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x86/mce: Avoid potential deadlock due to printk() in MCE context

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Printing in MCE context is a no-no, currently, as printk() is
not NMI-safe. If some of the notifiers on the MCE chain call do
so, we may deadlock. In order to avoid that, delay printk() to
process context where it is safe.

Reported-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Chen, Gong <gong.chen@linux.intel.com>
[ Fold in subsequent patch from Boris for early boot logging. ]
Signed-off-by: Tony Luck <tony.luck@intel.com>
[ Kick irq_work in mce_log() directly. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1439396985-12812-6-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Chen, Gong 2015-08-12 18:29:37 +02:00 committed by Ingo Molnar
parent fd4cf79fcc
commit f29a7aff4b
3 changed files with 2 additions and 4 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

1
arch/x86/kernel/cpu/mcheck/mce-apei.c
View file

@ -57,7 +57,6 @@ void apei_mce_report_mem_error(int severity, struct cper_sec_mem_err *mem_err)
m.addr = mem_err->physical_addr;
mce_log(&m);
mce_notify_irq();
}
EXPORT_SYMBOL_GPL(apei_mce_report_mem_error);

4
arch/x86/kernel/cpu/mcheck/mce.c
View file

@ -159,7 +159,8 @@ void mce_log(struct mce *mce)
/* Emit the trace record: */
trace_mce_record(mce);
atomic_notifier_call_chain(&x86_mce_decoder_chain, 0, mce);
if (!mce_gen_pool_add(mce))
irq_work_queue(&mce_irq_work);
mce->finished = 0;
wmb();
@ -1122,7 +1123,6 @@ void do_machine_check(struct pt_regs *regs, long error_code)
/* assuming valid severity level != 0 */
m.severity = severity;
m.usable_addr = mce_usable_address(&m);
mce_gen_pool_add(&m);
mce_log(&m);

1
arch/x86/kernel/cpu/mcheck/mce_intel.c
View file

@ -246,7 +246,6 @@ static void intel_threshold_interrupt(void)
return;
machine_check_poll(MCP_TIMESTAMP, this_cpu_ptr(&mce_banks_owned));
mce_notify_irq();
}
/*