linux.git/arch/x86/kernel/cpu/mcheck, branch v4.11

x86/mce: Make the MCE notifier a blocking one

2017-04-18T20:23:48+00:00

The NFIT MCE handler callback (for handling media errors on NVDIMMs)
takes a mutex to add the location of a memory error to a list. But since
the notifier call chain for machine checks (x86_mce_decoder_chain) is
atomic, we get a lockdep splat like:

  BUG: sleeping function called from invalid context at kernel/locking/mutex.c:620
  in_atomic(): 1, irqs_disabled(): 0, pid: 4, name: kworker/0:0
  [..]
  Call Trace:
   dump_stack
   ___might_sleep
   __might_sleep
   mutex_lock_nested
   ? __lock_acquire
   nfit_handle_mce
   notifier_call_chain
   atomic_notifier_call_chain
   ? atomic_notifier_call_chain
   mce_gen_pool_process

Convert the notifier to a blocking one which gets to run only in process
context.

Boris: remove the notifier call in atomic context in print_mce(). For
now, let's print the MCE on the atomic path so that we can make sure
they go out and get logged at least.

Fixes: 6839a6d96f4e ("nfit: do an ARS scrub on hitting a latent media error")
Reported-by: Ross Zwisler 
Signed-off-by: Vishal Verma 
Acked-by: Tony Luck 
Cc: Dan Williams 
Cc: linux-edac 
Cc: x86-ml 
Cc: 
Link: http://lkml.kernel.org/r/20170411224457.24777-1-vishal.l.verma@intel.com
Signed-off-by: Borislav Petkov 
Signed-off-by: Thomas Gleixner

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

2017-04-03T15:36:24+00:00

Pull RAS fix from Thomas Gleixner:
 "Prevent dmesg from being spammed when MCE logging is active"

* 'ras-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mce: Don't print MCEs when mcelog is active

x86/mce/AMD: Give a name to MCA bank 3 when accessed with legacy MSRs

2017-03-31T08:09:44+00:00

MCA bank 3 is reserved on systems pre-Fam17h, so it didn't have a name.
However, MCA bank 3 is defined on Fam17h systems and can be accessed
using legacy MSRs. Without a name we get a stack trace on Fam17h systems
when trying to register sysfs files for bank 3 on kernels that don't
recognize Scalable MCA.

Call MCA bank 3 "decode_unit" since this is what it represents on
Fam17h. This will allow kernels without SMCA support to see this bank on
Fam17h+ and prevent the stack trace. This will not affect older systems
since this bank is reserved on them, i.e. it'll be ignored.

Tested on AMD Fam15h and Fam17h systems.

  WARNING: CPU: 26 PID: 1 at lib/kobject.c:210 kobject_add_internal
  kobject: (ffff88085bb256c0): attempted to be registered with empty name!
  ...
  Call Trace:
   kobject_add_internal
   kobject_add
   kobject_create_and_add
   threshold_create_device
   threshold_init_device

Signed-off-by: Yazen Ghannam 
Signed-off-by: Borislav Petkov 
Link: http://lkml.kernel.org/r/1490102285-3659-1-git-send-email-Yazen.Ghannam@amd.com
Signed-off-by: Thomas Gleixner

x86/mce: Don't print MCEs when mcelog is active

2017-03-28T06:53:52+00:00

Since:

  cd9c57cad3fe ("x86/MCE: Dump MCE to dmesg if no consumers")

all MCEs are printed even when mcelog is running. Fix the regression to
not print to dmesg when mcelog is running as it is a consumer too.

Signed-off-by: Andi Kleen 
[ Massage commit message. ]
Signed-off-by: Borislav Petkov 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Cc: linux-edac 
Cc: stable@vger.kernel.org # 4.10..
Fixes: cd9c57cad3fe ("x86/MCE: Dump MCE to dmesg if no consumers")
Link: http://lkml.kernel.org/r/20170327093304.10683-2-bp@alien8.de
Signed-off-by: Ingo Molnar 

Signed-off-by: Ingo Molnar

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

2017-02-28T19:46:00+00:00

Pull x86 fixes from Ingo Molnar:
 "Two documentation updates, plus a debugging annotation fix"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/crash: Update the stale comment in reserve_crashkernel()
  x86/irq, trace: Add __irq_entry annotation to x86's platform IRQ handlers
  Documentation, x86, resctrl: Recommend locking for resctrlfs

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

2017-02-20T20:47:44+00:00

Pull RAS updates from Ingo Molnar:
 "The main changes in this cycle were:

  - Assign notifier chain priorities for all RAS related handlers to
    make the ordering explicit (Borislav Petkov)

  - Improve the AMD MCA banks sysfs output (Yazen Ghannam)

  - Various cleanups and restructuring of the x86 RAS code (Borislav
    Petkov)"

* 'ras-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/ras, EDAC, acpi: Assign MCE notifier handlers a priority
  x86/ras: Get rid of mce_process_work()
  EDAC/mce/amd: Dump TSC value
  EDAC/mce/amd: Unexport amd_decode_mce()
  x86/ras/amd/inj: Change dependency
  x86/ras: Flip the TSC-adding logic
  x86/ras/amd: Make sysfs names of banks more user-friendly
  x86/ras/therm_throt: Do not log a fake MCE for thermal events
  x86/ras/inject: Make it depend on X86_LOCAL_APIC=y

Merge branches 'x86/cache', 'x86/debug' and 'x86/irq' into x86/urgent

2017-02-20T13:16:58+00:00

Pick up simple singular commits from their topic branches.

Signed-off-by: Ingo Molnar

x86/mce: Make timer handling more robust

2017-01-31T20:47:58+00:00

Erik reported that on a preproduction hardware a CMCI storm triggers the
BUG_ON in add_timer_on(). The reason is that the per CPU MCE timer is
started by the CMCI logic before the MCE CPU hotplug callback starts the
timer with add_timer_on(). So the timer is already queued which triggers
the BUG.

Using add_timer_on() is pretty pointless in this code because the timer is
strictlty per CPU, initialized as pinned and all operations which arm the
timer happen on the CPU to which the timer belongs.

Simplify the whole machinery by using mod_timer() instead of add_timer_on()
which avoids the problem because mod_timer() can handle already queued
timers. Use __start_timer() everywhere so the earliest armed expiry time is
preserved.

Reported-by: Erik Veijola 
Tested-by: Borislav Petkov 
Signed-off-by: Thomas Gleixner 
Reviewed-by: Borislav Petkov 
Cc: Tony Luck 
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1701310936080.3457@nanos
Signed-off-by: Thomas Gleixner

x86/ras, EDAC, acpi: Assign MCE notifier handlers a priority

2017-01-24T08:14:57+00:00

Assign all notifiers on the MCE decode chain a priority so that they get
called in the correct order.

Suggested-by: Thomas Gleixner 
Signed-off-by: Borislav Petkov 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Tony Luck 
Cc: Yazen Ghannam 
Cc: linux-edac 
Link: http://lkml.kernel.org/r/20170123183514.13356-10-bp@alien8.de
Signed-off-by: Ingo Molnar

x86/ras: Get rid of mce_process_work()

2017-01-24T08:14:56+00:00

Make mce_gen_pool_process() the workqueue function directly and save us
an indirection.

Signed-off-by: Borislav Petkov 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Cc: Yazen Ghannam 
Cc: linux-edac 
Link: http://lkml.kernel.org/r/20170123183514.13356-9-bp@alien8.de
Signed-off-by: Ingo Molnar