[PATCH 1/2] perf probe: Only call probe_file__get_events() when fd is valid

[Wang Nan <wangnan0@huawei.com>]

In system with kprobe enabled but uprobe turned off, 'perf probe -d'
causes segfault because it calls probe_file__get_events() with a
negative fd (when deleting uprobe events).

This patch validates fds before calling probe_file__get_events().

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-probe.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
index 132afc9..861aa89 100644
--- a/tools/perf/builtin-probe.c
+++ b/tools/perf/builtin-probe.c
@@ -384,7 +384,11 @@ static int perf_del_probe_events(struct strfilter *filter)
 		goto out;
 	}
 
-	ret = probe_file__get_events(kfd, filter, klist);
+	if (kfd < 0)
+		ret = -ENOENT;
+	else
+		ret = probe_file__get_events(kfd, filter, klist);
+
 	if (ret == 0) {
 		strlist__for_each(ent, klist)
 			pr_info("Removed event: %s\n", ent->s);
@@ -394,7 +398,11 @@ static int perf_del_probe_events(struct strfilter *filter)
 			goto error;
 	}
 
-	ret2 = probe_file__get_events(ufd, filter, ulist);
+	if (ufd < 0)
+		ret2 = -ENOENT;
+	else
+		ret2 = probe_file__get_events(ufd, filter, ulist);
+
 	if (ret2 == 0) {
 		strlist__for_each(ent, ulist)
 			pr_info("Removed event: %s\n", ent->s);
-- 
1.8.3.4