@@ -1224,15 +1224,18 @@ static bool __tpacket_v3_has_room(const struct packet_sock *po, int pow_off)
return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
}
-static int __packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
+static int __packet_rcv_has_room(const struct packet_sock *po,
+ const struct sk_buff *skb)
{
- struct sock *sk = &po->sk;
+ const struct sock *sk = &po->sk;
int ret = ROOM_NONE;
if (po->prot_hook.func != tpacket_rcv) {
- int avail = sk->sk_rcvbuf - atomic_read(&sk->sk_rmem_alloc)
- - (skb ? skb->truesize : 0);
- if (avail > (sk->sk_rcvbuf >> ROOM_POW_OFF))
+ int rcvbuf = READ_ONCE(sk->sk_rcvbuf);
+ int avail = rcvbuf - atomic_read(&sk->sk_rmem_alloc)
+ - (skb ? skb->truesize : 0);
+
+ if (avail > (rcvbuf >> ROOM_POW_OFF))
return ROOM_NORMAL;
else if (avail > 0)
return ROOM_LOW;
Goal is use the helper without lock being held. Signed-off-by: Eric Dumazet <edumazet@google.com> --- net/packet/af_packet.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-)