[tip:perfcounters/urgent] perf annotate: Fix segmentation fault

tip-bot for Ingo Molnar
2009-08-18T12:07:23Z

Commit-ID: 15f3fa4e7f608c5ce19187b3b4a953222fdfa751
Gitweb: http://git.kernel.org/tip/15f3fa4e7f608c5ce19187b3b4a953222fdfa751
Author: Ingo Molnar <mingo@elte.hu>
AuthorDate: Tue, 18 Aug 2009 13:52:28 +0200
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Tue, 18 Aug 2009 14:00:52 +0200

perf annotate: Fix segmentation fault

Linus reported this perf annotate segfault:

[torvalds@nehalem git]$ perf annotate unmap_vmas
Segmentation fault

#0 map__clone (self=<value optimized out>) at builtin-annotate.c:236
#1 thread__fork (self=<value optimized out>) at builtin-annotate.c:372

The bug here was that builtin-annotate.c was a copy of
builtin-report.c and a threading related fix to builtin-report.c
didnt get propagated to builtin-annotate.c ...

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

---
tools/perf/builtin-annotate.c | 7 +++++++
1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c
index 1dba568..343e7b1 100644
--- a/tools/perf/builtin-annotate.c
+++ b/tools/perf/builtin-annotate.c
@@ -980,6 +980,13 @@ process_fork_event(event_t *event, unsigned long offset, unsigned long head)
(void *)(long)(event->header.size),
event->fork.pid, event->fork.ppid);

+ /*
+ * A thread clone will have the same PID for both
+ * parent and child.
+ */
+ if (thread == parent)
+ return 0;
+
if (!thread || !parent || thread__fork(thread, parent)) {
dprintf("problem processing PERF_EVENT_FORK, skipping event.\n");
return -1;