perf tools: Fix out-of-bound access to struct perf_session

If filename is NULL there is an out-of-bound access to struct
perf_session if it would be used with perf_session__open(). Shouldn't
actually happen in current implementation as filename is always !NULL.
Fixing this by always null-terminating filename.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1323248577-11268-3-git-send-email-robert.richter@amd.com
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

2 files changed, 2 insertions, 2 deletions

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index d9318d8a9ba1..ea17dfb85baa 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -107,7 +107,7 @@ struct perf_session *perf_session__new(const char *filename, int mode,
                                        bool force, bool repipe,
                                        struct perf_tool *tool)
 {
-        size_t len = filename ? strlen(filename) + 1 : 0;
+        size_t len = filename ? strlen(filename) : 0;
         struct perf_session *self = zalloc(sizeof(*self) + len);
 
         if (self == NULL)
diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
index fb696124ad61..37bc38381fb6 100644
--- a/tools/perf/util/session.h
+++ b/tools/perf/util/session.h
@@ -50,7 +50,7 @@ struct perf_session {
         int                     cwdlen;
         char                    *cwd;
         struct ordered_samples  ordered_samples;
-        char                    filename[0];
+        char                    filename[1];
 };
 
 struct perf_tool;