summary refs log tree commit diff
path: root/mm
diff options
context:
space:
mode:
authorChristoph Lameter <clameter@sgi.com>2007-07-17 04:03:25 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-17 10:23:01 -0700
commitdfce8648d64c07eade40d456d59cb4bfcbba008c (patch)
tree7141882bd03d9848ec6299a48bc08796a8382062 /mm
parent2e443fd003d76394a8ceb78f079260478aa10710 (diff)
downloadlinux-dfce8648d64c07eade40d456d59cb4bfcbba008c.tar.gz
SLUB: do proper locking during dma slab creation
We modify the kmalloc_cache_dma[] array without proper locking.  Do the proper
locking and undo the dma cache creation if another processor has already
created it.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/slub.c11
1 files changed, 9 insertions, 2 deletions
diff --git a/mm/slub.c b/mm/slub.c
index 2b50b97a0fc3..f93adb915c00 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2301,8 +2301,15 @@ static noinline struct kmem_cache *dma_kmalloc_cache(int index, gfp_t flags)
 	text = kasprintf(flags & ~SLUB_DMA, "kmalloc_dma-%d",
 			(unsigned int)realsize);
 	s = create_kmalloc_cache(x, text, realsize, flags);
-	kmalloc_caches_dma[index] = s;
-	return s;
+	down_write(&slub_lock);
+	if (!kmalloc_caches_dma[index]) {
+		kmalloc_caches_dma[index] = s;
+		up_write(&slub_lock);
+		return s;
+	}
+	up_write(&slub_lock);
+	kmem_cache_destroy(s);
+	return kmalloc_caches_dma[index];
 }
 #endif