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| author | Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> | 2009-08-26 09:20:36 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-08-26 20:21:11 +0200 |
| commit | 680b6cfd3cee30a7d997d49430fb73af84523853 (patch) | |
| tree | b1ba1c3acb3611fc84aaaa5d5216a64db3b6a06e /arch/x86/kernel/cpu | |
| parent | x86, mce: Fake panic support for MCE testing (diff) | |
| download | linux-680b6cfd3cee30a7d997d49430fb73af84523853.tar.xz linux-680b6cfd3cee30a7d997d49430fb73af84523853.zip | |
x86, mce: CE in last bank prevents panic by unknown MCE
If MCE handler is called but none of mces_seen have machine
check event which might signal the MCE (i.e. event higher than
MCE_KEEP_SEVERITY), panic with "Machine check from unknown
source" will be taken since the MCE is assumed to be signaled
from external agent or so.
Usually mces_seen never point MCE_KEEP_SEVERITY event such as
CE. But it can happen because initial value of mces_seen is
accidentally modified by mce_no_way_out() - in case if
mce_no_way_out() run through all banks and the last bank has
the CE, mces_seen points the CE and the "panic by unknown" will
not be taken.
This patch fixes this undesired behavior, and clarifies the logic.
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Dongming <jin.dongming@np.css.fujitsu.com>
LKML-Reference: <4A94E244.3020301@jp.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reported-by: Jin Dongming <jin.dongming@np.css.fujitsu.com>
Diffstat (limited to 'arch/x86/kernel/cpu')
| -rw-r--r-- | arch/x86/kernel/cpu/mcheck/mce.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index 54bd1b2fb4c0..325559d1aa58 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -612,7 +612,7 @@ out: * This way we prevent any potential data corruption in a unrecoverable case * and also makes sure always all CPU's errors are examined. * - * Also this detects the case of an machine check event coming from outer + * Also this detects the case of a machine check event coming from outer * space (not detected by any CPUs) In this case some external agent wants * us to shut down, so panic too. * @@ -665,7 +665,7 @@ static void mce_reign(void) * No machine check event found. Must be some external * source or one CPU is hung. Panic. */ - if (!m && tolerant < 3) + if (global_worst <= MCE_KEEP_SEVERITY && tolerant < 3) mce_panic("Machine check from unknown source", NULL, NULL); /* @@ -889,11 +889,11 @@ void do_machine_check(struct pt_regs *regs, long error_code) mce_setup(&m); m.mcgstatus = mce_rdmsrl(MSR_IA32_MCG_STATUS); - no_way_out = mce_no_way_out(&m, &msg); - final = &__get_cpu_var(mces_seen); *final = m; + no_way_out = mce_no_way_out(&m, &msg); + barrier(); /* |