perf annotate: Check null of sym pointer before using it

Sym may be NULL, and that will cause perf to crash.

Signed-off-by: Shan Wei <davidshan@tencent.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/4FCD95D3.90209@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/tools/perf/ui/browsers/annotate.c b/tools/perf/ui/browsers/annotate.c
index 34b1c46eaf42..67a2703e666a 100644
--- a/tools/perf/ui/browsers/annotate.c
+++ b/tools/perf/ui/browsers/annotate.c
@@ -814,7 +814,7 @@ int symbol__tui_annotate(struct symbol *sym, struct map *map, int evidx,
 {
         struct disasm_line *pos, *n;
         struct annotation *notes;
-        const size_t size = symbol__size(sym);
+        size_t size;
         struct map_symbol ms = {
                 .map = map,
                 .sym = sym,
@@ -834,6 +834,8 @@ int symbol__tui_annotate(struct symbol *sym, struct map *map, int evidx,
         if (sym == NULL)
                 return -1;
 
+        size = symbol__size(sym);
+
         if (map->dso->annotate_warned)
                 return -1;