[PATCH 2/3] tracing: Fix synthetic event to allow semicolon at end

[Steven Rostedt]

From: Masami Hiramatsu <mhiramat@xxxxxxxxxx>

Fix synthetic event to allow independent semicolon at end.

The synthetic_events interface accepts a semicolon after the
last word if there is no space.

 # echo "myevent u64 var;" >> synthetic_events

But if there is a space, it returns an error.

 # echo "myevent u64 var ;" > synthetic_events
 sh: write error: Invalid argument

This behavior is difficult for users to understand. Let's
allow the last independent semicolon too.

Link: 153986835420.18251.2191216690677025744.stgit@devbox">http://lkml.kernel.org/r/153986835420.18251.2191216690677025744.stgit@devbox

Cc: Shuah Khan <shuah@xxxxxxxxxx>
Cc: Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Fixes: commit 4b147936fa50 ("tracing: Add support for 'synthetic' events")
Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
 kernel/trace/trace_events_hist.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 6ff83941065a..d239004aaf29 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -1088,7 +1088,7 @@ static int create_synth_event(int argc, char **argv)
 		i += consumed - 1;
 	}
 
-	if (i < argc) {
+	if (i < argc && strcmp(argv[i], ";") != 0) {
 		ret = -EINVAL;
 		goto err;
 	}
-- 
2.19.0