From: Borislav Petkov <[email protected]>
3.4.109-rc1 review patch. If anyone has any objections, please let me know.
------------------
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 <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Tony Luck <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <[email protected]>
---
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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