perf hists: Fix comparing of dynamic entries

When hist_entry__cmp() and hist_entry__collapse() are called, they
should check if the dynamic entry is comparing matching hists only.

Otherwise it might access different hists resulting in incorrect output.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1456512767-1164-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/hist.c

@@ -1002,6 +1002,10 @@ hist_entry__cmp(struct hist_entry *left, struct hist_entry *right)
 	int64_t cmp = 0;
 
 	hists__for_each_sort_list(hists, fmt) {
+		if (perf_hpp__is_dynamic_entry(fmt) &&
+		    !perf_hpp__defined_dynamic_entry(fmt, hists))
+			continue;
+
 		cmp = fmt->cmp(fmt, left, right);
 		if (cmp)
 			break;
@@ -1018,6 +1022,10 @@ hist_entry__collapse(struct hist_entry *left, struct hist_entry *right)
 	int64_t cmp = 0;
 
 	hists__for_each_sort_list(hists, fmt) {
+		if (perf_hpp__is_dynamic_entry(fmt) &&
+		    !perf_hpp__defined_dynamic_entry(fmt, hists))
+			continue;
+
 		cmp = fmt->collapse(fmt, left, right);
 		if (cmp)
 			break;