perf_counter: tool: handle 0-length data files

Avoid perf-report barfing on 0-length data files.

[ Impact: fix perf-report SIGBUS ]

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090501102533.196245693@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 5 insertions, 0 deletions

diff --git a/Documentation/perf_counter/perf-report.cc b/Documentation/perf_counter/perf-report.cc
index 933a07544534..911d7f3e7a65 100644
--- a/Documentation/perf_counter/perf-report.cc
+++ b/Documentation/perf_counter/perf-report.cc
@@ -402,6 +402,11 @@ int main(int argc, char *argv[])
                 exit(-1);
         }
 
+        if (!stat.st_size) {
+                fprintf(stderr, "zero-sized file, nothing to do!\n");
+                exit(0);
+        }
+
         load_kallsyms();
 
 remap: