perf record: Fix segfault with --no-mmap-pages

Adrian reported a segfault when using --no-out-pages:

$ tools/perf/perf record -vv --no-out-pages uname
Segmentation fault (core dumped)

The same occurs with --no-mmap-pages. Fix by checking that str is
non-NULL before parsing it.

Signed-off-by: David Ahern <dsahern@gmail.com>
Reported-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1384267617-3446-2-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 99dc58e5dcc3..3960560f873a 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -719,6 +719,9 @@ int perf_evlist__parse_mmap_pages(const struct option *opt, const char *str,
                 { .tag  = 0 },
         };
 
+        if (str == NULL)
+                return -1;
+
         val = parse_tag_value(str, tags);
         if (val != (unsigned long) -1) {
                 /* we got file size value */