This is a note to let you know that I've just added the patch titled
slub: do not merge cache if slub_debug contains a never-merge flag
to the 4.9-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:
slub-do-not-merge-cache-if-slub_debug-contains-a-never-merge-flag.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Thu Oct 19 15:04:02 CEST 2017
From: Grygorii Maistrenko <grygoriimkd@xxxxxxxxx>
Date: Wed, 22 Feb 2017 15:40:59 -0800
Subject: slub: do not merge cache if slub_debug contains a never-merge flag
From: Grygorii Maistrenko <grygoriimkd@xxxxxxxxx>
[ Upstream commit c6e28895a4372992961888ffaadc9efc643b5bfe ]
In case CONFIG_SLUB_DEBUG_ON=n, find_mergeable() gets debug features from
commandline but never checks if there are features from the
SLAB_NEVER_MERGE set.
As a result selected by slub_debug caches are always mergeable if they
have been created without a custom constructor set or without one of the
SLAB_* debug features on.
This moves the SLAB_NEVER_MERGE check below the flags update from
commandline to make sure it won't merge the slab cache if one of the debug
features is on.
Link: http://lkml.kernel.org/r/20170101124451.GA4740@lp-laptop-d
Signed-off-by: Grygorii Maistrenko <grygoriimkd@xxxxxxxxx>
Reviewed-by: Pekka Enberg <penberg@xxxxxxxxxx>
Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
Acked-by: Christoph Lameter <cl@xxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
mm/slab_common.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -255,7 +255,7 @@ struct kmem_cache *find_mergeable(size_t
{
struct kmem_cache *s;
- if (slab_nomerge || (flags & SLAB_NEVER_MERGE))
+ if (slab_nomerge)
return NULL;
if (ctor)
@@ -266,6 +266,9 @@ struct kmem_cache *find_mergeable(size_t
size = ALIGN(size, align);
flags = kmem_cache_flags(size, flags, name, NULL);
+ if (flags & SLAB_NEVER_MERGE)
+ return NULL;
+
list_for_each_entry_reverse(s, &slab_caches, list) {
if (slab_unmergeable(s))
continue;
Patches currently in stable-queue which might be from grygoriimkd@xxxxxxxxx are
queue-4.9/slub-do-not-merge-cache-if-slub_debug-contains-a-never-merge-flag.patch