[PATCH net-next v1 01/12] vsock: fix EPOLLERR set on non-empty error queue

Stefano Garzarella
Tue, 26 Sep 2023 12:54:51 -0000

On Fri, Sep 22, 2023 at 08:24:17AM +0300, Arseniy Krasnov
wrote:
>If socket's error queue is not empty, EPOLLERR must be set. Otherwise,
>reader of error queue won't detect data in it using EPOLLERR bit.
>Currently for AF_VSOCK this is reproducible only with MSG_ZEROCOPY, as
>this feature is the only user of an error queue of the socket.

So this is not really a fix. I'd use a different title to avoid
confusion on backporting this on stable branches or not.

Maybe just "vsock: set EPOLLERR on non-empty error queue"

The change LGTM.

Stefano

>
>Signed-off-by: Arseniy Krasnov <avkrasnov at salutedevices.com>
>---
> net/vmw_vsock/af_vsock.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
>diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
>index 013b65241b65..d841f4de33b0 100644
>--- a/net/vmw_vsock/af_vsock.c
>+++ b/net/vmw_vsock/af_vsock.c
>@@ -1030,7 +1030,7 @@ static __poll_t vsock_poll(struct file *file, struct
socket *sock,
> 	poll_wait(file, sk_sleep(sk), wait);
> 	mask = 0;
>
>-	if (sk->sk_err)
>+	if (sk->sk_err ||
!skb_queue_empty_lockless(&sk->sk_error_queue))
> 		/* Signify that there has been an error on this socket. */
> 		mask |= EPOLLERR;
>
>--
>2.25.1
>