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author | David Rientjes <rientjes@google.com> | 2014-09-25 16:05:20 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-09-26 08:10:35 -0700 |
commit | d4a5fca592b9ab52b90bb261a90af3c8f53be011 (patch) | |
tree | ee03eb6ccce084507f013104e2ccf75b0138f0b4 /mm/slab.c | |
parent | 87e6d49a000fa6148bd539f632706b02c3485c5d (diff) | |
download | lwn-d4a5fca592b9ab52b90bb261a90af3c8f53be011.tar.gz lwn-d4a5fca592b9ab52b90bb261a90af3c8f53be011.zip |
mm, slab: initialize object alignment on cache creation
Since commit 4590685546a3 ("mm/sl[aou]b: Common alignment code"), the
"ralign" automatic variable in __kmem_cache_create() may be used as
uninitialized.
The proper alignment defaults to BYTES_PER_WORD and can be overridden by
SLAB_RED_ZONE or the alignment specified by the caller.
This fixes https://bugzilla.kernel.org/show_bug.cgi?id=85031
Signed-off-by: David Rientjes <rientjes@google.com>
Reported-by: Andrei Elovikov <a.elovikov@gmail.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/slab.c')
-rw-r--r-- | mm/slab.c | 11 |
1 files changed, 2 insertions, 9 deletions
diff --git a/mm/slab.c b/mm/slab.c index a467b308c682..b8b619bc84ad 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2124,7 +2124,8 @@ static int __init_refok setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp) int __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags) { - size_t left_over, freelist_size, ralign; + size_t left_over, freelist_size; + size_t ralign = BYTES_PER_WORD; gfp_t gfp; int err; size_t size = cachep->size; @@ -2157,14 +2158,6 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags) size &= ~(BYTES_PER_WORD - 1); } - /* - * Redzoning and user store require word alignment or possibly larger. - * Note this will be overridden by architecture or caller mandated - * alignment if either is greater than BYTES_PER_WORD. - */ - if (flags & SLAB_STORE_USER) - ralign = BYTES_PER_WORD; - if (flags & SLAB_RED_ZONE) { ralign = REDZONE_ALIGN; /* If redzoning, ensure that the second redzone is suitably |