Messages in this thread Patch in this message | | | From | Arnaldo Carvalho de Melo <> | Subject | [PATCH 1/2] perf record: Don't try to find buildids in a zero sized file | Date | Thu, 11 Mar 2010 15:53:11 -0300 |
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From: Arnaldo Carvalho de Melo <acme@redhat.com>
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> 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 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> --- 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 f573bbb..3bf1409 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -394,6 +394,9 @@ 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, -- 1.5.5.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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