+ char-add-warn_on-in-misc_deregister.patch added to -mm tree

+ char-add-warn_on-in-misc_deregister.patch added to -mm tree

[akpm]

The patch titled
     char: add WARN_ON() in misc_deregister()
has been added to the -mm tree.  Its filename is
     char-add-warn_on-in-misc_deregister.patch

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------------------------------------------------------
Subject: char: add WARN_ON() in misc_deregister()
From: Akinobu Mita <akinobu.mita@gmail.com>

misc_deregister() returns an error only when it attempts to unregister
the device that is not registered. This is the driver's bug.

Most of the drivers don't check the return value of misc_deregister().
(It is not bad thing because most of kernel *_unregister() API always
succeed and do not return value)

So it is better to indicate the error by WARN_ON() in misc_deregister().

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/char/misc.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff -puN drivers/char/misc.c~char-add-warn_on-in-misc_deregister drivers/char/misc.c
--- a/drivers/char/misc.c~char-add-warn_on-in-misc_deregister
+++ a/drivers/char/misc.c
@@ -242,7 +242,7 @@ int misc_deregister(struct miscdevice *m
 {
 	int i = DYNAMIC_MINORS - misc->minor - 1;
 
-	if (list_empty(&misc->list))
+	if (WARN_ON(list_empty(&misc->list)))
 		return -EINVAL;
 
 	mutex_lock(&misc_mtx);
_

Patches currently in -mm which might be from akinobu.mita@gmail.com are

linux-next.patch
kernel-fix-bug_on-checks-for-cpu-notifier-callbacks-direct-call.patch
char-add-warn_on-in-misc_deregister.patch
s390-remove-warn_on-for-misc_deregister-failures.patch