diff options
| author | Eric Dumazet <edumazet@google.com> | 2023-03-16 01:10:06 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2023-03-17 08:52:05 +0000 |
| commit | b9d83ab8a708f23a4001d60e9d8d0b3be3d9f607 (patch) | |
| tree | 23a6ab230684c1a42dd59e0e146c5f035b6eade0 /net/packet/af_packet.c | |
| parent | dc021e6c24e1edd809e4f109783c48e8a74b2d8c (diff) | |
net/packet: annotate accesses to po->xmit
po->xmit can be set from setsockopt(PACKET_QDISC_BYPASS),
while read locklessly.
Use READ_ONCE()/WRITE_ONCE() to avoid potential load/store
tearing issues.
Fixes: d346a3fae3ff ("packet: introduce PACKET_QDISC_BYPASS socket option")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/packet/af_packet.c')
| -rw-r--r-- | net/packet/af_packet.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index d4e76e2ae153..d25dd9f63cc4 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -307,7 +307,8 @@ static void packet_cached_dev_reset(struct packet_sock *po) static bool packet_use_direct_xmit(const struct packet_sock *po) { - return po->xmit == packet_direct_xmit; + /* Paired with WRITE_ONCE() in packet_setsockopt() */ + return READ_ONCE(po->xmit) == packet_direct_xmit; } static u16 packet_pick_tx_queue(struct sk_buff *skb) @@ -2867,7 +2868,8 @@ tpacket_error: packet_inc_pending(&po->tx_ring); status = TP_STATUS_SEND_REQUEST; - err = po->xmit(skb); + /* Paired with WRITE_ONCE() in packet_setsockopt() */ + err = READ_ONCE(po->xmit)(skb); if (unlikely(err != 0)) { if (err > 0) err = net_xmit_errno(err); @@ -3070,7 +3072,8 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) virtio_net_hdr_set_proto(skb, &vnet_hdr); } - err = po->xmit(skb); + /* Paired with WRITE_ONCE() in packet_setsockopt() */ + err = READ_ONCE(po->xmit)(skb); if (unlikely(err != 0)) { if (err > 0) err = net_xmit_errno(err); @@ -4007,7 +4010,8 @@ packet_setsockopt(struct socket *sock, int level, int optname, sockptr_t optval, if (copy_from_sockptr(&val, optval, sizeof(val))) return -EFAULT; - po->xmit = val ? packet_direct_xmit : dev_queue_xmit; + /* Paired with all lockless reads of po->xmit */ + WRITE_ONCE(po->xmit, val ? packet_direct_xmit : dev_queue_xmit); return 0; } default: |