From: Arnaldo Carvalho de Melo <acme@redhat.com>
Date: Tue, 1 Mar 2011 13:21:44 +0000 (-0300)
Subject: perf top browser: Handle empty active symbols list
X-Git-Tag: android-x86-4.4-r1~6927^2~44
X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=3166fc8fb6a2f52273d545e970297524e02c3e39;p=android-x86%2Fkernel.git

perf top browser: Handle empty active symbols list

Fixing a SEGV. An empty list could happen when not being able to resolve
symbols, for instance when --vmlinux invalid-file is used.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---

diff --git a/tools/perf/util/ui/browsers/top.c b/tools/perf/util/ui/browsers/top.c
index e9381ec9bfb1..5a06538532af 100644
--- a/tools/perf/util/ui/browsers/top.c
+++ b/tools/perf/util/ui/browsers/top.c
@@ -76,6 +76,12 @@ static void perf_top_browser__update_rb_tree(struct perf_top_browser *browser)
 	browser->root = RB_ROOT;
 	browser->b.top = NULL;
 	browser->sum_ksamples = perf_top__decay_samples(top, &browser->root);
+	/*
+ 	 * No active symbols
+ 	 */
+	if (top->rb_entries == 0)
+		return;
+
 	perf_top__find_widths(top, &browser->root, &browser->dso_width,
 			      &browser->dso_short_width,
                               &browser->sym_width);