[PATCH] perf script: Fix segfault using --show-mmap-events

From	Adrian Hunter <adrian.hunter@intel.com>
Newsgroups	linux.kernel
Subject	[PATCH] perf script: Fix segfault using --show-mmap-events
Date	2015-08-20 10:30 +0200
Message-ID	<pZtou-7NR-13@gated-at.bofh.it> (permalink)
Organization	Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki

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Patch "perf script: Don't assume evsel position of tracking events"
changed 'perf script' to use 'perf_evlist__id2evsel()'. That results
in a segfault if there is more than 1 event and there are
synthesized mmap events e.g.

	$ perf record -e cycles,instructions -p$$ sleep 1
	$ perf script --show-mmap-events
	Segmentation fault (core dumped)

That happens because these synthesized events have an 'id' of zero
which does not match any 'evsel'.

Currently, these synthesized events use the sample type of the first
evsel.

Change 'perf_evlist__id2evsel()' to reflect that which also makes
it consistent with 'perf_evlist__event2evsel()'.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 tools/perf/util/evlist.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 373f65b02545..e9a5d432902c 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -573,7 +573,7 @@ struct perf_evsel *perf_evlist__id2evsel(struct perf_evlist *evlist, u64 id)
 {
 	struct perf_sample_id *sid;
 
-	if (evlist->nr_entries == 1)
+	if (evlist->nr_entries == 1 || !id)
 		return perf_evlist__first(evlist);
 
 	sid = perf_evlist__id2sid(evlist, id);
-- 
1.9.1

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[PATCH] perf script: Fix segfault using --show-mmap-events Adrian Hunter <adrian.hunter@intel.com> - 2015-08-20 10:30 +0200
  Re: [PATCH] perf script: Fix segfault using --show-mmap-events Arnaldo Carvalho de Melo <acme@kernel.org> - 2015-08-20 21:30 +0200
  [tip:perf/core] perf script:   Fix segfault using --show-mmap-events tip-bot for Adrian Hunter <tipbot@zytor.com> - 2015-08-22 09:00 +0200

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