perf tools: Fixup mmap event consumption
The tail position of the event buffer should only be modified after
actually use that event.
If not the event buffer could be invalid before use, and segment fault
occurs when invoking perf top -G.
Signed-off-by: Zhouyi Zhou <yizhouzhou@ict.ac.cn>
Cc: David Ahern <dsahern@gmail.com>
Cc: Zhouyi Zhou <yizhouzhou@ict.ac.cn>
Link: http://lkml.kernel.org/r/1382600613-32177-1-git-send-email-zhouzhouyi@gmail.com
[ Simplified the logic using exit gotos and renamed write_tail method to mmap_consume ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 71aa3e3..99c8d9a 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -987,7 +987,7 @@
err = perf_evlist__parse_sample(evlist, event, &sample);
if (err) {
fprintf(trace->output, "Can't parse sample, err = %d, skipping...\n", err);
- continue;
+ goto next_event;
}
if (trace->base_time == 0)
@@ -1001,18 +1001,20 @@
evsel = perf_evlist__id2evsel(evlist, sample.id);
if (evsel == NULL) {
fprintf(trace->output, "Unknown tp ID %" PRIu64 ", skipping...\n", sample.id);
- continue;
+ goto next_event;
}
if (sample.raw_data == NULL) {
fprintf(trace->output, "%s sample with no payload for tid: %d, cpu %d, raw_size=%d, skipping...\n",
perf_evsel__name(evsel), sample.tid,
sample.cpu, sample.raw_size);
- continue;
+ goto next_event;
}
handler = evsel->handler.func;
handler(trace, evsel, &sample);
+next_event:
+ perf_evlist__mmap_consume(evlist, i);
if (done)
goto out_unmap_evlist;