This is a note to let you know that I've just added the patch titled
asm-generic: Fix 32 bit __generic_cmpxchg_local
to the 6.6-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:
asm-generic-fix-32-bit-__generic_cmpxchg_local.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 0efcbd3c7bd6b638b2fbadda5d00bd0ac50e7f9f
Author: David McKay <david.mckay@xxxxxxxxxxx>
Date: Thu Jan 4 09:40:10 2024 +0000
asm-generic: Fix 32 bit __generic_cmpxchg_local
[ Upstream commit d93cca2f3109f88c94a32d3322ec8b2854a9c339 ]
Commit 656e9007ef58 ("asm-generic: avoid __generic_cmpxchg_local
warnings") introduced a typo that means the code is incorrect for 32 bit
values. It will work fine for postive numbers, but will fail for
negative numbers on a system where longs are 64 bit.
Fixes: 656e9007ef58 ("asm-generic: avoid __generic_cmpxchg_local warnings")
Signed-off-by: David McKay <david.mckay@xxxxxxxxxxx>
Signed-off-by: Stuart Menefy <stuart.menefy@xxxxxxxxxxx>
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/include/asm-generic/cmpxchg-local.h b/include/asm-generic/cmpxchg-local.h
index 3df9f59a544e..f27d66fdc00a 100644
--- a/include/asm-generic/cmpxchg-local.h
+++ b/include/asm-generic/cmpxchg-local.h
@@ -34,7 +34,7 @@ static inline unsigned long __generic_cmpxchg_local(volatile void *ptr,
*(u16 *)ptr = (new & 0xffffu);
break;
case 4: prev = *(u32 *)ptr;
- if (prev == (old & 0xffffffffffu))
+ if (prev == (old & 0xffffffffu))
*(u32 *)ptr = (new & 0xffffffffu);
break;
case 8: prev = *(u64 *)ptr;
