From dcf70cefaf99a40cfa25face160f29c1cf3bf84d Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 12 Jun 2019 09:52:28 -0700 Subject: [PATCH] net/packet: constify prb_lookup_block() and __tpacket_v3_has_room() Goal is to be able to use __tpacket_v3_has_room() without holding a lock. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/packet/af_packet.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 273bffd..5ef63d0 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -1082,10 +1082,10 @@ static void *packet_current_rx_frame(struct packet_sock *po, } } -static void *prb_lookup_block(struct packet_sock *po, - struct packet_ring_buffer *rb, - unsigned int idx, - int status) +static void *prb_lookup_block(const struct packet_sock *po, + const struct packet_ring_buffer *rb, + unsigned int idx, + int status) { struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx); @@ -1211,12 +1211,12 @@ static bool __tpacket_has_room(const struct packet_sock *po, int pow_off) return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL); } -static bool __tpacket_v3_has_room(struct packet_sock *po, int pow_off) +static bool __tpacket_v3_has_room(const struct packet_sock *po, int pow_off) { int idx, len; - len = po->rx_ring.prb_bdqc.knum_blocks; - idx = po->rx_ring.prb_bdqc.kactive_blk_num; + len = READ_ONCE(po->rx_ring.prb_bdqc.knum_blocks); + idx = READ_ONCE(po->rx_ring.prb_bdqc.kactive_blk_num); if (pow_off) idx += len >> pow_off; if (idx >= len) -- 2.7.4