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>
This commit is contained in:
Paul E. McKenney 2009-06-25 12:31:37 -07:00 коммит произвёл Pekka Enberg
Родитель 28d0325ce6
Коммит 7ed9f7e5db
3 изменённых файлов: 5 добавлений и 1 удалений

Просмотреть файл

@ -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);

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@ -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);

Просмотреть файл

@ -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) {