perf tools: Free temporary 'sys' string in read_event_files()

For each system in a given pevent, read_event_files() reads in a
temporary 'sys' string.  Be sure to free this string before moving onto
to the next system and/or leaving read_event_files().

Fixes the following coverity complaints:

  Error: RESOURCE_LEAK (CWE-772):

  tools/perf/util/trace-event-read.c:343: overwrite_var: Overwriting
  "sys" in "sys = read_string()" leaks the storage that "sys" points to.

  tools/perf/util/trace-event-read.c:353: leaked_storage: Variable "sys"
  going out of scope leaks the storage it points to.

Signed-off-by: Sanskriti Sharma <sansharm@redhat.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Joe Lawrence <joe.lawrence@redhat.com>
Link: http://lkml.kernel.org/r/1538490554-8161-6-git-send-email-sansharm@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/trace-event-read.c b/tools/perf/util/trace-event-read.c
index a278e1eee5f5d1eb37ca04013e19c805cb57d1d1..add8441de5791a48f918fbe066ef69291a8983ab 100644 (file)
--- a/tools/perf/util/trace-event-read.c
+++ b/tools/perf/util/trace-event-read.c
@@ -347,9 +347,12 @@ static int read_event_files(struct tep_handle *pevent)
                for (x=0; x < count; x++) {
                        size = read8(pevent);
                        ret = read_event_file(pevent, sys, size);
-                       if (ret)
+                       if (ret) {
+                               free(sys);
                                return ret;
+                       }
                }
+               free(sys);
        }
        return 0;
 }