| From | lizf@kernel ... | Subject | [PATCH 3.4 111/146] x86/mce: Fix MCE severity messages | Date | Tue, 15 Sep 2015 17:03:46 +0800 |
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From: Borislav Petkov <bp@suse.de>
3.4.109-rc1 review patch. If anyone has any objections, please let me know.
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commit 17fea54bf0ab34fa09a06bbde2f58ed7bbdf9299 upstream.
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: 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> [lizf: Backported to 3.4: adjust context] Signed-off-by: Zefan Li <lizefan@huawei.com> --- arch/x86/kernel/cpu/mcheck/mce.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index 0d2db0e..9eeaed4 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -652,11 +652,14 @@ EXPORT_SYMBOL_GPL(machine_check_poll); static int mce_no_way_out(struct mce *m, char **msg) { int i; + char *tmp; for (i = 0; i < banks; i++) { m->status = mce_rdmsrl(MSR_IA32_MCx_STATUS(i)); - if (mce_severity(m, tolerant, msg) >= MCE_PANIC_SEVERITY) + if (mce_severity(m, tolerant, &tmp) >= MCE_PANIC_SEVERITY) { + *msg = tmp; return 1; + } } return 0; } -- 1.9.1
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