perf probe: Fix segfault if passed with ''.

WangNan0 · acmel · commit e59d29e88f7b · 2015-05-05T12:26:52.000-03:00
Since parse_perf_probe_point() deals with a user passed argument, we should not assume it to be a valid string. Without this patch, if pass '' to perf probe, a segfault raises: $ perf probe -a '' Segmentation fault This patch checks argument of parse_perf_probe_point() before string processing. After this patch: $ perf probe -a '' usage: perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...] or: perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...] ... Signed-off-by: Wang Nan <wangnan0@huawei.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Zefan Li <lizefan@huawei.com> Link: http://lkml.kernel.org/r/1430210769-94177-1-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
@@ -1084,6 +1084,8 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
 	 *
 	 * TODO:Group name support
 	 */
+	if (!arg)
+		return -EINVAL;
 
 	ptr = strpbrk(arg, ";=@+%");
 	if (ptr && *ptr == '=') {	/* Event name */

Original file line number	Diff line number	Diff line change
`@@ -1084,6 +1084,8 @@ static int parse_perf_probe_point(char arg, struct perf_probe_event pev)`
`1084`	`1084`	`*`
`1085`	`1085`	`* TODO:Group name support`
`1086`	`1086`	`*/`
	`1087`	`+ if (!arg)`
	`1088`	`+ return -EINVAL;`
`1087`	`1089`
`1088`	`1090`	`ptr = strpbrk(arg, ";=@+%");`
`1089`	`1091`	`if (ptr && ptr == '=') { / Event name */`