From: Yury Norov <yury.norov@gmail.com>
Date: Fri, 12 Jul 2019 03:53:33 +0000 (-0700)
Subject: mm/slub.c: avoid double string traverse in kmem_cache_flags()
X-Git-Tag: tags/kvm-5.3-2~35^2~119
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=9cf3a8d847bd08977dc168ed243ffbef3c456d88;p=users%2Fdwmw2%2Flinux.git

mm/slub.c: avoid double string traverse in kmem_cache_flags()

If ',' is not found, kmem_cache_flags() calls strlen() to find the end of
line.  We can do it in a single pass using strchrnul().

Link: http://lkml.kernel.org/r/20190501053111.7950-1-ynorov@marvell.com
Signed-off-by: Yury Norov <ynorov@marvell.com>
Acked-by: Aaron Tomlin <atomlin@redhat.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/mm/slub.c b/mm/slub.c
index cd04dbd2b5d05..1802c87799ffc 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1313,9 +1313,7 @@ slab_flags_t kmem_cache_flags(unsigned int object_size,
 		char *end, *glob;
 		size_t cmplen;
 
-		end = strchr(iter, ',');
-		if (!end)
-			end = iter + strlen(iter);
+		end = strchrnul(iter, ',');
 
 		glob = strnchr(iter, end - iter, '*');
 		if (glob)