From: Wei Li <liwei391@xxxxxxxxxx> [ Upstream commit d61cbb859b45fdb6b4997f2d51834fae41af0e94 ] The segmentation fault can be reproduced as following steps: 1) Executing perf report in tui. 2) Typing '/xxxxx' to filter the symbol to get nothing matched. 3) Pressing enter with no entry selected. Then it will report a segmentation fault. It is caused by the lack of check of browser->he_selection when accessing it's member res_samples in perf_evsel__hists_browse(). These processes are meaningful for specified samples, so we can skip these when nothing is selected. Fixes: 4968ac8fb7c3 ("perf report: Implement browsing of individual samples") Signed-off-by: Wei Li <liwei391@xxxxxxxxxx> Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx> Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx> Tested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx> Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx> Cc: Hanjun Guo <guohanjun@xxxxxxxxxx> Cc: Jin Yao <yao.jin@xxxxxxxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Link: http://lore.kernel.org/lkml/20200612094322.39565-1-liwei391@xxxxxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- tools/perf/ui/browsers/hists.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c index 487e54ef56a98..2101b6b770d81 100644 --- a/tools/perf/ui/browsers/hists.c +++ b/tools/perf/ui/browsers/hists.c @@ -2288,6 +2288,11 @@ static struct thread *hist_browser__selected_thread(struct hist_browser *browser return browser->he_selection->thread; } +static struct res_sample *hist_browser__selected_res_sample(struct hist_browser *browser) +{ + return browser->he_selection ? browser->he_selection->res_samples : NULL; +} + /* Check whether the browser is for 'top' or 'report' */ static inline bool is_report_browser(void *timer) { @@ -3357,16 +3362,16 @@ static int perf_evsel__hists_browse(struct evsel *evsel, int nr_events, &options[nr_options], NULL, NULL, evsel); nr_options += add_res_sample_opt(browser, &actions[nr_options], &options[nr_options], - hist_browser__selected_entry(browser)->res_samples, - evsel, A_NORMAL); + hist_browser__selected_res_sample(browser), + evsel, A_NORMAL); nr_options += add_res_sample_opt(browser, &actions[nr_options], &options[nr_options], - hist_browser__selected_entry(browser)->res_samples, - evsel, A_ASM); + hist_browser__selected_res_sample(browser), + evsel, A_ASM); nr_options += add_res_sample_opt(browser, &actions[nr_options], &options[nr_options], - hist_browser__selected_entry(browser)->res_samples, - evsel, A_SOURCE); + hist_browser__selected_res_sample(browser), + evsel, A_SOURCE); nr_options += add_switch_opt(browser, &actions[nr_options], &options[nr_options]); skip_scripting: -- 2.25.1