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authorChen, Gong <gong.chen@linux.intel.com>2015-08-12 16:29:37 (GMT)
committerIngo Molnar <mingo@kernel.org>2015-08-13 08:12:51 (GMT)
commitf29a7aff4bd60ebc3da4982f80144a4158c4c74a (patch)
tree1403d279016fbaba44d00cb98e038b439fc50d65
parentfd4cf79fcc4b5130ced8fd8c40378d3cec2e5fa8 (diff)
downloadlinux-f29a7aff4bd60ebc3da4982f80144a4158c4c74a.tar.xz
x86/mce: Avoid potential deadlock due to printk() in MCE context
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>
-rw-r--r--arch/x86/kernel/cpu/mcheck/mce-apei.c1
-rw-r--r--arch/x86/kernel/cpu/mcheck/mce.c4
-rw-r--r--arch/x86/kernel/cpu/mcheck/mce_intel.c1
3 files changed, 2 insertions, 4 deletions
diff --git a/arch/x86/kernel/cpu/mcheck/mce-apei.c b/arch/x86/kernel/cpu/mcheck/mce-apei.c
index a1aef95..34c89a3 100644
--- a/arch/x86/kernel/cpu/mcheck/mce-apei.c
+++ b/arch/x86/kernel/cpu/mcheck/mce-apei.c
@@ -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);
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 8260369..9568bb5 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -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);
diff --git a/arch/x86/kernel/cpu/mcheck/mce_intel.c b/arch/x86/kernel/cpu/mcheck/mce_intel.c
index 844f56c..70f567f 100644
--- a/arch/x86/kernel/cpu/mcheck/mce_intel.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_intel.c
@@ -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();
}
/*