2.6.27-stable review patch. If anyone has any objections, please let us know. ------------------ From: Paul E. McKenney 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 Reported-by: Jesper Dangaard Brouer Signed-off-by: Paul E. McKenney Signed-off-by: Pekka Enberg Signed-off-by: Greg Kroah-Hartman --- mm/slab.c | 2 +- mm/slob.c | 2 ++ mm/slub.c | 2 ++ 3 files changed, 5 insertions(+), 1 deletion(-) --- a/mm/slab.c +++ b/mm/slab.c @@ -2580,7 +2580,7 @@ void kmem_cache_destroy(struct kmem_cach } if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) - synchronize_rcu(); + rcu_barrier(); __kmem_cache_destroy(cachep); mutex_unlock(&cache_chain_mutex); --- 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); --- a/mm/slub.c +++ b/mm/slub.c @@ -2447,6 +2447,8 @@ static inline int kmem_cache_close(struc */ 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) { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/