We log a fake bank 128 MCE to note that we're handling a CPU thermal
event. However, this confuses people into thinking that their hardware
generates MCEs. Hijacking MCA for logging thermal events is a gross
misuse anyway and it shouldn't have been done in the first place. And
besides we have other means for dealing with thermal events which are
much more suitable.

So let's kill the MCE logging part.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Acked-by: NAshok Raj <ashok.raj@intel.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: Yazen Ghannam <Yazen.Ghannam@amd.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/20170105213846.GA12024@gmail.com
Link: http://lkml.kernel.org/r/20170123183514.13356-3-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Intel Xeons from Ivy Bridge onwards support a processor identification
number set in the factory. To the user this is a handy unique number to
identify a particular CPU. Intel can decode this to the fab/production
run to track errors. On systems that have it, include it in the machine
check record. I'm told that this would be helpful for users that run
large data centers with multi-socket servers to keep track of which CPUs
are seeing errors.

Boris:
* Add some clarifying comments and spacing.
* Mask out [63:2] in the disabled-but-not-locked case
* Call the MSR variable "val" for more readability.
Signed-off-by: NTony Luck <tony.luck@intel.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: x86-ml <x86@kernel.org>
Link: http://lkml.kernel.org/r/20161123114855.njguoaygp3qnbkia@pd.tnicSigned-off-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

This moves the last piece of the old hotplug notifier code in MCE to the
new hotplug state machine.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: NBorislav Petkov <bp@alien8.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: rt@linutronix.de
Cc: linux-edac@vger.kernel.org
Link: http://lkml.kernel.org/r/20161110174447.11848-8-bigeasy@linutronix.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

The CPU_ONLINE and CPU_DOWN_PREPARE look fully symmetrical and could be move
to the hotplug state machine.
On a failure during registration we have the tear down callback invoked
(mce_cpu_pre_down()) so there should be no timer around and so no need to need
keep notifier installed (this was the reason according to the comment why the
notifier was registered despite of errors).
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: NBorislav Petkov <bp@alien8.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: rt@linutronix.de
Cc: linux-edac@vger.kernel.org
Link: http://lkml.kernel.org/r/20161110174447.11848-7-bigeasy@linutronix.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Initially I wanted to remove mcheck_cpu_init() from identify_cpu() and let it
become an independent early hotplug callback. The main problem here was that
the init on the boot CPU may happen too late
(device_initcall_sync(mcheck_init_device)) and nobody wanted to risk receiving
and MCE event at boot time leading to a shutdown (if the MCE feature is not yet
enabled).

Here is attempt two: the timming stays as-is but the ordering of the functions
is changed:
- mcheck_cpu_init() (which is run from identify_cpu()) will setup the timer
  struct but won't fire the timer. This is moved to CPU_ONLINE since its
  cleanup part is in CPU_DOWN_PREPARE. So if it is okay to stop the timer early
  in the shutdown phase, it should be okay to start it late in the bring up phase.

- CPU_DOWN_PREPARE disables the MCE feature flags for !INTEL CPUs in
  mce_disable_cpu(). If a failure occures it would be re-enabled on all vendor
  CPUs (including Intel where it was not disabled during shutdown). To keep this
  working I am moving it to CPU_ONLINE. smp_call_function_single() is dropped
  beause the notifier runs nowdays on the target CPU.

- CPU_ONLINE is invoking mce_device_create() + mce_threshold_create_device()
  but its cleanup part is in CPU_DEAD (mce_threshold_remove_device() and
  mce_device_remove()). In order to keep this symmetrical I am moving the clean
  up from CPU_DEAD to CPU_DOWN_PREPARE.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: NBorislav Petkov <bp@alien8.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: rt@linutronix.de
Cc: linux-edac@vger.kernel.org
Link: http://lkml.kernel.org/r/20161110174447.11848-6-bigeasy@linutronix.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

The threshold_cpu_callback callbacks looks like one of the notifier and
its arguments are almost the same. Split this out and have one ONLINE
and one DEAD callback. This will come handy later once the main code
gets changed to use the callback mechanism.
Also, handle threshold_cpu_callback_online() return value so we don't
continue if the function fails.

Boris Petkov removed the callback pointer and replaced it with proper
functions.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: NBorislav Petkov <bp@alien8.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: rt@linutronix.de
Cc: linux-edac@vger.kernel.org
Link: http://lkml.kernel.org/r/20161110174447.11848-5-bigeasy@linutronix.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

If we try a CPU down and fail in the middle then we roll back to the
online state. This means we would perform CPU_ONLINE / mce_device_create()
without invoking CPU_DEAD / mce_device_remove() for the cleanup of what was
allocated in CPU_ONLINE.

Be prepared for this and don't allocate the struct if we have it
already.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: NBorislav Petkov <bp@alien8.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: rt@linutronix.de
Cc: linux-edac@vger.kernel.org
Link: http://lkml.kernel.org/r/20161110174447.11848-4-bigeasy@linutronix.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

We did have logic in the MCE code which would TSC-timestamp an error
record only when it is exact - i.e., when it wasn't detected by polling.
This isn't the case anymore. So let's fix that:

We have a valid TSC timestamp in the error record only when it has been
a precise detection, i.e., either in the #MC handler or in one of the
interrupt handlers (thresholding, deferred, ...).

All other error records still have mce.time which contains the wall
time in order to be able to place the error record in time at least
approximately.

Also, this fixes another bug where machine_check_poll() would clear
mce.tsc unconditionally even if we requested precise MCP_TIMESTAMP
logging.

The proper fix would be to generate timestamp only when it has been
requested and not always. But that would require a more thorough code
audit of all mce_gather_info/mce_setup() users. Add a FIXME for now.
Signed-off-by: NBorislav 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 <tony.luck@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: kernel test robot <xiaolong.ye@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: lkp@01.org
Link: http://lkml.kernel.org/r/20161110131053.kybsijfs5venpjnf@pd.tnicSigned-off-by: NIngo Molnar <mingo@kernel.org>

When there are no error record consumers registered with the kernel, the
only thing that appears in dmesg is something like:

  [  300.000326] mce: [Hardware Error]: Machine check events logged

and the error records are gone. Which is seriously counterproductive.

So let's dump them to dmesg instead, in such a case.
Requested-by: NEric Morton <Eric.Morton@amd.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/20161101120911.13163-4-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Now that workqueue can handle work item queueing from very early
during boot, there is no need to gate schedule_work() with
keventd_up().  Remove it.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: linux-edac@vger.kernel.org

The MCA_ADDR registers on Scalable MCA systems contain the ErrorAddr
in bits [55:0] and the least significant bit of the address in bits
[61:56]. We should extract the valid ErrorAddr bits from the MCA_ADDR
register rather than saving the raw value to struct mce.
Signed-off-by: NYazen Ghannam <Yazen.Ghannam@amd.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1473275643-1721-1-git-send-email-Yazen.Ghannam@amd.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

The MCA_SYND and MCA_IPID registers contain valuable information and
should be included in MCE output. The MCA_SYND register contains
syndrome and other error information, and the MCA_IPID register will
uniquely identify the MCA bank's type without having to rely on system
software.
Signed-off-by: NYazen Ghannam <Yazen.Ghannam@amd.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1472680624-34221-2-git-send-email-Yazen.Ghannam@amd.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

The MCA_IPID register uniquely identifies a bank's type and instance
on Scalable MCA systems. We should save the value of this register
in struct mce along with the other relevant error information. This
ensures that we can decode errors without relying on system software to
correlate the bank to the type.
Signed-off-by: NYazen Ghannam <Yazen.Ghannam@amd.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1472680624-34221-1-git-send-email-Yazen.Ghannam@amd.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Syndrome information is no longer contained in MCA_STATUS for SMCA
systems but in a new register - MCA_SYND.

Add a synd field to struct mce to hold MCA_SYND register value. Add it
to the end of struct mce to maintain compatibility with old versions of
mcelog. Also, add it to the respective tracepoint.
Signed-off-by: NYazen Ghannam <Yazen.Ghannam@amd.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1467633035-32080-1-git-send-email-Yazen.Ghannam@amd.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

We now have a better way to determine if we are running on a cpu that
supports machine check recovery. Free up this feature bit.
Signed-off-by: NTony Luck <tony.luck@intel.com>
Acked-by: NBorislav Petkov <bp@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Boris Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/d5db39e08d46cf1012d94d3902275d08ba931926.1472754712.git.tony.luck@intel.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Each Xeon includes a number of capability registers in PCI space that
describe some features not enumerated by CPUID.

Use these to determine that we are running on a model that can recover from
machine checks. Hooks for Ivybridge ... Skylake provided.
Signed-off-by: NTony Luck <tony.luck@intel.com>
Acked-by: NBorislav Petkov <bp@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Boris Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/abf331dc4a3e2a2d17444129bc51127437bcf4ba.1472754711.git.tony.luck@intel.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

The MSR address we're dumping in there should be in hex, otherwise we
get funsies like:

  [    0.016000] WARNING: CPU: 1 PID: 0 at arch/x86/kernel/cpu/mcheck/mce.c:428 mce_rdmsrl+0xd9/0xe0
  [    0.016000] mce: Unable to read msr -1073733631!
				       ^^^^^^^^^^^
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
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: Josh Poimboeuf <jpoimboe@redhat.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/1467968983-4874-5-git-send-email-bp@alien8.de
[ Fixed capitalization of 'MSR'. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Pinned timers must carry the pinned attribute in the timer structure
itself, so convert the code to the new API.

No functional change.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Chris Mason <clm@fb.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: George Spelvin <linux@sciencehorizons.net>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160704094341.215783439@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Use cpu_has() facilities to find available RAS features rather than
directly reading CPUID 0x80000007_EBX.
Signed-off-by: NYazen Ghannam <Yazen.Ghannam@amd.com>
[ Use the struct cpuinfo_x86 ptr instead. ]
Signed-off-by: NBorislav 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>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1462971509-3856-6-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Check the MCG_STATUS_LMCES bit on Intel to verify that current MCE is
local. It is always local on AMD.
Signed-off-by: NYazen Ghannam <Yazen.Ghannam@amd.com>
[ Massaged it a bit. Reflowed comments. Shut up -Wmaybe-uninitialized. ]
Signed-off-by: NBorislav 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>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1462019637-16474-8-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

A couple of issues here:

1) MCE_LOG_LEN is only 32 - so we may have more pending records than will
   fit in the buffer on high core count CPUs.

2) During a panic we may have a lot of duplicate records because multiple
   logical CPUs may have seen and logged the same error because some
   banks are shared.

Switch to using the genpool to look for the pending records. Squeeze out
duplicated records.
Signed-off-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ashok Raj <ashok.raj@intel.com>
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: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1462019637-16474-7-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Replace all calls to MCx_IA32_{CTL,ADDR,MISC,STATUS} with the
appropriate msr_ops.

Use SMCA-specific msr_ops when on an SMCA-enabled processor.

Carved out from a patch by Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>.
Signed-off-by: NYazen Ghannam <Yazen.Ghannam@amd.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Aravind Gopalakrishnan <aravindksg.lkml@gmail.com>
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>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1462019637-16474-6-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Scalable MCA processors have a whole new range of MSR addresses to
obtain bank related info such as CTL, MISC, ADDR, STATUS. Therefore, we
need a way to abstract the MSR addresses per vendor.

Carved out from a patch by Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>.
Signed-off-by: NYazen Ghannam <Yazen.Ghannam@amd.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Aravind Gopalakrishnan <aravindksg.lkml@gmail.com>
Cc: Ashok Raj <ashok.raj@intel.com>
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>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1462019637-16474-5-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

We need to do this after __mcheck_cpu_init_vendor() as for
ScalableMCA processors, there are going to be new MSR write handlers
if the feature is detected using CPUID bit (which happens in
__mcheck_cpu_init_vendor()).

No functional change is introduced here.
Signed-off-by: NAravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Signed-off-by: NYazen Ghannam <Yazen.Ghannam@amd.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Aravind Gopalakrishnan <aravindksg.lkml@gmail.com>
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>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1462019637-16474-4-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

For Fam17h, we want to report errors that persist across reboots. Error
persistence is dependent on HW and no BIOS currently fiddles with values
here. So allow reporting of errors upon boot until something goes wrong.

Logging is disabled on older families because BIOS didn't clear the MCA
banks after a cold reset.
Signed-off-by: NAravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Signed-off-by: NYazen Ghannam <Yazen.Ghannam@amd.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Aravind Gopalakrishnan <aravindksg.lkml@gmail.com>
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>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1459886686-13977-2-git-send-email-Yazen.Ghannam@amd.com
Link: http://lkml.kernel.org/r/1462019637-16474-2-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

mce_start() has an explicit smp_wmb() to serialize writes to global_nwo
and mce_callin. However, atomic_inc_return() implies barriers on both
sides of the call, as such simply rely on this full SMP barrier.
Signed-off-by: NDavidlohr Bueso <dbueso@suse.de>
Signed-off-by: NBorislav 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>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1458602396-840-1-git-send-email-dave@stgolabs.net
Link: http://lkml.kernel.org/r/1459929916-12852-3-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

The Intel Software Developer Manual describes bit 24 in the MCG_CAP
MSR:

   MCG_SER_P (software error recovery support present) flag,
   bit 24 — Indicates (when set) that the processor supports
   software error recovery

But only some models with this capability bit set will actually
generate recoverable machine checks.

Check the model name and set a synthetic capability bit. Provide
a command line option to set this bit anyway in case the kernel
doesn't recognise the model name.
Signed-off-by: NTony Luck <tony.luck@intel.com>
Reviewed-by: NBorislav 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/2e5bfb23c89800a036fb8a45fa97a74bb16bc362.1455732970.git.tony.luck@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Extend the severity checking code to add a new context IN_KERN_RECOV
which is used to indicate that the machine check was triggered by code
in the kernel tagged with _ASM_EXTABLE_FAULT() so that the ex_handler_fault()
handler will provide the fixup code with the trap number.

Major re-work to the tail code in do_machine_check() to make all this
readable/maintainable. One functional change is that tolerant=3 no longer
stops recovery actions. Revert to only skipping sending SIGBUS to the
current process.
Signed-off-by: NTony Luck <tony.luck@intel.com>
Reviewed-by: NBorislav 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/89d243d05a7943bb187d1074bb30d9c4f482d5f5.1455732970.git.tony.luck@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

In mce_amd_feature_init() we take decisions based on mce_flags
being set or not. So the feature detection using CPUID should
naturally be ordered before we call mce_amd_feature_init().

Fix that here.
Signed-off-by: NAravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Borislav Petkov <bp@alien8.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>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1453750913-4781-4-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

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: NAshok Raj <ashok.raj@intel.com>
[ Massage commit message. ]
Signed-off-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NTony Luck <tony.luck@intel.com>
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: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1449742346-21470-2-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

The MCi_MISC bitfield definitions mce_usable_address() checks
are Intel-only. Make them so.

While at it, move mce_usable_address() up, before all its
callers and get rid of the forward declaration.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Acked-by: NTony Luck <tony.luck@intel.com>
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>
Link: http://lkml.kernel.org/r/1448350880-5573-5-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

We simply need to look at the extended error code when detecting
whether the error is of type memory.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Acked-by: NTony Luck <tony.luck@intel.com>
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>
Link: http://lkml.kernel.org/r/1448350880-5573-4-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

It is useless and we can use the function instead. Besides,
mcelog(8) hasn't managed to make use of it yet. So kill it.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Acked-by: NTony Luck <tony.luck@intel.com>
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>
Link: http://lkml.kernel.org/r/1448350880-5573-3-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

We used to have a special ring buffer for deferred errors that
was used to mark problem pages. We replaced that with a generic
pool. Then later converted mce_log() to also use the same pool.
As a result, we end up adding all deferred errors to the pool
twice.

Rearrange this code. Make sure to set the m.severity and
m.usable_addr fields for deferred errors. Then if flags and
mca_cfg.dont_log_ce mean we call mce_log() we are done, because
that will add this entry to the generic pool.

If we skipped mce_log(), then we still want to take action for
the deferred error, so add to the pool.

Change the name of the boolean "error_logged" to "error_seen",
we should set it whether of not we logged an error because the
return value from machine_check_poll() is used to decide whether
storms have subsided or not.
Reported-by: NGong Chen <gong.chen@linux.intel.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NBorislav 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: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1448350880-5573-2-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Caught by building with W= which enable -Wswitch-default also.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Borislav Petkov <bp@alien8.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/1446207099-24948-3-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Scalable MCA (SMCA) is a new feature in AMD Fam17h processors
which indicates presence of MCA extensions.

MCA extensions expands existing register space for the MCE banks
and also introduces a new MSR range to accommodate new banks.

Add the detection bit.
Signed-off-by: NAravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
[ Reformat mce_vendor_flags definitions and save indentation levels. Improve comments. ]
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
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/1446207099-24948-2-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

It is not safe to clear global MCi_CTL banks during CPU offline
or suspend/resume operations. These MSRs are either
thread-scoped (meaning private to a thread), or core-scoped
(private to threads in that core only), or with a socket scope:
visible and controllable from all threads in the socket.

When we offline a single CPU, clearing those MCi_CTL bits will
stop signaling for all the shared, i.e., socket-wide resources,
such as LLC, iMC, etc.

In addition, it might be possible to compromise the integrity of
an Intel Secure Guard eXtentions (SGX) system if the attacker
has control of the host system and is able to inject errors
which would be otherwise ignored when MCi_CTL bits are cleared.

Hence on SGX enabled systems, if MCi_CTL is cleared, SGX gets
disabled.
Tested-by: NSerge Ayoun <serge.ayoun@intel.com>
Signed-off-by: NAshok Raj <ashok.raj@intel.com>
[ Cleanup text. ]
Signed-off-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NTony Luck <tony.luck@intel.com>
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: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1441391390-16985-1-git-send-email-ashok.raj@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

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: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NBorislav 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.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

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: NBorislav Petkov <bp@suse.de>
Acked-by: NPaul 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.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

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: NAshok Raj <ashok.raj@intel.com>
Signed-off-by: NBorislav 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.deSigned-off-by: NIngo Molnar <mingo@kernel.org>