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authorBjörn Töpel <bjorn.topel@intel.com>2018-05-22 09:35:01 +0200
committerDaniel Borkmann <daniel@iogearbox.net>2018-05-22 10:25:06 +0200
commit37b076933a8e38e72ffd3c40d3eeb5949f38baf3 (patch)
treed69135d54b4a1036d34377ddc40255b4d22ae49a /net/xdp
parent1c4917da36ed76981cc3c2671b3a44765c02bbc3 (diff)
downloadlinux-stericsson-37b076933a8e38e72ffd3c40d3eeb5949f38baf3.tar.gz
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: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'net/xdp')
-rw-r--r--net/xdp/xsk.c14
1 files changed, 9 insertions, 5 deletions
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index 378dd9287da5..01f010ec0c05 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -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)