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authorEric Dumazet <edumazet@google.com>2019-06-12 09:52:29 -0700
committerDavid S. Miller <davem@davemloft.net>2019-06-14 18:52:14 -0700
commit0338a14523e3864524dafb6a66c7b82e94201317 (patch)
tree7fd96784350d56925a0151eb680baa94b8107d08 /net/packet
parentdcf70cefaf99a40cfa25face160f29c1cf3bf84d (diff)
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net/packet: constify __packet_rcv_has_room()
Goal is use the helper without lock being held. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/packet')
-rw-r--r--net/packet/af_packet.c13
1 files changed, 8 insertions, 5 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 5ef63d0c3ad0..a0564855ed9d 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -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;