[PATCH v0 00/12] x86/mce: Correct the noinstr annotation

From: Borislav Petkov
Date: Thu Nov 04 2021 - 10:40:52 EST


From: Borislav Petkov <bp@xxxxxxx>

Hi,

here's a first preliminary (it is based on some random 5.16-rc0 commit
and is tested only in qemu) of the series which correct all the noinstr
annotation of the #MC handler.

Since it calls a bunch of external facilities, the strategy is to mark
mce-specific functions called by the #MC handler as noinstr and when
they "call out" so to speak, to do a begin/end sandwich around that
call.

Please have a look and let me know if it looks ok-ish.

Further testing will happen after -rc1 releases, thus the "v0" version
here.

Thx.

Borislav Petkov (12):
x86/mce: Do not use memset to clear the banks bitmaps
x86/mce: Remove function-local cpus variables
x86/mce: Use mce_rdmsrl() in severity checking code
x86/mce: Remove noinstr annotation from mce_setup()
x86/mce: Allow instrumentation during task work queueing
x86/mce: Prevent severity computation from being instrumented
x86/mce: Mark mce_panic() noinstr
x86/mce: Mark mce_end() noinstr
x86/mce: Mark mce_read_aux() noinstr
x86/mce: Move the tainting outside of the noinstr region
x86/mce: Mark mce_timed_out() noinstr
x86/mce: Mark mce_start() noinstr

arch/x86/kernel/cpu/mce/core.c | 108 +++++++++++++++++++----------
arch/x86/kernel/cpu/mce/internal.h | 2 +
arch/x86/kernel/cpu/mce/severity.c | 37 ++++++----
3 files changed, 98 insertions(+), 49 deletions(-)

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2.29.2