afs: Use kfree_rcu() instead of casting kfree() to rcu_callback_t

afs_put_addrlist() casts kfree() to rcu_callback_t. Apart from being wrong in theory, this might also blow up when people start enforcing function types via compiler instrumentation, and it means the rcu_head has to be first in struct afs_addr_list. Use kfree_rcu() instead, it's simpler and more correct. Signed-off-by: Jann Horn <[email protected]> Signed-off-by: David Howells <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
niw · Mar 13, 2020 · ddd2b85 · ddd2b85
1 parent 0d81a3f
commit ddd2b85
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Showing 2 changed files with 2 additions and 2 deletions.
diff --git a/fs/afs/addr_list.c b/fs/afs/addr_list.c
@@ -19,7 +19,7 @@
 void afs_put_addrlist(struct afs_addr_list *alist)
 {
 	if (alist && refcount_dec_and_test(&alist->usage))
-		call_rcu(&alist->rcu, (rcu_callback_t)kfree);
+		kfree_rcu(alist, rcu);
 }
 
 /*

diff --git a/fs/afs/internal.h b/fs/afs/internal.h
@@ -81,7 +81,7 @@ enum afs_call_state {
  * List of server addresses.
  */
 struct afs_addr_list {
-	struct rcu_head		rcu;		/* Must be first */
+	struct rcu_head		rcu;
 	refcount_t		usage;
 	u32			version;	/* Version */
 	unsigned char		max_addrs;