path: root/tools
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authorArnaldo Carvalho de Melo <acme@redhat.com>2010-03-11 15:53:11 -0300
committerIngo Molnar <mingo@elte.hu>2010-03-11 20:00:32 +0100
commit9f591fd76afdc0e5192e9ed00a36f8efc0b4dfe6 (patch)
tree6692dc95d4d799431a8b403a206660546f066a16 /tools
parent639fe4b12f92b54c9c3b38c82cdafaa38cfd3e63 (diff)
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>
Diffstat (limited to 'tools')
1 files changed, 3 insertions, 0 deletions
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index b09d3b27ca1..3b8b6387c47 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,