Re: [PATCH] perf hists browser: Fix segfault when all entries be filtered

From: He Kuang
Date: Mon Mar 09 2015 - 23:39:29 EST


ping..
On 2015/3/4 12:13, He Kuang wrote:
When all perf report entries be filtered, the result of
hists__filter_entries() can be NULL, check the result before processing.

Miss this checking will cause segmentation fault like this:

$ perf report

(filter all entries and left nothing, then zoom in/out)
perf: Segmentation fault
-------- backtrace --------
../bin/perf[0x4d1858]
../lib64/libc.so.6(+0x3545f)[0x7fe72fc1145f]
../bin/perf[0x4cd9f5]
../bin/perf[0x4ce176]
../bin/perf[0x4d0506]
../bin/perf[0x41a94f]
../bin/perf[0x408cf2]
../bin/perf[0x408455]
../lib64/libc.so.6(__libc_start_main+0xf4)[0x7fe72fbfdbd4]
../bin/perf[0x408584]

Signed-off-by: He Kuang <hekuang@xxxxxxxxxx>
---
tools/perf/ui/browsers/hists.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
index 788506e..1106bb8 100644
--- a/tools/perf/ui/browsers/hists.c
+++ b/tools/perf/ui/browsers/hists.c
@@ -992,6 +992,9 @@ static void ui_browser__hists_seek(struct ui_browser *browser,
* and stop when we printed enough lines to fill the screen.
*/
do_offset:
+ if (!nd)
+ return;
+
if (offset > 0) {
do {
h = rb_entry(nd, struct hist_entry, rb_node);


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