From 4938cf0c7a62025bbfbf3db7bcdcc2c33312bedb Mon Sep 17 00:00:00 2001 From: Wang Nan Date: Mon, 7 Dec 2015 02:35:44 +0000 Subject: [PATCH] perf hists browser: Fix segfault if use symbol filter in cmdline If feed perf a symbol filter in cmdline and the result is empty, pressing 'Enter' in the hist browser causes crash: # ./perf report perf.data <-- Common mistake for beginners Then press 'Enter': perf: Segmentation fault -------- backtrace -------- /home/wangnan/perf[0x53e578] /lib64/libc.so.6(+0x3545f)[0x7f76bafe045f] /home/wangnan/perf[0x539dd4] /home/wangnan/perf(perf_evlist__tui_browse_hists+0x96)[0x53d216] /home/wangnan/perf(cmd_report+0x1b9f)[0x442c7f] /home/wangnan/perf[0x47efa2] /home/wangnan/perf(main+0x5f5)[0x432fa5] /lib64/libc.so.6(__libc_start_main+0xf4)[0x7f76bafccbd4] /home/wangnan/perf[0x4330d4] This is because 'perf.data' is interpreted as a symbol filter, and the result is empty, so selection is empty. However, hist_browser__toggle_fold() forgets to check it. This patch simply return false when selection is NULL. Signed-off-by: Wang Nan Acked-by: Namhyung Kim Tested-by: Arnaldo Carvalho de Melo Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1449455746-41952-2-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo --- 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 84c8251f39a1..81def6c3f24b 100644 --- a/tools/perf/ui/browsers/hists.c +++ b/tools/perf/ui/browsers/hists.c @@ -298,6 +298,9 @@ static bool hist_browser__toggle_fold(struct hist_browser *browser) struct callchain_list *cl = container_of(ms, struct callchain_list, ms); bool has_children; + if (!he || !ms) + return false; + if (ms == &he->ms) has_children = hist_entry__toggle_fold(he); else -- 2.39.5