linux.git/arch/x86/kernel/cpu/mce, branch v5.11

x86/mce: Remove explicit/superfluous tracing

2021-01-12T20:10:59+00:00

There's some explicit tracing left in exc_machine_check_kernel(),
remove it, as it's already implied by irqentry_nmi_enter().

Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20210106144017.719310466@infradead.org

Merge tag 'core-entry-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-12-15T01:13:53+00:00

Pull core entry/exit updates from Thomas Gleixner:
 "A set of updates for entry/exit handling:

   - More generalization of entry/exit functionality

   - The consolidation work to reclaim TIF flags on x86 and also for
     non-x86 specific TIF flags which are solely relevant for syscall
     related work and have been moved into their own storage space. The
     x86 specific part had to be merged in to avoid a major conflict.

   - The TIF_NOTIFY_SIGNAL work which replaces the inefficient signal
     delivery mode of task work and results in an impressive performance
     improvement for io_uring. The non-x86 consolidation of this is
     going to come seperate via Jens.

   - The selective syscall redirection facility which provides a clean
     and efficient way to support the non-Linux syscalls of WINE by
     catching them at syscall entry and redirecting them to the user
     space emulation. This can be utilized for other purposes as well
     and has been designed carefully to avoid overhead for the regular
     fastpath. This includes the core changes and the x86 support code.

   - Simplification of the context tracking entry/exit handling for the
     users of the generic entry code which guarantee the proper ordering
     and protection.

   - Preparatory changes to make the generic entry code accomodate S390
     specific requirements which are mostly related to their syscall
     restart mechanism"

* tag 'core-entry-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
  entry: Add syscall_exit_to_user_mode_work()
  entry: Add exit_to_user_mode() wrapper
  entry_Add_enter_from_user_mode_wrapper
  entry: Rename exit_to_user_mode()
  entry: Rename enter_from_user_mode()
  docs: Document Syscall User Dispatch
  selftests: Add benchmark for syscall user dispatch
  selftests: Add kselftest for syscall user dispatch
  entry: Support Syscall User Dispatch on common syscall entry
  kernel: Implement selective syscall userspace redirection
  signal: Expose SYS_USER_DISPATCH si_code type
  x86: vdso: Expose sigreturn address on vdso to the kernel
  MAINTAINERS: Add entry for common entry code
  entry: Fix boot for !CONFIG_GENERIC_ENTRY
  x86: Support HAVE_CONTEXT_TRACKING_OFFSTACK
  context_tracking: Only define schedule_user() on !HAVE_CONTEXT_TRACKING_OFFSTACK archs
  sched: Detect call to schedule from critical entry code
  context_tracking: Don't implement exception_enter/exit() on CONFIG_HAVE_CONTEXT_TRACKING_OFFSTACK
  context_tracking: Introduce HAVE_CONTEXT_TRACKING_OFFSTACK
  x86: Reclaim unused x86 TI flags
  ...

Merge tag 'x86_cpu_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-12-14T21:21:33+00:00

Pull x86 cpuid updates from Borislav Petkov:
 "Only AMD-specific changes this time:

   - Save the AMD physical die ID into cpuinfo_x86.cpu_die_id and
     convert all code to use it (Yazen Ghannam)

   - Remove a dead and unused TSEG region remapping workaround on AMD
     (Arvind Sankar)"

* tag 'x86_cpu_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu/amd: Remove dead code for TSEG region remapping
  x86/topology: Set cpu_die_id only if DIE_TYPE found
  EDAC/mce_amd: Use struct cpuinfo_x86.cpu_die_id for AMD NodeId
  x86/CPU/AMD: Remove amd_get_nb_id()
  x86/CPU/AMD: Save AMD NodeId as cpu_die_id

x86/mce: Rename kill_it to kill_current_task

2020-12-01T17:58:50+00:00

Currently, if an MCE happens in user-mode or while the kernel is copying
data from user space, 'kill_it' is used to check if execution of the
interrupted task can be recovered or not; the flag name however is not
very meaningful, hence rename it to match its goal.

 [ bp: Massage commit message, rename the queue_task_work() arg too. ]

Signed-off-by: Gabriele Paoloni 
Signed-off-by: Borislav Petkov 
Link: https://lkml.kernel.org/r/20201127161819.3106432-6-gabriele.paoloni@intel.com

x86/mce: Remove redundant call to irq_work_queue()

2020-12-01T17:54:32+00:00

Currently, __mc_scan_banks() in do_machine_check() does the following
callchain:

  __mc_scan_banks()->mce_log()->irq_work_queue(&mce_irq_work).

Hence, the call to irq_work_queue() below after __mc_scan_banks()
seems redundant. Just remove it.

Signed-off-by: Gabriele Paoloni 
Signed-off-by: Borislav Petkov 
Reviewed-by: Tony Luck 
Link: https://lkml.kernel.org/r/20201127161819.3106432-5-gabriele.paoloni@intel.com

x86/mce: Panic for LMCE only if mca_cfg.tolerant < 3

2020-12-01T17:49:29+00:00

Right now for LMCE, if no_way_out is set, mce_panic() is called
regardless of mca_cfg.tolerant. This is not correct as, if
mca_cfg.tolerant = 3, the code should never panic.

Add that check.

 [ bp: use local ptr 'cfg'. ]

Signed-off-by: Gabriele Paoloni 
Signed-off-by: Borislav Petkov 
Reviewed-by: Tony Luck 
Link: https://lkml.kernel.org/r/20201127161819.3106432-4-gabriele.paoloni@intel.com

x86/mce: Move the mce_panic() call and 'kill_it' assignments to the right places

2020-12-01T17:45:56+00:00

Right now, for local MCEs the machine calls panic(), if needed, right
after lmce is set. For MCE broadcasting, mce_reign() takes care of
calling mce_panic().

Hence:
- improve readability by moving the conditional evaluation of
tolerant up to when kill_it is set first;
- move the mce_panic() call up into the statement where mce_end()
fails.

 [ bp: Massage, remove comment in the mce_end() failure case because it
   is superfluous; use local ptr 'cfg' in both tests. ]

Signed-off-by: Gabriele Paoloni 
Signed-off-by: Borislav Petkov 
Reviewed-by: Tony Luck 
Link: https://lkml.kernel.org/r/20201127161819.3106432-3-gabriele.paoloni@intel.com

Merge tag 'v5.10-rc6' into ras/core

2020-12-01T17:22:55+00:00

Merge the -rc6 tag to pick up dependent changes.

Signed-off-by: Borislav Petkov

x86/mce: Do not overwrite no_way_out if mce_end() fails

2020-11-27T16:38:36+00:00

Currently, if mce_end() fails, no_way_out - the variable denoting
whether the machine can recover from this MCE - is determined by whether
the worst severity that was found across the MCA banks associated with
the current CPU, is of panic severity.

However, at this point no_way_out could have been already set by
mca_start() after looking at all severities of all CPUs that entered the
MCE handler. If mce_end() fails, check first if no_way_out is already
set and, if so, stick to it, otherwise use the local worst value.

 [ bp: Massage. ]

Signed-off-by: Gabriele Paoloni 
Signed-off-by: Borislav Petkov 
Reviewed-by: Tony Luck 
Cc: 
Link: https://lkml.kernel.org/r/20201127161819.3106432-2-gabriele.paoloni@intel.com

x86/mce, cper: Pass x86 CPER through the MCA handling chain

2020-11-21T11:05:41+00:00

The kernel uses ACPI Boot Error Record Table (BERT) to report fatal
errors that occurred in a previous boot. The MCA errors in the BERT are
reported using the x86 Processor Error Common Platform Error Record
(CPER) format. Currently, the record prints out the raw MSR values and
AMD relies on the raw record to provide MCA information.

Extract the raw MSR values of MCA registers from the BERT and feed them
into mce_log() to decode them properly.

The implementation is SMCA-specific as the raw MCA register values are
given in the register offset order of the SMCA address space.

 [ bp: Massage. ]

[ Fix a build breakage in patch v1. ]
Reported-by: kernel test robot 
Signed-off-by: Smita Koralahalli 
Signed-off-by: Borislav Petkov 
Reviewed-by: Punit Agrawal 
Acked-by: Ard Biesheuvel 
Link: https://lkml.kernel.org/r/20201119182938.151155-1-Smita.KoralahalliChannabasappa@amd.com