+ kfifo-fix-kfifo_out_locked-race-bug.patch added to -mm tree

+ kfifo-fix-kfifo_out_locked-race-bug.patch added to -mm tree

[akpm]

The patch titled
     kfifo: fix kfifo_out_locked race bug
has been added to the -mm tree.  Its filename is
     kfifo-fix-kfifo_out_locked-race-bug.patch

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------------------------------------------------------
Subject: kfifo: fix kfifo_out_locked race bug
From: Stefani Seibold <stefani@seibold.net>

Fix a wrong optimization in include/linux/kfifo.h which could cause a race
in kfifo_out_locked.

Signed-off-by: Stefani Seibold <stefani@seibold.net>
Reported-by: Johan Hovold <jhovold@gmail.com>
Cc: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/kfifo.h |    7 -------
 1 file changed, 7 deletions(-)

diff -puN include/linux/kfifo.h~kfifo-fix-kfifo_out_locked-race-bug include/linux/kfifo.h
--- a/include/linux/kfifo.h~kfifo-fix-kfifo_out_locked-race-bug
+++ a/include/linux/kfifo.h
@@ -228,13 +228,6 @@ static inline __must_check unsigned int 
 
 	ret = kfifo_out(fifo, to, n);
 
-	/*
-	 * optimization: if the FIFO is empty, set the indices to 0
-	 * so we don't wrap the next time
-	 */
-	if (kfifo_is_empty(fifo))
-		kfifo_reset(fifo);