On Mon, Mar 20, 2023 at 10:53:23AM +0000, Nuno Gonçalves wrote:
> The remap of fill and completion rings was frowned upon as they
> control the usage of UMEM which does not support concurrent use.
> At the same time this would disallow the remap of this rings
> into another process.
>
> A possible use case is that the user wants to transfer the socket/
> UMEM ownerwhip to another process (via SYS_pidfd_getfd) and so
> would need to also remap this rings.
>
> This will have no impact on current usages and just relaxes the
> remap limitation.
>
> Signed-off-by: Nuno Gonçalves <nunog@xxxxxxxx>
> ---
> net/xdp/xsk.c | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
> index 2ac58b282b5eb..2af4ff64b22bd 100644
> --- a/net/xdp/xsk.c
> +++ b/net/xdp/xsk.c
> @@ -1300,10 +1300,11 @@ static int xsk_mmap(struct file *file, struct socket *sock,
> {
> loff_t offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
> unsigned long size = vma->vm_end - vma->vm_start;
> + int state = READ_ONCE(xs->state);
> struct xdp_sock *xs = xdp_sk(sock->sk);
> struct xsk_queue *q = NULL;
>
> - if (READ_ONCE(xs->state) != XSK_READY)
> + if (!(state == XSK_READY || state == XSK_BOUND))
This if(..) is actually:
if (state != XSK_READY && state != XSK_BOUND)
Thanks
