linux-stable.git/arch/x86/kernel/cpu, branch linux-4.3.y

x86/mce: Ensure offline CPUs don't participate in rendezvous process

2016-01-31T19:25:43+00:00

commit d90167a941f62860f35eb960e1012aa2d30e7e94 upstream.

Intel's MCA implementation broadcasts MCEs to all CPUs on the
node. This poses a problem for offlined CPUs which cannot
participate in the rendezvous process:

  Kernel panic - not syncing: Timeout: Not all CPUs entered broadcast exception handler
  Kernel Offset: disabled
  Rebooting in 100 seconds..

More specifically, Linux does a soft offline of a CPU when
writing a 0 to /sys/devices/system/cpu/cpuX/online, which
doesn't prevent the #MC exception from being broadcasted to that
CPU.

Ensure that offline CPUs don't participate in the MCE rendezvous
and clear the RIP valid status bit so that a second MCE won't
cause a shutdown.

Without the patch, mce_start() will increment mce_callin and
wait for all CPUs. Offlined CPUs should avoid participating in
the rendezvous process altogether.

Signed-off-by: Ashok Raj 
[ Massage commit message. ]
Signed-off-by: Borislav Petkov 
Reviewed-by: Tony Luck 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-edac 
Link: http://lkml.kernel.org/r/1449742346-21470-2-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

x86/cpu: Fix SMAP check in PVOPS environments

2015-12-09T19:34:18+00:00

commit 581b7f158fe0383b492acd1ce3fb4e99d4e57808 upstream.

There appears to be no formal statement of what pv_irq_ops.save_fl() is
supposed to return precisely.  Native returns the full flags, while lguest and
Xen only return the Interrupt Flag, and both have comments by the
implementations stating that only the Interrupt Flag is looked at.  This may
have been true when initially implemented, but no longer is.

To make matters worse, the Xen PVOP leaves the upper bits undefined, making
the BUG_ON() undefined behaviour.  Experimentally, this now trips for 32bit PV
guests on Broadwell hardware.  The BUG_ON() is consistent for an individual
build, but not consistent for all builds.  It has also been a sitting timebomb
since SMAP support was introduced.

Use native_save_fl() instead, which will obtain an accurate view of the AC
flag.

Signed-off-by: Andrew Cooper 
Reviewed-by: David Vrabel 
Tested-by: Rusty Russell 
Cc: Rusty Russell 
Cc: Konrad Rzeszutek Wilk 
Cc: Boris Ostrovsky 
Cc: 
Cc: Xen-devel 
Link: http://lkml.kernel.org/r/1433323874-6927-1-git-send-email-andrew.cooper3@citrix.com
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2015-10-03T14:53:05+00:00

Pull x86 fixes from Ingo Molnar:
 "Fixes all around the map: W+X kernel mapping fix, WCHAN fixes, two
  build failure fixes for corner case configs, x32 header fix and a
  speling fix"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/headers/uapi: Fix __BITS_PER_LONG value for x32 builds
  x86/mm: Set NX on gap between __ex_table and rodata
  x86/kexec: Fix kexec crash in syscall kexec_file_load()
  x86/process: Unify 32bit and 64bit implementations of get_wchan()
  x86/process: Add proper bound checks in 64bit get_wchan()
  x86, efi, kasan: Fix build failure on !KASAN && KMEMCHECK=y kernels
  x86/hyperv: Fix the build in the !CONFIG_KEXEC_CORE case
  x86/cpufeatures: Correct spelling of the HWP_NOTIFY flag

x86/hyperv: Fix the build in the !CONFIG_KEXEC_CORE case

2015-09-30T05:44:15+00:00

Recent changes in the Hyper-V driver:

  b4370df2b1f5 ("Drivers: hv: vmbus: add special crash handler")

broke the build when CONFIG_KEXEC_CORE is not set:

  arch/x86/built-in.o: In function `hv_machine_crash_shutdown':
  arch/x86/kernel/cpu/mshyperv.c:112: undefined reference to `native_machine_crash_shutdown'

Decorate all kexec related code with #ifdef CONFIG_KEXEC_CORE.

Reported-by: Jim Davis 
Reported-by: Stephen Hemminger 
Signed-off-by: Vitaly Kuznetsov 
Signed-off-by: Thomas Gleixner 
Cc: devel@linuxdriverproject.org
Cc: K. Y. Srinivasan 
Cc: Haiyang Zhang 
Cc: Greg Kroah-Hartman 
Cc: Peter Zijlstra 
Cc: Linus Torvalds 
Link: http://lkml.kernel.org/r/1443002577-25370-1-git-send-email-vkuznets@redhat.com
Signed-off-by: Ingo Molnar

perf/x86: Change test_aperfmperf() and test_intel() to static

2015-09-25T07:42:40+00:00

Fixes the following sparse warnings:

 arch/x86/kernel/cpu/perf_event_msr.c:13:6: warning: symbol
 'test_aperfmperf' was not declared. Should it be static?

 arch/x86/kernel/cpu/perf_event_msr.c:18:6: warning: symbol
 'test_intel' was not declared. Should it be static?

Signed-off-by: Geliang Tang 
Cc: Arnaldo Carvalho de Melo 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/4588e8ab09638458f2451af572827108be3b4a36.1443123796.git.geliangtang@163.com
Signed-off-by: Ingo Molnar

x86/cpufeatures: Correct spelling of the HWP_NOTIFY flag

2015-09-23T07:57:24+00:00

Because noitification just isn't right.

Signed-off-by: Kristen Carlson Accardi 
Acked-by: Rafael J. Wysocki 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Cc: rjw@rjwysocki.net
Link: http://lkml.kernel.org/r/1442944296-11737-1-git-send-email-kristen@linux.intel.com
Signed-off-by: Ingo Molnar

perf/x86/intel: Fix Skylake FRONTEND MSR extrareg mask

2015-09-18T07:20:23+00:00

Stephane pointed out that the extrareg mask was one bit too short.
The bubble width field was truncated by one bit. Fix that here.
Also add some extra comments on the reserved bits inside the event
select code.

Reported-by: Stephane Eranian 
Signed-off-by: Andi Kleen 
Signed-off-by: Peter Zijlstra (Intel) 
Acked-by: Thomas Gleixner 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1441835640-21347-3-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar

perf/x86/intel/pebs: Add PEBS frontend profiling for Skylake

2015-09-18T07:20:22+00:00

Skylake has a new FRONTEND_LATENCY PEBS event to accurately profile
frontend problems (like ITLB or decoding issues).

The new event is configured through a separate MSR, which selects
a range of sub events.

Define the extra MSR as a extra reg and export support for it
through sysfs.  To avoid duplicating the existing
tables use a new function to add new entries to existing tables.

Signed-off-by: Andi Kleen 
Signed-off-by: Peter Zijlstra (Intel) 
Acked-by: Thomas Gleixner 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1435707205-6676-4-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar

perf/x86/intel: Make the CYCLE_ACTIVITY.* constraint on Broadwell more specific

2015-09-18T07:20:21+00:00

The counter constraint for CYCLE_ACTIVITY.* on Broadwell covered
all CYCLE_ACTIVITY.* sub events, and forced them on counter 2.
But actually only one sub event (umask 8) needs to be on counter 2,
all others do not have any constraint.

Only force that subevent. This fixes groups with multiple
CYCLE_ACTIVITY.* events, for example:

	% perf stat -x, -e '{cpu/event=0xa3,umask=0x6,cmask=6/,\
	cpu/event=0xa2,umask=0x8/,\
	cpu/event=0xa3,umask=0x4,cmask=4/,cpu/event=0xb1,umask=0x1,cmask=1/}' true
	122150,,cpu/event=0xa3,umask=0x6,cmask=6/,846486,100.00
	16483,,cpu/event=0xa2,umask=0x8/,846486,100.00
	252280,,cpu/event=0xa3,umask=0x4,cmask=4/,846486,100.00
	233604,,cpu/event=0xb1,umask=0x1,cmask=1/,846486,100.00
	%

Without this patch the third result would be 

Signed-off-by: Andi Kleen 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1442267222-16464-1-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar

Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2015-09-17T18:01:34+00:00

Pull x86 fixes from Ingo Molnar:
 - misc fixes all around the map
 - block non-root vm86(old) if mmap_min_addr != 0
 - two small debuggability improvements
 - removal of obsolete paravirt op

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/platform: Fix Geode LX timekeeping in the generic x86 build
  x86/apic: Serialize LVTT and TSC_DEADLINE writes
  x86/ioapic: Force affinity setting in setup_ioapic_dest()
  x86/paravirt: Remove the unused pv_time_ops::get_tsc_khz method
  x86/ldt: Fix small LDT allocation for Xen
  x86/vm86: Fix the misleading CONFIG_VM86 Kconfig help text
  x86/cpu: Print family/model/stepping in hex
  x86/vm86: Block non-root vm86(old) if mmap_min_addr != 0
  x86/alternatives: Make optimize_nops() interrupt safe and synced
  x86/mm/srat: Print non-volatile flag in SRAT
  x86/cpufeatures: Enable cpuid for Intel SHA extensions