Patch "ring-buffer: Fix return value check in test_ringbuffer()" 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

ring-buffer: Fix return value check in test_ringbuffer()

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:
ring-buffer-fix-return-value-check-in-test_ringbuffer.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: Wei Yongjun <[email protected]>
Date: Fri, 17 Jun 2016 17:33:59 +0000
Subject: ring-buffer: Fix return value check in test_ringbuffer()

From: Wei Yongjun <[email protected]>

commit 62277de758b155dc04b78f195a1cb5208c37b2df upstream.

In case of error, the function kthread_run() returns ERR_PTR() and never returns NULL. The NULL test in the return value check should be replaced with IS_ERR().

---
 kernel/trace/ring_buffer.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

@@ -4875,9 +4875,9 @@ static __init int test_ringbuffer(void)
 		rb_data[cpu].cnt = cpu;
 		rb_threads[cpu] = kthread_create(rb_test, &rb_data[cpu],
 						 "rbtester/%d", cpu);
-		if (WARN_ON(!rb_threads[cpu])) {
+		if (WARN_ON(IS_ERR(rb_threads[cpu]))) {
 			pr_cont("FAILED\n");
-			ret = -1;
+			ret = PTR_ERR(rb_threads[cpu]);
 			goto out_free;
 		}
 

@@ -4887,9 +4887,9 @@ static __init int test_ringbuffer(void)
 
 	/* Now create the rb hammer! */
 	rb_hammer = kthread_run(rb_hammer_test, NULL, "rbhammer");
-	if (WARN_ON(!rb_hammer)) {
+	if (WARN_ON(IS_ERR(rb_hammer))) {
 		pr_cont("FAILED\n");
-		ret = -1;
+		ret = PTR_ERR(rb_hammer);
 		goto out_free;
 	}
 

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

queue-4.4/ring-buffer-fix-return-value-check-in-test_ringbuffer.patch