perf hists: Add extra integrity checks to fmt_free()

Make sure the struct perf_hpp_fmt is properly unhooked before we free
it.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Changbin Du <changbin.du@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20171013083736.15037-3-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/tools/perf/ui/hist.c b/tools/perf/ui/hist.c
index 6ee6b36bbc76..db79017a6e56 100644
--- a/tools/perf/ui/hist.c
+++ b/tools/perf/ui/hist.c
@@ -606,6 +606,13 @@ next:
 
 static void fmt_free(struct perf_hpp_fmt *fmt)
 {
+        /*
+         * At this point fmt should be completely
+         * unhooked, if not it's a bug.
+         */
+        BUG_ON(!list_empty(&fmt->list));
+        BUG_ON(!list_empty(&fmt->sort_list));
+
         if (fmt->free)
                 fmt->free(fmt);
 }