -EINTR; + } return 0; } From c0905115a55c8a3011d7b7e6ee5d63653c1e99f1 Mon Sep 17 00:00:00 2001 From: Kirill Tkhai Date: Fri, 29 Sep 2017 19:06:07 +0300 Subject: [PATCH 07/70] locking/arch, ia64: Add __down_read_killable() Similar to __down_write_killable(), and read killable primitive. Signed-off-by: Kirill Tkhai Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: arnd@arndb.de Cc: avagin@virtuozzo.com Cc: davem@davemloft.net Cc: fenghua.yu@intel.com Cc: gorcunov@virtuozzo.com Cc: heiko.carstens@de.ibm.com Cc: hpa@zytor.com Cc: ink@jurassic.park.msu.ru Cc: mattst88@gmail.com Cc: rientjes@google.com Cc: rth@twiddle.net Cc: schwidefsky@de.ibm.com Cc: tony.luck@intel.com Cc: viro@zeniv.linux.org.uk Link: http://lkml.kernel.org/r/150670116749.23930.14976888440968191759.stgit@localhost.localdomain Signed-off-by: Ingo Molnar --- arch/ia64/include/asm/rwsem.h | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) diff --git a/arch/ia64/include/asm/rwsem.h b/arch/ia64/include/asm/rwsem.h index 8fa98dd303b4..49f7db0a1bcd 100644 --- a/arch/ia64/include/asm/rwsem.h +++ b/arch/ia64/include/asm/rwsem.h @@ -37,15 +37,31 @@ /* * lock for reading */ -static inline void -__down_read (struct rw_semaphore *sem) +static inline int +___down_read (struct rw_semaphore *sem) { long result = ia64_fetchadd8_acq((unsigned long *)&sem->count.counter, 1); - if (result < 0) + return (result < 0); +} + +static inline void +__down_read (struct rw_semaphore *sem) +{ + if (___down_read(sem)) rwsem_down_read_failed(sem); } +static inline int +__down_read_killable (struct rw_semaphore *sem) +{ + if (___down_read(sem)) + if (IS_ERR(rwsem_down_read_failed_killable(sem))) + return -EINTR; + + return 0; +} + /* * lock for writing */ @@ -72,9 +88,10 @@ __down_write (struct rw_semaphore *sem) static inline int __down_write_killable (struct rw_semaphore *sem) { - if (___down_write(sem)) + if (___down_write(sem)) { if (IS_ERR(rwsem_down_write_failed_killable(sem))) return -EINTR; + } return 0; } From a61ba2c8a48f150f5e6b6d14328fc7f1aa32969d Mon Sep 17 00:00:00 2001 From: Kirill Tkhai Date: Fri, 29 Sep 2017 19:06:18 +0300 Subject: [PATCH 08/70] locking/arch, s390: Add __down_read_killable() Similar to __down_write_killable(), and read killable primitive. Signed-off-by: Kirill Tkhai Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: arnd@arndb.de Cc: avagin@virtuozzo.com Cc: davem@davemloft.net Cc: fenghua.yu@intel.com Cc: gorcunov@virtuozzo.com Cc: heiko.carstens@de.ibm.com Cc: hpa@zytor.com Cc: ink@jurassic.park.msu.ru Cc: mattst88@gmail.com Cc: rientjes@google.com Cc: rth@twiddle.net Cc: schwidefsky@de.ibm.com Cc: tony.luck@intel.com Cc: viro@zeniv.linux.org.uk Link: http://lkml.kernel.org/r/150670117817.23930.13068785028558453848.stgit@localhost.localdomain Signed-off-by: Ingo Molnar --- arch/s390/include/asm/rwsem.h | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/arch/s390/include/asm/rwsem.h b/arch/s390/include/asm/rwsem.h index 597e7e96b59e..fda9481dec5c 100644 --- a/arch/s390/include/asm/rwsem.h +++ b/arch/s390/include/asm/rwsem.h @@ -49,7 +49,7 @@ /* * lock for reading */ -static inline void __down_read(struct rw_semaphore *sem) +static inline int ___down_read(struct rw_semaphore *sem) { signed long old, new; @@ -62,10 +62,25 @@ static inline void __down_read(struct rw_semaphore *sem) : "=&d" (old), "=&d" (new), "=Q" (sem->count) : "Q" (sem->count), "i" (RWSEM_ACTIVE_READ_BIAS) : "cc", "memory"); - if (old < 0) + return (old < 0); +} + +static inline void __down_read(struct rw_semaphore *sem) +{ + if (___down_read(sem)) rwsem_down_read_failed(sem); } +static inline int __down_read_killable(struct rw_semaphore *sem) +{ + if (___down_read(sem)) { + if (IS_ERR(rwsem_down_read_failed_killable(sem))) + return -EINTR; + } + + return 0; +} + /* * trylock for reading -- returns 1 if successful, 0 if contention */ From 19c60923010b3f56f10ca1fb6d537c9cc852b3f1 Mon Sep 17 00:00:00 2001 From: Kirill Tkhai Date: Fri, 29 Sep 2017 19:06:28 +0300 Subject: [PATCH 09/70] locking/arch, x86: Add __down_read_killable() Similar to __down_write_killable(), add read killable primitive: extract current __down_read() code to macros and teach it to get different functions as slow_path argument: store ax register to ret, and add sp register and preserve its value. Add call_rwsem_down_read_failed_killable() assembly entry similar to call_rwsem_down_read_failed(): push dx register to stack in additional to common registers, as it's not declarated as modifiable in ____down_read(). Signed-off-by: Kirill Tkhai Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: arnd@arndb.de Cc: avagin@virtuozzo.com Cc: davem@davemloft.net Cc: fenghua.yu@intel.com Cc: gorcunov@virtuozzo.com Cc: heiko.carstens@de.ibm.com Cc: hpa@zytor.com Cc: ink@jurassic.park.msu.ru Cc: mattst88@gmail.com Cc: rientjes@google.com Cc: rth@twiddle.net Cc: schwidefsky@de.ibm.com Cc: tony.luck@intel.com Cc: viro@zeniv.linux.org.uk Link: http://lkml.kernel.org/r/150670118802.23930.1316107715255410256.stgit@localhost.localdomain Signed-off-by: Ingo Molnar --- arch/x86/include/asm/rwsem.h | 35 +++++++++++++++++++++++++---------- arch/x86/lib/rwsem.S | 12 ++++++++++++ 2 files changed, 37 insertions(+), 10 deletions(-) diff --git a/arch/x86/include/asm/rwsem.h b/arch/x86/include/asm/rwsem.h index a8f486e7a124..1e51195c0b63 100644 --- a/arch/x86/include/asm/rwsem.h +++ b/arch/x86/include/asm/rwsem.h @@ -60,18 +60,33 @@ /* * lock for reading */ +#define ____down_read(sem, slow_path) \ +({ \ + struct rw_semaphore* ret; \ + asm volatile("# beginning down_read\n\t" \ + LOCK_PREFIX _ASM_INC "(%[sem])\n\t" \ + /* adds 0x00000001 */ \ + " jns 1f\n" \ + " call " slow_path "\n" \ + "1:\n\t" \ + "# ending down_read\n\t" \ + : "+m" (sem->count), "=a" (ret), \ + ASM_CALL_CONSTRAINT \ + : [sem] "a" (sem) \ + : "memory", "cc"); \ + ret; \ +}) + static inline void __down_read(struct rw_semaphore *sem) { - asm volatile("# beginning down_read\n\t" - LOCK_PREFIX _ASM_INC "(%[sem])\n\t" - /* adds 0x00000001 */ - " jns 1f\n" - " call call_rwsem_down_read_failed\n" - "1:\n\t" - "# ending down_read\n\t" - : "+m" (sem->count) - : [sem] "a" (sem) - : "memory", "cc"); + ____down_read(sem, "call_rwsem_down_read_failed"); +} + +static inline int __down_read_killable(struct rw_semaphore *sem) +{ + if (IS_ERR(____down_read(sem, "call_rwsem_down_read_failed_killable"))) + return -EINTR; + return 0; } /* diff --git a/arch/x86/lib/rwsem.S b/arch/x86/lib/rwsem.S index bf2c6074efd2..dc2ab6ea6768 100644 --- a/arch/x86/lib/rwsem.S +++ b/arch/x86/lib/rwsem.S @@ -98,6 +98,18 @@ ENTRY(call_rwsem_down_read_failed) ret ENDPROC(call_rwsem_down_read_failed) +ENTRY(call_rwsem_down_read_failed_killable) + FRAME_BEGIN + save_common_regs + __ASM_SIZE(push,) %__ASM_REG(dx) + movq %rax,%rdi + call rwsem_down_read_failed_killable + __ASM_SIZE(pop,) %__ASM_REG(dx) + restore_common_regs + FRAME_END + ret +ENDPROC(call_rwsem_down_read_failed_killable) + ENTRY(call_rwsem_down_write_failed) FRAME_BEGIN save_common_regs From 76f8507f7a6442215df19de74f07eabca2462f1e Mon Sep 17 00:00:00 2001 From: Kirill Tkhai Date: Fri, 29 Sep 2017 19:06:38 +0300 Subject: [PATCH 10/70] locking/rwsem: Add down_read_killable() Similar to down_read() and down_write_killable(), add killable version of down_read(), based on __down_read_killable() function, added in previous patches. Signed-off-by: Kirill Tkhai Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: arnd@arndb.de Cc: avagin@virtuozzo.com Cc: davem@davemloft.net Cc: fenghua.yu@intel.com Cc: gorcunov@virtuozzo.com Cc: heiko.carstens@de.ibm.com Cc: hpa@zytor.com Cc: ink@jurassic.park.msu.ru Cc: mattst88@gmail.com Cc: rientjes@google.com Cc: rth@twiddle.net Cc: schwidefsky@de.ibm.com Cc: tony.luck@intel.com Cc: viro@zeniv.linux.org.uk Link: http://lkml.kernel.org/r/150670119884.23930.2585570605960763239.stgit@localhost.localdomain Signed-off-by: Ingo Molnar --- include/asm-generic/rwsem.h | 10 ++++++++++ include/linux/rwsem.h | 1 + kernel/locking/rwsem.c | 16 ++++++++++++++++ 3 files changed, 27 insertions(+) diff --git a/include/asm-generic/rwsem.h b/include/asm-generic/rwsem.h index 6c6a2141f271..b2d68d2d198e 100644 --- a/include/asm-generic/rwsem.h +++ b/include/asm-generic/rwsem.h @@ -37,6 +37,16 @@ static inline void __down_read(struct rw_semaphore *sem) rwsem_down_read_failed(sem); } +static inline int __down_read_killable(struct rw_semaphore *sem) +{ + if (unlikely(atomic_long_inc_return_acquire(&sem->count) <= 0)) { + if (IS_ERR(rwsem_down_read_failed_killable(sem))) + return -EINTR; + } + + return 0; +} + static inline int __down_read_trylock(struct rw_semaphore *sem) { long tmp; diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index 0ad7318ff299..6ac8ee5f15dd 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -111,6 +111,7 @@ static inline int rwsem_is_contended(struct rw_semaphore *sem) * lock for reading */ extern void down_read(struct rw_semaphore *sem); +extern int __must_check down_read_killable(struct rw_semaphore *sem); /* * trylock for reading -- returns 1 if successful, 0 if contention diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index 4d48b1c4870d..e53f7746d9fd 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -28,6 +28,22 @@ void __sched down_read(struct rw_semaphore *sem) EXPORT_SYMBOL(down_read); +int __sched down_read_killable(struct rw_semaphore *sem) +{ + might_sleep(); + rwsem_acquire_read(&sem->dep_map, 0, 0, _RET_IP_); + + if (LOCK_CONTENDED_RETURN(sem, __down_read_trylock, __down_read_killable)) { + rwsem_release(&sem->dep_map, 1, _RET_IP_); + return -EINTR; + } + + rwsem_set_reader_owned(sem); + return 0; +} + +EXPORT_SYMBOL(down_read_killable); + /* * trylock for reading -- returns 1 if successful, 0 if contention */ From 0dc208b5d5feedc795cbf124539decd182c8e99e Mon Sep 17 00:00:00 2001 From: Kirill Tkhai Date: Fri, 29 Sep 2017 19:06:48 +0300 Subject: [PATCH 11/70] locking/rwsem, fs: Use killable down_read() in iterate_dir() There was mutex_lock_interruptible() initially, and it was changed to rwsem, but there were not killable rwsem primitives that time. >From commit 9902af79c01a: "The main issue is the lack of down_write_killable(), so the places like readdir.c switched to plain inode_lock(); once killable variants of rwsem primitives appear, that'll be dealt with" Use down_read_killable() same as down_write_killable() in !shared case, as concurrent inode_lock() may take much time, that may be wanted to be interrupted by user. Signed-off-by: Kirill Tkhai Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: arnd@arndb.de Cc: avagin@virtuozzo.com Cc: davem@davemloft.net Cc: fenghua.yu@intel.com Cc: gorcunov@virtuozzo.com Cc: heiko.carstens@de.ibm.com Cc: hpa@zytor.com Cc: ink@jurassic.park.msu.ru Cc: mattst88@gmail.com Cc: rientjes@google.com Cc: rth@twiddle.net Cc: schwidefsky@de.ibm.com Cc: tony.luck@intel.com Cc: viro@zeniv.linux.org.uk Link: http://lkml.kernel.org/r/150670120820.23930.5455667921545937220.stgit@localhost.localdomain Signed-off-by: Ingo Molnar --- fs/readdir.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/fs/readdir.c b/fs/readdir.c index 89659549c09d..7c584bbb4ce3 100644 --- a/fs/readdir.c +++ b/fs/readdir.c @@ -36,13 +36,12 @@ int iterate_dir(struct file *file, struct dir_context *ctx) if (res) goto out; - if (shared) { - inode_lock_shared(inode); - } else { + if (shared) + res = down_read_killable(&inode->i_rwsem); + else res = down_write_killable(&inode->i_rwsem); - if (res) - goto out; - } + if (res) + goto out; res = -ENOENT; if (!IS_DEADDIR(inode)) { From 26c4eb192c6224e5297496cead36404b62fb071b Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Tue, 3 Oct 2017 19:25:26 +0100 Subject: [PATCH 12/70] locking/rwsem, security/apparmor: Replace homebrew use of write_can_lock() with lockdep The lockdep subsystem provides a robust way to assert that a lock is held, so use that instead of write_can_lock, which can give incorrect results for qrwlocks. Signed-off-by: Will Deacon Signed-off-by: Peter Zijlstra (Intel) Acked-by: John Johansen Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1507055129-12300-1-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar --- security/apparmor/include/lib.h | 11 ----------- security/apparmor/label.c | 8 ++++---- 2 files changed, 4 insertions(+), 15 deletions(-) diff --git a/security/apparmor/include/lib.h b/security/apparmor/include/lib.h index 436b3a722357..f546707a2bbb 100644 --- a/security/apparmor/include/lib.h +++ b/security/apparmor/include/lib.h @@ -19,17 +19,6 @@ #include "match.h" -/* Provide our own test for whether a write lock is held for asserts - * this is because on none SMP systems write_can_lock will always - * resolve to true, which is what you want for code making decisions - * based on it, but wrong for asserts checking that the lock is held - */ -#ifdef CONFIG_SMP -#define write_is_locked(X) !write_can_lock(X) -#else -#define write_is_locked(X) (1) -#endif /* CONFIG_SMP */ - /* * DEBUG remains global (no per profile flag) since it is mostly used in sysctl * which is not related to profile accesses. diff --git a/security/apparmor/label.c b/security/apparmor/label.c index c5b99b954580..ad28e03a6f30 100644 --- a/security/apparmor/label.c +++ b/security/apparmor/label.c @@ -80,7 +80,7 @@ void __aa_proxy_redirect(struct aa_label *orig, struct aa_label *new) AA_BUG(!orig); AA_BUG(!new); - AA_BUG(!write_is_locked(&labels_set(orig)->lock)); + lockdep_assert_held_exclusive(&labels_set(orig)->lock); tmp = rcu_dereference_protected(orig->proxy->label, &labels_ns(orig)->lock); @@ -571,7 +571,7 @@ static bool __label_remove(struct aa_label *label, struct aa_label *new) AA_BUG(!ls); AA_BUG(!label); - AA_BUG(!write_is_locked(&ls->lock)); + lockdep_assert_held_exclusive(&ls->lock); if (new) __aa_proxy_redirect(label, new); @@ -608,7 +608,7 @@ static bool __label_replace(struct aa_label *old, struct aa_label *new) AA_BUG(!ls); AA_BUG(!old); AA_BUG(!new); - AA_BUG(!write_is_locked(&ls->lock)); + lockdep_assert_held_exclusive(&ls->lock); AA_BUG(new->flags & FLAG_IN_TREE); if (!label_is_stale(old)) @@ -645,7 +645,7 @@ static struct aa_label *__label_insert(struct aa_labelset *ls, AA_BUG(!ls); AA_BUG(!label); AA_BUG(labels_set(label) != ls); - AA_BUG(!write_is_locked(&ls->lock)); + lockdep_assert_held_exclusive(&ls->lock); AA_BUG(label->flags & FLAG_IN_TREE); /* Figure out where to put new node */ From a8a217c22116eff6c120d753c9934089fb229af0 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Tue, 3 Oct 2017 19:25:27 +0100 Subject: [PATCH 13/70] locking/core: Remove {read,spin,write}_can_lock() Outside of the locking code itself, {read,spin,write}_can_lock() have no users in tree. Apparmor (the last remaining user of write_can_lock()) got moved over to lockdep by the previous patch. This patch removes the use of {read,spin,write}_can_lock() from the BUILD_LOCK_OPS macro, deferring to the trylock operation for testing the lock status, and subsequently removes the unused macros altogether. They aren't guaranteed to work in a concurrent environment and can give incorrect results in the case of qrwlock. Signed-off-by: Will Deacon Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1507055129-12300-2-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar --- arch/alpha/include/asm/spinlock.h | 10 -------- arch/arc/include/asm/spinlock.h | 3 --- arch/arm/include/asm/spinlock.h | 6 ----- arch/blackfin/include/asm/spinlock.h | 10 -------- arch/hexagon/include/asm/spinlock.h | 10 -------- arch/ia64/include/asm/spinlock.h | 3 --- arch/m32r/include/asm/spinlock.h | 12 ---------- arch/metag/include/asm/spinlock_lnkget.h | 30 ------------------------ arch/metag/include/asm/spinlock_lock1.h | 20 ---------------- arch/mn10300/include/asm/spinlock.h | 12 ---------- arch/parisc/include/asm/spinlock.h | 18 -------------- arch/powerpc/include/asm/spinlock.h | 3 --- arch/s390/include/asm/spinlock.h | 12 ---------- arch/sh/include/asm/spinlock-cas.h | 12 ---------- arch/sh/include/asm/spinlock-llsc.h | 12 ---------- arch/sparc/include/asm/spinlock_32.h | 3 --- arch/tile/include/asm/spinlock_32.h | 16 ------------- arch/tile/include/asm/spinlock_64.h | 18 -------------- arch/xtensa/include/asm/spinlock.h | 2 -- include/asm-generic/qrwlock.h | 20 ---------------- include/linux/rwlock.h | 3 --- include/linux/spinlock.h | 11 --------- include/linux/spinlock_up.h | 3 --- kernel/locking/spinlock.c | 6 ++--- 24 files changed, 2 insertions(+), 253 deletions(-) diff --git a/arch/alpha/include/asm/spinlock.h b/arch/alpha/include/asm/spinlock.h index 718ac0b64adf..7bff6316b8bb 100644 --- a/arch/alpha/include/asm/spinlock.h +++ b/arch/alpha/include/asm/spinlock.h @@ -54,16 +54,6 @@ static inline int arch_spin_trylock(arch_spinlock_t *lock) /***********************************************************/ -static inline int arch_read_can_lock(arch_rwlock_t *lock) -{ - return (lock->lock & 1) == 0; -} - -static inline int arch_write_can_lock(arch_rwlock_t *lock) -{ - return lock->lock == 0; -} - static inline void arch_read_lock(arch_rwlock_t *lock) { long regx; diff --git a/arch/arc/include/asm/spinlock.h b/arch/arc/include/asm/spinlock.h index 47efc8451b70..ce9bfcf1d870 100644 --- a/arch/arc/include/asm/spinlock.h +++ b/arch/arc/include/asm/spinlock.h @@ -410,9 +410,6 @@ static inline void arch_write_unlock(arch_rwlock_t *rw) #endif -#define arch_read_can_lock(x) ((x)->counter > 0) -#define arch_write_can_lock(x) ((x)->counter == __ARCH_RW_LOCK_UNLOCKED__) - #define arch_read_lock_flags(lock, flags) arch_read_lock(lock) #define arch_write_lock_flags(lock, flags) arch_write_lock(lock) diff --git a/arch/arm/include/asm/spinlock.h b/arch/arm/include/asm/spinlock.h index c030143c18c6..f5223260c73e 100644 --- a/arch/arm/include/asm/spinlock.h +++ b/arch/arm/include/asm/spinlock.h @@ -193,9 +193,6 @@ static inline void arch_write_unlock(arch_rwlock_t *rw) dsb_sev(); } -/* write_can_lock - would write_trylock() succeed? */ -#define arch_write_can_lock(x) (ACCESS_ONCE((x)->lock) == 0) - /* * Read locks are a bit more hairy: * - Exclusively load the lock value. @@ -273,9 +270,6 @@ static inline int arch_read_trylock(arch_rwlock_t *rw) } } -/* read_can_lock - would read_trylock() succeed? */ -#define arch_read_can_lock(x) (ACCESS_ONCE((x)->lock) < 0x80000000) - #define arch_read_lock_flags(lock, flags) arch_read_lock(lock) #define arch_write_lock_flags(lock, flags) arch_write_lock(lock) diff --git a/arch/blackfin/include/asm/spinlock.h b/arch/blackfin/include/asm/spinlock.h index f6431439d15d..607ef98c0f6c 100644 --- a/arch/blackfin/include/asm/spinlock.h +++ b/arch/blackfin/include/asm/spinlock.h @@ -48,16 +48,6 @@ static inline void arch_spin_unlock(arch_spinlock_t *lock) __raw_spin_unlock_asm(&lock->lock); } -static inline int arch_read_can_lock(arch_rwlock_t *rw) -{ - return __raw_uncached_fetch_asm(&rw->lock) > 0; -} - -static inline int arch_write_can_lock(arch_rwlock_t *rw) -{ - return __raw_uncached_fetch_asm(&rw->lock) == RW_LOCK_BIAS; -} - static inline void arch_read_lock(arch_rwlock_t *rw) { __raw_read_lock_asm(&rw->lock); diff --git a/arch/hexagon/include/asm/spinlock.h b/arch/hexagon/include/asm/spinlock.h index 53a8d5885887..9f9414b9c303 100644 --- a/arch/hexagon/include/asm/spinlock.h +++ b/arch/hexagon/include/asm/spinlock.h @@ -86,16 +86,6 @@ static inline int arch_read_trylock(arch_rwlock_t *lock) return temp; } -static inline int arch_read_can_lock(arch_rwlock_t *rwlock) -{ - return rwlock->lock == 0; -} - -static inline int arch_write_can_lock(arch_rwlock_t *rwlock) -{ - return rwlock->lock == 0; -} - /* Stuffs a -1 in the lock value? */ static inline void arch_write_lock(arch_rwlock_t *lock) { diff --git a/arch/ia64/include/asm/spinlock.h b/arch/ia64/include/asm/spinlock.h index df2c121164b8..c728dda59bd2 100644 --- a/arch/ia64/include/asm/spinlock.h +++ b/arch/ia64/include/asm/spinlock.h @@ -127,9 +127,6 @@ static __always_inline void arch_spin_lock_flags(arch_spinlock_t *lock, arch_spin_lock(lock); } -#define arch_read_can_lock(rw) (*(volatile int *)(rw) >= 0) -#define arch_write_can_lock(rw) (*(volatile int *)(rw) == 0) - #ifdef ASM_SUPPORTED static __always_inline void diff --git a/arch/m32r/include/asm/spinlock.h b/arch/m32r/include/asm/spinlock.h index a56825592b90..002601371b2f 100644 --- a/arch/m32r/include/asm/spinlock.h +++ b/arch/m32r/include/asm/spinlock.h @@ -137,18 +137,6 @@ static inline void arch_spin_unlock(arch_spinlock_t *lock) * semaphore.h for details. -ben */ -/** - * read_can_lock - would read_trylock() succeed? - * @lock: the rwlock in question. - */ -#define arch_read_can_lock(x) ((int)(x)->lock > 0) - -/** - * write_can_lock - would write_trylock() succeed? - * @lock: the rwlock in question. - */ -#define arch_write_can_lock(x) ((x)->lock == RW_LOCK_BIAS) - static inline void arch_read_lock(arch_rwlock_t *rw) { unsigned long tmp0, tmp1; diff --git a/arch/metag/include/asm/spinlock_lnkget.h b/arch/metag/include/asm/spinlock_lnkget.h index ad8436feed8d..6a932a952d53 100644 --- a/arch/metag/include/asm/spinlock_lnkget.h +++ b/arch/metag/include/asm/spinlock_lnkget.h @@ -136,21 +136,6 @@ static inline void arch_write_unlock(arch_rwlock_t *rw) : "memory"); } -/* write_can_lock - would write_trylock() succeed? */ -static inline int arch_write_can_lock(arch_rwlock_t *rw) -{ - int ret; - - asm volatile ("LNKGETD %0, [%1]\n" - "CMP %0, #0\n" - "MOV %0, #1\n" - "XORNZ %0, %0, %0\n" - : "=&d" (ret) - : "da" (&rw->lock) - : "cc"); - return ret; -} - /* * Read locks are a bit more hairy: * - Exclusively load the lock value. @@ -224,21 +209,6 @@ static inline int arch_read_trylock(arch_rwlock_t *rw) return tmp; } -/* read_can_lock - would read_trylock() succeed? */ -static inline int arch_read_can_lock(arch_rwlock_t *rw) -{ - int tmp; - - asm volatile ("LNKGETD %0, [%1]\n" - "CMP %0, %2\n" - "MOV %0, #1\n" - "XORZ %0, %0, %0\n" - : "=&d" (tmp) - : "da" (&rw->lock), "bd" (0x80000000) - : "cc"); - return tmp; -} - #define arch_read_lock_flags(lock, flags) arch_read_lock(lock) #define arch_write_lock_flags(lock, flags) arch_write_lock(lock) diff --git a/arch/metag/include/asm/spinlock_lock1.h b/arch/metag/include/asm/spinlock_lock1.h index c630444cffe9..8ae12bfc8ad8 100644 --- a/arch/metag/include/asm/spinlock_lock1.h +++ b/arch/metag/include/asm/spinlock_lock1.h @@ -104,16 +104,6 @@ static inline void arch_write_unlock(arch_rwlock_t *rw) rw->lock = 0; } -/* write_can_lock - would write_trylock() succeed? */ -static inline int arch_write_can_lock(arch_rwlock_t *rw) -{ - unsigned int ret; - - barrier(); - ret = rw->lock; - return (ret == 0); -} - /* * Read locks are a bit more hairy: * - Exclusively load the lock value. @@ -171,14 +161,4 @@ static inline int arch_read_trylock(arch_rwlock_t *rw) return (ret < 0x80000000); } -/* read_can_lock - would read_trylock() succeed? */ -static inline int arch_read_can_lock(arch_rwlock_t *rw) -{ - unsigned int ret; - - barrier(); - ret = rw->lock; - return (ret < 0x80000000); -} - #endif /* __ASM_SPINLOCK_LOCK1_H */ diff --git a/arch/mn10300/include/asm/spinlock.h b/arch/mn10300/include/asm/spinlock.h index fe413b41df6c..54f75dac8094 100644 --- a/arch/mn10300/include/asm/spinlock.h +++ b/arch/mn10300/include/asm/spinlock.h @@ -98,18 +98,6 @@ static inline void arch_spin_lock_flags(arch_spinlock_t *lock, * read-locks. */ -/** - * read_can_lock - would read_trylock() succeed? - * @lock: the rwlock in question. - */ -#define arch_read_can_lock(x) ((int)(x)->lock > 0) - -/** - * write_can_lock - would write_trylock() succeed? - * @lock: the rwlock in question. - */ -#define arch_write_can_lock(x) ((x)->lock == RW_LOCK_BIAS) - /* * On mn10300, we implement read-write locks as a 32-bit counter * with the high bit (sign) being the "contended" bit. diff --git a/arch/parisc/include/asm/spinlock.h b/arch/parisc/include/asm/spinlock.h index 55bfe4affca3..136e1c9bb8a9 100644 --- a/arch/parisc/include/asm/spinlock.h +++ b/arch/parisc/include/asm/spinlock.h @@ -168,24 +168,6 @@ static __inline__ int arch_write_trylock(arch_rwlock_t *rw) return result; } -/* - * read_can_lock - would read_trylock() succeed? - * @lock: the rwlock in question. - */ -static __inline__ int arch_read_can_lock(arch_rwlock_t *rw) -{ - return rw->counter >= 0; -} - -/* - * write_can_lock - would write_trylock() succeed? - * @lock: the rwlock in question. - */ -static __inline__ int arch_write_can_lock(arch_rwlock_t *rw) -{ - return !rw->counter; -} - #define arch_read_lock_flags(lock, flags) arch_read_lock(lock) #define arch_write_lock_flags(lock, flags) arch_write_lock(lock) diff --git a/arch/powerpc/include/asm/spinlock.h b/arch/powerpc/include/asm/spinlock.h index edbe571bcc54..d83f4f755ad8 100644 --- a/arch/powerpc/include/asm/spinlock.h +++ b/arch/powerpc/include/asm/spinlock.h @@ -181,9 +181,6 @@ static inline void arch_spin_unlock(arch_spinlock_t *lock) * read-locks. */ -#define arch_read_can_lock(rw) ((rw)->lock >= 0) -#define arch_write_can_lock(rw) (!(rw)->lock) - #ifdef CONFIG_PPC64 #define __DO_SIGN_EXTEND "extsw %0,%0\n" #define WRLOCK_TOKEN LOCK_TOKEN /* it's negative */ diff --git a/arch/s390/include/asm/spinlock.h b/arch/s390/include/asm/spinlock.h index 8182b521c42f..dc9c58ed9e4c 100644 --- a/arch/s390/include/asm/spinlock.h +++ b/arch/s390/include/asm/spinlock.h @@ -110,18 +110,6 @@ static inline void arch_spin_unlock(arch_spinlock_t *lp) * read-locks. */ -/** - * read_can_lock - would read_trylock() succeed? - * @lock: the rwlock in question. - */ -#define arch_read_can_lock(x) ((int)(x)->lock >= 0) - -/** - * write_can_lock - would write_trylock() succeed? - * @lock: the rwlock in question. - */ -#define arch_write_can_lock(x) ((x)->lock == 0) - extern int _raw_read_trylock_retry(arch_rwlock_t *lp); extern int _raw_write_trylock_retry(arch_rwlock_t *lp); diff --git a/arch/sh/include/asm/spinlock-cas.h b/arch/sh/include/asm/spinlock-cas.h index 5ed7dbbd94ff..315467834521 100644 --- a/arch/sh/include/asm/spinlock-cas.h +++ b/arch/sh/include/asm/spinlock-cas.h @@ -53,18 +53,6 @@ static inline int arch_spin_trylock(arch_spinlock_t *lock) * read-locks. */ -/** - * read_can_lock - would read_trylock() succeed? - * @lock: the rwlock in question. - */ -#define arch_read_can_lock(x) ((x)->lock > 0) - -/** - * write_can_lock - would write_trylock() succeed? - * @lock: the rwlock in question. - */ -#define arch_write_can_lock(x) ((x)->lock == RW_LOCK_BIAS) - static inline void arch_read_lock(arch_rwlock_t *rw) { unsigned old; diff --git a/arch/sh/include/asm/spinlock-llsc.h b/arch/sh/include/asm/spinlock-llsc.h index f77263aae760..06be4a55f3c4 100644 --- a/arch/sh/include/asm/spinlock-llsc.h +++ b/arch/sh/include/asm/spinlock-llsc.h @@ -89,18 +89,6 @@ static inline int arch_spin_trylock(arch_spinlock_t *lock) * read-locks. */ -/** - * read_can_lock - would read_trylock() succeed? - * @lock: the rwlock in question. - */ -#define arch_read_can_lock(x) ((x)->lock > 0) - -/** - * write_can_lock - would write_trylock() succeed? - * @lock: the rwlock in question. - */ -#define arch_write_can_lock(x) ((x)->lock == RW_LOCK_BIAS) - static inline void arch_read_lock(arch_rwlock_t *rw) { unsigned long tmp; diff --git a/arch/sparc/include/asm/spinlock_32.h b/arch/sparc/include/asm/spinlock_32.h index 67345b2dc408..76986b8f7dad 100644 --- a/arch/sparc/include/asm/spinlock_32.h +++ b/arch/sparc/include/asm/spinlock_32.h @@ -190,9 +190,6 @@ static inline int __arch_read_trylock(arch_rwlock_t *rw) #define arch_read_relax(lock) cpu_relax() #define arch_write_relax(lock) cpu_relax() -#define arch_read_can_lock(rw) (!((rw)->lock & 0xff)) -#define arch_write_can_lock(rw) (!(rw)->lock) - #endif /* !(__ASSEMBLY__) */ #endif /* __SPARC_SPINLOCK_H */ diff --git a/arch/tile/include/asm/spinlock_32.h b/arch/tile/include/asm/spinlock_32.h index cba8ba9b8da6..91d05f21cba9 100644 --- a/arch/tile/include/asm/spinlock_32.h +++ b/arch/tile/include/asm/spinlock_32.h @@ -79,22 +79,6 @@ static inline void arch_spin_unlock(arch_spinlock_t *lock) #define _RD_COUNT_SHIFT 24 #define _RD_COUNT_WIDTH 8 -/** - * arch_read_can_lock() - would read_trylock() succeed? - */ -static inline int arch_read_can_lock(arch_rwlock_t *rwlock) -{ - return (rwlock->lock << _RD_COUNT_WIDTH) == 0; -} - -/** - * arch_write_can_lock() - would write_trylock() succeed? - */ -static inline int arch_write_can_lock(arch_rwlock_t *rwlock) -{ - return rwlock->lock == 0; -} - /** * arch_read_lock() - acquire a read lock. */ diff --git a/arch/tile/include/asm/spinlock_64.h b/arch/tile/include/asm/spinlock_64.h index 9a2c2d605752..c802f48badf4 100644 --- a/arch/tile/include/asm/spinlock_64.h +++ b/arch/tile/include/asm/spinlock_64.h @@ -93,24 +93,6 @@ static inline int arch_write_val_locked(int val) return val < 0; /* Optimize "val & __WRITE_LOCK_BIT". */ } -/** - * read_can_lock - would read_trylock() succeed? - * @lock: the rwlock in question. - */ -static inline int arch_read_can_lock(arch_rwlock_t *rw) -{ - return !arch_write_val_locked(rw->lock); -} - -/** - * write_can_lock - would write_trylock() succeed? - * @lock: the rwlock in question. - */ -static inline int arch_write_can_lock(arch_rwlock_t *rw) -{ - return rw->lock == 0; -} - extern void __read_lock_failed(arch_rwlock_t *rw); static inline void arch_read_lock(arch_rwlock_t *rw) diff --git a/arch/xtensa/include/asm/spinlock.h b/arch/xtensa/include/asm/spinlock.h index 3bb49681ee24..d005af51e2e1 100644 --- a/arch/xtensa/include/asm/spinlock.h +++ b/arch/xtensa/include/asm/spinlock.h @@ -97,8 +97,6 @@ static inline void arch_spin_unlock(arch_spinlock_t *lock) * 0x80000000 one writer owns the rwlock, no other writers, no readers */ -#define arch_write_can_lock(x) ((x)->lock == 0) - static inline void arch_write_lock(arch_rwlock_t *rw) { unsigned long tmp; diff --git a/include/asm-generic/qrwlock.h b/include/asm-generic/qrwlock.h index 7d026bf27713..50925327b0a8 100644 --- a/include/asm-generic/qrwlock.h +++ b/include/asm-generic/qrwlock.h @@ -52,24 +52,6 @@ extern void queued_read_lock_slowpath(struct qrwlock *lock, u32 cnts); extern void queued_write_lock_slowpath(struct qrwlock *lock); -/** - * queued_read_can_lock- would read_trylock() succeed? - * @lock: Pointer to queue rwlock structure - */ -static inline int queued_read_can_lock(struct qrwlock *lock) -{ - return !(atomic_read(&lock->cnts) & _QW_WMASK); -} - -/** - * queued_write_can_lock- would write_trylock() succeed? - * @lock: Pointer to queue rwlock structure - */ -static inline int queued_write_can_lock(struct qrwlock *lock) -{ - return !atomic_read(&lock->cnts); -} - /** * queued_read_trylock - try to acquire read lock of a queue rwlock * @lock : Pointer to queue rwlock structure @@ -169,8 +151,6 @@ static inline void queued_write_unlock(struct qrwlock *lock) * Remapping rwlock architecture specific functions to the corresponding * queue rwlock functions. */ -#define arch_read_can_lock(l) queued_read_can_lock(l) -#define arch_write_can_lock(l) queued_write_can_lock(l) #define arch_read_lock(l) queued_read_lock(l) #define arch_write_lock(l) queued_write_lock(l) #define arch_read_trylock(l) queued_read_trylock(l) diff --git a/include/linux/rwlock.h b/include/linux/rwlock.h index bc2994ed66e1..766c5ca5cbd1 100644 --- a/include/linux/rwlock.h +++ b/include/linux/rwlock.h @@ -50,9 +50,6 @@ do { \ # define do_raw_write_unlock(rwlock) do {arch_write_unlock(&(rwlock)->raw_lock); __release(lock); } while (0) #endif -#define read_can_lock(rwlock) arch_read_can_lock(&(rwlock)->raw_lock) -#define write_can_lock(rwlock) arch_write_can_lock(&(rwlock)->raw_lock) - /* * Define the various rw_lock methods. Note we define these * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The various diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h index 69e079c5ff98..1e3e48041800 100644 --- a/include/linux/spinlock.h +++ b/include/linux/spinlock.h @@ -278,12 +278,6 @@ static inline void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock) 1 : ({ local_irq_restore(flags); 0; }); \ }) -/** - * raw_spin_can_lock - would raw_spin_trylock() succeed? - * @lock: the spinlock in question. - */ -#define raw_spin_can_lock(lock) (!raw_spin_is_locked(lock)) - /* Include rwlock functions */ #include @@ -396,11 +390,6 @@ static __always_inline int spin_is_contended(spinlock_t *lock) return raw_spin_is_contended(&lock->rlock); } -static __always_inline int spin_can_lock(spinlock_t *lock) -{ - return raw_spin_can_lock(&lock->rlock); -} - #define assert_spin_locked(lock) assert_raw_spin_locked(&(lock)->rlock) /* diff --git a/include/linux/spinlock_up.h b/include/linux/spinlock_up.h index 612fb530af41..901cf8f44388 100644 --- a/include/linux/spinlock_up.h +++ b/include/linux/spinlock_up.h @@ -77,7 +77,4 @@ static inline void arch_spin_unlock(arch_spinlock_t *lock) #define arch_spin_is_contended(lock) (((void)(lock), 0)) -#define arch_read_can_lock(lock) (((void)(lock), 1)) -#define arch_write_can_lock(lock) (((void)(lock), 1)) - #endif /* __LINUX_SPINLOCK_UP_H */ diff --git a/kernel/locking/spinlock.c b/kernel/locking/spinlock.c index 4b082b5cac9e..8fd48b5552a7 100644 --- a/kernel/locking/spinlock.c +++ b/kernel/locking/spinlock.c @@ -32,8 +32,6 @@ * include/linux/spinlock_api_smp.h */ #else -#define raw_read_can_lock(l) read_can_lock(l) -#define raw_write_can_lock(l) write_can_lock(l) /* * Some architectures can relax in favour of the CPU owning the lock. @@ -68,7 +66,7 @@ void __lockfunc __raw_##op##_lock(locktype##_t *lock) \ \ if (!(lock)->break_lock) \ (lock)->break_lock = 1; \ - while (!raw_##op##_can_lock(lock) && (lock)->break_lock)\ + while ((lock)->break_lock) \ arch_##op##_relax(&lock->raw_lock); \ } \ (lock)->break_lock = 0; \ @@ -88,7 +86,7 @@ unsigned long __lockfunc __raw_##op##_lock_irqsave(locktype##_t *lock) \ \ if (!(lock)->break_lock) \ (lock)->break_lock = 1; \ - while (!raw_##op##_can_lock(lock) && (lock)->break_lock)\ + while ((lock)->break_lock) \ arch_##op##_relax(&lock->raw_lock); \ } \ (lock)->break_lock = 0; \ From 0160fb177d484367e041ac251fca591a3e49660c Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Tue, 3 Oct 2017 19:25:28 +0100 Subject: [PATCH 14/70] locking/arch: Remove dummy arch_{read,spin,write}_relax() implementations arch_{read,spin,write}_relax() are defined as cpu_relax() by the core code, so architectures that can't do better (i.e. most of them) don't need to bother with the dummy definitions. Signed-off-by: Will Deacon Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1507055129-12300-3-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar --- arch/arc/include/asm/spinlock.h | 4 ---- arch/arm/include/asm/spinlock.h | 4 ---- arch/arm64/include/asm/spinlock.h | 4 ---- arch/blackfin/include/asm/spinlock.h | 4 ---- arch/ia64/include/asm/spinlock.h | 4 ---- arch/m32r/include/asm/spinlock.h | 4 ---- arch/metag/include/asm/spinlock.h | 4 ---- arch/metag/include/asm/spinlock_lnkget.h | 4 ---- arch/mips/include/asm/spinlock.h | 4 ---- arch/s390/include/asm/spinlock.h | 3 +++ arch/sh/include/asm/spinlock-cas.h | 4 ---- arch/sh/include/asm/spinlock-llsc.h | 4 ---- arch/sparc/include/asm/spinlock_32.h | 4 ---- arch/sparc/include/asm/spinlock_64.h | 4 ---- arch/x86/include/asm/spinlock.h | 4 ---- 15 files changed, 3 insertions(+), 56 deletions(-) diff --git a/arch/arc/include/asm/spinlock.h b/arch/arc/include/asm/spinlock.h index ce9bfcf1d870..f85bb585cdfc 100644 --- a/arch/arc/include/asm/spinlock.h +++ b/arch/arc/include/asm/spinlock.h @@ -413,8 +413,4 @@ static inline void arch_write_unlock(arch_rwlock_t *rw) #define arch_read_lock_flags(lock, flags) arch_read_lock(lock) #define arch_write_lock_flags(lock, flags) arch_write_lock(lock) -#define arch_spin_relax(lock) cpu_relax() -#define arch_read_relax(lock) cpu_relax() -#define arch_write_relax(lock) cpu_relax() - #endif /* __ASM_SPINLOCK_H */ diff --git a/arch/arm/include/asm/spinlock.h b/arch/arm/include/asm/spinlock.h index f5223260c73e..d40a28fcbc62 100644 --- a/arch/arm/include/asm/spinlock.h +++ b/arch/arm/include/asm/spinlock.h @@ -273,8 +273,4 @@ static inline int arch_read_trylock(arch_rwlock_t *rw) #define arch_read_lock_flags(lock, flags) arch_read_lock(lock) #define arch_write_lock_flags(lock, flags) arch_write_lock(lock) -#define arch_spin_relax(lock) cpu_relax() -#define arch_read_relax(lock) cpu_relax() -#define arch_write_relax(lock) cpu_relax() - #endif /* __ASM_SPINLOCK_H */ diff --git a/arch/arm64/include/asm/spinlock.h b/arch/arm64/include/asm/spinlock.h index 95ad7102b63c..1504f2b95c57 100644 --- a/arch/arm64/include/asm/spinlock.h +++ b/arch/arm64/include/asm/spinlock.h @@ -306,10 +306,6 @@ static inline int arch_read_trylock(arch_rwlock_t *rw) #define arch_read_lock_flags(lock, flags) arch_read_lock(lock) #define arch_write_lock_flags(lock, flags) arch_write_lock(lock) -#define arch_spin_relax(lock) cpu_relax() -#define arch_read_relax(lock) cpu_relax() -#define arch_write_relax(lock) cpu_relax() - /* See include/linux/spinlock.h */ #define smp_mb__after_spinlock() smp_mb() diff --git a/arch/blackfin/include/asm/spinlock.h b/arch/blackfin/include/asm/spinlock.h index 607ef98c0f6c..3885d12d9939 100644 --- a/arch/blackfin/include/asm/spinlock.h +++ b/arch/blackfin/include/asm/spinlock.h @@ -82,10 +82,6 @@ static inline void arch_write_unlock(arch_rwlock_t *rw) __raw_write_unlock_asm(&rw->lock); } -#define arch_spin_relax(lock) cpu_relax() -#define arch_read_relax(lock) cpu_relax() -#define arch_write_relax(lock) cpu_relax() - #endif #endif /* !__BFIN_SPINLOCK_H */ diff --git a/arch/ia64/include/asm/spinlock.h b/arch/ia64/include/asm/spinlock.h index c728dda59bd2..ed1e6212e9de 100644 --- a/arch/ia64/include/asm/spinlock.h +++ b/arch/ia64/include/asm/spinlock.h @@ -269,8 +269,4 @@ static inline int arch_read_trylock(arch_rwlock_t *x) return (u32)ia64_cmpxchg4_acq((__u32 *)(x), new.word, old.word) == old.word; } -#define arch_spin_relax(lock) cpu_relax() -#define arch_read_relax(lock) cpu_relax() -#define arch_write_relax(lock) cpu_relax() - #endif /* _ASM_IA64_SPINLOCK_H */ diff --git a/arch/m32r/include/asm/spinlock.h b/arch/m32r/include/asm/spinlock.h index 002601371b2f..6809a9bbd169 100644 --- a/arch/m32r/include/asm/spinlock.h +++ b/arch/m32r/include/asm/spinlock.h @@ -308,8 +308,4 @@ static inline int arch_write_trylock(arch_rwlock_t *lock) #define arch_read_lock_flags(lock, flags) arch_read_lock(lock) #define arch_write_lock_flags(lock, flags) arch_write_lock(lock) -#define arch_spin_relax(lock) cpu_relax() -#define arch_read_relax(lock) cpu_relax() -#define arch_write_relax(lock) cpu_relax() - #endif /* _ASM_M32R_SPINLOCK_H */ diff --git a/arch/metag/include/asm/spinlock.h b/arch/metag/include/asm/spinlock.h index ddf7fe5708a6..b5b4174cde5e 100644 --- a/arch/metag/include/asm/spinlock.h +++ b/arch/metag/include/asm/spinlock.h @@ -20,8 +20,4 @@ #define arch_read_lock_flags(lock, flags) arch_read_lock(lock) #define arch_write_lock_flags(lock, flags) arch_write_lock(lock) -#define arch_spin_relax(lock) cpu_relax() -#define arch_read_relax(lock) cpu_relax() -#define arch_write_relax(lock) cpu_relax() - #endif /* __ASM_SPINLOCK_H */ diff --git a/arch/metag/include/asm/spinlock_lnkget.h b/arch/metag/include/asm/spinlock_lnkget.h index 6a932a952d53..d5c334ddfd62 100644 --- a/arch/metag/include/asm/spinlock_lnkget.h +++ b/arch/metag/include/asm/spinlock_lnkget.h @@ -212,8 +212,4 @@ static inline int arch_read_trylock(arch_rwlock_t *rw) #define arch_read_lock_flags(lock, flags) arch_read_lock(lock) #define arch_write_lock_flags(lock, flags) arch_write_lock(lock) -#define arch_spin_relax(lock) cpu_relax() -#define arch_read_relax(lock) cpu_relax() -#define arch_write_relax(lock) cpu_relax() - #endif /* __ASM_SPINLOCK_LNKGET_H */ diff --git a/arch/mips/include/asm/spinlock.h b/arch/mips/include/asm/spinlock.h index a7d21da16b6a..4260d3f80d3a 100644 --- a/arch/mips/include/asm/spinlock.h +++ b/arch/mips/include/asm/spinlock.h @@ -16,8 +16,4 @@ #define arch_read_lock_flags(lock, flags) arch_read_lock(lock) #define arch_write_lock_flags(lock, flags) arch_write_lock(lock) -#define arch_spin_relax(lock) cpu_relax() -#define arch_read_relax(lock) cpu_relax() -#define arch_write_relax(lock) cpu_relax() - #endif /* _ASM_SPINLOCK_H */ diff --git a/arch/s390/include/asm/spinlock.h b/arch/s390/include/asm/spinlock.h index dc9c58ed9e4c..4eca60cc81e4 100644 --- a/arch/s390/include/asm/spinlock.h +++ b/arch/s390/include/asm/spinlock.h @@ -45,6 +45,7 @@ static inline void arch_spin_relax(arch_spinlock_t *lock) { arch_lock_relax(lock->lock); } +#define arch_spin_relax arch_spin_relax static inline u32 arch_spin_lockval(int cpu) { @@ -256,10 +257,12 @@ static inline void arch_read_relax(arch_rwlock_t *rw) { arch_lock_relax(rw->owner); } +#define arch_read_relax arch_read_relax static inline void arch_write_relax(arch_rwlock_t *rw) { arch_lock_relax(rw->owner); } +#define arch_write_relax arch_write_relax #endif /* __ASM_SPINLOCK_H */ diff --git a/arch/sh/include/asm/spinlock-cas.h b/arch/sh/include/asm/spinlock-cas.h index 315467834521..295993c2598e 100644 --- a/arch/sh/include/asm/spinlock-cas.h +++ b/arch/sh/include/asm/spinlock-cas.h @@ -93,8 +93,4 @@ static inline int arch_write_trylock(arch_rwlock_t *rw) #define arch_read_lock_flags(lock, flags) arch_read_lock(lock) #define arch_write_lock_flags(lock, flags) arch_write_lock(lock) -#define arch_spin_relax(lock) cpu_relax() -#define arch_read_relax(lock) cpu_relax() -#define arch_write_relax(lock) cpu_relax() - #endif /* __ASM_SH_SPINLOCK_CAS_H */ diff --git a/arch/sh/include/asm/spinlock-llsc.h b/arch/sh/include/asm/spinlock-llsc.h index 06be4a55f3c4..a6f9edd15317 100644 --- a/arch/sh/include/asm/spinlock-llsc.h +++ b/arch/sh/include/asm/spinlock-llsc.h @@ -200,8 +200,4 @@ static inline int arch_write_trylock(arch_rwlock_t *rw) #define arch_read_lock_flags(lock, flags) arch_read_lock(lock) #define arch_write_lock_flags(lock, flags) arch_write_lock(lock) -#define arch_spin_relax(lock) cpu_relax() -#define arch_read_relax(lock) cpu_relax() -#define arch_write_relax(lock) cpu_relax() - #endif /* __ASM_SH_SPINLOCK_LLSC_H */ diff --git a/arch/sparc/include/asm/spinlock_32.h b/arch/sparc/include/asm/spinlock_32.h index 76986b8f7dad..9d9129efd5d6 100644 --- a/arch/sparc/include/asm/spinlock_32.h +++ b/arch/sparc/include/asm/spinlock_32.h @@ -186,10 +186,6 @@ static inline int __arch_read_trylock(arch_rwlock_t *rw) #define arch_read_lock_flags(rw, flags) arch_read_lock(rw) #define arch_write_lock_flags(rw, flags) arch_write_lock(rw) -#define arch_spin_relax(lock) cpu_relax() -#define arch_read_relax(lock) cpu_relax() -#define arch_write_relax(lock) cpu_relax() - #endif /* !(__ASSEMBLY__) */ #endif /* __SPARC_SPINLOCK_H */ diff --git a/arch/sparc/include/asm/spinlock_64.h b/arch/sparc/include/asm/spinlock_64.h index f7028f5e1a5a..3b67705e1b74 100644 --- a/arch/sparc/include/asm/spinlock_64.h +++ b/arch/sparc/include/asm/spinlock_64.h @@ -16,10 +16,6 @@ #define arch_read_lock_flags(p, f) arch_read_lock(p) #define arch_write_lock_flags(p, f) arch_write_lock(p) -#define arch_spin_relax(lock) cpu_relax() -#define arch_read_relax(lock) cpu_relax() -#define arch_write_relax(lock) cpu_relax() - #endif /* !(__ASSEMBLY__) */ #endif /* !(__SPARC64_SPINLOCK_H) */ diff --git a/arch/x86/include/asm/spinlock.h b/arch/x86/include/asm/spinlock.h index 6d391909e864..a558c187f20c 100644 --- a/arch/x86/include/asm/spinlock.h +++ b/arch/x86/include/asm/spinlock.h @@ -44,8 +44,4 @@ #define arch_read_lock_flags(lock, flags) arch_read_lock(lock) #define arch_write_lock_flags(lock, flags) arch_write_lock(lock) -#define arch_spin_relax(lock) cpu_relax() -#define arch_read_relax(lock) cpu_relax() -#define arch_write_relax(lock) cpu_relax() - #endif /* _ASM_X86_SPINLOCK_H */ From a4c1887d4c1462b0ec5a8989f8ba3cdd9057a299 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Tue, 3 Oct 2017 19:25:29 +0100 Subject: [PATCH 15/70] locking/arch: Remove dummy arch_{read,spin,write}_lock_flags() implementations The arch_{read,spin,write}_lock_flags() macros are simply mapped to the non-flags versions by the majority of architectures, so do this in core code and remove the dummy implementations. Also remove the implementation in spinlock_up.h, since all callers of do_raw_spin_lock_flags() call local_irq_save(flags) anyway. Signed-off-by: Will Deacon Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1507055129-12300-4-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar --- arch/alpha/include/asm/spinlock.h | 4 ---- arch/arc/include/asm/spinlock.h | 4 ---- arch/arm/include/asm/spinlock.h | 5 ----- arch/arm64/include/asm/spinlock.h | 5 ----- arch/blackfin/include/asm/spinlock.h | 6 ------ arch/hexagon/include/asm/spinlock.h | 5 ----- arch/ia64/include/asm/spinlock.h | 5 +++-- arch/m32r/include/asm/spinlock.h | 4 ---- arch/metag/include/asm/spinlock.h | 5 ----- arch/metag/include/asm/spinlock_lnkget.h | 3 --- arch/mips/include/asm/spinlock.h | 3 --- arch/mn10300/include/asm/spinlock.h | 4 +--- arch/parisc/include/asm/spinlock.h | 4 +--- arch/powerpc/include/asm/spinlock.h | 4 +--- arch/s390/include/asm/spinlock.h | 4 +--- arch/sh/include/asm/spinlock-cas.h | 4 ---- arch/sh/include/asm/spinlock-llsc.h | 4 ---- arch/sparc/include/asm/spinlock_32.h | 4 ---- arch/sparc/include/asm/spinlock_64.h | 3 --- arch/tile/include/asm/spinlock_32.h | 6 ------ arch/tile/include/asm/spinlock_64.h | 6 ------ arch/x86/include/asm/spinlock.h | 3 --- arch/xtensa/include/asm/spinlock.h | 5 ----- include/asm-generic/qspinlock.h | 1 - include/linux/rwlock.h | 9 +++++++++ include/linux/spinlock.h | 4 ++++ include/linux/spinlock_up.h | 8 -------- 27 files changed, 20 insertions(+), 102 deletions(-) diff --git a/arch/alpha/include/asm/spinlock.h b/arch/alpha/include/asm/spinlock.h index 7bff6316b8bb..3e2b4a05cb0f 100644 --- a/arch/alpha/include/asm/spinlock.h +++ b/arch/alpha/include/asm/spinlock.h @@ -13,7 +13,6 @@ * We make no fairness assumptions. They have a cost. */ -#define arch_spin_lock_flags(lock, flags) arch_spin_lock(lock) #define arch_spin_is_locked(x) ((x)->lock != 0) static inline int arch_spin_value_unlocked(arch_spinlock_t lock) @@ -160,7 +159,4 @@ static inline void arch_write_unlock(arch_rwlock_t * lock) lock->lock = 0; } -#define arch_read_lock_flags(lock, flags) arch_read_lock(lock) -#define arch_write_lock_flags(lock, flags) arch_write_lock(lock) - #endif /* _ALPHA_SPINLOCK_H */ diff --git a/arch/arc/include/asm/spinlock.h b/arch/arc/include/asm/spinlock.h index f85bb585cdfc..2ba04a7db621 100644 --- a/arch/arc/include/asm/spinlock.h +++ b/arch/arc/include/asm/spinlock.h @@ -14,7 +14,6 @@ #include #define arch_spin_is_locked(x) ((x)->slock != __ARCH_SPIN_LOCK_UNLOCKED__) -#define arch_spin_lock_flags(lock, flags) arch_spin_lock(lock) #ifdef CONFIG_ARC_HAS_LLSC @@ -410,7 +409,4 @@ static inline void arch_write_unlock(arch_rwlock_t *rw) #endif -#define arch_read_lock_flags(lock, flags) arch_read_lock(lock) -#define arch_write_lock_flags(lock, flags) arch_write_lock(lock) - #endif /* __ASM_SPINLOCK_H */ diff --git a/arch/arm/include/asm/spinlock.h b/arch/arm/include/asm/spinlock.h index d40a28fcbc62..daa87212c9a1 100644 --- a/arch/arm/include/asm/spinlock.h +++ b/arch/arm/include/asm/spinlock.h @@ -52,8 +52,6 @@ static inline void dsb_sev(void) * memory. */ -#define arch_spin_lock_flags(lock, flags) arch_spin_lock(lock) - static inline void arch_spin_lock(arch_spinlock_t *lock) { unsigned long tmp; @@ -270,7 +268,4 @@ static inline int arch_read_trylock(arch_rwlock_t *rw) } } -#define arch_read_lock_flags(lock, flags) arch_read_lock(lock) -#define arch_write_lock_flags(lock, flags) arch_write_lock(lock) - #endif /* __ASM_SPINLOCK_H */ diff --git a/arch/arm64/include/asm/spinlock.h b/arch/arm64/include/asm/spinlock.h index 1504f2b95c57..aa51a38e46e4 100644 --- a/arch/arm64/include/asm/spinlock.h +++ b/arch/arm64/include/asm/spinlock.h @@ -27,8 +27,6 @@ * instructions. */ -#define arch_spin_lock_flags(lock, flags) arch_spin_lock(lock) - static inline void arch_spin_lock(arch_spinlock_t *lock) { unsigned int tmp; @@ -303,9 +301,6 @@ static inline int arch_read_trylock(arch_rwlock_t *rw) /* read_can_lock - would read_trylock() succeed? */ #define arch_read_can_lock(x) ((x)->lock < 0x80000000) -#define arch_read_lock_flags(lock, flags) arch_read_lock(lock) -#define arch_write_lock_flags(lock, flags) arch_write_lock(lock) - /* See include/linux/spinlock.h */ #define smp_mb__after_spinlock() smp_mb() diff --git a/arch/blackfin/include/asm/spinlock.h b/arch/blackfin/include/asm/spinlock.h index 3885d12d9939..839d1441af3a 100644 --- a/arch/blackfin/include/asm/spinlock.h +++ b/arch/blackfin/include/asm/spinlock.h @@ -36,8 +36,6 @@ static inline void arch_spin_lock(arch_spinlock_t *lock) __raw_spin_lock_asm(&lock->lock); } -#define arch_spin_lock_flags(lock, flags) arch_spin_lock(lock) - static inline int arch_spin_trylock(arch_spinlock_t *lock) { return __raw_spin_trylock_asm(&lock->lock); @@ -53,8 +51,6 @@ static inline void arch_read_lock(arch_rwlock_t *rw) __raw_read_lock_asm(&rw->lock); } -#define arch_read_lock_flags(lock, flags) arch_read_lock(lock) - static inline int arch_read_trylock(arch_rwlock_t *rw) { return __raw_read_trylock_asm(&rw->lock); @@ -70,8 +66,6 @@ static inline void arch_write_lock(arch_rwlock_t *rw) __raw_write_lock_asm(&rw->lock); } -#define arch_write_lock_flags(lock, flags) arch_write_lock(lock) - static inline int arch_write_trylock(arch_rwlock_t *rw) { return __raw_write_trylock_asm(&rw->lock); diff --git a/arch/hexagon/include/asm/spinlock.h b/arch/hexagon/include/asm/spinlock.h index 9f9414b9c303..48020863f53a 100644 --- a/arch/hexagon/include/asm/spinlock.h +++ b/arch/hexagon/include/asm/spinlock.h @@ -167,11 +167,6 @@ static inline unsigned int arch_spin_trylock(arch_spinlock_t *lock) /* * SMP spinlocks are intended to allow only a single CPU at the lock */ -#define arch_spin_lock_flags(lock, flags) arch_spin_lock(lock) - #define arch_spin_is_locked(x) ((x)->lock != 0) -#define arch_read_lock_flags(lock, flags) arch_read_lock(lock) -#define arch_write_lock_flags(lock, flags) arch_write_lock(lock) - #endif diff --git a/arch/ia64/include/asm/spinlock.h b/arch/ia64/include/asm/spinlock.h index ed1e6212e9de..35b31884863b 100644 --- a/arch/ia64/include/asm/spinlock.h +++ b/arch/ia64/include/asm/spinlock.h @@ -126,6 +126,7 @@ static __always_inline void arch_spin_lock_flags(arch_spinlock_t *lock, { arch_spin_lock(lock); } +#define arch_spin_lock_flags arch_spin_lock_flags #ifdef ASM_SUPPORTED @@ -153,6 +154,7 @@ arch_read_lock_flags(arch_rwlock_t *lock, unsigned long flags) : "p6", "p7", "r2", "memory"); } +#define arch_read_lock_flags arch_read_lock_flags #define arch_read_lock(lock) arch_read_lock_flags(lock, 0) #else /* !ASM_SUPPORTED */ @@ -205,6 +207,7 @@ arch_write_lock_flags(arch_rwlock_t *lock, unsigned long flags) : "ar.ccv", "p6", "p7", "r2", "r29", "memory"); } +#define arch_write_lock_flags arch_write_lock_flags #define arch_write_lock(rw) arch_write_lock_flags(rw, 0) #define arch_write_trylock(rw) \ @@ -228,8 +231,6 @@ static inline void arch_write_unlock(arch_rwlock_t *x) #else /* !ASM_SUPPORTED */ -#define arch_write_lock_flags(l, flags) arch_write_lock(l) - #define arch_write_lock(l) \ ({ \ __u64 ia64_val, ia64_set_val = ia64_dep_mi(-1, 0, 31, 1); \ diff --git a/arch/m32r/include/asm/spinlock.h b/arch/m32r/include/asm/spinlock.h index 6809a9bbd169..882203db8723 100644 --- a/arch/m32r/include/asm/spinlock.h +++ b/arch/m32r/include/asm/spinlock.h @@ -28,7 +28,6 @@ */ #define arch_spin_is_locked(x) (*(volatile int *)(&(x)->slock) <= 0) -#define arch_spin_lock_flags(lock, flags) arch_spin_lock(lock) /** * arch_spin_trylock - Try spin lock and return a result @@ -305,7 +304,4 @@ static inline int arch_write_trylock(arch_rwlock_t *lock) return 0; } -#define arch_read_lock_flags(lock, flags) arch_read_lock(lock) -#define arch_write_lock_flags(lock, flags) arch_write_lock(lock) - #endif /* _ASM_M32R_SPINLOCK_H */ diff --git a/arch/metag/include/asm/spinlock.h b/arch/metag/include/asm/spinlock.h index b5b4174cde5e..80e3e59172f2 100644 --- a/arch/metag/include/asm/spinlock.h +++ b/arch/metag/include/asm/spinlock.h @@ -15,9 +15,4 @@ * locked. */ -#define arch_spin_lock_flags(lock, flags) arch_spin_lock(lock) - -#define arch_read_lock_flags(lock, flags) arch_read_lock(lock) -#define arch_write_lock_flags(lock, flags) arch_write_lock(lock) - #endif /* __ASM_SPINLOCK_H */ diff --git a/arch/metag/include/asm/spinlock_lnkget.h b/arch/metag/include/asm/spinlock_lnkget.h index d5c334ddfd62..5708ac0a9d09 100644 --- a/arch/metag/include/asm/spinlock_lnkget.h +++ b/arch/metag/include/asm/spinlock_lnkget.h @@ -209,7 +209,4 @@ static inline int arch_read_trylock(arch_rwlock_t *rw) return tmp; } -#define arch_read_lock_flags(lock, flags) arch_read_lock(lock) -#define arch_write_lock_flags(lock, flags) arch_write_lock(lock) - #endif /* __ASM_SPINLOCK_LNKGET_H */ diff --git a/arch/mips/include/asm/spinlock.h b/arch/mips/include/asm/spinlock.h index 4260d3f80d3a..ee81297d9117 100644 --- a/arch/mips/include/asm/spinlock.h +++ b/arch/mips/include/asm/spinlock.h @@ -13,7 +13,4 @@ #include #include -#define arch_read_lock_flags(lock, flags) arch_read_lock(lock) -#define arch_write_lock_flags(lock, flags) arch_write_lock(lock) - #endif /* _ASM_SPINLOCK_H */ diff --git a/arch/mn10300/include/asm/spinlock.h b/arch/mn10300/include/asm/spinlock.h index 54f75dac8094..879cd0df53ba 100644 --- a/arch/mn10300/include/asm/spinlock.h +++ b/arch/mn10300/include/asm/spinlock.h @@ -84,6 +84,7 @@ static inline void arch_spin_lock_flags(arch_spinlock_t *lock, : "d" (flags), "a"(&lock->slock), "i"(EPSW_IE | MN10300_CLI_LEVEL) : "memory", "cc"); } +#define arch_spin_lock_flags arch_spin_lock_flags #ifdef __KERNEL__ @@ -171,9 +172,6 @@ static inline int arch_write_trylock(arch_rwlock_t *lock) return 0; } -#define arch_read_lock_flags(lock, flags) arch_read_lock(lock) -#define arch_write_lock_flags(lock, flags) arch_write_lock(lock) - #define _raw_spin_relax(lock) cpu_relax() #define _raw_read_relax(lock) cpu_relax() #define _raw_write_relax(lock) cpu_relax() diff --git a/arch/parisc/include/asm/spinlock.h b/arch/parisc/include/asm/spinlock.h index 136e1c9bb8a9..d66d7b1efc4e 100644 --- a/arch/parisc/include/asm/spinlock.h +++ b/arch/parisc/include/asm/spinlock.h @@ -31,6 +31,7 @@ static inline void arch_spin_lock_flags(arch_spinlock_t *x, cpu_relax(); mb(); } +#define arch_spin_lock_flags arch_spin_lock_flags static inline void arch_spin_unlock(arch_spinlock_t *x) { @@ -168,7 +169,4 @@ static __inline__ int arch_write_trylock(arch_rwlock_t *rw) return result; } -#define arch_read_lock_flags(lock, flags) arch_read_lock(lock) -#define arch_write_lock_flags(lock, flags) arch_write_lock(lock) - #endif /* __ASM_SPINLOCK_H */ diff --git a/arch/powerpc/include/asm/spinlock.h b/arch/powerpc/include/asm/spinlock.h index d83f4f755ad8..b9ebc3085fb7 100644 --- a/arch/powerpc/include/asm/spinlock.h +++ b/arch/powerpc/include/asm/spinlock.h @@ -161,6 +161,7 @@ void arch_spin_lock_flags(arch_spinlock_t *lock, unsigned long flags) local_irq_restore(flags_dis); } } +#define arch_spin_lock_flags arch_spin_lock_flags static inline void arch_spin_unlock(arch_spinlock_t *lock) { @@ -299,9 +300,6 @@ static inline void arch_write_unlock(arch_rwlock_t *rw) rw->lock = 0; } -#define arch_read_lock_flags(lock, flags) arch_read_lock(lock) -#define arch_write_lock_flags(lock, flags) arch_write_lock(lock) - #define arch_spin_relax(lock) __spin_yield(lock) #define arch_read_relax(lock) __rw_yield(lock) #define arch_write_relax(lock) __rw_yield(lock) diff --git a/arch/s390/include/asm/spinlock.h b/arch/s390/include/asm/spinlock.h index 4eca60cc81e4..9fa855f91e55 100644 --- a/arch/s390/include/asm/spinlock.h +++ b/arch/s390/include/asm/spinlock.h @@ -81,6 +81,7 @@ static inline void arch_spin_lock_flags(arch_spinlock_t *lp, if (!arch_spin_trylock_once(lp)) arch_spin_lock_wait_flags(lp, flags); } +#define arch_spin_lock_flags arch_spin_lock_flags static inline int arch_spin_trylock(arch_spinlock_t *lp) { @@ -114,9 +115,6 @@ static inline void arch_spin_unlock(arch_spinlock_t *lp) extern int _raw_read_trylock_retry(arch_rwlock_t *lp); extern int _raw_write_trylock_retry(arch_rwlock_t *lp); -#define arch_read_lock_flags(lock, flags) arch_read_lock(lock) -#define arch_write_lock_flags(lock, flags) arch_write_lock(lock) - static inline int arch_read_trylock_once(arch_rwlock_t *rw) { int old = ACCESS_ONCE(rw->lock); diff --git a/arch/sh/include/asm/spinlock-cas.h b/arch/sh/include/asm/spinlock-cas.h index 295993c2598e..270ee4d3e25b 100644 --- a/arch/sh/include/asm/spinlock-cas.h +++ b/arch/sh/include/asm/spinlock-cas.h @@ -27,7 +27,6 @@ static inline unsigned __sl_cas(volatile unsigned *p, unsigned old, unsigned new */ #define arch_spin_is_locked(x) ((x)->lock <= 0) -#define arch_spin_lock_flags(lock, flags) arch_spin_lock(lock) static inline void arch_spin_lock(arch_spinlock_t *lock) { @@ -90,7 +89,4 @@ static inline int arch_write_trylock(arch_rwlock_t *rw) return __sl_cas(&rw->lock, RW_LOCK_BIAS, 0) == RW_LOCK_BIAS; } -#define arch_read_lock_flags(lock, flags) arch_read_lock(lock) -#define arch_write_lock_flags(lock, flags) arch_write_lock(lock) - #endif /* __ASM_SH_SPINLOCK_CAS_H */ diff --git a/arch/sh/include/asm/spinlock-llsc.h b/arch/sh/include/asm/spinlock-llsc.h index a6f9edd15317..715595de286a 100644 --- a/arch/sh/include/asm/spinlock-llsc.h +++ b/arch/sh/include/asm/spinlock-llsc.h @@ -19,7 +19,6 @@ */ #define arch_spin_is_locked(x) ((x)->lock <= 0) -#define arch_spin_lock_flags(lock, flags) arch_spin_lock(lock) /* * Simple spin lock operations. There are two variants, one clears IRQ's @@ -197,7 +196,4 @@ static inline int arch_write_trylock(arch_rwlock_t *rw) return (oldval > (RW_LOCK_BIAS - 1)); } -#define arch_read_lock_flags(lock, flags) arch_read_lock(lock) -#define arch_write_lock_flags(lock, flags) arch_write_lock(lock) - #endif /* __ASM_SH_SPINLOCK_LLSC_H */ diff --git a/arch/sparc/include/asm/spinlock_32.h b/arch/sparc/include/asm/spinlock_32.h index 9d9129efd5d6..12bf857b471e 100644 --- a/arch/sparc/include/asm/spinlock_32.h +++ b/arch/sparc/include/asm/spinlock_32.h @@ -182,10 +182,6 @@ static inline int __arch_read_trylock(arch_rwlock_t *rw) res; \ }) -#define arch_spin_lock_flags(lock, flags) arch_spin_lock(lock) -#define arch_read_lock_flags(rw, flags) arch_read_lock(rw) -#define arch_write_lock_flags(rw, flags) arch_write_lock(rw) - #endif /* !(__ASSEMBLY__) */ #endif /* __SPARC_SPINLOCK_H */ diff --git a/arch/sparc/include/asm/spinlock_64.h b/arch/sparc/include/asm/spinlock_64.h index 3b67705e1b74..99b6e1c4f630 100644 --- a/arch/sparc/include/asm/spinlock_64.h +++ b/arch/sparc/include/asm/spinlock_64.h @@ -13,9 +13,6 @@ #include #include -#define arch_read_lock_flags(p, f) arch_read_lock(p) -#define arch_write_lock_flags(p, f) arch_write_lock(p) - #endif /* !(__ASSEMBLY__) */ #endif /* !(__SPARC64_SPINLOCK_H) */ diff --git a/arch/tile/include/asm/spinlock_32.h b/arch/tile/include/asm/spinlock_32.h index 91d05f21cba9..fb5313d77315 100644 --- a/arch/tile/include/asm/spinlock_32.h +++ b/arch/tile/include/asm/spinlock_32.h @@ -51,9 +51,6 @@ static inline int arch_spin_is_locked(arch_spinlock_t *lock) void arch_spin_lock(arch_spinlock_t *lock); -/* We cannot take an interrupt after getting a ticket, so don't enable them. */ -#define arch_spin_lock_flags(lock, flags) arch_spin_lock(lock) - int arch_spin_trylock(arch_spinlock_t *lock); static inline void arch_spin_unlock(arch_spinlock_t *lock) @@ -109,7 +106,4 @@ void arch_read_unlock(arch_rwlock_t *rwlock); */ void arch_write_unlock(arch_rwlock_t *rwlock); -#define arch_read_lock_flags(lock, flags) arch_read_lock(lock) -#define arch_write_lock_flags(lock, flags) arch_write_lock(lock) - #endif /* _ASM_TILE_SPINLOCK_32_H */ diff --git a/arch/tile/include/asm/spinlock_64.h b/arch/tile/include/asm/spinlock_64.h index c802f48badf4..5b616ef642a8 100644 --- a/arch/tile/include/asm/spinlock_64.h +++ b/arch/tile/include/asm/spinlock_64.h @@ -75,9 +75,6 @@ static inline void arch_spin_lock(arch_spinlock_t *lock) /* Try to get the lock, and return whether we succeeded. */ int arch_spin_trylock(arch_spinlock_t *lock); -/* We cannot take an interrupt after getting a ticket, so don't enable them. */ -#define arch_spin_lock_flags(lock, flags) arch_spin_lock(lock) - /* * Read-write spinlocks, allowing multiple readers * but only one writer. @@ -138,7 +135,4 @@ static inline int arch_write_trylock(arch_rwlock_t *rw) return 0; } -#define arch_read_lock_flags(lock, flags) arch_read_lock(lock) -#define arch_write_lock_flags(lock, flags) arch_write_lock(lock) - #endif /* _ASM_TILE_SPINLOCK_64_H */ diff --git a/arch/x86/include/asm/spinlock.h b/arch/x86/include/asm/spinlock.h index a558c187f20c..c6a6adf0a5c5 100644 --- a/arch/x86/include/asm/spinlock.h +++ b/arch/x86/include/asm/spinlock.h @@ -41,7 +41,4 @@ #include -#define arch_read_lock_flags(lock, flags) arch_read_lock(lock) -#define arch_write_lock_flags(lock, flags) arch_write_lock(lock) - #endif /* _ASM_X86_SPINLOCK_H */ diff --git a/arch/xtensa/include/asm/spinlock.h b/arch/xtensa/include/asm/spinlock.h index d005af51e2e1..c6e1290dcbb7 100644 --- a/arch/xtensa/include/asm/spinlock.h +++ b/arch/xtensa/include/asm/spinlock.h @@ -33,8 +33,6 @@ #define arch_spin_is_locked(x) ((x)->slock != 0) -#define arch_spin_lock_flags(lock, flags) arch_spin_lock(lock) - static inline void arch_spin_lock(arch_spinlock_t *lock) { unsigned long tmp; @@ -198,7 +196,4 @@ static inline void arch_read_unlock(arch_rwlock_t *rw) : "memory"); } -#define arch_read_lock_flags(lock, flags) arch_read_lock(lock) -#define arch_write_lock_flags(lock, flags) arch_write_lock(lock) - #endif /* _XTENSA_SPINLOCK_H */ diff --git a/include/asm-generic/qspinlock.h b/include/asm-generic/qspinlock.h index 66260777d644..b37b4ad7eb94 100644 --- a/include/asm-generic/qspinlock.h +++ b/include/asm-generic/qspinlock.h @@ -121,6 +121,5 @@ static __always_inline bool virt_spin_lock(struct qspinlock *lock) #define arch_spin_lock(l) queued_spin_lock(l) #define arch_spin_trylock(l) queued_spin_trylock(l) #define arch_spin_unlock(l) queued_spin_unlock(l) -#define arch_spin_lock_flags(l, f) queued_spin_lock(l) #endif /* __ASM_GENERIC_QSPINLOCK_H */ diff --git a/include/linux/rwlock.h b/include/linux/rwlock.h index 766c5ca5cbd1..3dcd617e65ae 100644 --- a/include/linux/rwlock.h +++ b/include/linux/rwlock.h @@ -38,6 +38,15 @@ do { \ extern int do_raw_write_trylock(rwlock_t *lock); extern void do_raw_write_unlock(rwlock_t *lock) __releases(lock); #else + +#ifndef arch_read_lock_flags +# define arch_read_lock_flags(lock, flags) arch_read_lock(lock) +#endif + +#ifndef arch_write_lock_flags +# define arch_write_lock_flags(lock, flags) arch_write_lock(lock) +#endif + # define do_raw_read_lock(rwlock) do {__acquire(lock); arch_read_lock(&(rwlock)->raw_lock); } while (0) # define do_raw_read_lock_flags(lock, flags) \ do {__acquire(lock); arch_read_lock_flags(&(lock)->raw_lock, *(flags)); } while (0) diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h index 1e3e48041800..4e202b00dd66 100644 --- a/include/linux/spinlock.h +++ b/include/linux/spinlock.h @@ -165,6 +165,10 @@ static inline void do_raw_spin_lock(raw_spinlock_t *lock) __acquires(lock) arch_spin_lock(&lock->raw_lock); } +#ifndef arch_spin_lock_flags +#define arch_spin_lock_flags(lock, flags) arch_spin_lock(lock) +#endif + static inline void do_raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long *flags) __acquires(lock) { diff --git a/include/linux/spinlock_up.h b/include/linux/spinlock_up.h index 901cf8f44388..0ac9112c1bbe 100644 --- a/include/linux/spinlock_up.h +++ b/include/linux/spinlock_up.h @@ -32,14 +32,6 @@ static inline void arch_spin_lock(arch_spinlock_t *lock) barrier(); } -static inline void -arch_spin_lock_flags(arch_spinlock_t *lock, unsigned long flags) -{ - local_irq_save(flags); - lock->slock = 0; - barrier(); -} - static inline int arch_spin_trylock(arch_spinlock_t *lock) { char oldval = lock->slock; From 58788a9b6060890e481c8111fac43d065560ebcb Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Wed, 18 Oct 2017 12:51:09 +0100 Subject: [PATCH 16/70] locking/arch, powerpc/rtas: Use arch_spin_lock() instead of arch_spin_lock_flags() arch_spin_lock_flags() is an internal part of the spinlock implementation and is no longer available when SMP=n and DEBUG_SPINLOCK=y, so the PPC RTAS code fails to compile in this configuration: arch/powerpc/kernel/rtas.c: In function 'lock_rtas': >> arch/powerpc/kernel/rtas.c:81:2: error: implicit declaration of function 'arch_spin_lock_flags' [-Werror=implicit-function-declaration] arch_spin_lock_flags(&rtas.lock, flags); ^~~~~~~~~~~~~~~~~~~~ Since there's no good reason to use arch_spin_lock_flags() here (the code in question already calls local_irq_save(flags)), switch it over to arch_spin_lock and get things building again. Reported-by: kbuild test robot Signed-off-by: Will Deacon Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1508327469-20231-1-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar --- arch/powerpc/kernel/rtas.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c index 1643e9e53655..3f1c4fcbe0aa 100644 --- a/arch/powerpc/kernel/rtas.c +++ b/arch/powerpc/kernel/rtas.c @@ -78,7 +78,7 @@ static unsigned long lock_rtas(void) local_irq_save(flags); preempt_disable(); - arch_spin_lock_flags(&rtas.lock, flags); + arch_spin_lock(&rtas.lock); return flags; } From 5cdda5117e125e0dbb020425cc55a4c143c6febc Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Wed, 18 Oct 2017 17:24:28 +0200 Subject: [PATCH 17/70] locking/static_keys: Improve uninitialized key warning Right now it says: static_key_disable_cpuslocked used before call to jump_label_init ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at kernel/jump_label.c:161 static_key_disable_cpuslocked+0x68/0x70 Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 4.14.0-rc5+ #1 Hardware name: SGI.COM C2112-4GP3/X10DRT-P-Series, BIOS 2.0a 05/09/2016 task: ffffffff81c0e480 task.stack: ffffffff81c00000 RIP: 0010:static_key_disable_cpuslocked+0x68/0x70 RSP: 0000:ffffffff81c03ef0 EFLAGS: 00010096 ORIG_RAX: 0000000000000000 RAX: 0000000000000041 RBX: ffffffff81c32680 RCX: ffffffff81c5cbf8 RDX: 0000000000000001 RSI: 0000000000000092 RDI: 0000000000000002 RBP: ffff88807fffd240 R08: 726f666562206465 R09: 0000000000000136 R10: 0000000000000000 R11: 696e695f6c656261 R12: ffffffff82158900 R13: ffffffff8215f760 R14: 0000000000000001 R15: 0000000000000008 FS: 0000000000000000(0000) GS:ffff883f7f400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff88807ffff000 CR3: 0000000001c09000 CR4: 00000000000606b0 Call Trace: static_key_disable+0x16/0x20 start_kernel+0x15a/0x45d ? load_ucode_intel_bsp+0x11/0x2d secondary_startup_64+0xa5/0xb0 Code: 48 c7 c7 a0 15 cf 81 e9 47 53 4b 00 48 89 df e8 5f fc ff ff eb e8 48 c7 c6 \ c0 97 83 81 48 c7 c7 d0 ff a2 81 31 c0 e8 c5 9d f5 ff <0f> ff eb a7 0f ff eb \ b0 e8 eb a2 4b 00 53 48 89 fb e8 42 0e f0 but it doesn't tell me which key it is. So dump the key's name too: static_key_disable_cpuslocked(): static key 'virt_spin_lock_key' used before call to jump_label_init() And that makes pinpointing which key is causing that a lot easier. include/linux/jump_label.h | 14 +++++++------- include/linux/jump_label_ratelimit.h | 6 +++--- kernel/jump_label.c | 14 +++++++------- 3 files changed, 17 insertions(+), 17 deletions(-) Signed-off-by: Borislav Petkov Reviewed-by: Steven Rostedt (VMware) Cc: Boris Ostrovsky Cc: Hannes Frederic Sowa Cc: Jason Baron Cc: Juergen Gross Cc: Linus Torvalds Cc: Paolo Bonzini Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20171018152428.ffjgak4o25f7ept6@pd.tnic Signed-off-by: Ingo Molnar --- include/linux/jump_label.h | 14 +++++++------- include/linux/jump_label_ratelimit.h | 6 +++--- kernel/jump_label.c | 14 +++++++------- 3 files changed, 17 insertions(+), 17 deletions(-) diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h index cd5861651b17..979a2f2d529b 100644 --- a/include/linux/jump_label.h +++ b/include/linux/jump_label.h @@ -81,9 +81,9 @@ extern bool static_key_initialized; -#define STATIC_KEY_CHECK_USE() WARN(!static_key_initialized, \ - "%s used before call to jump_label_init", \ - __func__) +#define STATIC_KEY_CHECK_USE(key) WARN(!static_key_initialized, \ + "%s(): static key '%pS' used before call to jump_label_init()", \ + __func__, (key)) #ifdef HAVE_JUMP_LABEL @@ -211,13 +211,13 @@ static __always_inline bool static_key_true(struct static_key *key) static inline void static_key_slow_inc(struct static_key *key) { - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); atomic_inc(&key->enabled); } static inline void static_key_slow_dec(struct static_key *key) { - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); atomic_dec(&key->enabled); } @@ -236,7 +236,7 @@ static inline int jump_label_apply_nops(struct module *mod) static inline void static_key_enable(struct static_key *key) { - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); if (atomic_read(&key->enabled) != 0) { WARN_ON_ONCE(atomic_read(&key->enabled) != 1); @@ -247,7 +247,7 @@ static inline void static_key_enable(struct static_key *key) static inline void static_key_disable(struct static_key *key) { - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); if (atomic_read(&key->enabled) != 1) { WARN_ON_ONCE(atomic_read(&key->enabled) != 0); diff --git a/include/linux/jump_label_ratelimit.h b/include/linux/jump_label_ratelimit.h index 23da3af459fe..93086df0a847 100644 --- a/include/linux/jump_label_ratelimit.h +++ b/include/linux/jump_label_ratelimit.h @@ -24,18 +24,18 @@ struct static_key_deferred { }; static inline void static_key_slow_dec_deferred(struct static_key_deferred *key) { - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); static_key_slow_dec(&key->key); } static inline void static_key_deferred_flush(struct static_key_deferred *key) { - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); } static inline void jump_label_rate_limit(struct static_key_deferred *key, unsigned long rl) { - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); } #endif /* HAVE_JUMP_LABEL */ #endif /* _LINUX_JUMP_LABEL_RATELIMIT_H */ diff --git a/kernel/jump_label.c b/kernel/jump_label.c index 0bf2e8f5244a..8ff4ca4665ff 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -83,7 +83,7 @@ static void static_key_slow_inc_cpuslocked(struct static_key *key) { int v, v1; - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); /* * Careful if we get concurrent static_key_slow_inc() calls; @@ -128,7 +128,7 @@ EXPORT_SYMBOL_GPL(static_key_slow_inc); void static_key_enable_cpuslocked(struct static_key *key) { - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); if (atomic_read(&key->enabled) > 0) { WARN_ON_ONCE(atomic_read(&key->enabled) != 1); @@ -158,7 +158,7 @@ EXPORT_SYMBOL_GPL(static_key_enable); void static_key_disable_cpuslocked(struct static_key *key) { - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); if (atomic_read(&key->enabled) != 1) { WARN_ON_ONCE(atomic_read(&key->enabled) != 0); @@ -224,21 +224,21 @@ static void jump_label_update_timeout(struct work_struct *work) void static_key_slow_dec(struct static_key *key) { - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); __static_key_slow_dec(key, 0, NULL); } EXPORT_SYMBOL_GPL(static_key_slow_dec); void static_key_slow_dec_deferred(struct static_key_deferred *key) { - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); __static_key_slow_dec(&key->key, key->timeout, &key->work); } EXPORT_SYMBOL_GPL(static_key_slow_dec_deferred); void static_key_deferred_flush(struct static_key_deferred *key) { - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); flush_delayed_work(&key->work); } EXPORT_SYMBOL_GPL(static_key_deferred_flush); @@ -246,7 +246,7 @@ EXPORT_SYMBOL_GPL(static_key_deferred_flush); void jump_label_rate_limit(struct static_key_deferred *key, unsigned long rl) { - STATIC_KEY_CHECK_USE(); + STATIC_KEY_CHECK_USE(key); key->timeout = rl; INIT_DELAYED_WORK(&key->work, jump_label_update_timeout); } From d15155824c5014803d91b829736d249c500bdda6 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Tue, 24 Oct 2017 11:22:46 +0100 Subject: [PATCH 18/70] linux/compiler.h: Split into compiler.h and compiler_types.h linux/compiler.h is included indirectly by linux/types.h via uapi/linux/types.h -> uapi/linux/posix_types.h -> linux/stddef.h -> uapi/linux/stddef.h and is needed to provide a proper definition of offsetof. Unfortunately, compiler.h requires a definition of smp_read_barrier_depends() for defining lockless_dereference() and soon for defining READ_ONCE(), which means that all users of READ_ONCE() will need to include asm/barrier.h to avoid splats such as: In file included from include/uapi/linux/stddef.h:1:0, from include/linux/stddef.h:4, from arch/h8300/kernel/asm-offsets.c:11: include/linux/list.h: In function 'list_empty': >> include/linux/compiler.h:343:2: error: implicit declaration of function 'smp_read_barrier_depends' [-Werror=implicit-function-declaration] smp_read_barrier_depends(); /* Enforce dependency ordering from x */ \ ^ A better alternative is to include asm/barrier.h in linux/compiler.h, but this requires a type definition for "bool" on some architectures (e.g. x86), which is defined later by linux/types.h. Type "bool" is also used directly in linux/compiler.h, so the whole thing is pretty fragile. This patch splits compiler.h in two: compiler_types.h contains type annotations, definitions and the compiler-specific parts, whereas compiler.h #includes compiler-types.h and additionally defines macros such as {READ,WRITE.ACCESS}_ONCE(). uapi/linux/stddef.h and linux/linkage.h are then moved over to include linux/compiler_types.h, which fixes the build for h8 and blackfin. Signed-off-by: Will Deacon Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1508840570-22169-2-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar --- arch/arm/include/asm/ptrace.h | 3 +- arch/sparc/include/asm/ptrace.h | 1 + arch/um/include/shared/init.h | 2 +- include/linux/compiler-clang.h | 2 +- include/linux/compiler-gcc.h | 2 +- include/linux/compiler-intel.h | 2 +- include/linux/compiler.h | 265 +----------------------------- include/linux/compiler_types.h | 274 ++++++++++++++++++++++++++++++++ include/linux/linkage.h | 2 +- include/uapi/linux/stddef.h | 2 +- scripts/headers_install.sh | 2 +- 11 files changed, 286 insertions(+), 271 deletions(-) create mode 100644 include/linux/compiler_types.h diff --git a/arch/arm/include/asm/ptrace.h b/arch/arm/include/asm/ptrace.h index e9c9a117bd25..c7cdbb43ae7c 100644 --- a/arch/arm/include/asm/ptrace.h +++ b/arch/arm/include/asm/ptrace.h @@ -126,8 +126,7 @@ extern unsigned long profile_pc(struct pt_regs *regs); /* * kprobe-based event tracer support */ -#include -#include +#include #define MAX_REG_OFFSET (offsetof(struct pt_regs, ARM_ORIG_r0)) extern int regs_query_register_offset(const char *name); diff --git a/arch/sparc/include/asm/ptrace.h b/arch/sparc/include/asm/ptrace.h index d73428e4333c..b383484edcd3 100644 --- a/arch/sparc/include/asm/ptrace.h +++ b/arch/sparc/include/asm/ptrace.h @@ -6,6 +6,7 @@ #if defined(__sparc__) && defined(__arch64__) #ifndef __ASSEMBLY__ +#include #include #include diff --git a/arch/um/include/shared/init.h b/arch/um/include/shared/init.h index 233e2593eee0..094e96ce653b 100644 --- a/arch/um/include/shared/init.h +++ b/arch/um/include/shared/init.h @@ -40,7 +40,7 @@ typedef int (*initcall_t)(void); typedef void (*exitcall_t)(void); -#include +#include /* These are for everybody (although not all archs will actually discard it in modules) */ diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h index de179993e039..5947a3e6c0e6 100644 --- a/include/linux/compiler-clang.h +++ b/include/linux/compiler-clang.h @@ -1,4 +1,4 @@ -#ifndef __LINUX_COMPILER_H +#ifndef __LINUX_COMPILER_TYPES_H #error "Please don't include directly, include instead." #endif diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h index 16d41de92ee3..ce8e965646ef 100644 --- a/include/linux/compiler-gcc.h +++ b/include/linux/compiler-gcc.h @@ -1,4 +1,4 @@ -#ifndef __LINUX_COMPILER_H +#ifndef __LINUX_COMPILER_TYPES_H #error "Please don't include directly, include instead." #endif diff --git a/include/linux/compiler-intel.h b/include/linux/compiler-intel.h index d4c71132d07f..e438ac89c692 100644 --- a/include/linux/compiler-intel.h +++ b/include/linux/compiler-intel.h @@ -1,4 +1,4 @@ -#ifndef __LINUX_COMPILER_H +#ifndef __LINUX_COMPILER_TYPES_H #error "Please don't include directly, include instead." #endif diff --git a/include/linux/compiler.h b/include/linux/compiler.h index e95a2631e545..08083186e54f 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -1,111 +1,12 @@ #ifndef __LINUX_COMPILER_H #define __LINUX_COMPILER_H +#include + #ifndef __ASSEMBLY__ -#ifdef __CHECKER__ -# define __user __attribute__((noderef, address_space(1))) -# define __kernel __attribute__((address_space(0))) -# define __safe __attribute__((safe)) -# define __force __attribute__((force)) -# define __nocast __attribute__((nocast)) -# define __iomem __attribute__((noderef, address_space(2))) -# define __must_hold(x) __attribute__((context(x,1,1))) -# define __acquires(x) __attribute__((context(x,0,1))) -# define __releases(x) __attribute__((context(x,1,0))) -# define __acquire(x) __context__(x,1) -# define __release(x) __context__(x,-1) -# define __cond_lock(x,c) ((c) ? ({ __acquire(x); 1; }) : 0) -# define __percpu __attribute__((noderef, address_space(3))) -# define __rcu __attribute__((noderef, address_space(4))) -# define __private __attribute__((noderef)) -extern void __chk_user_ptr(const volatile void __user *); -extern void __chk_io_ptr(const volatile void __iomem *); -# define ACCESS_PRIVATE(p, member) (*((typeof((p)->member) __force *) &(p)->member)) -#else /* __CHECKER__ */ -# ifdef STRUCTLEAK_PLUGIN -# define __user __attribute__((user)) -# else -# define __user -# endif -# define __kernel -# define __safe -# define __force -# define __nocast -# define __iomem -# define __chk_user_ptr(x) (void)0 -# define __chk_io_ptr(x) (void)0 -# define __builtin_warning(x, y...) (1) -# define __must_hold(x) -# define __acquires(x) -# define __releases(x) -# define __acquire(x) (void)0 -# define __release(x) (void)0 -# define __cond_lock(x,c) (c) -# define __percpu -# define __rcu -# define __private -# define ACCESS_PRIVATE(p, member) ((p)->member) -#endif /* __CHECKER__ */ - -/* Indirect macros required for expanded argument pasting, eg. __LINE__. */ -#define ___PASTE(a,b) a##b -#define __PASTE(a,b) ___PASTE(a,b) - #ifdef __KERNEL__ -#ifdef __GNUC__ -#include -#endif - -#if defined(CC_USING_HOTPATCH) && !defined(__CHECKER__) -#define notrace __attribute__((hotpatch(0,0))) -#else -#define notrace __attribute__((no_instrument_function)) -#endif - -/* Intel compiler defines __GNUC__. So we will overwrite implementations - * coming from above header files here - */ -#ifdef __INTEL_COMPILER -# include -#endif - -/* Clang compiler defines __GNUC__. So we will overwrite implementations - * coming from above header files here - */ -#ifdef __clang__ -#include -#endif - -/* - * Generic compiler-dependent macros required for kernel - * build go below this comment. Actual compiler/compiler version - * specific implementations come from the above header files - */ - -struct ftrace_branch_data { - const char *func; - const char *file; - unsigned line; - union { - struct { - unsigned long correct; - unsigned long incorrect; - }; - struct { - unsigned long miss; - unsigned long hit; - }; - unsigned long miss_hit[2]; - }; -}; - -struct ftrace_likely_data { - struct ftrace_branch_data data; - unsigned long constant; -}; - /* * Note: DISABLE_BRANCH_PROFILING can be used by special lowlevel code * to disable branch tracing on a per file basis. @@ -332,6 +233,7 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s * with an explicit memory barrier or atomic instruction that provides the * required ordering. */ +#include #define __READ_ONCE(x, check) \ ({ \ @@ -362,167 +264,6 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s #endif /* __ASSEMBLY__ */ -#ifdef __KERNEL__ -/* - * Allow us to mark functions as 'deprecated' and have gcc emit a nice - * warning for each use, in hopes of speeding the functions removal. - * Usage is: - * int __deprecated foo(void) - */ -#ifndef __deprecated -# define __deprecated /* unimplemented */ -#endif - -#ifdef MODULE -#define __deprecated_for_modules __deprecated -#else -#define __deprecated_for_modules -#endif - -#ifndef __must_check -#define __must_check -#endif - -#ifndef CONFIG_ENABLE_MUST_CHECK -#undef __must_check -#define __must_check -#endif -#ifndef CONFIG_ENABLE_WARN_DEPRECATED -#undef __deprecated -#undef __deprecated_for_modules -#define __deprecated -#define __deprecated_for_modules -#endif - -#ifndef __malloc -#define __malloc -#endif - -/* - * Allow us to avoid 'defined but not used' warnings on functions and data, - * as well as force them to be emitted to the assembly file. - * - * As of gcc 3.4, static functions that are not marked with attribute((used)) - * may be elided from the assembly file. As of gcc 3.4, static data not so - * marked will not be elided, but this may change in a future gcc version. - * - * NOTE: Because distributions shipped with a backported unit-at-a-time - * compiler in gcc 3.3, we must define __used to be __attribute__((used)) - * for gcc >=3.3 instead of 3.4. - * - * In prior versions of gcc, such functions and data would be emitted, but - * would be warned about except with attribute((unused)). - * - * Mark functions that are referenced only in inline assembly as __used so - * the code is emitted even though it appears to be unreferenced. - */ -#ifndef __used -# define __used /* unimplemented */ -#endif - -#ifndef __maybe_unused -# define __maybe_unused /* unimplemented */ -#endif - -#ifndef __always_unused -# define __always_unused /* unimplemented */ -#endif - -#ifndef noinline -#define noinline -#endif - -/* - * Rather then using noinline to prevent stack consumption, use - * noinline_for_stack instead. For documentation reasons. - */ -#define noinline_for_stack noinline - -#ifndef __always_inline -#define __always_inline inline -#endif - -#endif /* __KERNEL__ */ - -/* - * From the GCC manual: - * - * Many functions do not examine any values except their arguments, - * and have no effects except the return value. Basically this is - * just slightly more strict class than the `pure' attribute above, - * since function is not allowed to read global memory. - * - * Note that a function that has pointer arguments and examines the - * data pointed to must _not_ be declared `const'. Likewise, a - * function that calls a non-`const' function usually must not be - * `const'. It does not make sense for a `const' function to return - * `void'. - */ -#ifndef __attribute_const__ -# define __attribute_const__ /* unimplemented */ -#endif - -#ifndef __designated_init -# define __designated_init -#endif - -#ifndef __latent_entropy -# define __latent_entropy -#endif - -#ifndef __randomize_layout -# define __randomize_layout __designated_init -#endif - -#ifndef __no_randomize_layout -# define __no_randomize_layout -#endif - -#ifndef randomized_struct_fields_start -# define randomized_struct_fields_start -# define randomized_struct_fields_end -#endif - -/* - * Tell gcc if a function is cold. The compiler will assume any path - * directly leading to the call is unlikely. - */ - -#ifndef __cold -#define __cold -#endif - -/* Simple shorthand for a section definition */ -#ifndef __section -# define __section(S) __attribute__ ((__section__(#S))) -#endif - -#ifndef __visible -#define __visible -#endif - -#ifndef __nostackprotector -# define __nostackprotector -#endif - -/* - * Assume alignment of return value. - */ -#ifndef __assume_aligned -#define __assume_aligned(a, ...) -#endif - - -/* Are two types/vars the same type (ignoring qualifiers)? */ -#ifndef __same_type -# define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b)) -#endif - -/* Is this type a native word size -- useful for atomic operations */ -#ifndef __native_word -# define __native_word(t) (sizeof(t) == sizeof(char) || sizeof(t) == sizeof(short) || sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long)) -#endif - /* Compile time object size, -1 for unknown */ #ifndef __compiletime_object_size # define __compiletime_object_size(obj) -1 diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h new file mode 100644 index 000000000000..6b79a9bba9a7 --- /dev/null +++ b/include/linux/compiler_types.h @@ -0,0 +1,274 @@ +#ifndef __LINUX_COMPILER_TYPES_H +#define __LINUX_COMPILER_TYPES_H + +#ifndef __ASSEMBLY__ + +#ifdef __CHECKER__ +# define __user __attribute__((noderef, address_space(1))) +# define __kernel __attribute__((address_space(0))) +# define __safe __attribute__((safe)) +# define __force __attribute__((force)) +# define __nocast __attribute__((nocast)) +# define __iomem __attribute__((noderef, address_space(2))) +# define __must_hold(x) __attribute__((context(x,1,1))) +# define __acquires(x) __attribute__((context(x,0,1))) +# define __releases(x) __attribute__((context(x,1,0))) +# define __acquire(x) __context__(x,1) +# define __release(x) __context__(x,-1) +# define __cond_lock(x,c) ((c) ? ({ __acquire(x); 1; }) : 0) +# define __percpu __attribute__((noderef, address_space(3))) +# define __rcu __attribute__((noderef, address_space(4))) +# define __private __attribute__((noderef)) +extern void __chk_user_ptr(const volatile void __user *); +extern void __chk_io_ptr(const volatile void __iomem *); +# define ACCESS_PRIVATE(p, member) (*((typeof((p)->member) __force *) &(p)->member)) +#else /* __CHECKER__ */ +# ifdef STRUCTLEAK_PLUGIN +# define __user __attribute__((user)) +# else +# define __user +# endif +# define __kernel +# define __safe +# define __force +# define __nocast +# define __iomem +# define __chk_user_ptr(x) (void)0 +# define __chk_io_ptr(x) (void)0 +# define __builtin_warning(x, y...) (1) +# define __must_hold(x) +# define __acquires(x) +# define __releases(x) +# define __acquire(x) (void)0 +# define __release(x) (void)0 +# define __cond_lock(x,c) (c) +# define __percpu +# define __rcu +# define __private +# define ACCESS_PRIVATE(p, member) ((p)->member) +#endif /* __CHECKER__ */ + +/* Indirect macros required for expanded argument pasting, eg. __LINE__. */ +#define ___PASTE(a,b) a##b +#define __PASTE(a,b) ___PASTE(a,b) + +#ifdef __KERNEL__ + +#ifdef __GNUC__ +#include +#endif + +#if defined(CC_USING_HOTPATCH) && !defined(__CHECKER__) +#define notrace __attribute__((hotpatch(0,0))) +#else +#define notrace __attribute__((no_instrument_function)) +#endif + +/* Intel compiler defines __GNUC__. So we will overwrite implementations + * coming from above header files here + */ +#ifdef __INTEL_COMPILER +# include +#endif + +/* Clang compiler defines __GNUC__. So we will overwrite implementations + * coming from above header files here + */ +#ifdef __clang__ +#include +#endif + +/* + * Generic compiler-dependent macros required for kernel + * build go below this comment. Actual compiler/compiler version + * specific implementations come from the above header files + */ + +struct ftrace_branch_data { + const char *func; + const char *file; + unsigned line; + union { + struct { + unsigned long correct; + unsigned long incorrect; + }; + struct { + unsigned long miss; + unsigned long hit; + }; + unsigned long miss_hit[2]; + }; +}; + +struct ftrace_likely_data { + struct ftrace_branch_data data; + unsigned long constant; +}; + +#endif /* __KERNEL__ */ + +#endif /* __ASSEMBLY__ */ + +#ifdef __KERNEL__ +/* + * Allow us to mark functions as 'deprecated' and have gcc emit a nice + * warning for each use, in hopes of speeding the functions removal. + * Usage is: + * int __deprecated foo(void) + */ +#ifndef __deprecated +# define __deprecated /* unimplemented */ +#endif + +#ifdef MODULE +#define __deprecated_for_modules __deprecated +#else +#define __deprecated_for_modules +#endif + +#ifndef __must_check +#define __must_check +#endif + +#ifndef CONFIG_ENABLE_MUST_CHECK +#undef __must_check +#define __must_check +#endif +#ifndef CONFIG_ENABLE_WARN_DEPRECATED +#undef __deprecated +#undef __deprecated_for_modules +#define __deprecated +#define __deprecated_for_modules +#endif + +#ifndef __malloc +#define __malloc +#endif + +/* + * Allow us to avoid 'defined but not used' warnings on functions and data, + * as well as force them to be emitted to the assembly file. + * + * As of gcc 3.4, static functions that are not marked with attribute((used)) + * may be elided from the assembly file. As of gcc 3.4, static data not so + * marked will not be elided, but this may change in a future gcc version. + * + * NOTE: Because distributions shipped with a backported unit-at-a-time + * compiler in gcc 3.3, we must define __used to be __attribute__((used)) + * for gcc >=3.3 instead of 3.4. + * + * In prior versions of gcc, such functions and data would be emitted, but + * would be warned about except with attribute((unused)). + * + * Mark functions that are referenced only in inline assembly as __used so + * the code is emitted even though it appears to be unreferenced. + */ +#ifndef __used +# define __used /* unimplemented */ +#endif + +#ifndef __maybe_unused +# define __maybe_unused /* unimplemented */ +#endif + +#ifndef __always_unused +# define __always_unused /* unimplemented */ +#endif + +#ifndef noinline +#define noinline +#endif + +/* + * Rather then using noinline to prevent stack consumption, use + * noinline_for_stack instead. For documentation reasons. + */ +#define noinline_for_stack noinline + +#ifndef __always_inline +#define __always_inline inline +#endif + +#endif /* __KERNEL__ */ + +/* + * From the GCC manual: + * + * Many functions do not examine any values except their arguments, + * and have no effects except the return value. Basically this is + * just slightly more strict class than the `pure' attribute above, + * since function is not allowed to read global memory. + * + * Note that a function that has pointer arguments and examines the + * data pointed to must _not_ be declared `const'. Likewise, a + * function that calls a non-`const' function usually must not be + * `const'. It does not make sense for a `const' function to return + * `void'. + */ +#ifndef __attribute_const__ +# define __attribute_const__ /* unimplemented */ +#endif + +#ifndef __designated_init +# define __designated_init +#endif + +#ifndef __latent_entropy +# define __latent_entropy +#endif + +#ifndef __randomize_layout +# define __randomize_layout __designated_init +#endif + +#ifndef __no_randomize_layout +# define __no_randomize_layout +#endif + +#ifndef randomized_struct_fields_start +# define randomized_struct_fields_start +# define randomized_struct_fields_end +#endif + +/* + * Tell gcc if a function is cold. The compiler will assume any path + * directly leading to the call is unlikely. + */ + +#ifndef __cold +#define __cold +#endif + +/* Simple shorthand for a section definition */ +#ifndef __section +# define __section(S) __attribute__ ((__section__(#S))) +#endif + +#ifndef __visible +#define __visible +#endif + +#ifndef __nostackprotector +# define __nostackprotector +#endif + +/* + * Assume alignment of return value. + */ +#ifndef __assume_aligned +#define __assume_aligned(a, ...) +#endif + + +/* Are two types/vars the same type (ignoring qualifiers)? */ +#ifndef __same_type +# define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b)) +#endif + +/* Is this type a native word size -- useful for atomic operations */ +#ifndef __native_word +# define __native_word(t) (sizeof(t) == sizeof(char) || sizeof(t) == sizeof(short) || sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long)) +#endif + +#endif /* __LINUX_COMPILER_TYPES_H */ diff --git a/include/linux/linkage.h b/include/linux/linkage.h index a6a42dd02466..ebd61b80fed4 100644 --- a/include/linux/linkage.h +++ b/include/linux/linkage.h @@ -1,7 +1,7 @@ #ifndef _LINUX_LINKAGE_H #define _LINUX_LINKAGE_H -#include +#include #include #include #include diff --git a/include/uapi/linux/stddef.h b/include/uapi/linux/stddef.h index 621fa8ac4425..d1f7cb732dfc 100644 --- a/include/uapi/linux/stddef.h +++ b/include/uapi/linux/stddef.h @@ -1,4 +1,4 @@ -#include +#include #ifndef __always_inline #define __always_inline inline diff --git a/scripts/headers_install.sh b/scripts/headers_install.sh index fdebd66f8fc1..63b8cc26456a 100755 --- a/scripts/headers_install.sh +++ b/scripts/headers_install.sh @@ -33,7 +33,7 @@ do sed -r \ -e 's/([ \t(])(__user|__force|__iomem)[ \t]/\1/g' \ -e 's/__attribute_const__([ \t]|$)/\1/g' \ - -e 's@^#include @@' \ + -e 's@^#include @@' \ -e 's/(^|[^a-zA-Z0-9])__packed([^a-zA-Z0-9_]|$)/\1__attribute__((packed))\2/g' \ -e 's/(^|[ \t(])(inline|asm|volatile)([ \t(]|$)/\1__\2__\3/g' \ -e 's@#(ifndef|define|endif[ \t]*/[*])[ \t]*_UAPI@#\1 @' \ From 76ebbe78f7390aee075a7f3768af197ded1bdfbb Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Tue, 24 Oct 2017 11:22:47 +0100 Subject: [PATCH 19/70] locking/barriers: Add implicit smp_read_barrier_depends() to READ_ONCE() In preparation for the removal of lockless_dereference(), which is the same as READ_ONCE() on all architectures other than Alpha, add an implicit smp_read_barrier_depends() to READ_ONCE() so that it can be used to head dependency chains on all architectures. Signed-off-by: Will Deacon Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1508840570-22169-3-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar --- include/linux/compiler.h | 1 + 1 file changed, 1 insertion(+) diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 08083186e54f..7d7b77da9716 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -242,6 +242,7 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s __read_once_size(&(x), __u.__c, sizeof(x)); \ else \ __read_once_size_nocheck(&(x), __u.__c, sizeof(x)); \ + smp_read_barrier_depends(); /* Enforce dependency ordering from x */ \ __u.__val; \ }) #define READ_ONCE(x) __READ_ONCE(x, 1) From 506458efaf153c1ea480591c5602a5a3ba5a3b76 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Tue, 24 Oct 2017 11:22:48 +0100 Subject: [PATCH 20/70] locking/barriers: Convert users of lockless_dereference() to READ_ONCE() READ_ONCE() now has an implicit smp_read_barrier_depends() call, so it can be used instead of lockless_dereference() without any change in semantics. Signed-off-by: Will Deacon Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1508840570-22169-4-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar --- arch/x86/events/core.c | 2 +- arch/x86/include/asm/mmu_context.h | 4 ++-- arch/x86/kernel/ldt.c | 2 +- drivers/md/dm-mpath.c | 20 ++++++++++---------- fs/dcache.c | 4 ++-- fs/overlayfs/ovl_entry.h | 2 +- fs/overlayfs/readdir.c | 2 +- include/linux/rculist.h | 4 ++-- include/linux/rcupdate.h | 4 ++-- kernel/events/core.c | 4 ++-- kernel/seccomp.c | 2 +- kernel/task_work.c | 2 +- mm/slab.h | 2 +- 13 files changed, 27 insertions(+), 27 deletions(-) diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c index 80534d3c2480..589af1eec7c1 100644 --- a/arch/x86/events/core.c +++ b/arch/x86/events/core.c @@ -2371,7 +2371,7 @@ static unsigned long get_segment_base(unsigned int segment) struct ldt_struct *ldt; /* IRQs are off, so this synchronizes with smp_store_release */ - ldt = lockless_dereference(current->active_mm->context.ldt); + ldt = READ_ONCE(current->active_mm->context.ldt); if (!ldt || idx >= ldt->nr_entries) return 0; diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h index 3c856a15b98e..efc530642f7d 100644 --- a/arch/x86/include/asm/mmu_context.h +++ b/arch/x86/include/asm/mmu_context.h @@ -72,8 +72,8 @@ static inline void load_mm_ldt(struct mm_struct *mm) #ifdef CONFIG_MODIFY_LDT_SYSCALL struct ldt_struct *ldt; - /* lockless_dereference synchronizes with smp_store_release */ - ldt = lockless_dereference(mm->context.ldt); + /* READ_ONCE synchronizes with smp_store_release */ + ldt = READ_ONCE(mm->context.ldt); /* * Any change to mm->context.ldt is followed by an IPI to all diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c index f0e64db18ac8..0a21390642c4 100644 --- a/arch/x86/kernel/ldt.c +++ b/arch/x86/kernel/ldt.c @@ -101,7 +101,7 @@ static void finalize_ldt_struct(struct ldt_struct *ldt) static void install_ldt(struct mm_struct *current_mm, struct ldt_struct *ldt) { - /* Synchronizes with lockless_dereference in load_mm_ldt. */ + /* Synchronizes with READ_ONCE in load_mm_ldt. */ smp_store_release(¤t_mm->context.ldt, ldt); /* Activate the LDT for all CPUs using current_mm. */ diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index 11f273d2f018..3f88c9d32f7e 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -366,7 +366,7 @@ static struct pgpath *choose_path_in_pg(struct multipath *m, pgpath = path_to_pgpath(path); - if (unlikely(lockless_dereference(m->current_pg) != pg)) { + if (unlikely(READ_ONCE(m->current_pg) != pg)) { /* Only update current_pgpath if pg changed */ spin_lock_irqsave(&m->lock, flags); m->current_pgpath = pgpath; @@ -390,7 +390,7 @@ static struct pgpath *choose_pgpath(struct multipath *m, size_t nr_bytes) } /* Were we instructed to switch PG? */ - if (lockless_dereference(m->next_pg)) { + if (READ_ONCE(m->next_pg)) { spin_lock_irqsave(&m->lock, flags); pg = m->next_pg; if (!pg) { @@ -406,7 +406,7 @@ static struct pgpath *choose_pgpath(struct multipath *m, size_t nr_bytes) /* Don't change PG until it has no remaining paths */ check_current_pg: - pg = lockless_dereference(m->current_pg); + pg = READ_ONCE(m->current_pg); if (pg) { pgpath = choose_path_in_pg(m, pg, nr_bytes); if (!IS_ERR_OR_NULL(pgpath)) @@ -473,7 +473,7 @@ static int multipath_clone_and_map(struct dm_target *ti, struct request *rq, struct request *clone; /* Do we need to select a new pgpath? */ - pgpath = lockless_dereference(m->current_pgpath); + pgpath = READ_ONCE(m->current_pgpath); if (!pgpath || !test_bit(MPATHF_QUEUE_IO, &m->flags)) pgpath = choose_pgpath(m, nr_bytes); @@ -535,7 +535,7 @@ static int __multipath_map_bio(struct multipath *m, struct bio *bio, struct dm_m bool queue_io; /* Do we need to select a new pgpath? */ - pgpath = lockless_dereference(m->current_pgpath); + pgpath = READ_ONCE(m->current_pgpath); queue_io = test_bit(MPATHF_QUEUE_IO, &m->flags); if (!pgpath || !queue_io) pgpath = choose_pgpath(m, nr_bytes); @@ -1804,7 +1804,7 @@ static int multipath_prepare_ioctl(struct dm_target *ti, struct pgpath *current_pgpath; int r; - current_pgpath = lockless_dereference(m->current_pgpath); + current_pgpath = READ_ONCE(m->current_pgpath); if (!current_pgpath) current_pgpath = choose_pgpath(m, 0); @@ -1826,7 +1826,7 @@ static int multipath_prepare_ioctl(struct dm_target *ti, } if (r == -ENOTCONN) { - if (!lockless_dereference(m->current_pg)) { + if (!READ_ONCE(m->current_pg)) { /* Path status changed, redo selection */ (void) choose_pgpath(m, 0); } @@ -1895,9 +1895,9 @@ static int multipath_busy(struct dm_target *ti) return (m->queue_mode != DM_TYPE_MQ_REQUEST_BASED); /* Guess which priority_group will be used at next mapping time */ - pg = lockless_dereference(m->current_pg); - next_pg = lockless_dereference(m->next_pg); - if (unlikely(!lockless_dereference(m->current_pgpath) && next_pg)) + pg = READ_ONCE(m->current_pg); + next_pg = READ_ONCE(m->next_pg); + if (unlikely(!READ_ONCE(m->current_pgpath) && next_pg)) pg = next_pg; if (!pg) { diff --git a/fs/dcache.c b/fs/dcache.c index f90141387f01..34c852af215c 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -231,7 +231,7 @@ static inline int dentry_cmp(const struct dentry *dentry, const unsigned char *c { /* * Be careful about RCU walk racing with rename: - * use 'lockless_dereference' to fetch the name pointer. + * use 'READ_ONCE' to fetch the name pointer. * * NOTE! Even if a rename will mean that the length * was not loaded atomically, we don't care. The @@ -245,7 +245,7 @@ static inline int dentry_cmp(const struct dentry *dentry, const unsigned char *c * early because the data cannot match (there can * be no NUL in the ct/tcount data) */ - const unsigned char *cs = lockless_dereference(dentry->d_name.name); + const unsigned char *cs = READ_ONCE(dentry->d_name.name); return dentry_string_cmp(cs, ct, tcount); } diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h index 25d9b5adcd42..36b49bd09264 100644 --- a/fs/overlayfs/ovl_entry.h +++ b/fs/overlayfs/ovl_entry.h @@ -77,5 +77,5 @@ static inline struct ovl_inode *OVL_I(struct inode *inode) static inline struct dentry *ovl_upperdentry_dereference(struct ovl_inode *oi) { - return lockless_dereference(oi->__upperdentry); + return READ_ONCE(oi->__upperdentry); } diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c index 0f85ee9c3268..c67a7703296b 100644 --- a/fs/overlayfs/readdir.c +++ b/fs/overlayfs/readdir.c @@ -754,7 +754,7 @@ static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end, if (!od->is_upper && OVL_TYPE_UPPER(ovl_path_type(dentry))) { struct inode *inode = file_inode(file); - realfile = lockless_dereference(od->upperfile); + realfile = READ_ONCE(od->upperfile); if (!realfile) { struct path upperpath; diff --git a/include/linux/rculist.h b/include/linux/rculist.h index 2bea1d5e9930..5ed091c064b2 100644 --- a/include/linux/rculist.h +++ b/include/linux/rculist.h @@ -274,7 +274,7 @@ static inline void list_splice_tail_init_rcu(struct list_head *list, * primitives such as list_add_rcu() as long as it's guarded by rcu_read_lock(). */ #define list_entry_rcu(ptr, type, member) \ - container_of(lockless_dereference(ptr), type, member) + container_of(READ_ONCE(ptr), type, member) /* * Where are list_empty_rcu() and list_first_entry_rcu()? @@ -367,7 +367,7 @@ static inline void list_splice_tail_init_rcu(struct list_head *list, * example is when items are added to the list, but never deleted. */ #define list_entry_lockless(ptr, type, member) \ - container_of((typeof(ptr))lockless_dereference(ptr), type, member) + container_of((typeof(ptr))READ_ONCE(ptr), type, member) /** * list_for_each_entry_lockless - iterate over rcu list of given type diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 1a9f70d44af9..a6ddc42f87a5 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -346,7 +346,7 @@ static inline void rcu_preempt_sleep_check(void) { } #define __rcu_dereference_check(p, c, space) \ ({ \ /* Dependency order vs. p above. */ \ - typeof(*p) *________p1 = (typeof(*p) *__force)lockless_dereference(p); \ + typeof(*p) *________p1 = (typeof(*p) *__force)READ_ONCE(p); \ RCU_LOCKDEP_WARN(!(c), "suspicious rcu_dereference_check() usage"); \ rcu_dereference_sparse(p, space); \ ((typeof(*p) __force __kernel *)(________p1)); \ @@ -360,7 +360,7 @@ static inline void rcu_preempt_sleep_check(void) { } #define rcu_dereference_raw(p) \ ({ \ /* Dependency order vs. p above. */ \ - typeof(p) ________p1 = lockless_dereference(p); \ + typeof(p) ________p1 = READ_ONCE(p); \ ((typeof(*p) __force __kernel *)(________p1)); \ }) diff --git a/kernel/events/core.c b/kernel/events/core.c index 9d93db81fa36..824a583079a1 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -4231,7 +4231,7 @@ static void perf_remove_from_owner(struct perf_event *event) * indeed free this event, otherwise we need to serialize on * owner->perf_event_mutex. */ - owner = lockless_dereference(event->owner); + owner = READ_ONCE(event->owner); if (owner) { /* * Since delayed_put_task_struct() also drops the last @@ -4328,7 +4328,7 @@ int perf_event_release_kernel(struct perf_event *event) * Cannot change, child events are not migrated, see the * comment with perf_event_ctx_lock_nested(). */ - ctx = lockless_dereference(child->ctx); + ctx = READ_ONCE(child->ctx); /* * Since child_mutex nests inside ctx::mutex, we must jump * through hoops. We start by grabbing a reference on the ctx. diff --git a/kernel/seccomp.c b/kernel/seccomp.c index 0ae832e13b97..8ac79355915b 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -189,7 +189,7 @@ static u32 seccomp_run_filters(const struct seccomp_data *sd, u32 ret = SECCOMP_RET_ALLOW; /* Make sure cross-thread synced filter points somewhere sane. */ struct seccomp_filter *f = - lockless_dereference(current->seccomp.filter); + READ_ONCE(current->seccomp.filter); /* Ensure unexpected behavior doesn't result in failing open. */ if (unlikely(WARN_ON(f == NULL))) diff --git a/kernel/task_work.c b/kernel/task_work.c index 836a72a66fba..9a9f262fc53d 100644 --- a/kernel/task_work.c +++ b/kernel/task_work.c @@ -67,7 +67,7 @@ task_work_cancel(struct task_struct *task, task_work_func_t func) * we raced with task_work_run(), *pprev == NULL/exited. */ raw_spin_lock_irqsave(&task->pi_lock, flags); - while ((work = lockless_dereference(*pprev))) { + while ((work = READ_ONCE(*pprev))) { if (work->func != func) pprev = &work->next; else if (cmpxchg(pprev, work, work->next) == work) diff --git a/mm/slab.h b/mm/slab.h index 073362816acc..8894f811a89d 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -258,7 +258,7 @@ cache_from_memcg_idx(struct kmem_cache *s, int idx) * memcg_caches issues a write barrier to match this (see * memcg_create_kmem_cache()). */ - cachep = lockless_dereference(arr->entries[idx]); + cachep = READ_ONCE(arr->entries[idx]); rcu_read_unlock(); return cachep; From 59ecbbe7b31cd2d86ff9a9f461a00f7e7533aedc Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Tue, 24 Oct 2017 11:22:49 +0100 Subject: [PATCH 21/70] locking/barriers: Kill lockless_dereference() lockless_dereference() is a nice idea, but it gained little traction in kernel code since its introduction three years ago. This is partly because it's a pain to type, but also because using READ_ONCE() instead has worked correctly on all architectures apart from Alpha, which is a fully supported but somewhat niche architecture these days. Now that READ_ONCE() has been upgraded to contain an implicit smp_read_barrier_depends() and the few callers of lockless_dereference() have been converted, we can remove lockless_dereference() altogether. Signed-off-by: Will Deacon Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1508840570-22169-5-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar --- Documentation/memory-barriers.txt | 12 ----------- .../translations/ko_KR/memory-barriers.txt | 12 ----------- include/linux/compiler.h | 20 ------------------- 3 files changed, 44 deletions(-) diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt index b759a60624fd..470a682f3fa4 100644 --- a/Documentation/memory-barriers.txt +++ b/Documentation/memory-barriers.txt @@ -1886,18 +1886,6 @@ There are some more advanced barrier functions: See Documentation/atomic_{t,bitops}.txt for more information. - (*) lockless_dereference(); - - This can be thought of as a pointer-fetch wrapper around the - smp_read_barrier_depends() data-dependency barrier. - - This is also similar to rcu_dereference(), but in cases where - object lifetime is handled by some mechanism other than RCU, for - example, when the objects removed only when the system goes down. - In addition, lockless_dereference() is used in some data structures - that can be used both with and without RCU. - - (*) dma_wmb(); (*) dma_rmb(); diff --git a/Documentation/translations/ko_KR/memory-barriers.txt b/Documentation/translations/ko_KR/memory-barriers.txt index a7a813258013..ec3b46e27b7a 100644 --- a/Documentation/translations/ko_KR/memory-barriers.txt +++ b/Documentation/translations/ko_KR/memory-barriers.txt @@ -1858,18 +1858,6 @@ Mandatory 배리어들은 SMP 시스템에서도 UP 시스템에서도 SMP 효 참고하세요. - (*) lockless_dereference(); - - 이 함수는 smp_read_barrier_depends() 데이터 의존성 배리어를 사용하는 - 포인터 읽어오기 래퍼(wrapper) 함수로 생각될 수 있습니다. - - 객체의 라이프타임이 RCU 외의 메커니즘으로 관리된다는 점을 제외하면 - rcu_dereference() 와도 유사한데, 예를 들면 객체가 시스템이 꺼질 때에만 - 제거되는 경우 등입니다. 또한, lockless_dereference() 은 RCU 와 함께 - 사용될수도, RCU 없이 사용될 수도 있는 일부 데이터 구조에 사용되고 - 있습니다. - - (*) dma_wmb(); (*) dma_rmb(); diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 7d7b77da9716..5a1cab48442c 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -346,24 +346,4 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s (volatile typeof(x) *)&(x); }) #define ACCESS_ONCE(x) (*__ACCESS_ONCE(x)) -/** - * lockless_dereference() - safely load a pointer for later dereference - * @p: The pointer to load - * - * Similar to rcu_dereference(), but for situations where the pointed-to - * object's lifetime is managed by something other than RCU. That - * "something other" might be reference counting or simple immortality. - * - * The seemingly unused variable ___typecheck_p validates that @p is - * indeed a pointer type by using a pointer to typeof(*p) as the type. - * Taking a pointer to typeof(*p) again is needed in case p is void *. - */ -#define lockless_dereference(p) \ -({ \ - typeof(p) _________p1 = READ_ONCE(p); \ - typeof(*(p)) *___typecheck_p __maybe_unused; \ - smp_read_barrier_depends(); /* Dependency order vs. p above. */ \ - (_________p1); \ -}) - #endif /* __LINUX_COMPILER_H */ From 5a8897cc7631fa544d079c443800f4420d1b173f Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Tue, 24 Oct 2017 11:22:50 +0100 Subject: [PATCH 22/70] locking/atomics/alpha: Add smp_read_barrier_depends() to _release()/_relaxed() atomics As part of the fight against smp_read_barrier_depends(), we require dependency ordering to be preserved when a dependency is headed by a load performed using an atomic operation. This patch adds smp_read_barrier_depends() to the _release() and _relaxed() atomics on alpha, which otherwise lack anything to enforce dependency ordering. Signed-off-by: Will Deacon Signed-off-by: Paul E. McKenney Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1508840570-22169-6-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar --- arch/alpha/include/asm/atomic.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/alpha/include/asm/atomic.h b/arch/alpha/include/asm/atomic.h index 498933a7df97..16961a3f45ba 100644 --- a/arch/alpha/include/asm/atomic.h +++ b/arch/alpha/include/asm/atomic.h @@ -13,6 +13,15 @@ * than regular operations. */ +/* + * To ensure dependency ordering is preserved for the _relaxed and + * _release atomics, an smp_read_barrier_depends() is unconditionally + * inserted into the _relaxed variants, which are used to build the + * barriered versions. To avoid redundant back-to-back fences, we can + * define the _acquire and _fence versions explicitly. + */ +#define __atomic_op_acquire(op, args...) op##_relaxed(args) +#define __atomic_op_fence __atomic_op_release #define ATOMIC_INIT(i) { (i) } #define ATOMIC64_INIT(i) { (i) } @@ -60,6 +69,7 @@ static inline int atomic_##op##_return_relaxed(int i, atomic_t *v) \ ".previous" \ :"=&r" (temp), "=m" (v->counter), "=&r" (result) \ :"Ir" (i), "m" (v->counter) : "memory"); \ + smp_read_barrier_depends(); \ return result; \ } @@ -77,6 +87,7 @@ static inline int atomic_fetch_##op##_relaxed(int i, atomic_t *v) \ ".previous" \ :"=&r" (temp), "=m" (v->counter), "=&r" (result) \ :"Ir" (i), "m" (v->counter) : "memory"); \ + smp_read_barrier_depends(); \ return result; \ } @@ -111,6 +122,7 @@ static __inline__ long atomic64_##op##_return_relaxed(long i, atomic64_t * v) \ ".previous" \ :"=&r" (temp), "=m" (v->counter), "=&r" (result) \ :"Ir" (i), "m" (v->counter) : "memory"); \ + smp_read_barrier_depends(); \ return result; \ } @@ -128,6 +140,7 @@ static __inline__ long atomic64_fetch_##op##_relaxed(long i, atomic64_t * v) \ ".previous" \ :"=&r" (temp), "=m" (v->counter), "=&r" (result) \ :"Ir" (i), "m" (v->counter) : "memory"); \ + smp_read_barrier_depends(); \ return result; \ } From e0d02285f16e8d5810f3d5d5e8a5886ca0015d3b Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Thu, 12 Oct 2017 13:20:47 +0100 Subject: [PATCH 23/70] locking/qrwlock: Use 'struct qrwlock' instead of 'struct __qrwlock' There's no good reason to keep the internal structure of struct qrwlock hidden from qrwlock.h, particularly as it's actually needed for unlock and ends up being abstracted independently behind the __qrwlock_write_byte() function. Stop pretending we can hide this stuff, and move the __qrwlock definition into qrwlock, removing the __qrwlock_write_byte() nastiness and using the same struct definition everywhere instead. Signed-off-by: Will Deacon Acked-by: Peter Zijlstra Cc: Boqun Feng Cc: Jeremy.Linton@arm.com Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Thomas Gleixner Cc: Waiman Long Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1507810851-306-2-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar --- include/asm-generic/qrwlock.h | 12 +----------- include/asm-generic/qrwlock_types.h | 15 +++++++++++++-- kernel/locking/qrwlock.c | 26 ++------------------------ 3 files changed, 16 insertions(+), 37 deletions(-) diff --git a/include/asm-generic/qrwlock.h b/include/asm-generic/qrwlock.h index 50925327b0a8..02c0a768e6b0 100644 --- a/include/asm-generic/qrwlock.h +++ b/include/asm-generic/qrwlock.h @@ -128,23 +128,13 @@ static inline void queued_read_unlock(struct qrwlock *lock) (void)atomic_sub_return_release(_QR_BIAS, &lock->cnts); } -/** - * __qrwlock_write_byte - retrieve the write byte address of a queue rwlock - * @lock : Pointer to queue rwlock structure - * Return: the write byte address of a queue rwlock - */ -static inline u8 *__qrwlock_write_byte(struct qrwlock *lock) -{ - return (u8 *)lock + 3 * IS_BUILTIN(CONFIG_CPU_BIG_ENDIAN); -} - /** * queued_write_unlock - release write lock of a queue rwlock * @lock : Pointer to queue rwlock structure */ static inline void queued_write_unlock(struct qrwlock *lock) { - smp_store_release(__qrwlock_write_byte(lock), 0); + smp_store_release(&lock->wmode, 0); } /* diff --git a/include/asm-generic/qrwlock_types.h b/include/asm-generic/qrwlock_types.h index 0abc6b6062fb..507f2dc51bba 100644 --- a/include/asm-generic/qrwlock_types.h +++ b/include/asm-generic/qrwlock_types.h @@ -9,12 +9,23 @@ */ typedef struct qrwlock { - atomic_t cnts; + union { + atomic_t cnts; + struct { +#ifdef __LITTLE_ENDIAN + u8 wmode; /* Writer mode */ + u8 rcnts[3]; /* Reader counts */ +#else + u8 rcnts[3]; /* Reader counts */ + u8 wmode; /* Writer mode */ +#endif + }; + }; arch_spinlock_t wait_lock; } arch_rwlock_t; #define __ARCH_RW_LOCK_UNLOCKED { \ - .cnts = ATOMIC_INIT(0), \ + { .cnts = ATOMIC_INIT(0), }, \ .wait_lock = __ARCH_SPIN_LOCK_UNLOCKED, \ } diff --git a/kernel/locking/qrwlock.c b/kernel/locking/qrwlock.c index 2655f26ec882..1af791e37348 100644 --- a/kernel/locking/qrwlock.c +++ b/kernel/locking/qrwlock.c @@ -23,26 +23,6 @@ #include #include -/* - * This internal data structure is used for optimizing access to some of - * the subfields within the atomic_t cnts. - */ -struct __qrwlock { - union { - atomic_t cnts; - struct { -#ifdef __LITTLE_ENDIAN - u8 wmode; /* Writer mode */ - u8 rcnts[3]; /* Reader counts */ -#else - u8 rcnts[3]; /* Reader counts */ - u8 wmode; /* Writer mode */ -#endif - }; - }; - arch_spinlock_t lock; -}; - /** * rspin_until_writer_unlock - inc reader count & spin until writer is gone * @lock : Pointer to queue rwlock structure @@ -125,10 +105,8 @@ void queued_write_lock_slowpath(struct qrwlock *lock) * or wait for a previous writer to go away. */ for (;;) { - struct __qrwlock *l = (struct __qrwlock *)lock; - - if (!READ_ONCE(l->wmode) && - (cmpxchg_relaxed(&l->wmode, 0, _QW_WAITING) == 0)) + if (!READ_ONCE(lock->wmode) && + (cmpxchg_relaxed(&lock->wmode, 0, _QW_WAITING) == 0)) break; cpu_relax(); From 4df714be4dcf40bfb0d4af0f851a6e1977afa02e Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Thu, 12 Oct 2017 13:20:48 +0100 Subject: [PATCH 24/70] locking/atomic: Add atomic_cond_read_acquire() smp_cond_load_acquire() provides a way to spin on a variable with acquire semantics until some conditional expression involving the variable is satisfied. Architectures such as arm64 can potentially enter a low-power state, waking up only when the value of the variable changes, which reduces the system impact of tight polling loops. This patch makes the same interface available to users of atomic_t, atomic64_t and atomic_long_t, rather than require messy accesses to the structure internals. Signed-off-by: Will Deacon Acked-by: Peter Zijlstra Cc: Boqun Feng Cc: Jeremy.Linton@arm.com Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Thomas Gleixner Cc: Waiman Long Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1507810851-306-3-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar --- include/asm-generic/atomic-long.h | 3 +++ include/linux/atomic.h | 4 ++++ 2 files changed, 7 insertions(+) diff --git a/include/asm-generic/atomic-long.h b/include/asm-generic/atomic-long.h index 288cc9e96395..f2d97b782031 100644 --- a/include/asm-generic/atomic-long.h +++ b/include/asm-generic/atomic-long.h @@ -243,4 +243,7 @@ static inline long atomic_long_add_unless(atomic_long_t *l, long a, long u) #define atomic_long_inc_not_zero(l) \ ATOMIC_LONG_PFX(_inc_not_zero)((ATOMIC_LONG_PFX(_t) *)(l)) +#define atomic_long_cond_read_acquire(v, c) \ + ATOMIC_LONG_PFX(_cond_read_acquire)((ATOMIC_LONG_PFX(_t) *)(v), (c)) + #endif /* _ASM_GENERIC_ATOMIC_LONG_H */ diff --git a/include/linux/atomic.h b/include/linux/atomic.h index 40d6bfec0e0d..0aeb2b3f4578 100644 --- a/include/linux/atomic.h +++ b/include/linux/atomic.h @@ -653,6 +653,8 @@ static inline int atomic_dec_if_positive(atomic_t *v) } #endif +#define atomic_cond_read_acquire(v, c) smp_cond_load_acquire(&(v)->counter, (c)) + #ifdef CONFIG_GENERIC_ATOMIC64 #include #endif @@ -1072,6 +1074,8 @@ static inline long long atomic64_fetch_andnot_release(long long i, atomic64_t *v } #endif +#define atomic64_cond_read_acquire(v, c) smp_cond_load_acquire(&(v)->counter, (c)) + #include #endif /* _LINUX_ATOMIC_H */ From b519b56e378ee82caf9b079b04f5db87dedc3251 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Thu, 12 Oct 2017 13:20:49 +0100 Subject: [PATCH 25/70] locking/qrwlock: Use atomic_cond_read_acquire() when spinning in qrwlock The qrwlock slowpaths involve spinning when either a prospective reader is waiting for a concurrent writer to drain, or a prospective writer is waiting for concurrent readers to drain. In both of these situations, atomic_cond_read_acquire() can be used to avoid busy-waiting and make use of any backoff functionality provided by the architecture. This patch replaces the open-code loops and rspin_until_writer_unlock() implementation with atomic_cond_read_acquire(). The write mode transition zero to _QW_WAITING is left alone, since (a) this doesn't need acquire semantics and (b) should be fast. Tested-by: Waiman Long Tested-by: Jeremy Linton Tested-by: Adam Wallis Tested-by: Jan Glauber Signed-off-by: Will Deacon Acked-by: Peter Zijlstra Cc: Boqun Feng Cc: Jeremy.Linton@arm.com Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Thomas Gleixner Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1507810851-306-4-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar --- include/asm-generic/qrwlock.h | 4 +-- kernel/locking/qrwlock.c | 50 +++++++++-------------------------- 2 files changed, 14 insertions(+), 40 deletions(-) diff --git a/include/asm-generic/qrwlock.h b/include/asm-generic/qrwlock.h index 02c0a768e6b0..c716b02e8fd7 100644 --- a/include/asm-generic/qrwlock.h +++ b/include/asm-generic/qrwlock.h @@ -49,7 +49,7 @@ /* * External function declarations */ -extern void queued_read_lock_slowpath(struct qrwlock *lock, u32 cnts); +extern void queued_read_lock_slowpath(struct qrwlock *lock); extern void queued_write_lock_slowpath(struct qrwlock *lock); /** @@ -100,7 +100,7 @@ static inline void queued_read_lock(struct qrwlock *lock) return; /* The slowpath will decrement the reader count, if necessary. */ - queued_read_lock_slowpath(lock, cnts); + queued_read_lock_slowpath(lock); } /** diff --git a/kernel/locking/qrwlock.c b/kernel/locking/qrwlock.c index 1af791e37348..5825e0fc1a8e 100644 --- a/kernel/locking/qrwlock.c +++ b/kernel/locking/qrwlock.c @@ -23,29 +23,11 @@ #include #include -/** - * rspin_until_writer_unlock - inc reader count & spin until writer is gone - * @lock : Pointer to queue rwlock structure - * @writer: Current queue rwlock writer status byte - * - * In interrupt context or at the head of the queue, the reader will just - * increment the reader count & wait until the writer releases the lock. - */ -static __always_inline void -rspin_until_writer_unlock(struct qrwlock *lock, u32 cnts) -{ - while ((cnts & _QW_WMASK) == _QW_LOCKED) { - cpu_relax(); - cnts = atomic_read_acquire(&lock->cnts); - } -} - /** * queued_read_lock_slowpath - acquire read lock of a queue rwlock * @lock: Pointer to queue rwlock structure - * @cnts: Current qrwlock lock value */ -void queued_read_lock_slowpath(struct qrwlock *lock, u32 cnts) +void queued_read_lock_slowpath(struct qrwlock *lock) { /* * Readers come here when they cannot get the lock without waiting @@ -53,13 +35,12 @@ void queued_read_lock_slowpath(struct qrwlock *lock, u32 cnts) if (unlikely(in_interrupt())) { /* * Readers in interrupt context will get the lock immediately - * if the writer is just waiting (not holding the lock yet). - * The rspin_until_writer_unlock() function returns immediately - * in this case. Otherwise, they will spin (with ACQUIRE - * semantics) until the lock is available without waiting in - * the queue. + * if the writer is just waiting (not holding the lock yet), + * so spin with ACQUIRE semantics until the lock is available + * without waiting in the queue. */ - rspin_until_writer_unlock(lock, cnts); + atomic_cond_read_acquire(&lock->cnts, (VAL & _QW_WMASK) + != _QW_LOCKED); return; } atomic_sub(_QR_BIAS, &lock->cnts); @@ -68,14 +49,14 @@ void queued_read_lock_slowpath(struct qrwlock *lock, u32 cnts) * Put the reader into the wait queue */ arch_spin_lock(&lock->wait_lock); + atomic_add(_QR_BIAS, &lock->cnts); /* * The ACQUIRE semantics of the following spinning code ensure * that accesses can't leak upwards out of our subsequent critical * section in the case that the lock is currently held for write. */ - cnts = atomic_fetch_add_acquire(_QR_BIAS, &lock->cnts); - rspin_until_writer_unlock(lock, cnts); + atomic_cond_read_acquire(&lock->cnts, (VAL & _QW_WMASK) != _QW_LOCKED); /* * Signal the next one in queue to become queue head @@ -90,8 +71,6 @@ EXPORT_SYMBOL(queued_read_lock_slowpath); */ void queued_write_lock_slowpath(struct qrwlock *lock) { - u32 cnts; - /* Put the writer into the wait queue */ arch_spin_lock(&lock->wait_lock); @@ -113,15 +92,10 @@ void queued_write_lock_slowpath(struct qrwlock *lock) } /* When no more readers, set the locked flag */ - for (;;) { - cnts = atomic_read(&lock->cnts); - if ((cnts == _QW_WAITING) && - (atomic_cmpxchg_acquire(&lock->cnts, _QW_WAITING, - _QW_LOCKED) == _QW_WAITING)) - break; - - cpu_relax(); - } + do { + atomic_cond_read_acquire(&lock->cnts, VAL == _QW_WAITING); + } while (atomic_cmpxchg_relaxed(&lock->cnts, _QW_WAITING, + _QW_LOCKED) != _QW_WAITING); unlock: arch_spin_unlock(&lock->wait_lock); } From 087133ac90763cd339b6b67f2998f87dcc136c52 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Thu, 12 Oct 2017 13:20:50 +0100 Subject: [PATCH 26/70] locking/qrwlock, arm64: Move rwlock implementation over to qrwlocks Now that the qrwlock can make use of WFE, remove our homebrewed rwlock code in favour of the generic queued implementation. Tested-by: Waiman Long Tested-by: Jeremy Linton Tested-by: Adam Wallis Tested-by: Jan Glauber Signed-off-by: Will Deacon Acked-by: Peter Zijlstra Cc: Jeremy.Linton@arm.com Cc: Linus Torvalds Cc: Thomas Gleixner Cc: boqun.feng@gmail.com Cc: linux-arm-kernel@lists.infradead.org Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1507810851-306-5-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar --- arch/arm64/Kconfig | 17 +++ arch/arm64/include/asm/Kbuild | 1 + arch/arm64/include/asm/spinlock.h | 164 +----------------------- arch/arm64/include/asm/spinlock_types.h | 6 +- 4 files changed, 20 insertions(+), 168 deletions(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 0df64a6a56d4..df02ad932020 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -22,7 +22,24 @@ config ARM64 select ARCH_HAS_STRICT_MODULE_RWX select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST select ARCH_HAVE_NMI_SAFE_CMPXCHG if ACPI_APEI_SEA + select ARCH_INLINE_READ_LOCK if !PREEMPT + select ARCH_INLINE_READ_LOCK_BH if !PREEMPT + select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPT + select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPT + select ARCH_INLINE_READ_UNLOCK if !PREEMPT + select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPT + select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPT + select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPT + select ARCH_INLINE_WRITE_LOCK if !PREEMPT + select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPT + select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPT + select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPT + select ARCH_INLINE_WRITE_UNLOCK if !PREEMPT + select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPT + select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPT + select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPT select ARCH_USE_CMPXCHG_LOCKREF + select ARCH_USE_QUEUED_RWLOCKS select ARCH_SUPPORTS_MEMORY_FAILURE select ARCH_SUPPORTS_ATOMIC_RMW select ARCH_SUPPORTS_NUMA_BALANCING diff --git a/arch/arm64/include/asm/Kbuild b/arch/arm64/include/asm/Kbuild index 2326e39d5892..e63d0a8312de 100644 --- a/arch/arm64/include/asm/Kbuild +++ b/arch/arm64/include/asm/Kbuild @@ -16,6 +16,7 @@ generic-y += mcs_spinlock.h generic-y += mm-arch-hooks.h generic-y += msi.h generic-y += preempt.h +generic-y += qrwlock.h generic-y += rwsem.h generic-y += segment.h generic-y += serial.h diff --git a/arch/arm64/include/asm/spinlock.h b/arch/arm64/include/asm/spinlock.h index aa51a38e46e4..fdb827c7832f 100644 --- a/arch/arm64/include/asm/spinlock.h +++ b/arch/arm64/include/asm/spinlock.h @@ -137,169 +137,7 @@ static inline int arch_spin_is_contended(arch_spinlock_t *lock) } #define arch_spin_is_contended arch_spin_is_contended -/* - * Write lock implementation. - * - * Write locks set bit 31. Unlocking, is done by writing 0 since the lock is - * exclusively held. - * - * The memory barriers are implicit with the load-acquire and store-release - * instructions. - */ - -static inline void arch_write_lock(arch_rwlock_t *rw) -{ - unsigned int tmp; - - asm volatile(ARM64_LSE_ATOMIC_INSN( - /* LL/SC */ - " sevl\n" - "1: wfe\n" - "2: ldaxr %w0, %1\n" - " cbnz %w0, 1b\n" - " stxr %w0, %w2, %1\n" - " cbnz %w0, 2b\n" - __nops(1), - /* LSE atomics */ - "1: mov %w0, wzr\n" - "2: casa %w0, %w2, %1\n" - " cbz %w0, 3f\n" - " ldxr %w0, %1\n" - " cbz %w0, 2b\n" - " wfe\n" - " b 1b\n" - "3:") - : "=&r" (tmp), "+Q" (rw->lock) - : "r" (0x80000000) - : "memory"); -} - -static inline int arch_write_trylock(arch_rwlock_t *rw) -{ - unsigned int tmp; - - asm volatile(ARM64_LSE_ATOMIC_INSN( - /* LL/SC */ - "1: ldaxr %w0, %1\n" - " cbnz %w0, 2f\n" - " stxr %w0, %w2, %1\n" - " cbnz %w0, 1b\n" - "2:", - /* LSE atomics */ - " mov %w0, wzr\n" - " casa %w0, %w2, %1\n" - __nops(2)) - : "=&r" (tmp), "+Q" (rw->lock) - : "r" (0x80000000) - : "memory"); - - return !tmp; -} - -static inline void arch_write_unlock(arch_rwlock_t *rw) -{ - asm volatile(ARM64_LSE_ATOMIC_INSN( - " stlr wzr, %0", - " swpl wzr, wzr, %0") - : "=Q" (rw->lock) :: "memory"); -} - -/* write_can_lock - would write_trylock() succeed? */ -#define arch_write_can_lock(x) ((x)->lock == 0) - -/* - * Read lock implementation. - * - * It exclusively loads the lock value, increments it and stores the new value - * back if positive and the CPU still exclusively owns the location. If the - * value is negative, the lock is already held. - * - * During unlocking there may be multiple active read locks but no write lock. - * - * The memory barriers are implicit with the load-acquire and store-release - * instructions. - * - * Note that in UNDEFINED cases, such as unlocking a lock twice, the LL/SC - * and LSE implementations may exhibit different behaviour (although this - * will have no effect on lockdep). - */ -static inline void arch_read_lock(arch_rwlock_t *rw) -{ - unsigned int tmp, tmp2; - - asm volatile( - " sevl\n" - ARM64_LSE_ATOMIC_INSN( - /* LL/SC */ - "1: wfe\n" - "2: ldaxr %w0, %2\n" - " add %w0, %w0, #1\n" - " tbnz %w0, #31, 1b\n" - " stxr %w1, %w0, %2\n" - " cbnz %w1, 2b\n" - __nops(1), - /* LSE atomics */ - "1: wfe\n" - "2: ldxr %w0, %2\n" - " adds %w1, %w0, #1\n" - " tbnz %w1, #31, 1b\n" - " casa %w0, %w1, %2\n" - " sbc %w0, %w1, %w0\n" - " cbnz %w0, 2b") - : "=&r" (tmp), "=&r" (tmp2), "+Q" (rw->lock) - : - : "cc", "memory"); -} - -static inline void arch_read_unlock(arch_rwlock_t *rw) -{ - unsigned int tmp, tmp2; - - asm volatile(ARM64_LSE_ATOMIC_INSN( - /* LL/SC */ - "1: ldxr %w0, %2\n" - " sub %w0, %w0, #1\n" - " stlxr %w1, %w0, %2\n" - " cbnz %w1, 1b", - /* LSE atomics */ - " movn %w0, #0\n" - " staddl %w0, %2\n" - __nops(2)) - : "=&r" (tmp), "=&r" (tmp2), "+Q" (rw->lock) - : - : "memory"); -} - -static inline int arch_read_trylock(arch_rwlock_t *rw) -{ - unsigned int tmp, tmp2; - - asm volatile(ARM64_LSE_ATOMIC_INSN( - /* LL/SC */ - " mov %w1, #1\n" - "1: ldaxr %w0, %2\n" - " add %w0, %w0, #1\n" - " tbnz %w0, #31, 2f\n" - " stxr %w1, %w0, %2\n" - " cbnz %w1, 1b\n" - "2:", - /* LSE atomics */ - " ldr %w0, %2\n" - " adds %w1, %w0, #1\n" - " tbnz %w1, #31, 1f\n" - " casa %w0, %w1, %2\n" - " sbc %w1, %w1, %w0\n" - __nops(1) - "1:") - : "=&r" (tmp), "=&r" (tmp2), "+Q" (rw->lock) - : - : "cc", "memory"); - - return !tmp2; -} - -/* read_can_lock - would read_trylock() succeed? */ -#define arch_read_can_lock(x) ((x)->lock < 0x80000000) +#include /* See include/linux/spinlock.h */ #define smp_mb__after_spinlock() smp_mb() diff --git a/arch/arm64/include/asm/spinlock_types.h b/arch/arm64/include/asm/spinlock_types.h index 55be59a35e3f..6b856012c51b 100644 --- a/arch/arm64/include/asm/spinlock_types.h +++ b/arch/arm64/include/asm/spinlock_types.h @@ -36,10 +36,6 @@ typedef struct { #define __ARCH_SPIN_LOCK_UNLOCKED { 0 , 0 } -typedef struct { - volatile unsigned int lock; -} arch_rwlock_t; - -#define __ARCH_RW_LOCK_UNLOCKED { 0 } +#include #endif From d133166146333e1f13fc81c0e6c43c8d99290a8a Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Thu, 12 Oct 2017 13:20:51 +0100 Subject: [PATCH 27/70] locking/qrwlock: Prevent slowpath writers getting held up by fastpath When a prospective writer takes the qrwlock locking slowpath due to the lock being held, it attempts to cmpxchg the wmode field from 0 to _QW_WAITING so that concurrent lockers also take the slowpath and queue on the spinlock accordingly, allowing the lockers to drain. Unfortunately, this isn't fair, because a fastpath writer that comes in after the lock is made available but before the _QW_WAITING flag is set can effectively jump the queue. If there is a steady stream of prospective writers, then the waiter will be held off indefinitely. This patch restores fairness by separating _QW_WAITING and _QW_LOCKED into two distinct fields: _QW_LOCKED continues to occupy the bottom byte of the lockword so that it can be cleared unconditionally when unlocking, but _QW_WAITING now occupies what used to be the bottom bit of the reader count. This then forces the slow-path for concurrent lockers. Tested-by: Waiman Long Tested-by: Jeremy Linton Tested-by: Adam Wallis Tested-by: Jan Glauber Signed-off-by: Will Deacon Acked-by: Peter Zijlstra Cc: Boqun Feng Cc: Jeremy.Linton@arm.com Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Thomas Gleixner Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1507810851-306-6-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar --- include/asm-generic/qrwlock.h | 23 +++++------------------ include/asm-generic/qrwlock_types.h | 8 ++++---- kernel/locking/qrwlock.c | 20 +++++--------------- 3 files changed, 14 insertions(+), 37 deletions(-) diff --git a/include/asm-generic/qrwlock.h b/include/asm-generic/qrwlock.h index c716b02e8fd7..0f7062bd55e5 100644 --- a/include/asm-generic/qrwlock.h +++ b/include/asm-generic/qrwlock.h @@ -26,24 +26,11 @@ /* * Writer states & reader shift and bias. - * - * | +0 | +1 | +2 | +3 | - * ----+----+----+----+----+ - * LE | 78 | 56 | 34 | 12 | 0x12345678 - * ----+----+----+----+----+ - * | wr | rd | - * +----+----+----+----+ - * - * ----+----+----+----+----+ - * BE | 12 | 34 | 56 | 78 | 0x12345678 - * ----+----+----+----+----+ - * | rd | wr | - * +----+----+----+----+ */ -#define _QW_WAITING 1 /* A writer is waiting */ -#define _QW_LOCKED 0xff /* A writer holds the lock */ -#define _QW_WMASK 0xff /* Writer mask */ -#define _QR_SHIFT 8 /* Reader count shift */ +#define _QW_WAITING 0x100 /* A writer is waiting */ +#define _QW_LOCKED 0x0ff /* A writer holds the lock */ +#define _QW_WMASK 0x1ff /* Writer mask */ +#define _QR_SHIFT 9 /* Reader count shift */ #define _QR_BIAS (1U << _QR_SHIFT) /* @@ -134,7 +121,7 @@ static inline void queued_read_unlock(struct qrwlock *lock) */ static inline void queued_write_unlock(struct qrwlock *lock) { - smp_store_release(&lock->wmode, 0); + smp_store_release(&lock->wlocked, 0); } /* diff --git a/include/asm-generic/qrwlock_types.h b/include/asm-generic/qrwlock_types.h index 507f2dc51bba..8af752acbdc0 100644 --- a/include/asm-generic/qrwlock_types.h +++ b/include/asm-generic/qrwlock_types.h @@ -13,11 +13,11 @@ typedef struct qrwlock { atomic_t cnts; struct { #ifdef __LITTLE_ENDIAN - u8 wmode; /* Writer mode */ - u8 rcnts[3]; /* Reader counts */ + u8 wlocked; /* Locked for write? */ + u8 __lstate[3]; #else - u8 rcnts[3]; /* Reader counts */ - u8 wmode; /* Writer mode */ + u8 __lstate[3]; + u8 wlocked; /* Locked for write? */ #endif }; }; diff --git a/kernel/locking/qrwlock.c b/kernel/locking/qrwlock.c index 5825e0fc1a8e..c7471c3fb798 100644 --- a/kernel/locking/qrwlock.c +++ b/kernel/locking/qrwlock.c @@ -39,8 +39,7 @@ void queued_read_lock_slowpath(struct qrwlock *lock) * so spin with ACQUIRE semantics until the lock is available * without waiting in the queue. */ - atomic_cond_read_acquire(&lock->cnts, (VAL & _QW_WMASK) - != _QW_LOCKED); + atomic_cond_read_acquire(&lock->cnts, !(VAL & _QW_LOCKED)); return; } atomic_sub(_QR_BIAS, &lock->cnts); @@ -56,7 +55,7 @@ void queued_read_lock_slowpath(struct qrwlock *lock) * that accesses can't leak upwards out of our subsequent critical * section in the case that the lock is currently held for write. */ - atomic_cond_read_acquire(&lock->cnts, (VAL & _QW_WMASK) != _QW_LOCKED); + atomic_cond_read_acquire(&lock->cnts, !(VAL & _QW_LOCKED)); /* * Signal the next one in queue to become queue head @@ -79,19 +78,10 @@ void queued_write_lock_slowpath(struct qrwlock *lock) (atomic_cmpxchg_acquire(&lock->cnts, 0, _QW_LOCKED) == 0)) goto unlock; - /* - * Set the waiting flag to notify readers that a writer is pending, - * or wait for a previous writer to go away. - */ - for (;;) { - if (!READ_ONCE(lock->wmode) && - (cmpxchg_relaxed(&lock->wmode, 0, _QW_WAITING) == 0)) - break; + /* Set the waiting flag to notify readers that a writer is pending */ + atomic_add(_QW_WAITING, &lock->cnts); - cpu_relax(); - } - - /* When no more readers, set the locked flag */ + /* When no more readers or writers, set the locked flag */ do { atomic_cond_read_acquire(&lock->cnts, VAL == _QW_WAITING); } while (atomic_cmpxchg_relaxed(&lock->cnts, _QW_WAITING, From d3e632f07b6e637d3643081873867ecb6433b2ce Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 23 Oct 2017 14:07:11 -0700 Subject: [PATCH 28/70] locking/atomics, dm-integrity: Convert ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE() For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't currently harmful. However, for some features it is necessary to instrument reads and writes separately, which is not possible with ACCESS_ONCE(). This distinction is critical to correct operation. It's possible to transform the bulk of kernel code using the Coccinelle script below. However, this doesn't pick up some uses, including those in dm-integrity.c. As a preparatory step, this patch converts the driver to use {READ,WRITE}_ONCE() consistently. At the same time, this patch adds the missing include of necessary for the {READ,WRITE}_ONCE() definitions. ---- virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland Signed-off-by: Paul E. McKenney Cc: Linus Torvalds Cc: Mike Snitzer Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-1-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar --- drivers/md/dm-integrity.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c index 096fe9b66c50..8c5756e1df94 100644 --- a/drivers/md/dm-integrity.c +++ b/drivers/md/dm-integrity.c @@ -6,6 +6,7 @@ * This file is released under the GPL. */ +#include #include #include #include @@ -80,13 +81,13 @@ struct journal_entry { #define journal_entry_tag(ic, je) ((__u8 *)&(je)->last_bytes[(ic)->sectors_per_block]) #if BITS_PER_LONG == 64 -#define journal_entry_set_sector(je, x) do { smp_wmb(); ACCESS_ONCE((je)->u.sector) = cpu_to_le64(x); } while (0) +#define journal_entry_set_sector(je, x) do { smp_wmb(); WRITE_ONCE((je)->u.sector, cpu_to_le64(x)); } while (0) #define journal_entry_get_sector(je) le64_to_cpu((je)->u.sector) #elif defined(CONFIG_LBDAF) -#define journal_entry_set_sector(je, x) do { (je)->u.s.sector_lo = cpu_to_le32(x); smp_wmb(); ACCESS_ONCE((je)->u.s.sector_hi) = cpu_to_le32((x) >> 32); } while (0) +#define journal_entry_set_sector(je, x) do { (je)->u.s.sector_lo = cpu_to_le32(x); smp_wmb(); WRITE_ONCE((je)->u.s.sector_hi, cpu_to_le32((x) >> 32)); } while (0) #define journal_entry_get_sector(je) le64_to_cpu((je)->u.sector) #else -#define journal_entry_set_sector(je, x) do { (je)->u.s.sector_lo = cpu_to_le32(x); smp_wmb(); ACCESS_ONCE((je)->u.s.sector_hi) = cpu_to_le32(0); } while (0) +#define journal_entry_set_sector(je, x) do { (je)->u.s.sector_lo = cpu_to_le32(x); smp_wmb(); WRITE_ONCE((je)->u.s.sector_hi, cpu_to_le32(0)); } while (0) #define journal_entry_get_sector(je) le32_to_cpu((je)->u.s.sector_lo) #endif #define journal_entry_is_unused(je) ((je)->u.s.sector_hi == cpu_to_le32(-1)) @@ -320,7 +321,7 @@ static void dm_integrity_io_error(struct dm_integrity_c *ic, const char *msg, in static int dm_integrity_failed(struct dm_integrity_c *ic) { - return ACCESS_ONCE(ic->failed); + return READ_ONCE(ic->failed); } static commit_id_t dm_integrity_commit_id(struct dm_integrity_c *ic, unsigned i, @@ -1545,7 +1546,7 @@ static bool __journal_read_write(struct dm_integrity_io *dio, struct bio *bio, smp_mb(); if (unlikely(waitqueue_active(&ic->copy_to_journal_wait))) wake_up(&ic->copy_to_journal_wait); - if (ACCESS_ONCE(ic->free_sectors) <= ic->free_sectors_threshold) { + if (READ_ONCE(ic->free_sectors) <= ic->free_sectors_threshold) { queue_work(ic->commit_wq, &ic->commit_work); } else { schedule_autocommit(ic); @@ -1798,7 +1799,7 @@ static void integrity_commit(struct work_struct *w) ic->n_committed_sections += commit_sections; spin_unlock_irq(&ic->endio_wait.lock); - if (ACCESS_ONCE(ic->free_sectors) <= ic->free_sectors_threshold) + if (READ_ONCE(ic->free_sectors) <= ic->free_sectors_threshold) queue_work(ic->writer_wq, &ic->writer_work); release_flush_bios: @@ -1980,7 +1981,7 @@ static void integrity_writer(struct work_struct *w) unsigned prev_free_sectors; /* the following test is not needed, but it tests the replay code */ - if (ACCESS_ONCE(ic->suspending)) + if (READ_ONCE(ic->suspending)) return; spin_lock_irq(&ic->endio_wait.lock); From 332efa6374de75c622b782569b16bb50fd722cf5 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 23 Oct 2017 14:07:12 -0700 Subject: [PATCH 29/70] locking/atomics, EDAC/altera: Convert ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE() For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't currently harmful. However, for some features it is necessary to instrument reads and writes separately, which is not possible with ACCESS_ONCE(). This distinction is critical to correct operation. It's possible to transform the bulk of kernel code using the Coccinelle script below. However, this doesn't handle comments, leaving references to ACCESS_ONCE() instances which have been removed. As a preparatory step, this patch converts the Altera EDAC code and comments to use {READ,WRITE}_ONCE() consistently. ---- virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland Signed-off-by: Paul E. McKenney Acked-by: Thor Thayer Cc: Borislav Petkov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-2-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar --- drivers/edac/altera_edac.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/edac/altera_edac.c b/drivers/edac/altera_edac.c index 346c4987b284..11d6419788c2 100644 --- a/drivers/edac/altera_edac.c +++ b/drivers/edac/altera_edac.c @@ -175,11 +175,11 @@ static ssize_t altr_sdr_mc_err_inject_write(struct file *file, /* * To trigger the error, we need to read the data back * (the data was written with errors above). - * The ACCESS_ONCE macros and printk are used to prevent the + * The READ_ONCE macros and printk are used to prevent the * the compiler optimizing these reads out. */ - reg = ACCESS_ONCE(ptemp[0]); - read_reg = ACCESS_ONCE(ptemp[1]); + reg = READ_ONCE(ptemp[0]); + read_reg = READ_ONCE(ptemp[1]); /* Force Read */ rmb(); @@ -618,7 +618,7 @@ static ssize_t altr_edac_device_trig(struct file *file, for (i = 0; i < (priv->trig_alloc_sz / sizeof(*ptemp)); i++) { /* Read data so we're in the correct state */ rmb(); - if (ACCESS_ONCE(ptemp[i])) + if (READ_ONCE(ptemp[i])) result = -1; /* Toggle Error bit (it is latched), leave ECC enabled */ writel(error_mask, (drvdata->base + priv->set_err_ofst)); @@ -635,7 +635,7 @@ static ssize_t altr_edac_device_trig(struct file *file, /* Read out written data. ECC error caused here */ for (i = 0; i < ALTR_TRIGGER_READ_WRD_CNT; i++) - if (ACCESS_ONCE(ptemp[i]) != i) + if (READ_ONCE(ptemp[i]) != i) edac_printk(KERN_ERR, EDAC_DEVICE, "Read doesn't match written data\n"); From eeafcc5a5925d0819dad462eac1d42fda5fbe36f Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 23 Oct 2017 14:07:13 -0700 Subject: [PATCH 30/70] locking/atomics, firmware/ivc: Convert ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE() workqueue: kill off ACCESS_ONCE() For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't currently harmful. However, for some features it is necessary to instrument reads and writes separately, which is not possible with ACCESS_ONCE(). This distinction is critical to correct operation. It's possible to transform the bulk of kernel code using the Coccinelle script below. However, this doesn't handle comments, leaving references to ACCESS_ONCE() instances which have been removed. As a preparatory step, this patch converts the Tegra IVC code and comments to use {READ,WRITE}_ONCE() consistently. ---- virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland Signed-off-by: Paul E. McKenney Cc: Jonathan Hunter Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thierry Reding Cc: Thomas Gleixner Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-3-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar --- drivers/firmware/tegra/ivc.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) diff --git a/drivers/firmware/tegra/ivc.c b/drivers/firmware/tegra/ivc.c index a01461d63f68..00de793e6423 100644 --- a/drivers/firmware/tegra/ivc.c +++ b/drivers/firmware/tegra/ivc.c @@ -99,11 +99,11 @@ static inline bool tegra_ivc_empty(struct tegra_ivc *ivc, { /* * This function performs multiple checks on the same values with - * security implications, so create snapshots with ACCESS_ONCE() to + * security implications, so create snapshots with READ_ONCE() to * ensure that these checks use the same values. */ - u32 tx = ACCESS_ONCE(header->tx.count); - u32 rx = ACCESS_ONCE(header->rx.count); + u32 tx = READ_ONCE(header->tx.count); + u32 rx = READ_ONCE(header->rx.count); /* * Perform an over-full check to prevent denial of service attacks @@ -124,8 +124,8 @@ static inline bool tegra_ivc_empty(struct tegra_ivc *ivc, static inline bool tegra_ivc_full(struct tegra_ivc *ivc, struct tegra_ivc_header *header) { - u32 tx = ACCESS_ONCE(header->tx.count); - u32 rx = ACCESS_ONCE(header->rx.count); + u32 tx = READ_ONCE(header->tx.count); + u32 rx = READ_ONCE(header->rx.count); /* * Invalid cases where the counters indicate that the queue is over @@ -137,8 +137,8 @@ static inline bool tegra_ivc_full(struct tegra_ivc *ivc, static inline u32 tegra_ivc_available(struct tegra_ivc *ivc, struct tegra_ivc_header *header) { - u32 tx = ACCESS_ONCE(header->tx.count); - u32 rx = ACCESS_ONCE(header->rx.count); + u32 tx = READ_ONCE(header->tx.count); + u32 rx = READ_ONCE(header->rx.count); /* * This function isn't expected to be used in scenarios where an @@ -151,8 +151,8 @@ static inline u32 tegra_ivc_available(struct tegra_ivc *ivc, static inline void tegra_ivc_advance_tx(struct tegra_ivc *ivc) { - ACCESS_ONCE(ivc->tx.channel->tx.count) = - ACCESS_ONCE(ivc->tx.channel->tx.count) + 1; + WRITE_ONCE(ivc->tx.channel->tx.count, + READ_ONCE(ivc->tx.channel->tx.count) + 1); if (ivc->tx.position == ivc->num_frames - 1) ivc->tx.position = 0; @@ -162,8 +162,8 @@ static inline void tegra_ivc_advance_tx(struct tegra_ivc *ivc) static inline void tegra_ivc_advance_rx(struct tegra_ivc *ivc) { - ACCESS_ONCE(ivc->rx.channel->rx.count) = - ACCESS_ONCE(ivc->rx.channel->rx.count) + 1; + WRITE_ONCE(ivc->rx.channel->rx.count, + READ_ONCE(ivc->rx.channel->rx.count) + 1); if (ivc->rx.position == ivc->num_frames - 1) ivc->rx.position = 0; @@ -428,7 +428,7 @@ int tegra_ivc_notified(struct tegra_ivc *ivc) /* Copy the receiver's state out of shared memory. */ tegra_ivc_invalidate(ivc, ivc->rx.phys + offset); - state = ACCESS_ONCE(ivc->rx.channel->tx.state); + state = READ_ONCE(ivc->rx.channel->tx.state); if (state == TEGRA_IVC_STATE_SYNC) { offset = offsetof(struct tegra_ivc_header, tx.count); From 66702eb59064f1077e89cce8e7e3cd48ec4b486c Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 23 Oct 2017 14:07:14 -0700 Subject: [PATCH 31/70] locking/atomics, fs/dcache: Convert ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE() For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't currently harmful. However, for some features it is necessary to instrument reads and writes separately, which is not possible with ACCESS_ONCE(). This distinction is critical to correct operation. It's possible to transform the bulk of kernel code using the Coccinelle script below. However, this doesn't handle comments, leaving references to ACCESS_ONCE() instances which have been removed. As a preparatory step, this patch converts the dcache code and comments to use {READ,WRITE}_ONCE() consistently. ---- virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland Signed-off-by: Paul E. McKenney Cc: Al Viro Cc: Andrew Morton Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-4-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar --- fs/dcache.c | 18 +++++++++--------- include/linux/dcache.h | 4 ++-- 2 files changed, 11 insertions(+), 11 deletions(-) diff --git a/fs/dcache.c b/fs/dcache.c index 34c852af215c..bcc9f6981569 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -630,7 +630,7 @@ static inline struct dentry *lock_parent(struct dentry *dentry) rcu_read_lock(); spin_unlock(&dentry->d_lock); again: - parent = ACCESS_ONCE(dentry->d_parent); + parent = READ_ONCE(dentry->d_parent); spin_lock(&parent->d_lock); /* * We can't blindly lock dentry until we are sure @@ -721,7 +721,7 @@ static inline bool fast_dput(struct dentry *dentry) * around with a zero refcount. */ smp_rmb(); - d_flags = ACCESS_ONCE(dentry->d_flags); + d_flags = READ_ONCE(dentry->d_flags); d_flags &= DCACHE_REFERENCED | DCACHE_LRU_LIST | DCACHE_DISCONNECTED; /* Nothing to do? Dropping the reference was all we needed? */ @@ -850,11 +850,11 @@ struct dentry *dget_parent(struct dentry *dentry) * locking. */ rcu_read_lock(); - ret = ACCESS_ONCE(dentry->d_parent); + ret = READ_ONCE(dentry->d_parent); gotref = lockref_get_not_zero(&ret->d_lockref); rcu_read_unlock(); if (likely(gotref)) { - if (likely(ret == ACCESS_ONCE(dentry->d_parent))) + if (likely(ret == READ_ONCE(dentry->d_parent))) return ret; dput(ret); } @@ -3040,7 +3040,7 @@ static int prepend(char **buffer, int *buflen, const char *str, int namelen) * @buflen: allocated length of the buffer * @name: name string and length qstr structure * - * With RCU path tracing, it may race with d_move(). Use ACCESS_ONCE() to + * With RCU path tracing, it may race with d_move(). Use READ_ONCE() to * make sure that either the old or the new name pointer and length are * fetched. However, there may be mismatch between length and pointer. * The length cannot be trusted, we need to copy it byte-by-byte until @@ -3054,8 +3054,8 @@ static int prepend(char **buffer, int *buflen, const char *str, int namelen) */ static int prepend_name(char **buffer, int *buflen, const struct qstr *name) { - const char *dname = ACCESS_ONCE(name->name); - u32 dlen = ACCESS_ONCE(name->len); + const char *dname = READ_ONCE(name->name); + u32 dlen = READ_ONCE(name->len); char *p; smp_read_barrier_depends(); @@ -3120,7 +3120,7 @@ static int prepend_path(const struct path *path, struct dentry * parent; if (dentry == vfsmnt->mnt_root || IS_ROOT(dentry)) { - struct mount *parent = ACCESS_ONCE(mnt->mnt_parent); + struct mount *parent = READ_ONCE(mnt->mnt_parent); /* Escaped? */ if (dentry != vfsmnt->mnt_root) { bptr = *buffer; @@ -3130,7 +3130,7 @@ static int prepend_path(const struct path *path, } /* Global root? */ if (mnt != parent) { - dentry = ACCESS_ONCE(mnt->mnt_mountpoint); + dentry = READ_ONCE(mnt->mnt_mountpoint); mnt = parent; vfsmnt = &mnt->mnt; continue; diff --git a/include/linux/dcache.h b/include/linux/dcache.h index ed1a7cf6923a..1d8f5818f647 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -519,7 +519,7 @@ static inline struct inode *d_inode(const struct dentry *dentry) } /** - * d_inode_rcu - Get the actual inode of this dentry with ACCESS_ONCE() + * d_inode_rcu - Get the actual inode of this dentry with READ_ONCE() * @dentry: The dentry to query * * This is the helper normal filesystems should use to get at their own inodes @@ -527,7 +527,7 @@ static inline struct inode *d_inode(const struct dentry *dentry) */ static inline struct inode *d_inode_rcu(const struct dentry *dentry) { - return ACCESS_ONCE(dentry->d_inode); + return READ_ONCE(dentry->d_inode); } /** From fd7048adb7a5f3c44154675e0e128fe0f2e16bef Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 23 Oct 2017 14:07:15 -0700 Subject: [PATCH 32/70] locking/atomics, fs/ncpfs: Convert ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE() The NCPFS code has some stale comments regarding ACCESS_ONCE() uses which were removed a long time ago. Let's remove the stale comments. Signed-off-by: Mark Rutland Signed-off-by: Paul E. McKenney Cc: Alexander Viro Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Petr Vandrovec Cc: Thomas Gleixner Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-5-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar --- fs/ncpfs/dir.c | 9 --------- 1 file changed, 9 deletions(-) diff --git a/fs/ncpfs/dir.c b/fs/ncpfs/dir.c index 088f52484d6e..72cfaa253a8f 100644 --- a/fs/ncpfs/dir.c +++ b/fs/ncpfs/dir.c @@ -119,10 +119,6 @@ static inline int ncp_case_sensitive(const struct inode *i) /* * Note: leave the hash unchanged if the directory * is case-sensitive. - * - * Accessing the parent inode can be racy under RCU pathwalking. - * Use ACCESS_ONCE() to make sure we use _one_ particular inode, - * the callers will handle races. */ static int ncp_hash_dentry(const struct dentry *dentry, struct qstr *this) @@ -147,11 +143,6 @@ ncp_hash_dentry(const struct dentry *dentry, struct qstr *this) return 0; } -/* - * Accessing the parent inode can be racy under RCU pathwalking. - * Use ACCESS_ONCE() to make sure we use _one_ particular inode, - * the callers will handle races. - */ static int ncp_compare_dentry(const struct dentry *dentry, unsigned int len, const char *str, const struct qstr *name) From 24fbd6e04e4e4793ec9dd9c2e007b0b38d2ec3ab Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 23 Oct 2017 14:07:16 -0700 Subject: [PATCH 33/70] locking/atomics, media/dvb_ringbuffer: Convert ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE() For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't currently harmful. However, for some features it is necessary to instrument reads and writes separately, which is not possible with ACCESS_ONCE(). This distinction is critical to correct operation. It's possible to transform the bulk of kernel code using the Coccinelle script below. However, this doesn't handle comments, leaving references to ACCESS_ONCE() instances which have been removed. As a preparatory step, this patch converts the DVB ringbuffer code and comments to use {READ,WRITE}_ONCE() consistently. ---- virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland Signed-off-by: Paul E. McKenney Cc: Linus Torvalds Cc: Mauro Carvalho Chehab Cc: Peter Zijlstra Cc: Sakari Ailus Cc: Thomas Gleixner Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-6-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar --- drivers/media/dvb-core/dvb_ringbuffer.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/media/dvb-core/dvb_ringbuffer.c b/drivers/media/dvb-core/dvb_ringbuffer.c index 2322af1b8742..53011629c9ad 100644 --- a/drivers/media/dvb-core/dvb_ringbuffer.c +++ b/drivers/media/dvb-core/dvb_ringbuffer.c @@ -66,12 +66,12 @@ ssize_t dvb_ringbuffer_free(struct dvb_ringbuffer *rbuf) { ssize_t free; - /* ACCESS_ONCE() to load read pointer on writer side + /* READ_ONCE() to load read pointer on writer side * this pairs with smp_store_release() in dvb_ringbuffer_read(), * dvb_ringbuffer_read_user(), dvb_ringbuffer_flush(), * or dvb_ringbuffer_reset() */ - free = ACCESS_ONCE(rbuf->pread) - rbuf->pwrite; + free = READ_ONCE(rbuf->pread) - rbuf->pwrite; if (free <= 0) free += rbuf->size; return free-1; @@ -143,7 +143,7 @@ ssize_t dvb_ringbuffer_read_user(struct dvb_ringbuffer *rbuf, u8 __user *buf, si todo -= split; /* smp_store_release() for read pointer update to ensure * that buf is not overwritten until read is complete, - * this pairs with ACCESS_ONCE() in dvb_ringbuffer_free() + * this pairs with READ_ONCE() in dvb_ringbuffer_free() */ smp_store_release(&rbuf->pread, 0); } @@ -168,7 +168,7 @@ void dvb_ringbuffer_read(struct dvb_ringbuffer *rbuf, u8 *buf, size_t len) todo -= split; /* smp_store_release() for read pointer update to ensure * that buf is not overwritten until read is complete, - * this pairs with ACCESS_ONCE() in dvb_ringbuffer_free() + * this pairs with READ_ONCE() in dvb_ringbuffer_free() */ smp_store_release(&rbuf->pread, 0); } From 14cd5d4a0125f643350e7fa12f5384f1fc2d3e9d Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 23 Oct 2017 14:07:17 -0700 Subject: [PATCH 34/70] locking/atomics, net/netlink/netfilter: Convert ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE() For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't currently harmful. However, for some features it is necessary to instrument reads and writes separately, which is not possible with ACCESS_ONCE(). This distinction is critical to correct operation. It's possible to transform the bulk of kernel code using the Coccinelle script below. However, this doesn't handle comments, leaving references to ACCESS_ONCE() instances which have been removed. As a preparatory step, this patch converts netlink and netfilter code and comments to use {READ,WRITE}_ONCE() consistently. ---- virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland Signed-off-by: Paul E. McKenney Cc: David S. Miller Cc: Florian Westphal Cc: Jozsef Kadlecsik Cc: Linus Torvalds Cc: Pablo Neira Ayuso Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-7-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar --- include/linux/genetlink.h | 2 +- include/linux/netfilter/nfnetlink.h | 2 +- include/linux/rtnetlink.h | 2 +- include/net/netfilter/nf_tables.h | 4 ++-- net/netfilter/ipvs/ip_vs_sync.c | 2 +- net/netfilter/nfnetlink_queue.c | 4 ++-- 6 files changed, 8 insertions(+), 8 deletions(-) diff --git a/include/linux/genetlink.h b/include/linux/genetlink.h index a4c61cbce777..0e694cf62414 100644 --- a/include/linux/genetlink.h +++ b/include/linux/genetlink.h @@ -30,7 +30,7 @@ extern wait_queue_head_t genl_sk_destructing_waitq; * @p: The pointer to read, prior to dereferencing * * Return the value of the specified RCU-protected pointer, but omit - * both the smp_read_barrier_depends() and the ACCESS_ONCE(), because + * both the smp_read_barrier_depends() and the READ_ONCE(), because * caller holds genl mutex. */ #define genl_dereference(p) \ diff --git a/include/linux/netfilter/nfnetlink.h b/include/linux/netfilter/nfnetlink.h index 41d04e9d088a..0f47a4aa7fc4 100644 --- a/include/linux/netfilter/nfnetlink.h +++ b/include/linux/netfilter/nfnetlink.h @@ -66,7 +66,7 @@ static inline bool lockdep_nfnl_is_held(__u8 subsys_id) * @ss: The nfnetlink subsystem ID * * Return the value of the specified RCU-protected pointer, but omit - * both the smp_read_barrier_depends() and the ACCESS_ONCE(), because + * both the smp_read_barrier_depends() and the READ_ONCE(), because * caller holds the NFNL subsystem mutex. */ #define nfnl_dereference(p, ss) \ diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h index dea59c8eec54..765f7b915475 100644 --- a/include/linux/rtnetlink.h +++ b/include/linux/rtnetlink.h @@ -67,7 +67,7 @@ static inline bool lockdep_rtnl_is_held(void) * @p: The pointer to read, prior to dereferencing * * Return the value of the specified RCU-protected pointer, but omit - * both the smp_read_barrier_depends() and the ACCESS_ONCE(), because + * both the smp_read_barrier_depends() and the READ_ONCE(), because * caller holds RTNL. */ #define rtnl_dereference(p) \ diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index 0f5b12a4ad09..5c68e279eaea 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -1164,8 +1164,8 @@ static inline u8 nft_genmask_next(const struct net *net) static inline u8 nft_genmask_cur(const struct net *net) { - /* Use ACCESS_ONCE() to prevent refetching the value for atomicity */ - return 1 << ACCESS_ONCE(net->nft.gencursor); + /* Use READ_ONCE() to prevent refetching the value for atomicity */ + return 1 << READ_ONCE(net->nft.gencursor); } #define NFT_GENMASK_ANY ((1 << 0) | (1 << 1)) diff --git a/net/netfilter/ipvs/ip_vs_sync.c b/net/netfilter/ipvs/ip_vs_sync.c index 0e5b64a75da0..1cfffd42d1e2 100644 --- a/net/netfilter/ipvs/ip_vs_sync.c +++ b/net/netfilter/ipvs/ip_vs_sync.c @@ -457,7 +457,7 @@ static inline bool in_persistence(struct ip_vs_conn *cp) static int ip_vs_sync_conn_needed(struct netns_ipvs *ipvs, struct ip_vs_conn *cp, int pkts) { - unsigned long orig = ACCESS_ONCE(cp->sync_endtime); + unsigned long orig = READ_ONCE(cp->sync_endtime); unsigned long now = jiffies; unsigned long n = (now + cp->timeout) & ~3UL; unsigned int sync_refresh_period; diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c index c9796629858f..a16356cacec3 100644 --- a/net/netfilter/nfnetlink_queue.c +++ b/net/netfilter/nfnetlink_queue.c @@ -401,7 +401,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, outdev = entry->state.out; - switch ((enum nfqnl_config_mode)ACCESS_ONCE(queue->copy_mode)) { + switch ((enum nfqnl_config_mode)READ_ONCE(queue->copy_mode)) { case NFQNL_COPY_META: case NFQNL_COPY_NONE: break; @@ -412,7 +412,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, skb_checksum_help(entskb)) return NULL; - data_len = ACCESS_ONCE(queue->copy_range); + data_len = READ_ONCE(queue->copy_range); if (data_len > entskb->len) data_len = entskb->len; From a9da6f29baf6b61fc94f9768638ee54e9bff173c Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 23 Oct 2017 14:07:18 -0700 Subject: [PATCH 35/70] locking/atomics, net/ipv4/tcp_input.c: Convert ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE() For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't currently harmful. However, for some features it is necessary to instrument reads and writes separately, which is not possible with ACCESS_ONCE(). This distinction is critical to correct operation. It's possible to transform the bulk of kernel code using the Coccinelle script below. However, this doesn't handle comments, leaving references to ACCESS_ONCE() instances which have been removed. As a preparatory step, this patch converts the IPv4 TCP input code and comments to use {READ,WRITE}_ONCE() consistently. ---- virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland Signed-off-by: Paul E. McKenney Cc: David S. Miller Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-8-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar --- net/ipv4/tcp_input.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 7eec3383702b..74480e039005 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -815,12 +815,12 @@ static void tcp_update_pacing_rate(struct sock *sk) if (likely(tp->srtt_us)) do_div(rate, tp->srtt_us); - /* ACCESS_ONCE() is needed because sch_fq fetches sk_pacing_rate + /* WRITE_ONCE() is needed because sch_fq fetches sk_pacing_rate * without any lock. We want to make sure compiler wont store * intermediate values in this location. */ - ACCESS_ONCE(sk->sk_pacing_rate) = min_t(u64, rate, - sk->sk_max_pacing_rate); + WRITE_ONCE(sk->sk_pacing_rate, min_t(u64, rate, + sk->sk_max_pacing_rate)); } /* Calculate rto without backoff. This is the second half of Van Jacobson's From ef4d9af62f47e3070b00c3307a4d8eb5092bb9a2 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 23 Oct 2017 14:07:19 -0700 Subject: [PATCH 36/70] locking/atomics, net/average: Convert ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE() For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't currently harmful. However, for some features it is necessary to instrument reads and writes separately, which is not possible with ACCESS_ONCE(). This distinction is critical to correct operation. It's possible to transform the bulk of kernel code using the Coccinelle script below. However, this doesn't pick up some uses, including those in . As a preparatory step, this patch converts the file to use {READ,WRITE}_ONCE() consistently. At the same time, this patch addds missing includes necessary for {READ,WRITE}_ONCE(), *BUG_ON*(), and ilog2(). ---- virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland Signed-off-by: Paul E. McKenney Reviewed-by: Johannes Berg Cc: David S. Miller Cc: Johannes Berg Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-9-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar --- include/linux/average.h | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/include/linux/average.h b/include/linux/average.h index 7ddaf340d2ac..3f462292269c 100644 --- a/include/linux/average.h +++ b/include/linux/average.h @@ -1,6 +1,10 @@ #ifndef _LINUX_AVERAGE_H #define _LINUX_AVERAGE_H +#include +#include +#include + /* * Exponentially weighted moving average (EWMA) * @@ -48,7 +52,7 @@ static inline void ewma_##name##_add(struct ewma_##name *e, \ unsigned long val) \ { \ - unsigned long internal = ACCESS_ONCE(e->internal); \ + unsigned long internal = READ_ONCE(e->internal); \ unsigned long weight_rcp = ilog2(_weight_rcp); \ unsigned long precision = _precision; \ \ @@ -57,10 +61,10 @@ BUILD_BUG_ON((_precision) > 30); \ BUILD_BUG_ON_NOT_POWER_OF_2(_weight_rcp); \ \ - ACCESS_ONCE(e->internal) = internal ? \ + WRITE_ONCE(e->internal, internal ? \ (((internal << weight_rcp) - internal) + \ (val << precision)) >> weight_rcp : \ - (val << precision); \ + (val << precision)); \ } #endif /* _LINUX_AVERAGE_H */ From 94bbc9c1a0b0967509f8ad91323245aad30572f7 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 23 Oct 2017 14:07:20 -0700 Subject: [PATCH 37/70] locking/atomics, samples/mic/mpssd/mpssd.c: Convert ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE() For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't currently harmful. However, for some features it is necessary to instrument reads and writes separately, which is not possible with ACCESS_ONCE(). This distinction is critical to correct operation. The bulk of the kernel code can be transformed via Coccinelle to use {READ,WRITE}_ONCE(), though this only modifies users of ACCESS_ONCE(), and not the implementation itself. As such, it has the potential to break homebrew ACCESS_ONCE() macros seen in some user code in the kernel tree (e.g. the virtio code, as fixed in commit ea9156fb3b71d9f7). To avoid fragility if/when that transformation occurs, and to align with the preferred usage of {READ,WRITE}_ONCE(), this patch updates the MPSSD sample code to use READ_ONCE() rather than ACCESS_ONCE(). There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland Signed-off-by: Paul E. McKenney Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Shuah Khan Cc: Thomas Gleixner Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-10-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar --- samples/mic/mpssd/mpssd.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/samples/mic/mpssd/mpssd.c b/samples/mic/mpssd/mpssd.c index 49db1def1721..f42ce551bb48 100644 --- a/samples/mic/mpssd/mpssd.c +++ b/samples/mic/mpssd/mpssd.c @@ -65,7 +65,7 @@ static struct mic_info mic_list; /* to align the pointer to the (next) page boundary */ #define PAGE_ALIGN(addr) _ALIGN(addr, PAGE_SIZE) -#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x)) +#define READ_ONCE(x) (*(volatile typeof(x) *)&(x)) #define GSO_ENABLED 1 #define MAX_GSO_SIZE (64 * 1024) @@ -382,7 +382,7 @@ disp_iovec(struct mic_info *mic, struct mic_copy_desc *copy, static inline __u16 read_avail_idx(struct mic_vring *vr) { - return ACCESS_ONCE(vr->info->avail_idx); + return READ_ONCE(vr->info->avail_idx); } static inline void txrx_prepare(int type, bool tx, struct mic_vring *vr, @@ -523,7 +523,7 @@ spin_for_descriptors(struct mic_info *mic, struct mic_vring *vr) { __u16 avail_idx = read_avail_idx(vr); - while (avail_idx == le16toh(ACCESS_ONCE(vr->vr.avail->idx))) { + while (avail_idx == le16toh(READ_ONCE(vr->vr.avail->idx))) { #ifdef DEBUG mpsslog("%s %s waiting for desc avail %d info_avail %d\n", mic->name, __func__, From 564cbc87937d5de1b5b666b0ed68122d6c74fa07 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 23 Oct 2017 14:07:21 -0700 Subject: [PATCH 38/70] locking/atomics, selftests/powerpc: Convert ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE() For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't currently harmful. However, for some features it is necessary to instrument reads and writes separately, which is not possible with ACCESS_ONCE(). This distinction is critical to correct operation. The bulk of the kernel code can be transformed via Coccinelle to use {READ,WRITE}_ONCE(), though this only modifies users of ACCESS_ONCE(), and not the implementation itself. As such, it has the potential to break homebrew ACCESS_ONCE() macros seen in some user code in the kernel tree (e.g. the virtio code, as fixed in commit ea9156fb3b71d9f7). To avoid fragility if/when that transformation occurs, and to align with the preferred usage of {READ,WRITE}_ONCE(), this patch updates the DSCR selftest code to use READ_ONCE() rather than ACCESS_ONCE(). There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland Signed-off-by: Paul E. McKenney Acked-by: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Linus Torvalds Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Shuah Khan Cc: Thomas Gleixner Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-11-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar --- tools/testing/selftests/powerpc/dscr/dscr.h | 2 +- tools/testing/selftests/powerpc/dscr/dscr_default_test.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/powerpc/dscr/dscr.h b/tools/testing/selftests/powerpc/dscr/dscr.h index 18ea223bd398..cdb840bc54f2 100644 --- a/tools/testing/selftests/powerpc/dscr/dscr.h +++ b/tools/testing/selftests/powerpc/dscr/dscr.h @@ -39,7 +39,7 @@ #define rmb() asm volatile("lwsync":::"memory") #define wmb() asm volatile("lwsync":::"memory") -#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x)) +#define READ_ONCE(x) (*(volatile typeof(x) *)&(x)) /* Prilvilege state DSCR access */ inline unsigned long get_dscr(void) diff --git a/tools/testing/selftests/powerpc/dscr/dscr_default_test.c b/tools/testing/selftests/powerpc/dscr/dscr_default_test.c index df17c3bab0a7..9e1a37e93b63 100644 --- a/tools/testing/selftests/powerpc/dscr/dscr_default_test.c +++ b/tools/testing/selftests/powerpc/dscr/dscr_default_test.c @@ -27,7 +27,7 @@ static void *do_test(void *in) unsigned long d, cur_dscr, cur_dscr_usr; unsigned long s1, s2; - s1 = ACCESS_ONCE(sequence); + s1 = READ_ONCE(sequence); if (s1 & 1) continue; rmb(); From c95491ed6d6a958743d82bea1d053819988da418 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 23 Oct 2017 14:07:22 -0700 Subject: [PATCH 39/70] locking/atomics, workqueue: Convert ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE() For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't currently harmful. However, for some features it is necessary to instrument reads and writes separately, which is not possible with ACCESS_ONCE(). This distinction is critical to correct operation. It's possible to transform the bulk of kernel code using the Coccinelle script below. However, this doesn't handle comments, leaving references to ACCESS_ONCE() instances which have been removed. As a preparatory step, this patch converts the workqueue code and comments to use {READ,WRITE}_ONCE() consistently. ---- virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland Signed-off-by: Paul E. McKenney Acked-by: Tejun Heo Cc: Lai Jiangshan Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-12-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar --- kernel/workqueue.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 64d0edf428f8..39831b2f3c5f 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -4647,7 +4647,7 @@ static void rebind_workers(struct worker_pool *pool) * concurrency management. Note that when or whether * @worker clears REBOUND doesn't affect correctness. * - * ACCESS_ONCE() is necessary because @worker->flags may be + * WRITE_ONCE() is necessary because @worker->flags may be * tested without holding any lock in * wq_worker_waking_up(). Without it, NOT_RUNNING test may * fail incorrectly leading to premature concurrency @@ -4656,7 +4656,7 @@ static void rebind_workers(struct worker_pool *pool) WARN_ON_ONCE(!(worker_flags & WORKER_UNBOUND)); worker_flags |= WORKER_REBOUND; worker_flags &= ~WORKER_UNBOUND; - ACCESS_ONCE(worker->flags) = worker_flags; + WRITE_ONCE(worker->flags, worker_flags); } spin_unlock_irq(&pool->lock); From 5cd38016d0c88e3f67528c1a7380a6d5c90859e9 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 23 Oct 2017 14:07:23 -0700 Subject: [PATCH 40/70] locking/atomics, rcutorture/formal: Prepare for ACCESS_ONCE() removal For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't currently harmful. However, for some features it is necessary to instrument reads and writes separately, which is not possible with ACCESS_ONCE(). This distinction is critical to correct operation. The bulk of the kernel code can be transformed via Coccinelle to use {READ,WRITE}_ONCE(), though this only modifies users of ACCESS_ONCE(), and not the implementation itself. As such, it has the potential to break homebrew ACCESS_ONCE() macros seen in some user code in the kernel tree (e.g. the virtio code, as fixed in commit ea9156fb3b71d9f7). To avoid fragility if/when that transformation occurs, this patch reworks the definitions of {READ,WRITE}_ONCE() in the rcutorture formal tests, and removes the unused ACCESS_ONCE() helper. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland Signed-off-by: Paul E. McKenney Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-13-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar --- .../selftests/rcutorture/formal/srcu-cbmc/src/barriers.h | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/barriers.h b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/barriers.h index 6687acc08e6d..cc27b9ebcf20 100644 --- a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/barriers.h +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/barriers.h @@ -34,8 +34,7 @@ #define rs_smp_mb() do {} while (0) #endif -#define ACCESS_ONCE(x) (*(volatile typeof(x) *) &(x)) -#define READ_ONCE(x) ACCESS_ONCE(x) -#define WRITE_ONCE(x, val) (ACCESS_ONCE(x) = (val)) +#define READ_ONCE(x) (*(volatile typeof(x) *) &(x)) +#define WRITE_ONCE(x) ((*(volatile typeof(x) *) &(x)) = (val)) #endif From 3587679d93d0b0e4c31e5a2ad1dffdfcb77e8526 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 23 Oct 2017 14:07:24 -0700 Subject: [PATCH 41/70] locking/atomics, doc/filesystems: Convert ACCESS_ONCE() references For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't currently harmful. However, for some features it is necessary to instrument reads and writes separately, which is not possible with ACCESS_ONCE(). This distinction is critical to correct operation. It's possible to transform the bulk of kernel code using the Coccinelle script below. However, this doesn't handle documentation, leaving references to ACCESS_ONCE() instances which have been removed. As a preparatory step, this patch converts the filesystems documentation to use {READ,WRITE}_ONCE() consistently. ---- virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Paul E. McKenney Acked-by: Will Deacon Acked-by: Mark Rutland Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Link: http://lkml.kernel.org/r/1508792849-3115-14-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar --- Documentation/filesystems/path-lookup.md | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/Documentation/filesystems/path-lookup.md b/Documentation/filesystems/path-lookup.md index 1b39e084a2b2..1933ef734e63 100644 --- a/Documentation/filesystems/path-lookup.md +++ b/Documentation/filesystems/path-lookup.md @@ -826,9 +826,9 @@ If the filesystem may need to revalidate dcache entries, then *is* passed the dentry but does not have access to the `inode` or the `seq` number from the `nameidata`, so it needs to be extra careful when accessing fields in the dentry. This "extra care" typically -involves using `ACCESS_ONCE()` or the newer [`READ_ONCE()`] to access -fields, and verifying the result is not NULL before using it. This -pattern can be see in `nfs_lookup_revalidate()`. +involves using [`READ_ONCE()`] to access fields, and verifying the +result is not NULL before using it. This pattern can be seen in +`nfs_lookup_revalidate()`. A pair of patterns ------------------ From b03a0fe0c5e4b46dcd400d27395b124499554a71 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 23 Oct 2017 14:07:25 -0700 Subject: [PATCH 42/70] locking/atomics, mm: Convert ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE() For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't currently harmful. However, for some features it is necessary to instrument reads and writes separately, which is not possible with ACCESS_ONCE(). This distinction is critical to correct operation. It's possible to transform the bulk of kernel code using the Coccinelle script below. However, this doesn't handle comments, leaving references to ACCESS_ONCE() instances which have been removed. As a preparatory step, this patch converts the mm code and comments to use {READ,WRITE}_ONCE() consistently. ---- virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Paul E. McKenney Acked-by: Will Deacon Acked-by: Mark Rutland Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Link: http://lkml.kernel.org/r/1508792849-3115-15-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar --- mm/memory.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index a728bed16c20..cae514e7dcfc 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3891,9 +3891,9 @@ static int handle_pte_fault(struct vm_fault *vmf) /* * some architectures can have larger ptes than wordsize, * e.g.ppc44x-defconfig has CONFIG_PTE_64BIT=y and - * CONFIG_32BIT=y, so READ_ONCE or ACCESS_ONCE cannot guarantee - * atomic accesses. The code below just needs a consistent - * view for the ifs and we later double check anyway with the + * CONFIG_32BIT=y, so READ_ONCE cannot guarantee atomic + * accesses. The code below just needs a consistent view + * for the ifs and we later double check anyway with the * ptl lock held. So here a barrier will do. */ barrier(); From 6aa7de059173a986114ac43b8f50b297a86f09a8 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 23 Oct 2017 14:07:29 -0700 Subject: [PATCH 43/70] locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE() Please do not apply this to mainline directly, instead please re-run the coccinelle script shown below and apply its output. For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't harmful, and changing them results in churn. However, for some features, the read/write distinction is critical to correct operation. To distinguish these cases, separate read/write accessors must be used. This patch migrates (most) remaining ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following coccinelle script: ---- // Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and // WRITE_ONCE() // $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland Signed-off-by: Paul E. McKenney Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar --- arch/arc/kernel/smp.c | 2 +- arch/arm/include/asm/spinlock.h | 2 +- arch/arm/mach-tegra/cpuidle-tegra20.c | 2 +- arch/arm/vdso/vgettimeofday.c | 2 +- arch/ia64/include/asm/spinlock.h | 8 ++--- arch/mips/include/asm/vdso.h | 2 +- arch/mips/kernel/pm-cps.c | 2 +- arch/mn10300/kernel/mn10300-serial.c | 4 +-- arch/parisc/include/asm/atomic.h | 2 +- arch/powerpc/platforms/powernv/opal-msglog.c | 2 +- arch/s390/include/asm/spinlock.h | 6 ++-- arch/s390/lib/spinlock.c | 16 ++++----- arch/sparc/include/asm/atomic_32.h | 2 +- arch/tile/gxio/dma_queue.c | 4 +-- arch/tile/include/gxio/dma_queue.h | 2 +- arch/tile/kernel/ptrace.c | 2 +- arch/x86/entry/common.c | 2 +- arch/x86/entry/vdso/vclock_gettime.c | 2 +- arch/x86/events/core.c | 2 +- arch/x86/include/asm/vgtod.h | 2 +- arch/x86/kernel/espfix_64.c | 6 ++-- arch/x86/kernel/nmi.c | 2 +- arch/x86/kvm/mmu.c | 4 +-- arch/x86/kvm/page_track.c | 2 +- arch/x86/xen/p2m.c | 2 +- arch/xtensa/platforms/xtfpga/lcd.c | 14 ++++---- block/blk-wbt.c | 2 +- drivers/base/core.c | 2 +- drivers/base/power/runtime.c | 4 +-- drivers/char/random.c | 4 +-- drivers/clocksource/bcm2835_timer.c | 2 +- drivers/crypto/caam/jr.c | 4 +-- drivers/crypto/nx/nx-842-powernv.c | 2 +- drivers/firewire/ohci.c | 10 +++--- drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c | 4 +-- drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 4 +-- drivers/gpu/drm/amd/scheduler/gpu_scheduler.c | 2 +- drivers/gpu/drm/radeon/radeon_gem.c | 4 +-- drivers/gpu/drm/vmwgfx/vmwgfx_surface.c | 2 +- drivers/infiniband/hw/hfi1/file_ops.c | 2 +- drivers/infiniband/hw/hfi1/pio.c | 6 ++-- drivers/infiniband/hw/hfi1/ruc.c | 2 +- drivers/infiniband/hw/hfi1/sdma.c | 8 ++--- drivers/infiniband/hw/hfi1/sdma.h | 2 +- drivers/infiniband/hw/hfi1/uc.c | 4 +-- drivers/infiniband/hw/hfi1/ud.c | 4 +-- drivers/infiniband/hw/hfi1/user_sdma.c | 8 ++--- drivers/infiniband/hw/qib/qib_ruc.c | 2 +- drivers/infiniband/hw/qib/qib_uc.c | 4 +-- drivers/infiniband/hw/qib/qib_ud.c | 4 +-- drivers/infiniband/sw/rdmavt/qp.c | 6 ++-- drivers/input/misc/regulator-haptic.c | 2 +- drivers/md/dm-bufio.c | 10 +++--- drivers/md/dm-kcopyd.c | 4 +-- drivers/md/dm-stats.c | 36 +++++++++---------- drivers/md/dm-switch.c | 2 +- drivers/md/dm-thin.c | 2 +- drivers/md/dm-verity-target.c | 2 +- drivers/md/dm.c | 4 +-- drivers/md/md.c | 2 +- drivers/md/raid5.c | 2 +- drivers/misc/mic/scif/scif_rb.c | 8 ++--- drivers/misc/mic/scif/scif_rma_list.c | 2 +- drivers/net/bonding/bond_alb.c | 2 +- drivers/net/bonding/bond_main.c | 6 ++-- drivers/net/ethernet/chelsio/cxgb4/sge.c | 4 +-- drivers/net/ethernet/emulex/benet/be_main.c | 2 +- drivers/net/ethernet/hisilicon/hip04_eth.c | 4 +-- .../net/ethernet/intel/i40e/i40e_debugfs.c | 4 +-- .../net/ethernet/intel/i40e/i40e_ethtool.c | 2 +- drivers/net/ethernet/intel/i40e/i40e_main.c | 4 +-- drivers/net/ethernet/intel/i40e/i40e_ptp.c | 4 +-- drivers/net/ethernet/intel/igb/e1000_regs.h | 2 +- drivers/net/ethernet/intel/igb/igb_main.c | 2 +- .../net/ethernet/intel/ixgbe/ixgbe_common.h | 4 +-- drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 8 ++--- drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c | 4 +-- .../net/ethernet/intel/ixgbevf/ixgbevf_main.c | 2 +- drivers/net/ethernet/intel/ixgbevf/vf.h | 2 +- drivers/net/ethernet/mellanox/mlx4/en_tx.c | 12 +++---- .../net/ethernet/neterion/vxge/vxge-main.c | 2 +- drivers/net/ethernet/sfc/ef10.c | 10 +++--- drivers/net/ethernet/sfc/efx.c | 4 +-- drivers/net/ethernet/sfc/falcon/efx.c | 4 +-- drivers/net/ethernet/sfc/falcon/falcon.c | 4 +-- drivers/net/ethernet/sfc/falcon/farch.c | 8 ++--- drivers/net/ethernet/sfc/falcon/nic.h | 6 ++-- drivers/net/ethernet/sfc/falcon/tx.c | 6 ++-- drivers/net/ethernet/sfc/farch.c | 8 ++--- drivers/net/ethernet/sfc/nic.h | 6 ++-- drivers/net/ethernet/sfc/ptp.c | 10 +++--- drivers/net/ethernet/sfc/tx.c | 6 ++-- drivers/net/ethernet/sun/niu.c | 4 +-- drivers/net/tap.c | 2 +- drivers/net/tun.c | 4 +-- drivers/net/wireless/ath/ath5k/desc.c | 8 ++--- .../broadcom/brcm80211/brcmfmac/sdio.c | 2 +- drivers/net/wireless/intel/iwlwifi/mvm/ops.c | 2 +- drivers/net/wireless/intel/iwlwifi/mvm/tx.c | 4 +-- drivers/net/wireless/intel/iwlwifi/pcie/rx.c | 2 +- .../net/wireless/intel/iwlwifi/pcie/trans.c | 10 +++--- drivers/net/wireless/mac80211_hwsim.c | 4 +-- drivers/scsi/qla2xxx/qla_target.c | 2 +- drivers/target/target_core_user.c | 2 +- drivers/usb/class/cdc-wdm.c | 2 +- drivers/usb/core/devio.c | 2 +- drivers/usb/core/sysfs.c | 4 +-- drivers/usb/gadget/udc/gr_udc.c | 4 +-- drivers/usb/host/ohci-hcd.c | 2 +- drivers/usb/host/uhci-hcd.h | 4 +-- drivers/vfio/vfio.c | 2 +- drivers/vhost/scsi.c | 2 +- fs/aio.c | 2 +- fs/buffer.c | 3 +- fs/crypto/keyinfo.c | 2 +- fs/direct-io.c | 2 +- fs/exec.c | 2 +- fs/fcntl.c | 2 +- fs/fs_pin.c | 4 +-- fs/fuse/dev.c | 2 +- fs/inode.c | 2 +- fs/namei.c | 4 +-- fs/namespace.c | 2 +- fs/nfs/dir.c | 8 ++--- fs/proc/array.c | 2 +- fs/proc_namespace.c | 2 +- fs/splice.c | 2 +- fs/userfaultfd.c | 8 ++--- fs/xfs/xfs_log_priv.h | 4 +-- include/linux/bitops.h | 4 +-- include/linux/dynamic_queue_limits.h | 2 +- include/linux/huge_mm.h | 2 +- include/linux/if_team.h | 2 +- include/linux/llist.h | 2 +- include/linux/pm_runtime.h | 2 +- include/net/ip_vs.h | 6 ++-- kernel/acct.c | 4 +-- kernel/events/core.c | 6 ++-- kernel/events/ring_buffer.c | 2 +- kernel/exit.c | 2 +- kernel/trace/ring_buffer.c | 2 +- kernel/trace/trace.h | 2 +- kernel/trace/trace_stack.c | 2 +- kernel/user_namespace.c | 2 +- lib/assoc_array.c | 20 +++++------ lib/dynamic_queue_limits.c | 2 +- lib/llist.c | 2 +- lib/vsprintf.c | 4 +-- mm/huge_memory.c | 2 +- net/core/dev.c | 2 +- net/core/pktgen.c | 2 +- net/ipv4/inet_fragment.c | 2 +- net/ipv4/route.c | 2 +- net/ipv4/tcp_output.c | 2 +- net/ipv4/udp.c | 4 +-- net/ipv6/ip6_tunnel.c | 8 ++--- net/ipv6/udp.c | 4 +-- net/llc/llc_input.c | 4 +-- net/mac80211/sta_info.c | 2 +- net/netlabel/netlabel_calipso.c | 2 +- net/wireless/nl80211.c | 2 +- sound/firewire/amdtp-am824.c | 6 ++-- sound/firewire/amdtp-stream.c | 23 ++++++------ sound/firewire/amdtp-stream.h | 2 +- sound/firewire/digi00x/amdtp-dot.c | 6 ++-- sound/firewire/fireface/amdtp-ff.c | 4 +-- sound/firewire/fireface/ff-midi.c | 10 +++--- sound/firewire/fireface/ff-transaction.c | 8 ++--- sound/firewire/isight.c | 18 +++++----- sound/firewire/motu/amdtp-motu.c | 4 +-- sound/firewire/oxfw/oxfw-scs1x.c | 12 +++---- sound/firewire/tascam/amdtp-tascam.c | 4 +-- sound/firewire/tascam/tascam-transaction.c | 6 ++-- sound/soc/xtensa/xtfpga-i2s.c | 6 ++-- sound/usb/bcd2000/bcd2000.c | 4 +-- tools/arch/x86/include/asm/atomic.h | 2 +- tools/include/asm-generic/atomic-gcc.h | 2 +- tools/perf/util/auxtrace.h | 4 +-- tools/perf/util/session.h | 2 +- virt/kvm/kvm_main.c | 2 +- 180 files changed, 383 insertions(+), 385 deletions(-) diff --git a/arch/arc/kernel/smp.c b/arch/arc/kernel/smp.c index f46267153ec2..94cabe73664b 100644 --- a/arch/arc/kernel/smp.c +++ b/arch/arc/kernel/smp.c @@ -245,7 +245,7 @@ static void ipi_send_msg_one(int cpu, enum ipi_msg_type msg) * and read back old value */ do { - new = old = ACCESS_ONCE(*ipi_data_ptr); + new = old = READ_ONCE(*ipi_data_ptr); new |= 1U << msg; } while (cmpxchg(ipi_data_ptr, old, new) != old); diff --git a/arch/arm/include/asm/spinlock.h b/arch/arm/include/asm/spinlock.h index daa87212c9a1..77f50ae0aeb4 100644 --- a/arch/arm/include/asm/spinlock.h +++ b/arch/arm/include/asm/spinlock.h @@ -71,7 +71,7 @@ static inline void arch_spin_lock(arch_spinlock_t *lock) while (lockval.tickets.next != lockval.tickets.owner) { wfe(); - lockval.tickets.owner = ACCESS_ONCE(lock->tickets.owner); + lockval.tickets.owner = READ_ONCE(lock->tickets.owner); } smp_mb(); diff --git a/arch/arm/mach-tegra/cpuidle-tegra20.c b/arch/arm/mach-tegra/cpuidle-tegra20.c index 76e4c83cd5c8..3f24addd7972 100644 --- a/arch/arm/mach-tegra/cpuidle-tegra20.c +++ b/arch/arm/mach-tegra/cpuidle-tegra20.c @@ -179,7 +179,7 @@ static int tegra20_idle_lp2_coupled(struct cpuidle_device *dev, bool entered_lp2 = false; if (tegra_pending_sgi()) - ACCESS_ONCE(abort_flag) = true; + WRITE_ONCE(abort_flag, true); cpuidle_coupled_parallel_barrier(dev, &abort_barrier); diff --git a/arch/arm/vdso/vgettimeofday.c b/arch/arm/vdso/vgettimeofday.c index 79214d5ff097..a9dd619c6c29 100644 --- a/arch/arm/vdso/vgettimeofday.c +++ b/arch/arm/vdso/vgettimeofday.c @@ -35,7 +35,7 @@ static notrace u32 __vdso_read_begin(const struct vdso_data *vdata) { u32 seq; repeat: - seq = ACCESS_ONCE(vdata->seq_count); + seq = READ_ONCE(vdata->seq_count); if (seq & 1) { cpu_relax(); goto repeat; diff --git a/arch/ia64/include/asm/spinlock.h b/arch/ia64/include/asm/spinlock.h index 35b31884863b..e98775be112d 100644 --- a/arch/ia64/include/asm/spinlock.h +++ b/arch/ia64/include/asm/spinlock.h @@ -61,7 +61,7 @@ static __always_inline void __ticket_spin_lock(arch_spinlock_t *lock) static __always_inline int __ticket_spin_trylock(arch_spinlock_t *lock) { - int tmp = ACCESS_ONCE(lock->lock); + int tmp = READ_ONCE(lock->lock); if (!(((tmp >> TICKET_SHIFT) ^ tmp) & TICKET_MASK)) return ia64_cmpxchg(acq, &lock->lock, tmp, tmp + 1, sizeof (tmp)) == tmp; @@ -73,19 +73,19 @@ static __always_inline void __ticket_spin_unlock(arch_spinlock_t *lock) unsigned short *p = (unsigned short *)&lock->lock + 1, tmp; asm volatile ("ld2.bias %0=[%1]" : "=r"(tmp) : "r"(p)); - ACCESS_ONCE(*p) = (tmp + 2) & ~1; + WRITE_ONCE(*p, (tmp + 2) & ~1); } static inline int __ticket_spin_is_locked(arch_spinlock_t *lock) { - long tmp = ACCESS_ONCE(lock->lock); + long tmp = READ_ONCE(lock->lock); return !!(((tmp >> TICKET_SHIFT) ^ tmp) & TICKET_MASK); } static inline int __ticket_spin_is_contended(arch_spinlock_t *lock) { - long tmp = ACCESS_ONCE(lock->lock); + long tmp = READ_ONCE(lock->lock); return ((tmp - (tmp >> TICKET_SHIFT)) & TICKET_MASK) > 1; } diff --git a/arch/mips/include/asm/vdso.h b/arch/mips/include/asm/vdso.h index b7cd6cf77b83..91bf0c2c265c 100644 --- a/arch/mips/include/asm/vdso.h +++ b/arch/mips/include/asm/vdso.h @@ -99,7 +99,7 @@ static inline u32 vdso_data_read_begin(const union mips_vdso_data *data) u32 seq; while (true) { - seq = ACCESS_ONCE(data->seq_count); + seq = READ_ONCE(data->seq_count); if (likely(!(seq & 1))) { /* Paired with smp_wmb() in vdso_data_write_*(). */ smp_rmb(); diff --git a/arch/mips/kernel/pm-cps.c b/arch/mips/kernel/pm-cps.c index 4655017f2377..1d2996cd58da 100644 --- a/arch/mips/kernel/pm-cps.c +++ b/arch/mips/kernel/pm-cps.c @@ -166,7 +166,7 @@ int cps_pm_enter_state(enum cps_pm_state state) nc_core_ready_count = nc_addr; /* Ensure ready_count is zero-initialised before the assembly runs */ - ACCESS_ONCE(*nc_core_ready_count) = 0; + WRITE_ONCE(*nc_core_ready_count, 0); coupled_barrier(&per_cpu(pm_barrier, core), online); /* Run the generated entry code */ diff --git a/arch/mn10300/kernel/mn10300-serial.c b/arch/mn10300/kernel/mn10300-serial.c index 7ecf69879e2d..d7ef1232a82a 100644 --- a/arch/mn10300/kernel/mn10300-serial.c +++ b/arch/mn10300/kernel/mn10300-serial.c @@ -543,7 +543,7 @@ static void mn10300_serial_receive_interrupt(struct mn10300_serial_port *port) try_again: /* pull chars out of the hat */ - ix = ACCESS_ONCE(port->rx_outp); + ix = READ_ONCE(port->rx_outp); if (CIRC_CNT(port->rx_inp, ix, MNSC_BUFFER_SIZE) == 0) { if (push && !tport->low_latency) tty_flip_buffer_push(tport); @@ -1724,7 +1724,7 @@ static int mn10300_serial_poll_get_char(struct uart_port *_port) if (mn10300_serial_int_tbl[port->rx_irq].port != NULL) { do { /* pull chars out of the hat */ - ix = ACCESS_ONCE(port->rx_outp); + ix = READ_ONCE(port->rx_outp); if (CIRC_CNT(port->rx_inp, ix, MNSC_BUFFER_SIZE) == 0) return NO_POLL_CHAR; diff --git a/arch/parisc/include/asm/atomic.h b/arch/parisc/include/asm/atomic.h index 17b98a87e5e2..c57d4e8307f2 100644 --- a/arch/parisc/include/asm/atomic.h +++ b/arch/parisc/include/asm/atomic.h @@ -260,7 +260,7 @@ atomic64_set(atomic64_t *v, s64 i) static __inline__ s64 atomic64_read(const atomic64_t *v) { - return ACCESS_ONCE((v)->counter); + return READ_ONCE((v)->counter); } #define atomic64_inc(v) (atomic64_add( 1,(v))) diff --git a/arch/powerpc/platforms/powernv/opal-msglog.c b/arch/powerpc/platforms/powernv/opal-msglog.c index 7a9cde0cfbd1..acd3206dfae3 100644 --- a/arch/powerpc/platforms/powernv/opal-msglog.c +++ b/arch/powerpc/platforms/powernv/opal-msglog.c @@ -43,7 +43,7 @@ ssize_t opal_msglog_copy(char *to, loff_t pos, size_t count) if (!opal_memcons) return -ENODEV; - out_pos = be32_to_cpu(ACCESS_ONCE(opal_memcons->out_pos)); + out_pos = be32_to_cpu(READ_ONCE(opal_memcons->out_pos)); /* Now we've read out_pos, put a barrier in before reading the new * data it points to in conbuf. */ diff --git a/arch/s390/include/asm/spinlock.h b/arch/s390/include/asm/spinlock.h index 9fa855f91e55..66f4160010ef 100644 --- a/arch/s390/include/asm/spinlock.h +++ b/arch/s390/include/asm/spinlock.h @@ -117,14 +117,14 @@ extern int _raw_write_trylock_retry(arch_rwlock_t *lp); static inline int arch_read_trylock_once(arch_rwlock_t *rw) { - int old = ACCESS_ONCE(rw->lock); + int old = READ_ONCE(rw->lock); return likely(old >= 0 && __atomic_cmpxchg_bool(&rw->lock, old, old + 1)); } static inline int arch_write_trylock_once(arch_rwlock_t *rw) { - int old = ACCESS_ONCE(rw->lock); + int old = READ_ONCE(rw->lock); return likely(old == 0 && __atomic_cmpxchg_bool(&rw->lock, 0, 0x80000000)); } @@ -211,7 +211,7 @@ static inline void arch_read_unlock(arch_rwlock_t *rw) int old; do { - old = ACCESS_ONCE(rw->lock); + old = READ_ONCE(rw->lock); } while (!__atomic_cmpxchg_bool(&rw->lock, old, old - 1)); } diff --git a/arch/s390/lib/spinlock.c b/arch/s390/lib/spinlock.c index b12663d653d8..34e30b9ea234 100644 --- a/arch/s390/lib/spinlock.c +++ b/arch/s390/lib/spinlock.c @@ -162,8 +162,8 @@ void _raw_read_lock_wait(arch_rwlock_t *rw) smp_yield_cpu(~owner); count = spin_retry; } - old = ACCESS_ONCE(rw->lock); - owner = ACCESS_ONCE(rw->owner); + old = READ_ONCE(rw->lock); + owner = READ_ONCE(rw->owner); if (old < 0) continue; if (__atomic_cmpxchg_bool(&rw->lock, old, old + 1)) @@ -178,7 +178,7 @@ int _raw_read_trylock_retry(arch_rwlock_t *rw) int old; while (count-- > 0) { - old = ACCESS_ONCE(rw->lock); + old = READ_ONCE(rw->lock); if (old < 0) continue; if (__atomic_cmpxchg_bool(&rw->lock, old, old + 1)) @@ -202,8 +202,8 @@ void _raw_write_lock_wait(arch_rwlock_t *rw, int prev) smp_yield_cpu(~owner); count = spin_retry; } - old = ACCESS_ONCE(rw->lock); - owner = ACCESS_ONCE(rw->owner); + old = READ_ONCE(rw->lock); + owner = READ_ONCE(rw->owner); smp_mb(); if (old >= 0) { prev = __RAW_LOCK(&rw->lock, 0x80000000, __RAW_OP_OR); @@ -230,8 +230,8 @@ void _raw_write_lock_wait(arch_rwlock_t *rw) smp_yield_cpu(~owner); count = spin_retry; } - old = ACCESS_ONCE(rw->lock); - owner = ACCESS_ONCE(rw->owner); + old = READ_ONCE(rw->lock); + owner = READ_ONCE(rw->owner); if (old >= 0 && __atomic_cmpxchg_bool(&rw->lock, old, old | 0x80000000)) prev = old; @@ -251,7 +251,7 @@ int _raw_write_trylock_retry(arch_rwlock_t *rw) int old; while (count-- > 0) { - old = ACCESS_ONCE(rw->lock); + old = READ_ONCE(rw->lock); if (old) continue; if (__atomic_cmpxchg_bool(&rw->lock, 0, 0x80000000)) diff --git a/arch/sparc/include/asm/atomic_32.h b/arch/sparc/include/asm/atomic_32.h index 7643e979e333..e2f398e9456c 100644 --- a/arch/sparc/include/asm/atomic_32.h +++ b/arch/sparc/include/asm/atomic_32.h @@ -31,7 +31,7 @@ void atomic_set(atomic_t *, int); #define atomic_set_release(v, i) atomic_set((v), (i)) -#define atomic_read(v) ACCESS_ONCE((v)->counter) +#define atomic_read(v) READ_ONCE((v)->counter) #define atomic_add(i, v) ((void)atomic_add_return( (int)(i), (v))) #define atomic_sub(i, v) ((void)atomic_add_return(-(int)(i), (v))) diff --git a/arch/tile/gxio/dma_queue.c b/arch/tile/gxio/dma_queue.c index baa60357f8ba..b7ba577d82ca 100644 --- a/arch/tile/gxio/dma_queue.c +++ b/arch/tile/gxio/dma_queue.c @@ -163,14 +163,14 @@ int __gxio_dma_queue_is_complete(__gxio_dma_queue_t *dma_queue, int64_t completion_slot, int update) { if (update) { - if (ACCESS_ONCE(dma_queue->hw_complete_count) > + if (READ_ONCE(dma_queue->hw_complete_count) > completion_slot) return 1; __gxio_dma_queue_update_credits(dma_queue); } - return ACCESS_ONCE(dma_queue->hw_complete_count) > completion_slot; + return READ_ONCE(dma_queue->hw_complete_count) > completion_slot; } EXPORT_SYMBOL_GPL(__gxio_dma_queue_is_complete); diff --git a/arch/tile/include/gxio/dma_queue.h b/arch/tile/include/gxio/dma_queue.h index b9e45e37649e..c8fd47edba30 100644 --- a/arch/tile/include/gxio/dma_queue.h +++ b/arch/tile/include/gxio/dma_queue.h @@ -121,7 +121,7 @@ static inline int64_t __gxio_dma_queue_reserve(__gxio_dma_queue_t *dma_queue, * if the result is LESS than "hw_complete_count". */ uint64_t complete; - complete = ACCESS_ONCE(dma_queue->hw_complete_count); + complete = READ_ONCE(dma_queue->hw_complete_count); slot |= (complete & 0xffffffffff000000); if (slot < complete) slot += 0x1000000; diff --git a/arch/tile/kernel/ptrace.c b/arch/tile/kernel/ptrace.c index e1a078e6828e..d516d61751c2 100644 --- a/arch/tile/kernel/ptrace.c +++ b/arch/tile/kernel/ptrace.c @@ -255,7 +255,7 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request, int do_syscall_trace_enter(struct pt_regs *regs) { - u32 work = ACCESS_ONCE(current_thread_info()->flags); + u32 work = READ_ONCE(current_thread_info()->flags); if ((work & _TIF_SYSCALL_TRACE) && tracehook_report_syscall_entry(regs)) { diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index 03505ffbe1b6..eaa0ba66cf96 100644 --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -75,7 +75,7 @@ static long syscall_trace_enter(struct pt_regs *regs) if (IS_ENABLED(CONFIG_DEBUG_ENTRY)) BUG_ON(regs != task_pt_regs(current)); - work = ACCESS_ONCE(ti->flags) & _TIF_WORK_SYSCALL_ENTRY; + work = READ_ONCE(ti->flags) & _TIF_WORK_SYSCALL_ENTRY; if (unlikely(work & _TIF_SYSCALL_EMU)) emulated = true; diff --git a/arch/x86/entry/vdso/vclock_gettime.c b/arch/x86/entry/vdso/vclock_gettime.c index fa8dbfcf7ed3..11b13c4b43d5 100644 --- a/arch/x86/entry/vdso/vclock_gettime.c +++ b/arch/x86/entry/vdso/vclock_gettime.c @@ -318,7 +318,7 @@ int gettimeofday(struct timeval *, struct timezone *) notrace time_t __vdso_time(time_t *t) { /* This is atomic on x86 so we don't need any locks. */ - time_t result = ACCESS_ONCE(gtod->wall_time_sec); + time_t result = READ_ONCE(gtod->wall_time_sec); if (t) *t = result; diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c index 589af1eec7c1..140d33288e78 100644 --- a/arch/x86/events/core.c +++ b/arch/x86/events/core.c @@ -2118,7 +2118,7 @@ static int x86_pmu_event_init(struct perf_event *event) event->destroy(event); } - if (ACCESS_ONCE(x86_pmu.attr_rdpmc)) + if (READ_ONCE(x86_pmu.attr_rdpmc)) event->hw.flags |= PERF_X86_EVENT_RDPMC_ALLOWED; return err; diff --git a/arch/x86/include/asm/vgtod.h b/arch/x86/include/asm/vgtod.h index 022e59714562..53dd162576a8 100644 --- a/arch/x86/include/asm/vgtod.h +++ b/arch/x86/include/asm/vgtod.h @@ -48,7 +48,7 @@ static inline unsigned gtod_read_begin(const struct vsyscall_gtod_data *s) unsigned ret; repeat: - ret = ACCESS_ONCE(s->seq); + ret = READ_ONCE(s->seq); if (unlikely(ret & 1)) { cpu_relax(); goto repeat; diff --git a/arch/x86/kernel/espfix_64.c b/arch/x86/kernel/espfix_64.c index 9c4e7ba6870c..7d7715dde901 100644 --- a/arch/x86/kernel/espfix_64.c +++ b/arch/x86/kernel/espfix_64.c @@ -155,14 +155,14 @@ void init_espfix_ap(int cpu) page = cpu/ESPFIX_STACKS_PER_PAGE; /* Did another CPU already set this up? */ - stack_page = ACCESS_ONCE(espfix_pages[page]); + stack_page = READ_ONCE(espfix_pages[page]); if (likely(stack_page)) goto done; mutex_lock(&espfix_init_mutex); /* Did we race on the lock? */ - stack_page = ACCESS_ONCE(espfix_pages[page]); + stack_page = READ_ONCE(espfix_pages[page]); if (stack_page) goto unlock_done; @@ -200,7 +200,7 @@ void init_espfix_ap(int cpu) set_pte(&pte_p[n*PTE_STRIDE], pte); /* Job is done for this CPU and any CPU which shares this page */ - ACCESS_ONCE(espfix_pages[page]) = stack_page; + WRITE_ONCE(espfix_pages[page], stack_page); unlock_done: mutex_unlock(&espfix_init_mutex); diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c index 35aafc95e4b8..18bc9b51ac9b 100644 --- a/arch/x86/kernel/nmi.c +++ b/arch/x86/kernel/nmi.c @@ -105,7 +105,7 @@ static void nmi_max_handler(struct irq_work *w) { struct nmiaction *a = container_of(w, struct nmiaction, irq_work); int remainder_ns, decimal_msecs; - u64 whole_msecs = ACCESS_ONCE(a->max_duration); + u64 whole_msecs = READ_ONCE(a->max_duration); remainder_ns = do_div(whole_msecs, (1000 * 1000)); decimal_msecs = remainder_ns / 1000; diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 7a69cf053711..a119b361b8b7 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -443,7 +443,7 @@ static u64 __update_clear_spte_slow(u64 *sptep, u64 spte) static u64 __get_spte_lockless(u64 *sptep) { - return ACCESS_ONCE(*sptep); + return READ_ONCE(*sptep); } #else union split_spte { @@ -4819,7 +4819,7 @@ static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, * If we don't have indirect shadow pages, it means no page is * write-protected, so we can exit simply. */ - if (!ACCESS_ONCE(vcpu->kvm->arch.indirect_shadow_pages)) + if (!READ_ONCE(vcpu->kvm->arch.indirect_shadow_pages)) return; remote_flush = local_flush = false; diff --git a/arch/x86/kvm/page_track.c b/arch/x86/kvm/page_track.c index ea67dc876316..01c1371f39f8 100644 --- a/arch/x86/kvm/page_track.c +++ b/arch/x86/kvm/page_track.c @@ -157,7 +157,7 @@ bool kvm_page_track_is_active(struct kvm_vcpu *vcpu, gfn_t gfn, return false; index = gfn_to_index(gfn, slot->base_gfn, PT_PAGE_TABLE_LEVEL); - return !!ACCESS_ONCE(slot->arch.gfn_track[mode][index]); + return !!READ_ONCE(slot->arch.gfn_track[mode][index]); } void kvm_page_track_cleanup(struct kvm *kvm) diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c index 6083ba462f35..13b4f19b9131 100644 --- a/arch/x86/xen/p2m.c +++ b/arch/x86/xen/p2m.c @@ -547,7 +547,7 @@ int xen_alloc_p2m_entry(unsigned long pfn) if (p2m_top_mfn && pfn < MAX_P2M_PFN) { topidx = p2m_top_index(pfn); top_mfn_p = &p2m_top_mfn[topidx]; - mid_mfn = ACCESS_ONCE(p2m_top_mfn_p[topidx]); + mid_mfn = READ_ONCE(p2m_top_mfn_p[topidx]); BUG_ON(virt_to_mfn(mid_mfn) != *top_mfn_p); diff --git a/arch/xtensa/platforms/xtfpga/lcd.c b/arch/xtensa/platforms/xtfpga/lcd.c index 4dc0c1b43f4b..2f7eb66c23ec 100644 --- a/arch/xtensa/platforms/xtfpga/lcd.c +++ b/arch/xtensa/platforms/xtfpga/lcd.c @@ -34,23 +34,23 @@ static void lcd_put_byte(u8 *addr, u8 data) { #ifdef CONFIG_XTFPGA_LCD_8BIT_ACCESS - ACCESS_ONCE(*addr) = data; + WRITE_ONCE(*addr, data); #else - ACCESS_ONCE(*addr) = data & 0xf0; - ACCESS_ONCE(*addr) = (data << 4) & 0xf0; + WRITE_ONCE(*addr, data & 0xf0); + WRITE_ONCE(*addr, (data << 4) & 0xf0); #endif } static int __init lcd_init(void) { - ACCESS_ONCE(*LCD_INSTR_ADDR) = LCD_DISPLAY_MODE8BIT; + WRITE_ONCE(*LCD_INSTR_ADDR, LCD_DISPLAY_MODE8BIT); mdelay(5); - ACCESS_ONCE(*LCD_INSTR_ADDR) = LCD_DISPLAY_MODE8BIT; + WRITE_ONCE(*LCD_INSTR_ADDR, LCD_DISPLAY_MODE8BIT); udelay(200); - ACCESS_ONCE(*LCD_INSTR_ADDR) = LCD_DISPLAY_MODE8BIT; + WRITE_ONCE(*LCD_INSTR_ADDR, LCD_DISPLAY_MODE8BIT); udelay(50); #ifndef CONFIG_XTFPGA_LCD_8BIT_ACCESS - ACCESS_ONCE(*LCD_INSTR_ADDR) = LCD_DISPLAY_MODE4BIT; + WRITE_ONCE(*LCD_INSTR_ADDR, LCD_DISPLAY_MODE4BIT); udelay(50); lcd_put_byte(LCD_INSTR_ADDR, LCD_DISPLAY_MODE4BIT); udelay(50); diff --git a/block/blk-wbt.c b/block/blk-wbt.c index 6a9a0f03a67b..d822530e6aea 100644 --- a/block/blk-wbt.c +++ b/block/blk-wbt.c @@ -261,7 +261,7 @@ static inline bool stat_sample_valid(struct blk_rq_stat *stat) static u64 rwb_sync_issue_lat(struct rq_wb *rwb) { - u64 now, issue = ACCESS_ONCE(rwb->sync_issue); + u64 now, issue = READ_ONCE(rwb->sync_issue); if (!issue || !rwb->sync_cookie) return 0; diff --git a/drivers/base/core.c b/drivers/base/core.c index 12ebd055724c..4b8ba2a75a4d 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -668,7 +668,7 @@ const char *dev_driver_string(const struct device *dev) * so be careful about accessing it. dev->bus and dev->class should * never change once they are set, so they don't need special care. */ - drv = ACCESS_ONCE(dev->driver); + drv = READ_ONCE(dev->driver); return drv ? drv->name : (dev->bus ? dev->bus->name : (dev->class ? dev->class->name : "")); diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 7bcf80fa9ada..41d7c2b99f69 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -134,11 +134,11 @@ unsigned long pm_runtime_autosuspend_expiration(struct device *dev) if (!dev->power.use_autosuspend) goto out; - autosuspend_delay = ACCESS_ONCE(dev->power.autosuspend_delay); + autosuspend_delay = READ_ONCE(dev->power.autosuspend_delay); if (autosuspend_delay < 0) goto out; - last_busy = ACCESS_ONCE(dev->power.last_busy); + last_busy = READ_ONCE(dev->power.last_busy); elapsed = jiffies - last_busy; if (elapsed < 0) goto out; /* jiffies has wrapped around. */ diff --git a/drivers/char/random.c b/drivers/char/random.c index 8ad92707e45f..6c7ccac2679e 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -641,7 +641,7 @@ static void credit_entropy_bits(struct entropy_store *r, int nbits) return; retry: - entropy_count = orig = ACCESS_ONCE(r->entropy_count); + entropy_count = orig = READ_ONCE(r->entropy_count); if (nfrac < 0) { /* Debit */ entropy_count += nfrac; @@ -1265,7 +1265,7 @@ static size_t account(struct entropy_store *r, size_t nbytes, int min, /* Can we pull enough? */ retry: - entropy_count = orig = ACCESS_ONCE(r->entropy_count); + entropy_count = orig = READ_ONCE(r->entropy_count); ibytes = nbytes; /* never pull more than available */ have_bytes = entropy_count >> (ENTROPY_SHIFT + 3); diff --git a/drivers/clocksource/bcm2835_timer.c b/drivers/clocksource/bcm2835_timer.c index 39e489a96ad7..60da2537bef9 100644 --- a/drivers/clocksource/bcm2835_timer.c +++ b/drivers/clocksource/bcm2835_timer.c @@ -71,7 +71,7 @@ static irqreturn_t bcm2835_time_interrupt(int irq, void *dev_id) if (readl_relaxed(timer->control) & timer->match_mask) { writel_relaxed(timer->match_mask, timer->control); - event_handler = ACCESS_ONCE(timer->evt.event_handler); + event_handler = READ_ONCE(timer->evt.event_handler); if (event_handler) event_handler(&timer->evt); return IRQ_HANDLED; diff --git a/drivers/crypto/caam/jr.c b/drivers/crypto/caam/jr.c index d258953ff488..f4f258075b89 100644 --- a/drivers/crypto/caam/jr.c +++ b/drivers/crypto/caam/jr.c @@ -172,7 +172,7 @@ static void caam_jr_dequeue(unsigned long devarg) while (rd_reg32(&jrp->rregs->outring_used)) { - head = ACCESS_ONCE(jrp->head); + head = READ_ONCE(jrp->head); spin_lock(&jrp->outlock); @@ -341,7 +341,7 @@ int caam_jr_enqueue(struct device *dev, u32 *desc, spin_lock_bh(&jrp->inplock); head = jrp->head; - tail = ACCESS_ONCE(jrp->tail); + tail = READ_ONCE(jrp->tail); if (!rd_reg32(&jrp->rregs->inpring_avail) || CIRC_SPACE(head, tail, JOBR_DEPTH) <= 0) { diff --git a/drivers/crypto/nx/nx-842-powernv.c b/drivers/crypto/nx/nx-842-powernv.c index 874ddf5e9087..0f20f5ec9617 100644 --- a/drivers/crypto/nx/nx-842-powernv.c +++ b/drivers/crypto/nx/nx-842-powernv.c @@ -193,7 +193,7 @@ static int wait_for_csb(struct nx842_workmem *wmem, ktime_t start = wmem->start, now = ktime_get(); ktime_t timeout = ktime_add_ms(start, CSB_WAIT_MAX); - while (!(ACCESS_ONCE(csb->flags) & CSB_V)) { + while (!(READ_ONCE(csb->flags) & CSB_V)) { cpu_relax(); now = ktime_get(); if (ktime_after(now, timeout)) diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c index 8bf89267dc25..ccf52368a073 100644 --- a/drivers/firewire/ohci.c +++ b/drivers/firewire/ohci.c @@ -734,7 +734,7 @@ static unsigned int ar_search_last_active_buffer(struct ar_context *ctx, __le16 res_count, next_res_count; i = ar_first_buffer_index(ctx); - res_count = ACCESS_ONCE(ctx->descriptors[i].res_count); + res_count = READ_ONCE(ctx->descriptors[i].res_count); /* A buffer that is not yet completely filled must be the last one. */ while (i != last && res_count == 0) { @@ -742,8 +742,7 @@ static unsigned int ar_search_last_active_buffer(struct ar_context *ctx, /* Peek at the next descriptor. */ next_i = ar_next_buffer_index(i); rmb(); /* read descriptors in order */ - next_res_count = ACCESS_ONCE( - ctx->descriptors[next_i].res_count); + next_res_count = READ_ONCE(ctx->descriptors[next_i].res_count); /* * If the next descriptor is still empty, we must stop at this * descriptor. @@ -759,8 +758,7 @@ static unsigned int ar_search_last_active_buffer(struct ar_context *ctx, if (MAX_AR_PACKET_SIZE > PAGE_SIZE && i != last) { next_i = ar_next_buffer_index(next_i); rmb(); - next_res_count = ACCESS_ONCE( - ctx->descriptors[next_i].res_count); + next_res_count = READ_ONCE(ctx->descriptors[next_i].res_count); if (next_res_count != cpu_to_le16(PAGE_SIZE)) goto next_buffer_is_active; } @@ -2812,7 +2810,7 @@ static int handle_ir_buffer_fill(struct context *context, u32 buffer_dma; req_count = le16_to_cpu(last->req_count); - res_count = le16_to_cpu(ACCESS_ONCE(last->res_count)); + res_count = le16_to_cpu(READ_ONCE(last->res_count)); completed = req_count - res_count; buffer_dma = le32_to_cpu(last->data_address); diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c index 333bad749067..303b5e099a98 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c @@ -260,7 +260,7 @@ static void amdgpu_fence_fallback(unsigned long arg) */ int amdgpu_fence_wait_empty(struct amdgpu_ring *ring) { - uint64_t seq = ACCESS_ONCE(ring->fence_drv.sync_seq); + uint64_t seq = READ_ONCE(ring->fence_drv.sync_seq); struct dma_fence *fence, **ptr; int r; @@ -300,7 +300,7 @@ unsigned amdgpu_fence_count_emitted(struct amdgpu_ring *ring) amdgpu_fence_process(ring); emitted = 0x100000000ull; emitted -= atomic_read(&ring->fence_drv.last_seq); - emitted += ACCESS_ONCE(ring->fence_drv.sync_seq); + emitted += READ_ONCE(ring->fence_drv.sync_seq); return lower_32_bits(emitted); } diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c index 7171968f261e..6149a47fe63d 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c @@ -788,11 +788,11 @@ static int amdgpu_debugfs_gem_bo_info(int id, void *ptr, void *data) seq_printf(m, "\t0x%08x: %12ld byte %s", id, amdgpu_bo_size(bo), placement); - offset = ACCESS_ONCE(bo->tbo.mem.start); + offset = READ_ONCE(bo->tbo.mem.start); if (offset != AMDGPU_BO_INVALID_OFFSET) seq_printf(m, " @ 0x%010Lx", offset); - pin_count = ACCESS_ONCE(bo->pin_count); + pin_count = READ_ONCE(bo->pin_count); if (pin_count) seq_printf(m, " pin count %d", pin_count); seq_printf(m, "\n"); diff --git a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c index 38cea6fb25a8..a25f6c72f219 100644 --- a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c +++ b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c @@ -187,7 +187,7 @@ static bool amd_sched_entity_is_ready(struct amd_sched_entity *entity) if (kfifo_is_empty(&entity->job_queue)) return false; - if (ACCESS_ONCE(entity->dependency)) + if (READ_ONCE(entity->dependency)) return false; return true; diff --git a/drivers/gpu/drm/radeon/radeon_gem.c b/drivers/gpu/drm/radeon/radeon_gem.c index 3386452bd2f0..cf3deb283da5 100644 --- a/drivers/gpu/drm/radeon/radeon_gem.c +++ b/drivers/gpu/drm/radeon/radeon_gem.c @@ -451,7 +451,7 @@ int radeon_gem_busy_ioctl(struct drm_device *dev, void *data, else r = 0; - cur_placement = ACCESS_ONCE(robj->tbo.mem.mem_type); + cur_placement = READ_ONCE(robj->tbo.mem.mem_type); args->domain = radeon_mem_type_to_domain(cur_placement); drm_gem_object_put_unlocked(gobj); return r; @@ -481,7 +481,7 @@ int radeon_gem_wait_idle_ioctl(struct drm_device *dev, void *data, r = ret; /* Flush HDP cache via MMIO if necessary */ - cur_placement = ACCESS_ONCE(robj->tbo.mem.mem_type); + cur_placement = READ_ONCE(robj->tbo.mem.mem_type); if (rdev->asic->mmio_hdp_flush && radeon_mem_type_to_domain(cur_placement) == RADEON_GEM_DOMAIN_VRAM) robj->rdev->asic->mmio_hdp_flush(rdev); diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c index a552e4ea5440..6ac094ee8983 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c @@ -904,7 +904,7 @@ vmw_surface_handle_reference(struct vmw_private *dev_priv, if (unlikely(drm_is_render_client(file_priv))) require_exist = true; - if (ACCESS_ONCE(vmw_fpriv(file_priv)->locked_master)) { + if (READ_ONCE(vmw_fpriv(file_priv)->locked_master)) { DRM_ERROR("Locked master refused legacy " "surface reference.\n"); return -EACCES; diff --git a/drivers/infiniband/hw/hfi1/file_ops.c b/drivers/infiniband/hw/hfi1/file_ops.c index d9a1e9893136..97bea2e1aa6a 100644 --- a/drivers/infiniband/hw/hfi1/file_ops.c +++ b/drivers/infiniband/hw/hfi1/file_ops.c @@ -380,7 +380,7 @@ static long hfi1_file_ioctl(struct file *fp, unsigned int cmd, if (sc->flags & SCF_FROZEN) { wait_event_interruptible_timeout( dd->event_queue, - !(ACCESS_ONCE(dd->flags) & HFI1_FROZEN), + !(READ_ONCE(dd->flags) & HFI1_FROZEN), msecs_to_jiffies(SEND_CTXT_HALT_TIMEOUT)); if (dd->flags & HFI1_FROZEN) return -ENOLCK; diff --git a/drivers/infiniband/hw/hfi1/pio.c b/drivers/infiniband/hw/hfi1/pio.c index 7108a4b5e94c..75e740780285 100644 --- a/drivers/infiniband/hw/hfi1/pio.c +++ b/drivers/infiniband/hw/hfi1/pio.c @@ -1423,14 +1423,14 @@ struct pio_buf *sc_buffer_alloc(struct send_context *sc, u32 dw_len, goto done; } /* copy from receiver cache line and recalculate */ - sc->alloc_free = ACCESS_ONCE(sc->free); + sc->alloc_free = READ_ONCE(sc->free); avail = (unsigned long)sc->credits - (sc->fill - sc->alloc_free); if (blocks > avail) { /* still no room, actively update */ sc_release_update(sc); - sc->alloc_free = ACCESS_ONCE(sc->free); + sc->alloc_free = READ_ONCE(sc->free); trycount++; goto retry; } @@ -1667,7 +1667,7 @@ void sc_release_update(struct send_context *sc) /* call sent buffer callbacks */ code = -1; /* code not yet set */ - head = ACCESS_ONCE(sc->sr_head); /* snapshot the head */ + head = READ_ONCE(sc->sr_head); /* snapshot the head */ tail = sc->sr_tail; while (head != tail) { pbuf = &sc->sr[tail].pbuf; diff --git a/drivers/infiniband/hw/hfi1/ruc.c b/drivers/infiniband/hw/hfi1/ruc.c index b3291f0fde9a..a7fc664f0d4e 100644 --- a/drivers/infiniband/hw/hfi1/ruc.c +++ b/drivers/infiniband/hw/hfi1/ruc.c @@ -363,7 +363,7 @@ static void ruc_loopback(struct rvt_qp *sqp) again: smp_read_barrier_depends(); /* see post_one_send() */ - if (sqp->s_last == ACCESS_ONCE(sqp->s_head)) + if (sqp->s_last == READ_ONCE(sqp->s_head)) goto clr_busy; wqe = rvt_get_swqe_ptr(sqp, sqp->s_last); diff --git a/drivers/infiniband/hw/hfi1/sdma.c b/drivers/infiniband/hw/hfi1/sdma.c index 6781bcdb10b3..08346d25441c 100644 --- a/drivers/infiniband/hw/hfi1/sdma.c +++ b/drivers/infiniband/hw/hfi1/sdma.c @@ -1725,7 +1725,7 @@ static inline u16 sdma_gethead(struct sdma_engine *sde) swhead = sde->descq_head & sde->sdma_mask; /* this code is really bad for cache line trading */ - swtail = ACCESS_ONCE(sde->descq_tail) & sde->sdma_mask; + swtail = READ_ONCE(sde->descq_tail) & sde->sdma_mask; cnt = sde->descq_cnt; if (swhead < swtail) @@ -1872,7 +1872,7 @@ static void sdma_make_progress(struct sdma_engine *sde, u64 status) if ((status & sde->idle_mask) && !idle_check_done) { u16 swtail; - swtail = ACCESS_ONCE(sde->descq_tail) & sde->sdma_mask; + swtail = READ_ONCE(sde->descq_tail) & sde->sdma_mask; if (swtail != hwhead) { hwhead = (u16)read_sde_csr(sde, SD(HEAD)); idle_check_done = 1; @@ -2222,7 +2222,7 @@ void sdma_seqfile_dump_sde(struct seq_file *s, struct sdma_engine *sde) u16 len; head = sde->descq_head & sde->sdma_mask; - tail = ACCESS_ONCE(sde->descq_tail) & sde->sdma_mask; + tail = READ_ONCE(sde->descq_tail) & sde->sdma_mask; seq_printf(s, SDE_FMT, sde->this_idx, sde->cpu, sdma_state_name(sde->state.current_state), @@ -3305,7 +3305,7 @@ int sdma_ahg_alloc(struct sdma_engine *sde) return -EINVAL; } while (1) { - nr = ffz(ACCESS_ONCE(sde->ahg_bits)); + nr = ffz(READ_ONCE(sde->ahg_bits)); if (nr > 31) { trace_hfi1_ahg_allocate(sde, -ENOSPC); return -ENOSPC; diff --git a/drivers/infiniband/hw/hfi1/sdma.h b/drivers/infiniband/hw/hfi1/sdma.h index 107011d8613b..374c59784950 100644 --- a/drivers/infiniband/hw/hfi1/sdma.h +++ b/drivers/infiniband/hw/hfi1/sdma.h @@ -445,7 +445,7 @@ static inline u16 sdma_descq_freecnt(struct sdma_engine *sde) { return sde->descq_cnt - (sde->descq_tail - - ACCESS_ONCE(sde->descq_head)) - 1; + READ_ONCE(sde->descq_head)) - 1; } static inline u16 sdma_descq_inprocess(struct sdma_engine *sde) diff --git a/drivers/infiniband/hw/hfi1/uc.c b/drivers/infiniband/hw/hfi1/uc.c index 0b646173ca22..9a31c585427f 100644 --- a/drivers/infiniband/hw/hfi1/uc.c +++ b/drivers/infiniband/hw/hfi1/uc.c @@ -80,7 +80,7 @@ int hfi1_make_uc_req(struct rvt_qp *qp, struct hfi1_pkt_state *ps) goto bail; /* We are in the error state, flush the work request. */ smp_read_barrier_depends(); /* see post_one_send() */ - if (qp->s_last == ACCESS_ONCE(qp->s_head)) + if (qp->s_last == READ_ONCE(qp->s_head)) goto bail; /* If DMAs are in progress, we can't flush immediately. */ if (iowait_sdma_pending(&priv->s_iowait)) { @@ -121,7 +121,7 @@ int hfi1_make_uc_req(struct rvt_qp *qp, struct hfi1_pkt_state *ps) goto bail; /* Check if send work queue is empty. */ smp_read_barrier_depends(); /* see post_one_send() */ - if (qp->s_cur == ACCESS_ONCE(qp->s_head)) { + if (qp->s_cur == READ_ONCE(qp->s_head)) { clear_ahg(qp); goto bail; } diff --git a/drivers/infiniband/hw/hfi1/ud.c b/drivers/infiniband/hw/hfi1/ud.c index 2ba74fdd6f15..7fec6b984e3e 100644 --- a/drivers/infiniband/hw/hfi1/ud.c +++ b/drivers/infiniband/hw/hfi1/ud.c @@ -487,7 +487,7 @@ int hfi1_make_ud_req(struct rvt_qp *qp, struct hfi1_pkt_state *ps) goto bail; /* We are in the error state, flush the work request. */ smp_read_barrier_depends(); /* see post_one_send */ - if (qp->s_last == ACCESS_ONCE(qp->s_head)) + if (qp->s_last == READ_ONCE(qp->s_head)) goto bail; /* If DMAs are in progress, we can't flush immediately. */ if (iowait_sdma_pending(&priv->s_iowait)) { @@ -501,7 +501,7 @@ int hfi1_make_ud_req(struct rvt_qp *qp, struct hfi1_pkt_state *ps) /* see post_one_send() */ smp_read_barrier_depends(); - if (qp->s_cur == ACCESS_ONCE(qp->s_head)) + if (qp->s_cur == READ_ONCE(qp->s_head)) goto bail; wqe = rvt_get_swqe_ptr(qp, qp->s_cur); diff --git a/drivers/infiniband/hw/hfi1/user_sdma.c b/drivers/infiniband/hw/hfi1/user_sdma.c index c0c0e0445cbf..8ec6e8a8d6f7 100644 --- a/drivers/infiniband/hw/hfi1/user_sdma.c +++ b/drivers/infiniband/hw/hfi1/user_sdma.c @@ -276,7 +276,7 @@ int hfi1_user_sdma_free_queues(struct hfi1_filedata *fd, /* Wait until all requests have been freed. */ wait_event_interruptible( pq->wait, - (ACCESS_ONCE(pq->state) == SDMA_PKT_Q_INACTIVE)); + (READ_ONCE(pq->state) == SDMA_PKT_Q_INACTIVE)); kfree(pq->reqs); kfree(pq->req_in_use); kmem_cache_destroy(pq->txreq_cache); @@ -591,7 +591,7 @@ int hfi1_user_sdma_process_request(struct hfi1_filedata *fd, if (ret != -EBUSY) { req->status = ret; WRITE_ONCE(req->has_error, 1); - if (ACCESS_ONCE(req->seqcomp) == + if (READ_ONCE(req->seqcomp) == req->seqsubmitted - 1) goto free_req; return ret; @@ -825,7 +825,7 @@ static int user_sdma_send_pkts(struct user_sdma_request *req, unsigned maxpkts) */ if (req->data_len) { iovec = &req->iovs[req->iov_idx]; - if (ACCESS_ONCE(iovec->offset) == iovec->iov.iov_len) { + if (READ_ONCE(iovec->offset) == iovec->iov.iov_len) { if (++req->iov_idx == req->data_iovs) { ret = -EFAULT; goto free_txreq; @@ -1390,7 +1390,7 @@ static void user_sdma_txreq_cb(struct sdma_txreq *txreq, int status) } else { if (status != SDMA_TXREQ_S_OK) req->status = status; - if (req->seqcomp == (ACCESS_ONCE(req->seqsubmitted) - 1) && + if (req->seqcomp == (READ_ONCE(req->seqsubmitted) - 1) && (READ_ONCE(req->done) || READ_ONCE(req->has_error))) { user_sdma_free_request(req, false); diff --git a/drivers/infiniband/hw/qib/qib_ruc.c b/drivers/infiniband/hw/qib/qib_ruc.c index 53efbb0b40c4..9a37e844d4c8 100644 --- a/drivers/infiniband/hw/qib/qib_ruc.c +++ b/drivers/infiniband/hw/qib/qib_ruc.c @@ -368,7 +368,7 @@ static void qib_ruc_loopback(struct rvt_qp *sqp) again: smp_read_barrier_depends(); /* see post_one_send() */ - if (sqp->s_last == ACCESS_ONCE(sqp->s_head)) + if (sqp->s_last == READ_ONCE(sqp->s_head)) goto clr_busy; wqe = rvt_get_swqe_ptr(sqp, sqp->s_last); diff --git a/drivers/infiniband/hw/qib/qib_uc.c b/drivers/infiniband/hw/qib/qib_uc.c index 498e2202e72c..bddcc37ace44 100644 --- a/drivers/infiniband/hw/qib/qib_uc.c +++ b/drivers/infiniband/hw/qib/qib_uc.c @@ -61,7 +61,7 @@ int qib_make_uc_req(struct rvt_qp *qp, unsigned long *flags) goto bail; /* We are in the error state, flush the work request. */ smp_read_barrier_depends(); /* see post_one_send() */ - if (qp->s_last == ACCESS_ONCE(qp->s_head)) + if (qp->s_last == READ_ONCE(qp->s_head)) goto bail; /* If DMAs are in progress, we can't flush immediately. */ if (atomic_read(&priv->s_dma_busy)) { @@ -91,7 +91,7 @@ int qib_make_uc_req(struct rvt_qp *qp, unsigned long *flags) goto bail; /* Check if send work queue is empty. */ smp_read_barrier_depends(); /* see post_one_send() */ - if (qp->s_cur == ACCESS_ONCE(qp->s_head)) + if (qp->s_cur == READ_ONCE(qp->s_head)) goto bail; /* * Start a new request. diff --git a/drivers/infiniband/hw/qib/qib_ud.c b/drivers/infiniband/hw/qib/qib_ud.c index be4907453ac4..15962ed193ce 100644 --- a/drivers/infiniband/hw/qib/qib_ud.c +++ b/drivers/infiniband/hw/qib/qib_ud.c @@ -253,7 +253,7 @@ int qib_make_ud_req(struct rvt_qp *qp, unsigned long *flags) goto bail; /* We are in the error state, flush the work request. */ smp_read_barrier_depends(); /* see post_one_send */ - if (qp->s_last == ACCESS_ONCE(qp->s_head)) + if (qp->s_last == READ_ONCE(qp->s_head)) goto bail; /* If DMAs are in progress, we can't flush immediately. */ if (atomic_read(&priv->s_dma_busy)) { @@ -267,7 +267,7 @@ int qib_make_ud_req(struct rvt_qp *qp, unsigned long *flags) /* see post_one_send() */ smp_read_barrier_depends(); - if (qp->s_cur == ACCESS_ONCE(qp->s_head)) + if (qp->s_cur == READ_ONCE(qp->s_head)) goto bail; wqe = rvt_get_swqe_ptr(qp, qp->s_cur); diff --git a/drivers/infiniband/sw/rdmavt/qp.c b/drivers/infiniband/sw/rdmavt/qp.c index 22df09ae809e..b670cb9d2006 100644 --- a/drivers/infiniband/sw/rdmavt/qp.c +++ b/drivers/infiniband/sw/rdmavt/qp.c @@ -1073,7 +1073,7 @@ int rvt_error_qp(struct rvt_qp *qp, enum ib_wc_status err) rdi->driver_f.notify_error_qp(qp); /* Schedule the sending tasklet to drain the send work queue. */ - if (ACCESS_ONCE(qp->s_last) != qp->s_head) + if (READ_ONCE(qp->s_last) != qp->s_head) rdi->driver_f.schedule_send(qp); rvt_clear_mr_refs(qp, 0); @@ -1686,7 +1686,7 @@ static inline int rvt_qp_is_avail( if (likely(qp->s_avail)) return 0; smp_read_barrier_depends(); /* see rc.c */ - slast = ACCESS_ONCE(qp->s_last); + slast = READ_ONCE(qp->s_last); if (qp->s_head >= slast) avail = qp->s_size - (qp->s_head - slast); else @@ -1917,7 +1917,7 @@ int rvt_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr, * ahead and kick the send engine into gear. Otherwise we will always * just schedule the send to happen later. */ - call_send = qp->s_head == ACCESS_ONCE(qp->s_last) && !wr->next; + call_send = qp->s_head == READ_ONCE(qp->s_last) && !wr->next; for (; wr; wr = wr->next) { err = rvt_post_one_wr(qp, wr, &call_send); diff --git a/drivers/input/misc/regulator-haptic.c b/drivers/input/misc/regulator-haptic.c index 2e8f801932be..a1db1e5040dc 100644 --- a/drivers/input/misc/regulator-haptic.c +++ b/drivers/input/misc/regulator-haptic.c @@ -233,7 +233,7 @@ static int __maybe_unused regulator_haptic_resume(struct device *dev) haptic->suspended = false; - magnitude = ACCESS_ONCE(haptic->magnitude); + magnitude = READ_ONCE(haptic->magnitude); if (magnitude) regulator_haptic_set_voltage(haptic, magnitude); diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c index d216a8f7bc22..33bb074d6941 100644 --- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -347,7 +347,7 @@ static void __cache_size_refresh(void) BUG_ON(!mutex_is_locked(&dm_bufio_clients_lock)); BUG_ON(dm_bufio_client_count < 0); - dm_bufio_cache_size_latch = ACCESS_ONCE(dm_bufio_cache_size); + dm_bufio_cache_size_latch = READ_ONCE(dm_bufio_cache_size); /* * Use default if set to 0 and report the actual cache size used. @@ -960,7 +960,7 @@ static void __get_memory_limit(struct dm_bufio_client *c, { unsigned long buffers; - if (unlikely(ACCESS_ONCE(dm_bufio_cache_size) != dm_bufio_cache_size_latch)) { + if (unlikely(READ_ONCE(dm_bufio_cache_size) != dm_bufio_cache_size_latch)) { if (mutex_trylock(&dm_bufio_clients_lock)) { __cache_size_refresh(); mutex_unlock(&dm_bufio_clients_lock); @@ -1600,7 +1600,7 @@ static bool __try_evict_buffer(struct dm_buffer *b, gfp_t gfp) static unsigned long get_retain_buffers(struct dm_bufio_client *c) { - unsigned long retain_bytes = ACCESS_ONCE(dm_bufio_retain_bytes); + unsigned long retain_bytes = READ_ONCE(dm_bufio_retain_bytes); return retain_bytes >> (c->sectors_per_block_bits + SECTOR_SHIFT); } @@ -1647,7 +1647,7 @@ dm_bufio_shrink_count(struct shrinker *shrink, struct shrink_control *sc) { struct dm_bufio_client *c = container_of(shrink, struct dm_bufio_client, shrinker); - return ACCESS_ONCE(c->n_buffers[LIST_CLEAN]) + ACCESS_ONCE(c->n_buffers[LIST_DIRTY]); + return READ_ONCE(c->n_buffers[LIST_CLEAN]) + READ_ONCE(c->n_buffers[LIST_DIRTY]); } /* @@ -1818,7 +1818,7 @@ EXPORT_SYMBOL_GPL(dm_bufio_set_sector_offset); static unsigned get_max_age_hz(void) { - unsigned max_age = ACCESS_ONCE(dm_bufio_max_age); + unsigned max_age = READ_ONCE(dm_bufio_max_age); if (max_age > UINT_MAX / HZ) max_age = UINT_MAX / HZ; diff --git a/drivers/md/dm-kcopyd.c b/drivers/md/dm-kcopyd.c index cf2c67e35eaf..eb45cc3df31d 100644 --- a/drivers/md/dm-kcopyd.c +++ b/drivers/md/dm-kcopyd.c @@ -107,7 +107,7 @@ static void io_job_start(struct dm_kcopyd_throttle *t) try_again: spin_lock_irq(&throttle_spinlock); - throttle = ACCESS_ONCE(t->throttle); + throttle = READ_ONCE(t->throttle); if (likely(throttle >= 100)) goto skip_limit; @@ -157,7 +157,7 @@ static void io_job_finish(struct dm_kcopyd_throttle *t) t->num_io_jobs--; - if (likely(ACCESS_ONCE(t->throttle) >= 100)) + if (likely(READ_ONCE(t->throttle) >= 100)) goto skip_limit; if (!t->num_io_jobs) { diff --git a/drivers/md/dm-stats.c b/drivers/md/dm-stats.c index 6028d8247f58..a1a5eec783cc 100644 --- a/drivers/md/dm-stats.c +++ b/drivers/md/dm-stats.c @@ -431,7 +431,7 @@ static int dm_stats_delete(struct dm_stats *stats, int id) synchronize_rcu_expedited(); dm_stat_free(&s->rcu_head); } else { - ACCESS_ONCE(dm_stat_need_rcu_barrier) = 1; + WRITE_ONCE(dm_stat_need_rcu_barrier, 1); call_rcu(&s->rcu_head, dm_stat_free); } return 0; @@ -639,12 +639,12 @@ void dm_stats_account_io(struct dm_stats *stats, unsigned long bi_rw, */ last = raw_cpu_ptr(stats->last); stats_aux->merged = - (bi_sector == (ACCESS_ONCE(last->last_sector) && + (bi_sector == (READ_ONCE(last->last_sector) && ((bi_rw == WRITE) == - (ACCESS_ONCE(last->last_rw) == WRITE)) + (READ_ONCE(last->last_rw) == WRITE)) )); - ACCESS_ONCE(last->last_sector) = end_sector; - ACCESS_ONCE(last->last_rw) = bi_rw; + WRITE_ONCE(last->last_sector, end_sector); + WRITE_ONCE(last->last_rw, bi_rw); } rcu_read_lock(); @@ -693,22 +693,22 @@ static void __dm_stat_init_temporary_percpu_totals(struct dm_stat_shared *shared for_each_possible_cpu(cpu) { p = &s->stat_percpu[cpu][x]; - shared->tmp.sectors[READ] += ACCESS_ONCE(p->sectors[READ]); - shared->tmp.sectors[WRITE] += ACCESS_ONCE(p->sectors[WRITE]); - shared->tmp.ios[READ] += ACCESS_ONCE(p->ios[READ]); - shared->tmp.ios[WRITE] += ACCESS_ONCE(p->ios[WRITE]); - shared->tmp.merges[READ] += ACCESS_ONCE(p->merges[READ]); - shared->tmp.merges[WRITE] += ACCESS_ONCE(p->merges[WRITE]); - shared->tmp.ticks[READ] += ACCESS_ONCE(p->ticks[READ]); - shared->tmp.ticks[WRITE] += ACCESS_ONCE(p->ticks[WRITE]); - shared->tmp.io_ticks[READ] += ACCESS_ONCE(p->io_ticks[READ]); - shared->tmp.io_ticks[WRITE] += ACCESS_ONCE(p->io_ticks[WRITE]); - shared->tmp.io_ticks_total += ACCESS_ONCE(p->io_ticks_total); - shared->tmp.time_in_queue += ACCESS_ONCE(p->time_in_queue); + shared->tmp.sectors[READ] += READ_ONCE(p->sectors[READ]); + shared->tmp.sectors[WRITE] += READ_ONCE(p->sectors[WRITE]); + shared->tmp.ios[READ] += READ_ONCE(p->ios[READ]); + shared->tmp.ios[WRITE] += READ_ONCE(p->ios[WRITE]); + shared->tmp.merges[READ] += READ_ONCE(p->merges[READ]); + shared->tmp.merges[WRITE] += READ_ONCE(p->merges[WRITE]); + shared->tmp.ticks[READ] += READ_ONCE(p->ticks[READ]); + shared->tmp.ticks[WRITE] += READ_ONCE(p->ticks[WRITE]); + shared->tmp.io_ticks[READ] += READ_ONCE(p->io_ticks[READ]); + shared->tmp.io_ticks[WRITE] += READ_ONCE(p->io_ticks[WRITE]); + shared->tmp.io_ticks_total += READ_ONCE(p->io_ticks_total); + shared->tmp.time_in_queue += READ_ONCE(p->time_in_queue); if (s->n_histogram_entries) { unsigned i; for (i = 0; i < s->n_histogram_entries + 1; i++) - shared->tmp.histogram[i] += ACCESS_ONCE(p->histogram[i]); + shared->tmp.histogram[i] += READ_ONCE(p->histogram[i]); } } } diff --git a/drivers/md/dm-switch.c b/drivers/md/dm-switch.c index 4c8de1ff78ca..8d0ba879777e 100644 --- a/drivers/md/dm-switch.c +++ b/drivers/md/dm-switch.c @@ -144,7 +144,7 @@ static unsigned switch_region_table_read(struct switch_ctx *sctx, unsigned long switch_get_position(sctx, region_nr, ®ion_index, &bit); - return (ACCESS_ONCE(sctx->region_table[region_index]) >> bit) & + return (READ_ONCE(sctx->region_table[region_index]) >> bit) & ((1 << sctx->region_table_entry_bits) - 1); } diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c index 1e25705209c2..89e5dff9b4cf 100644 --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c @@ -2431,7 +2431,7 @@ static void set_pool_mode(struct pool *pool, enum pool_mode new_mode) struct pool_c *pt = pool->ti->private; bool needs_check = dm_pool_metadata_needs_check(pool->pmd); enum pool_mode old_mode = get_pool_mode(pool); - unsigned long no_space_timeout = ACCESS_ONCE(no_space_timeout_secs) * HZ; + unsigned long no_space_timeout = READ_ONCE(no_space_timeout_secs) * HZ; /* * Never allow the pool to transition to PM_WRITE mode if user diff --git a/drivers/md/dm-verity-target.c b/drivers/md/dm-verity-target.c index bda3caca23ca..fba93237a780 100644 --- a/drivers/md/dm-verity-target.c +++ b/drivers/md/dm-verity-target.c @@ -589,7 +589,7 @@ static void verity_prefetch_io(struct work_struct *work) verity_hash_at_level(v, pw->block, i, &hash_block_start, NULL); verity_hash_at_level(v, pw->block + pw->n_blocks - 1, i, &hash_block_end, NULL); if (!i) { - unsigned cluster = ACCESS_ONCE(dm_verity_prefetch_cluster); + unsigned cluster = READ_ONCE(dm_verity_prefetch_cluster); cluster >>= v->data_dev_block_bits; if (unlikely(!cluster)) diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 4be85324f44d..8aaffa19b29a 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -114,7 +114,7 @@ static unsigned reserved_bio_based_ios = RESERVED_BIO_BASED_IOS; static int __dm_get_module_param_int(int *module_param, int min, int max) { - int param = ACCESS_ONCE(*module_param); + int param = READ_ONCE(*module_param); int modified_param = 0; bool modified = true; @@ -136,7 +136,7 @@ static int __dm_get_module_param_int(int *module_param, int min, int max) unsigned __dm_get_module_param(unsigned *module_param, unsigned def, unsigned max) { - unsigned param = ACCESS_ONCE(*module_param); + unsigned param = READ_ONCE(*module_param); unsigned modified_param = 0; if (!param) diff --git a/drivers/md/md.c b/drivers/md/md.c index 0ff1bbf6c90e..447ddcbc9566 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -2651,7 +2651,7 @@ state_show(struct md_rdev *rdev, char *page) { char *sep = ","; size_t len = 0; - unsigned long flags = ACCESS_ONCE(rdev->flags); + unsigned long flags = READ_ONCE(rdev->flags); if (test_bit(Faulty, &flags) || (!test_bit(ExternalBbl, &flags) && diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 928e24a07133..7d9a50eed9db 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -6072,7 +6072,7 @@ static inline sector_t raid5_sync_request(struct mddev *mddev, sector_t sector_n */ rcu_read_lock(); for (i = 0; i < conf->raid_disks; i++) { - struct md_rdev *rdev = ACCESS_ONCE(conf->disks[i].rdev); + struct md_rdev *rdev = READ_ONCE(conf->disks[i].rdev); if (rdev == NULL || test_bit(Faulty, &rdev->flags)) still_degraded = 1; diff --git a/drivers/misc/mic/scif/scif_rb.c b/drivers/misc/mic/scif/scif_rb.c index 637cc4686742..b665757ca89a 100644 --- a/drivers/misc/mic/scif/scif_rb.c +++ b/drivers/misc/mic/scif/scif_rb.c @@ -138,7 +138,7 @@ void scif_rb_commit(struct scif_rb *rb) * the read barrier in scif_rb_count(..) */ wmb(); - ACCESS_ONCE(*rb->write_ptr) = rb->current_write_offset; + WRITE_ONCE(*rb->write_ptr, rb->current_write_offset); #ifdef CONFIG_INTEL_MIC_CARD /* * X100 Si bug: For the case where a Core is performing an EXT_WR @@ -147,7 +147,7 @@ void scif_rb_commit(struct scif_rb *rb) * This way, if ordering is violated for the Interrupt Message, it will * fall just behind the first Posted associated with the first EXT_WR. */ - ACCESS_ONCE(*rb->write_ptr) = rb->current_write_offset; + WRITE_ONCE(*rb->write_ptr, rb->current_write_offset); #endif } @@ -210,7 +210,7 @@ void scif_rb_update_read_ptr(struct scif_rb *rb) * scif_rb_space(..) */ mb(); - ACCESS_ONCE(*rb->read_ptr) = new_offset; + WRITE_ONCE(*rb->read_ptr, new_offset); #ifdef CONFIG_INTEL_MIC_CARD /* * X100 Si Bug: For the case where a Core is performing an EXT_WR @@ -219,7 +219,7 @@ void scif_rb_update_read_ptr(struct scif_rb *rb) * This way, if ordering is violated for the Interrupt Message, it will * fall just behind the first Posted associated with the first EXT_WR. */ - ACCESS_ONCE(*rb->read_ptr) = new_offset; + WRITE_ONCE(*rb->read_ptr, new_offset); #endif } diff --git a/drivers/misc/mic/scif/scif_rma_list.c b/drivers/misc/mic/scif/scif_rma_list.c index e1ef8daedd5a..a036dbb4101e 100644 --- a/drivers/misc/mic/scif/scif_rma_list.c +++ b/drivers/misc/mic/scif/scif_rma_list.c @@ -277,7 +277,7 @@ int scif_unregister_all_windows(scif_epd_t epd) * Need to restart list traversal if there has been * an asynchronous list entry deletion. */ - if (ACCESS_ONCE(ep->rma_info.async_list_del)) + if (READ_ONCE(ep->rma_info.async_list_del)) goto retry; } mutex_unlock(&ep->rma_info.rma_lock); diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c index c02cc817a490..1ed9529e7bd1 100644 --- a/drivers/net/bonding/bond_alb.c +++ b/drivers/net/bonding/bond_alb.c @@ -1378,7 +1378,7 @@ int bond_tlb_xmit(struct sk_buff *skb, struct net_device *bond_dev) unsigned int count; slaves = rcu_dereference(bond->slave_arr); - count = slaves ? ACCESS_ONCE(slaves->count) : 0; + count = slaves ? READ_ONCE(slaves->count) : 0; if (likely(count)) tx_slave = slaves->arr[hash_index % count]; diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index c99dc59d729b..af51b90cecbb 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -1167,7 +1167,7 @@ static rx_handler_result_t bond_handle_frame(struct sk_buff **pskb) slave = bond_slave_get_rcu(skb->dev); bond = slave->bond; - recv_probe = ACCESS_ONCE(bond->recv_probe); + recv_probe = READ_ONCE(bond->recv_probe); if (recv_probe) { ret = recv_probe(skb, bond, slave); if (ret == RX_HANDLER_CONSUMED) { @@ -3810,7 +3810,7 @@ static int bond_xmit_roundrobin(struct sk_buff *skb, struct net_device *bond_dev else bond_xmit_slave_id(bond, skb, 0); } else { - int slave_cnt = ACCESS_ONCE(bond->slave_cnt); + int slave_cnt = READ_ONCE(bond->slave_cnt); if (likely(slave_cnt)) { slave_id = bond_rr_gen_slave_id(bond); @@ -3972,7 +3972,7 @@ static int bond_3ad_xor_xmit(struct sk_buff *skb, struct net_device *dev) unsigned int count; slaves = rcu_dereference(bond->slave_arr); - count = slaves ? ACCESS_ONCE(slaves->count) : 0; + count = slaves ? READ_ONCE(slaves->count) : 0; if (likely(count)) { slave = slaves->arr[bond_xmit_hash(bond, skb) % count]; bond_dev_queue_xmit(bond, skb, slave->dev); diff --git a/drivers/net/ethernet/chelsio/cxgb4/sge.c b/drivers/net/ethernet/chelsio/cxgb4/sge.c index 4ef68f69b58c..43f52a8fe708 100644 --- a/drivers/net/ethernet/chelsio/cxgb4/sge.c +++ b/drivers/net/ethernet/chelsio/cxgb4/sge.c @@ -405,7 +405,7 @@ void free_tx_desc(struct adapter *adap, struct sge_txq *q, */ static inline int reclaimable(const struct sge_txq *q) { - int hw_cidx = ntohs(ACCESS_ONCE(q->stat->cidx)); + int hw_cidx = ntohs(READ_ONCE(q->stat->cidx)); hw_cidx -= q->cidx; return hw_cidx < 0 ? hw_cidx + q->size : hw_cidx; } @@ -1375,7 +1375,7 @@ out_free: dev_kfree_skb_any(skb); */ static inline void reclaim_completed_tx_imm(struct sge_txq *q) { - int hw_cidx = ntohs(ACCESS_ONCE(q->stat->cidx)); + int hw_cidx = ntohs(READ_ONCE(q->stat->cidx)); int reclaim = hw_cidx - q->cidx; if (reclaim < 0) diff --git a/drivers/net/ethernet/emulex/benet/be_main.c b/drivers/net/ethernet/emulex/benet/be_main.c index 0e3d9f39a807..c6e859a27ee6 100644 --- a/drivers/net/ethernet/emulex/benet/be_main.c +++ b/drivers/net/ethernet/emulex/benet/be_main.c @@ -605,7 +605,7 @@ static void accumulate_16bit_val(u32 *acc, u16 val) if (wrapped) newacc += 65536; - ACCESS_ONCE(*acc) = newacc; + WRITE_ONCE(*acc, newacc); } static void populate_erx_stats(struct be_adapter *adapter, diff --git a/drivers/net/ethernet/hisilicon/hip04_eth.c b/drivers/net/ethernet/hisilicon/hip04_eth.c index 0cec06bec63e..340e28211135 100644 --- a/drivers/net/ethernet/hisilicon/hip04_eth.c +++ b/drivers/net/ethernet/hisilicon/hip04_eth.c @@ -373,7 +373,7 @@ static int hip04_tx_reclaim(struct net_device *ndev, bool force) unsigned int count; smp_rmb(); - count = tx_count(ACCESS_ONCE(priv->tx_head), tx_tail); + count = tx_count(READ_ONCE(priv->tx_head), tx_tail); if (count == 0) goto out; @@ -431,7 +431,7 @@ static int hip04_mac_start_xmit(struct sk_buff *skb, struct net_device *ndev) dma_addr_t phys; smp_rmb(); - count = tx_count(tx_head, ACCESS_ONCE(priv->tx_tail)); + count = tx_count(tx_head, READ_ONCE(priv->tx_tail)); if (count == (TX_DESC_NUM - 1)) { netif_stop_queue(ndev); return NETDEV_TX_BUSY; diff --git a/drivers/net/ethernet/intel/i40e/i40e_debugfs.c b/drivers/net/ethernet/intel/i40e/i40e_debugfs.c index 8f326f87a815..2cb9539c931e 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_debugfs.c +++ b/drivers/net/ethernet/intel/i40e/i40e_debugfs.c @@ -264,7 +264,7 @@ static void i40e_dbg_dump_vsi_seid(struct i40e_pf *pf, int seid) vsi->rx_buf_failed, vsi->rx_page_failed); rcu_read_lock(); for (i = 0; i < vsi->num_queue_pairs; i++) { - struct i40e_ring *rx_ring = ACCESS_ONCE(vsi->rx_rings[i]); + struct i40e_ring *rx_ring = READ_ONCE(vsi->rx_rings[i]); if (!rx_ring) continue; @@ -320,7 +320,7 @@ static void i40e_dbg_dump_vsi_seid(struct i40e_pf *pf, int seid) ITR_IS_DYNAMIC(rx_ring->rx_itr_setting) ? "dynamic" : "fixed"); } for (i = 0; i < vsi->num_queue_pairs; i++) { - struct i40e_ring *tx_ring = ACCESS_ONCE(vsi->tx_rings[i]); + struct i40e_ring *tx_ring = READ_ONCE(vsi->tx_rings[i]); if (!tx_ring) continue; diff --git a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c index 05e89864f781..e9e04a485e0a 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c +++ b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c @@ -1570,7 +1570,7 @@ static void i40e_get_ethtool_stats(struct net_device *netdev, } rcu_read_lock(); for (j = 0; j < vsi->num_queue_pairs; j++) { - tx_ring = ACCESS_ONCE(vsi->tx_rings[j]); + tx_ring = READ_ONCE(vsi->tx_rings[j]); if (!tx_ring) continue; diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c index 6498da8806cb..de1fcac7834d 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_main.c +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c @@ -455,7 +455,7 @@ static void i40e_get_netdev_stats_struct(struct net_device *netdev, u64 bytes, packets; unsigned int start; - tx_ring = ACCESS_ONCE(vsi->tx_rings[i]); + tx_ring = READ_ONCE(vsi->tx_rings[i]); if (!tx_ring) continue; i40e_get_netdev_stats_struct_tx(tx_ring, stats); @@ -791,7 +791,7 @@ static void i40e_update_vsi_stats(struct i40e_vsi *vsi) rcu_read_lock(); for (q = 0; q < vsi->num_queue_pairs; q++) { /* locate Tx ring */ - p = ACCESS_ONCE(vsi->tx_rings[q]); + p = READ_ONCE(vsi->tx_rings[q]); do { start = u64_stats_fetch_begin_irq(&p->syncp); diff --git a/drivers/net/ethernet/intel/i40e/i40e_ptp.c b/drivers/net/ethernet/intel/i40e/i40e_ptp.c index d8456c381c99..97381238eb7c 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_ptp.c +++ b/drivers/net/ethernet/intel/i40e/i40e_ptp.c @@ -130,7 +130,7 @@ static int i40e_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb) } smp_mb(); /* Force any pending update before accessing. */ - adj = ACCESS_ONCE(pf->ptp_base_adj); + adj = READ_ONCE(pf->ptp_base_adj); freq = adj; freq *= ppb; @@ -499,7 +499,7 @@ void i40e_ptp_set_increment(struct i40e_pf *pf) wr32(hw, I40E_PRTTSYN_INC_H, incval >> 32); /* Update the base adjustement value. */ - ACCESS_ONCE(pf->ptp_base_adj) = incval; + WRITE_ONCE(pf->ptp_base_adj, incval); smp_mb(); /* Force the above update. */ } diff --git a/drivers/net/ethernet/intel/igb/e1000_regs.h b/drivers/net/ethernet/intel/igb/e1000_regs.h index 58adbf234e07..31a3f09df9f7 100644 --- a/drivers/net/ethernet/intel/igb/e1000_regs.h +++ b/drivers/net/ethernet/intel/igb/e1000_regs.h @@ -375,7 +375,7 @@ u32 igb_rd32(struct e1000_hw *hw, u32 reg); /* write operations, indexed using DWORDS */ #define wr32(reg, val) \ do { \ - u8 __iomem *hw_addr = ACCESS_ONCE((hw)->hw_addr); \ + u8 __iomem *hw_addr = READ_ONCE((hw)->hw_addr); \ if (!E1000_REMOVED(hw_addr)) \ writel((val), &hw_addr[(reg)]); \ } while (0) diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index fd4a46b03cc8..6bccc2be2b91 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -750,7 +750,7 @@ static void igb_cache_ring_register(struct igb_adapter *adapter) u32 igb_rd32(struct e1000_hw *hw, u32 reg) { struct igb_adapter *igb = container_of(hw, struct igb_adapter, hw); - u8 __iomem *hw_addr = ACCESS_ONCE(hw->hw_addr); + u8 __iomem *hw_addr = READ_ONCE(hw->hw_addr); u32 value = 0; if (E1000_REMOVED(hw_addr)) diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_common.h b/drivers/net/ethernet/intel/ixgbe/ixgbe_common.h index e083732adf64..a01409e2e06c 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_common.h +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_common.h @@ -161,7 +161,7 @@ static inline bool ixgbe_removed(void __iomem *addr) static inline void ixgbe_write_reg(struct ixgbe_hw *hw, u32 reg, u32 value) { - u8 __iomem *reg_addr = ACCESS_ONCE(hw->hw_addr); + u8 __iomem *reg_addr = READ_ONCE(hw->hw_addr); if (ixgbe_removed(reg_addr)) return; @@ -180,7 +180,7 @@ static inline void writeq(u64 val, void __iomem *addr) static inline void ixgbe_write_reg64(struct ixgbe_hw *hw, u32 reg, u64 value) { - u8 __iomem *reg_addr = ACCESS_ONCE(hw->hw_addr); + u8 __iomem *reg_addr = READ_ONCE(hw->hw_addr); if (ixgbe_removed(reg_addr)) return; diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c index 4d76afd13868..2224e691ee07 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c @@ -380,7 +380,7 @@ static void ixgbe_check_remove(struct ixgbe_hw *hw, u32 reg) */ u32 ixgbe_read_reg(struct ixgbe_hw *hw, u32 reg) { - u8 __iomem *reg_addr = ACCESS_ONCE(hw->hw_addr); + u8 __iomem *reg_addr = READ_ONCE(hw->hw_addr); u32 value; if (ixgbe_removed(reg_addr)) @@ -8630,7 +8630,7 @@ static void ixgbe_get_stats64(struct net_device *netdev, rcu_read_lock(); for (i = 0; i < adapter->num_rx_queues; i++) { - struct ixgbe_ring *ring = ACCESS_ONCE(adapter->rx_ring[i]); + struct ixgbe_ring *ring = READ_ONCE(adapter->rx_ring[i]); u64 bytes, packets; unsigned int start; @@ -8646,12 +8646,12 @@ static void ixgbe_get_stats64(struct net_device *netdev, } for (i = 0; i < adapter->num_tx_queues; i++) { - struct ixgbe_ring *ring = ACCESS_ONCE(adapter->tx_ring[i]); + struct ixgbe_ring *ring = READ_ONCE(adapter->tx_ring[i]); ixgbe_get_ring_stats64(stats, ring); } for (i = 0; i < adapter->num_xdp_queues; i++) { - struct ixgbe_ring *ring = ACCESS_ONCE(adapter->xdp_ring[i]); + struct ixgbe_ring *ring = READ_ONCE(adapter->xdp_ring[i]); ixgbe_get_ring_stats64(stats, ring); } diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c index 86d6924a2b71..ae312c45696a 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c @@ -378,7 +378,7 @@ static int ixgbe_ptp_adjfreq_82599(struct ptp_clock_info *ptp, s32 ppb) } smp_mb(); - incval = ACCESS_ONCE(adapter->base_incval); + incval = READ_ONCE(adapter->base_incval); freq = incval; freq *= ppb; @@ -1159,7 +1159,7 @@ void ixgbe_ptp_start_cyclecounter(struct ixgbe_adapter *adapter) } /* update the base incval used to calculate frequency adjustment */ - ACCESS_ONCE(adapter->base_incval) = incval; + WRITE_ONCE(adapter->base_incval, incval); smp_mb(); /* need lock to prevent incorrect read while modifying cyclecounter */ diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c index 032f8ac06357..cacb30682434 100644 --- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c +++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c @@ -164,7 +164,7 @@ static void ixgbevf_check_remove(struct ixgbe_hw *hw, u32 reg) u32 ixgbevf_read_reg(struct ixgbe_hw *hw, u32 reg) { - u8 __iomem *reg_addr = ACCESS_ONCE(hw->hw_addr); + u8 __iomem *reg_addr = READ_ONCE(hw->hw_addr); u32 value; if (IXGBE_REMOVED(reg_addr)) diff --git a/drivers/net/ethernet/intel/ixgbevf/vf.h b/drivers/net/ethernet/intel/ixgbevf/vf.h index 04d8d4ee4f04..c651fefcc3d2 100644 --- a/drivers/net/ethernet/intel/ixgbevf/vf.h +++ b/drivers/net/ethernet/intel/ixgbevf/vf.h @@ -182,7 +182,7 @@ struct ixgbevf_info { static inline void ixgbe_write_reg(struct ixgbe_hw *hw, u32 reg, u32 value) { - u8 __iomem *reg_addr = ACCESS_ONCE(hw->hw_addr); + u8 __iomem *reg_addr = READ_ONCE(hw->hw_addr); if (IXGBE_REMOVED(reg_addr)) return; diff --git a/drivers/net/ethernet/mellanox/mlx4/en_tx.c b/drivers/net/ethernet/mellanox/mlx4/en_tx.c index 8a32a8f7f9c0..3541a7f9d12e 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c @@ -414,8 +414,8 @@ bool mlx4_en_process_tx_cq(struct net_device *dev, index = cons_index & size_mask; cqe = mlx4_en_get_cqe(buf, index, priv->cqe_size) + factor; - last_nr_txbb = ACCESS_ONCE(ring->last_nr_txbb); - ring_cons = ACCESS_ONCE(ring->cons); + last_nr_txbb = READ_ONCE(ring->last_nr_txbb); + ring_cons = READ_ONCE(ring->cons); ring_index = ring_cons & size_mask; stamp_index = ring_index; @@ -479,8 +479,8 @@ bool mlx4_en_process_tx_cq(struct net_device *dev, wmb(); /* we want to dirty this cache line once */ - ACCESS_ONCE(ring->last_nr_txbb) = last_nr_txbb; - ACCESS_ONCE(ring->cons) = ring_cons + txbbs_skipped; + WRITE_ONCE(ring->last_nr_txbb, last_nr_txbb); + WRITE_ONCE(ring->cons, ring_cons + txbbs_skipped); if (cq->type == TX_XDP) return done < budget; @@ -858,7 +858,7 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) goto tx_drop; /* fetch ring->cons far ahead before needing it to avoid stall */ - ring_cons = ACCESS_ONCE(ring->cons); + ring_cons = READ_ONCE(ring->cons); real_size = get_real_size(skb, shinfo, dev, &lso_header_size, &inline_ok, &fragptr); @@ -1066,7 +1066,7 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) */ smp_rmb(); - ring_cons = ACCESS_ONCE(ring->cons); + ring_cons = READ_ONCE(ring->cons); if (unlikely(!mlx4_en_is_tx_ring_full(ring))) { netif_tx_wake_queue(ring->tx_queue); ring->wake_queue++; diff --git a/drivers/net/ethernet/neterion/vxge/vxge-main.c b/drivers/net/ethernet/neterion/vxge/vxge-main.c index 50ea69d88480..5dd5f61e1114 100644 --- a/drivers/net/ethernet/neterion/vxge/vxge-main.c +++ b/drivers/net/ethernet/neterion/vxge/vxge-main.c @@ -2629,7 +2629,7 @@ static void vxge_poll_vp_lockup(unsigned long data) ring = &vdev->vpaths[i].ring; /* Truncated to machine word size number of frames */ - rx_frms = ACCESS_ONCE(ring->stats.rx_frms); + rx_frms = READ_ONCE(ring->stats.rx_frms); /* Did this vpath received any packets */ if (ring->stats.prev_rx_frms == rx_frms) { diff --git a/drivers/net/ethernet/sfc/ef10.c b/drivers/net/ethernet/sfc/ef10.c index 13f72f5b18d2..a95a46bcd339 100644 --- a/drivers/net/ethernet/sfc/ef10.c +++ b/drivers/net/ethernet/sfc/ef10.c @@ -2073,7 +2073,7 @@ static irqreturn_t efx_ef10_msi_interrupt(int irq, void *dev_id) netif_vdbg(efx, intr, efx->net_dev, "IRQ %d on CPU %d\n", irq, raw_smp_processor_id()); - if (likely(ACCESS_ONCE(efx->irq_soft_enabled))) { + if (likely(READ_ONCE(efx->irq_soft_enabled))) { /* Note test interrupts */ if (context->index == efx->irq_level) efx->last_irq_cpu = raw_smp_processor_id(); @@ -2088,7 +2088,7 @@ static irqreturn_t efx_ef10_msi_interrupt(int irq, void *dev_id) static irqreturn_t efx_ef10_legacy_interrupt(int irq, void *dev_id) { struct efx_nic *efx = dev_id; - bool soft_enabled = ACCESS_ONCE(efx->irq_soft_enabled); + bool soft_enabled = READ_ONCE(efx->irq_soft_enabled); struct efx_channel *channel; efx_dword_t reg; u32 queues; @@ -3291,7 +3291,7 @@ static int efx_ef10_handle_rx_event(struct efx_channel *channel, bool rx_cont; u16 flags = 0; - if (unlikely(ACCESS_ONCE(efx->reset_pending))) + if (unlikely(READ_ONCE(efx->reset_pending))) return 0; /* Basic packet information */ @@ -3428,7 +3428,7 @@ efx_ef10_handle_tx_event(struct efx_channel *channel, efx_qword_t *event) unsigned int tx_ev_q_label; int tx_descs = 0; - if (unlikely(ACCESS_ONCE(efx->reset_pending))) + if (unlikely(READ_ONCE(efx->reset_pending))) return 0; if (unlikely(EFX_QWORD_FIELD(*event, ESF_DZ_TX_DROP_EVENT))) @@ -5316,7 +5316,7 @@ static void efx_ef10_filter_remove_old(struct efx_nic *efx) int i; for (i = 0; i < HUNT_FILTER_TBL_ROWS; i++) { - if (ACCESS_ONCE(table->entry[i].spec) & + if (READ_ONCE(table->entry[i].spec) & EFX_EF10_FILTER_FLAG_AUTO_OLD) { rc = efx_ef10_filter_remove_internal(efx, 1U << EFX_FILTER_PRI_AUTO, i, true); diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c index b9cb697b2818..016616a63880 100644 --- a/drivers/net/ethernet/sfc/efx.c +++ b/drivers/net/ethernet/sfc/efx.c @@ -2809,7 +2809,7 @@ static void efx_reset_work(struct work_struct *data) unsigned long pending; enum reset_type method; - pending = ACCESS_ONCE(efx->reset_pending); + pending = READ_ONCE(efx->reset_pending); method = fls(pending) - 1; if (method == RESET_TYPE_MC_BIST) @@ -2874,7 +2874,7 @@ void efx_schedule_reset(struct efx_nic *efx, enum reset_type type) /* If we're not READY then just leave the flags set as the cue * to abort probing or reschedule the reset later. */ - if (ACCESS_ONCE(efx->state) != STATE_READY) + if (READ_ONCE(efx->state) != STATE_READY) return; /* efx_process_channel() will no longer read events once a diff --git a/drivers/net/ethernet/sfc/falcon/efx.c b/drivers/net/ethernet/sfc/falcon/efx.c index 29614da91cbf..7263275fde4a 100644 --- a/drivers/net/ethernet/sfc/falcon/efx.c +++ b/drivers/net/ethernet/sfc/falcon/efx.c @@ -2545,7 +2545,7 @@ static void ef4_reset_work(struct work_struct *data) unsigned long pending; enum reset_type method; - pending = ACCESS_ONCE(efx->reset_pending); + pending = READ_ONCE(efx->reset_pending); method = fls(pending) - 1; if ((method == RESET_TYPE_RECOVER_OR_DISABLE || @@ -2605,7 +2605,7 @@ void ef4_schedule_reset(struct ef4_nic *efx, enum reset_type type) /* If we're not READY then just leave the flags set as the cue * to abort probing or reschedule the reset later. */ - if (ACCESS_ONCE(efx->state) != STATE_READY) + if (READ_ONCE(efx->state) != STATE_READY) return; queue_work(reset_workqueue, &efx->reset_work); diff --git a/drivers/net/ethernet/sfc/falcon/falcon.c b/drivers/net/ethernet/sfc/falcon/falcon.c index 93c713c1f627..cd8bb472d758 100644 --- a/drivers/net/ethernet/sfc/falcon/falcon.c +++ b/drivers/net/ethernet/sfc/falcon/falcon.c @@ -452,7 +452,7 @@ static irqreturn_t falcon_legacy_interrupt_a1(int irq, void *dev_id) "IRQ %d on CPU %d status " EF4_OWORD_FMT "\n", irq, raw_smp_processor_id(), EF4_OWORD_VAL(*int_ker)); - if (!likely(ACCESS_ONCE(efx->irq_soft_enabled))) + if (!likely(READ_ONCE(efx->irq_soft_enabled))) return IRQ_HANDLED; /* Check to see if we have a serious error condition */ @@ -1372,7 +1372,7 @@ static void falcon_reconfigure_mac_wrapper(struct ef4_nic *efx) ef4_oword_t reg; int link_speed, isolate; - isolate = !!ACCESS_ONCE(efx->reset_pending); + isolate = !!READ_ONCE(efx->reset_pending); switch (link_state->speed) { case 10000: link_speed = 3; break; diff --git a/drivers/net/ethernet/sfc/falcon/farch.c b/drivers/net/ethernet/sfc/falcon/farch.c index 05916c710d8c..494884f6af4a 100644 --- a/drivers/net/ethernet/sfc/falcon/farch.c +++ b/drivers/net/ethernet/sfc/falcon/farch.c @@ -834,7 +834,7 @@ ef4_farch_handle_tx_event(struct ef4_channel *channel, ef4_qword_t *event) struct ef4_nic *efx = channel->efx; int tx_packets = 0; - if (unlikely(ACCESS_ONCE(efx->reset_pending))) + if (unlikely(READ_ONCE(efx->reset_pending))) return 0; if (likely(EF4_QWORD_FIELD(*event, FSF_AZ_TX_EV_COMP))) { @@ -990,7 +990,7 @@ ef4_farch_handle_rx_event(struct ef4_channel *channel, const ef4_qword_t *event) struct ef4_rx_queue *rx_queue; struct ef4_nic *efx = channel->efx; - if (unlikely(ACCESS_ONCE(efx->reset_pending))) + if (unlikely(READ_ONCE(efx->reset_pending))) return; rx_ev_cont = EF4_QWORD_FIELD(*event, FSF_AZ_RX_EV_JUMBO_CONT); @@ -1504,7 +1504,7 @@ irqreturn_t ef4_farch_fatal_interrupt(struct ef4_nic *efx) irqreturn_t ef4_farch_legacy_interrupt(int irq, void *dev_id) { struct ef4_nic *efx = dev_id; - bool soft_enabled = ACCESS_ONCE(efx->irq_soft_enabled); + bool soft_enabled = READ_ONCE(efx->irq_soft_enabled); ef4_oword_t *int_ker = efx->irq_status.addr; irqreturn_t result = IRQ_NONE; struct ef4_channel *channel; @@ -1596,7 +1596,7 @@ irqreturn_t ef4_farch_msi_interrupt(int irq, void *dev_id) "IRQ %d on CPU %d status " EF4_OWORD_FMT "\n", irq, raw_smp_processor_id(), EF4_OWORD_VAL(*int_ker)); - if (!likely(ACCESS_ONCE(efx->irq_soft_enabled))) + if (!likely(READ_ONCE(efx->irq_soft_enabled))) return IRQ_HANDLED; /* Handle non-event-queue sources */ diff --git a/drivers/net/ethernet/sfc/falcon/nic.h b/drivers/net/ethernet/sfc/falcon/nic.h index a4c4592f6023..54ca457cdb15 100644 --- a/drivers/net/ethernet/sfc/falcon/nic.h +++ b/drivers/net/ethernet/sfc/falcon/nic.h @@ -83,7 +83,7 @@ static inline struct ef4_tx_queue *ef4_tx_queue_partner(struct ef4_tx_queue *tx_ static inline bool __ef4_nic_tx_is_empty(struct ef4_tx_queue *tx_queue, unsigned int write_count) { - unsigned int empty_read_count = ACCESS_ONCE(tx_queue->empty_read_count); + unsigned int empty_read_count = READ_ONCE(tx_queue->empty_read_count); if (empty_read_count == 0) return false; @@ -464,11 +464,11 @@ irqreturn_t ef4_farch_fatal_interrupt(struct ef4_nic *efx); static inline int ef4_nic_event_test_irq_cpu(struct ef4_channel *channel) { - return ACCESS_ONCE(channel->event_test_cpu); + return READ_ONCE(channel->event_test_cpu); } static inline int ef4_nic_irq_test_irq_cpu(struct ef4_nic *efx) { - return ACCESS_ONCE(efx->last_irq_cpu); + return READ_ONCE(efx->last_irq_cpu); } /* Global Resources */ diff --git a/drivers/net/ethernet/sfc/falcon/tx.c b/drivers/net/ethernet/sfc/falcon/tx.c index 6a75f4140a4b..6486814e97dc 100644 --- a/drivers/net/ethernet/sfc/falcon/tx.c +++ b/drivers/net/ethernet/sfc/falcon/tx.c @@ -134,8 +134,8 @@ static void ef4_tx_maybe_stop_queue(struct ef4_tx_queue *txq1) */ netif_tx_stop_queue(txq1->core_txq); smp_mb(); - txq1->old_read_count = ACCESS_ONCE(txq1->read_count); - txq2->old_read_count = ACCESS_ONCE(txq2->read_count); + txq1->old_read_count = READ_ONCE(txq1->read_count); + txq2->old_read_count = READ_ONCE(txq2->read_count); fill_level = max(txq1->insert_count - txq1->old_read_count, txq2->insert_count - txq2->old_read_count); @@ -524,7 +524,7 @@ void ef4_xmit_done(struct ef4_tx_queue *tx_queue, unsigned int index) /* Check whether the hardware queue is now empty */ if ((int)(tx_queue->read_count - tx_queue->old_write_count) >= 0) { - tx_queue->old_write_count = ACCESS_ONCE(tx_queue->write_count); + tx_queue->old_write_count = READ_ONCE(tx_queue->write_count); if (tx_queue->read_count == tx_queue->old_write_count) { smp_mb(); tx_queue->empty_read_count = diff --git a/drivers/net/ethernet/sfc/farch.c b/drivers/net/ethernet/sfc/farch.c index ba45150f53c7..86454d25a405 100644 --- a/drivers/net/ethernet/sfc/farch.c +++ b/drivers/net/ethernet/sfc/farch.c @@ -827,7 +827,7 @@ efx_farch_handle_tx_event(struct efx_channel *channel, efx_qword_t *event) struct efx_nic *efx = channel->efx; int tx_packets = 0; - if (unlikely(ACCESS_ONCE(efx->reset_pending))) + if (unlikely(READ_ONCE(efx->reset_pending))) return 0; if (likely(EFX_QWORD_FIELD(*event, FSF_AZ_TX_EV_COMP))) { @@ -979,7 +979,7 @@ efx_farch_handle_rx_event(struct efx_channel *channel, const efx_qword_t *event) struct efx_rx_queue *rx_queue; struct efx_nic *efx = channel->efx; - if (unlikely(ACCESS_ONCE(efx->reset_pending))) + if (unlikely(READ_ONCE(efx->reset_pending))) return; rx_ev_cont = EFX_QWORD_FIELD(*event, FSF_AZ_RX_EV_JUMBO_CONT); @@ -1520,7 +1520,7 @@ irqreturn_t efx_farch_fatal_interrupt(struct efx_nic *efx) irqreturn_t efx_farch_legacy_interrupt(int irq, void *dev_id) { struct efx_nic *efx = dev_id; - bool soft_enabled = ACCESS_ONCE(efx->irq_soft_enabled); + bool soft_enabled = READ_ONCE(efx->irq_soft_enabled); efx_oword_t *int_ker = efx->irq_status.addr; irqreturn_t result = IRQ_NONE; struct efx_channel *channel; @@ -1612,7 +1612,7 @@ irqreturn_t efx_farch_msi_interrupt(int irq, void *dev_id) "IRQ %d on CPU %d status " EFX_OWORD_FMT "\n", irq, raw_smp_processor_id(), EFX_OWORD_VAL(*int_ker)); - if (!likely(ACCESS_ONCE(efx->irq_soft_enabled))) + if (!likely(READ_ONCE(efx->irq_soft_enabled))) return IRQ_HANDLED; /* Handle non-event-queue sources */ diff --git a/drivers/net/ethernet/sfc/nic.h b/drivers/net/ethernet/sfc/nic.h index 4d7fb8af880d..7b51b6371724 100644 --- a/drivers/net/ethernet/sfc/nic.h +++ b/drivers/net/ethernet/sfc/nic.h @@ -81,7 +81,7 @@ static struct efx_tx_queue *efx_tx_queue_partner(struct efx_tx_queue *tx_queue) static inline bool __efx_nic_tx_is_empty(struct efx_tx_queue *tx_queue, unsigned int write_count) { - unsigned int empty_read_count = ACCESS_ONCE(tx_queue->empty_read_count); + unsigned int empty_read_count = READ_ONCE(tx_queue->empty_read_count); if (empty_read_count == 0) return false; @@ -617,11 +617,11 @@ irqreturn_t efx_farch_fatal_interrupt(struct efx_nic *efx); static inline int efx_nic_event_test_irq_cpu(struct efx_channel *channel) { - return ACCESS_ONCE(channel->event_test_cpu); + return READ_ONCE(channel->event_test_cpu); } static inline int efx_nic_irq_test_irq_cpu(struct efx_nic *efx) { - return ACCESS_ONCE(efx->last_irq_cpu); + return READ_ONCE(efx->last_irq_cpu); } /* Global Resources */ diff --git a/drivers/net/ethernet/sfc/ptp.c b/drivers/net/ethernet/sfc/ptp.c index 60cdb97f58e2..56c2db398def 100644 --- a/drivers/net/ethernet/sfc/ptp.c +++ b/drivers/net/ethernet/sfc/ptp.c @@ -658,7 +658,7 @@ static void efx_ptp_send_times(struct efx_nic *efx, /* Write host time for specified period or until MC is done */ while ((timespec64_compare(&now.ts_real, &limit) < 0) && - ACCESS_ONCE(*mc_running)) { + READ_ONCE(*mc_running)) { struct timespec64 update_time; unsigned int host_time; @@ -668,7 +668,7 @@ static void efx_ptp_send_times(struct efx_nic *efx, do { pps_get_ts(&now); } while ((timespec64_compare(&now.ts_real, &update_time) < 0) && - ACCESS_ONCE(*mc_running)); + READ_ONCE(*mc_running)); /* Synchronise NIC with single word of time only */ host_time = (now.ts_real.tv_sec << MC_NANOSECOND_BITS | @@ -832,14 +832,14 @@ static int efx_ptp_synchronize(struct efx_nic *efx, unsigned int num_readings) ptp->start.dma_addr); /* Clear flag that signals MC ready */ - ACCESS_ONCE(*start) = 0; + WRITE_ONCE(*start, 0); rc = efx_mcdi_rpc_start(efx, MC_CMD_PTP, synch_buf, MC_CMD_PTP_IN_SYNCHRONIZE_LEN); EFX_WARN_ON_ONCE_PARANOID(rc); /* Wait for start from MCDI (or timeout) */ timeout = jiffies + msecs_to_jiffies(MAX_SYNCHRONISE_WAIT_MS); - while (!ACCESS_ONCE(*start) && (time_before(jiffies, timeout))) { + while (!READ_ONCE(*start) && (time_before(jiffies, timeout))) { udelay(20); /* Usually start MCDI execution quickly */ loops++; } @@ -849,7 +849,7 @@ static int efx_ptp_synchronize(struct efx_nic *efx, unsigned int num_readings) if (!time_before(jiffies, timeout)) ++ptp->sync_timeouts; - if (ACCESS_ONCE(*start)) + if (READ_ONCE(*start)) efx_ptp_send_times(efx, &last_time); /* Collect results */ diff --git a/drivers/net/ethernet/sfc/tx.c b/drivers/net/ethernet/sfc/tx.c index 32bf1fecf864..efb66ea21f27 100644 --- a/drivers/net/ethernet/sfc/tx.c +++ b/drivers/net/ethernet/sfc/tx.c @@ -136,8 +136,8 @@ static void efx_tx_maybe_stop_queue(struct efx_tx_queue *txq1) */ netif_tx_stop_queue(txq1->core_txq); smp_mb(); - txq1->old_read_count = ACCESS_ONCE(txq1->read_count); - txq2->old_read_count = ACCESS_ONCE(txq2->read_count); + txq1->old_read_count = READ_ONCE(txq1->read_count); + txq2->old_read_count = READ_ONCE(txq2->read_count); fill_level = max(txq1->insert_count - txq1->old_read_count, txq2->insert_count - txq2->old_read_count); @@ -752,7 +752,7 @@ void efx_xmit_done(struct efx_tx_queue *tx_queue, unsigned int index) /* Check whether the hardware queue is now empty */ if ((int)(tx_queue->read_count - tx_queue->old_write_count) >= 0) { - tx_queue->old_write_count = ACCESS_ONCE(tx_queue->write_count); + tx_queue->old_write_count = READ_ONCE(tx_queue->write_count); if (tx_queue->read_count == tx_queue->old_write_count) { smp_mb(); tx_queue->empty_read_count = diff --git a/drivers/net/ethernet/sun/niu.c b/drivers/net/ethernet/sun/niu.c index 6a4e8e1bbd90..8ab0fb6892d5 100644 --- a/drivers/net/ethernet/sun/niu.c +++ b/drivers/net/ethernet/sun/niu.c @@ -6245,7 +6245,7 @@ static void niu_get_rx_stats(struct niu *np, pkts = dropped = errors = bytes = 0; - rx_rings = ACCESS_ONCE(np->rx_rings); + rx_rings = READ_ONCE(np->rx_rings); if (!rx_rings) goto no_rings; @@ -6276,7 +6276,7 @@ static void niu_get_tx_stats(struct niu *np, pkts = errors = bytes = 0; - tx_rings = ACCESS_ONCE(np->tx_rings); + tx_rings = READ_ONCE(np->tx_rings); if (!tx_rings) goto no_rings; diff --git a/drivers/net/tap.c b/drivers/net/tap.c index 21b71ae947fd..b55b29b90b88 100644 --- a/drivers/net/tap.c +++ b/drivers/net/tap.c @@ -257,7 +257,7 @@ static struct tap_queue *tap_get_queue(struct tap_dev *tap, * and validate that the result isn't NULL - in case we are * racing against queue removal. */ - int numvtaps = ACCESS_ONCE(tap->numvtaps); + int numvtaps = READ_ONCE(tap->numvtaps); __u32 rxq; if (!numvtaps) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index e21bf90b819f..27cd50c5bc9e 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -469,7 +469,7 @@ static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb, u32 numqueues = 0; rcu_read_lock(); - numqueues = ACCESS_ONCE(tun->numqueues); + numqueues = READ_ONCE(tun->numqueues); txq = __skb_get_hash_symmetric(skb); if (txq) { @@ -864,7 +864,7 @@ static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev) rcu_read_lock(); tfile = rcu_dereference(tun->tfiles[txq]); - numqueues = ACCESS_ONCE(tun->numqueues); + numqueues = READ_ONCE(tun->numqueues); /* Drop packet if interface is not attached */ if (txq >= numqueues) diff --git a/drivers/net/wireless/ath/ath5k/desc.c b/drivers/net/wireless/ath/ath5k/desc.c index bd8d4392d68b..80f75139495f 100644 --- a/drivers/net/wireless/ath/ath5k/desc.c +++ b/drivers/net/wireless/ath/ath5k/desc.c @@ -500,13 +500,13 @@ ath5k_hw_proc_4word_tx_status(struct ath5k_hw *ah, tx_status = &desc->ud.ds_tx5212.tx_stat; - txstat1 = ACCESS_ONCE(tx_status->tx_status_1); + txstat1 = READ_ONCE(tx_status->tx_status_1); /* No frame has been send or error */ if (unlikely(!(txstat1 & AR5K_DESC_TX_STATUS1_DONE))) return -EINPROGRESS; - txstat0 = ACCESS_ONCE(tx_status->tx_status_0); + txstat0 = READ_ONCE(tx_status->tx_status_0); /* * Get descriptor status @@ -700,14 +700,14 @@ ath5k_hw_proc_5212_rx_status(struct ath5k_hw *ah, u32 rxstat0, rxstat1; rx_status = &desc->ud.ds_rx.rx_stat; - rxstat1 = ACCESS_ONCE(rx_status->rx_status_1); + rxstat1 = READ_ONCE(rx_status->rx_status_1); /* No frame received / not ready */ if (unlikely(!(rxstat1 & AR5K_5212_RX_DESC_STATUS1_DONE))) return -EINPROGRESS; memset(rs, 0, sizeof(struct ath5k_rx_status)); - rxstat0 = ACCESS_ONCE(rx_status->rx_status_0); + rxstat0 = READ_ONCE(rx_status->rx_status_0); /* * Frame receive status diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c index 613caca7dc02..785a0f33b7e6 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c @@ -3628,7 +3628,7 @@ static void brcmf_sdio_dataworker(struct work_struct *work) bus->dpc_running = true; wmb(); - while (ACCESS_ONCE(bus->dpc_triggered)) { + while (READ_ONCE(bus->dpc_triggered)) { bus->dpc_triggered = false; brcmf_sdio_dpc(bus); bus->idlecount = 0; diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/ops.c b/drivers/net/wireless/intel/iwlwifi/mvm/ops.c index 231878969332..0f45f34e39d3 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/ops.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/ops.c @@ -1118,7 +1118,7 @@ void iwl_mvm_set_hw_ctkill_state(struct iwl_mvm *mvm, bool state) static bool iwl_mvm_set_hw_rfkill_state(struct iwl_op_mode *op_mode, bool state) { struct iwl_mvm *mvm = IWL_OP_MODE_GET_MVM(op_mode); - bool calibrating = ACCESS_ONCE(mvm->calibrating); + bool calibrating = READ_ONCE(mvm->calibrating); if (state) set_bit(IWL_MVM_STATUS_HW_RFKILL, &mvm->status); diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/tx.c b/drivers/net/wireless/intel/iwlwifi/mvm/tx.c index 6f2e2af23219..6e9d3289b9d0 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/tx.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/tx.c @@ -652,7 +652,7 @@ int iwl_mvm_tx_skb_non_sta(struct iwl_mvm *mvm, struct sk_buff *skb) return -1; } else if (info.control.vif->type == NL80211_IFTYPE_STATION && is_multicast_ether_addr(hdr->addr1)) { - u8 ap_sta_id = ACCESS_ONCE(mvmvif->ap_sta_id); + u8 ap_sta_id = READ_ONCE(mvmvif->ap_sta_id); if (ap_sta_id != IWL_MVM_INVALID_STA) sta_id = ap_sta_id; @@ -700,7 +700,7 @@ static int iwl_mvm_tx_tso(struct iwl_mvm *mvm, struct sk_buff *skb, snap_ip_tcp = 8 + skb_transport_header(skb) - skb_network_header(skb) + tcp_hdrlen(skb); - dbg_max_amsdu_len = ACCESS_ONCE(mvm->max_amsdu_len); + dbg_max_amsdu_len = READ_ONCE(mvm->max_amsdu_len); if (!sta->max_amsdu_len || !ieee80211_is_data_qos(hdr->frame_control) || diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c index a06b6612b658..f25ce3a1ea50 100644 --- a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c +++ b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c @@ -1247,7 +1247,7 @@ static void iwl_pcie_rx_handle(struct iwl_trans *trans, int queue) spin_lock(&rxq->lock); /* uCode's read index (stored in shared DRAM) indicates the last Rx * buffer that the driver may process (last buffer filled by ucode). */ - r = le16_to_cpu(ACCESS_ONCE(rxq->rb_stts->closed_rb_num)) & 0x0FFF; + r = le16_to_cpu(READ_ONCE(rxq->rb_stts->closed_rb_num)) & 0x0FFF; i = rxq->read; /* W/A 9000 device step A0 wrap-around bug */ diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c index 2e3e013ec95a..9ad3f4fe5894 100644 --- a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c +++ b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c @@ -2076,12 +2076,12 @@ static int iwl_trans_pcie_wait_txq_empty(struct iwl_trans *trans, int txq_idx) IWL_DEBUG_TX_QUEUES(trans, "Emptying queue %d...\n", txq_idx); txq = trans_pcie->txq[txq_idx]; - wr_ptr = ACCESS_ONCE(txq->write_ptr); + wr_ptr = READ_ONCE(txq->write_ptr); - while (txq->read_ptr != ACCESS_ONCE(txq->write_ptr) && + while (txq->read_ptr != READ_ONCE(txq->write_ptr) && !time_after(jiffies, now + msecs_to_jiffies(IWL_FLUSH_WAIT_MS))) { - u8 write_ptr = ACCESS_ONCE(txq->write_ptr); + u8 write_ptr = READ_ONCE(txq->write_ptr); if (WARN_ONCE(wr_ptr != write_ptr, "WR pointer moved while flushing %d -> %d\n", @@ -2553,7 +2553,7 @@ static u32 iwl_trans_pcie_dump_rbs(struct iwl_trans *trans, spin_lock(&rxq->lock); - r = le16_to_cpu(ACCESS_ONCE(rxq->rb_stts->closed_rb_num)) & 0x0FFF; + r = le16_to_cpu(READ_ONCE(rxq->rb_stts->closed_rb_num)) & 0x0FFF; for (i = rxq->read, j = 0; i != r && j < allocated_rb_nums; @@ -2814,7 +2814,7 @@ static struct iwl_trans_dump_data /* Dump RBs is supported only for pre-9000 devices (1 queue) */ struct iwl_rxq *rxq = &trans_pcie->rxq[0]; /* RBs */ - num_rbs = le16_to_cpu(ACCESS_ONCE(rxq->rb_stts->closed_rb_num)) + num_rbs = le16_to_cpu(READ_ONCE(rxq->rb_stts->closed_rb_num)) & 0x0FFF; num_rbs = (num_rbs - rxq->read) & RX_QUEUE_MASK; len += num_rbs * (sizeof(*data) + diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c index 6467ffac9811..d2b3d6177a55 100644 --- a/drivers/net/wireless/mac80211_hwsim.c +++ b/drivers/net/wireless/mac80211_hwsim.c @@ -1380,7 +1380,7 @@ static void mac80211_hwsim_tx(struct ieee80211_hw *hw, mac80211_hwsim_monitor_rx(hw, skb, channel); /* wmediumd mode check */ - _portid = ACCESS_ONCE(data->wmediumd); + _portid = READ_ONCE(data->wmediumd); if (_portid) return mac80211_hwsim_tx_frame_nl(hw, skb, _portid); @@ -1477,7 +1477,7 @@ static void mac80211_hwsim_tx_frame(struct ieee80211_hw *hw, struct ieee80211_channel *chan) { struct mac80211_hwsim_data *data = hw->priv; - u32 _pid = ACCESS_ONCE(data->wmediumd); + u32 _pid = READ_ONCE(data->wmediumd); if (ieee80211_hw_check(hw, SUPPORTS_RC_TABLE)) { struct ieee80211_tx_info *txi = IEEE80211_SKB_CB(skb); diff --git a/drivers/scsi/qla2xxx/qla_target.c b/drivers/scsi/qla2xxx/qla_target.c index f05cfc83c9c8..f946bf889015 100644 --- a/drivers/scsi/qla2xxx/qla_target.c +++ b/drivers/scsi/qla2xxx/qla_target.c @@ -996,7 +996,7 @@ static void qlt_free_session_done(struct work_struct *work) if (logout_started) { bool traced = false; - while (!ACCESS_ONCE(sess->logout_completed)) { + while (!READ_ONCE(sess->logout_completed)) { if (!traced) { ql_dbg(ql_dbg_tgt_mgt, vha, 0xf086, "%s: waiting for sess %p logout\n", diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c index 942d094269fb..9469695f5871 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -985,7 +985,7 @@ static unsigned int tcmu_handle_completions(struct tcmu_dev *udev) mb = udev->mb_addr; tcmu_flush_dcache_range(mb, sizeof(*mb)); - while (udev->cmdr_last_cleaned != ACCESS_ONCE(mb->cmd_tail)) { + while (udev->cmdr_last_cleaned != READ_ONCE(mb->cmd_tail)) { struct tcmu_cmd_entry *entry = (void *) mb + CMDR_OFF + udev->cmdr_last_cleaned; struct tcmu_cmd *cmd; diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c index 3e865dbf878c..fbaa2a90d25d 100644 --- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -483,7 +483,7 @@ static ssize_t wdm_read if (rv < 0) return -ERESTARTSYS; - cntr = ACCESS_ONCE(desc->length); + cntr = READ_ONCE(desc->length); if (cntr == 0) { desc->read = 0; retry: diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c index e9326f31db8d..4ae667d8c238 100644 --- a/drivers/usb/core/devio.c +++ b/drivers/usb/core/devio.c @@ -150,7 +150,7 @@ static int usbfs_increase_memory_usage(u64 amount) { u64 lim; - lim = ACCESS_ONCE(usbfs_memory_mb); + lim = READ_ONCE(usbfs_memory_mb); lim <<= 20; atomic64_add(amount, &usbfs_memory_usage); diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c index d930bfda4010..58d59c5f8592 100644 --- a/drivers/usb/core/sysfs.c +++ b/drivers/usb/core/sysfs.c @@ -973,7 +973,7 @@ static ssize_t interface_show(struct device *dev, struct device_attribute *attr, char *string; intf = to_usb_interface(dev); - string = ACCESS_ONCE(intf->cur_altsetting->string); + string = READ_ONCE(intf->cur_altsetting->string); if (!string) return 0; return sprintf(buf, "%s\n", string); @@ -989,7 +989,7 @@ static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, intf = to_usb_interface(dev); udev = interface_to_usbdev(intf); - alt = ACCESS_ONCE(intf->cur_altsetting); + alt = READ_ONCE(intf->cur_altsetting); return sprintf(buf, "usb:v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02X" "ic%02Xisc%02Xip%02Xin%02X\n", diff --git a/drivers/usb/gadget/udc/gr_udc.c b/drivers/usb/gadget/udc/gr_udc.c index 1f9941145746..0b59fa50aa30 100644 --- a/drivers/usb/gadget/udc/gr_udc.c +++ b/drivers/usb/gadget/udc/gr_udc.c @@ -1261,7 +1261,7 @@ static int gr_handle_in_ep(struct gr_ep *ep) if (!req->last_desc) return 0; - if (ACCESS_ONCE(req->last_desc->ctrl) & GR_DESC_IN_CTRL_EN) + if (READ_ONCE(req->last_desc->ctrl) & GR_DESC_IN_CTRL_EN) return 0; /* Not put in hardware buffers yet */ if (gr_read32(&ep->regs->epstat) & (GR_EPSTAT_B1 | GR_EPSTAT_B0)) @@ -1290,7 +1290,7 @@ static int gr_handle_out_ep(struct gr_ep *ep) if (!req->curr_desc) return 0; - ctrl = ACCESS_ONCE(req->curr_desc->ctrl); + ctrl = READ_ONCE(req->curr_desc->ctrl); if (ctrl & GR_DESC_OUT_CTRL_EN) return 0; /* Not received yet */ diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c index 44924824fa41..c86f89babd57 100644 --- a/drivers/usb/host/ohci-hcd.c +++ b/drivers/usb/host/ohci-hcd.c @@ -785,7 +785,7 @@ static void io_watchdog_func(unsigned long _ohci) } /* find the last TD processed by the controller. */ - head = hc32_to_cpu(ohci, ACCESS_ONCE(ed->hwHeadP)) & TD_MASK; + head = hc32_to_cpu(ohci, READ_ONCE(ed->hwHeadP)) & TD_MASK; td_start = td; td_next = list_prepare_entry(td, &ed->td_list, td_list); list_for_each_entry_continue(td_next, &ed->td_list, td_list) { diff --git a/drivers/usb/host/uhci-hcd.h b/drivers/usb/host/uhci-hcd.h index 91b22b2ea3aa..09a2a259941b 100644 --- a/drivers/usb/host/uhci-hcd.h +++ b/drivers/usb/host/uhci-hcd.h @@ -186,7 +186,7 @@ struct uhci_qh { * We need a special accessor for the element pointer because it is * subject to asynchronous updates by the controller. */ -#define qh_element(qh) ACCESS_ONCE((qh)->element) +#define qh_element(qh) READ_ONCE((qh)->element) #define LINK_TO_QH(uhci, qh) (UHCI_PTR_QH((uhci)) | \ cpu_to_hc32((uhci), (qh)->dma_handle)) @@ -274,7 +274,7 @@ struct uhci_td { * subject to asynchronous updates by the controller. */ #define td_status(uhci, td) hc32_to_cpu((uhci), \ - ACCESS_ONCE((td)->status)) + READ_ONCE((td)->status)) #define LINK_TO_TD(uhci, td) (cpu_to_hc32((uhci), (td)->dma_handle)) diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index f5a86f651f38..2bc3705a99bd 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -665,7 +665,7 @@ static int vfio_dev_viable(struct device *dev, void *data) { struct vfio_group *group = data; struct vfio_device *device; - struct device_driver *drv = ACCESS_ONCE(dev->driver); + struct device_driver *drv = READ_ONCE(dev->driver); struct vfio_unbound_dev *unbound; int ret = -EINVAL; diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index 046f6d280af5..35e929f132e8 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -929,7 +929,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) continue; } - tpg = ACCESS_ONCE(vs_tpg[*target]); + tpg = READ_ONCE(vs_tpg[*target]); if (unlikely(!tpg)) { /* Target does not exist, fail the request */ vhost_scsi_send_bad_target(vs, vq, head, out); diff --git a/fs/aio.c b/fs/aio.c index 5a2487217072..e6de7715228c 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -576,7 +576,7 @@ static int kiocb_cancel(struct aio_kiocb *kiocb) * actually has a cancel function, hence the cmpxchg() */ - cancel = ACCESS_ONCE(kiocb->ki_cancel); + cancel = READ_ONCE(kiocb->ki_cancel); do { if (!cancel || cancel == KIOCB_CANCELLED) return -EINVAL; diff --git a/fs/buffer.c b/fs/buffer.c index 170df856bdb9..32ce01f0f95f 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -1692,7 +1692,8 @@ static struct buffer_head *create_page_buffers(struct page *page, struct inode * BUG_ON(!PageLocked(page)); if (!page_has_buffers(page)) - create_empty_buffers(page, 1 << ACCESS_ONCE(inode->i_blkbits), b_state); + create_empty_buffers(page, 1 << READ_ONCE(inode->i_blkbits), + b_state); return page_buffers(page); } diff --git a/fs/crypto/keyinfo.c b/fs/crypto/keyinfo.c index 8e704d12a1cf..0083bd4fcaa5 100644 --- a/fs/crypto/keyinfo.c +++ b/fs/crypto/keyinfo.c @@ -373,7 +373,7 @@ void fscrypt_put_encryption_info(struct inode *inode, struct fscrypt_info *ci) struct fscrypt_info *prev; if (ci == NULL) - ci = ACCESS_ONCE(inode->i_crypt_info); + ci = READ_ONCE(inode->i_crypt_info); if (ci == NULL) return; diff --git a/fs/direct-io.c b/fs/direct-io.c index b53e66d9abd7..98fe1325da9d 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -1152,7 +1152,7 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, get_block_t get_block, dio_iodone_t end_io, dio_submit_t submit_io, int flags) { - unsigned i_blkbits = ACCESS_ONCE(inode->i_blkbits); + unsigned i_blkbits = READ_ONCE(inode->i_blkbits); unsigned blkbits = i_blkbits; unsigned blocksize_mask = (1 << blkbits) - 1; ssize_t retval = -EINVAL; diff --git a/fs/exec.c b/fs/exec.c index 3e14ba25f678..1d6243d9f2b6 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1911,7 +1911,7 @@ void set_dumpable(struct mm_struct *mm, int value) return; do { - old = ACCESS_ONCE(mm->flags); + old = READ_ONCE(mm->flags); new = (old & ~MMF_DUMPABLE_MASK) | value; } while (cmpxchg(&mm->flags, old, new) != old); } diff --git a/fs/fcntl.c b/fs/fcntl.c index 448a1119f0be..57bf2964bb83 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -724,7 +724,7 @@ static void send_sigio_to_task(struct task_struct *p, * F_SETSIG can change ->signum lockless in parallel, make * sure we read it once and use the same value throughout. */ - int signum = ACCESS_ONCE(fown->signum); + int signum = READ_ONCE(fown->signum); if (!sigio_perm(p, fown, signum)) return; diff --git a/fs/fs_pin.c b/fs/fs_pin.c index e747b3d720ee..2d07f292b625 100644 --- a/fs/fs_pin.c +++ b/fs/fs_pin.c @@ -78,7 +78,7 @@ void mnt_pin_kill(struct mount *m) while (1) { struct hlist_node *p; rcu_read_lock(); - p = ACCESS_ONCE(m->mnt_pins.first); + p = READ_ONCE(m->mnt_pins.first); if (!p) { rcu_read_unlock(); break; @@ -92,7 +92,7 @@ void group_pin_kill(struct hlist_head *p) while (1) { struct hlist_node *q; rcu_read_lock(); - q = ACCESS_ONCE(p->first); + q = READ_ONCE(p->first); if (!q) { rcu_read_unlock(); break; diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index 13c65dd2d37d..a42d89371748 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -33,7 +33,7 @@ static struct fuse_dev *fuse_get_dev(struct file *file) * Lockless access is OK, because file->private data is set * once during mount and is valid until the file is released. */ - return ACCESS_ONCE(file->private_data); + return READ_ONCE(file->private_data); } static void fuse_request_init(struct fuse_req *req, struct page **pages, diff --git a/fs/inode.c b/fs/inode.c index d1e35b53bb23..fd401028a309 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -2090,7 +2090,7 @@ void inode_set_flags(struct inode *inode, unsigned int flags, WARN_ON_ONCE(flags & ~mask); do { - old_flags = ACCESS_ONCE(inode->i_flags); + old_flags = READ_ONCE(inode->i_flags); new_flags = (old_flags & ~mask) | flags; } while (unlikely(cmpxchg(&inode->i_flags, old_flags, new_flags) != old_flags)); diff --git a/fs/namei.c b/fs/namei.c index c75ea03ca147..40a0f34bf990 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1209,7 +1209,7 @@ static int follow_managed(struct path *path, struct nameidata *nd) /* Given that we're not holding a lock here, we retain the value in a * local variable for each dentry as we look at it so that we don't see * the components of that value change under us */ - while (managed = ACCESS_ONCE(path->dentry->d_flags), + while (managed = READ_ONCE(path->dentry->d_flags), managed &= DCACHE_MANAGED_DENTRY, unlikely(managed != 0)) { /* Allow the filesystem to manage the transit without i_mutex @@ -1394,7 +1394,7 @@ int follow_down(struct path *path) unsigned managed; int ret; - while (managed = ACCESS_ONCE(path->dentry->d_flags), + while (managed = READ_ONCE(path->dentry->d_flags), unlikely(managed & DCACHE_MANAGED_DENTRY)) { /* Allow the filesystem to manage the transit without i_mutex * being held. diff --git a/fs/namespace.c b/fs/namespace.c index d18deb4c410b..e158ec6b527b 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -353,7 +353,7 @@ int __mnt_want_write(struct vfsmount *m) * incremented count after it has set MNT_WRITE_HOLD. */ smp_mb(); - while (ACCESS_ONCE(mnt->mnt.mnt_flags) & MNT_WRITE_HOLD) + while (READ_ONCE(mnt->mnt.mnt_flags) & MNT_WRITE_HOLD) cpu_relax(); /* * After the slowpath clears MNT_WRITE_HOLD, mnt_is_readonly will diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 5ceaeb1f6fb6..f439f1c45008 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -1081,7 +1081,7 @@ static int nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags) int error; if (flags & LOOKUP_RCU) { - parent = ACCESS_ONCE(dentry->d_parent); + parent = READ_ONCE(dentry->d_parent); dir = d_inode_rcu(parent); if (!dir) return -ECHILD; @@ -1168,7 +1168,7 @@ static int nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags) nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); out_valid: if (flags & LOOKUP_RCU) { - if (parent != ACCESS_ONCE(dentry->d_parent)) + if (parent != READ_ONCE(dentry->d_parent)) return -ECHILD; } else dput(parent); @@ -1582,7 +1582,7 @@ static int nfs4_lookup_revalidate(struct dentry *dentry, unsigned int flags) struct inode *dir; if (flags & LOOKUP_RCU) { - parent = ACCESS_ONCE(dentry->d_parent); + parent = READ_ONCE(dentry->d_parent); dir = d_inode_rcu(parent); if (!dir) return -ECHILD; @@ -1596,7 +1596,7 @@ static int nfs4_lookup_revalidate(struct dentry *dentry, unsigned int flags) ret = -ECHILD; if (!(flags & LOOKUP_RCU)) dput(parent); - else if (parent != ACCESS_ONCE(dentry->d_parent)) + else if (parent != READ_ONCE(dentry->d_parent)) return -ECHILD; goto out; } diff --git a/fs/proc/array.c b/fs/proc/array.c index 77a8eacbe032..375e8bf0dd24 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -453,7 +453,7 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns, cutime = sig->cutime; cstime = sig->cstime; cgtime = sig->cgtime; - rsslim = ACCESS_ONCE(sig->rlim[RLIMIT_RSS].rlim_cur); + rsslim = READ_ONCE(sig->rlim[RLIMIT_RSS].rlim_cur); /* add up live thread stats at the group level */ if (whole) { diff --git a/fs/proc_namespace.c b/fs/proc_namespace.c index 99dff222fe67..03afd5150916 100644 --- a/fs/proc_namespace.c +++ b/fs/proc_namespace.c @@ -27,7 +27,7 @@ static unsigned mounts_poll(struct file *file, poll_table *wait) poll_wait(file, &p->ns->poll, wait); - event = ACCESS_ONCE(ns->event); + event = READ_ONCE(ns->event); if (m->poll_event != event) { m->poll_event = event; res |= POLLERR | POLLPRI; diff --git a/fs/splice.c b/fs/splice.c index f3084cce0ea6..39e2dc01ac12 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -253,7 +253,7 @@ EXPORT_SYMBOL(add_to_pipe); */ int splice_grow_spd(const struct pipe_inode_info *pipe, struct splice_pipe_desc *spd) { - unsigned int buffers = ACCESS_ONCE(pipe->buffers); + unsigned int buffers = READ_ONCE(pipe->buffers); spd->nr_pages_max = buffers; if (buffers <= PIPE_DEF_BUFFERS) diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index 1c713fd5b3e6..f46d133c0949 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -381,7 +381,7 @@ int handle_userfault(struct vm_fault *vmf, unsigned long reason) * in __get_user_pages if userfaultfd_release waits on the * caller of handle_userfault to release the mmap_sem. */ - if (unlikely(ACCESS_ONCE(ctx->released))) { + if (unlikely(READ_ONCE(ctx->released))) { /* * Don't return VM_FAULT_SIGBUS in this case, so a non * cooperative manager can close the uffd after the @@ -477,7 +477,7 @@ int handle_userfault(struct vm_fault *vmf, unsigned long reason) vmf->flags, reason); up_read(&mm->mmap_sem); - if (likely(must_wait && !ACCESS_ONCE(ctx->released) && + if (likely(must_wait && !READ_ONCE(ctx->released) && (return_to_userland ? !signal_pending(current) : !fatal_signal_pending(current)))) { wake_up_poll(&ctx->fd_wqh, POLLIN); @@ -586,7 +586,7 @@ static void userfaultfd_event_wait_completion(struct userfaultfd_ctx *ctx, set_current_state(TASK_KILLABLE); if (ewq->msg.event == 0) break; - if (ACCESS_ONCE(ctx->released) || + if (READ_ONCE(ctx->released) || fatal_signal_pending(current)) { /* * &ewq->wq may be queued in fork_event, but @@ -833,7 +833,7 @@ static int userfaultfd_release(struct inode *inode, struct file *file) struct userfaultfd_wake_range range = { .len = 0, }; unsigned long new_flags; - ACCESS_ONCE(ctx->released) = true; + WRITE_ONCE(ctx->released, true); if (!mmget_not_zero(mm)) goto wakeup; diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h index 51bf7b827387..129975970d99 100644 --- a/fs/xfs/xfs_log_priv.h +++ b/fs/xfs/xfs_log_priv.h @@ -592,9 +592,9 @@ xlog_valid_lsn( * a transiently forward state. Instead, we can see the LSN in a * transiently behind state if we happen to race with a cycle wrap. */ - cur_cycle = ACCESS_ONCE(log->l_curr_cycle); + cur_cycle = READ_ONCE(log->l_curr_cycle); smp_rmb(); - cur_block = ACCESS_ONCE(log->l_curr_block); + cur_block = READ_ONCE(log->l_curr_block); if ((CYCLE_LSN(lsn) > cur_cycle) || (CYCLE_LSN(lsn) == cur_cycle && BLOCK_LSN(lsn) > cur_block)) { diff --git a/include/linux/bitops.h b/include/linux/bitops.h index 8fbe259b197c..0a7ce668f8e0 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -236,7 +236,7 @@ static inline unsigned long __ffs64(u64 word) typeof(*ptr) old, new; \ \ do { \ - old = ACCESS_ONCE(*ptr); \ + old = READ_ONCE(*ptr); \ new = (old & ~mask) | bits; \ } while (cmpxchg(ptr, old, new) != old); \ \ @@ -251,7 +251,7 @@ static inline unsigned long __ffs64(u64 word) typeof(*ptr) old, new; \ \ do { \ - old = ACCESS_ONCE(*ptr); \ + old = READ_ONCE(*ptr); \ new = old & ~clear; \ } while (!(old & test) && \ cmpxchg(ptr, old, new) != old); \ diff --git a/include/linux/dynamic_queue_limits.h b/include/linux/dynamic_queue_limits.h index a4be70398ce1..36dd4ffb5715 100644 --- a/include/linux/dynamic_queue_limits.h +++ b/include/linux/dynamic_queue_limits.h @@ -88,7 +88,7 @@ static inline void dql_queued(struct dql *dql, unsigned int count) /* Returns how many objects can be queued, < 0 indicates over limit. */ static inline int dql_avail(const struct dql *dql) { - return ACCESS_ONCE(dql->adj_limit) - ACCESS_ONCE(dql->num_queued); + return READ_ONCE(dql->adj_limit) - READ_ONCE(dql->num_queued); } /* Record number of completed objects and recalculate the limit. */ diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index 14bc21c2ee7f..785a00ca4628 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -221,7 +221,7 @@ extern struct page *huge_zero_page; static inline bool is_huge_zero_page(struct page *page) { - return ACCESS_ONCE(huge_zero_page) == page; + return READ_ONCE(huge_zero_page) == page; } static inline bool is_huge_zero_pmd(pmd_t pmd) diff --git a/include/linux/if_team.h b/include/linux/if_team.h index 30294603526f..d95cae09dea0 100644 --- a/include/linux/if_team.h +++ b/include/linux/if_team.h @@ -247,7 +247,7 @@ static inline struct team_port *team_get_port_by_index(struct team *team, static inline int team_num_to_port_index(struct team *team, unsigned int num) { - int en_port_count = ACCESS_ONCE(team->en_port_count); + int en_port_count = READ_ONCE(team->en_port_count); if (unlikely(!en_port_count)) return 0; diff --git a/include/linux/llist.h b/include/linux/llist.h index 1957635e6d5f..85abc2915e8d 100644 --- a/include/linux/llist.h +++ b/include/linux/llist.h @@ -198,7 +198,7 @@ static inline void init_llist_head(struct llist_head *list) */ static inline bool llist_empty(const struct llist_head *head) { - return ACCESS_ONCE(head->first) == NULL; + return READ_ONCE(head->first) == NULL; } static inline struct llist_node *llist_next(struct llist_node *node) diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h index 2efb08a60e63..f0fc4700b6ff 100644 --- a/include/linux/pm_runtime.h +++ b/include/linux/pm_runtime.h @@ -105,7 +105,7 @@ static inline bool pm_runtime_callbacks_present(struct device *dev) static inline void pm_runtime_mark_last_busy(struct device *dev) { - ACCESS_ONCE(dev->power.last_busy) = jiffies; + WRITE_ONCE(dev->power.last_busy, jiffies); } static inline bool pm_runtime_is_irq_safe(struct device *dev) diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h index 4f4f786255ef..3fadb6f9982b 100644 --- a/include/net/ip_vs.h +++ b/include/net/ip_vs.h @@ -983,12 +983,12 @@ static inline int sysctl_sync_threshold(struct netns_ipvs *ipvs) static inline int sysctl_sync_period(struct netns_ipvs *ipvs) { - return ACCESS_ONCE(ipvs->sysctl_sync_threshold[1]); + return READ_ONCE(ipvs->sysctl_sync_threshold[1]); } static inline unsigned int sysctl_sync_refresh_period(struct netns_ipvs *ipvs) { - return ACCESS_ONCE(ipvs->sysctl_sync_refresh_period); + return READ_ONCE(ipvs->sysctl_sync_refresh_period); } static inline int sysctl_sync_retries(struct netns_ipvs *ipvs) @@ -1013,7 +1013,7 @@ static inline int sysctl_sloppy_sctp(struct netns_ipvs *ipvs) static inline int sysctl_sync_ports(struct netns_ipvs *ipvs) { - return ACCESS_ONCE(ipvs->sysctl_sync_ports); + return READ_ONCE(ipvs->sysctl_sync_ports); } static inline int sysctl_sync_persist_mode(struct netns_ipvs *ipvs) diff --git a/kernel/acct.c b/kernel/acct.c index 5e72af29ab73..21eedd0dd81a 100644 --- a/kernel/acct.c +++ b/kernel/acct.c @@ -146,7 +146,7 @@ static struct bsd_acct_struct *acct_get(struct pid_namespace *ns) again: smp_rmb(); rcu_read_lock(); - res = to_acct(ACCESS_ONCE(ns->bacct)); + res = to_acct(READ_ONCE(ns->bacct)); if (!res) { rcu_read_unlock(); return NULL; @@ -158,7 +158,7 @@ static struct bsd_acct_struct *acct_get(struct pid_namespace *ns) } rcu_read_unlock(); mutex_lock(&res->lock); - if (res != to_acct(ACCESS_ONCE(ns->bacct))) { + if (res != to_acct(READ_ONCE(ns->bacct))) { mutex_unlock(&res->lock); acct_put(res); goto again; diff --git a/kernel/events/core.c b/kernel/events/core.c index 824a583079a1..8fd2f2d1358a 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -1200,7 +1200,7 @@ perf_event_ctx_lock_nested(struct perf_event *event, int nesting) again: rcu_read_lock(); - ctx = ACCESS_ONCE(event->ctx); + ctx = READ_ONCE(event->ctx); if (!atomic_inc_not_zero(&ctx->refcount)) { rcu_read_unlock(); goto again; @@ -5302,8 +5302,8 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) if (!rb) goto aux_unlock; - aux_offset = ACCESS_ONCE(rb->user_page->aux_offset); - aux_size = ACCESS_ONCE(rb->user_page->aux_size); + aux_offset = READ_ONCE(rb->user_page->aux_offset); + aux_size = READ_ONCE(rb->user_page->aux_size); if (aux_offset < perf_data_size(rb) + PAGE_SIZE) goto aux_unlock; diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c index f684d8e5fa2b..f3e37971c842 100644 --- a/kernel/events/ring_buffer.c +++ b/kernel/events/ring_buffer.c @@ -381,7 +381,7 @@ void *perf_aux_output_begin(struct perf_output_handle *handle, * (B) <-> (C) ordering is still observed by the pmu driver. */ if (!rb->aux_overwrite) { - aux_tail = ACCESS_ONCE(rb->user_page->aux_tail); + aux_tail = READ_ONCE(rb->user_page->aux_tail); handle->wakeup = rb->aux_wakeup + rb->aux_watermark; if (aux_head - aux_tail < perf_aux_size(rb)) handle->size = CIRC_SPACE(aux_head, aux_tail, perf_aux_size(rb)); diff --git a/kernel/exit.c b/kernel/exit.c index f6cad39f35df..6b4298a41167 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1339,7 +1339,7 @@ static int wait_consider_task(struct wait_opts *wo, int ptrace, * Ensure that EXIT_ZOMBIE -> EXIT_DEAD/EXIT_TRACE transition * can't confuse the checks below. */ - int exit_state = ACCESS_ONCE(p->exit_state); + int exit_state = READ_ONCE(p->exit_state); int ret; if (unlikely(exit_state == EXIT_DEAD)) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 81279c6602ff..845f3805c73d 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -2724,7 +2724,7 @@ rb_reserve_next_event(struct ring_buffer *buffer, * if it happened, we have to fail the write. */ barrier(); - if (unlikely(ACCESS_ONCE(cpu_buffer->buffer) != buffer)) { + if (unlikely(READ_ONCE(cpu_buffer->buffer) != buffer)) { local_dec(&cpu_buffer->committing); local_dec(&cpu_buffer->commits); return NULL; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 652c682707cd..9050c8b3ccde 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -1459,7 +1459,7 @@ extern struct trace_event_file *find_event_file(struct trace_array *tr, static inline void *event_file_data(struct file *filp) { - return ACCESS_ONCE(file_inode(filp)->i_private); + return READ_ONCE(file_inode(filp)->i_private); } extern struct mutex event_mutex; diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 49cb41412eec..780262210c9a 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -77,7 +77,7 @@ check_stack(unsigned long ip, unsigned long *stack) { unsigned long this_size, flags; unsigned long *p, *top, *start; static int tracer_frame; - int frame_size = ACCESS_ONCE(tracer_frame); + int frame_size = READ_ONCE(tracer_frame); int i, x; this_size = ((unsigned long)stack) & (THREAD_SIZE-1); diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index c490f1e4313b..d32b45662fb6 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -894,7 +894,7 @@ static bool new_idmap_permitted(const struct file *file, int proc_setgroups_show(struct seq_file *seq, void *v) { struct user_namespace *ns = seq->private; - unsigned long userns_flags = ACCESS_ONCE(ns->flags); + unsigned long userns_flags = READ_ONCE(ns->flags); seq_printf(seq, "%s\n", (userns_flags & USERNS_SETGROUPS_ALLOWED) ? diff --git a/lib/assoc_array.c b/lib/assoc_array.c index 155c55d8db5f..fe7953aead82 100644 --- a/lib/assoc_array.c +++ b/lib/assoc_array.c @@ -39,7 +39,7 @@ static int assoc_array_subtree_iterate(const struct assoc_array_ptr *root, /* Descend through a shortcut */ shortcut = assoc_array_ptr_to_shortcut(cursor); smp_read_barrier_depends(); - cursor = ACCESS_ONCE(shortcut->next_node); + cursor = READ_ONCE(shortcut->next_node); } node = assoc_array_ptr_to_node(cursor); @@ -55,7 +55,7 @@ static int assoc_array_subtree_iterate(const struct assoc_array_ptr *root, */ has_meta = 0; for (; slot < ASSOC_ARRAY_FAN_OUT; slot++) { - ptr = ACCESS_ONCE(node->slots[slot]); + ptr = READ_ONCE(node->slots[slot]); has_meta |= (unsigned long)ptr; if (ptr && assoc_array_ptr_is_leaf(ptr)) { /* We need a barrier between the read of the pointer @@ -89,7 +89,7 @@ static int assoc_array_subtree_iterate(const struct assoc_array_ptr *root, smp_read_barrier_depends(); for (; slot < ASSOC_ARRAY_FAN_OUT; slot++) { - ptr = ACCESS_ONCE(node->slots[slot]); + ptr = READ_ONCE(node->slots[slot]); if (assoc_array_ptr_is_meta(ptr)) { cursor = ptr; goto begin_node; @@ -98,7 +98,7 @@ static int assoc_array_subtree_iterate(const struct assoc_array_ptr *root, finished_node: /* Move up to the parent (may need to skip back over a shortcut) */ - parent = ACCESS_ONCE(node->back_pointer); + parent = READ_ONCE(node->back_pointer); slot = node->parent_slot; if (parent == stop) return 0; @@ -107,7 +107,7 @@ static int assoc_array_subtree_iterate(const struct assoc_array_ptr *root, shortcut = assoc_array_ptr_to_shortcut(parent); smp_read_barrier_depends(); cursor = parent; - parent = ACCESS_ONCE(shortcut->back_pointer); + parent = READ_ONCE(shortcut->back_pointer); slot = shortcut->parent_slot; if (parent == stop) return 0; @@ -147,7 +147,7 @@ int assoc_array_iterate(const struct assoc_array *array, void *iterator_data), void *iterator_data) { - struct assoc_array_ptr *root = ACCESS_ONCE(array->root); + struct assoc_array_ptr *root = READ_ONCE(array->root); if (!root) return 0; @@ -194,7 +194,7 @@ assoc_array_walk(const struct assoc_array *array, pr_devel("-->%s()\n", __func__); - cursor = ACCESS_ONCE(array->root); + cursor = READ_ONCE(array->root); if (!cursor) return assoc_array_walk_tree_empty; @@ -220,7 +220,7 @@ assoc_array_walk(const struct assoc_array *array, slot = segments >> (level & ASSOC_ARRAY_KEY_CHUNK_MASK); slot &= ASSOC_ARRAY_FAN_MASK; - ptr = ACCESS_ONCE(node->slots[slot]); + ptr = READ_ONCE(node->slots[slot]); pr_devel("consider slot %x [ix=%d type=%lu]\n", slot, level, (unsigned long)ptr & 3); @@ -294,7 +294,7 @@ assoc_array_walk(const struct assoc_array *array, } while (sc_level < shortcut->skip_to_level); /* The shortcut matches the leaf's index to this point. */ - cursor = ACCESS_ONCE(shortcut->next_node); + cursor = READ_ONCE(shortcut->next_node); if (((level ^ sc_level) & ~ASSOC_ARRAY_KEY_CHUNK_MASK) != 0) { level = sc_level; goto jumped; @@ -337,7 +337,7 @@ void *assoc_array_find(const struct assoc_array *array, * the terminal node. */ for (slot = 0; slot < ASSOC_ARRAY_FAN_OUT; slot++) { - ptr = ACCESS_ONCE(node->slots[slot]); + ptr = READ_ONCE(node->slots[slot]); if (ptr && assoc_array_ptr_is_leaf(ptr)) { /* We need a barrier between the read of the pointer * and dereferencing the pointer - but only if we are diff --git a/lib/dynamic_queue_limits.c b/lib/dynamic_queue_limits.c index f346715e2255..81770a55cb16 100644 --- a/lib/dynamic_queue_limits.c +++ b/lib/dynamic_queue_limits.c @@ -20,7 +20,7 @@ void dql_completed(struct dql *dql, unsigned int count) unsigned int ovlimit, completed, num_queued; bool all_prev_completed; - num_queued = ACCESS_ONCE(dql->num_queued); + num_queued = READ_ONCE(dql->num_queued); /* Can't complete more than what's in queue */ BUG_ON(count > num_queued - dql->num_completed); diff --git a/lib/llist.c b/lib/llist.c index ae5872b1df0c..7062e931a7bb 100644 --- a/lib/llist.c +++ b/lib/llist.c @@ -41,7 +41,7 @@ bool llist_add_batch(struct llist_node *new_first, struct llist_node *new_last, struct llist_node *first; do { - new_last->next = first = ACCESS_ONCE(head->first); + new_last->next = first = READ_ONCE(head->first); } while (cmpxchg(&head->first, first, new_first) != first); return !first; diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 86c3385b9eb3..1746bae94d41 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -620,8 +620,8 @@ char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_sp rcu_read_lock(); for (i = 0; i < depth; i++, d = p) { - p = ACCESS_ONCE(d->d_parent); - array[i] = ACCESS_ONCE(d->d_name.name); + p = READ_ONCE(d->d_parent); + array[i] = READ_ONCE(d->d_name.name); if (p == d) { if (i) array[i] = ""; diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 269b5df58543..c3bf907a03ee 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2715,7 +2715,7 @@ static unsigned long deferred_split_count(struct shrinker *shrink, struct shrink_control *sc) { struct pglist_data *pgdata = NODE_DATA(sc->nid); - return ACCESS_ONCE(pgdata->split_queue_len); + return READ_ONCE(pgdata->split_queue_len); } static unsigned long deferred_split_scan(struct shrinker *shrink, diff --git a/net/core/dev.c b/net/core/dev.c index 11596a302a26..61559ca3980b 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3725,7 +3725,7 @@ bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index, flow_table = rcu_dereference(rxqueue->rps_flow_table); if (flow_table && flow_id <= flow_table->mask) { rflow = &flow_table->flows[flow_id]; - cpu = ACCESS_ONCE(rflow->cpu); + cpu = READ_ONCE(rflow->cpu); if (rflow->filter == filter_id && cpu < nr_cpu_ids && ((int)(per_cpu(softnet_data, cpu).input_queue_head - rflow->last_qtail) < diff --git a/net/core/pktgen.c b/net/core/pktgen.c index 6e1e10ff433a..3b2034f6d49d 100644 --- a/net/core/pktgen.c +++ b/net/core/pktgen.c @@ -3377,7 +3377,7 @@ static void pktgen_wait_for_skb(struct pktgen_dev *pkt_dev) static void pktgen_xmit(struct pktgen_dev *pkt_dev) { - unsigned int burst = ACCESS_ONCE(pkt_dev->burst); + unsigned int burst = READ_ONCE(pkt_dev->burst); struct net_device *odev = pkt_dev->odev; struct netdev_queue *txq; struct sk_buff *skb; diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c index af74d0433453..f9597ba26599 100644 --- a/net/ipv4/inet_fragment.c +++ b/net/ipv4/inet_fragment.c @@ -164,7 +164,7 @@ static void inet_frag_worker(struct work_struct *work) local_bh_disable(); - for (i = ACCESS_ONCE(f->next_bucket); budget; --budget) { + for (i = READ_ONCE(f->next_bucket); budget; --budget) { evicted += inet_evict_bucket(f, &f->hash[i]); i = (i + 1) & (INETFRAGS_HASHSZ - 1); if (evicted > INETFRAGS_EVICT_MAX) diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 3d9f1c2f81c5..c0864562083b 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -495,7 +495,7 @@ u32 ip_idents_reserve(u32 hash, int segs) { u32 *p_tstamp = ip_tstamps + hash % IP_IDENTS_SZ; atomic_t *p_id = ip_idents + hash % IP_IDENTS_SZ; - u32 old = ACCESS_ONCE(*p_tstamp); + u32 old = READ_ONCE(*p_tstamp); u32 now = (u32)jiffies; u32 new, delta = 0; diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 0bc9e46a5369..48531da1aba6 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1908,7 +1908,7 @@ static bool tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb, if ((skb != tcp_write_queue_tail(sk)) && (limit >= skb->len)) goto send_now; - win_divisor = ACCESS_ONCE(sysctl_tcp_tso_win_divisor); + win_divisor = READ_ONCE(sysctl_tcp_tso_win_divisor); if (win_divisor) { u32 chunk = min(tp->snd_wnd, tp->snd_cwnd * tp->mss_cache); diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index ebfbccae62fd..02ec9a349303 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1853,7 +1853,7 @@ static int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) */ /* if we're overly short, let UDP handle it */ - encap_rcv = ACCESS_ONCE(up->encap_rcv); + encap_rcv = READ_ONCE(up->encap_rcv); if (encap_rcv) { int ret; @@ -2298,7 +2298,7 @@ void udp_destroy_sock(struct sock *sk) unlock_sock_fast(sk, slow); if (static_key_false(&udp_encap_needed) && up->encap_type) { void (*encap_destroy)(struct sock *sk); - encap_destroy = ACCESS_ONCE(up->encap_destroy); + encap_destroy = READ_ONCE(up->encap_destroy); if (encap_destroy) encap_destroy(sk); } diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c index a1c24443cd9e..dab946554157 100644 --- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -490,7 +490,7 @@ ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt, if (!t) goto out; - tproto = ACCESS_ONCE(t->parms.proto); + tproto = READ_ONCE(t->parms.proto); if (tproto != ipproto && tproto != 0) goto out; @@ -899,7 +899,7 @@ static int ipxip6_rcv(struct sk_buff *skb, u8 ipproto, t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr); if (t) { - u8 tproto = ACCESS_ONCE(t->parms.proto); + u8 tproto = READ_ONCE(t->parms.proto); if (tproto != ipproto && tproto != 0) goto drop; @@ -1233,7 +1233,7 @@ ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); - tproto = ACCESS_ONCE(t->parms.proto); + tproto = READ_ONCE(t->parms.proto); if (tproto != IPPROTO_IPIP && tproto != 0) return -1; @@ -1303,7 +1303,7 @@ ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) u8 tproto; int err; - tproto = ACCESS_ONCE(t->parms.proto); + tproto = READ_ONCE(t->parms.proto); if ((tproto != IPPROTO_IPV6 && tproto != 0) || ip6_tnl_addr_conflict(t, ipv6h)) return -1; diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 40d7234c27b9..3f30fa313bf2 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -606,7 +606,7 @@ static int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) */ /* if we're overly short, let UDP handle it */ - encap_rcv = ACCESS_ONCE(up->encap_rcv); + encap_rcv = READ_ONCE(up->encap_rcv); if (encap_rcv) { int ret; @@ -1432,7 +1432,7 @@ void udpv6_destroy_sock(struct sock *sk) if (static_key_false(&udpv6_encap_needed) && up->encap_type) { void (*encap_destroy)(struct sock *sk); - encap_destroy = ACCESS_ONCE(up->encap_destroy); + encap_destroy = READ_ONCE(up->encap_destroy); if (encap_destroy) encap_destroy(sk); } diff --git a/net/llc/llc_input.c b/net/llc/llc_input.c index dd3e83328ad5..82cb93f66b9b 100644 --- a/net/llc/llc_input.c +++ b/net/llc/llc_input.c @@ -193,7 +193,7 @@ int llc_rcv(struct sk_buff *skb, struct net_device *dev, */ rcv = rcu_dereference(sap->rcv_func); dest = llc_pdu_type(skb); - sap_handler = dest ? ACCESS_ONCE(llc_type_handlers[dest - 1]) : NULL; + sap_handler = dest ? READ_ONCE(llc_type_handlers[dest - 1]) : NULL; if (unlikely(!sap_handler)) { if (rcv) rcv(skb, dev, pt, orig_dev); @@ -214,7 +214,7 @@ int llc_rcv(struct sk_buff *skb, struct net_device *dev, kfree_skb(skb); goto out; handle_station: - sta_handler = ACCESS_ONCE(llc_station_handler); + sta_handler = READ_ONCE(llc_station_handler); if (!sta_handler) goto drop; sta_handler(skb); diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c index 69615016d5bf..214d2ba02877 100644 --- a/net/mac80211/sta_info.c +++ b/net/mac80211/sta_info.c @@ -2008,7 +2008,7 @@ static void sta_stats_decode_rate(struct ieee80211_local *local, u16 rate, static int sta_set_rate_info_rx(struct sta_info *sta, struct rate_info *rinfo) { - u16 rate = ACCESS_ONCE(sta_get_last_rx_stats(sta)->last_rate); + u16 rate = READ_ONCE(sta_get_last_rx_stats(sta)->last_rate); if (rate == STA_STATS_RATE_INVALID) return -EINVAL; diff --git a/net/netlabel/netlabel_calipso.c b/net/netlabel/netlabel_calipso.c index d177dd066504..4d748975117d 100644 --- a/net/netlabel/netlabel_calipso.c +++ b/net/netlabel/netlabel_calipso.c @@ -393,7 +393,7 @@ EXPORT_SYMBOL(netlbl_calipso_ops_register); static const struct netlbl_calipso_ops *netlbl_calipso_ops_get(void) { - return ACCESS_ONCE(calipso_ops); + return READ_ONCE(calipso_ops); } /** diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index d396cb61a280..eb866647a27a 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -14201,7 +14201,7 @@ static bool __nl80211_unexpected_frame(struct net_device *dev, u8 cmd, struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy); struct sk_buff *msg; void *hdr; - u32 nlportid = ACCESS_ONCE(wdev->ap_unexpected_nlportid); + u32 nlportid = READ_ONCE(wdev->ap_unexpected_nlportid); if (!nlportid) return false; diff --git a/sound/firewire/amdtp-am824.c b/sound/firewire/amdtp-am824.c index 23ccddb20de1..4210e5c6262e 100644 --- a/sound/firewire/amdtp-am824.c +++ b/sound/firewire/amdtp-am824.c @@ -247,7 +247,7 @@ void amdtp_am824_midi_trigger(struct amdtp_stream *s, unsigned int port, struct amdtp_am824 *p = s->protocol; if (port < p->midi_ports) - ACCESS_ONCE(p->midi[port]) = midi; + WRITE_ONCE(p->midi[port], midi); } EXPORT_SYMBOL_GPL(amdtp_am824_midi_trigger); @@ -336,7 +336,7 @@ static unsigned int process_rx_data_blocks(struct amdtp_stream *s, __be32 *buffe unsigned int data_blocks, unsigned int *syt) { struct amdtp_am824 *p = s->protocol; - struct snd_pcm_substream *pcm = ACCESS_ONCE(s->pcm); + struct snd_pcm_substream *pcm = READ_ONCE(s->pcm); unsigned int pcm_frames; if (pcm) { @@ -357,7 +357,7 @@ static unsigned int process_tx_data_blocks(struct amdtp_stream *s, __be32 *buffe unsigned int data_blocks, unsigned int *syt) { struct amdtp_am824 *p = s->protocol; - struct snd_pcm_substream *pcm = ACCESS_ONCE(s->pcm); + struct snd_pcm_substream *pcm = READ_ONCE(s->pcm); unsigned int pcm_frames; if (pcm) { diff --git a/sound/firewire/amdtp-stream.c b/sound/firewire/amdtp-stream.c index 3fc581a5ad62..4a1dc145327b 100644 --- a/sound/firewire/amdtp-stream.c +++ b/sound/firewire/amdtp-stream.c @@ -376,7 +376,7 @@ static void update_pcm_pointers(struct amdtp_stream *s, ptr = s->pcm_buffer_pointer + frames; if (ptr >= pcm->runtime->buffer_size) ptr -= pcm->runtime->buffer_size; - ACCESS_ONCE(s->pcm_buffer_pointer) = ptr; + WRITE_ONCE(s->pcm_buffer_pointer, ptr); s->pcm_period_pointer += frames; if (s->pcm_period_pointer >= pcm->runtime->period_size) { @@ -388,7 +388,7 @@ static void update_pcm_pointers(struct amdtp_stream *s, static void pcm_period_tasklet(unsigned long data) { struct amdtp_stream *s = (void *)data; - struct snd_pcm_substream *pcm = ACCESS_ONCE(s->pcm); + struct snd_pcm_substream *pcm = READ_ONCE(s->pcm); if (pcm) snd_pcm_period_elapsed(pcm); @@ -453,7 +453,7 @@ static int handle_out_packet(struct amdtp_stream *s, s->data_block_counter = (s->data_block_counter + data_blocks) & 0xff; - buffer[0] = cpu_to_be32(ACCESS_ONCE(s->source_node_id_field) | + buffer[0] = cpu_to_be32(READ_ONCE(s->source_node_id_field) | (s->data_block_quadlets << CIP_DBS_SHIFT) | ((s->sph << CIP_SPH_SHIFT) & CIP_SPH_MASK) | s->data_block_counter); @@ -472,7 +472,7 @@ static int handle_out_packet(struct amdtp_stream *s, if (queue_out_packet(s, payload_length) < 0) return -EIO; - pcm = ACCESS_ONCE(s->pcm); + pcm = READ_ONCE(s->pcm); if (pcm && pcm_frames > 0) update_pcm_pointers(s, pcm, pcm_frames); @@ -504,7 +504,7 @@ static int handle_out_packet_without_header(struct amdtp_stream *s, if (queue_out_packet(s, payload_length) < 0) return -EIO; - pcm = ACCESS_ONCE(s->pcm); + pcm = READ_ONCE(s->pcm); if (pcm && pcm_frames > 0) update_pcm_pointers(s, pcm, pcm_frames); @@ -621,7 +621,7 @@ static int handle_in_packet(struct amdtp_stream *s, if (queue_in_packet(s) < 0) return -EIO; - pcm = ACCESS_ONCE(s->pcm); + pcm = READ_ONCE(s->pcm); if (pcm && pcm_frames > 0) update_pcm_pointers(s, pcm, pcm_frames); @@ -649,7 +649,7 @@ static int handle_in_packet_without_header(struct amdtp_stream *s, if (queue_in_packet(s) < 0) return -EIO; - pcm = ACCESS_ONCE(s->pcm); + pcm = READ_ONCE(s->pcm); if (pcm && pcm_frames > 0) update_pcm_pointers(s, pcm, pcm_frames); @@ -947,7 +947,7 @@ unsigned long amdtp_stream_pcm_pointer(struct amdtp_stream *s) if (!in_interrupt() && amdtp_stream_running(s)) fw_iso_context_flush_completions(s->context); - return ACCESS_ONCE(s->pcm_buffer_pointer); + return READ_ONCE(s->pcm_buffer_pointer); } EXPORT_SYMBOL(amdtp_stream_pcm_pointer); @@ -977,9 +977,8 @@ EXPORT_SYMBOL(amdtp_stream_pcm_ack); void amdtp_stream_update(struct amdtp_stream *s) { /* Precomputing. */ - ACCESS_ONCE(s->source_node_id_field) = - (fw_parent_device(s->unit)->card->node_id << CIP_SID_SHIFT) & - CIP_SID_MASK; + WRITE_ONCE(s->source_node_id_field, + (fw_parent_device(s->unit)->card->node_id << CIP_SID_SHIFT) & CIP_SID_MASK); } EXPORT_SYMBOL(amdtp_stream_update); @@ -1022,7 +1021,7 @@ void amdtp_stream_pcm_abort(struct amdtp_stream *s) { struct snd_pcm_substream *pcm; - pcm = ACCESS_ONCE(s->pcm); + pcm = READ_ONCE(s->pcm); if (pcm) snd_pcm_stop_xrun(pcm); } diff --git a/sound/firewire/amdtp-stream.h b/sound/firewire/amdtp-stream.h index ed6eafd10992..f9abd8b07ce6 100644 --- a/sound/firewire/amdtp-stream.h +++ b/sound/firewire/amdtp-stream.h @@ -220,7 +220,7 @@ static inline bool amdtp_stream_pcm_running(struct amdtp_stream *s) static inline void amdtp_stream_pcm_trigger(struct amdtp_stream *s, struct snd_pcm_substream *pcm) { - ACCESS_ONCE(s->pcm) = pcm; + WRITE_ONCE(s->pcm, pcm); } static inline bool cip_sfc_is_base_44100(enum cip_sfc sfc) diff --git a/sound/firewire/digi00x/amdtp-dot.c b/sound/firewire/digi00x/amdtp-dot.c index 1453c34ce99f..4a884a335248 100644 --- a/sound/firewire/digi00x/amdtp-dot.c +++ b/sound/firewire/digi00x/amdtp-dot.c @@ -327,7 +327,7 @@ void amdtp_dot_midi_trigger(struct amdtp_stream *s, unsigned int port, struct amdtp_dot *p = s->protocol; if (port < MAX_MIDI_PORTS) - ACCESS_ONCE(p->midi[port]) = midi; + WRITE_ONCE(p->midi[port], midi); } static unsigned int process_tx_data_blocks(struct amdtp_stream *s, @@ -338,7 +338,7 @@ static unsigned int process_tx_data_blocks(struct amdtp_stream *s, struct snd_pcm_substream *pcm; unsigned int pcm_frames; - pcm = ACCESS_ONCE(s->pcm); + pcm = READ_ONCE(s->pcm); if (pcm) { read_pcm_s32(s, pcm, buffer, data_blocks); pcm_frames = data_blocks; @@ -359,7 +359,7 @@ static unsigned int process_rx_data_blocks(struct amdtp_stream *s, struct snd_pcm_substream *pcm; unsigned int pcm_frames; - pcm = ACCESS_ONCE(s->pcm); + pcm = READ_ONCE(s->pcm); if (pcm) { write_pcm_s32(s, pcm, buffer, data_blocks); pcm_frames = data_blocks; diff --git a/sound/firewire/fireface/amdtp-ff.c b/sound/firewire/fireface/amdtp-ff.c index 780da9deb2f0..77c7598b61ab 100644 --- a/sound/firewire/fireface/amdtp-ff.c +++ b/sound/firewire/fireface/amdtp-ff.c @@ -108,7 +108,7 @@ static unsigned int process_rx_data_blocks(struct amdtp_stream *s, unsigned int data_blocks, unsigned int *syt) { - struct snd_pcm_substream *pcm = ACCESS_ONCE(s->pcm); + struct snd_pcm_substream *pcm = READ_ONCE(s->pcm); unsigned int pcm_frames; if (pcm) { @@ -127,7 +127,7 @@ static unsigned int process_tx_data_blocks(struct amdtp_stream *s, unsigned int data_blocks, unsigned int *syt) { - struct snd_pcm_substream *pcm = ACCESS_ONCE(s->pcm); + struct snd_pcm_substream *pcm = READ_ONCE(s->pcm); unsigned int pcm_frames; if (pcm) { diff --git a/sound/firewire/fireface/ff-midi.c b/sound/firewire/fireface/ff-midi.c index 949ee56b4e0e..6a49611ee462 100644 --- a/sound/firewire/fireface/ff-midi.c +++ b/sound/firewire/fireface/ff-midi.c @@ -22,7 +22,7 @@ static int midi_playback_open(struct snd_rawmidi_substream *substream) ff->running_status[substream->number] = 0; ff->rx_midi_error[substream->number] = false; - ACCESS_ONCE(ff->rx_midi_substreams[substream->number]) = substream; + WRITE_ONCE(ff->rx_midi_substreams[substream->number], substream); return 0; } @@ -38,7 +38,7 @@ static int midi_playback_close(struct snd_rawmidi_substream *substream) struct snd_ff *ff = substream->rmidi->private_data; cancel_work_sync(&ff->rx_midi_work[substream->number]); - ACCESS_ONCE(ff->rx_midi_substreams[substream->number]) = NULL; + WRITE_ONCE(ff->rx_midi_substreams[substream->number], NULL); return 0; } @@ -52,10 +52,10 @@ static void midi_capture_trigger(struct snd_rawmidi_substream *substream, spin_lock_irqsave(&ff->lock, flags); if (up) - ACCESS_ONCE(ff->tx_midi_substreams[substream->number]) = - substream; + WRITE_ONCE(ff->tx_midi_substreams[substream->number], + substream); else - ACCESS_ONCE(ff->tx_midi_substreams[substream->number]) = NULL; + WRITE_ONCE(ff->tx_midi_substreams[substream->number], NULL); spin_unlock_irqrestore(&ff->lock, flags); } diff --git a/sound/firewire/fireface/ff-transaction.c b/sound/firewire/fireface/ff-transaction.c index dd6c8e839647..332b29f8ed75 100644 --- a/sound/firewire/fireface/ff-transaction.c +++ b/sound/firewire/fireface/ff-transaction.c @@ -12,7 +12,7 @@ static void finish_transmit_midi_msg(struct snd_ff *ff, unsigned int port, int rcode) { struct snd_rawmidi_substream *substream = - ACCESS_ONCE(ff->rx_midi_substreams[port]); + READ_ONCE(ff->rx_midi_substreams[port]); if (rcode_is_permanent_error(rcode)) { ff->rx_midi_error[port] = true; @@ -60,7 +60,7 @@ static inline void fill_midi_buf(struct snd_ff *ff, unsigned int port, static void transmit_midi_msg(struct snd_ff *ff, unsigned int port) { struct snd_rawmidi_substream *substream = - ACCESS_ONCE(ff->rx_midi_substreams[port]); + READ_ONCE(ff->rx_midi_substreams[port]); u8 *buf = (u8 *)ff->msg_buf[port]; int i, len; @@ -159,7 +159,7 @@ static void handle_midi_msg(struct fw_card *card, struct fw_request *request, */ index = (quad >> 8) & 0xff; if (index > 0) { - substream = ACCESS_ONCE(ff->tx_midi_substreams[0]); + substream = READ_ONCE(ff->tx_midi_substreams[0]); if (substream != NULL) { byte = quad & 0xff; snd_rawmidi_receive(substream, &byte, 1); @@ -169,7 +169,7 @@ static void handle_midi_msg(struct fw_card *card, struct fw_request *request, /* Message in second port. */ index = (quad >> 24) & 0xff; if (index > 0) { - substream = ACCESS_ONCE(ff->tx_midi_substreams[1]); + substream = READ_ONCE(ff->tx_midi_substreams[1]); if (substream != NULL) { byte = (quad >> 16) & 0xff; snd_rawmidi_receive(substream, &byte, 1); diff --git a/sound/firewire/isight.c b/sound/firewire/isight.c index 5826aa8362f1..46092fa3ff9b 100644 --- a/sound/firewire/isight.c +++ b/sound/firewire/isight.c @@ -96,7 +96,7 @@ static void isight_update_pointers(struct isight *isight, unsigned int count) ptr += count; if (ptr >= runtime->buffer_size) ptr -= runtime->buffer_size; - ACCESS_ONCE(isight->buffer_pointer) = ptr; + WRITE_ONCE(isight->buffer_pointer, ptr); isight->period_counter += count; if (isight->period_counter >= runtime->period_size) { @@ -111,7 +111,7 @@ static void isight_samples(struct isight *isight, struct snd_pcm_runtime *runtime; unsigned int count1; - if (!ACCESS_ONCE(isight->pcm_running)) + if (!READ_ONCE(isight->pcm_running)) return; runtime = isight->pcm->runtime; @@ -131,7 +131,7 @@ static void isight_samples(struct isight *isight, static void isight_pcm_abort(struct isight *isight) { - if (ACCESS_ONCE(isight->pcm_active)) + if (READ_ONCE(isight->pcm_active)) snd_pcm_stop_xrun(isight->pcm); } @@ -141,7 +141,7 @@ static void isight_dropped_samples(struct isight *isight, unsigned int total) u32 dropped; unsigned int count1; - if (!ACCESS_ONCE(isight->pcm_running)) + if (!READ_ONCE(isight->pcm_running)) return; runtime = isight->pcm->runtime; @@ -293,7 +293,7 @@ static int isight_hw_params(struct snd_pcm_substream *substream, if (err < 0) return err; - ACCESS_ONCE(isight->pcm_active) = true; + WRITE_ONCE(isight->pcm_active, true); return 0; } @@ -331,7 +331,7 @@ static int isight_hw_free(struct snd_pcm_substream *substream) { struct isight *isight = substream->private_data; - ACCESS_ONCE(isight->pcm_active) = false; + WRITE_ONCE(isight->pcm_active, false); mutex_lock(&isight->mutex); isight_stop_streaming(isight); @@ -424,10 +424,10 @@ static int isight_trigger(struct snd_pcm_substream *substream, int cmd) switch (cmd) { case SNDRV_PCM_TRIGGER_START: - ACCESS_ONCE(isight->pcm_running) = true; + WRITE_ONCE(isight->pcm_running, true); break; case SNDRV_PCM_TRIGGER_STOP: - ACCESS_ONCE(isight->pcm_running) = false; + WRITE_ONCE(isight->pcm_running, false); break; default: return -EINVAL; @@ -439,7 +439,7 @@ static snd_pcm_uframes_t isight_pointer(struct snd_pcm_substream *substream) { struct isight *isight = substream->private_data; - return ACCESS_ONCE(isight->buffer_pointer); + return READ_ONCE(isight->buffer_pointer); } static int isight_create_pcm(struct isight *isight) diff --git a/sound/firewire/motu/amdtp-motu.c b/sound/firewire/motu/amdtp-motu.c index 96f0091144bb..f0555a24d90e 100644 --- a/sound/firewire/motu/amdtp-motu.c +++ b/sound/firewire/motu/amdtp-motu.c @@ -310,7 +310,7 @@ static unsigned int process_tx_data_blocks(struct amdtp_stream *s, if (p->midi_ports) read_midi_messages(s, buffer, data_blocks); - pcm = ACCESS_ONCE(s->pcm); + pcm = READ_ONCE(s->pcm); if (data_blocks > 0 && pcm) read_pcm_s32(s, pcm->runtime, buffer, data_blocks); @@ -374,7 +374,7 @@ static unsigned int process_rx_data_blocks(struct amdtp_stream *s, if (p->midi_ports) write_midi_messages(s, buffer, data_blocks); - pcm = ACCESS_ONCE(s->pcm); + pcm = READ_ONCE(s->pcm); if (pcm) write_pcm_s32(s, pcm->runtime, buffer, data_blocks); else diff --git a/sound/firewire/oxfw/oxfw-scs1x.c b/sound/firewire/oxfw/oxfw-scs1x.c index 02d595665898..f33497cdc706 100644 --- a/sound/firewire/oxfw/oxfw-scs1x.c +++ b/sound/firewire/oxfw/oxfw-scs1x.c @@ -112,7 +112,7 @@ static void handle_hss(struct fw_card *card, struct fw_request *request, } if (length >= 1) { - stream = ACCESS_ONCE(scs->input); + stream = READ_ONCE(scs->input); if (stream) midi_input_packet(scs, stream, data, length); } @@ -183,7 +183,7 @@ static void scs_output_work(struct work_struct *work) if (scs->transaction_running) return; - stream = ACCESS_ONCE(scs->output); + stream = READ_ONCE(scs->output); if (!stream || scs->error) { scs->output_idle = true; wake_up(&scs->idle_wait); @@ -291,9 +291,9 @@ static void midi_capture_trigger(struct snd_rawmidi_substream *stream, int up) if (up) { scs->input_escape_count = 0; - ACCESS_ONCE(scs->input) = stream; + WRITE_ONCE(scs->input, stream); } else { - ACCESS_ONCE(scs->input) = NULL; + WRITE_ONCE(scs->input, NULL); } } @@ -319,10 +319,10 @@ static void midi_playback_trigger(struct snd_rawmidi_substream *stream, int up) scs->transaction_bytes = 0; scs->error = false; - ACCESS_ONCE(scs->output) = stream; + WRITE_ONCE(scs->output, stream); schedule_work(&scs->work); } else { - ACCESS_ONCE(scs->output) = NULL; + WRITE_ONCE(scs->output, NULL); } } static void midi_playback_drain(struct snd_rawmidi_substream *stream) diff --git a/sound/firewire/tascam/amdtp-tascam.c b/sound/firewire/tascam/amdtp-tascam.c index 6aff1fc1c72d..ab482423c165 100644 --- a/sound/firewire/tascam/amdtp-tascam.c +++ b/sound/firewire/tascam/amdtp-tascam.c @@ -124,7 +124,7 @@ static unsigned int process_tx_data_blocks(struct amdtp_stream *s, { struct snd_pcm_substream *pcm; - pcm = ACCESS_ONCE(s->pcm); + pcm = READ_ONCE(s->pcm); if (data_blocks > 0 && pcm) read_pcm_s32(s, pcm, buffer, data_blocks); @@ -143,7 +143,7 @@ static unsigned int process_rx_data_blocks(struct amdtp_stream *s, /* This field is not used. */ *syt = 0x0000; - pcm = ACCESS_ONCE(s->pcm); + pcm = READ_ONCE(s->pcm); if (pcm) write_pcm_s32(s, pcm, buffer, data_blocks); else diff --git a/sound/firewire/tascam/tascam-transaction.c b/sound/firewire/tascam/tascam-transaction.c index 8967c52f5032..2ad692dd4b13 100644 --- a/sound/firewire/tascam/tascam-transaction.c +++ b/sound/firewire/tascam/tascam-transaction.c @@ -148,7 +148,7 @@ static void async_midi_port_callback(struct fw_card *card, int rcode, void *callback_data) { struct snd_fw_async_midi_port *port = callback_data; - struct snd_rawmidi_substream *substream = ACCESS_ONCE(port->substream); + struct snd_rawmidi_substream *substream = READ_ONCE(port->substream); /* This port is closed. */ if (substream == NULL) @@ -173,7 +173,7 @@ static void midi_port_work(struct work_struct *work) { struct snd_fw_async_midi_port *port = container_of(work, struct snd_fw_async_midi_port, work); - struct snd_rawmidi_substream *substream = ACCESS_ONCE(port->substream); + struct snd_rawmidi_substream *substream = READ_ONCE(port->substream); int generation; /* Under transacting or error state. */ @@ -282,7 +282,7 @@ static void handle_midi_tx(struct fw_card *card, struct fw_request *request, bytes = 3; } - substream = ACCESS_ONCE(tscm->tx_midi_substreams[port]); + substream = READ_ONCE(tscm->tx_midi_substreams[port]); if (substream != NULL) snd_rawmidi_receive(substream, b + 1, bytes); } diff --git a/sound/soc/xtensa/xtfpga-i2s.c b/sound/soc/xtensa/xtfpga-i2s.c index 8382ffa3bcaf..2472144b329e 100644 --- a/sound/soc/xtensa/xtfpga-i2s.c +++ b/sound/soc/xtensa/xtfpga-i2s.c @@ -165,7 +165,7 @@ static bool xtfpga_pcm_push_tx(struct xtfpga_i2s *i2s) tx_substream = rcu_dereference(i2s->tx_substream); tx_active = tx_substream && snd_pcm_running(tx_substream); if (tx_active) { - unsigned tx_ptr = ACCESS_ONCE(i2s->tx_ptr); + unsigned tx_ptr = READ_ONCE(i2s->tx_ptr); unsigned new_tx_ptr = i2s->tx_fn(i2s, tx_substream->runtime, tx_ptr); @@ -437,7 +437,7 @@ static int xtfpga_pcm_trigger(struct snd_pcm_substream *substream, int cmd) case SNDRV_PCM_TRIGGER_START: case SNDRV_PCM_TRIGGER_RESUME: case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: - ACCESS_ONCE(i2s->tx_ptr) = 0; + WRITE_ONCE(i2s->tx_ptr, 0); rcu_assign_pointer(i2s->tx_substream, substream); xtfpga_pcm_refill_fifo(i2s); break; @@ -459,7 +459,7 @@ static snd_pcm_uframes_t xtfpga_pcm_pointer(struct snd_pcm_substream *substream) { struct snd_pcm_runtime *runtime = substream->runtime; struct xtfpga_i2s *i2s = runtime->private_data; - snd_pcm_uframes_t pos = ACCESS_ONCE(i2s->tx_ptr); + snd_pcm_uframes_t pos = READ_ONCE(i2s->tx_ptr); return pos < runtime->buffer_size ? pos : 0; } diff --git a/sound/usb/bcd2000/bcd2000.c b/sound/usb/bcd2000/bcd2000.c index 7371e5b06035..fc579f330601 100644 --- a/sound/usb/bcd2000/bcd2000.c +++ b/sound/usb/bcd2000/bcd2000.c @@ -108,7 +108,7 @@ static void bcd2000_midi_handle_input(struct bcd2000 *bcd2k, unsigned int payload_length, tocopy; struct snd_rawmidi_substream *midi_receive_substream; - midi_receive_substream = ACCESS_ONCE(bcd2k->midi_receive_substream); + midi_receive_substream = READ_ONCE(bcd2k->midi_receive_substream); if (!midi_receive_substream) return; @@ -139,7 +139,7 @@ static void bcd2000_midi_send(struct bcd2000 *bcd2k) BUILD_BUG_ON(sizeof(device_cmd_prefix) >= BUFSIZE); - midi_out_substream = ACCESS_ONCE(bcd2k->midi_out_substream); + midi_out_substream = READ_ONCE(bcd2k->midi_out_substream); if (!midi_out_substream) return; diff --git a/tools/arch/x86/include/asm/atomic.h b/tools/arch/x86/include/asm/atomic.h index 328eeceec709..96e2d06cb031 100644 --- a/tools/arch/x86/include/asm/atomic.h +++ b/tools/arch/x86/include/asm/atomic.h @@ -24,7 +24,7 @@ */ static inline int atomic_read(const atomic_t *v) { - return ACCESS_ONCE((v)->counter); + return READ_ONCE((v)->counter); } /** diff --git a/tools/include/asm-generic/atomic-gcc.h b/tools/include/asm-generic/atomic-gcc.h index 5e9738f97bf3..97427e700e3b 100644 --- a/tools/include/asm-generic/atomic-gcc.h +++ b/tools/include/asm-generic/atomic-gcc.h @@ -21,7 +21,7 @@ */ static inline int atomic_read(const atomic_t *v) { - return ACCESS_ONCE((v)->counter); + return READ_ONCE((v)->counter); } /** diff --git a/tools/perf/util/auxtrace.h b/tools/perf/util/auxtrace.h index 33b5e6cdf38c..d19e11b68de7 100644 --- a/tools/perf/util/auxtrace.h +++ b/tools/perf/util/auxtrace.h @@ -378,7 +378,7 @@ struct addr_filters { static inline u64 auxtrace_mmap__read_snapshot_head(struct auxtrace_mmap *mm) { struct perf_event_mmap_page *pc = mm->userpg; - u64 head = ACCESS_ONCE(pc->aux_head); + u64 head = READ_ONCE(pc->aux_head); /* Ensure all reads are done after we read the head */ rmb(); @@ -389,7 +389,7 @@ static inline u64 auxtrace_mmap__read_head(struct auxtrace_mmap *mm) { struct perf_event_mmap_page *pc = mm->userpg; #if BITS_PER_LONG == 64 || !defined(HAVE_SYNC_COMPARE_AND_SWAP_SUPPORT) - u64 head = ACCESS_ONCE(pc->aux_head); + u64 head = READ_ONCE(pc->aux_head); #else u64 head = __sync_val_compare_and_swap(&pc->aux_head, 0, 0); #endif diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h index 47b5e7dbcb18..aae9645c7122 100644 --- a/tools/perf/util/session.h +++ b/tools/perf/util/session.h @@ -113,7 +113,7 @@ int __perf_session__set_tracepoints_handlers(struct perf_session *session, extern volatile int session_done; -#define session_done() ACCESS_ONCE(session_done) +#define session_done() READ_ONCE(session_done) int perf_session__deliver_synth_event(struct perf_session *session, union perf_event *event, diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 9deb5a245b83..ce507ae1d4f5 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2302,7 +2302,7 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode) continue; } else if (pass && i > last_boosted_vcpu) break; - if (!ACCESS_ONCE(vcpu->preempted)) + if (!READ_ONCE(vcpu->preempted)) continue; if (vcpu == me) continue; From 65e53aab6d54385dea799356defcbdcc456fb1a7 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 25 Oct 2017 17:55:57 +0900 Subject: [PATCH 44/70] block: Use DECLARE_COMPLETION_ONSTACK() in submit_bio_wait() Simplify the code by getting rid of the submit_bio_ret structure. (This also helps address a lockdep false positive.) Signed-off-by: Christoph Hellwig Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: amir73il@gmail.com Cc: axboe@kernel.dk Cc: darrick.wong@oracle.com Cc: david@fromorbit.com Cc: hch@infradead.org Cc: idryomov@gmail.com Cc: johan@kernel.org Cc: johannes.berg@intel.com Cc: kernel-team@lge.com Cc: linux-block@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-xfs@vger.kernel.org Cc: oleg@redhat.com Cc: tj@kernel.org Link: http://lkml.kernel.org/r/1508921765-15396-2-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar --- block/bio.c | 19 +++++-------------- 1 file changed, 5 insertions(+), 14 deletions(-) diff --git a/block/bio.c b/block/bio.c index 101c2a9b5481..5e901bfc0576 100644 --- a/block/bio.c +++ b/block/bio.c @@ -917,17 +917,9 @@ int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) } EXPORT_SYMBOL_GPL(bio_iov_iter_get_pages); -struct submit_bio_ret { - struct completion event; - int error; -}; - static void submit_bio_wait_endio(struct bio *bio) { - struct submit_bio_ret *ret = bio->bi_private; - - ret->error = blk_status_to_errno(bio->bi_status); - complete(&ret->event); + complete(bio->bi_private); } /** @@ -943,16 +935,15 @@ static void submit_bio_wait_endio(struct bio *bio) */ int submit_bio_wait(struct bio *bio) { - struct submit_bio_ret ret; + DECLARE_COMPLETION_ONSTACK(done); - init_completion(&ret.event); - bio->bi_private = &ret; + bio->bi_private = &done; bio->bi_end_io = submit_bio_wait_endio; bio->bi_opf |= REQ_SYNC; submit_bio(bio); - wait_for_completion_io(&ret.event); + wait_for_completion_io(&done); - return ret.error; + return blk_status_to_errno(bio->bi_status); } EXPORT_SYMBOL(submit_bio_wait); From 6f0397d7e100f3b3978d6ebb6b2dea29ee7c4a95 Mon Sep 17 00:00:00 2001 From: Byungchul Park Date: Wed, 25 Oct 2017 17:55:58 +0900 Subject: [PATCH 45/70] locking/lockdep: Provide empty lockdep_map structure for !CONFIG_LOCKDEP After this patch the lockdep_map structure takes no space if lockdep is disabled, reducing the number of #ifdefs in unrelated kernel code. Signed-off-by: Byungchul Park Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: amir73il@gmail.com Cc: axboe@kernel.dk Cc: darrick.wong@oracle.com Cc: david@fromorbit.com Cc: hch@infradead.org Cc: idryomov@gmail.com Cc: johan@kernel.org Cc: johannes.berg@intel.com Cc: kernel-team@lge.com Cc: linux-block@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-xfs@vger.kernel.org Cc: oleg@redhat.com Cc: tj@kernel.org Link: http://lkml.kernel.org/r/1508921765-15396-3-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar --- include/linux/lockdep.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index bfa8e0b0d6f1..b6662d05bcda 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -527,6 +527,11 @@ static inline void lockdep_on(void) */ struct lock_class_key { }; +/* + * The lockdep_map takes no space if lockdep is disabled: + */ +struct lockdep_map { }; + #define lockdep_depth(tsk) (0) #define lockdep_is_held_type(l, r) (1) From 24208435e343679b21502fb90786084dfaf15369 Mon Sep 17 00:00:00 2001 From: Byungchul Park Date: Wed, 25 Oct 2017 17:55:59 +0900 Subject: [PATCH 46/70] locking/lockdep, sched/completions: Change the prefix of lock name for completion variables CONFIG_LOCKDEP_COMPLETIONS uses "(complete)" as a prefix of lock name for completion variable. However, what we should use here is a noun - so use "(completion)" instead. Suggested-by: Ingo Molnar Signed-off-by: Byungchul Park Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: amir73il@gmail.com Cc: axboe@kernel.dk Cc: darrick.wong@oracle.com Cc: david@fromorbit.com Cc: hch@infradead.org Cc: idryomov@gmail.com Cc: johan@kernel.org Cc: johannes.berg@intel.com Cc: kernel-team@lge.com Cc: linux-block@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-xfs@vger.kernel.org Cc: oleg@redhat.com Cc: tj@kernel.org Link: http://lkml.kernel.org/r/1508921765-15396-4-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar --- include/linux/completion.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/linux/completion.h b/include/linux/completion.h index cae5400022a3..91218036b1c8 100644 --- a/include/linux/completion.h +++ b/include/linux/completion.h @@ -53,7 +53,7 @@ static inline void complete_release_commit(struct completion *x) do { \ static struct lock_class_key __key; \ lockdep_init_map_crosslock((struct lockdep_map *)&(x)->map, \ - "(complete)" #x, \ + "(completion)" #x, \ &__key, 0); \ __init_completion(x); \ } while (0) @@ -67,7 +67,7 @@ static inline void complete_release_commit(struct completion *x) {} #ifdef CONFIG_LOCKDEP_COMPLETIONS #define COMPLETION_INITIALIZER(work) \ { 0, __WAIT_QUEUE_HEAD_INITIALIZER((work).wait), \ - STATIC_CROSS_LOCKDEP_MAP_INIT("(complete)" #work, &(work)) } + STATIC_CROSS_LOCKDEP_MAP_INIT("(completion)" #work, &(work)) } #else #define COMPLETION_INITIALIZER(work) \ { 0, __WAIT_QUEUE_HEAD_INITIALIZER((work).wait) } From d141babe4244945f1d001118578e0eb3ce12729d Mon Sep 17 00:00:00 2001 From: Byungchul Park Date: Wed, 25 Oct 2017 17:56:00 +0900 Subject: [PATCH 47/70] locking/lockdep: Add a boot parameter allowing unwind in cross-release and disable it by default Johan Hovold reported a heavy performance regression caused by lockdep cross-release: > Boot time (from "Linux version" to login prompt) had in fact doubled > since 4.13 where it took 17 seconds (with my current config) compared to > the 35 seconds I now see with 4.14-rc4. > > I quick bisect pointed to lockdep and specifically the following commit: > > 28a903f63ec0 ("locking/lockdep: Handle non(or multi)-acquisition > of a crosslock") > > which I've verified is the commit which doubled the boot time (compared > to 28a903f63ec0^) (added by lockdep crossrelease series [1]). Currently cross-release performs unwind on every acquisition, but that is very expensive. This patch makes unwind optional and disables it by default and only records acquire_ip. Full stack traces are sometimes required for full analysis, in which case a boot paramter, crossrelease_fullstack, can be specified. On my qemu Ubuntu machine (x86_64, 4 cores, 512M), the regression was fixed. We measure boot times with 'perf stat --null --repeat 10 $QEMU', where $QEMU launches a kernel with init=/bin/true: 1. No lockdep enabled: Performance counter stats for 'qemu_booting_time.sh bzImage' (10 runs): 2.756558155 seconds time elapsed ( +- 0.09% ) 2. Lockdep enabled: Performance counter stats for 'qemu_booting_time.sh bzImage' (10 runs): 2.968710420 seconds time elapsed ( +- 0.12% ) 3. Lockdep enabled + cross-release enabled: Performance counter stats for 'qemu_booting_time.sh bzImage' (10 runs): 3.153839636 seconds time elapsed ( +- 0.31% ) 4. Lockdep enabled + cross-release enabled + this patch applied: Performance counter stats for 'qemu_booting_time.sh bzImage' (10 runs): 2.963669551 seconds time elapsed ( +- 0.11% ) I.e. lockdep cross-release performance is now indistinguishable from vanilla lockdep. Bisected-by: Johan Hovold Analyzed-by: Thomas Gleixner Suggested-by: Thomas Gleixner Reported-by: Johan Hovold Signed-off-by: Byungchul Park Cc: Linus Torvalds Cc: Peter Zijlstra Cc: amir73il@gmail.com Cc: axboe@kernel.dk Cc: darrick.wong@oracle.com Cc: david@fromorbit.com Cc: hch@infradead.org Cc: idryomov@gmail.com Cc: johannes.berg@intel.com Cc: kernel-team@lge.com Cc: linux-block@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-xfs@vger.kernel.org Cc: oleg@redhat.com Cc: tj@kernel.org Link: http://lkml.kernel.org/r/1508921765-15396-5-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar --- .../admin-guide/kernel-parameters.txt | 3 +++ kernel/locking/lockdep.c | 19 +++++++++++++++++-- 2 files changed, 20 insertions(+), 2 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 05496622b4ef..f20ed5e0a720 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -709,6 +709,9 @@ It will be ignored when crashkernel=X,high is not used or memory reserved is below 4G. + crossrelease_fullstack + [KNL] Allow to record full stack trace in cross-release + cryptomgr.notests [KNL] Disable crypto self-tests diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index e36e652d996f..160b5d6df7cb 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -76,6 +76,15 @@ module_param(lock_stat, int, 0644); #define lock_stat 0 #endif +static int crossrelease_fullstack; +static int __init allow_crossrelease_fullstack(char *str) +{ + crossrelease_fullstack = 1; + return 0; +} + +early_param("crossrelease_fullstack", allow_crossrelease_fullstack); + /* * lockdep_lock: protects the lockdep graph, the hashes and the * class/list/hash allocators. @@ -4863,8 +4872,14 @@ static void add_xhlock(struct held_lock *hlock) xhlock->trace.nr_entries = 0; xhlock->trace.max_entries = MAX_XHLOCK_TRACE_ENTRIES; xhlock->trace.entries = xhlock->trace_entries; - xhlock->trace.skip = 3; - save_stack_trace(&xhlock->trace); + + if (crossrelease_fullstack) { + xhlock->trace.skip = 3; + save_stack_trace(&xhlock->trace); + } else { + xhlock->trace.nr_entries = 1; + xhlock->trace.entries[0] = hlock->acquire_ip; + } } static inline int same_context_xhlock(struct hist_lock *xhlock) From 2dcd5adfb7401b762ddbe4b86dcacc2f3de6b97b Mon Sep 17 00:00:00 2001 From: Byungchul Park Date: Wed, 25 Oct 2017 17:56:01 +0900 Subject: [PATCH 48/70] locking/lockdep: Remove the BROKEN flag from CONFIG_LOCKDEP_CROSSRELEASE and CONFIG_LOCKDEP_COMPLETIONS Now that the performance regression is fixed, re-enable CONFIG_LOCKDEP_CROSSRELEASE=y and CONFIG_LOCKDEP_COMPLETIONS=y. Signed-off-by: Byungchul Park Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: amir73il@gmail.com Cc: axboe@kernel.dk Cc: darrick.wong@oracle.com Cc: david@fromorbit.com Cc: hch@infradead.org Cc: idryomov@gmail.com Cc: johan@kernel.org Cc: johannes.berg@intel.com Cc: kernel-team@lge.com Cc: linux-block@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-xfs@vger.kernel.org Cc: oleg@redhat.com Cc: tj@kernel.org Link: http://lkml.kernel.org/r/1508921765-15396-6-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar --- lib/Kconfig.debug | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index dfdad67d8f6c..c1e720a22c71 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1092,8 +1092,8 @@ config PROVE_LOCKING select DEBUG_MUTEXES select DEBUG_RT_MUTEXES if RT_MUTEXES select DEBUG_LOCK_ALLOC - select LOCKDEP_CROSSRELEASE if BROKEN - select LOCKDEP_COMPLETIONS if BROKEN + select LOCKDEP_CROSSRELEASE + select LOCKDEP_COMPLETIONS select TRACE_IRQFLAGS default n help From e121d64e16484d4a5eba94cd2fa9eb3848b7c9c2 Mon Sep 17 00:00:00 2001 From: Byungchul Park Date: Wed, 25 Oct 2017 17:56:02 +0900 Subject: [PATCH 49/70] locking/lockdep: Introduce CONFIG_BOOTPARAM_LOCKDEP_CROSSRELEASE_FULLSTACK=y Add a Kconfig knob that enables the lockdep "crossrelease_fullstack" boot parameter. Suggested-by: Ingo Molnar Signed-off-by: Byungchul Park Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: amir73il@gmail.com Cc: axboe@kernel.dk Cc: darrick.wong@oracle.com Cc: david@fromorbit.com Cc: hch@infradead.org Cc: idryomov@gmail.com Cc: johan@kernel.org Cc: johannes.berg@intel.com Cc: kernel-team@lge.com Cc: linux-block@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-xfs@vger.kernel.org Cc: oleg@redhat.com Cc: tj@kernel.org Link: http://lkml.kernel.org/r/1508921765-15396-7-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar --- kernel/locking/lockdep.c | 4 ++++ lib/Kconfig.debug | 15 +++++++++++++++ 2 files changed, 19 insertions(+) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 160b5d6df7cb..db933d063bfc 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -76,7 +76,11 @@ module_param(lock_stat, int, 0644); #define lock_stat 0 #endif +#ifdef CONFIG_BOOTPARAM_LOCKDEP_CROSSRELEASE_FULLSTACK +static int crossrelease_fullstack = 1; +#else static int crossrelease_fullstack; +#endif static int __init allow_crossrelease_fullstack(char *str) { crossrelease_fullstack = 1; diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index c1e720a22c71..2b439a515c30 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1179,6 +1179,21 @@ config LOCKDEP_COMPLETIONS A deadlock caused by wait_for_completion() and complete() can be detected by lockdep using crossrelease feature. +config BOOTPARAM_LOCKDEP_CROSSRELEASE_FULLSTACK + bool "Enable the boot parameter, crossrelease_fullstack" + depends on LOCKDEP_CROSSRELEASE + default n + help + The lockdep "cross-release" feature needs to record stack traces + (of calling functions) for all acquisitions, for eventual later + use during analysis. By default only a single caller is recorded, + because the unwind operation can be very expensive with deeper + stack chains. + + However a boot parameter, crossrelease_fullstack, was + introduced since sometimes deeper traces are required for full + analysis. This option turns on the boot parameter. + config DEBUG_LOCKDEP bool "Lock dependency engine debugging" depends on DEBUG_KERNEL && LOCKDEP From a7967bc31584bd282682981295861e7bcba19e65 Mon Sep 17 00:00:00 2001 From: Byungchul Park Date: Wed, 25 Oct 2017 17:56:03 +0900 Subject: [PATCH 50/70] sched/completions: Add support for initializing completions with lockdep_map Sometimes we want to initialize completions with sparate lockdep maps to assign lock classes as desired. For example, the workqueue code needs to directly manage lockdep maps, since only the code is aware of how to classify lockdep maps properly. Provide additional macros initializing completions in that way. Signed-off-by: Byungchul Park Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: amir73il@gmail.com Cc: axboe@kernel.dk Cc: darrick.wong@oracle.com Cc: david@fromorbit.com Cc: hch@infradead.org Cc: idryomov@gmail.com Cc: johan@kernel.org Cc: johannes.berg@intel.com Cc: kernel-team@lge.com Cc: linux-block@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-xfs@vger.kernel.org Cc: oleg@redhat.com Cc: tj@kernel.org Link: http://lkml.kernel.org/r/1508921765-15396-8-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar --- include/linux/completion.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/include/linux/completion.h b/include/linux/completion.h index 91218036b1c8..4da49916ef3f 100644 --- a/include/linux/completion.h +++ b/include/linux/completion.h @@ -49,6 +49,13 @@ static inline void complete_release_commit(struct completion *x) lock_commit_crosslock((struct lockdep_map *)&x->map); } +#define init_completion_map(x, m) \ +do { \ + lockdep_init_map_crosslock((struct lockdep_map *)&(x)->map, \ + (m)->name, (m)->key, 0); \ + __init_completion(x); \ +} while (0) + #define init_completion(x) \ do { \ static struct lock_class_key __key; \ @@ -58,6 +65,7 @@ do { \ __init_completion(x); \ } while (0) #else +#define init_completion_map(x, m) __init_completion(x) #define init_completion(x) __init_completion(x) static inline void complete_acquire(struct completion *x) {} static inline void complete_release(struct completion *x) {} @@ -73,6 +81,9 @@ static inline void complete_release_commit(struct completion *x) {} { 0, __WAIT_QUEUE_HEAD_INITIALIZER((work).wait) } #endif +#define COMPLETION_INITIALIZER_ONSTACK_MAP(work, map) \ + (*({ init_completion_map(&(work), &(map)); &(work); })) + #define COMPLETION_INITIALIZER_ONSTACK(work) \ (*({ init_completion(&work); &work; })) @@ -102,8 +113,11 @@ static inline void complete_release_commit(struct completion *x) {} #ifdef CONFIG_LOCKDEP # define DECLARE_COMPLETION_ONSTACK(work) \ struct completion work = COMPLETION_INITIALIZER_ONSTACK(work) +# define DECLARE_COMPLETION_ONSTACK_MAP(work, map) \ + struct completion work = COMPLETION_INITIALIZER_ONSTACK_MAP(work, map) #else # define DECLARE_COMPLETION_ONSTACK(work) DECLARE_COMPLETION(work) +# define DECLARE_COMPLETION_ONSTACK_MAP(work, map) DECLARE_COMPLETION(work) #endif /** From fd1a5b04dfb899f84ddeb8acdaea6b98283df1e5 Mon Sep 17 00:00:00 2001 From: Byungchul Park Date: Wed, 25 Oct 2017 17:56:04 +0900 Subject: [PATCH 51/70] workqueue: Remove now redundant lock acquisitions wrt. workqueue flushes The workqueue code added manual lock acquisition annotations to catch deadlocks. After lockdepcrossrelease was introduced, some of those became redundant, since wait_for_completion() already does the acquisition and tracking. Remove the duplicate annotations. Signed-off-by: Byungchul Park Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: amir73il@gmail.com Cc: axboe@kernel.dk Cc: darrick.wong@oracle.com Cc: david@fromorbit.com Cc: hch@infradead.org Cc: idryomov@gmail.com Cc: johan@kernel.org Cc: johannes.berg@intel.com Cc: kernel-team@lge.com Cc: linux-block@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-xfs@vger.kernel.org Cc: oleg@redhat.com Cc: tj@kernel.org Link: http://lkml.kernel.org/r/1508921765-15396-9-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar --- include/linux/workqueue.h | 4 ++-- kernel/workqueue.c | 19 +++---------------- 2 files changed, 5 insertions(+), 18 deletions(-) diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index 1c49431f3121..c8a572cb49be 100644 --- a/include/linux/workqueue.h +++ b/include/linux/workqueue.h @@ -218,7 +218,7 @@ static inline unsigned int work_static(struct work_struct *work) { return 0; } \ __init_work((_work), _onstack); \ (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \ - lockdep_init_map(&(_work)->lockdep_map, #_work, &__key, 0); \ + lockdep_init_map(&(_work)->lockdep_map, "(work_completion)"#_work, &__key, 0); \ INIT_LIST_HEAD(&(_work)->entry); \ (_work)->func = (_func); \ } while (0) @@ -398,7 +398,7 @@ __alloc_workqueue_key(const char *fmt, unsigned int flags, int max_active, static struct lock_class_key __key; \ const char *__lock_name; \ \ - __lock_name = #fmt#args; \ + __lock_name = "(wq_completion)"#fmt#args; \ \ __alloc_workqueue_key((fmt), (flags), (max_active), \ &__key, __lock_name, ##args); \ diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 39831b2f3c5f..160fdc6e839a 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -2497,15 +2497,8 @@ static void insert_wq_barrier(struct pool_workqueue *pwq, INIT_WORK_ONSTACK(&barr->work, wq_barrier_func); __set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(&barr->work)); - /* - * Explicitly init the crosslock for wq_barrier::done, make its lock - * key a subkey of the corresponding work. As a result we won't - * build a dependency between wq_barrier::done and unrelated work. - */ - lockdep_init_map_crosslock((struct lockdep_map *)&barr->done.map, - "(complete)wq_barr::done", - target->lockdep_map.key, 1); - __init_completion(&barr->done); + init_completion_map(&barr->done, &target->lockdep_map); + barr->task = current; /* @@ -2611,16 +2604,13 @@ void flush_workqueue(struct workqueue_struct *wq) struct wq_flusher this_flusher = { .list = LIST_HEAD_INIT(this_flusher.list), .flush_color = -1, - .done = COMPLETION_INITIALIZER_ONSTACK(this_flusher.done), + .done = COMPLETION_INITIALIZER_ONSTACK_MAP(this_flusher.done, wq->lockdep_map), }; int next_color; if (WARN_ON(!wq_online)) return; - lock_map_acquire(&wq->lockdep_map); - lock_map_release(&wq->lockdep_map); - mutex_lock(&wq->mutex); /* @@ -2883,9 +2873,6 @@ bool flush_work(struct work_struct *work) if (WARN_ON(!wq_online)) return false; - lock_map_acquire(&work->lockdep_map); - lock_map_release(&work->lockdep_map); - if (start_flush_work(work, &barr)) { wait_for_completion(&barr.done); destroy_work_on_stack(&barr.work); From e319e1fbd9d42420ab6eec0bfd75eb9ad7ca63b1 Mon Sep 17 00:00:00 2001 From: Byungchul Park Date: Wed, 25 Oct 2017 17:56:05 +0900 Subject: [PATCH 52/70] block, locking/lockdep: Assign a lock_class per gendisk used for wait_for_completion() Darrick posted the following warning and Dave Chinner analyzed it: > ====================================================== > WARNING: possible circular locking dependency detected > 4.14.0-rc1-fixes #1 Tainted: G W > ------------------------------------------------------ > loop0/31693 is trying to acquire lock: > (&(&ip->i_mmaplock)->mr_lock){++++}, at: [] xfs_ilock+0x23c/0x330 [xfs] > > but now in release context of a crosslock acquired at the following: > ((complete)&ret.event){+.+.}, at: [] submit_bio_wait+0x7f/0xb0 > > which lock already depends on the new lock. > > the existing dependency chain (in reverse order) is: > > -> #2 ((complete)&ret.event){+.+.}: > lock_acquire+0xab/0x200 > wait_for_completion_io+0x4e/0x1a0 > submit_bio_wait+0x7f/0xb0 > blkdev_issue_zeroout+0x71/0xa0 > xfs_bmapi_convert_unwritten+0x11f/0x1d0 [xfs] > xfs_bmapi_write+0x374/0x11f0 [xfs] > xfs_iomap_write_direct+0x2ac/0x430 [xfs] > xfs_file_iomap_begin+0x20d/0xd50 [xfs] > iomap_apply+0x43/0xe0 > dax_iomap_rw+0x89/0xf0 > xfs_file_dax_write+0xcc/0x220 [xfs] > xfs_file_write_iter+0xf0/0x130 [xfs] > __vfs_write+0xd9/0x150 > vfs_write+0xc8/0x1c0 > SyS_write+0x45/0xa0 > entry_SYSCALL_64_fastpath+0x1f/0xbe > > -> #1 (&xfs_nondir_ilock_class){++++}: > lock_acquire+0xab/0x200 > down_write_nested+0x4a/0xb0 > xfs_ilock+0x263/0x330 [xfs] > xfs_setattr_size+0x152/0x370 [xfs] > xfs_vn_setattr+0x6b/0x90 [xfs] > notify_change+0x27d/0x3f0 > do_truncate+0x5b/0x90 > path_openat+0x237/0xa90 > do_filp_open+0x8a/0xf0 > do_sys_open+0x11c/0x1f0 > entry_SYSCALL_64_fastpath+0x1f/0xbe > > -> #0 (&(&ip->i_mmaplock)->mr_lock){++++}: > up_write+0x1c/0x40 > xfs_iunlock+0x1d0/0x310 [xfs] > xfs_file_fallocate+0x8a/0x310 [xfs] > loop_queue_work+0xb7/0x8d0 > kthread_worker_fn+0xb9/0x1f0 > > Chain exists of: > &(&ip->i_mmaplock)->mr_lock --> &xfs_nondir_ilock_class --> (complete)&ret.event > > Possible unsafe locking scenario by crosslock: > > CPU0 CPU1 > ---- ---- > lock(&xfs_nondir_ilock_class); > lock((complete)&ret.event); > lock(&(&ip->i_mmaplock)->mr_lock); > unlock((complete)&ret.event); > > *** DEADLOCK *** The warning is a false positive, caused by the fact that all wait_for_completion()s in submit_bio_wait() are waiting with the same lock class. However, some bios have nothing to do with others, for example in the case of loop devices, there's no direct connection between the bios of an upper device and the bios of a lower device(=loop device). The safest way to assign different lock classes to different devices is to do it for each gendisk. In other words, this patch assigns a lockdep_map per gendisk and uses it when initializing completion in submit_bio_wait(). Analyzed-by: Dave Chinner Reported-by: Darrick J. Wong Signed-off-by: Byungchul Park Reviewed-by: Jens Axboe Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: amir73il@gmail.com Cc: axboe@kernel.dk Cc: david@fromorbit.com Cc: hch@infradead.org Cc: idryomov@gmail.com Cc: johan@kernel.org Cc: johannes.berg@intel.com Cc: kernel-team@lge.com Cc: linux-block@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-xfs@vger.kernel.org Cc: oleg@redhat.com Cc: tj@kernel.org Link: http://lkml.kernel.org/r/1508921765-15396-10-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar --- block/bio.c | 2 +- block/genhd.c | 10 ++-------- include/linux/genhd.h | 22 ++++++++++++++++++++-- 3 files changed, 23 insertions(+), 11 deletions(-) diff --git a/block/bio.c b/block/bio.c index 5e901bfc0576..cc60213e56d8 100644 --- a/block/bio.c +++ b/block/bio.c @@ -935,7 +935,7 @@ static void submit_bio_wait_endio(struct bio *bio) */ int submit_bio_wait(struct bio *bio) { - DECLARE_COMPLETION_ONSTACK(done); + DECLARE_COMPLETION_ONSTACK_MAP(done, bio->bi_disk->lockdep_map); bio->bi_private = &done; bio->bi_end_io = submit_bio_wait_endio; diff --git a/block/genhd.c b/block/genhd.c index dd305c65ffb0..630c0da6cfcf 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -1354,13 +1354,7 @@ dev_t blk_lookup_devt(const char *name, int partno) } EXPORT_SYMBOL(blk_lookup_devt); -struct gendisk *alloc_disk(int minors) -{ - return alloc_disk_node(minors, NUMA_NO_NODE); -} -EXPORT_SYMBOL(alloc_disk); - -struct gendisk *alloc_disk_node(int minors, int node_id) +struct gendisk *__alloc_disk_node(int minors, int node_id) { struct gendisk *disk; struct disk_part_tbl *ptbl; @@ -1411,7 +1405,7 @@ struct gendisk *alloc_disk_node(int minors, int node_id) } return disk; } -EXPORT_SYMBOL(alloc_disk_node); +EXPORT_SYMBOL(__alloc_disk_node); struct kobject *get_disk(struct gendisk *disk) { diff --git a/include/linux/genhd.h b/include/linux/genhd.h index ea652bfcd675..19d18710546a 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -206,6 +206,7 @@ struct gendisk { #endif /* CONFIG_BLK_DEV_INTEGRITY */ int node_id; struct badblocks *bb; + struct lockdep_map lockdep_map; }; static inline struct gendisk *part_to_disk(struct hd_struct *part) @@ -590,8 +591,7 @@ extern void __delete_partition(struct percpu_ref *); extern void delete_partition(struct gendisk *, int); extern void printk_all_partitions(void); -extern struct gendisk *alloc_disk_node(int minors, int node_id); -extern struct gendisk *alloc_disk(int minors); +extern struct gendisk *__alloc_disk_node(int minors, int node_id); extern struct kobject *get_disk(struct gendisk *disk); extern void put_disk(struct gendisk *disk); extern void blk_register_region(dev_t devt, unsigned long range, @@ -615,6 +615,24 @@ extern ssize_t part_fail_store(struct device *dev, const char *buf, size_t count); #endif /* CONFIG_FAIL_MAKE_REQUEST */ +#define alloc_disk_node(minors, node_id) \ +({ \ + static struct lock_class_key __key; \ + const char *__name; \ + struct gendisk *__disk; \ + \ + __name = "(gendisk_completion)"#minors"("#node_id")"; \ + \ + __disk = __alloc_disk_node(minors, node_id); \ + \ + if (__disk) \ + lockdep_init_map(&__disk->lockdep_map, __name, &__key, 0); \ + \ + __disk; \ +}) + +#define alloc_disk(minors) alloc_disk_node(minors, NUMA_NO_NODE) + static inline int hd_ref_init(struct hd_struct *part) { if (percpu_ref_init(&part->ref, __delete_partition, 0, From ca5d376e17072c1b60c3fee66f3be58ef018952d Mon Sep 17 00:00:00 2001 From: Dou Liyang Date: Sat, 28 Oct 2017 14:06:44 +0800 Subject: [PATCH 53/70] x86/paravirt: Set up the virt_spin_lock_key after static keys get initialized Commit: 9043442b43b1 ("locking/paravirt: Use new static key for controlling call of virt_spin_lock()") sets the static virt_spin_lock_key to a value before jump_label_init() has been called, which will result in a WARN(). Reorder the initialization sequence: - Move the native_pv_lock_init() into native_smp_prepare_cpus() - set the value in xen_init_lock_cpu() to avoid calling into the not yet initialized static keys subsystem. Suggested-by: Juergen Gross Reported-by: Juergen Gross Signed-off-by: Dou Liyang Reviewed-by: Juergen Gross Acked-by: Thomas Gleixner Cc: Linus Torvalds Cc: Peter Zijlstra Cc: boris.ostrovsky@oracle.com Cc: bp@suse.de Cc: luto@kernel.org Cc: vkuznets@redhat.com Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1509170804-3813-1-git-send-email-douly.fnst@cn.fujitsu.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/smpboot.c | 3 ++- arch/x86/xen/spinlock.c | 6 ++++-- 2 files changed, 6 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 361f91674ce5..198416ddff01 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1358,6 +1358,8 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus) pr_info("CPU0: "); print_cpu_info(&cpu_data(0)); + native_pv_lock_init(); + uv_system_init(); set_mtrr_aps_delayed_init(); @@ -1385,7 +1387,6 @@ void __init native_smp_prepare_boot_cpu(void) /* already set me in cpu_online_mask in boot_cpu_init() */ cpumask_set_cpu(me, cpu_callout_mask); cpu_set_state_online(me); - native_pv_lock_init(); } void __init native_smp_cpus_done(unsigned int max_cpus) diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c index e8ab80ad7a6f..1e1462d3d43e 100644 --- a/arch/x86/xen/spinlock.c +++ b/arch/x86/xen/spinlock.c @@ -81,8 +81,11 @@ void xen_init_lock_cpu(int cpu) int irq; char *name; - if (!xen_pvspin) + if (!xen_pvspin) { + if (cpu == 0) + static_branch_disable(&virt_spin_lock_key); return; + } WARN(per_cpu(lock_kicker_irq, cpu) >= 0, "spinlock on CPU%d exists on IRQ%d!\n", cpu, per_cpu(lock_kicker_irq, cpu)); @@ -130,7 +133,6 @@ void __init xen_init_spinlocks(void) if (!xen_pvspin) { printk(KERN_DEBUG "xen: PV spinlocks disabled\n"); - static_branch_disable(&virt_spin_lock_key); return; } printk(KERN_DEBUG "xen: PV spinlocks enabled\n"); From f791dd2589d7e217625d7e411621a5bac71cbf69 Mon Sep 17 00:00:00 2001 From: Cheng Jian Date: Fri, 3 Nov 2017 18:59:48 +0800 Subject: [PATCH 54/70] locking/rwlocks: Fix comments - fix the list of locking API headers in kernel/locking/spinlock.c - fix an #endif comment Signed-off-by: Cheng Jian Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: huawei.libin@huawei.com Cc: xiexiuqi@huawei.com Link: http://lkml.kernel.org/r/1509706788-152547-1-git-send-email-cj.chengjian@huawei.com Signed-off-by: Ingo Molnar --- include/linux/rwlock_api_smp.h | 2 +- kernel/locking/spinlock.c | 3 ++- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/include/linux/rwlock_api_smp.h b/include/linux/rwlock_api_smp.h index 5b9b84b20407..86ebb4bf9c6e 100644 --- a/include/linux/rwlock_api_smp.h +++ b/include/linux/rwlock_api_smp.h @@ -211,7 +211,7 @@ static inline void __raw_write_lock(rwlock_t *lock) LOCK_CONTENDED(lock, do_raw_write_trylock, do_raw_write_lock); } -#endif /* CONFIG_PREEMPT */ +#endif /* !CONFIG_GENERIC_LOCKBREAK || CONFIG_DEBUG_LOCK_ALLOC */ static inline void __raw_write_unlock(rwlock_t *lock) { diff --git a/kernel/locking/spinlock.c b/kernel/locking/spinlock.c index b96343374a87..1fd1a7543cdd 100644 --- a/kernel/locking/spinlock.c +++ b/kernel/locking/spinlock.c @@ -30,7 +30,8 @@ #if !defined(CONFIG_GENERIC_LOCKBREAK) || defined(CONFIG_DEBUG_LOCK_ALLOC) /* * The __lock_function inlines are taken from - * include/linux/spinlock_api_smp.h + * spinlock : include/linux/spinlock_api_smp.h + * rwlock : include/linux/rwlock_api_smp.h */ #else From 11752adb68a388724b1935d57bf543897c34d80b Mon Sep 17 00:00:00 2001 From: Waiman Long Date: Tue, 7 Nov 2017 16:18:06 -0500 Subject: [PATCH 55/70] locking/pvqspinlock: Implement hybrid PV queued/unfair locks MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently, all the lock waiters entering the slowpath will do one lock stealing attempt to acquire the lock. That helps performance, especially in VMs with over-committed vCPUs. However, the current pvqspinlocks still don't perform as good as unfair locks in many cases. On the other hands, unfair locks do have the problem of lock starvation that pvqspinlocks don't have. This patch combines the best attributes of an unfair lock and a pvqspinlock into a hybrid lock with 2 modes - queued mode & unfair mode. A lock waiter goes into the unfair mode when there are waiters in the wait queue but the pending bit isn't set. Otherwise, it will go into the queued mode waiting in the queue for its turn. On a 2-socket 36-core E5-2699 v3 system (HT off), a kernel build (make -j) was done in a VM with unpinned vCPUs 3 times with the best time selected and is the number of vCPUs available. The build times of the original pvqspinlock, hybrid pvqspinlock and unfair lock with various number of vCPUs are as follows: vCPUs pvqlock hybrid pvqlock unfair lock ----- ------- -------------- ----------- 30 342.1s 329.1s 329.1s 36 314.1s 305.3s 307.3s 45 345.0s 302.1s 306.6s 54 365.4s 308.6s 307.8s 72 358.9s 293.6s 303.9s 108 343.0s 285.9s 304.2s The hybrid pvqspinlock performs better or comparable to the unfair lock. By turning on QUEUED_LOCK_STAT, the table below showed the number of lock acquisitions in unfair mode and queue mode after a kernel build with various number of vCPUs. vCPUs queued mode unfair mode ----- ----------- ----------- 30 9,130,518 294,954 36 10,856,614 386,809 45 8,467,264 11,475,373 54 6,409,987 19,670,855 72 4,782,063 25,712,180 It can be seen that as the VM became more and more over-committed, the ratio of locks acquired in unfair mode increases. This is all done automatically to get the best overall performance as possible. Using a kernel locking microbenchmark with number of locking threads equals to the number of vCPUs available on the same machine, the minimum, average and maximum (min/avg/max) numbers of locking operations done per thread in a 5-second testing interval are shown below: vCPUs hybrid pvqlock unfair lock ----- -------------- ----------- 36 822,135/881,063/950,363 75,570/313,496/ 690,465 54 542,435/581,664/625,937 35,460/204,280/ 457,172 72 397,500/428,177/499,299 17,933/150,679/ 708,001 108 257,898/288,150/340,871 3,085/181,176/1,257,109 It can be seen that the hybrid pvqspinlocks are more fair and performant than the unfair locks in this test. The table below shows the kernel build times on a smaller 2-socket 16-core 32-thread E5-2620 v4 system. vCPUs pvqlock hybrid pvqlock unfair lock ----- ------- -------------- ----------- 16 436.8s 433.4s 435.6s 36 366.2s 364.8s 364.5s 48 423.6s 376.3s 370.2s 64 433.1s 376.6s 376.8s Again, the performance of the hybrid pvqspinlock was comparable to that of the unfair lock. Signed-off-by: Waiman Long Reviewed-by: Juergen Gross Reviewed-by: Eduardo Valentin Acked-by: Peter Zijlstra Cc: Boris Ostrovsky Cc: Linus Torvalds Cc: Paolo Bonzini Cc: Radim Krčmář Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1510089486-3466-1-git-send-email-longman@redhat.com Signed-off-by: Ingo Molnar --- kernel/locking/qspinlock_paravirt.h | 47 +++++++++++++++++++++++------ 1 file changed, 38 insertions(+), 9 deletions(-) diff --git a/kernel/locking/qspinlock_paravirt.h b/kernel/locking/qspinlock_paravirt.h index 15b6a39366c6..6ee477765e6c 100644 --- a/kernel/locking/qspinlock_paravirt.h +++ b/kernel/locking/qspinlock_paravirt.h @@ -61,21 +61,50 @@ struct pv_node { #include "qspinlock_stat.h" /* + * Hybrid PV queued/unfair lock + * * By replacing the regular queued_spin_trylock() with the function below, * it will be called once when a lock waiter enter the PV slowpath before - * being queued. By allowing one lock stealing attempt here when the pending - * bit is off, it helps to reduce the performance impact of lock waiter - * preemption without the drawback of lock starvation. + * being queued. + * + * The pending bit is set by the queue head vCPU of the MCS wait queue in + * pv_wait_head_or_lock() to signal that it is ready to spin on the lock. + * When that bit becomes visible to the incoming waiters, no lock stealing + * is allowed. The function will return immediately to make the waiters + * enter the MCS wait queue. So lock starvation shouldn't happen as long + * as the queued mode vCPUs are actively running to set the pending bit + * and hence disabling lock stealing. + * + * When the pending bit isn't set, the lock waiters will stay in the unfair + * mode spinning on the lock unless the MCS wait queue is empty. In this + * case, the lock waiters will enter the queued mode slowpath trying to + * become the queue head and set the pending bit. + * + * This hybrid PV queued/unfair lock combines the best attributes of a + * queued lock (no lock starvation) and an unfair lock (good performance + * on not heavily contended locks). */ -#define queued_spin_trylock(l) pv_queued_spin_steal_lock(l) -static inline bool pv_queued_spin_steal_lock(struct qspinlock *lock) +#define queued_spin_trylock(l) pv_hybrid_queued_unfair_trylock(l) +static inline bool pv_hybrid_queued_unfair_trylock(struct qspinlock *lock) { struct __qspinlock *l = (void *)lock; - if (!(atomic_read(&lock->val) & _Q_LOCKED_PENDING_MASK) && - (cmpxchg_acquire(&l->locked, 0, _Q_LOCKED_VAL) == 0)) { - qstat_inc(qstat_pv_lock_stealing, true); - return true; + /* + * Stay in unfair lock mode as long as queued mode waiters are + * present in the MCS wait queue but the pending bit isn't set. + */ + for (;;) { + int val = atomic_read(&lock->val); + + if (!(val & _Q_LOCKED_PENDING_MASK) && + (cmpxchg_acquire(&l->locked, 0, _Q_LOCKED_VAL) == 0)) { + qstat_inc(qstat_pv_lock_stealing, true); + return true; + } + if (!(val & _Q_TAIL_MASK) || (val & _Q_PENDING_MASK)) + break; + + cpu_relax(); } return false; From f54bb2ec02c839f6bfe3e8d438cd93d30b4809dd Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 6 Nov 2017 16:01:17 +0100 Subject: [PATCH 56/70] locking/lockdep: Add IRQs disabled/enabled assertion APIs: lockdep_assert_irqs_enabled()/disabled() Checking whether IRQs are enabled or disabled is a very common sanity check, however not free of overhead especially on fastpath where such assertion is very common. Lockdep is a good host for such concurrency correctness check and it even already tracks down IRQs disablement state. Just reuse its machinery. This will allow us to get rid of the flags pop and check overhead from fast path when kernel is built for production. Suggested-by: Peter Zijlstra Signed-off-by: Frederic Weisbecker Acked-by: Thomas Gleixner Cc: David S . Miller Cc: Lai Jiangshan Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Tejun Heo Link: http://lkml.kernel.org/r/1509980490-4285-2-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar --- include/linux/lockdep.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 02720769c159..a842551fe044 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -725,9 +725,24 @@ do { \ lock_acquire(&(lock)->dep_map, 0, 0, 1, 1, NULL, _THIS_IP_); \ lock_release(&(lock)->dep_map, 0, _THIS_IP_); \ } while (0) + +#define lockdep_assert_irqs_enabled() do { \ + WARN_ONCE(debug_locks && !current->lockdep_recursion && \ + !current->hardirqs_enabled, \ + "IRQs not enabled as expected\n"); \ + } while (0) + +#define lockdep_assert_irqs_disabled() do { \ + WARN_ONCE(debug_locks && !current->lockdep_recursion && \ + current->hardirqs_enabled, \ + "IRQs not disabled as expected\n"); \ + } while (0) + #else # define might_lock(lock) do { } while (0) # define might_lock_read(lock) do { } while (0) +# define lockdep_assert_irqs_enabled() do { } while (0) +# define lockdep_assert_irqs_disabled() do { } while (0) #endif #ifdef CONFIG_LOCKDEP From f71b74bca637fca7de78f1d44eaefde5bc900f9f Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 6 Nov 2017 16:01:18 +0100 Subject: [PATCH 57/70] irq/softirqs: Use lockdep to assert IRQs are disabled/enabled Use lockdep to check that IRQs are enabled or disabled as expected. This way the sanity check only shows overhead when concurrency correctness debug code is enabled. Signed-off-by: Frederic Weisbecker Acked-by: Thomas Gleixner Cc: David S . Miller Cc: Lai Jiangshan Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Tejun Heo Link: http://lkml.kernel.org/r/1509980490-4285-3-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar --- kernel/softirq.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/kernel/softirq.c b/kernel/softirq.c index 4e09821f9d9e..662f7b1b7a78 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -137,7 +137,7 @@ EXPORT_SYMBOL(__local_bh_disable_ip); static void __local_bh_enable(unsigned int cnt) { - WARN_ON_ONCE(!irqs_disabled()); + lockdep_assert_irqs_disabled(); if (softirq_count() == (cnt & SOFTIRQ_MASK)) trace_softirqs_on(_RET_IP_); @@ -158,7 +158,8 @@ EXPORT_SYMBOL(_local_bh_enable); void __local_bh_enable_ip(unsigned long ip, unsigned int cnt) { - WARN_ON_ONCE(in_irq() || irqs_disabled()); + WARN_ON_ONCE(in_irq()); + lockdep_assert_irqs_enabled(); #ifdef CONFIG_TRACE_IRQFLAGS local_irq_disable(); #endif @@ -396,9 +397,8 @@ void irq_exit(void) #ifndef __ARCH_IRQ_EXIT_IRQS_DISABLED local_irq_disable(); #else - WARN_ON_ONCE(!irqs_disabled()); + lockdep_assert_irqs_disabled(); #endif - account_irq_exit_time(current); preempt_count_sub(HARDIRQ_OFFSET); if (!in_interrupt() && local_softirq_pending()) @@ -488,7 +488,7 @@ EXPORT_SYMBOL(__tasklet_hi_schedule); void __tasklet_hi_schedule_first(struct tasklet_struct *t) { - BUG_ON(!irqs_disabled()); + lockdep_assert_irqs_disabled(); t->next = __this_cpu_read(tasklet_hi_vec.head); __this_cpu_write(tasklet_hi_vec.head, t); From 8e8eb730759f9cfd7a761b0b4ee41d714e720993 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 6 Nov 2017 16:01:19 +0100 Subject: [PATCH 58/70] workqueue: Use lockdep to assert IRQs are disabled/enabled Use lockdep to check that IRQs are enabled or disabled as expected. This way the sanity check only shows overhead when concurrency correctness debug code is enabled. Signed-off-by: Frederic Weisbecker Acked-by: Thomas Gleixner Acked-by: Tejun Heo Cc: David S . Miller Cc: Lai Jiangshan Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1509980490-4285-4-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar --- kernel/workqueue.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 1070b21ba4aa..13f67b5a0a0c 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1376,7 +1376,7 @@ static void __queue_work(int cpu, struct workqueue_struct *wq, * queued or lose PENDING. Grabbing PENDING and queueing should * happen with IRQ disabled. */ - WARN_ON_ONCE(!irqs_disabled()); + lockdep_assert_irqs_disabled(); debug_work_activate(work); From ebf3adbad012b89c4a51a3beae718a587d988a3a Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 6 Nov 2017 16:01:20 +0100 Subject: [PATCH 59/70] timers/nohz: Use lockdep to assert IRQs are disabled/enabled Use lockdep to check that IRQs are enabled or disabled as expected. This way the sanity check only shows overhead when concurrency correctness debug code is enabled. Signed-off-by: Frederic Weisbecker Acked-by: Thomas Gleixner Cc: David S . Miller Cc: Lai Jiangshan Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Tejun Heo Link: http://lkml.kernel.org/r/1509980490-4285-5-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar --- kernel/time/tick-sched.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index c7a899c5ce64..dd4b7b492c9b 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -198,7 +198,7 @@ static bool check_tick_dependency(atomic_t *dep) static bool can_stop_full_tick(int cpu, struct tick_sched *ts) { - WARN_ON_ONCE(!irqs_disabled()); + lockdep_assert_irqs_disabled(); if (unlikely(!cpu_online(cpu))) return false; @@ -960,8 +960,7 @@ void tick_nohz_idle_enter(void) { struct tick_sched *ts; - WARN_ON_ONCE(irqs_disabled()); - + lockdep_assert_irqs_enabled(); /* * Update the idle state in the scheduler domain hierarchy * when tick_nohz_stop_sched_tick() is called from the idle loop. From 53bef3fd47f69e40b52c9f9acd3551dfff9f8702 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 6 Nov 2017 16:01:21 +0100 Subject: [PATCH 60/70] timers/hrtimer: Use lockdep to assert IRQs are disabled/enabled Use lockdep to check that IRQs are enabled or disabled as expected. This way the sanity check only shows overhead when concurrency correctness debug code is enabled. Signed-off-by: Frederic Weisbecker Acked-by: Thomas Gleixner Cc: David S . Miller Cc: Lai Jiangshan Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Tejun Heo Link: http://lkml.kernel.org/r/1509980490-4285-6-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar --- kernel/time/hrtimer.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 88f75f92ef36..d32520840fde 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -758,9 +758,7 @@ void clock_was_set(void) */ void hrtimers_resume(void) { - WARN_ONCE(!irqs_disabled(), - KERN_INFO "hrtimers_resume() called with IRQs enabled!"); - + lockdep_assert_irqs_disabled(); /* Retrigger on the local CPU */ retrigger_next_event(NULL); /* And schedule a retrigger for all others */ From 83efcbd028ad3aec36b5a3882cfa32490c135df7 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 6 Nov 2017 16:01:22 +0100 Subject: [PATCH 61/70] smp/core: Use lockdep to assert IRQs are disabled/enabled Use lockdep to check that IRQs are enabled or disabled as expected. This way the sanity check only shows overhead when concurrency correctness debug code is enabled. Signed-off-by: Frederic Weisbecker Acked-by: Thomas Gleixner Cc: David S . Miller Cc: Lai Jiangshan Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Tejun Heo Link: http://lkml.kernel.org/r/1509980490-4285-7-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar --- kernel/smp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/smp.c b/kernel/smp.c index c94dd85c8d41..084c8b3a2681 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -213,7 +213,7 @@ static void flush_smp_call_function_queue(bool warn_cpu_offline) call_single_data_t *csd, *csd_next; static bool warned; - WARN_ON(!irqs_disabled()); + lockdep_assert_irqs_disabled(); head = this_cpu_ptr(&call_single_queue); entry = llist_del_all(head); From 7a10e2a9190628a4024ea394ce7bd641ae40ffd1 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 6 Nov 2017 16:01:23 +0100 Subject: [PATCH 62/70] x86: Use lockdep to assert IRQs are disabled/enabled Use lockdep to check that IRQs are enabled or disabled as expected. This way the sanity check only shows overhead when concurrency correctness debug code is enabled. It also makes no more sense to fix the IRQ flags when a bug is detected as the assertion is now pure config-dependent debugging. And to quote Peter Zijlstra: The whole if !disabled, disable logic is uber paranoid programming, but I don't think we've ever seen that WARN trigger, and if it does (and then burns the kernel) we at least know what happend. Signed-off-by: Frederic Weisbecker Acked-by: Thomas Gleixner Cc: David S . Miller Cc: Lai Jiangshan Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Tejun Heo Link: http://lkml.kernel.org/r/1509980490-4285-8-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar --- arch/x86/entry/common.c | 4 +--- arch/x86/kernel/smpboot.c | 2 +- 2 files changed, 2 insertions(+), 4 deletions(-) diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index eaa0ba66cf96..d7d3cc24baf4 100644 --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -186,9 +186,7 @@ __visible inline void prepare_exit_to_usermode(struct pt_regs *regs) addr_limit_user_check(); - if (IS_ENABLED(CONFIG_PROVE_LOCKING) && WARN_ON(!irqs_disabled())) - local_irq_disable(); - + lockdep_assert_irqs_disabled(); lockdep_sys_exit(); cached_flags = READ_ONCE(ti->flags); diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 198416ddff01..4008b6b9ad72 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1095,7 +1095,7 @@ int native_cpu_up(unsigned int cpu, struct task_struct *tidle) unsigned long flags; int err, ret = 0; - WARN_ON(irqs_disabled()); + lockdep_assert_irqs_enabled(); pr_debug("++++++++++++++++++++=_---CPU UP %u\n", cpu); From 164446455a5d3f1402b5a0ea42acce33fd576ed7 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 6 Nov 2017 16:01:24 +0100 Subject: [PATCH 63/70] perf/core: Use lockdep to assert IRQs are disabled/enabled Use lockdep to check that IRQs are enabled or disabled as expected. This way the sanity check only shows overhead when concurrency correctness debug code is enabled. Signed-off-by: Frederic Weisbecker Acked-by: Thomas Gleixner Cc: David S . Miller Cc: Lai Jiangshan Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Tejun Heo Link: http://lkml.kernel.org/r/1509980490-4285-9-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar --- kernel/events/core.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index b315aebbcc3f..c298847d4b85 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -209,7 +209,7 @@ static int event_function(void *info) struct perf_event_context *task_ctx = cpuctx->task_ctx; int ret = 0; - WARN_ON_ONCE(!irqs_disabled()); + lockdep_assert_irqs_disabled(); perf_ctx_lock(cpuctx, task_ctx); /* @@ -306,7 +306,7 @@ static void event_function_local(struct perf_event *event, event_f func, void *d struct task_struct *task = READ_ONCE(ctx->task); struct perf_event_context *task_ctx = NULL; - WARN_ON_ONCE(!irqs_disabled()); + lockdep_assert_irqs_disabled(); if (task) { if (task == TASK_TOMBSTONE) @@ -1006,7 +1006,7 @@ static enum hrtimer_restart perf_mux_hrtimer_handler(struct hrtimer *hr) struct perf_cpu_context *cpuctx; int rotations = 0; - WARN_ON(!irqs_disabled()); + lockdep_assert_irqs_disabled(); cpuctx = container_of(hr, struct perf_cpu_context, hrtimer); rotations = perf_rotate_context(cpuctx); @@ -1093,7 +1093,7 @@ static void perf_event_ctx_activate(struct perf_event_context *ctx) { struct list_head *head = this_cpu_ptr(&active_ctx_list); - WARN_ON(!irqs_disabled()); + lockdep_assert_irqs_disabled(); WARN_ON(!list_empty(&ctx->active_ctx_list)); @@ -1102,7 +1102,7 @@ static void perf_event_ctx_activate(struct perf_event_context *ctx) static void perf_event_ctx_deactivate(struct perf_event_context *ctx) { - WARN_ON(!irqs_disabled()); + lockdep_assert_irqs_disabled(); WARN_ON(list_empty(&ctx->active_ctx_list)); @@ -3523,7 +3523,7 @@ void perf_event_task_tick(void) struct perf_event_context *ctx, *tmp; int throttled; - WARN_ON(!irqs_disabled()); + lockdep_assert_irqs_disabled(); __this_cpu_inc(perf_throttled_seq); throttled = __this_cpu_xchg(perf_throttled_count, 0); From a934d4d15f040cdd254350e7270b35cc7521e12e Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 6 Nov 2017 16:01:25 +0100 Subject: [PATCH 64/70] irq/timings: Use lockdep to assert IRQs are disabled/enabled Use lockdep to check that IRQs are enabled or disabled as expected. This way the sanity check only shows overhead when concurrency correctness debug code is enabled. Signed-off-by: Frederic Weisbecker Acked-by: Thomas Gleixner Cc: David S . Miller Cc: Lai Jiangshan Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Tejun Heo Link: http://lkml.kernel.org/r/1509980490-4285-10-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar --- kernel/irq/timings.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/irq/timings.c b/kernel/irq/timings.c index c8c1d073fbf1..e0923fa4927a 100644 --- a/kernel/irq/timings.c +++ b/kernel/irq/timings.c @@ -264,7 +264,7 @@ u64 irq_timings_next_event(u64 now) * order to prevent the timings circular buffer to be updated * while we are reading it. */ - WARN_ON_ONCE(!irqs_disabled()); + lockdep_assert_irqs_disabled(); /* * Number of elements in the circular buffer: If it happens it From 3c7169a3bf8216a56761a8edf775072dd36a00a0 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 6 Nov 2017 16:01:26 +0100 Subject: [PATCH 65/70] irq_work: Use lockdep to assert IRQs are disabled/enabled Use lockdep to check that IRQs are enabled or disabled as expected. This way the sanity check only shows overhead when concurrency correctness debug code is enabled. Signed-off-by: Frederic Weisbecker Acked-by: Thomas Gleixner Cc: David S . Miller Cc: Lai Jiangshan Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Tejun Heo Link: http://lkml.kernel.org/r/1509980490-4285-11-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar --- kernel/irq_work.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/irq_work.c b/kernel/irq_work.c index bcf107ce0854..899579657a0a 100644 --- a/kernel/irq_work.c +++ b/kernel/irq_work.c @@ -188,7 +188,7 @@ void irq_work_tick(void) */ void irq_work_sync(struct irq_work *work) { - WARN_ON_ONCE(irqs_disabled()); + lockdep_assert_irqs_enabled(); while (work->flags & IRQ_WORK_BUSY) cpu_relax(); From 2c11dba00a39007b457c7607c1b1a4db95ca04bc Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 6 Nov 2017 16:01:27 +0100 Subject: [PATCH 66/70] sched/clock, sched/cputime: Use lockdep to assert IRQs are disabled/enabled Use lockdep to check that IRQs are enabled or disabled as expected. This way the sanity check only shows overhead when concurrency correctness debug code is enabled. Signed-off-by: Frederic Weisbecker Acked-by: Thomas Gleixner Cc: David S . Miller Cc: Lai Jiangshan Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Tejun Heo Link: http://lkml.kernel.org/r/1509980490-4285-12-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar --- kernel/sched/clock.c | 2 +- kernel/sched/cputime.c | 3 +-- 2 files changed, 2 insertions(+), 3 deletions(-) diff --git a/kernel/sched/clock.c b/kernel/sched/clock.c index ca0f8fc945c6..e086babe6c61 100644 --- a/kernel/sched/clock.c +++ b/kernel/sched/clock.c @@ -388,7 +388,7 @@ void sched_clock_tick(void) if (unlikely(!sched_clock_running)) return; - WARN_ON_ONCE(!irqs_disabled()); + lockdep_assert_irqs_disabled(); scd = this_scd(); __scd_stamp(scd); diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c index 14d2dbf97c53..9be8b68a66da 100644 --- a/kernel/sched/cputime.c +++ b/kernel/sched/cputime.c @@ -259,8 +259,7 @@ static inline u64 account_other_time(u64 max) { u64 accounted; - /* Shall be converted to a lockdep-enabled lightweight check */ - WARN_ON_ONCE(!irqs_disabled()); + lockdep_assert_irqs_disabled(); accounted = steal_account_process_time(max); From a69682200db9c2c26594188f81dd2df560af4683 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 6 Nov 2017 16:01:28 +0100 Subject: [PATCH 67/70] timers/posix-cpu-timers: Use lockdep to assert IRQs are disabled/enabled Use lockdep to check that IRQs are enabled or disabled as expected. This way the sanity check only shows overhead when concurrency correctness debug code is enabled. Signed-off-by: Frederic Weisbecker Acked-by: Thomas Gleixner Cc: David S . Miller Cc: Lai Jiangshan Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Tejun Heo Link: http://lkml.kernel.org/r/1509980490-4285-13-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar --- kernel/time/posix-cpu-timers.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c index 5b117110b55b..1f27887aa194 100644 --- a/kernel/time/posix-cpu-timers.c +++ b/kernel/time/posix-cpu-timers.c @@ -603,7 +603,7 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags, /* * Disarm any old timer after extracting its expiry time. */ - WARN_ON_ONCE(!irqs_disabled()); + lockdep_assert_irqs_disabled(); ret = 0; old_incr = timer->it.cpu.incr; @@ -1034,7 +1034,7 @@ static void posix_cpu_timer_rearm(struct k_itimer *timer) /* * Now re-arm for the new expiry time. */ - WARN_ON_ONCE(!irqs_disabled()); + lockdep_assert_irqs_disabled(); arm_timer(timer); unlock: unlock_task_sighand(p, &flags); @@ -1125,7 +1125,7 @@ void run_posix_cpu_timers(struct task_struct *tsk) struct k_itimer *timer, *next; unsigned long flags; - WARN_ON_ONCE(!irqs_disabled()); + lockdep_assert_irqs_disabled(); /* * The fast path checks that there are no expired thread or thread From af0733937317e1e03b60f3af8cf9cd59d665593c Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 6 Nov 2017 16:01:29 +0100 Subject: [PATCH 68/70] netpoll: Use lockdep to assert IRQs are disabled/enabled Use lockdep to check that IRQs are enabled or disabled as expected. This way the sanity check only shows overhead when concurrency correctness debug code is enabled. Signed-off-by: Frederic Weisbecker Acked-by: Thomas Gleixner Cc: David S. Miller Cc: Lai Jiangshan Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Tejun Heo Link: http://lkml.kernel.org/r/1509980490-4285-14-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar --- net/core/netpoll.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/core/netpoll.c b/net/core/netpoll.c index 912731bed7b7..57557a6a950c 100644 --- a/net/core/netpoll.c +++ b/net/core/netpoll.c @@ -334,7 +334,7 @@ void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb, /* It is up to the caller to keep npinfo alive. */ struct netpoll_info *npinfo; - WARN_ON_ONCE(!irqs_disabled()); + lockdep_assert_irqs_disabled(); npinfo = rcu_dereference_bh(np->dev->npinfo); if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { From b04db8e19fc2e9131524dec43057c1b96d5ba3ba Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 6 Nov 2017 16:01:30 +0100 Subject: [PATCH 69/70] rcu: Use lockdep to assert IRQs are disabled/enabled Lockdep now has an integrated IRQs disabled/enabled sanity check. Just use it instead of the ad-hoc RCU version. Signed-off-by: Frederic Weisbecker Acked-by: Thomas Gleixner Acked-by: Paul E. McKenney Cc: David S . Miller Cc: Lai Jiangshan Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Tejun Heo Link: http://lkml.kernel.org/r/1509980490-4285-15-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar --- kernel/rcu/tree.c | 16 ++++++++-------- kernel/rcu/tree_plugin.h | 10 +++++----- 2 files changed, 13 insertions(+), 13 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 3e3650e94ae6..08fa586d7f8c 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -734,7 +734,7 @@ static int rcu_future_needs_gp(struct rcu_state *rsp) int idx = (READ_ONCE(rnp->completed) + 1) & 0x1; int *fp = &rnp->need_future_gp[idx]; - RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_future_needs_gp() invoked with irqs enabled!!!"); + lockdep_assert_irqs_disabled(); return READ_ONCE(*fp); } @@ -746,7 +746,7 @@ static int rcu_future_needs_gp(struct rcu_state *rsp) static bool cpu_needs_another_gp(struct rcu_state *rsp, struct rcu_data *rdp) { - RCU_LOCKDEP_WARN(!irqs_disabled(), "cpu_needs_another_gp() invoked with irqs enabled!!!"); + lockdep_assert_irqs_disabled(); if (rcu_gp_in_progress(rsp)) return false; /* No, a grace period is already in progress. */ if (rcu_future_needs_gp(rsp)) @@ -773,7 +773,7 @@ static void rcu_eqs_enter_common(bool user) struct rcu_data *rdp; struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks); - RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_eqs_enter_common() invoked with irqs enabled!!!"); + lockdep_assert_irqs_disabled(); trace_rcu_dyntick(TPS("Start"), rdtp->dynticks_nesting, 0); if (IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && !user && !is_idle_task(current)) { @@ -840,7 +840,7 @@ static void rcu_eqs_enter(bool user) */ void rcu_idle_enter(void) { - RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_idle_enter() invoked with irqs enabled!!!"); + lockdep_assert_irqs_disabled(); rcu_eqs_enter(false); } @@ -855,7 +855,7 @@ void rcu_idle_enter(void) */ void rcu_user_enter(void) { - RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_user_enter() invoked with irqs enabled!!!"); + lockdep_assert_irqs_disabled(); rcu_eqs_enter(true); } #endif /* CONFIG_NO_HZ_FULL */ @@ -880,7 +880,7 @@ void rcu_irq_exit(void) { struct rcu_dynticks *rdtp; - RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_irq_exit() invoked with irqs enabled!!!"); + lockdep_assert_irqs_disabled(); rdtp = this_cpu_ptr(&rcu_dynticks); /* Page faults can happen in NMI handlers, so check... */ @@ -947,7 +947,7 @@ static void rcu_eqs_exit(bool user) struct rcu_dynticks *rdtp; long long oldval; - RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_eqs_exit() invoked with irqs enabled!!!"); + lockdep_assert_irqs_disabled(); rdtp = this_cpu_ptr(&rcu_dynticks); oldval = rdtp->dynticks_nesting; WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && oldval < 0); @@ -1018,7 +1018,7 @@ void rcu_irq_enter(void) struct rcu_dynticks *rdtp; long long oldval; - RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_irq_enter() invoked with irqs enabled!!!"); + lockdep_assert_irqs_disabled(); rdtp = this_cpu_ptr(&rcu_dynticks); /* Page faults can happen in NMI handlers, so check... */ diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index e012b9be777e..df08e5c8126b 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -325,7 +325,7 @@ static void rcu_preempt_note_context_switch(bool preempt) struct rcu_data *rdp; struct rcu_node *rnp; - RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_preempt_note_context_switch() invoked with interrupts enabled!!!\n"); + lockdep_assert_irqs_disabled(); WARN_ON_ONCE(!preempt && t->rcu_read_lock_nesting > 0); if (t->rcu_read_lock_nesting > 0 && !t->rcu_read_unlock_special.b.blocked) { @@ -1421,7 +1421,7 @@ int rcu_needs_cpu(u64 basemono, u64 *nextevt) struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks); unsigned long dj; - RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_needs_cpu() invoked with irqs enabled!!!"); + lockdep_assert_irqs_disabled(); /* Snapshot to detect later posting of non-lazy callback. */ rdtp->nonlazy_posted_snap = rdtp->nonlazy_posted; @@ -1470,7 +1470,7 @@ static void rcu_prepare_for_idle(void) struct rcu_state *rsp; int tne; - RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_prepare_for_idle() invoked with irqs enabled!!!"); + lockdep_assert_irqs_disabled(); if (rcu_is_nocb_cpu(smp_processor_id())) return; @@ -1525,7 +1525,7 @@ static void rcu_prepare_for_idle(void) */ static void rcu_cleanup_after_idle(void) { - RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_cleanup_after_idle() invoked with irqs enabled!!!"); + lockdep_assert_irqs_disabled(); if (rcu_is_nocb_cpu(smp_processor_id())) return; if (rcu_try_advance_all_cbs()) @@ -2012,7 +2012,7 @@ static bool __maybe_unused rcu_nocb_adopt_orphan_cbs(struct rcu_data *my_rdp, struct rcu_data *rdp, unsigned long flags) { - RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_nocb_adopt_orphan_cbs() invoked with irqs enabled!!!"); + lockdep_assert_irqs_disabled(); if (!rcu_is_nocb_cpu(smp_processor_id())) return false; /* Not NOCBs CPU, caller must migrate CBs. */ __call_rcu_nocb_enqueue(my_rdp, rcu_segcblist_head(&rdp->cblist), From 450cbdd0125cfa5d7bbf9e2a6b6961cc48d29730 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Fri, 27 Oct 2017 19:14:31 +0300 Subject: [PATCH 70/70] locking/x86: Use LOCK ADD for smp_mb() instead of MFENCE MFENCE appears to be way slower than a locked instruction - let's use LOCK ADD unconditionally, as we always did on old 32-bit. Performance testing results: perf stat -r 10 -- ./virtio_ring_0_9 --sleep --host-affinity 0 --guest-affinity 0 Before: 0.922565990 seconds time elapsed ( +- 1.15% ) After: 0.578667024 seconds time elapsed ( +- 1.21% ) i.e. about ~60% faster. Just poking at SP would be the most natural, but if we then read the value from SP, we get a false dependency which will slow us down. This was noted in this article: http://shipilev.net/blog/2014/on-the-fence-with-dependencies/ And is easy to reproduce by sticking a barrier in a small non-inline function. So let's use a negative offset - which avoids this problem since we build with the red zone disabled. For userspace, use an address just below the redzone. The one difference between LOCK ADD and MFENCE is that LOCK ADD does not affect CLFLUSH, previous patches converted all uses of CLFLUSH to call mb(), such that changes to smp_mb() won't affect it. Update mb/rmb/wmb() on 32-bit to use the negative offset, too, for consistency. As a follow-up, it might be worth considering switching users of CLFLUSH to another API (e.g. clflush_mb()?) - we will then be able to convert mb() to smp_mb() again. Also arguably, GCC should switch to use LOCK ADD for __sync_synchronize(). This might be worth pursuing separately. Suggested-by: Andy Lutomirski Signed-off-by: Michael S. Tsirkin Acked-by: Peter Zijlstra Acked-by: Thomas Gleixner Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Paul E. McKenney Cc: qemu-devel@nongnu.org Cc: virtualization@lists.linux-foundation.org Link: http://lkml.kernel.org/r/1509118355-4890-1-git-send-email-mst@redhat.com Signed-off-by: Ingo Molnar --- arch/x86/include/asm/barrier.h | 12 ++++++++---- tools/virtio/ringtest/main.h | 4 ++++ 2 files changed, 12 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/barrier.h b/arch/x86/include/asm/barrier.h index 01727dbc294a..7fb336210e1b 100644 --- a/arch/x86/include/asm/barrier.h +++ b/arch/x86/include/asm/barrier.h @@ -12,11 +12,11 @@ */ #ifdef CONFIG_X86_32 -#define mb() asm volatile(ALTERNATIVE("lock; addl $0,0(%%esp)", "mfence", \ +#define mb() asm volatile(ALTERNATIVE("lock; addl $0,-4(%%esp)", "mfence", \ X86_FEATURE_XMM2) ::: "memory", "cc") -#define rmb() asm volatile(ALTERNATIVE("lock; addl $0,0(%%esp)", "lfence", \ +#define rmb() asm volatile(ALTERNATIVE("lock; addl $0,-4(%%esp)", "lfence", \ X86_FEATURE_XMM2) ::: "memory", "cc") -#define wmb() asm volatile(ALTERNATIVE("lock; addl $0,0(%%esp)", "sfence", \ +#define wmb() asm volatile(ALTERNATIVE("lock; addl $0,-4(%%esp)", "sfence", \ X86_FEATURE_XMM2) ::: "memory", "cc") #else #define mb() asm volatile("mfence":::"memory") @@ -31,7 +31,11 @@ #endif #define dma_wmb() barrier() -#define __smp_mb() mb() +#ifdef CONFIG_X86_32 +#define __smp_mb() asm volatile("lock; addl $0,-4(%%esp)" ::: "memory", "cc") +#else +#define __smp_mb() asm volatile("lock; addl $0,-4(%%rsp)" ::: "memory", "cc") +#endif #define __smp_rmb() dma_rmb() #define __smp_wmb() barrier() #define __smp_store_mb(var, value) do { (void)xchg(&var, value); } while (0) diff --git a/tools/virtio/ringtest/main.h b/tools/virtio/ringtest/main.h index 90b0133004e1..5706e075adf2 100644 --- a/tools/virtio/ringtest/main.h +++ b/tools/virtio/ringtest/main.h @@ -110,11 +110,15 @@ static inline void busy_wait(void) barrier(); } +#if defined(__x86_64__) || defined(__i386__) +#define smp_mb() asm volatile("lock; addl $0,-128(%%rsp)" ::: "memory", "cc") +#else /* * Not using __ATOMIC_SEQ_CST since gcc docs say they are only synchronized * with other __ATOMIC_SEQ_CST calls. */ #define smp_mb() __sync_synchronize() +#endif /* * This abuses the atomic builtins for thread fences, and