[PATCH 1/3] mce: Add a msg string to the MCE tracepoint

[Borislav Petkov <bp@amd64.org>]

From: Borislav Petkov <borislav.petkov@amd.com>

The idea here is to pass an additional decoded MCE message through
the tracepoint and into the ring buffer for userspace to consume. The
designated consumers are RAS daemons and other tools collecting RAS
information.

Drop unneeded fields while at it, thus saving some room in the ring
buffer.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
---
 arch/x86/kernel/cpu/mcheck/mce.c |    2 +-
 include/trace/events/mce.h       |   22 +++++++---------------
 2 files changed, 8 insertions(+), 16 deletions(-)

diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 5a11ae2e9e91..072e020ecaf3 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -144,7 +144,7 @@ void mce_log(struct mce *mce)
 	int ret = 0;
 
 	/* Emit the trace record: */
-	trace_mce_record(mce);
+	trace_mce_record("", mce);
 
 	ret = atomic_notifier_call_chain(&x86_mce_decoder_chain, 0, mce);
 	if (ret == NOTIFY_STOP)
diff --git a/include/trace/events/mce.h b/include/trace/events/mce.h
index 4cbbcef6baa8..5fada9a40708 100644
--- a/include/trace/events/mce.h
+++ b/include/trace/events/mce.h
@@ -10,11 +10,12 @@
 
 TRACE_EVENT(mce_record,
 
-	TP_PROTO(struct mce *m),
+	TP_PROTO(const char *msg, struct mce *m),
 
-	TP_ARGS(m),
+	TP_ARGS(msg, m),
 
 	TP_STRUCT__entry(
+		__string(	msg,		msg		)
 		__field(	u64,		mcgcap		)
 		__field(	u64,		mcgstatus	)
 		__field(	u64,		status		)
@@ -24,15 +25,12 @@ TRACE_EVENT(mce_record,
 		__field(	u64,		tsc		)
 		__field(	u64,		walltime	)
 		__field(	u32,		cpu		)
-		__field(	u32,		cpuid		)
-		__field(	u32,		apicid		)
-		__field(	u32,		socketid	)
 		__field(	u8,		cs		)
 		__field(	u8,		bank		)
-		__field(	u8,		cpuvendor	)
 	),
 
 	TP_fast_assign(
+		__assign_str(msg,	msg);
 		__entry->mcgcap		= m->mcgcap;
 		__entry->mcgstatus	= m->mcgstatus;
 		__entry->status		= m->status;
@@ -42,25 +40,19 @@ TRACE_EVENT(mce_record,
 		__entry->tsc		= m->tsc;
 		__entry->walltime	= m->time;
 		__entry->cpu		= m->extcpu;
-		__entry->cpuid		= m->cpuid;
-		__entry->apicid		= m->apicid;
-		__entry->socketid	= m->socketid;
 		__entry->cs		= m->cs;
 		__entry->bank		= m->bank;
-		__entry->cpuvendor	= m->cpuvendor;
 	),
 
-	TP_printk("CPU: %d, MCGc/s: %llx/%llx, MC%d: %016Lx, ADDR/MISC: %016Lx/%016Lx, RIP: %02x:<%016Lx>, TSC: %llx, PROCESSOR: %u:%x, TIME: %llu, SOCKET: %u, APIC: %x",
+	TP_printk("%s" HW_ERR "CPU: %d, MCGc/s: %llx/%llx, MC%d: %016Lx, ADDR/MISC: %016Lx/%016Lx, RIP: %02x:<%016Lx>, TSC: %llx, TIME: %llu)",
+		__get_str(msg),
 		__entry->cpu,
 		__entry->mcgcap, __entry->mcgstatus,
 		__entry->bank, __entry->status,
 		__entry->addr, __entry->misc,
 		__entry->cs, __entry->ip,
 		__entry->tsc,
-		__entry->cpuvendor, __entry->cpuid,
-		__entry->walltime,
-		__entry->socketid,
-		__entry->apicid)
+		__entry->walltime)
 );
 
 #endif /* _TRACE_MCE_H */
-- 
1.7.8.rc0