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| author | Yazen Ghannam <yazen.ghannam@amd.com> | 2017-11-06 18:46:32 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-11-07 11:07:50 +0100 |
| commit | d65dfc81bb3894fdb68cbc74bbf5fb48d2354071 (patch) | |
| tree | 30d63ef8df0721357608bda244c836368c92d589 /arch/x86 | |
| parent | 92bb6cb1403015b1b9520332c8f2ad983c220f67 (diff) | |
| download | linux-d65dfc81bb3894fdb68cbc74bbf5fb48d2354071.tar.gz | |
x86/MCE/AMD: Always give panic severity for UC errors in kernel context
The AMD severity grading function was introduced in kernel 4.1. The
current logic can possibly give MCE_AR_SEVERITY for uncorrectable
errors in kernel context. The system may then get stuck in a loop as
memory_failure() will try to handle the bad kernel memory and find it
busy.
Return MCE_PANIC_SEVERITY for all UC errors IN_KERNEL context on AMD
systems.
After:
b2f9d678e28c ("x86/mce: Check for faults tagged in EXTABLE_CLASS_FAULT exception table entries")
was accepted in v4.6, this issue was masked because of the tail-end attempt
at kernel mode recovery in the #MC handler.
However, uncorrectable errors IN_KERNEL context should always be considered
unrecoverable and cause a panic.
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org> # 4.9.x
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>
Fixes: bf80bbd7dcf5 (x86/mce: Add an AMD severities-grading function)
Link: http://lkml.kernel.org/r/20171106174633.13576-1-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kernel/cpu/mcheck/mce-severity.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/arch/x86/kernel/cpu/mcheck/mce-severity.c b/arch/x86/kernel/cpu/mcheck/mce-severity.c index 87cc9ab7a13c..4b8187639c2d 100644 --- a/arch/x86/kernel/cpu/mcheck/mce-severity.c +++ b/arch/x86/kernel/cpu/mcheck/mce-severity.c @@ -245,6 +245,9 @@ static int mce_severity_amd(struct mce *m, int tolerant, char **msg, bool is_exc if (m->status & MCI_STATUS_UC) { + if (ctx == IN_KERNEL) + return MCE_PANIC_SEVERITY; + /* * On older systems where overflow_recov flag is not present, we * should simply panic if an error overflow occurs. If @@ -255,10 +258,6 @@ static int mce_severity_amd(struct mce *m, int tolerant, char **msg, bool is_exc if (mce_flags.smca) return mce_severity_amd_smca(m, ctx); - /* software can try to contain */ - if (!(m->mcgstatus & MCG_STATUS_RIPV) && (ctx == IN_KERNEL)) - return MCE_PANIC_SEVERITY; - /* kill current process */ return MCE_AR_SEVERITY; } else { |