mm, slab: move kfence_shutdown_cache() outside slab_mutex

kfence_shutdown_cache() is called under slab_mutex when the cache is
destroyed synchronously, and outside slab_mutex during the delayed
destruction of SLAB_TYPESAFE_BY_RCU caches.

It seems it should always be safe to call it outside of slab_mutex so we
can just move the call to kmem_cache_release(), which is called outside.

Reviewed-by: Jann Horn <jannh@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>

diff --git a/mm/slab_common.c b/mm/slab_common.c
index db61df3b4282e8f9c10df26d28d9854d1f1a68bf..a079b85403342f2b9916960456fa9351334d7c6b 100644 (file)
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -492,6 +492,7 @@ EXPORT_SYMBOL(kmem_buckets_create);
  */
 static void kmem_cache_release(struct kmem_cache *s)
 {
+       kfence_shutdown_cache(s);
        if (__is_defined(SLAB_SUPPORTS_SYSFS) && slab_state >= FULL)
                sysfs_slab_release(s);
        else
@@ -521,10 +522,8 @@ static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work)
 
        rcu_barrier();
 
-       list_for_each_entry_safe(s, s2, &to_destroy, list) {
-               kfence_shutdown_cache(s);
+       list_for_each_entry_safe(s, s2, &to_destroy, list)
                kmem_cache_release(s);
-       }
 }
 
 void slab_kmem_cache_release(struct kmem_cache *s)
@@ -563,9 +562,6 @@ void kmem_cache_destroy(struct kmem_cache *s)
 
        list_del(&s->list);
 
-       if (!err && !rcu_set)
-               kfence_shutdown_cache(s);
-
        mutex_unlock(&slab_mutex);
        cpus_read_unlock();