On Mon, 2018-04-02 at 11:01 -0700, Cong Wang wrote:
> After commit 581319c58600 ("net/socket: use per af lockdep classes for sk
> queues")
> sock queue locks now have per-af lockdep classes, including unix socket.
> It is no longer necessary to workaround it.
>
> I noticed this while looking at a syzbot deadlock report, this patch
> itself doesn't fix it (this is why I don't add Reported-by).
>
> Fixes: 581319c58600 ("net/socket: use per af lockdep classes for sk queues")
> Cc: Paolo Abeni <pab...@redhat.com>
> Signed-off-by: Cong Wang <xiyou.wangc...@gmail.com>
> ---
> net/unix/af_unix.c | 10 ----------
> 1 file changed, 10 deletions(-)
>
> diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
> index 2d465bdeccbc..45971e173924 100644
> --- a/net/unix/af_unix.c
> +++ b/net/unix/af_unix.c
> @@ -745,14 +745,6 @@ static struct proto unix_proto = {
> .obj_size = sizeof(struct unix_sock),
> };
>
> -/*
> - * AF_UNIX sockets do not interact with hardware, hence they
> - * dont trigger interrupts - so it's safe for them to have
> - * bh-unsafe locking for their sk_receive_queue.lock. Split off
> - * this special lock-class by reinitializing the spinlock key:
> - */
> -static struct lock_class_key af_unix_sk_receive_queue_lock_key;
> -
> static struct sock *unix_create1(struct net *net, struct socket *sock, int
> kern)
> {
> struct sock *sk = NULL;
> @@ -767,8 +759,6 @@ static struct sock *unix_create1(struct net *net, struct
> socket *sock, int kern)
> goto out;
>
> sock_init_data(sock, sk);
> - lockdep_set_class(&sk->sk_receive_queue.lock,
> - &af_unix_sk_receive_queue_lock_key);
>
> sk->sk_allocation = GFP_KERNEL_ACCOUNT;
> sk->sk_write_space = unix_write_space;
LGTM
Acked-by: Paolo Abeni <pab...@redhat.com>
