Patch "perf probe: Return errno when not hitting any event" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

perf probe: Return errno when not hitting any event

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
perf-probe-return-errno-when-not-hitting-any-event.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Kefeng Wang <[email protected]>
Date: Fri, 17 Mar 2017 16:16:32 +0800
Subject: perf probe: Return errno when not hitting any event

From: Kefeng Wang <[email protected]>

[ Upstream commit 70946723eeb859466f026274b29c6196e39149c4 ]

On old perf, when using 'perf probe -d' to delete an inexistent event, it returns errno, eg,

-bash-4.3# perf probe -d xxx || echo $?
Info: Event "*:xxx" does not exist.
Error: Failed to delete events.
255

But now perf_del_probe_events() will always set ret = 0, different from previous del_perf_probe_events(). After this, it returns errno again, eg,

-bash-4.3# ./perf probe -d xxx || echo $?
"xxx" does not hit any event.
Error: Failed to delete events.
254

And it is more appropriate to return -ENOENT instead of -EPERM.

---
 tools/perf/builtin-probe.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

@@ -405,9 +405,9 @@ static int perf_del_probe_events(struct
 	}
 
 	if (ret == -ENOENT && ret2 == -ENOENT)
-		pr_debug("\"%s\" does not hit any event.\n", str);
-		/* Note that this is silently ignored */
-	ret = 0;
+		pr_warning("\"%s\" does not hit any event.\n", str);
+	else
+		ret = 0;
 
 error:
 	if (kfd >= 0)

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/perf-probe-return-errno-when-not-hitting-any-event.patch