perf record: Allocate area for sample_id_hdr in a synthesized comm event
A previous patch added a synthesized comm event for forked child process
but it missed that the event should contain area for sample_id_hdr at
the end. It worked by accident since the perf_event union contains
bigger event structs like mmap_events.
This patch fixes it by dynamically allocating event struct including
those area like in perf_event__synthesize_thread_map().
Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1443577526-3240-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index a01c8ae..5e01c07 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -637,17 +637,25 @@
* Let the child rip
*/
if (forks) {
- union perf_event event;
+ union perf_event *event;
+
+ event = malloc(sizeof(event->comm) + machine->id_hdr_size);
+ if (event == NULL) {
+ err = -ENOMEM;
+ goto out_child;
+ }
+
/*
* Some H/W events are generated before COMM event
* which is emitted during exec(), so perf script
* cannot see a correct process name for those events.
* Synthesize COMM event to prevent it.
*/
- perf_event__synthesize_comm(tool, &event,
+ perf_event__synthesize_comm(tool, event,
rec->evlist->workload.pid,
process_synthesized_event,
machine);
+ free(event);
perf_evlist__start_workload(rec->evlist);
}