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| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2010-03-11 15:53:11 -0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2010-03-11 20:00:32 +0100 |
| commit | 9f591fd76afdc0e5192e9ed00a36f8efc0b4dfe6 (patch) | |
| tree | 6692dc95d4d799431a8b403a206660546f066a16 | |
| parent | 639fe4b12f92b54c9c3b38c82cdafaa38cfd3e63 (diff) | |
| download | blackbird-op-linux-9f591fd76afdc0e5192e9ed00a36f8efc0b4dfe6.tar.gz blackbird-op-linux-9f591fd76afdc0e5192e9ed00a36f8efc0b4dfe6.zip | |
perf record: Don't try to find buildids in a zero sized file
Fixing this symptom:
[acme@mica linux-2.6-tip]$ perf record -a -f
Fatal: Permission error - are you root?
Bus error
[acme@mica linux-2.6-tip]$
I.e. if for some reason no data is collected, in this case a non
root user trying to do systemwide profiling, no data will be
collected, and then we end up trying to mmap a zero sized file
and access the file header, b00m.
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: <stable@kernel.org>
LKML-Reference: <1268333592-30872-1-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | tools/perf/builtin-record.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index b09d3b27ca14..3b8b6387c47c 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -395,6 +395,9 @@ static int process_buildids(void) { u64 size = lseek(output, 0, SEEK_CUR); + if (size == 0) + return 0; + session->fd = output; return __perf_session__process_events(session, post_processing_offset, size - post_processing_offset, |
