This is a note to let you know that I've just added the patch titled
x86/mce: Pay no attention to 'F' bit in MCACOD when parsing 'UC' errors
to the 3.11-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-mce-pay-no-attention-to-f-bit-in-mcacod-when-parsing-uc-errors.patch
and it can be found in the queue-3.11 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 0ca06c0857aee11911f91621db14498496f2c2cd Mon Sep 17 00:00:00 2001
From: Tony Luck <tony.luck@xxxxxxxxx>
Date: Wed, 24 Jul 2013 13:54:20 -0700
Subject: x86/mce: Pay no attention to 'F' bit in MCACOD when parsing 'UC' errors
From: Tony Luck <tony.luck@xxxxxxxxx>
commit 0ca06c0857aee11911f91621db14498496f2c2cd upstream.
The 0x1000 bit of the MCACOD field of machine check MCi_STATUS
registers is only defined for corrected errors (where it means
that hardware may be filtering errors see SDM section 15.9.2.1).
For uncorrected errors it may, or may not be set - so we should mask
it out when checking for the architecturaly defined recoverable
error signatures (see SDM 15.9.3.1 and 15.9.3.2)
Acked-by: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/mce.h | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -32,11 +32,20 @@
#define MCI_STATUS_PCC (1ULL<<57) /* processor context corrupt */
#define MCI_STATUS_S (1ULL<<56) /* Signaled machine check */
#define MCI_STATUS_AR (1ULL<<55) /* Action required */
-#define MCACOD 0xffff /* MCA Error Code */
+
+/*
+ * Note that the full MCACOD field of IA32_MCi_STATUS MSR is
+ * bits 15:0. But bit 12 is the 'F' bit, defined for corrected
+ * errors to indicate that errors are being filtered by hardware.
+ * We should mask out bit 12 when looking for specific signatures
+ * of uncorrected errors - so the F bit is deliberately skipped
+ * in this #define.
+ */
+#define MCACOD 0xefff /* MCA Error Code */
/* Architecturally defined codes from SDM Vol. 3B Chapter 15 */
#define MCACOD_SCRUB 0x00C0 /* 0xC0-0xCF Memory Scrubbing */
-#define MCACOD_SCRUBMSK 0xfff0
+#define MCACOD_SCRUBMSK 0xeff0 /* Skip bit 12 ('F' bit) */
#define MCACOD_L3WB 0x017A /* L3 Explicit Writeback */
#define MCACOD_DATA 0x0134 /* Data Load */
#define MCACOD_INSTR 0x0150 /* Instruction Fetch */
Patches currently in stable-queue which might be from tony.luck@xxxxxxxxx are
queue-3.11/x86-mce-pay-no-attention-to-f-bit-in-mcacod-when-parsing-uc-errors.patch
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