From 443f8c75e8d58d394b0e65b47e02e5cd8ed32b41 Mon Sep 17 00:00:00 2001
From: Jiri Olsa <jolsa@redhat.com>
Date: Mon, 26 Oct 2015 14:51:30 +0100
Subject: perf symbols: Fix endless loop in dso__split_kallsyms_for_kcore

Currently we split symbols based on the map comparison, but symbols are stored
within dso objects and maps could point into same dso objects (kernel maps).

Hence we could end up changing rbtree we are currently iterating and mess it
up. It's easily reproduced on s390x by running:

  $ perf record -a -- sleep 3
  $ perf buildid-list -i perf.data --with-hits

The fix is to compare dso objects instead.

Reported-by: Michael Petlan <mpetlan@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20151026135130.GA26003@krava.brq.redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 71bf711..b4cc766 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -680,7 +680,7 @@ static int dso__split_kallsyms_for_kcore(struct dso *dso, struct map *map,
 			pos->start -= curr_map->start - curr_map->pgoff;
 			if (pos->end)
 				pos->end -= curr_map->start - curr_map->pgoff;
-			if (curr_map != map) {
+			if (curr_map->dso != map->dso) {
 				rb_erase_init(&pos->rb_node, root);
 				symbols__insert(
 					&curr_map->dso->symbols[curr_map->type],
-- 
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