From 3a03005ff9445834f3d3b577a11bcbdbdf7a89cf Mon Sep 17 00:00:00 2001 From: Yunlong Song Date: Fri, 13 Feb 2015 21:11:52 +0800 Subject: [PATCH] perf tools: Fix a bug of segmentation fault Fix the 'segmentation fault' bug of 'perf list --list-cmds', which also happens in other cases (e.g. record, report ...). This bug happens when there are no cmds to list at all. Example: Before this patch: $ perf list --list-cmds Segmentation fault $ After this patch: $ perf list --list-cmds $ As shown above, the result prints nothing rather than a segmentation fault. The null result means 'perf list' has no cmds to display at this time. Signed-off-by: Yunlong Song Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/r/1423833115-11199-5-git-send-email-yunlong.song@huawei.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/parse-options.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/parse-options.c b/tools/perf/util/parse-options.c index 4a015f77e2b5b..4ee9a86705ed3 100644 --- a/tools/perf/util/parse-options.c +++ b/tools/perf/util/parse-options.c @@ -510,8 +510,10 @@ int parse_options_subcommand(int argc, const char **argv, const struct option *o } exit(130); case PARSE_OPT_LIST_SUBCMDS: - for (int i = 0; subcommands[i]; i++) - printf("%s ", subcommands[i]); + if (subcommands) { + for (int i = 0; subcommands[i]; i++) + printf("%s ", subcommands[i]); + } exit(130); default: /* PARSE_OPT_UNKNOWN */ if (ctx.argv[0][1] == '-') {