[ 3.8.y.z extended stable ] Patch "s390/bitops: fix find_next_bit_left" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    s390/bitops: fix find_next_bit_left

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.7.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 1bf3fb55fa80bb6c3638d3f3dc2a9827d496469a Mon Sep 17 00:00:00 2001
From: Martin Schwidefsky <schwidefsky at de.ibm.com>
Date: Thu, 25 Jul 2013 10:18:17 +0200
Subject: s390/bitops: fix find_next_bit_left

commit 3b0040a47ad63f7147e9e7d2febb61a3b564bb90 upstream.

The find_next_bit_left function is broken if used with an offset which
is not a multiple of 64. The shift to mask the bits of a 64-bit word
not to search is in the wrong direction, the result can be either a
bit found smaller than the offset or failure to find a set bit.

Signed-off-by: Martin Schwidefsky <schwidefsky at de.ibm.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 arch/s390/include/asm/bitops.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/s390/include/asm/bitops.h b/arch/s390/include/asm/bitops.h
index 1542293..787eb3b 100644
--- a/arch/s390/include/asm/bitops.h
+++ b/arch/s390/include/asm/bitops.h
@@ -698,7 +698,7 @@ static inline int find_next_bit_left(const unsigned long *addr,
 	size -= offset;
 	p = addr + offset / __BITOPS_WORDSIZE;
 	if (bit) {
-		set = __flo_word(0, *p & (~0UL << bit));
+		set = __flo_word(0, *p & (~0UL >> bit));
 		if (set >= size)
 			return size + offset;
 		if (set < __BITOPS_WORDSIZE)
--
1.8.1.2