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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2009-06-25 12:31:37 -0700
committerPekka Enberg <penberg@cs.helsinki.fi>2009-06-26 12:10:47 +0300
commit7ed9f7e5db58c6e8c2b4b738a75d5dcd8e17aad5 (patch)
treec8ee9b63e1e8d3925b8a08a2b21a331434d183b5
parent28d0325ce6e0a52f53d8af687e6427fee59004d3 (diff)
downloadlinux-7ed9f7e5db58c6e8c2b4b738a75d5dcd8e17aad5.tar.bz2
fix RCU-callback-after-kmem_cache_destroy problem in sl[aou]b
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. Cc: <stable@kernel.org> 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>
-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 e74a16e4ced6..5241b6598ba3 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2547,7 +2547,7 @@ 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 c78742defdc6..9641da3d5e58 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -595,6 +595,8 @@ EXPORT_SYMBOL(kmem_cache_create);
void kmem_cache_destroy(struct kmem_cache *c)
{
kmemleak_free(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 819f056b39c6..a9201d83178b 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2595,6 +2595,8 @@ 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) {