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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2009-06-25 12:31:37 -0700
committerGreg Kroah-Hartman <gregkh@suse.de>2009-07-30 16:05:58 -0700
commitc6e23180eed05084ec631b2d2de0e94df8b48c74 (patch)
treee3e4ecaad1ca3be4c035ee32ffcc8677fc85f7dd /mm
parent940a9e0f721c8498ebc23888171dac7046660278 (diff)
fix RCU-callback-after-kmem_cache_destroy problem in sl[aou]b
commit 7ed9f7e5db58c6e8c2b4b738a75d5dcd8e17aad5 upstream. Jesper noted that kmem_cache_destroy() invokes synchronize_rcu() rather than rcu_barrier() in the SLAB_DESTROY_BY_RCU case, which could result in RCU callbacks accessing a kmem_cache after it had been destroyed. Acked-by: Matt Mackall <mpm@selenic.com> Reported-by: Jesper Dangaard Brouer <hawk@comx.dk> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'mm')
-rw-r--r--mm/slab.c2
-rw-r--r--mm/slob.c2
-rw-r--r--mm/slub.c2
3 files changed, 5 insertions, 1 deletions
diff --git a/mm/slab.c b/mm/slab.c
index e76eee466886..600e8649629e 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2580,7 +2580,7 @@ void kmem_cache_destroy(struct kmem_cache *cachep)
}
if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU))
- synchronize_rcu();
+ rcu_barrier();
__kmem_cache_destroy(cachep);
mutex_unlock(&cache_chain_mutex);
diff --git a/mm/slob.c b/mm/slob.c
index cb675d126791..ed04252cba58 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -561,6 +561,8 @@ EXPORT_SYMBOL(kmem_cache_create);
void kmem_cache_destroy(struct kmem_cache *c)
{
+ if (c->flags & SLAB_DESTROY_BY_RCU)
+ rcu_barrier();
slob_free(c, sizeof(struct kmem_cache));
}
EXPORT_SYMBOL(kmem_cache_destroy);
diff --git a/mm/slub.c b/mm/slub.c
index 0c83e6afe7b2..f0175b454c74 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2447,6 +2447,8 @@ static inline int kmem_cache_close(struct kmem_cache *s)
*/
void kmem_cache_destroy(struct kmem_cache *s)
{
+ if (s->flags & SLAB_DESTROY_BY_RCU)
+ rcu_barrier();
down_write(&slub_lock);
s->refcount--;
if (!s->refcount) {