[RFC PATCH 01/22] perf: probe: avoid segfault if passed with ''.

Wang Nan
2015-04-30T10:53:36Z

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>
---
tools/perf/util/probe-event.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index d8bb616..d05b77c 100644
--- 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 */
--
1.8.3.4