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Merge branch 'uaccess' into fixes

This commit is contained in:
Russell King 2015-09-11 19:18:28 +01:00
parent a4a5a7379e 0b61f2c0f3
commit c2172ce230
31 changed files with 398 additions and 139 deletions
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15
arch/arm/Kconfig
View File

@ -1700,6 +1700,21 @@ config HIGHPTE
consumed by page tables. Setting this option will allow
user-space 2nd level page tables to reside in high memory.
config CPU_SW_DOMAIN_PAN
bool "Enable use of CPU domains to implement privileged no-access"
depends on MMU && !ARM_LPAE
default y
help
Increase kernel security by ensuring that normal kernel accesses
are unable to access userspace addresses. This can help prevent
use-after-free bugs becoming an exploitable privilege escalation
by ensuring that magic values (such as LIST_POISON) will always
fault when dereferenced.
CPUs with low-vector mappings use a best-efforts implementation.
Their lower 1MB needs to remain accessible for the vectors, but
the remainder of userspace will become appropriately inaccessible.
config HW_PERF_EVENTS
bool "Enable hardware performance counter support for perf events"
depends on PERF_EVENTS

42
arch/arm/include/asm/assembler.h
View File

@ -445,6 +445,48 @@ THUMB( orr \reg , \reg , #PSR_T_BIT )
#endif
.endm
.macro uaccess_disable, tmp, isb=1
#ifdef CONFIG_CPU_SW_DOMAIN_PAN
/*
* Whenever we re-enter userspace, the domains should always be
* set appropriately.
*/
mov \tmp, #DACR_UACCESS_DISABLE
mcr p15, 0, \tmp, c3, c0, 0 @ Set domain register
.if \isb
instr_sync
.endif
#endif
.endm
.macro uaccess_enable, tmp, isb=1
#ifdef CONFIG_CPU_SW_DOMAIN_PAN
/*
* Whenever we re-enter userspace, the domains should always be
* set appropriately.
*/
mov \tmp, #DACR_UACCESS_ENABLE
mcr p15, 0, \tmp, c3, c0, 0
.if \isb
instr_sync
.endif
#endif
.endm
.macro uaccess_save, tmp
#ifdef CONFIG_CPU_SW_DOMAIN_PAN
mrc p15, 0, \tmp, c3, c0, 0
str \tmp, [sp, #S_FRAME_SIZE]
#endif
.endm
.macro uaccess_restore
#ifdef CONFIG_CPU_SW_DOMAIN_PAN
ldr r0, [sp, #S_FRAME_SIZE]
mcr p15, 0, r0, c3, c0, 0
#endif
.endm
.irp c,,eq,ne,cs,cc,mi,pl,vs,vc,hi,ls,ge,lt,gt,le,hs,lo
.macro ret\c, reg
#if __LINUX_ARM_ARCH__ < 6

57
arch/arm/include/asm/domain.h
View File

@ -12,6 +12,7 @@
#ifndef __ASSEMBLY__
#include <asm/barrier.h>
#include <asm/thread_info.h>
#endif
/*
@ -34,15 +35,14 @@
*/
#ifndef CONFIG_IO_36
#define DOMAIN_KERNEL 0
#define DOMAIN_TABLE 0
#define DOMAIN_USER 1
#define DOMAIN_IO 2
#else
#define DOMAIN_KERNEL 2
#define DOMAIN_TABLE 2
#define DOMAIN_USER 1
#define DOMAIN_IO 0
#endif
#define DOMAIN_VECTORS 3
/*
* Domain types
@ -55,30 +55,65 @@
#define DOMAIN_MANAGER 1
#endif
#define domain_val(dom,type) ((type) << (2*(dom)))
#define domain_mask(dom) ((3) << (2 * (dom)))
#define domain_val(dom,type) ((type) << (2 * (dom)))
#ifdef CONFIG_CPU_SW_DOMAIN_PAN
#define DACR_INIT \
(domain_val(DOMAIN_USER, DOMAIN_NOACCESS) | \
domain_val(DOMAIN_KERNEL, DOMAIN_MANAGER) | \
domain_val(DOMAIN_IO, DOMAIN_CLIENT) | \
domain_val(DOMAIN_VECTORS, DOMAIN_CLIENT))
#else
#define DACR_INIT \
(domain_val(DOMAIN_USER, DOMAIN_CLIENT) | \
domain_val(DOMAIN_KERNEL, DOMAIN_MANAGER) | \
domain_val(DOMAIN_IO, DOMAIN_CLIENT) | \
domain_val(DOMAIN_VECTORS, DOMAIN_CLIENT))
#endif
#define __DACR_DEFAULT \
domain_val(DOMAIN_KERNEL, DOMAIN_CLIENT) | \
domain_val(DOMAIN_IO, DOMAIN_CLIENT) | \
domain_val(DOMAIN_VECTORS, DOMAIN_CLIENT)
#define DACR_UACCESS_DISABLE \
(__DACR_DEFAULT | domain_val(DOMAIN_USER, DOMAIN_NOACCESS))
#define DACR_UACCESS_ENABLE \
(__DACR_DEFAULT | domain_val(DOMAIN_USER, DOMAIN_CLIENT))
#ifndef __ASSEMBLY__
#ifdef CONFIG_CPU_USE_DOMAINS
static inline unsigned int get_domain(void)
{
unsigned int domain;
asm(
"mrc p15, 0, %0, c3, c0 @ get domain"
: "=r" (domain)
: "m" (current_thread_info()->cpu_domain));
return domain;
}
static inline void set_domain(unsigned val)
{
asm volatile(
"mcr p15, 0, %0, c3, c0 @ set domain"
: : "r" (val));
: : "r" (val) : "memory");
isb();
}
#ifdef CONFIG_CPU_USE_DOMAINS
#define modify_domain(dom,type) \
do { \
struct thread_info *thread = current_thread_info(); \
unsigned int domain = thread->cpu_domain; \
domain &= ~domain_val(dom, DOMAIN_MANAGER); \
thread->cpu_domain = domain | domain_val(dom, type); \
set_domain(thread->cpu_domain); \
unsigned int domain = get_domain(); \
domain &= ~domain_mask(dom); \
domain = domain | domain_val(dom, type); \
set_domain(domain); \
} while (0)
#else
static inline void set_domain(unsigned val) { }
static inline void modify_domain(unsigned dom, unsigned type) { }
#endif

19
arch/arm/include/asm/futex.h
View File

@ -22,8 +22,11 @@
#ifdef CONFIG_SMP
#define __futex_atomic_op(insn, ret, oldval, tmp, uaddr, oparg) \
({ \
unsigned int __ua_flags; \
smp_mb(); \
prefetchw(uaddr); \
__ua_flags = uaccess_save_and_enable(); \
__asm__ __volatile__( \
"1: ldrex %1, [%3]\n" \
" " insn "\n" \
@ -34,12 +37,15 @@
__futex_atomic_ex_table("%5") \
: "=&r" (ret), "=&r" (oldval), "=&r" (tmp) \
: "r" (uaddr), "r" (oparg), "Ir" (-EFAULT) \
: "cc", "memory")
: "cc", "memory"); \
uaccess_restore(__ua_flags); \
})
static inline int
futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
u32 oldval, u32 newval)
{
unsigned int __ua_flags;
int ret;
u32 val;
@ -49,6 +55,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
smp_mb();
/* Prefetching cannot fault */
prefetchw(uaddr);
__ua_flags = uaccess_save_and_enable();
__asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n"
"1: ldrex %1, [%4]\n"
" teq %1, %2\n"
@ -61,6 +68,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
: "=&r" (ret), "=&r" (val)
: "r" (oldval), "r" (newval), "r" (uaddr), "Ir" (-EFAULT)
: "cc", "memory");
uaccess_restore(__ua_flags);
smp_mb();
*uval = val;
@ -73,6 +81,8 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
#include <asm/domain.h>
#define __futex_atomic_op(insn, ret, oldval, tmp, uaddr, oparg) \
({ \
unsigned int __ua_flags = uaccess_save_and_enable(); \
__asm__ __volatile__( \
"1: " TUSER(ldr) " %1, [%3]\n" \
" " insn "\n" \
@ -81,12 +91,15 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
__futex_atomic_ex_table("%5") \
: "=&r" (ret), "=&r" (oldval), "=&r" (tmp) \
: "r" (uaddr), "r" (oparg), "Ir" (-EFAULT) \
: "cc", "memory")
: "cc", "memory"); \
uaccess_restore(__ua_flags); \
})
static inline int
futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
u32 oldval, u32 newval)
{
unsigned int __ua_flags;
int ret = 0;
u32 val;
@ -94,6 +107,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
return -EFAULT;
preempt_disable();
__ua_flags = uaccess_save_and_enable();
__asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n"
"1: " TUSER(ldr) " %1, [%4]\n"
" teq %1, %2\n"
@ -103,6 +117,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
: "+r" (ret), "=&r" (val)
: "r" (oldval), "r" (newval), "r" (uaddr), "Ir" (-EFAULT)
: "cc", "memory");
uaccess_restore(__ua_flags);
*uval = val;
preempt_enable();

1
arch/arm/include/asm/pgtable-2level-hwdef.h
View File

@ -23,6 +23,7 @@
#define PMD_PXNTABLE (_AT(pmdval_t, 1) << 2) /* v7 */
#define PMD_BIT4 (_AT(pmdval_t, 1) << 4)
#define PMD_DOMAIN(x) (_AT(pmdval_t, (x)) << 5)
#define PMD_DOMAIN_MASK PMD_DOMAIN(0x0f)
#define PMD_PROTECTION (_AT(pmdval_t, 1) << 9) /* v5 */
/*
* - section

4
arch/arm/include/asm/thread_info.h
View File

@ -25,7 +25,6 @@
struct task_struct;
#include <asm/types.h>
#include <asm/domain.h>
typedef unsigned long mm_segment_t;
@ -74,9 +73,6 @@ struct thread_info {
.flags = 0, \
.preempt_count = INIT_PREEMPT_COUNT, \
.addr_limit = KERNEL_DS, \
.cpu_domain = domain_val(DOMAIN_USER, DOMAIN_MANAGER) | \
domain_val(DOMAIN_KERNEL, DOMAIN_MANAGER) | \
domain_val(DOMAIN_IO, DOMAIN_CLIENT), \
}
#define init_thread_info (init_thread_union.thread_info)

85
arch/arm/include/asm/uaccess.h
View File

@ -49,6 +49,35 @@ struct exception_table_entry
extern int fixup_exception(struct pt_regs *regs);
/*
* These two functions allow hooking accesses to userspace to increase
* system integrity by ensuring that the kernel can not inadvertantly
* perform such accesses (eg, via list poison values) which could then
* be exploited for priviledge escalation.
*/
static inline unsigned int uaccess_save_and_enable(void)
{
#ifdef CONFIG_CPU_SW_DOMAIN_PAN
unsigned int old_domain = get_domain();
/* Set the current domain access to permit user accesses */
set_domain((old_domain & ~domain_mask(DOMAIN_USER)) |
domain_val(DOMAIN_USER, DOMAIN_CLIENT));
return old_domain;
#else
return 0;
#endif
}
static inline void uaccess_restore(unsigned int flags)
{
#ifdef CONFIG_CPU_SW_DOMAIN_PAN
/* Restore the user access mask */
set_domain(flags);
#endif
}
/*
* These two are intentionally not defined anywhere - if the kernel
* code generates any references to them, that's a bug.
@ -165,6 +194,7 @@ extern int __get_user_64t_4(void *);
register typeof(x) __r2 asm("r2"); \
register unsigned long __l asm("r1") = __limit; \
register int __e asm("r0"); \
unsigned int __ua_flags = uaccess_save_and_enable(); \
switch (sizeof(*(__p))) { \
case 1: \
if (sizeof((x)) >= 8) \
@ -192,6 +222,7 @@ extern int __get_user_64t_4(void *);
break; \
default: __e = __get_user_bad(); break; \
} \
uaccess_restore(__ua_flags); \
x = (typeof(*(p))) __r2; \
__e; \
})
@ -224,6 +255,7 @@ extern int __put_user_8(void *, unsigned long long);
register const typeof(*(p)) __user *__p asm("r0") = __tmp_p; \
register unsigned long __l asm("r1") = __limit; \
register int __e asm("r0"); \
unsigned int __ua_flags = uaccess_save_and_enable(); \
switch (sizeof(*(__p))) { \
case 1: \
__put_user_x(__r2, __p, __e, __l, 1); \
@ -239,6 +271,7 @@ extern int __put_user_8(void *, unsigned long long);
break; \
default: __e = __put_user_bad(); break; \
} \
uaccess_restore(__ua_flags); \
__e; \
})
@ -300,14 +333,17 @@ static inline void set_fs(mm_segment_t fs)
do { \
unsigned long __gu_addr = (unsigned long)(ptr); \
unsigned long __gu_val; \
unsigned int __ua_flags; \
__chk_user_ptr(ptr); \
might_fault(); \
__ua_flags = uaccess_save_and_enable(); \
switch (sizeof(*(ptr))) { \
case 1: __get_user_asm_byte(__gu_val, __gu_addr, err); break; \
case 2: __get_user_asm_half(__gu_val, __gu_addr, err); break; \
case 4: __get_user_asm_word(__gu_val, __gu_addr, err); break; \
default: (__gu_val) = __get_user_bad(); \
} \
uaccess_restore(__ua_flags); \
(x) = (__typeof__(*(ptr)))__gu_val; \
} while (0)
@ -381,9 +417,11 @@ do { \
#define __put_user_err(x, ptr, err) \
do { \
unsigned long __pu_addr = (unsigned long)(ptr); \
unsigned int __ua_flags; \
__typeof__(*(ptr)) __pu_val = (x); \
__chk_user_ptr(ptr); \
might_fault(); \
__ua_flags = uaccess_save_and_enable(); \
switch (sizeof(*(ptr))) { \
case 1: __put_user_asm_byte(__pu_val, __pu_addr, err); break; \
case 2: __put_user_asm_half(__pu_val, __pu_addr, err); break; \
@ -391,6 +429,7 @@ do { \
case 8: __put_user_asm_dword(__pu_val, __pu_addr, err); break; \
default: __put_user_bad(); \
} \
uaccess_restore(__ua_flags); \
} while (0)
#define __put_user_asm_byte(x, __pu_addr, err) \
@ -474,11 +513,46 @@ do { \
#ifdef CONFIG_MMU
extern unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n);
extern unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n);
extern unsigned long __must_check __copy_to_user_std(void __user *to, const void *from, unsigned long n);
extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n);
extern unsigned long __must_check __clear_user_std(void __user *addr, unsigned long n);
extern unsigned long __must_check
arm_copy_from_user(void *to, const void __user *from, unsigned long n);
static inline unsigned long __must_check
__copy_from_user(void *to, const void __user *from, unsigned long n)
{
unsigned int __ua_flags = uaccess_save_and_enable();
n = arm_copy_from_user(to, from, n);
uaccess_restore(__ua_flags);
return n;
}
extern unsigned long __must_check
arm_copy_to_user(void __user *to, const void *from, unsigned long n);
extern unsigned long __must_check
__copy_to_user_std(void __user *to, const void *from, unsigned long n);
static inline unsigned long __must_check
__copy_to_user(void __user *to, const void *from, unsigned long n)
{
unsigned int __ua_flags = uaccess_save_and_enable();
n = arm_copy_to_user(to, from, n);
uaccess_restore(__ua_flags);
return n;
}
extern unsigned long __must_check
arm_clear_user(void __user *addr, unsigned long n);
extern unsigned long __must_check
__clear_user_std(void __user *addr, unsigned long n);
static inline unsigned long __must_check
__clear_user(void __user *addr, unsigned long n)
{
unsigned int __ua_flags = uaccess_save_and_enable();
n = arm_clear_user(addr, n);
uaccess_restore(__ua_flags);
return n;
}
#else
#define __copy_from_user(to, from, n) (memcpy(to, (void __force *)from, n), 0)
#define __copy_to_user(to, from, n) (memcpy((void __force *)to, from, n), 0)
@ -511,6 +585,7 @@ static inline unsigned long __must_check clear_user(void __user *to, unsigned lo
return n;
}
/* These are from lib/ code, and use __get_user() and friends */
extern long strncpy_from_user(char *dest, const char __user *src, long count);
extern __must_check long strlen_user(const char __user *str);

6
arch/arm/kernel/armksyms.c
View File

@ -97,9 +97,9 @@ EXPORT_SYMBOL(mmiocpy);
#ifdef CONFIG_MMU
EXPORT_SYMBOL(copy_page);
EXPORT_SYMBOL(__copy_from_user);
EXPORT_SYMBOL(__copy_to_user);
EXPORT_SYMBOL(__clear_user);
EXPORT_SYMBOL(arm_copy_from_user);
EXPORT_SYMBOL(arm_copy_to_user);
EXPORT_SYMBOL(arm_clear_user);
EXPORT_SYMBOL(__get_user_1);
EXPORT_SYMBOL(__get_user_2);

32
arch/arm/kernel/entry-armv.S
View File

@ -149,10 +149,10 @@ ENDPROC(__und_invalid)
#define SPFIX(code...)
#endif
.macro svc_entry, stack_hole=0, trace=1
.macro svc_entry, stack_hole=0, trace=1, uaccess=1
UNWIND(.fnstart )
UNWIND(.save {r0 - pc} )
sub sp, sp, #(S_FRAME_SIZE + \stack_hole - 4)
sub sp, sp, #(S_FRAME_SIZE + 8 + \stack_hole - 4)
#ifdef CONFIG_THUMB2_KERNEL
SPFIX( str r0, [sp] ) @ temporarily saved
SPFIX( mov r0, sp )
@ -167,7 +167,7 @@ ENDPROC(__und_invalid)
ldmia r0, {r3 - r5}
add r7, sp, #S_SP - 4 @ here for interlock avoidance
mov r6, #-1 @ "" "" "" ""
add r2, sp, #(S_FRAME_SIZE + \stack_hole - 4)
add r2, sp, #(S_FRAME_SIZE + 8 + \stack_hole - 4)
SPFIX( addeq r2, r2, #4 )
str r3, [sp, #-4]! @ save the "real" r0 copied
@ from the exception stack
@ -185,6 +185,11 @@ ENDPROC(__und_invalid)
@
stmia r7, {r2 - r6}
uaccess_save r0
.if \uaccess
uaccess_disable r0
.endif
.if \trace
#ifdef CONFIG_TRACE_IRQFLAGS
bl trace_hardirqs_off
@ -194,7 +199,7 @@ ENDPROC(__und_invalid)
.align 5
__dabt_svc:
svc_entry
svc_entry uaccess=0
mov r2, sp
dabt_helper
THUMB( ldr r5, [sp, #S_PSR] ) @ potentially updated CPSR
@ -368,7 +373,7 @@ ENDPROC(__fiq_abt)
#error "sizeof(struct pt_regs) must be a multiple of 8"
#endif
.macro usr_entry, trace=1
.macro usr_entry, trace=1, uaccess=1
UNWIND(.fnstart )
UNWIND(.cantunwind ) @ don't unwind the user space
sub sp, sp, #S_FRAME_SIZE
@ -400,6 +405,10 @@ ENDPROC(__fiq_abt)
ARM( stmdb r0, {sp, lr}^ )
THUMB( store_user_sp_lr r0, r1, S_SP - S_PC )
.if \uaccess
uaccess_disable ip
.endif
@ Enable the alignment trap while in kernel mode
ATRAP( teq r8, r7)
ATRAP( mcrne p15, 0, r8, c1, c0, 0)
@ -435,7 +444,7 @@ ENDPROC(__fiq_abt)
.align 5
__dabt_usr:
usr_entry
usr_entry uaccess=0
kuser_cmpxchg_check
mov r2, sp
dabt_helper
@ -458,7 +467,7 @@ ENDPROC(__irq_usr)
.align 5
__und_usr:
usr_entry
usr_entry uaccess=0
mov r2, r4
mov r3, r5
@ -484,6 +493,8 @@ __und_usr:
1: ldrt r0, [r4]
ARM_BE8(rev r0, r0) @ little endian instruction
uaccess_disable ip
@ r0 = 32-bit ARM instruction which caused the exception
@ r2 = PC value for the following instruction (:= regs->ARM_pc)
@ r4 = PC value for the faulting instruction
@ -518,9 +529,10 @@ __und_usr_thumb:
2: ldrht r5, [r4]
ARM_BE8(rev16 r5, r5) @ little endian instruction
cmp r5, #0xe800 @ 32bit instruction if xx != 0
blo __und_usr_fault_16 @ 16bit undefined instruction
blo __und_usr_fault_16_pan @ 16bit undefined instruction
3: ldrht r0, [r2]
ARM_BE8(rev16 r0, r0) @ little endian instruction
uaccess_disable ip
add r2, r2, #2 @ r2 is PC + 2, make it PC + 4
str r2, [sp, #S_PC] @ it's a 2x16bit instr, update
orr r0, r0, r5, lsl #16
@ -715,6 +727,8 @@ ENDPROC(no_fp)
__und_usr_fault_32:
mov r1, #4
b 1f
__und_usr_fault_16_pan:
uaccess_disable ip
__und_usr_fault_16:
mov r1, #2
1: mov r0, sp
@ -770,6 +784,8 @@ ENTRY(__switch_to)
ldr r4, [r2, #TI_TP_VALUE]
ldr r5, [r2, #TI_TP_VALUE + 4]
#ifdef CONFIG_CPU_USE_DOMAINS
mrc p15, 0, r6, c3, c0, 0 @ Get domain register
str r6, [r1, #TI_CPU_DOMAIN] @ Save old domain register
ldr r6, [r2, #TI_CPU_DOMAIN]
#endif
switch_tls r1, r4, r5, r3, r7

2
arch/arm/kernel/entry-common.S
View File

@ -174,6 +174,8 @@ ENTRY(vector_swi)
USER( ldr scno, [lr, #-4] ) @ get SWI instruction
#endif
uaccess_disable tbl
adr tbl, sys_call_table @ load syscall table pointer
#if defined(CONFIG_OABI_COMPAT)

112
arch/arm/kernel/entry-header.S
View File

@ -196,7 +196,7 @@
msr cpsr_c, \rtemp @ switch back to the SVC mode
.endm
#ifndef CONFIG_THUMB2_KERNEL
.macro svc_exit, rpsr, irq = 0
.if \irq != 0
@ IRQs already off
@ -215,6 +215,10 @@
blne trace_hardirqs_off
#endif
.endif
uaccess_restore
#ifndef CONFIG_THUMB2_KERNEL
@ ARM mode SVC restore
msr spsr_cxsf, \rpsr
#if defined(CONFIG_CPU_V6) || defined(CONFIG_CPU_32v6K)
@ We must avoid clrex due to Cortex-A15 erratum #830321
@ -222,6 +226,20 @@
strex r1, r2, [r0] @ clear the exclusive monitor
#endif
ldmia sp, {r0 - pc}^ @ load r0 - pc, cpsr
#else
@ Thumb mode SVC restore
ldr lr, [sp, #S_SP] @ top of the stack
ldrd r0, r1, [sp, #S_LR] @ calling lr and pc
@ We must avoid clrex due to Cortex-A15 erratum #830321
strex r2, r1, [sp, #S_LR] @ clear the exclusive monitor
stmdb lr!, {r0, r1, \rpsr} @ calling lr and rfe context
ldmia sp, {r0 - r12}
mov sp, lr
ldr lr, [sp], #4
rfeia sp!
#endif
.endm
@
@ -241,6 +259,9 @@
@ on the stack remains correct).
@
.macro svc_exit_via_fiq
uaccess_restore
#ifndef CONFIG_THUMB2_KERNEL
@ ARM mode restore
mov r0, sp
ldmib r0, {r1 - r14} @ abort is deadly from here onward (it will
@ clobber state restored below)
@ -250,9 +271,27 @@
msr spsr_cxsf, r9
ldr r0, [r0, #S_R0]
ldmia r8, {pc}^
#else
@ Thumb mode restore
add r0, sp, #S_R2
ldr lr, [sp, #S_LR]
ldr sp, [sp, #S_SP] @ abort is deadly from here onward (it will
@ clobber state restored below)
ldmia r0, {r2 - r12}
mov r1, #FIQ_MODE | PSR_I_BIT | PSR_F_BIT
msr cpsr_c, r1
sub r0, #S_R2
add r8, r0, #S_PC
ldmia r0, {r0 - r1}
rfeia r8
#endif
.endm
.macro restore_user_regs, fast = 0, offset = 0
uaccess_enable r1, isb=0
#ifndef CONFIG_THUMB2_KERNEL
@ ARM mode restore
mov r2, sp
ldr r1, [r2, #\offset + S_PSR] @ get calling cpsr
ldr lr, [r2, #\offset + S_PC]! @ get pc
@ -270,72 +309,16 @@
@ after ldm {}^
add sp, sp, #\offset + S_FRAME_SIZE
movs pc, lr @ return & move spsr_svc into cpsr
.endm
#else /* CONFIG_THUMB2_KERNEL */
.macro svc_exit, rpsr, irq = 0
.if \irq != 0
@ IRQs already off
#ifdef CONFIG_TRACE_IRQFLAGS
@ The parent context IRQs must have been enabled to get here in
@ the first place, so there's no point checking the PSR I bit.
bl trace_hardirqs_on
#endif
.else
@ IRQs off again before pulling preserved data off the stack
disable_irq_notrace
#ifdef CONFIG_TRACE_IRQFLAGS
tst \rpsr, #PSR_I_BIT
bleq trace_hardirqs_on
tst \rpsr, #PSR_I_BIT
blne trace_hardirqs_off
#endif
.endif
ldr lr, [sp, #S_SP] @ top of the stack
ldrd r0, r1, [sp, #S_LR] @ calling lr and pc
@ We must avoid clrex due to Cortex-A15 erratum #830321
strex r2, r1, [sp, #S_LR] @ clear the exclusive monitor
stmdb lr!, {r0, r1, \rpsr} @ calling lr and rfe context
ldmia sp, {r0 - r12}
mov sp, lr
ldr lr, [sp], #4
rfeia sp!
.endm
@
@ svc_exit_via_fiq - like svc_exit but switches to FIQ mode before exit
@
@ For full details see non-Thumb implementation above.
@
.macro svc_exit_via_fiq
add r0, sp, #S_R2
ldr lr, [sp, #S_LR]
ldr sp, [sp, #S_SP] @ abort is deadly from here onward (it will
@ clobber state restored below)
ldmia r0, {r2 - r12}
mov r1, #FIQ_MODE | PSR_I_BIT | PSR_F_BIT
msr cpsr_c, r1
sub r0, #S_R2
add r8, r0, #S_PC
ldmia r0, {r0 - r1}
rfeia r8
.endm
#ifdef CONFIG_CPU_V7M
/*
* Note we don't need to do clrex here as clearing the local monitor is
* part of each exception entry and exit sequence.
*/
.macro restore_user_regs, fast = 0, offset = 0
#elif defined(CONFIG_CPU_V7M)
@ V7M restore.
@ Note that we don't need to do clrex here as clearing the local
@ monitor is part of the exception entry and exit sequence.
.if \offset
add sp, #\offset
.endif
v7m_exception_slow_exit ret_r0 = \fast
.endm
#else /* ifdef CONFIG_CPU_V7M */
.macro restore_user_regs, fast = 0, offset = 0
#else
@ Thumb mode restore
mov r2, sp
load_user_sp_lr r2, r3, \offset + S_SP @ calling sp, lr
ldr r1, [sp, #\offset + S_PSR] @ get calling cpsr
@ -353,9 +336,8 @@
.endif
add sp, sp, #S_FRAME_SIZE - S_SP
movs pc, lr @ return & move spsr_svc into cpsr
.endm
#endif /* ifdef CONFIG_CPU_V7M / else */
#endif /* !CONFIG_THUMB2_KERNEL */
.endm
/*
* Context tracking subsystem. Used to instrument transitions

5
arch/arm/kernel/head.S
View File

@ -464,10 +464,7 @@ __enable_mmu:
#ifdef CONFIG_ARM_LPAE
mcrr p15, 0, r4, r5, c2 @ load TTBR0
#else
mov r5, #(domain_val(DOMAIN_USER, DOMAIN_MANAGER) | \
domain_val(DOMAIN_KERNEL, DOMAIN_MANAGER) | \
domain_val(DOMAIN_TABLE, DOMAIN_MANAGER) | \
domain_val(DOMAIN_IO, DOMAIN_CLIENT))
mov r5, #DACR_INIT
mcr p15, 0, r5, c3, c0, 0 @ load domain access register
mcr p15, 0, r4, c2, c0, 0 @ load page table pointer
#endif

51
arch/arm/kernel/process.c
View File

@ -129,12 +129,36 @@ void __show_regs(struct pt_regs *regs)
buf[4] = '\0';
#ifndef CONFIG_CPU_V7M
printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n",
buf, interrupts_enabled(regs) ? "n" : "ff",
fast_interrupts_enabled(regs) ? "n" : "ff",
processor_modes[processor_mode(regs)],
isa_modes[isa_mode(regs)],
get_fs() == get_ds() ? "kernel" : "user");
{
unsigned int domain = get_domain();
const char *segment;
#ifdef CONFIG_CPU_SW_DOMAIN_PAN
/*
* Get the domain register for the parent context. In user
* mode, we don't save the DACR, so lets use what it should
* be. For other modes, we place it after the pt_regs struct.
*/
if (user_mode(regs))
domain = DACR_UACCESS_ENABLE;
else
domain = *(unsigned int *)(regs + 1);
#endif
if ((domain & domain_mask(DOMAIN_USER)) ==
domain_val(DOMAIN_USER, DOMAIN_NOACCESS))
segment = "none";
else if (get_fs() == get_ds())
segment = "kernel";
else
segment = "user";
printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n",
buf, interrupts_enabled(regs) ? "n" : "ff",
fast_interrupts_enabled(regs) ? "n" : "ff",
processor_modes[processor_mode(regs)],
isa_modes[isa_mode(regs)], segment);
}
#else
printk("xPSR: %08lx\n", regs->ARM_cpsr);
#endif
@ -146,10 +170,9 @@ void __show_regs(struct pt_regs *regs)
buf[0] = '\0';
#ifdef CONFIG_CPU_CP15_MMU
{
unsigned int transbase, dac;
unsigned int transbase, dac = get_domain();
asm("mrc p15, 0, %0, c2, c0\n\t"
"mrc p15, 0, %1, c3, c0\n"
: "=r" (transbase), "=r" (dac));
: "=r" (transbase));
snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x",
transbase, dac);
}
@ -210,6 +233,16 @@ copy_thread(unsigned long clone_flags, unsigned long stack_start,
memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
#ifdef CONFIG_CPU_USE_DOMAINS
/*
* Copy the initial value of the domain access control register
* from the current thread: thread->addr_limit will have been
* copied from the current thread via setup_thread_stack() in
* kernel/fork.c
*/
thread->cpu_domain = get_domain();
#endif
if (likely(!(p->flags & PF_KTHREAD))) {
*childregs = *current_pt_regs();
childregs->ARM_r0 = 0;

3
arch/arm/kernel/swp_emulate.c
View File

@ -141,11 +141,14 @@ static int emulate_swpX(unsigned int address, unsigned int *data,
while (1) {
unsigned long temp;
unsigned int __ua_flags;
__ua_flags = uaccess_save_and_enable();
if (type == TYPE_SWPB)
__user_swpb_asm(*data, address, res, temp);
else
__user_swp_asm(*data, address, res, temp);
uaccess_restore(__ua_flags);
if (likely(res != -EAGAIN) || signal_pending(current))
break;

1
arch/arm/kernel/traps.c
View File

@ -870,7 +870,6 @@ void __init early_trap_init(void *vectors_base)
kuser_init(vectors_base);
flush_icache_range(vectors, vectors + PAGE_SIZE * 2);
modify_domain(DOMAIN_USER, DOMAIN_CLIENT);
#else /* ifndef CONFIG_CPU_V7M */
/*
* on V7-M there is no need to copy the vector table to a dedicated

6
arch/arm/lib/clear_user.S
View File

@ -12,14 +12,14 @@
.text
/* Prototype: int __clear_user(void *addr, size_t sz)
/* Prototype: unsigned long arm_clear_user(void *addr, size_t sz)
* Purpose : clear some user memory
* Params : addr - user memory address to clear
* : sz - number of bytes to clear
* Returns : number of bytes NOT cleared
*/
ENTRY(__clear_user_std)
WEAK(__clear_user)
WEAK(arm_clear_user)
stmfd sp!, {r1, lr}
mov r2, #0
cmp r1, #4
@ -44,7 +44,7 @@ WEAK(__clear_user)
USER( strnebt r2, [r0])
mov r0, #0
ldmfd sp!, {r1, pc}
ENDPROC(__clear_user)
ENDPROC(arm_clear_user)
ENDPROC(__clear_user_std)
.pushsection .text.fixup,"ax"

6
arch/arm/lib/copy_from_user.S
View File

@ -17,7 +17,7 @@
/*
* Prototype:
*
* size_t __copy_from_user(void *to, const void *from, size_t n)
* size_t arm_copy_from_user(void *to, const void *from, size_t n)
*
* Purpose:
*
@ -89,11 +89,11 @@
.text
ENTRY(__copy_from_user)
ENTRY(arm_copy_from_user)
#include "copy_template.S"
ENDPROC(__copy_from_user)
ENDPROC(arm_copy_from_user)
.pushsection .fixup,"ax"
.align 0

6
arch/arm/lib/copy_to_user.S
View File

@ -17,7 +17,7 @@
/*
* Prototype:
*
* size_t __copy_to_user(void *to, const void *from, size_t n)
* size_t arm_copy_to_user(void *to, const void *from, size_t n)
*
* Purpose:
*
@ -93,11 +93,11 @@
.text
ENTRY(__copy_to_user_std)
WEAK(__copy_to_user)
WEAK(arm_copy_to_user)
#include "copy_template.S"
ENDPROC(__copy_to_user)
ENDPROC(arm_copy_to_user)
ENDPROC(__copy_to_user_std)
.pushsection .text.fixup,"ax"

14
arch/arm/lib/csumpartialcopyuser.S
View File

@ -17,6 +17,19 @@
.text
#ifdef CONFIG_CPU_SW_DOMAIN_PAN
.macro save_regs
mrc p15, 0, ip, c3, c0, 0
stmfd sp!, {r1, r2, r4 - r8, ip, lr}
uaccess_enable ip
.endm
.macro load_regs
ldmfd sp!, {r1, r2, r4 - r8, ip, lr}
mcr p15, 0, ip, c3, c0, 0
ret lr
.endm
#else
.macro save_regs
stmfd sp!, {r1, r2, r4 - r8, lr}
.endm
@ -24,6 +37,7 @@
.macro load_regs
ldmfd sp!, {r1, r2, r4 - r8, pc}
.endm
#endif
.macro load1b, reg1
ldrusr \reg1, r0, 1

4
arch/arm/lib/uaccess_with_memcpy.c
View File

@ -136,7 +136,7 @@ __copy_to_user_memcpy(void __user *to, const void *from, unsigned long n)
}
unsigned long
__copy_to_user(void __user *to, const void *from, unsigned long n)
arm_copy_to_user(void __user *to, const void *from, unsigned long n)
{
/*
* This test is stubbed out of the main function above to keep
@ -190,7 +190,7 @@ __clear_user_memset(void __user *addr, unsigned long n)
return n;
}
unsigned long __clear_user(void __user *addr, unsigned long n)
unsigned long arm_clear_user(void __user *addr, unsigned long n)
{
/* See rational for this in __copy_to_user() above. */
if (n < 64)

1
arch/arm/mm/abort-ev4.S
View File

@ -19,6 +19,7 @@ ENTRY(v4_early_abort)
mrc p15, 0, r1, c5, c0, 0 @ get FSR
mrc p15, 0, r0, c6, c0, 0 @ get FAR
ldr r3, [r4] @ read aborted ARM instruction
uaccess_disable ip @ disable userspace access
bic r1, r1, #1 << 11 | 1 << 10 @ clear bits 11 and 10 of FSR
tst r3, #1 << 20 @ L = 1 -> write?
orreq r1, r1, #1 << 11 @ yes.

4
arch/arm/mm/abort-ev5t.S
View File

@ -21,8 +21,10 @@ ENTRY(v5t_early_abort)
mrc p15, 0, r0, c6, c0, 0 @ get FAR
do_thumb_abort fsr=r1, pc=r4, psr=r5, tmp=r3
ldreq r3, [r4] @ read aborted ARM instruction
uaccess_disable ip @ disable user access
bic r1, r1, #1 << 11 @ clear bits 11 of FSR
do_ldrd_abort tmp=ip, insn=r3
teq_ldrd tmp=ip, insn=r3 @ insn was LDRD?
beq do_DataAbort @ yes
tst r3, #1 << 20 @ check write
orreq r1, r1, #1 << 11
b do_DataAbort

4
arch/arm/mm/abort-ev5tj.S
View File

@ -24,7 +24,9 @@ ENTRY(v5tj_early_abort)
bne do_DataAbort
do_thumb_abort fsr=r1, pc=r4, psr=r5, tmp=r3
ldreq r3, [r4] @ read aborted ARM instruction
do_ldrd_abort tmp=ip, insn=r3
uaccess_disable ip @ disable userspace access
teq_ldrd tmp=ip, insn=r3 @ insn was LDRD?
beq do_DataAbort @ yes
tst r3, #1 << 20 @ L = 0 -> write
orreq r1, r1, #1 << 11 @ yes.
b do_DataAbort

8
arch/arm/mm/abort-ev6.S
View File

@ -26,16 +26,18 @@ ENTRY(v6_early_abort)
ldr ip, =0x4107b36
mrc p15, 0, r3, c0, c0, 0 @ get processor id
teq ip, r3, lsr #4 @ r0 ARM1136?
bne do_DataAbort
bne 1f
tst r5, #PSR_J_BIT @ Java?
tsteq r5, #PSR_T_BIT @ Thumb?
bne do_DataAbort
bne 1f
bic r1, r1, #1 << 11 @ clear bit 11 of FSR
ldr r3, [r4] @ read aborted ARM instruction
ARM_BE8(rev r3, r3)
do_ldrd_abort tmp=ip, insn=r3
teq_ldrd tmp=ip, insn=r3 @ insn was LDRD?
beq 1f @ yes
tst r3, #1 << 20 @ L = 0 -> write
orreq r1, r1, #1 << 11 @ yes.
#endif
1: uaccess_disable ip @ disable userspace access
b do_DataAbort

1
arch/arm/mm/abort-ev7.S
View File

@ -15,6 +15,7 @@
ENTRY(v7_early_abort)
mrc p15, 0, r1, c5, c0, 0 @ get FSR
mrc p15, 0, r0, c6, c0, 0 @ get FAR
uaccess_disable ip @ disable userspace access
/*
* V6 code adjusts the returned DFSR.

2
arch/arm/mm/abort-lv4t.S
View File

@ -26,6 +26,7 @@ ENTRY(v4t_late_abort)
#endif
bne .data_thumb_abort
ldr r8, [r4] @ read arm instruction
uaccess_disable ip @ disable userspace access
tst r8, #1 << 20 @ L = 1 -> write?
orreq r1, r1, #1 << 11 @ yes.
and r7, r8, #15 << 24
@ -155,6 +156,7 @@ ENTRY(v4t_late_abort)
.data_thumb_abort:
ldrh r8, [r4] @ read instruction
uaccess_disable ip @ disable userspace access
tst r8, #1 << 11 @ L = 1 -> write?
orreq r1, r1, #1 << 8 @ yes
and r7, r8, #15 << 12

14
arch/arm/mm/abort-macro.S
View File

@ -13,6 +13,7 @@
tst \psr, #PSR_T_BIT
beq not_thumb
ldrh \tmp, [\pc] @ Read aborted Thumb instruction
uaccess_disable ip @ disable userspace access
and \tmp, \tmp, # 0xfe00 @ Mask opcode field
cmp \tmp, # 0x5600 @ Is it ldrsb?
orreq \tmp, \tmp, #1 << 11 @ Set L-bit if yes
@ -29,12 +30,9 @@ not_thumb:
* [7:4] == 1101
* [20] == 0
*/
.macro do_ldrd_abort, tmp, insn
tst \insn, #0x0e100000 @ [27:25,20] == 0
bne not_ldrd
and \tmp, \insn, #0x000000f0 @ [7:4] == 1101
cmp \tmp, #0x000000d0
beq do_DataAbort
not_ldrd:
.macro teq_ldrd, tmp, insn
mov \tmp, #0x0e100000
orr \tmp, #0x000000f0
and \tmp, \insn, \tmp
teq \tmp, #0x000000d0
.endm

4
arch/arm/mm/mmu.c
View File

@ -291,13 +291,13 @@ static struct mem_type mem_types[] = {
.prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
L_PTE_RDONLY,
.prot_l1 = PMD_TYPE_TABLE,
.domain = DOMAIN_USER,
.domain = DOMAIN_VECTORS,
},
[MT_HIGH_VECTORS] = {
.prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
L_PTE_USER | L_PTE_RDONLY,
.prot_l1 = PMD_TYPE_TABLE,
.domain = DOMAIN_USER,
.domain = DOMAIN_VECTORS,
},
[MT_MEMORY_RWX] = {
.prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY,

10
arch/arm/mm/pgd.c
View File

@ -84,6 +84,16 @@ pgd_t *pgd_alloc(struct mm_struct *mm)
if (!new_pte)
goto no_pte;
#ifndef CONFIG_ARM_LPAE
/*
* Modify the PTE pointer to have the correct domain. This
* needs to be the vectors domain to avoid the low vectors
* being unmapped.
*/
pmd_val(*new_pmd) &= ~PMD_DOMAIN_MASK;
pmd_val(*new_pmd) |= PMD_DOMAIN(DOMAIN_VECTORS);
#endif
init_pud = pud_offset(init_pgd, 0);
init_pmd = pmd_offset(init_pud, 0);
init_pte = pte_offset_map(init_pmd, 0);

3
arch/arm/nwfpe/entry.S
View File

@ -95,9 +95,10 @@ emulate:
reteq r4 @ no, return failure
next:
uaccess_enable r3
.Lx1: ldrt r6, [r5], #4 @ get the next instruction and
@ increment PC
uaccess_disable r3
and r2, r6, #0x0F000000 @ test for FP insns
teq r2, #0x0C000000
teqne r2, #0x0D000000

15
arch/arm/xen/hypercall.S
View File

@ -98,8 +98,23 @@ ENTRY(privcmd_call)
mov r1, r2
mov r2, r3
ldr r3, [sp, #8]
/*
* Privcmd calls are issued by the userspace. We need to allow the
* kernel to access the userspace memory before issuing the hypercall.
*/
uaccess_enable r4
/* r4 is loaded now as we use it as scratch register before */
ldr r4, [sp, #4]
__HVC(XEN_IMM)
/*
* Disable userspace access from kernel. This is fine to do it
* unconditionally as no set_fs(KERNEL_DS)/set_fs(get_ds()) is
* called before.
*/
uaccess_disable r4
ldm sp!, {r4}
ret lr
ENDPROC(privcmd_call);