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Commit 37b07693 authored by Björn Töpel's avatar Björn Töpel Committed by Daniel Borkmann
Browse files

xsk: add missing write- and data-dependency barrier 



Here, we add a missing write-barrier, and use READ_ONCE for the
data-dependency barrier.

Signed-off-by: default avatarBjörn Töpel <bjorn.topel@intel.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent 1c4917da

net/xdp/xsk.c

+9 −5
Original line number Diff line number Diff line
@@ -228,6 +228,8 @@ static int xsk_init_queue(u32 entries, struct xsk_queue **queue, 
	if (!q)

		return -ENOMEM;



	/* Make sure queue is ready before it can be seen by others */

	smp_wmb();

	*queue = q;

	return 0;

}
@@ -532,21 +534,23 @@ static int xsk_mmap(struct file *file, struct socket *sock, 
	unsigned long size = vma->vm_end - vma->vm_start;

	struct xdp_sock *xs = xdp_sk(sock->sk);

	struct xsk_queue *q = NULL;

	struct xdp_umem *umem;

	unsigned long pfn;

	struct page *qpg;



	if (offset == XDP_PGOFF_RX_RING) {

		q = xs->rx;

		q = READ_ONCE(xs->rx);

	} else if (offset == XDP_PGOFF_TX_RING) {

		q = xs->tx;

		q = READ_ONCE(xs->tx);

	} else {

		if (!xs->umem)

		umem = READ_ONCE(xs->umem);

		if (!umem)

			return -EINVAL;



		if (offset == XDP_UMEM_PGOFF_FILL_RING)

			q = xs->umem->fq;

			q = READ_ONCE(umem->fq);

		else if (offset == XDP_UMEM_PGOFF_COMPLETION_RING)

			q = xs->umem->cq;

			q = READ_ONCE(umem->cq);

	}



	if (!q)