Commit Graph

559 Commits

Author SHA1 Message Date
Linus Torvalds
5778077d03 Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 asm changes from Ingo Molnar:
 "The biggest changes in this cycle were:

   - Revamp, simplify (and in some cases fix) Time Stamp Counter (TSC)
     primitives.  (Andy Lutomirski)

   - Add new, comprehensible entry and exit handlers written in C.
     (Andy Lutomirski)

   - vm86 mode cleanups and fixes.  (Brian Gerst)

   - 32-bit compat code cleanups.  (Brian Gerst)

  The amount of simplification in low level assembly code is already
  palpable:

     arch/x86/entry/entry_32.S                          | 130 +----
     arch/x86/entry/entry_64.S                          | 197 ++-----

  but more simplifications are planned.

  There's also the usual laudry mix of low level changes - see the
  changelog for details"

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (83 commits)
  x86/asm: Drop repeated macro of X86_EFLAGS_AC definition
  x86/asm/msr: Make wrmsrl() a function
  x86/asm/delay: Introduce an MWAITX-based delay with a configurable timer
  x86/asm: Add MONITORX/MWAITX instruction support
  x86/traps: Weaken context tracking entry assertions
  x86/asm/tsc: Add rdtscll() merge helper
  selftests/x86: Add syscall_nt selftest
  selftests/x86: Disable sigreturn_64
  x86/vdso: Emit a GNU hash
  x86/entry: Remove do_notify_resume(), syscall_trace_leave(), and their TIF masks
  x86/entry/32: Migrate to C exit path
  x86/entry/32: Remove 32-bit syscall audit optimizations
  x86/vm86: Rename vm86->v86flags and v86mask
  x86/vm86: Rename vm86->vm86_info to user_vm86
  x86/vm86: Clean up vm86.h includes
  x86/vm86: Move the vm86 IRQ definitions to vm86.h
  x86/vm86: Use the normal pt_regs area for vm86
  x86/vm86: Eliminate 'struct kernel_vm86_struct'
  x86/vm86: Move fields from 'struct kernel_vm86_struct' to 'struct vm86'
  x86/vm86: Move vm86 fields out of 'thread_struct'
  ...
2015-09-01 08:40:25 -07:00
Linus Torvalds
3959df1dfb Merge branch 'ras-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RAS updates from Ingo Molnar:
 "MCE handling updates, but also some generic drivers/edac/ changes to
  better organize the Kconfig space"

* 'ras-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/ras: Move AMD MCE injector to arch/x86/ras/
  x86/mce: Add a wrapper around mce_log() for injection
  x86/mce: Rename rcu_dereference_check_mce() to mce_log_get_idx_check()
  RAS: Add a menuconfig option with descriptive text
  x86/mce: Reenable CMCI banks when swiching back to interrupt mode
  x86/mce: Clear Local MCE opt-in before kexec
  x86/mce: Remove unused function declarations
  x86/mce: Kill drain_mcelog_buffer()
  x86/mce: Avoid potential deadlock due to printk() in MCE context
  x86/mce: Remove the MCE ring for Action Optional errors
  x86/mce: Don't use percpu workqueues
  x86/mce: Provide a lockless memory pool to save error records
  x86/mce: Reuse one of the u16 padding fields in 'struct mce'
2015-08-31 20:20:30 -07:00
Borislav Petkov
a79da38494 x86/mce: Add a wrapper around mce_log() for injection
Will be used by an injector module in a following patch.

Additionally, add a missing module export reported by 0-DAY
kernel test.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/1439396985-12812-13-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-13 10:12:53 +02:00
Borislav Petkov
9a7783d021 x86/mce: Rename rcu_dereference_check_mce() to mce_log_get_idx_check()
The "rcu_" prefix misleads for it being a proper RCU interface
which is not. It basically checks whether we're preemptible or
holding the chrdev_read mutex.

Rename it accordingly.

Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/1439396985-12812-12-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-13 10:12:53 +02:00
Xie XiuQi
1b48465500 x86/mce: Reenable CMCI banks when swiching back to interrupt mode
Zhang Liguang reported the following issue:

1) System detects a CMCI storm on the current CPU.

2) Kernel disables the CMCI interrupt on banks owned by the
   current CPU and switches to poll mode

3) After the CMCI storm subsides, kernel switches back to
   interrupt mode

4) We expect the system to reenable the CMCI interrupt on banks
   owned by the current CPU

   mce_intel_adjust_timer
   |-> cmci_reenable
       |-> cmci_discover     # owned banks are ignored here

  static void cmci_discover(int banks)
	...
	for (i = 0; i < banks; i++) {
		...
		if (test_bit(i, owned))	# ownd banks is ignore here
			continue;

So convert cmci_storm_disable_banks() to
cmci_toggle_interrupt_mode() which controls whether to enable or
disable CMCI interrupts with its argument.

NB: We cannot clear the owned bit because the banks won't be
polled, otherwise. See:

  27f6c573e0 ("x86, CMCI: Add proper detection of end of CMCI storms")

for more info.

Reported-by: Zhang Liguang <zhangliguang@huawei.com>
Signed-off-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org> # v3.15+
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: huawei.libin@huawei.com
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: rui.xiang@huawei.com
Link: http://lkml.kernel.org/r/1439396985-12812-10-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-13 10:12:52 +02:00
Ashok Raj
8838eb6c0b x86/mce: Clear Local MCE opt-in before kexec
kexec could boot a kernel that could be legacy with no knowledge
of LMCE. Hence we should make sure we clear LMCE optin before
kexec reboot.

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1439396985-12812-9-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-13 10:12:52 +02:00
Borislav Petkov
eef4dfa0cb x86/mce: Kill drain_mcelog_buffer()
This used to flush out MCEs logged during early boot and which
were in the MCA registers from a previous system run. No need
for that now, since we've moved to a genpool.

Suggested-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1439396985-12812-7-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-13 10:12:52 +02:00
Chen, Gong
f29a7aff4b x86/mce: Avoid potential deadlock due to printk() in MCE context
Printing in MCE context is a no-no, currently, as printk() is
not NMI-safe. If some of the notifiers on the MCE chain call do
so, we may deadlock. In order to avoid that, delay printk() to
process context where it is safe.

Reported-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Chen, Gong <gong.chen@linux.intel.com>
[ Fold in subsequent patch from Boris for early boot logging. ]
Signed-off-by: Tony Luck <tony.luck@intel.com>
[ Kick irq_work in mce_log() directly. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1439396985-12812-6-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-13 10:12:51 +02:00
Chen, Gong
fd4cf79fcc x86/mce: Remove the MCE ring for Action Optional errors
Use unified genpool to save Action Optional error events and put
Action Optional error handling in the same notification chain as
MCE error decoding.

Signed-off-by: Chen, Gong <gong.chen@linux.intel.com>
[ Fold in subsequent patch from Boris for early boot logging. ]
Signed-off-by: Tony Luck <tony.luck@intel.com>
[ Correct a lot. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1439396985-12812-5-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-13 10:12:51 +02:00
Chen, Gong
061120aed7 x86/mce: Don't use percpu workqueues
An MCE is a rare event. Therefore, there's no need to have
per-CPU instances of both normal and IRQ workqueues. Make them
both global.

Signed-off-by: Chen, Gong <gong.chen@linux.intel.com>
[ Fold in subsequent patch from Rui/Boris/Tony for early boot logging. ]
Signed-off-by: Tony Luck <tony.luck@intel.com>
[ Massage commit message. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1439396985-12812-4-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-13 10:12:51 +02:00
Chen, Gong
648ed94038 x86/mce: Provide a lockless memory pool to save error records
printk() is not safe to use in MCE context. Add a lockless
memory allocator pool to save error records in MCE context.
Those records will be issued later, in a printk-safe context.
The idea is inspired by the APEI/GHES driver.

We're very conservative and allocate only two pages for it but
since we're going to use those pages throughout the system's
lifetime, we allocate them statically to avoid early boot time
allocation woes.

Signed-off-by: Chen, Gong <gong.chen@linux.intel.com>
[ Rewrite. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/1439396985-12812-3-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-13 10:12:50 +02:00
Paul E. McKenney
f78f5b90c4 rcu: Rename rcu_lockdep_assert() to RCU_LOCKDEP_WARN()
This commit renames rcu_lockdep_assert() to RCU_LOCKDEP_WARN() for
consistency with the WARN() series of macros.  This also requires
inverting the sense of the conditional, which this commit also does.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
2015-07-22 15:27:32 -07:00
Andy Lutomirski
8c84014f3b x86/entry: Remove exception_enter() from most trap handlers
On 64-bit kernels, we don't need it any more: we handle context
tracking directly on entry from user mode and exit to user mode.

On 32-bit kernels, we don't support context tracking at all, so
these callbacks had no effect.

Note: this doesn't change do_page_fault().  Before we do that,
we need to make sure that there is no code that can page fault
from kernel mode with CONTEXT_USER.  The 32-bit fast system call
stack argument code is the only offender I'm aware of right now.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: paulmck@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/ae22f4dfebd799c916574089964592be218151f9.1435952415.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-07 10:59:09 +02:00
Andy Lutomirski
4ea1636b04 x86/asm/tsc: Rename native_read_tsc() to rdtsc()
Now that there is no paravirt TSC, the "native" is
inappropriate. The function does RDTSC, so give it the obvious
name: rdtsc().

Suggested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm ML <kvm@vger.kernel.org>
Link: http://lkml.kernel.org/r/fd43e16281991f096c1e4d21574d9e1402c62d39.1434501121.git.luto@kernel.org
[ Ported it to v4.2-rc1. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-06 15:23:28 +02:00
Andy Lutomirski
87be28aaf1 x86/asm/tsc: Replace rdtscll() with native_read_tsc()
Now that the ->read_tsc() paravirt hook is gone, rdtscll() is
just a wrapper around native_read_tsc(). Unwrap it.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm ML <kvm@vger.kernel.org>
Link: http://lkml.kernel.org/r/d2449ae62c1b1fb90195bcfb19ef4a35883a04dc.1434501121.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-06 15:23:26 +02:00
Linus Torvalds
d70b3ef54c Merge branch 'x86-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 core updates from Ingo Molnar:
 "There were so many changes in the x86/asm, x86/apic and x86/mm topics
  in this cycle that the topical separation of -tip broke down somewhat -
  so the result is a more traditional architecture pull request,
  collected into the 'x86/core' topic.

  The topics were still maintained separately as far as possible, so
  bisectability and conceptual separation should still be pretty good -
  but there were a handful of merge points to avoid excessive
  dependencies (and conflicts) that would have been poorly tested in the
  end.

  The next cycle will hopefully be much more quiet (or at least will
  have fewer dependencies).

  The main changes in this cycle were:

   * x86/apic changes, with related IRQ core changes: (Jiang Liu, Thomas
     Gleixner)

     - This is the second and most intrusive part of changes to the x86
       interrupt handling - full conversion to hierarchical interrupt
       domains:

          [IOAPIC domain]   -----
                                 |
          [MSI domain]      --------[Remapping domain] ----- [ Vector domain ]
                                 |   (optional)          |
          [HPET MSI domain] -----                        |
                                                         |
          [DMAR domain]     -----------------------------
                                                         |
          [Legacy domain]   -----------------------------

       This now reflects the actual hardware and allowed us to distangle
       the domain specific code from the underlying parent domain, which
       can be optional in the case of interrupt remapping.  It's a clear
       separation of functionality and removes quite some duct tape
       constructs which plugged the remap code between ioapic/msi/hpet
       and the vector management.

     - Intel IOMMU IRQ remapping enhancements, to allow direct interrupt
       injection into guests (Feng Wu)

   * x86/asm changes:

     - Tons of cleanups and small speedups, micro-optimizations.  This
       is in preparation to move a good chunk of the low level entry
       code from assembly to C code (Denys Vlasenko, Andy Lutomirski,
       Brian Gerst)

     - Moved all system entry related code to a new home under
       arch/x86/entry/ (Ingo Molnar)

     - Removal of the fragile and ugly CFI dwarf debuginfo annotations.
       Conversion to C will reintroduce many of them - but meanwhile
       they are only getting in the way, and the upstream kernel does
       not rely on them (Ingo Molnar)

     - NOP handling refinements. (Borislav Petkov)

   * x86/mm changes:

     - Big PAT and MTRR rework: making the code more robust and
       preparing to phase out exposing direct MTRR interfaces to drivers -
       in favor of using PAT driven interfaces (Toshi Kani, Luis R
       Rodriguez, Borislav Petkov)

     - New ioremap_wt()/set_memory_wt() interfaces to support
       Write-Through cached memory mappings.  This is especially
       important for good performance on NVDIMM hardware (Toshi Kani)

   * x86/ras changes:

     - Add support for deferred errors on AMD (Aravind Gopalakrishnan)

       This is an important RAS feature which adds hardware support for
       poisoned data.  That means roughly that the hardware marks data
       which it has detected as corrupted but wasn't able to correct, as
       poisoned data and raises an APIC interrupt to signal that in the
       form of a deferred error.  It is the OS's responsibility then to
       take proper recovery action and thus prolonge system lifetime as
       far as possible.

     - Add support for Intel "Local MCE"s: upcoming CPUs will support
       CPU-local MCE interrupts, as opposed to the traditional system-
       wide broadcasted MCE interrupts (Ashok Raj)

     - Misc cleanups (Borislav Petkov)

   * x86/platform changes:

     - Intel Atom SoC updates

  ... and lots of other cleanups, fixlets and other changes - see the
  shortlog and the Git log for details"

* 'x86-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (222 commits)
  x86/hpet: Use proper hpet device number for MSI allocation
  x86/hpet: Check for irq==0 when allocating hpet MSI interrupts
  x86/mm/pat, drivers/infiniband/ipath: Use arch_phys_wc_add() and require PAT disabled
  x86/mm/pat, drivers/media/ivtv: Use arch_phys_wc_add() and require PAT disabled
  x86/platform/intel/baytrail: Add comments about why we disabled HPET on Baytrail
  genirq: Prevent crash in irq_move_irq()
  genirq: Enhance irq_data_to_desc() to support hierarchy irqdomain
  iommu, x86: Properly handle posted interrupts for IOMMU hotplug
  iommu, x86: Provide irq_remapping_cap() interface
  iommu, x86: Setup Posted-Interrupts capability for Intel iommu
  iommu, x86: Add cap_pi_support() to detect VT-d PI capability
  iommu, x86: Avoid migrating VT-d posted interrupts
  iommu, x86: Save the mode (posted or remapped) of an IRTE
  iommu, x86: Implement irq_set_vcpu_affinity for intel_ir_chip
  iommu: dmar: Provide helper to copy shared irte fields
  iommu: dmar: Extend struct irte for VT-d Posted-Interrupts
  iommu: Add new member capability to struct irq_remap_ops
  x86/asm/entry/64: Disentangle error_entry/exit gsbase/ebx/usermode code
  x86/asm/entry/32: Shorten __audit_syscall_entry() args preparation
  x86/asm/entry/32: Explain reloading of registers after __audit_syscall_entry()
  ...
2015-06-22 17:59:09 -07:00
Ingo Molnar
c2f9b0af8b Merge branch 'x86/ras' into x86/core, to fix conflicts
Conflicts:
	arch/x86/include/asm/irq_vectors.h

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-06-07 15:35:27 +02:00
Ashok Raj
243d657eaf x86/mce: Handle Local MCE events
Add the necessary changes to do_machine_check() to be able to
process MCEs signaled as local MCEs. Typically, only recoverable
errors (SRAR type) will be Signaled as LMCE. The architecture
does not restrict to only those errors, however.

When errors are signaled as LMCE, there is no need for the MCE
handler to perform rendezvous with other logical processors
unlike earlier processors that would broadcast machine check
errors.

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1433436928-31903-17-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-06-07 15:33:15 +02:00
Ashok Raj
88d538672e x86/mce: Add infrastructure to support Local MCE
Initialize and prepare for handling LMCEs. Add a boot-time
option to disable LMCEs.

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
[ Simplify stuff, align statements for better readability, reflow comments; kill
  unused lmce_clear(); save us an MSR write if LMCE is already enabled. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1433436928-31903-16-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-06-07 15:33:14 +02:00
Ingo Molnar
085c789783 Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull RCU changes from Paul E. McKenney:

  - Initialization/Kconfig updates: hide most Kconfig options from unsuspecting users.
    There's now a single high level configuration option:

      *
      * RCU Subsystem
      *
      Make expert-level adjustments to RCU configuration (RCU_EXPERT) [N/y/?] (NEW)

    Which if answered in the negative, leaves us with a single interactive
    configuration option:

      Offload RCU callback processing from boot-selected CPUs (RCU_NOCB_CPU) [N/y/?] (NEW)

    All the rest of the RCU options are configured automatically.

  - Remove all uses of RCU-protected array indexes: replace the
    rcu_[access|dereference]_index_check() APIs with READ_ONCE() and rcu_lockdep_assert().

  - RCU CPU-hotplug cleanups.

  - Updates to Tiny RCU: a race fix and further code shrinkage.

  - RCU torture-testing updates: fixes, speedups, cleanups and
    documentation updates.

  - Miscellaneous fixes.

  - Documentation updates.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-06-02 08:18:34 +02:00
Paul E. McKenney
29c6820f51 mce: mce_chrdev_write() can be static
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-05-27 12:56:17 -07:00
Paul E. McKenney
e90328b87e mce: Stop using array-index-based RCU primitives
Because mce is arch-specific x86 code, there is little or no
performance benefit of using rcu_dereference_index_check() over using
smp_load_acquire().  It also turns out that mce is the only place that
array-index-based RCU is used, and it would be convenient to drop
this portion of the RCU API.

This patch therefore changes rcu_dereference_index_check() uses to
smp_load_acquire(), but keeping the lockdep diagnostics, and also
changes rcu_access_index() uses to READ_ONCE().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: linux-edac@vger.kernel.org
Cc: Tony Luck <tony.luck@intel.com>
Acked-by: Borislav Petkov <bp@suse.de>
2015-05-27 12:56:16 -07:00
Xie XiuQi
5c31b2800d x86/mce: Fix monarch timeout setting through the mce= cmdline option
Using "mce=1,10000000" on the kernel cmdline to change the
monarch timeout does not work. The cause is that get_option()
does parse a subsequent comma in the option string and signals
that with a return value. So we don't need to check for a second
comma ourselves.

Signed-off-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/1432120943-25028-1-git-send-email-xiexiuqi@huawei.com
Link: http://lkml.kernel.org/r/1432628901-18044-19-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-27 14:39:14 +02:00
Borislav Petkov
17fea54bf0 x86/mce: Fix MCE severity messages
Derek noticed that a critical MCE gets reported with the wrong
error type description:

  [Hardware Error]: CPU 34: Machine Check Exception: 5 Bank 9: f200003f000100b0
  [Hardware Error]: RIP !INEXACT! 10:<ffffffff812e14c1> {intel_idle+0xb1/0x170}
  [Hardware Error]: TSC 49587b8e321cb
  [Hardware Error]: PROCESSOR 0:306e4 TIME 1431561296 SOCKET 1 APIC 29
  [Hardware Error]: Some CPUs didn't answer in synchronization
  [Hardware Error]: Machine check: Invalid
				   ^^^^^^^

The last line with 'Invalid' should have printed the high level
MCE error type description we get from mce_severity, i.e.
something like:

  [Hardware Error]: Machine check: Action required: data load error in a user process

this happens due to the fact that mce_no_way_out() iterates over
all MCA banks and possibly overwrites the @msg argument which is
used in the panic printing later.

Change behavior to take the message of only and the (last)
critical MCE it detects.

Reported-by: Derek <denc716@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/1431936437-25286-3-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-18 10:31:22 +02:00
Borislav Petkov
3490c0e45f x86/mce/amd: Zap changelog
It is useless and git history has it all detailed anyway. Update
copyright while at it.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
2015-05-07 12:06:43 +02:00
Aravind Gopalakrishnan
868c00bb59 x86/mce/amd: Rename setup_APIC_mce
'setup_APIC_mce' doesn't give us an indication of why we are
going to program LVT. Make that explicit by renaming it to
setup_APIC_mce_threshold so we know.

No functional change is introduced.

Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: x86-ml <x86@kernel.org>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1430913538-1415-7-git-send-email-Aravind.Gopalakrishnan@amd.com
Signed-off-by: Borislav Petkov <bp@suse.de>
2015-05-07 10:33:40 +02:00
Aravind Gopalakrishnan
24fd78a81f x86/mce/amd: Introduce deferred error interrupt handler
Deferred errors indicate error conditions that were not corrected, but
require no action from S/W (or action is optional).These errors provide
info about a latent UC MCE that can occur when a poisoned data is
consumed by the processor.

Processors that report these errors can be configured to generate APIC
interrupts to notify OS about the error.

Provide an interrupt handler in this patch so that OS can catch these
errors as and when they happen. Currently, we simply log the errors and
exit the handler as S/W action is not mandated.

Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: x86-ml <x86@kernel.org>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1430913538-1415-5-git-send-email-Aravind.Gopalakrishnan@amd.com
Signed-off-by: Borislav Petkov <bp@suse.de>
2015-05-07 10:23:32 +02:00
Aravind Gopalakrishnan
7559e13fb4 x86/mce: Add support for deferred errors on AMD
Deferred errors indicate error conditions that were not corrected, but
those errors have not been consumed yet. They require no action from
S/W (or action is optional). These errors provide info about a latent
uncorrectable MCE that can occur when a poisoned data is consumed by the
processor.

Newer AMD processors can generate deferred errors and can be configured
to generate APIC interrupts on such events.

SUCCOR stands for S/W UnCorrectable error COntainment and Recovery.
It indicates support for data poisoning in HW and deferred error
interrupts.

Add new bitfield to mce_vendor_flags for this. We use this to verify
presence of deferred error interrupts before we enable them in mce_amd.c

While at it, clarify comments in mce_vendor_flags to provide an
indication of usages of the bitfields.

Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: x86-ml <x86@kernel.org>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1430913538-1415-4-git-send-email-Aravind.Gopalakrishnan@amd.com
[ beef up commit message, do CPUID(8000_0007) only once. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
2015-05-06 20:34:31 +02:00
Aravind Gopalakrishnan
6e6e746e33 x86/mce/amd: Collect valid address before logging an error
amd_decode_mce() needs value in m->addr so it can report the error
address correctly. This should be setup in __log_error() before we call
mce_log(). We do this because the error address is an important bit of
information which should be conveyed to userspace.

The correct output then reports proper address, like this:

  [Hardware Error]: Corrected error, no action required.
  [Hardware Error]: CPU:0 (15:60:0) MC0_STATUS [-|CE|-|-|AddrV|-|-|CECC]: 0x840041000028017b
  [Hardware Error]: MC0 Error Address: 0x00001f808f0ff040

Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: x86-ml <x86@kernel.org>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1430913538-1415-3-git-send-email-Aravind.Gopalakrishnan@amd.com
Signed-off-by: Borislav Petkov <bp@suse.de>
2015-05-06 19:49:31 +02:00
Aravind Gopalakrishnan
afdf344e08 x86/mce/amd: Factor out logging mechanism
Refactor the code here to setup struct mce and call mce_log() to log
the error. We're going to reuse this in a later patch as part of the
deferred error interrupt enablement.

No functional change is introduced.

Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: x86-ml <x86@kernel.org>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1430913538-1415-2-git-send-email-Aravind.Gopalakrishnan@amd.com
Signed-off-by: Borislav Petkov <bp@suse.de>
2015-05-06 19:49:20 +02:00
Linus Torvalds
07f2d8c63f Merge branch 'x86-ras-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 RAS changes from Ingo Molnar:
 "The main changes in this cycle were:

   - Simplify the CMCI storm logic on Intel CPUs after yet another
     report about a race in the code (Borislav Petkov)

   - Enable the MCE threshold irq on AMD CPUs by default (Aravind
     Gopalakrishnan)

   - Add AMD-specific MCE-severity grading function.  Further error
     recovery actions will be based on its output (Aravind Gopalakrishnan)

   - Documentation updates (Borislav Petkov)

   - ... assorted fixes and cleanups"

* 'x86-ras-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mce/severity: Fix warning about indented braces
  x86/mce: Define mce_severity function pointer
  x86/mce: Add an AMD severities-grading function
  x86/mce: Reindent __mcheck_cpu_apply_quirks() properly
  x86/mce: Use safe MSR accesses for AMD quirk
  x86/MCE/AMD: Enable thresholding interrupts by default if supported
  x86/MCE: Make mce_panic() fatal machine check msg in the same pattern
  x86/MCE/intel: Cleanup CMCI storm logic
  Documentation/acpi/einj: Correct and streamline text
  x86/MCE/AMD: Drop bogus const modifier from AMD's bank4_names()
2015-04-13 13:33:20 -07:00
Aravind Gopalakrishnan
cee8f5a6c8 x86/mce/severity: Fix warning about indented braces
Dan reported compiler warnings about missing curly braces in
mce_severity_amd(). Reindent the catch-all "return MCE_AR_SEVERITY"
correctly to single tab.

While at it, chain ctx == IN_KERNEL check with mcgstatus check to make
it cleaner, as suggested by Boris.

No functional changes are introduced by this patch.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1427814281-18192-1-git-send-email-Aravind.Gopalakrishnan@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-03 15:20:38 +02:00
Aravind Gopalakrishnan
43eaa2a1ad x86/mce: Define mce_severity function pointer
Rename mce_severity() to mce_severity_intel() and assign the
mce_severity function pointer to mce_severity_amd() during init on AMD.
This way, we can avoid a test to call mce_severity_amd every time we get
into mce_severity(). And it's cleaner to do it this way.

Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Suggested-by: Tony Luck <tony.luck@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Chen Yucong <slaoub@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1427125373-2918-3-git-send-email-Aravind.Gopalakrishnan@amd.com
Signed-off-by: Borislav Petkov <bp@suse.de>
2015-03-24 12:14:15 +01:00
Aravind Gopalakrishnan
bf80bbd7dc x86/mce: Add an AMD severities-grading function
Add a severities function that caters to AMD processors. This allows us
to do some vendor-specific work within the function if necessary.

Also, introduce a vendor flag bitfield for vendor-specific settings. The
severities code uses this to define error scope based on the prescence
of the flags field.

This is based off of work by Boris Petkov.

Testing details:
Fam10h, Model 9h (Greyhound)
Fam15h: Models 0h-0fh (Orochi), 30h-3fh (Kaveri) and 60h-6fh (Carrizo),
Fam16h Model 00h-0fh (Kabini)

Boris:
Intel SNB
AMD K8 (JH-E0)

Signed-off-by: Aravind Gopalakrishnan <aravind.gopalakrishnan@amd.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Chen Yucong <slaoub@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: linux-edac@vger.kernel.org
Link: http://lkml.kernel.org/r/1427125373-2918-2-git-send-email-Aravind.Gopalakrishnan@amd.com
[ Fixup build, clean up comments. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
2015-03-24 12:13:34 +01:00
Borislav Petkov
c9ce871283 x86/mce: Reindent __mcheck_cpu_apply_quirks() properly
Had some strange 3 tabs + 2 chars indentation, probably from me. Fix it.

No code changed:

  # arch/x86/kernel/cpu/mcheck/mce.o:

   text    data     bss     dec     hex filename
  21371    5923     264   27558    6ba6 mce.o.before
  21371    5923     264   27558    6ba6 mce.o.after

md5:
   eb3996c84d15e08ed836f043df2cbb01  mce.o.before.asm
   eb3996c84d15e08ed836f043df2cbb01  mce.o.after.asm

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-edac@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23 10:16:44 +01:00
Jesse Larrew
f77ac507f8 x86/mce: Use safe MSR accesses for AMD quirk
Certain MSRs are only relevant to a kernel in host mode, and kvm had
chosen not to implement these MSRs at all for guests. If a guest kernel
ever tried to access these MSRs, the result was a general protection
fault.

KVM will be separately patched to return 0 when these MSRs are read,
and this patch ensures that MSR accesses are tolerant of exceptions.

Signed-off-by: Jesse Larrew <jesse.larrew@amd.com>
[ Drop {} braces around loop ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Joel Schopp <joel.schopp@amd.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-edac@vger.kernel.org
Link: http://lkml.kernel.org/r/1426262619-5016-1-git-send-email-jesse.larrew@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23 10:16:43 +01:00
Ingo Molnar
fa45a45ca3 Merge tag 'ras_for_3.21' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras into x86/ras
Pull RAS updates from Borislav Petkov:

 "- Enable AMD thresholding IRQ by default if supported. (Aravind Gopalakrishnan)

  - Unify mce_panic() message pattern. (Derek Che)

  - A bit more involved simplification of the CMCI logic after yet another
    report about race condition with the adaptive logic. (Borislav Petkov)

  - ACPI APEI EINJ fleshing out of the user documentation. (Borislav Petkov)

  - Minor cleanup. (Jan Beulich.)"

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-19 13:31:33 +01:00
Aravind Gopalakrishnan
d79f931f1c x86/MCE/AMD: Enable thresholding interrupts by default if supported
We setup APIC vectors for threshold errors if interrupt_capable.
However, we don't set interrupt_enable by default. Rework
threshold_restart_bank() so that when we set up lvt_offset, we also set
IntType to APIC and also enable thresholding interrupts for banks which
support it by default.

User is still allowed to disable interrupts through sysfs.

While at it, check if status is valid before we proceed to log error
using mce_log. This is because, in multi-node platforms, only the NBC
(Node Base Core, i.e. the first core in the node) has valid status info
in its MCA registers. So, the decoding of status values on the non-NBC
leads to noise on kernel logs like so:

  EDAC DEBUG: amd64_inject_write_store: section=0x80000000 word_bits=0x10020001
  [Hardware Error]: Corrected error, no action required.
  [Hardware Error]: CPU:25 (15:2:0) MC4_STATUS[-|CE|-|-|-
  [Hardware Error]: Corrected error, no action required.
  [Hardware Error]: CPU:26 (15:2:0) MC4_STATUS[-|CE|-|-|-
  <...>
  WARNING: CPU: 25 PID: 0 at drivers/edac/amd64_edac.c:2147 decode_bus_error+0x1ba/0x2a0()
  WARNING: CPU: 26 PID: 0 at drivers/edac/amd64_edac.c:2147 decode_bus_error+0x1ba/0x2a0()
  Something is rotten in the state of Denmark.

Suggested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Aravind Gopalakrishnan <aravind.gopalakrishnan@amd.com>
Link: http://lkml.kernel.org/r/1422896561-7695-1-git-send-email-aravind.gopalakrishnan@amd.com
[ Massage commit message. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
2015-02-19 13:24:47 +01:00
Derek Che
8af7043a3c x86/MCE: Make mce_panic() fatal machine check msg in the same pattern
There is another mce_panic call with "Fatal machine check on current CPU" in
the same mce.c file, why not keep them all in same pattern

	mce_panic("Fatal machine check on current CPU", &m, msg);

Signed-off-by: Derek Che <drc@yahoo-inc.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
2015-02-19 13:24:47 +01:00
Borislav Petkov
3f2f0680d1 x86/MCE/intel: Cleanup CMCI storm logic
Initially, this started with the yet another report about a race
condition in the CMCI storm adaptive period length thing. Yes, we have
to admit, it is fragile and error prone. So let's simplify it.

The simpler logic is: now, after we enter storm mode, we go straight to
polling with CMCI_STORM_INTERVAL, i.e. once a second. We remain in storm
mode as long as we see errors being logged while polling.

Theoretically, if we see an uninterrupted error stream, we will remain
in storm mode indefinitely and keep polling the MSRs.

However, when the storm is actually a burst of errors, once we have
logged them all, we back out of it after ~5 mins of polling and no more
errors logged.

If we encounter an error during those 5 minutes, we reset the polling
interval to 5 mins.

Making machine_check_poll() return a bool and denoting whether it has
seen an error or not lets us simplify a bunch of code and move the storm
handling private to mce_intel.c.

Some minor cleanups while at it.

Reported-by: Calvin Owens <calvinowens@fb.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/1417746575-23299-1-git-send-email-calvinowens@fb.com
Signed-off-by: Borislav Petkov <bp@suse.de>
2015-02-19 13:24:25 +01:00
Jan Beulich
2cd4c303a7 x86/MCE/AMD: Drop bogus const modifier from AMD's bank4_names()
The compiler validly warns about it being ignored.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/54C21511020000780005890E@mail.emea.novell.com
Signed-off-by: Borislav Petkov <bp@suse.de>
2015-02-19 12:30:47 +01:00
Linus Torvalds
d96c757efa Fix regression - functions on the mce notifier chain should
not be able to decide that an event should not be logged
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Merge tag 'please-pull-fixmcelog' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras

Pull mcelog regression fix from Tony Luck:
 "Fix regression - functions on the mce notifier chain should not be
  able to decide that an event should not be logged"

* tag 'please-pull-fixmcelog' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras:
  x86/mce: Fix regression. All error records should report via /dev/mcelog
2015-02-17 17:03:07 -08:00
Linus Torvalds
37507717de Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 perf updates from Ingo Molnar:
 "This series tightens up RDPMC permissions: currently even highly
  sandboxed x86 execution environments (such as seccomp) have permission
  to execute RDPMC, which may leak various perf events / PMU state such
  as timing information and other CPU execution details.

  This 'all is allowed' RDPMC mode is still preserved as the
  (non-default) /sys/devices/cpu/rdpmc=2 setting.  The new default is
  that RDPMC access is only allowed if a perf event is mmap-ed (which is
  needed to correctly interpret RDPMC counter values in any case).

  As a side effect of these changes CR4 handling is cleaned up in the
  x86 code and a shadow copy of the CR4 value is added.

  The extra CR4 manipulation adds ~ <50ns to the context switch cost
  between rdpmc-capable and rdpmc-non-capable mms"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86: Add /sys/devices/cpu/rdpmc=2 to allow rdpmc for all tasks
  perf/x86: Only allow rdpmc if a perf_event is mapped
  perf: Pass the event to arch_perf_update_userpage()
  perf: Add pmu callbacks to track event mapping and unmapping
  x86: Add a comment clarifying LDT context switching
  x86: Store a per-cpu shadow copy of CR4
  x86: Clean up cr4 manipulation
2015-02-16 14:58:12 -08:00
Linus Torvalds
e07e0d4cb0 Merge branch 'x86-ras-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 RAS update from Ingo Molnar:
 "The changes in this cycle were:

   - allow mmcfg access to APEI error injection handlers

   - improve MCE error messages

   - smaller cleanups"

* 'x86-ras-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, mce: Fix sparse errors
  x86, mce: Improve timeout error messages
  ACPI, EINJ: Enhance error injection tolerance level
2015-02-09 18:22:04 -08:00
Tony Luck
a2413d8b29 x86/mce: Fix regression. All error records should report via /dev/mcelog
I'm getting complaints from validation teams that have updated their
Linux kernels from ancient versions to current. They don't see the
error logs they expect. I tell the to unload any EDAC drivers[1], and
things start working again.  The problem is that we short-circuit
the logging process if any function on the decoder chain claims to
have dealt with the problem:

	ret = atomic_notifier_call_chain(&x86_mce_decoder_chain, 0, m);
	if (ret == NOTIFY_STOP)
		return;

The logic we used when we added this code was that we did not want
to confuse users with double reports of the same error.

But it turns out users are not confused - they are upset that they
don't see a log where their tools used to find a log.

I could also get into a long description of how the consumer of this
log does more than just decode model specific details of the error.
It keeps counts, tracks thresholds, takes actions and runs scripts
that can alert administrators to problems.

[1] We've recently compounded the problem because the acpi_extlog
driver also registers for this notifier and also returns NOTIFY_STOP.

Signed-off-by: Tony Luck <tony.luck@intel.com>
2015-02-09 09:36:53 -08:00
Andy Lutomirski
375074cc73 x86: Clean up cr4 manipulation
CR4 manipulation was split, seemingly at random, between direct
(write_cr4) and using a helper (set/clear_in_cr4).  Unfortunately,
the set_in_cr4 and clear_in_cr4 helpers also poke at the boot code,
which only a small subset of users actually wanted.

This patch replaces all cr4 access in functions that don't leave cr4
exactly the way they found it with new helpers cr4_set_bits,
cr4_clear_bits, and cr4_set_bits_and_update_boot.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Vince Weaver <vince@deater.net>
Cc: "hillf.zj" <hillf.zj@alibaba-inc.com>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/495a10bdc9e67016b8fd3945700d46cfd5c12c2f.1414190806.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-04 12:10:41 +01:00
Luck, Tony
d4812e169d x86, mce: Get rid of TIF_MCE_NOTIFY and associated mce tricks
We now switch to the kernel stack when a machine check interrupts
during user mode.  This means that we can perform recovery actions
in the tail of do_machine_check()

Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
2015-01-07 07:47:42 -08:00
Andy Lutomirski
9592747538 x86, traps: Track entry into and exit from IST context
We currently pretend that IST context is like standard exception
context, but this is incorrect.  IST entries from userspace are like
standard exceptions except that they use per-cpu stacks, so they are
atomic.  IST entries from kernel space are like NMIs from RCU's
perspective -- they are not quiescent states even if they
interrupted the kernel during a quiescent state.

Add and use ist_enter and ist_exit to track IST context.  Even
though x86_32 has no IST stacks, we track these interrupts the same
way.

This fixes two issues:

 - Scheduling from an IST interrupt handler will now warn.  It would
   previously appear to work as long as we got lucky and nothing
   overwrote the stack frame.  (I don't know of any bugs in this
   that would trigger the warning, but it's good to be on the safe
   side.)

 - RCU handling in IST context was dangerous.  As far as I know,
   only machine checks were likely to trigger this, but it's good to
   be on the safe side.

Note that the machine check handlers appears to have been missing
any context tracking at all before this patch.

Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
2015-01-02 10:22:46 -08:00
Borislav Petkov
83737691e5 x86, mce: Fix sparse errors
Make stuff used in mce.c only, static.

Signed-off-by: Borislav Petkov <bp@suse.de>
2014-12-22 21:04:31 +01:00
Andy Lutomirski
6c80f87ed4 x86, mce: Improve timeout error messages
There are four different possible types of timeouts.  Distinguish
them in the logs to help debug them.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/0fa6d2653a54a01c48b43a3583caf950ea99606e.1419178397.git.luto@amacapital.net
Signed-off-by: Borislav Petkov <bp@suse.de>
2014-12-22 17:47:45 +01:00