perf evsel: Fix uninitialized memory access to struct perf_sample

Memory in struct perf_sample is not fully initialized during parsing.
Depending on sampling data some parts may left unchanged. Zero out
struct perf_sample first to avoid access to uninitialized memory.

Cc: Ingo Molnar <mingo@elte.hu>
Link: http://lkml.kernel.org/r/1323966762-8574-2-git-send-email-robert.richter@amd.com
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/evsel.c

@@ -460,7 +460,7 @@ int perf_event__parse_sample(const union perf_event *event, u64 type,
 		u32 val32[2];
 	} u;
 
-
+	memset(data, 0, sizeof(*data));
 	data->cpu = data->pid = data->tid = -1;
 	data->stream_id = data->id = data->time = -1ULL;