There are two implemented bits in the PPIN_CTL MSR:

Bit 0: LockOut (R/WO)
      Set 1 to prevent further writes to MSR_PPIN_CTL.

Bit 1: Enable_PPIN (R/W)
       If 1, enables MSR_PPIN to be accessible using RDMSR.
       If 0, an attempt to read MSR_PPIN will cause #GP.

So there are four defined values:
	0: PPIN is disabled, PPIN_CTL may be updated
	1: PPIN is disabled. PPIN_CTL is locked against updates
	2: PPIN is enabled. PPIN_CTL may be updated
	3: PPIN is enabled. PPIN_CTL is locked against updates

Code would only enable the X86_FEATURE_INTEL_PPIN feature for case "2".
When it should have done so for both case "2" and case "3".

Fix the final test to just check for the enable bit. Also fix some of
the other comments in this function.

Fixes: 3f5a7896a509 ("x86/mce: Include the PPIN in MCE records when available")
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20200226011737.9958-1-tony.luck@intel.com

Chris Wilson reported splats from running the thermal throttling
workqueue callback on offlined CPUs. The problem is that that callback
should not even run on offlined CPUs but it happens nevertheless because
the offlining callback thermal_throttle_offline() does not symmetrically
undo the setup work done in its onlining counterpart. IOW,

 1. The thermal interrupt vector should be masked out before ...

 2. ... cancelling any pending work synchronously so that no new work is
 enqueued anymore.

Do those things and fix the issue properly.

 [ bp: Write commit message. ]

Fixes: f6656208f04e ("x86/mce/therm_throt: Optimize notifications of thermal throttle")
Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Tested-by: Pandruvada, Srinivas <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/158120068234.18291.7938335950259651295@skylake-alporthouse-com

Accessing the MCA thresholding controls in sysfs concurrently with CPU
hotplug can lead to a couple of KASAN-reported issues:

  BUG: KASAN: use-after-free in sysfs_file_ops+0x155/0x180
  Read of size 8 at addr ffff888367578940 by task grep/4019

and

  BUG: KASAN: use-after-free in show_error_count+0x15c/0x180
  Read of size 2 at addr ffff888368a05514 by task grep/4454

for example. Both result from the fact that the threshold block
creation/teardown code frees the descriptor memory itself instead of
defining proper ->release function and leaving it to the driver core to
take care of that, after all sysfs accesses have completed.

Do that and get rid of the custom freeing code, fixing the above UAFs in
the process.

  [ bp: write commit message. ]

Fixes: 95268664390b ("[PATCH] x86_64: mce_amd support for family 0x10 processors")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20200214082801.13836-1-bp@alien8.de

threshold_create_bank() creates a bank descriptor per MCA error
thresholding counter which can be controlled over sysfs. It publishes
the pointer to that bank in a per-CPU variable and then goes on to
create additional thresholding blocks if the bank has such.

However, that creation of additional blocks in
allocate_threshold_blocks() can fail, leading to a use-after-free
through the per-CPU pointer.

Therefore, publish that pointer only after all blocks have been setup
successfully.

Fixes: 019f34fccfd5 ("x86, MCE, AMD: Move shared bank to node descriptor")
Reported-by: Saar Amar <Saar.Amar@microsoft.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200128140846.phctkvx5btiexvbx@kili.mountain

Pull x86 cpu-features updates from Ingo Molnar:
 "The biggest change in this cycle was a large series from Sean
  Christopherson to clean up the handling of VMX features. This both
  fixes bugs/inconsistencies and makes the code more coherent and
  future-proof.

  There are also two cleanups and a minor TSX syslog messages
  enhancement"

* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  x86/cpu: Remove redundant cpu_detect_cache_sizes() call
  x86/cpu: Print "VMX disabled" error message iff KVM is enabled
  KVM: VMX: Allow KVM_INTEL when building for Centaur and/or Zhaoxin CPUs
  perf/x86: Provide stubs of KVM helpers for non-Intel CPUs
  KVM: VMX: Use VMX_FEATURE_* flags to define VMCS control bits
  KVM: VMX: Check for full VMX support when verifying CPU compatibility
  KVM: VMX: Use VMX feature flag to query BIOS enabling
  KVM: VMX: Drop initialization of IA32_FEAT_CTL MSR
  x86/cpufeatures: Add flag to track whether MSR IA32_FEAT_CTL is configured
  x86/cpu: Set synthetic VMX cpufeatures during init_ia32_feat_ctl()
  x86/cpu: Print VMX flags in /proc/cpuinfo using VMX_FEATURES_*
  x86/cpu: Detect VMX features on Intel, Centaur and Zhaoxin CPUs
  x86/vmx: Introduce VMX_FEATURES_*
  x86/cpu: Clear VMX feature flag if VMX is not fully enabled
  x86/zhaoxin: Use common IA32_FEAT_CTL MSR initialization
  x86/centaur: Use common IA32_FEAT_CTL MSR initialization
  x86/mce: WARN once if IA32_FEAT_CTL MSR is left unlocked
  x86/intel: Initialize IA32_FEAT_CTL MSR at boot
  tools/x86: Sync msr-index.h from kernel sources
  selftests, kvm: Replace manual MSR defs with common msr-index.h
  ...

Pull RAS updates from Borislav Petkov:

 - Misc fixes to the MCE code all over the place, by Jan H. Schönherr.

 - Initial support for AMD F19h and other cleanups to amd64_edac, by
   Yazen Ghannam.

 - Other small cleanups.

* 'ras-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  EDAC/mce_amd: Make fam_ops static global
  EDAC/amd64: Drop some family checks for newer systems
  EDAC/amd64: Add family ops for Family 19h Models 00h-0Fh
  x86/amd_nb: Add Family 19h PCI IDs
  EDAC/mce_amd: Always load on SMCA systems
  x86/MCE/AMD, EDAC/mce_amd: Add new Load Store unit McaType
  x86/mce: Fix use of uninitialized MCE message string
  x86/mce: Fix mce=nobootlog
  x86/mce: Take action on UCNA/Deferred errors again
  x86/mce: Remove mce_inject_log() in favor of mce_log()
  x86/mce: Pass MCE message to mce_panic() on failed kernel recovery
  x86/mce/therm_throt: Mark throttle_active_work() as __maybe_unused

Add support for a new version of the Load Store unit bank type as
indicated by its McaType value, which will be present in future SMCA
systems.

Add the new (HWID, MCATYPE) tuple. Reuse the same name, since this is
logically the same to the user.

Also, add the new error descriptions to edac_mce_amd.

Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200110015651.14887-2-Yazen.Ghannam@amd.com

It is relatively easy to trigger the following boot splat on an Ice Lake
client platform. The call stack is like:

  kernel BUG at kernel/timer/timer.c:1152!

  Call Trace:
  __queue_delayed_work
  queue_delayed_work_on
  therm_throt_process
  intel_thermal_interrupt
  ...

The reason is that a CPU's thermal interrupt is enabled prior to
executing its hotplug onlining callback which will initialize the
throttling workqueues.

Such a race can lead to therm_throt_process() accessing an uninitialized
therm_work, leading to the above BUG at a very early bootup stage.

Therefore, unmask the thermal interrupt vector only after having setup
the workqueues completely.

 [ bp: Heavily massage commit message and correct comment formatting. ]

Fixes: f6656208f04e ("x86/mce/therm_throt: Optimize notifications of thermal throttle")
Signed-off-by: Chuansheng Liu <chuansheng.liu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20200107004116.59353-1-chuansheng.liu@intel.com

WARN if the IA32_FEAT_CTL MSR is somehow left unlocked now that CPU
initialization unconditionally locks the MSR.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20191221044513.21680-6-sean.j.christopherson@intel.com

As pointed out by Boris, the defines for bits in IA32_FEATURE_CONTROL
are quite a mouthful, especially the VMX bits which must differentiate
between enabling VMX inside and outside SMX (TXT) operation.  Rename the
MSR and its bit defines to abbreviate FEATURE_CONTROL as FEAT_CTL to
make them a little friendlier on the eyes.

Arguably, the MSR itself should keep the full IA32_FEATURE_CONTROL name
to match Intel's SDM, but a future patch will add a dedicated Kconfig,
file and functions for the MSR. Using the full name for those assets is
rather unwieldy, so bite the bullet and use IA32_FEAT_CTL so that its
nomenclature is consistent throughout the kernel.

Opportunistically, fix a few other annoyances with the defines:

  - Relocate the bit defines so that they immediately follow the MSR
    define, e.g. aren't mistaken as belonging to MISC_FEATURE_CONTROL.
  - Add whitespace around the block of feature control defines to make
    it clear they're all related.
  - Use BIT() instead of manually encoding the bit shift.
  - Use "VMX" instead of "VMXON" to match the SDM.
  - Append "_ENABLED" to the LMCE (Local Machine Check Exception) bit to
    be consistent with the kernel's verbiage used for all other feature
    control bits.  Note, the SDM refers to the LMCE bit as LMCE_ON,
    likely to differentiate it from IA32_MCG_EXT_CTL.LMCE_EN.  Ignore
    the (literal) one-off usage of _ON, the SDM is simply "wrong".

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20191221044513.21680-2-sean.j.christopherson@intel.com