Pull x86 fix from Peter Anvin:
"A single fix to not invoke the espfix code on Xen PV, as it turns out
to oops the guest when invoked after all. This patch leaves some
amount of dead code, in particular unnecessary initialization of the
espfix stacks when they won't be used, but in the interest of keeping
the patch minimal that cleanup can wait for the next cycle"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86_64/entry/xen: Do not invoke espfix64 on Xen
often during boot with Ubuntu 14.04 PV guests.
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Merge tag 'stable/for-linus-3.16-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull Xen fix from David Vrabel:
"Fix BUG when trying to expand the grant table. This seems to occur
often during boot with Ubuntu 14.04 PV guests"
* tag 'stable/for-linus-3.16-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
x86/xen: safely map and unmap grant frames when in atomic context
arch_gnttab_map_frames() and arch_gnttab_unmap_frames() are called in
atomic context but were calling alloc_vm_area() which might sleep.
Also, if a driver attempts to allocate a grant ref from an interrupt
and the table needs expanding, then the CPU may already by in lazy MMU
mode and apply_to_page_range() will BUG when it tries to re-enable
lazy MMU mode.
These two functions are only used in PV guests.
Introduce arch_gnttab_init() to allocates the virtual address space in
advance.
Avoid the use of apply_to_page_range() by using saving and using the
array of PTE addresses from the alloc_vm_area() call (which ensures
that the required page tables are pre-allocated).
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This moves the espfix64 logic into native_iret. To make this work,
it gets rid of the native patch for INTERRUPT_RETURN:
INTERRUPT_RETURN on native kernels is now 'jmp native_iret'.
This changes the 16-bit SS behavior on Xen from OOPSing to leaking
some bits of the Xen hypervisor's RSP (I think).
[ hpa: this is a nonzero cost on native, but probably not enough to
measure. Xen needs to fix this in their own code, probably doing
something equivalent to espfix64. ]
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/7b8f1d8ef6597cb16ae004a43c56980a7de3cf94.1406129132.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org>
Pull perf fixes from Thomas Gleixner:
"A bunch of fixes for perf and kprobes:
- revert a commit that caused a perf group regression
- silence dmesg spam
- fix kprobe probing errors on ia64 and ppc64
- filter kprobe faults from userspace
- lockdep fix for perf exit path
- prevent perf #GP in KVM guest
- correct perf event and filters"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
kprobes: Fix "Failed to find blacklist" probing errors on ia64 and ppc64
kprobes/x86: Don't try to resolve kprobe faults from userspace
perf/x86/intel: Avoid spamming kernel log for BTS buffer failure
perf/x86/intel: Protect LBR and extra_regs against KVM lying
perf: Fix lockdep warning on process exit
perf/x86/intel/uncore: Fix SNB-EP/IVT Cbox filter mappings
perf/x86/intel: Use proper dTLB-load-misses event on IvyBridge
perf: Revert ("perf: Always destroy groups on exit")
Pull x86 fixes from Peter Anvin:
"A couple of crash fixes, plus a fix that on 32 bits would cause a
missing -ENOSYS for nonexistent system calls"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, cpu: Fix cache topology for early P4-SMT
x86_32, entry: Store badsys error code in %eax
x86, MCE: Robustify mcheck_init_device
This fix was necessary after
9c15a24b03 ("x86/mce: Improve mcheck_init_device() error handling")
went in. What this patch did was, among others, check the return value
of misc_register and exit early if it encountered an error. Original
code sloppily didn't do that.
However,
cef12ee52b ("xen/mce: Add mcelog support for Xen platform")
made it so that xen's init routine xen_late_init_mcelog runs first. This
was needed for the xen mcelog device which is supposed to be independent
from the baremetal one.
Initially it was reported that misc_register() fails often on xen and
that's why it needed fixing. However, it is *supposed* to fail by
design, when running in dom0 so that the xen mcelog device file gets
registered first.
And *then* you need the notifier *not* unregistered on the error path so
that the timer does get deleted properly in the CPU hotplug notifier.
Btw, this fix is needed also on baremetal in the unlikely event that
misc_register(&mce_chrdev_device) fails there too.
I was unsure whether to rush it in now and decided to delay it to 3.17.
However, xen people wanted it promoted as it breaks xen when doing cpu
hotplug there. So, after a bit of simmering in tip/master for initial
smoke testing, let's move it to 3.16. It fixes a semi-regression which
got introduced in 3.16 so no need for stable tagging.
tip/x86/ras contains that exact same commit but we can't remove it
there as it is not the last one. It won't cause any merge issues, as I
confirmed locally but I should state here the special situation of this
one fix explicitly anyway.
Thanks.
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x86: Merge tag 'ras_urgent' into x86/urgent
Promote one fix for 3.16
This fix was necessary after
9c15a24b03 ("x86/mce: Improve mcheck_init_device() error handling")
went in. What this patch did was, among others, check the return value
of misc_register and exit early if it encountered an error. Original
code sloppily didn't do that.
However,
cef12ee52b ("xen/mce: Add mcelog support for Xen platform")
made it so that xen's init routine xen_late_init_mcelog runs first. This
was needed for the xen mcelog device which is supposed to be independent
from the baremetal one.
Initially it was reported that misc_register() fails often on xen and
that's why it needed fixing. However, it is *supposed* to fail by
design, when running in dom0 so that the xen mcelog device file gets
registered first.
And *then* you need the notifier *not* unregistered on the error path so
that the timer does get deleted properly in the CPU hotplug notifier.
Btw, this fix is needed also on baremetal in the unlikely event that
misc_register(&mce_chrdev_device) fails there too.
I was unsure whether to rush it in now and decided to delay it to 3.17.
However, xen people wanted it promoted as it breaks xen when doing cpu
hotplug there. So, after a bit of simmering in tip/master for initial
smoke testing, let's move it to 3.16. It fixes a semi-regression which
got introduced in 3.16 so no need for stable tagging.
tip/x86/ras contains that exact same commit but we can't remove it
there as it is not the last one. It won't cause any merge issues, as I
confirmed locally but I should state here the special situation of this
one fix explicitly anyway.
Thanks.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
P4 systems with cpuid level < 4 can have SMT, but the cache topology
description available (cpuid2) does not include SMP information.
Now we know that SMT shares all cache levels, and therefore we can
mark all available cache levels as shared.
We do this by setting cpu_llc_id to ->phys_proc_id, since that's
the same for each SMT thread. We can do this unconditional since if
there's no SMT its still true, the one CPU shares cache with only
itself.
This fixes a problem where such CPUs report an incorrect LLC CPU mask.
This in turn fixes a crash in the scheduler where the topology was
build wrong, it assumes the LLC mask to include at least the SMT CPUs.
Cc: Josh Boyer <jwboyer@redhat.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Tested-by: Bruno Wolff III <bruno@wolff.to>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140722133514.GM12054@laptop.lan
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Commit 554086d ("x86_32, entry: Do syscall exit work on badsys
(CVE-2014-4508)") introduced a regression in the x86_32 syscall entry
code, resulting in syscall() not returning proper errors for undefined
syscalls on CPUs supporting the sysenter feature.
The following code:
> int result = syscall(666);
> printf("result=%d errno=%d error=%s\n", result, errno, strerror(errno));
results in:
> result=666 errno=0 error=Success
Obviously, the syscall return value is the called syscall number, but it
should have been an ENOSYS error. When run under ptrace it behaves
correctly, which makes it hard to debug in the wild:
> result=-1 errno=38 error=Function not implemented
The %eax register is the return value register. For debugging via ptrace
the syscall entry code stores the complete register context on the
stack. The badsys handlers only store the ENOSYS error code in the
ptrace register set and do not set %eax like a regular syscall handler
would. The old resume_userspace call chain contains code that clobbers
%eax and it restores %eax from the ptrace registers afterwards. The same
goes for the ptrace-enabled call chain. When ptrace is not used, the
syscall return value is the passed-in syscall number from the untouched
%eax register.
Use %eax as the return value register in syscall_badsys and
sysenter_badsys, like a real syscall handler does, and have the caller
push the value onto the stack for ptrace access.
Signed-off-by: Sven Wegener <sven.wegener@stealer.net>
Link: http://lkml.kernel.org/r/alpine.LNX.2.11.1407221022380.31021@titan.int.lan.stealer.net
Reviewed-and-tested-by: Andy Lutomirski <luto@amacapital.net>
Cc: <stable@vger.kernel.org> # If 554086d is backported
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
an x86 change too and it is a regression from 3.14. As it only affects
nested virtualization and there were other changes in this area in 3.16,
I am not nominating it for 3.15-stable.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
"These are mostly PPC changes for 3.16-new things. However, there is
an x86 change too and it is a regression from 3.14. As it only
affects nested virtualization and there were other changes in this
area in 3.16, I am not nominating it for 3.15-stable"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: x86: Check for nested events if there is an injectable interrupt
KVM: PPC: RTAS: Do byte swaps explicitly
KVM: PPC: Book3S PR: Fix ABIv2 on LE
KVM: PPC: Assembly functions exported to modules need _GLOBAL_TOC()
PPC: Add _GLOBAL_TOC for 32bit
KVM: PPC: BOOK3S: HV: Use base page size when comparing against slb value
KVM: PPC: Book3E: Unlock mmu_lock when setting caching atttribute
BorisO reports that misc_register() fails often on xen. The current code
unregisters the CPU hotplug notifier in that case. If then a CPU is
offlined and onlined back again, we end up with a second timer running
on that CPU, leading to soft lockups and system hangs.
So let's leave the hotcpu notifier always registered - even if
mce_device_create failed for some cores and never unreg it so that we
can deal with the timer handling accordingly.
Reported-and-Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: http://lkml.kernel.org/r/1403274493-1371-1-git-send-email-boris.ostrovsky@oracle.com
Signed-off-by: Borislav Petkov <bp@suse.de>
Pull locking fixes from Thomas Gleixner:
"The locking department delivers:
- A rather large and intrusive bundle of fixes to address serious
performance regressions introduced by the new rwsem / mcs
technology. Simpler solutions have been discussed, but they would
have been ugly bandaids with more risk than doing the right thing.
- Make the rwsem spin on owner technology opt-in for architectures
and enable it only on the known to work ones.
- A few fixes to the lockdep userspace library"
* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/rwsem: Add CONFIG_RWSEM_SPIN_ON_OWNER
locking/mutex: Disable optimistic spinning on some architectures
locking/rwsem: Reduce the size of struct rw_semaphore
locking/rwsem: Rename 'activity' to 'count'
locking/spinlocks/mcs: Micro-optimize osq_unlock()
locking/spinlocks/mcs: Introduce and use init macro and function for osq locks
locking/spinlocks/mcs: Convert osq lock to atomic_t to reduce overhead
locking/spinlocks/mcs: Rename optimistic_spin_queue() to optimistic_spin_node()
locking/rwsem: Allow conservative optimistic spinning when readers have lock
tools/liblockdep: Account for bitfield changes in lockdeps lock_acquire
tools/liblockdep: Remove debug print left over from development
tools/liblockdep: Fix comparison of a boolean value with a value of 2
Pull x86 fixes from Peter Anvin:
"A couple of key fixes and a few less critical ones. The main ones
are:
- add a .bss section to the PE/COFF headers when building with EFI
stub
- invoke the correct paravirt magic when building the espfix page
tables
Unfortunately both of these areas also have at least one additional
fix each still in thie pipeline, but which are not yet ready to push"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Remove unused variable "polling"
x86/espfix/xen: Fix allocation of pages for paravirt page tables
x86/efi: Include a .bss section within the PE/COFF headers
efi: fdt: Do not report an error during boot if UEFI is not available
efi/arm64: efistub: remove local copy of linux_banner
Pull perf fixes from Ingo Molnar:
"Tooling fixes and an Intel PMU driver fixlet"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Do not allow optimized switch for non-cloned events
perf/x86/intel: ignore CondChgd bit to avoid false NMI handling
perf symbols: Get kernel start address by symbol name
perf tools: Fix segfault in cumulative.callchain report
The optimistic spin code assumes regular stores and cmpxchg() play nice;
this is found to not be true for at least: parisc, sparc32, tile32,
metag-lock1, arc-!llsc and hexagon.
There is further wreckage, but this in particular seemed easy to
trigger, so blacklist this.
Opt in for known good archs.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: David Miller <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: James Bottomley <James.Bottomley@hansenpartnership.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Jason Low <jason.low2@hp.com>
Cc: Waiman Long <waiman.long@hp.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: John David Anglin <dave.anglin@bell.net>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Cc: stable@vger.kernel.org
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: sparclinux@vger.kernel.org
Link: http://lkml.kernel.org/r/20140606175316.GV13930@laptop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit:
commit 6f6343f53d
Author: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Date: Thu Apr 17 17:17:33 2014 +0900
kprobes/x86: Call exception handlers directly from do_int3/do_debug
appears to have inadvertently dropped a check that the int3 came
from kernel mode. Trying to dereference addr when addr is
user-controlled is completely bogus.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Link: http://lkml.kernel.org/r/c4e339882c121aa76254f2adde3fcbdf502faec2.1405099506.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
It's unnecessary to excessively spam the kernel log anytime the BTS buffer
cannot be allocated, so make this allocation __GFP_NOWARN.
The user probably will want to at least find some artifact that the
allocation has failed in the past, probably due to fragmentation because
of its large size, when it's not allocated at bootstrap. Thus, add a
WARN_ONCE() so something is left behind for them to understand why perf
commnads that require PEBS is not working properly.
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1406301600460.26302@chino.kir.corp.google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
With -cpu host, KVM reports LBR and extra_regs support, if the host has
support.
When the guest perf driver tries to access LBR or extra_regs MSR,
it #GPs all MSR accesses,since KVM doesn't handle LBR and extra_regs support.
So check the related MSRs access right once at initialization time to avoid
the error access at runtime.
For reproducing the issue, please build the kernel with CONFIG_KVM_INTEL = y
(for host kernel).
And CONFIG_PARAVIRT = n and CONFIG_KVM_GUEST = n (for guest kernel).
Start the guest with -cpu host.
Run perf record with --branch-any or --branch-filter in guest to trigger LBR
Run perf stat offcore events (E.g. LLC-loads/LLC-load-misses ...) in guest to
trigger offcore_rsp #GP
Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Maria Dimakopoulou <maria.n.dimakopoulou@gmail.com>
Cc: Mark Davies <junk@eslaf.co.uk>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Yan, Zheng <zheng.z.yan@intel.com>
Link: http://lkml.kernel.org/r/1405365957-20202-1-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch fixes the SNB-EP and IVT Cbox filter mapping
table. The table controls which filters are supported by
which events. There were several mistakes in those tables
causing some filters to be ignored, such as NID on
TOR_INSERTS.
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: zheng.z.yan@intel.com
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140630144624.GA2604@quad
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This was discussed back in February:
https://lkml.org/lkml/2014/2/18/956
But I never saw a patch come out of it.
On IvyBridge we share the SandyBridge cache event tables, but the
dTLB-load-miss event is not compatible. Patch it up after
the fact to the proper DTLB_LOAD_MISSES.DEMAND_LD_MISS_CAUSES_A_WALK
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1407141528200.17214@vincent-weaver-1.umelst.maine.edu
Signed-off-by: Ingo Molnar <mingo@kernel.org>
init_espfix_ap() is currently off by one level when informing hypervisor
that allocated pages will be used for ministacks' page tables.
The most immediate effect of this on a PV guest is that if
'stack_page = __get_free_page()' returns a non-zeroed-out page the hypervisor
will refuse to use it for a page table (which it shouldn't be anyway). This will
result in warnings by both Xen and Linux.
More importantly, a subsequent write to that page (again, by a PV guest) is
likely to result in fatal page fault.
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: http://lkml.kernel.org/r/1404926298-5565-1-git-send-email-boris.ostrovsky@oracle.com
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org>
which, apart from reducing code duplication also stops the arm64 stub
being rebuilt every time make is invoked - Ard Biesheuvel
* Fix the EFI fdt code to not report a boot error if UEFI is
unavailable since booting without UEFI parameters is a valid use case
for non-UEFI platforms - Catalin Marinas
* Include a .bss section in the EFI boot stub PE/COFF headers to fix a
memory corruption bug - Michael Brown
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Merge tag 'efi-urgent' into x86/urgent
* Remove a duplicate copy of linux_banner from the arm64 EFI stub
which, apart from reducing code duplication also stops the arm64 stub
being rebuilt every time make is invoked - Ard Biesheuvel
* Fix the EFI fdt code to not report a boot error if UEFI is
unavailable since booting without UEFI parameters is a valid use case
for non-UEFI platforms - Catalin Marinas
* Include a .bss section in the EFI boot stub PE/COFF headers to fix a
memory corruption bug - Michael Brown
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Pull x86 fixes from Peter Anvin:
"A couple of further build fixes for the VDSO code.
This is turning into a bit of a headache, and Andy has already come up
with a more ultimate cleanup, but most likely that is 3.17 material"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86-32, vdso: Fix vDSO build error due to missing align_vdso_addr()
x86-64, vdso: Fix vDSO build breakage due to empty .rela.dyn
Relying on static functions used just once to get inlined (and
subsequently have dead code paths eliminated) is wrong: Compilers are
free to decide whether they do this, regardless of optimization level.
With this not happening for vdso_addr() (observed with gcc 4.1.x), an
unresolved reference to align_vdso_addr() causes the build to fail.
[ hpa: vdso_addr() is never actually used on x86-32, as calculate_addr
in map_vdso() is always false. It ought to be possible to clean
this up further, but this fixes the immediate problem. ]
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/53B5863B02000078000204D5@mail.emea.novell.com
Acked-by: Andy Lutomirski <luto@amacapital.net>
Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Tested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Certain ld versions (observed with 2.20.0) put an empty .rela.dyn
section into shared object files, breaking the assumption on the number
of sections to be copied to the final output. Simply discard any empty
SHT_REL and SHT_RELA sections to address this.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/53B5861E02000078000204D1@mail.emea.novell.com
Acked-by: Andy Lutomirski <luto@amacapital.net>
Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Tested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Pull crypto fixes from Herbert Xu:
"This push fixes an error in sha512_ssse3 that leads to incorrect
output as well as a memory leak in caam_jr when the module is
unloaded"
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: caam - fix memleak in caam_jr module
crypto: sha512_ssse3 - fix byte count to bit count conversion
The PE/COFF headers currently describe only the initialised-data
portions of the image, and result in no space being allocated for the
uninitialised-data portions. Consequently, the EFI boot stub will end
up overwriting unexpected areas of memory, with unpredictable results.
Fix by including a .bss section in the PE/COFF headers (functionally
equivalent to the init_size field in the bzImage header).
Signed-off-by: Michael Brown <mbrown@fensystems.co.uk>
Cc: Thomas Bächler <thomas@archlinux.org>
Cc: Josh Boyer <jwboyer@fedoraproject.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
With commit b6b8a1451f that introduced
vmx_check_nested_events, checks for injectable interrupts happen
at different points in time for L1 and L2 that could potentially
cause a race. The regression occurs because KVM_REQ_EVENT is always
set when nested_run_pending is set even if there's no pending interrupt.
Consequently, there could be a small window when check_nested_events
returns without exiting to L1, but an interrupt comes through soon
after and it incorrectly, gets injected to L2 by inject_pending_event
Fix this by adding a call to check for nested events too when a check
for injectable interrupt returns true
Signed-off-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The 'sysret' fastpath does not correctly restore even all regular
registers, much less any segment registers or reflags values. That is
very much part of why it's faster than 'iret'.
Normally that isn't a problem, because the normal ptrace() interface
catches the process using the signal handler infrastructure, which
always returns with an iret.
However, some paths can get caught using ptrace_event() instead of the
signal path, and for those we need to make sure that we aren't going to
return to user space using 'sysret'. Otherwise the modifications that
may have been done to the register set by the tracer wouldn't
necessarily take effect.
Fix it by forcing IRET path by setting TIF_NOTIFY_RESUME from
arch_ptrace_stop_needed() which is invoked from ptrace_stop().
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Andy Lutomirski <luto@amacapital.net>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, any NMI is falsely handled by a NMI handler of NMI watchdog
if CondChgd bit in MSR_CORE_PERF_GLOBAL_STATUS MSR is set.
For example, we use external NMI to make system panic to get crash
dump, but in this case, the external NMI is falsely handled do to the
issue.
This commit deals with the issue simply by ignoring CondChgd bit.
Here is explanation in detail.
On x86 NMI watchdog uses performance monitoring feature to
periodically signal NMI each time performance counter gets overflowed.
intel_pmu_handle_irq() is called as a NMI_LOCAL handler from a NMI
handler of NMI watchdog, perf_event_nmi_handler(). It identifies an
owner of a given NMI by looking at overflow status bits in
MSR_CORE_PERF_GLOBAL_STATUS MSR. If some of the bits are set, then it
handles the given NMI as its own NMI.
The problem is that the intel_pmu_handle_irq() doesn't distinguish
CondChgd bit from other bits. Unlike the other status bits, CondChgd
bit doesn't represent overflow status for performance counters. Thus,
CondChgd bit cannot be thought of as a mark indicating a given NMI is
NMI watchdog's.
As a result, if CondChgd bit is set, any NMI is falsely handled by the
NMI handler of NMI watchdog. Also, if type of the falsely handled NMI
is either NMI_UNKNOWN, NMI_SERR or NMI_IO_CHECK, the corresponding
action is never performed until CondChgd bit is cleared.
I noticed this behavior on systems with Ivy Bridge processors: Intel
Xeon CPU E5-2630 v2 and Intel Xeon CPU E7-8890 v2. On both systems,
CondChgd bit in MSR_CORE_PERF_GLOBAL_STATUS MSR has already been set
in the beginning at boot. Then the CondChgd bit is immediately cleared
by next wrmsr to MSR_CORE_PERF_GLOBAL_CTRL MSR and appears to remain
0.
On the other hand, on older processors such as Nehalem, Xeon E7540,
CondChgd bit is not set in the beginning at boot.
I'm not sure about exact behavior of CondChgd bit, in particular when
this bit is set. Although I read Intel System Programmer's Manual to
figure out that, the descriptions I found are:
In 18.9.1:
"The MSR_PERF_GLOBAL_STATUS MSR also provides a ¡sticky bit¢ to
indicate changes to the state of performancmonitoring hardware"
In Table 35-2 IA-32 Architectural MSRs
63 CondChg: status bits of this register has changed.
These are different from the bahviour I see on the actual system as I
explained above.
At least, I think ignoring CondChgd bit should be enough for NMI
watchdog perspective.
Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/20140625.103503.409316067.d.hatayama@jp.fujitsu.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Mauro reported that his AMD X2 using the powernow-k8 cpufreq driver
locked up when doing cpu hotplug.
Because we called set_cyc2ns_scale() from the time_cpufreq_notifier()
unconditionally, it gets called multiple times for each freq change,
instead of only the once, when the tsc_khz value actually changes.
Because it gets called more than once, we run out of cyc2ns data slots
and stall, waiting for a free one, but because we're half way offline,
there's no consumers to free slots.
By placing the call inside the condition that actually changes tsc_khz
we avoid superfluous calls and avoid the problem.
Reported-by: Mauro <registosites@hotmail.com>
Tested-by: Mauro <registosites@hotmail.com>
Fixes: 20d1c86a57 ("sched/clock, x86: Rewrite cyc2ns() to avoid the need to disable IRQs")
Cc: <stable@vger.kernel.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Bin Gao <bin.gao@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Stefani Seibold <stefani@seibold.net>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The two more serious bugs ("KVM: SVM: Fix CPL export via SS.DPL" and
"KVM: s390: add sie.h uapi header file to Kbuild and remove header
dependency") were introduced in the 3.16 merge window.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Paolo Bonzini:
"A bunch of one-liners (except the s390 one).
The two more serious bugs ("KVM: SVM: Fix CPL export via SS.DPL" and
"KVM: s390: add sie.h uapi header file to Kbuild and remove header
dependency") were introduced in the 3.16 merge window"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: SVM: Fix CPL export via SS.DPL
KVM: s390: add sie.h uapi header file to Kbuild and remove header dependency
MIPS: KVM: Fix memory leak on VCPU
KVM: x86: preserve the high 32-bits of the PAT register
kvm: fix wrong address when writing Hyper-V tsc page
KVM: x86: Increase the number of fixed MTRR regs to 10
We import the CPL via SS.DPL since ae9fedc793. However, we fail to
export it this way so far. This caused spurious guest crashes, e.g. of
Linux when accessing the vmport from guest user space which triggered
register saving/restoring to/from host user space.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Pull x86 fixes from Peter Anvin:
"A pile of fixes related to the VDSO, EFI and 32-bit badsys handling.
It turns out that removing the section headers from the VDSO breaks
gdb, so this puts back most of them. A very simple typo broke
rt_sigreturn on some versions of glibc, with obviously disastrous
results. The rest is pretty much fixes for the corresponding fallout.
The EFI fixes fixes an arithmetic overflow on 32-bit systems and
quiets some build warnings.
Finally, when invoking an invalid system call number on x86-32, we
bypass a bunch of handling, which can make the audit code oops"
* 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
efi-pstore: Fix an overflow on 32-bit builds
x86/vdso: Error out in vdso2c if DT_RELA is present
x86/vdso: Move DISABLE_BRANCH_PROFILING into the vdso makefile
x86_32, signal: Fix vdso rt_sigreturn
x86_32, entry: Do syscall exit work on badsys (CVE-2014-4508)
x86/vdso: Create .build-id links for unstripped vdso files
x86/vdso: Remove some redundant in-memory section headers
x86/vdso: Improve the fake section headers
x86/vdso2c: Use better macros for ELF bitness
x86/vdso: Discard the __bug_table section
efi: Fix compiler warnings (unused, const, type)
Byte-to-bit-count computation is only partly converted to big-endian and is
mixing in CPU-endian values. Problem was noticed by sparce with warning:
CHECK arch/x86/crypto/sha512_ssse3_glue.c
arch/x86/crypto/sha512_ssse3_glue.c:144:19: warning: restricted __be64 degrades to integer
arch/x86/crypto/sha512_ssse3_glue.c:144:17: warning: incorrect type in assignment (different base types)
arch/x86/crypto/sha512_ssse3_glue.c:144:17: expected restricted __be64 <noident>
arch/x86/crypto/sha512_ssse3_glue.c:144:17: got unsigned long long
Cc: <stable@vger.kernel.org>
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>
Acked-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
vdso2c was checking for various types of relocations to detect when
the vdso had undefined symbols or was otherwise dependent on
relocation at load time. Undefined symbols in the vdso would fail if
accessed at runtime, and certain implementation errors (e.g. branch
profiling or incorrect symbol visibilities) could result in data
access through the GOT that requires relocations. This could be
as simple as:
extern char foo;
return foo;
Without some kind of visibility control, the compiler would assume
that foo could be interposed at load time and would generate a
relocation.
x86-64 and x32 (as opposed to i386) use explicit-addent (RELA) instead
of implicit-addent (REL) relocations for data access, and vdso2c
forgot to detect those.
Whether these bad relocations would actually fail at runtime depends
on what the linker sticks in the unrelocated references. Nonetheless,
these relocations have no business existing in the vDSO and should be
fixed rather than silently ignored.
This error could trigger on some configurations due to branch
profiling. The previous patch fixed that.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/74ef0c00b4d2a3b573e00a4113874e62f772e348.1403642755.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
DISABLE_BRANCH_PROFILING turns off branch profiling (i.e. a
redefinition of 'if'). Branch profiling depends on a bunch of
kernel-internal symbols and generates extra output sections, none of
which are useful or functional in the vDSO.
It's currently turned off for vclock_gettime.c, but vgetcpu.c also
triggers branch profiling, so just turn it off in the makefile.
This fixes the build on some configurations: the vdso could contain
undefined symbols, and the fake section table overflowed due to
ftrace's added sections.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/bf1ec29e03b2bbc081f6dcaefa64db1c3a83fb21.1403642755.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Sometimes it is preferred not to use the trigger_all_cpu_backtrace()
routine when one wants to avoid capturing a back trace for current. For
instance if one was previously captured recently.
This patch provides a new routine namely
trigger_allbutself_cpu_backtrace() which offers the flexibility to issue
an NMI to every cpu but current and capture a back trace accordingly.
Patch x86 and sparc to support new routine.
[dzickus@redhat.com: add stub in #else clause]
[dzickus@redhat.com: don't print message in single processor case, wrap with get/put_cpu based on Oleg's suggestion]
[sfr@canb.auug.org.au: undo C99ism]
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Mateusz Guzik <mguzik@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit:
commit 6f121e548f
Author: Andy Lutomirski <luto@amacapital.net>
Date: Mon May 5 12:19:34 2014 -0700
x86, vdso: Reimplement vdso.so preparation in build-time C
Contained this obvious typo:
- restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn);
+ restorer = current->mm->context.vdso +
+ selected_vdso32->sym___kernel_sigreturn;
Note the missing 'rt_' in the new code. Fix it.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/1eb40ad923acde2e18357ef2832867432e70ac42.1403361010.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The bad syscall nr paths are their own incomprehensible route
through the entry control flow. Rearrange them to work just like
syscalls that return -ENOSYS.
This fixes an OOPS in the audit code when fast-path auditing is
enabled and sysenter gets a bad syscall nr (CVE-2014-4508).
This has probably been broken since Linux 2.6.27:
af0575bba0 i386 syscall audit fast-path
Cc: stable@vger.kernel.org
Cc: Roland McGrath <roland@redhat.com>
Reported-by: Toralf Förster <toralf.foerster@gmx.de>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/e09c499eade6fc321266dd6b54da7beb28d6991c.1403558229.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Pull perf fixes from Ingo Molnar:
"This is larger than usual: the main reason are the ARM symbol lookup
speedups that came in late and were hard to resist.
There's also a kprobes fix and various tooling fixes, plus the minimal
re-enablement of the mmap2 support interface"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
x86/kprobes: Fix build errors and blacklist context_track_user
perf tests: Add test for closing dso objects on EMFILE error
perf tests: Add test for caching dso file descriptors
perf tests: Allow reuse of test_file function
perf tests: Spawn child for each test
perf tools: Add dso__data_* interface descriptons
perf tools: Allow to close dso fd in case of open failure
perf tools: Add file size check and factor dso__data_read_offset
perf tools: Cache dso data file descriptor
perf tools: Add global count of opened dso objects
perf tools: Add global list of opened dso objects
perf tools: Add data_fd into dso object
perf tools: Separate dso data related variables
perf tools: Cache register accesses for unwind processing
perf record: Fix to honor user freq/interval properly
perf timechart: Reflow documentation
perf probe: Improve error messages in --line option
perf probe: Improve an error message of perf probe --vars mode
perf probe: Show error code and description in verbose mode
perf probe: Improve error message for unknown member of data structure
...
With this change, doing 'make vdso_install' and telling gdb:
set debug-file-directory /lib/modules/KVER/vdso
will enable vdso debugging with symbols. This is useful for
testing, but kernel RPM builds will probably want to manually delete
these symlinks or otherwise do something sensible when they strip
the vdso/*.so files.
If ld does not support --build-id, then the symlinks will not be
created.
Note that kernel packagers that use vdso_install may need to adjust
their packaging scripts to accomdate this change. For example,
Fedora's scripts create build-id symlinks themselves in a different
location, so the spec should probably be updated to remove the
symlinks created by make vdso_install.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/a424b189ce3ced85fe1e82d032a20e765e0fe0d3.1403291930.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
- Fix for an ia64 regression introduced during the 3.11 cycle by a
commit that modified the hardware initialization ordering and made
device discovery fail on some systems.
- Fix for a build problem on systems where the cpufreq-cpu0 driver
is built-in and the cpu-thermal driver is modular from Arnd Bergmann.
- Fix for a recently introduced computational mistake in the
intel_pstate driver that leads to excessive rounding errors from
Doug Smythies.
- Fix for a failure code path in cpufreq_update_policy() that fails
to unlock the locks acquired previously from Aaron Plattner.
- Fix for the cpuidle mvebu driver to use shorter state names which
will prevent the sysfs interface from returning mangled strings.
From Gregory Clement.
- ACPI LPSS driver fix to make sure that the I2C controllers
included in BayTrail SoCs are not held in the reset state while
they are being probed from Mika Westerberg.
- New kernel command line arguments making it possible to build
kernel images with hibernation and kASLR included at the same
time and to select which of them will be used via the command
line (they are still functionally mutually exclusive, though).
From Kees Cook.
- ACPI battery driver quirk for Acer Aspire V5-573G that fails
to send battery status change notifications timely from
Alexander Mezin.
- Two ACPI core cleanups from Christoph Jaeger and Fabian Frederick.
/
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Merge tag 'pm+acpi-3.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI and power management fixes from Rafael Wysocki:
"These are fixes mostly (ia64 regression related to the ACPI
enumeration of devices, cpufreq regressions, fix for I2C controllers
included in Intel SoCs, mvebu cpuidle driver fix related to sysfs)
plus additional kernel command line arguments from Kees to make it
possible to build kernel images with hibernation and the kernel
address space randomization included simultaneously, a new ACPI
battery driver quirk for a system with a broken BIOS and a couple of
ACPI core cleanups.
Specifics:
- Fix for an ia64 regression introduced during the 3.11 cycle by a
commit that modified the hardware initialization ordering and made
device discovery fail on some systems.
- Fix for a build problem on systems where the cpufreq-cpu0 driver is
built-in and the cpu-thermal driver is modular from Arnd Bergmann.
- Fix for a recently introduced computational mistake in the
intel_pstate driver that leads to excessive rounding errors from
Doug Smythies.
- Fix for a failure code path in cpufreq_update_policy() that fails
to unlock the locks acquired previously from Aaron Plattner.
- Fix for the cpuidle mvebu driver to use shorter state names which
will prevent the sysfs interface from returning mangled strings.
From Gregory Clement.
- ACPI LPSS driver fix to make sure that the I2C controllers included
in BayTrail SoCs are not held in the reset state while they are
being probed from Mika Westerberg.
- New kernel command line arguments making it possible to build
kernel images with hibernation and kASLR included at the same time
and to select which of them will be used via the command line (they
are still functionally mutually exclusive, though). From Kees
Cook.
- ACPI battery driver quirk for Acer Aspire V5-573G that fails to
send battery status change notifications timely from Alexander
Mezin.
- Two ACPI core cleanups from Christoph Jaeger and Fabian Frederick"
* tag 'pm+acpi-3.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
cpuidle: mvebu: Fix the name of the states
cpufreq: unlock when failing cpufreq_update_policy()
intel_pstate: Correct rounding in busy calculation
ACPI: use kstrto*() instead of simple_strto*()
ACPI / processor replace __attribute__((packed)) by __packed
ACPI / battery: add quirk for Acer Aspire V5-573G
ACPI / battery: use callback for setting up quirks
ACPI / LPSS: Take I2C host controllers out of reset
x86, kaslr: boot-time selectable with hibernation
PM / hibernate: introduce "nohibernate" boot parameter
cpufreq: cpufreq-cpu0: fix CPU_THERMAL dependency
ACPI / ia64 / sba_iommu: Restore the working initialization ordering
.data doesn't need to be separate from .rodata: they're both readonly.
.altinstructions and .altinstr_replacement aren't needed by anything
except vdso2c; strip them from the final image.
While we're at it, rather than aligning the actual executable text,
just shove some unused-at-runtime data in between real data and
text.
My vdso image is still above 4k, but I'm disinclined to try to
trim it harder for 3.16. For future trimming, I suspect that these
sections could be moved to later in the file and dropped from
the in-memory image:
.gnu.version and .gnu.version_d (this may lose versions in gdb)
.eh_frame (should be harmless)
.eh_frame_hdr (I'm not really sure)
.hash (AFAIK nothing needs this section header)
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/2e96d0c49016ea6d026a614ae645e93edd325961.1403129369.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Fully stripping the vDSO has other unfortunate side effects:
- binutils is unable to find ELF notes without a SHT_NOTE section.
- Even elfutils has trouble: it can find ELF notes without a section
table at all, but if a section table is present, it won't look for
PT_NOTE.
- gdb wants section names to match between stripped DSOs and their
symbols; otherwise it will corrupt symbol addresses.
We're also breaking the rules: section 0 is supposed to be SHT_NULL.
Fix these problems by building a better fake section table. While
we're at it, we might as well let buggy Go versions keep working well
by giving the SHT_DYNSYM entry the correct size.
This is a bit unfortunate: it adds quite a bit of size to the vdso
image.
If/when binutils improves and the improved versions become widespread,
it would be worth considering dropping most of this.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/0e546a5eeaafdf1840e6ee654a55c1e727c26663.1403129369.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>