From a6293f36ac92ab513771a98efe486477be2f981f Mon Sep 17 00:00:00 2001 From: Stanislav Ivanichkin Date: Tue, 27 Oct 2020 12:43:57 +0300 Subject: [PATCH] perf trace: Fix segfault when trying to trace events by cgroup # ./perf trace -e sched:sched_switch -G test -a sleep 1 perf: Segmentation fault Obtained 11 stack frames. ./perf(sighandler_dump_stack+0x43) [0x55cfdc636db3] /lib/x86_64-linux-gnu/libc.so.6(+0x3efcf) [0x7fd23eecafcf] ./perf(parse_cgroups+0x36) [0x55cfdc673f36] ./perf(+0x3186ed) [0x55cfdc70d6ed] ./perf(parse_options_subcommand+0x629) [0x55cfdc70e999] ./perf(cmd_trace+0x9c2) [0x55cfdc5ad6d2] ./perf(+0x1e8ae0) [0x55cfdc5ddae0] ./perf(+0x1e8ded) [0x55cfdc5ddded] ./perf(main+0x370) [0x55cfdc556f00] /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xe6) [0x7fd23eeadb96] ./perf(_start+0x29) [0x55cfdc557389] Segmentation fault # It happens because "struct trace" in option->value is passed to the parse_cgroups function instead of "struct evlist". Fixes: 9ea42ba4411ac ("perf trace: Support setting cgroups as targets") Signed-off-by: Stanislav Ivanichkin Tested-by: Arnaldo Carvalho de Melo Acked-by: Namhyung Kim Cc: Dmitry Monakhov Link: http://lore.kernel.org/lkml/20201027094357.94881-1-sivanichkin@yandex-team.ru Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-trace.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index 44a75f2..de80534 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -4639,9 +4639,9 @@ do_concat: err = 0; if (lists[0]) { - struct option o = OPT_CALLBACK('e', "event", &trace->evlist, "event", - "event selector. use 'perf list' to list available events", - parse_events_option); + struct option o = { + .value = &trace->evlist, + }; err = parse_events_option(&o, lists[0], 0); } out: @@ -4655,9 +4655,12 @@ static int trace__parse_cgroups(const struct option *opt, const char *str, int u { struct trace *trace = opt->value; - if (!list_empty(&trace->evlist->core.entries)) - return parse_cgroups(opt, str, unset); - + if (!list_empty(&trace->evlist->core.entries)) { + struct option o = { + .value = &trace->evlist, + }; + return parse_cgroups(&o, str, unset); + } trace->cgroup = evlist__findnew_cgroup(trace->evlist, str); return 0; -- 2.7.4