1 files changed, 78 insertions, 4 deletions

diff --git a/arch/x86/kernel/cpu/mcheck/mce-severity.c b/arch/x86/kernel/cpu/mcheck/mce-severity.c
index c189e89..4f4d2ca 100644
--- a/arch/x86/kernel/cpu/mcheck/mce-severity.c
+++ b/arch/x86/kernel/cpu/mcheck/mce-severity.c
@@ -19,43 +19,117 @@
  * first. Since there are quite a lot of combinations test the bits in a
  * table-driven way. The rules are simply processed in order, first
  * match wins.
+ *
+ * Note this is only used for machine check exceptions, the corrected
+ * errors use much simpler rules. The exceptions still check for the corrected
+ * errors, but only to leave them alone for the CMCI handler (except for
+ * panic situations)
  */
 
+enum context { IN_KERNEL = 1, IN_USER = 2 };
+enum ser { SER_REQUIRED = 1, NO_SER = 2 };
+
 static struct severity {
 	u64 mask;
 	u64 result;
 	unsigned char sev;
 	unsigned char mcgmask;
 	unsigned char mcgres;
+	unsigned char ser;
+	unsigned char context;
 	char *msg;
 } severities[] = {
+#define KERNEL .context = IN_KERNEL
+#define USER .context = IN_USER
+#define SER .ser = SER_REQUIRED
+#define NOSER .ser = NO_SER
 #define SEV(s) .sev = MCE_ ## s ## _SEVERITY
 #define BITCLR(x, s, m, r...) { .mask = x, .result = 0, SEV(s), .msg = m, ## r }
 #define BITSET(x, s, m, r...) { .mask = x, .result = x, SEV(s), .msg = m, ## r }
 #define MCGMASK(x, res, s, m, r...) \
 	{ .mcgmask = x, .mcgres = res, SEV(s), .msg = m, ## r }
+#define MASK(x, y, s, m, r...) \
+	{ .mask = x, .result = y, SEV(s), .msg = m, ## r }
+#define MCI_UC_S (MCI_STATUS_UC|MCI_STATUS_S)
+#define MCI_UC_SAR (MCI_STATUS_UC|MCI_STATUS_S|MCI_STATUS_AR)
+#define MCACOD 0xffff
+
 	BITCLR(MCI_STATUS_VAL, NO, "Invalid"),
 	BITCLR(MCI_STATUS_EN, NO, "Not enabled"),
 	BITSET(MCI_STATUS_PCC, PANIC, "Processor context corrupt"),
-	MCGMASK(MCG_STATUS_RIPV, 0, PANIC, "No restart IP"),
+	/* When MCIP is not set something is very confused */
+	MCGMASK(MCG_STATUS_MCIP, 0, PANIC, "MCIP not set in MCA handler"),
+	/* Neither return not error IP -- no chance to recover -> PANIC */
+	MCGMASK(MCG_STATUS_RIPV|MCG_STATUS_EIPV, 0, PANIC,
+		"Neither restart nor error IP"),
+	MCGMASK(MCG_STATUS_RIPV, 0, PANIC, "In kernel and no restart IP",
+		KERNEL),
+	BITCLR(MCI_STATUS_UC, KEEP, "Corrected error", NOSER),
+	MASK(MCI_STATUS_OVER|MCI_STATUS_UC|MCI_STATUS_EN, MCI_STATUS_UC, SOME,
+	     "Spurious not enabled", SER),
+
+	/* ignore OVER for UCNA */
+	MASK(MCI_UC_SAR, MCI_STATUS_UC, KEEP,
+	     "Uncorrected no action required", SER),
+	MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_STATUS_UC|MCI_STATUS_AR, PANIC,
+	     "Illegal combination (UCNA with AR=1)", SER),
+	MASK(MCI_STATUS_S, 0, KEEP, "Non signalled machine check", SER),
+
+	/* AR add known MCACODs here */
+	MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_STATUS_OVER|MCI_UC_SAR, PANIC,
+	     "Action required with lost events", SER),
+	MASK(MCI_STATUS_OVER|MCI_UC_SAR|MCACOD, MCI_UC_SAR, PANIC,
+	     "Action required; unknown MCACOD", SER),
+
+	/* known AO MCACODs: */
+	MASK(MCI_UC_SAR|MCI_STATUS_OVER|0xfff0, MCI_UC_S|0xc0, AO,
+	     "Action optional: memory scrubbing error", SER),
+	MASK(MCI_UC_SAR|MCI_STATUS_OVER|MCACOD, MCI_UC_S|0x17a, AO,
+	     "Action optional: last level cache writeback error", SER),
+
+	MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_UC_S, SOME,
+	     "Action optional unknown MCACOD", SER),
+	MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_UC_S|MCI_STATUS_OVER, SOME,
+	     "Action optional with lost events", SER),
 	BITSET(MCI_STATUS_UC|MCI_STATUS_OVER, PANIC, "Overflowed uncorrected"),
 	BITSET(MCI_STATUS_UC, UC, "Uncorrected"),
 	BITSET(0, SOME, "No match")	/* always matches. keep at end */
 };
 
+/*
+ * If the EIPV bit is set, it means the saved IP is the
+ * instruction which caused the MCE.
+ */
+static int error_context(struct mce *m)
+{
+	if (m->mcgstatus & MCG_STATUS_EIPV)
+		return (m->ip && (m->cs & 3) == 3) ? IN_USER : IN_KERNEL;
+	/* Unknown, assume kernel */
+	return IN_KERNEL;
+}
+
 int mce_severity(struct mce *a, int tolerant, char **msg)
 {
+	enum context ctx = error_context(a);
 	struct severity *s;
+
 	for (s = severities;; s++) {
 		if ((a->status & s->mask) != s->result)
 			continue;
 		if ((a->mcgstatus & s->mcgmask) != s->mcgres)
 			continue;
-		if (s->sev > MCE_NO_SEVERITY && (a->status & MCI_STATUS_UC) &&
-			tolerant < 1)
-			return MCE_PANIC_SEVERITY;
+		if (s->ser == SER_REQUIRED && !mce_ser)
+			continue;
+		if (s->ser == NO_SER && mce_ser)
+			continue;
+		if (s->context && ctx != s->context)
+			continue;
 		if (msg)
 			*msg = s->msg;
+		if (s->sev >= MCE_UC_SEVERITY && ctx == IN_KERNEL) {
+			if (panic_on_oops || tolerant < 1)
+				return MCE_PANIC_SEVERITY;
+		}
 		return s->sev;
 	}
 }