perf_counter: Correct PERF_SAMPLE_RAW output

PERF_SAMPLE_* output switches should unconditionally output the correct format, as they are the only way to unambiguously parse the PERF_EVENT_SAMPLE data. Signed-off-by: Peter Zijlstra <[email protected]> Acked-by: Frederic Weisbecker <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Paul Mackerras <[email protected]> LKML-Reference: <1249896447.17467.74.camel@twins> Signed-off-by: Ingo Molnar <[email protected]>
goeke · Aug 10, 2009 · a044560 · a044560
1 parent c0a8865
commit a044560
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Showing 3 changed files with 28 additions and 7 deletions.
diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h
@@ -369,6 +369,8 @@ enum perf_event_type {
 	 *
 	 *	{ u64			nr,
 	 *	  u64			ips[nr];  } && PERF_SAMPLE_CALLCHAIN
+	 *	{ u32			size;
+	 *	  char                  data[size];}&& PERF_SAMPLE_RAW
 	 * };
 	 */
 	PERF_EVENT_SAMPLE		= 9,

diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
@@ -685,7 +685,8 @@ static void ftrace_profile_##call(proto)				\
 	pc = preempt_count();						\
 									\
 	__data_size = ftrace_get_offsets_##call(&__data_offsets, args); \
-	__entry_size = ALIGN(__data_size + sizeof(*entry), sizeof(u64));\
+	__entry_size = ALIGN(__data_size + sizeof(*entry) + sizeof(u32),\
+			     sizeof(u64));				\
 									\
 	do {								\
 		char raw_data[__entry_size];				\

diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
@@ -2646,7 +2646,6 @@ static void perf_counter_output(struct perf_counter *counter, int nmi,
 		u64 counter;
 	} group_entry;
 	struct perf_callchain_entry *callchain = NULL;
-	struct perf_raw_record *raw = NULL;
 	int callchain_size = 0;
 	u64 time;
 	struct {
@@ -2716,9 +2715,15 @@ static void perf_counter_output(struct perf_counter *counter, int nmi,
 	}
 
 	if (sample_type & PERF_SAMPLE_RAW) {
-		raw = data->raw;
-		if (raw)
-			header.size += raw->size;
+		int size = sizeof(u32);
+
+		if (data->raw)
+			size += data->raw->size;
+		else
+			size += sizeof(u32);
+
+		WARN_ON_ONCE(size & (sizeof(u64)-1));
+		header.size += size;
 	}
 
 	ret = perf_output_begin(&handle, counter, header.size, nmi, 1);
@@ -2784,8 +2789,21 @@ static void perf_counter_output(struct perf_counter *counter, int nmi,
 		}
 	}
 
-	if ((sample_type & PERF_SAMPLE_RAW) && raw)
-		perf_output_copy(&handle, raw->data, raw->size);
+	if (sample_type & PERF_SAMPLE_RAW) {
+		if (data->raw) {
+			perf_output_put(&handle, data->raw->size);
+			perf_output_copy(&handle, data->raw->data, data->raw->size);
+		} else {
+			struct {
+				u32	size;
+				u32	data;
+			} raw = {
+				.size = sizeof(u32),
+				.data = 0,
+			};
+			perf_output_put(&handle, raw);
+		}
+	}
 
 	perf_output_end(&handle);
 }