@@ -134,6 +134,18 @@ static int unix_table_lock_cmp_fn(const struct lockdep_map *a,
{
return cmp_ptr(a, b);
}
+
+static int unix_state_lock_cmp_fn(const struct lockdep_map *_a,
+ const struct lockdep_map *_b)
+{
+ const struct unix_sock *a, *b;
+
+ a = container_of(_a, struct unix_sock, lock.dep_map);
+ b = container_of(_b, struct unix_sock, lock.dep_map);
+
+ /* unix_state_double_lock(): ascending address order. */
+ return cmp_ptr(a, b);
+}
#endif
static unsigned int unix_unbound_hash(struct sock *sk)
@@ -987,6 +999,7 @@ static struct sock *unix_create1(struct net *net, struct socket *sock, int kern,
u->path.dentry = NULL;
u->path.mnt = NULL;
spin_lock_init(&u->lock);
+ lock_set_cmp_fn(&u->lock, unix_state_lock_cmp_fn, NULL);
mutex_init(&u->iolock); /* single task reading lock */
mutex_init(&u->bindlock); /* single task binding lock */
init_waitqueue_head(&u->peer_wait);
@@ -1335,11 +1348,12 @@ static void unix_state_double_lock(struct sock *sk1, struct sock *sk2)
unix_state_lock(sk1);
return;
}
+
if (sk1 > sk2)
swap(sk1, sk2);
unix_state_lock(sk1);
- unix_state_lock_nested(sk2, U_LOCK_SECOND);
+ unix_state_lock(sk2);
}
static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2)
unix_dgram_connect() and unix_dgram_{send,recv}msg() lock the socket and peer in ascending order of the socket address. Let's define the order as unix_state_lock_cmp_fn() instead of using unix_state_lock_nested(). Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Kent Overstreet <kent.overstreet@linux.dev> --- net/unix/af_unix.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-)