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Commit fead35c6 authored by Yazen Ghannam's avatar Yazen Ghannam Committed by Ingo Molnar
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x86/mce: Detect local MCEs properly 



Check the MCG_STATUS_LMCES bit on Intel to verify that current MCE is
local. It is always local on AMD.

Signed-off-by: default avatarYazen Ghannam <Yazen.Ghannam@amd.com>
[ Massaged it a bit. Reflowed comments. Shut up -Wmaybe-uninitialized. ]
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
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>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1462019637-16474-8-git-send-email-bp@alien8.de


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 5541c93c

arch/x86/kernel/cpu/mcheck/mce.c

+20 −13
Original line number Diff line number Diff line
@@ -1038,11 +1038,12 @@ void do_machine_check(struct pt_regs *regs, long error_code) 
	int i;

	int worst = 0;

	int severity;



	/*

	 * Establish sequential order between the CPUs entering the machine

	 * check handler.

	 */

	int order;

	int order = -1;

	/*

	 * If no_way_out gets set, there is no safe way to recover from this

	 * MCE.  If mca_cfg.tolerant is cranked up, we'll try anyway.
@@ -1056,7 +1057,12 @@ void do_machine_check(struct pt_regs *regs, long error_code) 
	DECLARE_BITMAP(toclear, MAX_NR_BANKS);

	DECLARE_BITMAP(valid_banks, MAX_NR_BANKS);

	char *msg = "Unknown";

	int lmce = 0;



	/*

	 * MCEs are always local on AMD. Same is determined by MCG_STATUS_LMCES

	 * on Intel.

	 */

	int lmce = 1;



	/* If this CPU is offline, just bail out. */

	if (cpu_is_offline(smp_processor_id())) {
@@ -1095,19 +1101,20 @@ void do_machine_check(struct pt_regs *regs, long error_code) 
		kill_it = 1;



	/*

	 * Check if this MCE is signaled to only this logical processor

	 * Check if this MCE is signaled to only this logical processor,

	 * on Intel only.

	 */

	if (m.mcgstatus & MCG_STATUS_LMCES)

		lmce = 1;

	else {

	if (m.cpuvendor == X86_VENDOR_INTEL)

		lmce = m.mcgstatus & MCG_STATUS_LMCES;



	/*

		 * Go through all the banks in exclusion of the other CPUs.

		 * This way we don't report duplicated events on shared banks

		 * because the first one to see it will clear it.

		 * If this is a Local MCE, then no need to perform rendezvous.

	 * Go through all banks in exclusion of the other CPUs. This way we

	 * don't report duplicated events on shared banks because the first one

	 * to see it will clear it. If this is a Local MCE, then no need to

	 * perform rendezvous.

	 */

	if (!lmce)

		order = mce_start(&no_way_out);

	}



	for (i = 0; i < cfg->banks; i++) {

		__clear_bit(i, toclear);