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| author | Kuniyuki Iwashima <kuniyu@amazon.com> | 2024-06-20 22:56:14 +0200 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2024-06-25 11:10:18 +0200 |
| commit | ed99822817cb728eee8786c1c921c69c6be206fe (patch) | |
| tree | defdd84f96cc78516f7b07e5a7766cb62b65ef0a /net/unix | |
| parent | af_unix: Define locking order for unix_table_double_lock(). (diff) | |
| download | linux-ed99822817cb728eee8786c1c921c69c6be206fe.tar.xz linux-ed99822817cb728eee8786c1c921c69c6be206fe.zip | |
af_unix: Define locking order for U_LOCK_SECOND in unix_state_double_lock().
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>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'net/unix')
| -rw-r--r-- | net/unix/af_unix.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 7889d4723959..0657f599bbef 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -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) |