Commit 164bddac authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

net/packet: convert po->tp_loss to an atomic flag 



tp_loss can be read locklessly.

Convert it to an atomic flag to avoid races.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 74383446

net/packet/af_packet.c

+3 −3
Original line number Diff line number Diff line
@@ -2843,7 +2843,7 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 


		if (unlikely(tp_len < 0)) {

tpacket_error:

			if (po->tp_loss) {

			if (packet_sock_flag(po, PACKET_SOCK_TP_LOSS)) {

				__packet_set_status(po, ph,

						TP_STATUS_AVAILABLE);

				packet_increment_head(&po->tx_ring);
@@ -3886,7 +3886,7 @@ packet_setsockopt(struct socket *sock, int level, int optname, sockptr_t optval, 
		if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {

			ret = -EBUSY;

		} else {

			po->tp_loss = !!val;

			packet_sock_flag_set(po, PACKET_SOCK_TP_LOSS, val);

			ret = 0;

		}

		release_sock(sk);
@@ -4095,7 +4095,7 @@ static int packet_getsockopt(struct socket *sock, int level, int optname, 
		val = po->tp_reserve;

		break;

	case PACKET_LOSS:

		val = po->tp_loss;

		val = packet_sock_flag(po, PACKET_SOCK_TP_LOSS);

		break;

	case PACKET_TIMESTAMP:

		val = READ_ONCE(po->tp_tstamp);

net/packet/diag.c

+1 −1
Original line number Diff line number Diff line
@@ -29,7 +29,7 @@ static int pdiag_put_info(const struct packet_sock *po, struct sk_buff *nlskb) 
		pinfo.pdi_flags |= PDI_ORIGDEV;

	if (po->has_vnet_hdr)

		pinfo.pdi_flags |= PDI_VNETHDR;

	if (po->tp_loss)

	if (packet_sock_flag(po, PACKET_SOCK_TP_LOSS))

		pinfo.pdi_flags |= PDI_LOSS;



	return nla_put(nlskb, PACKET_DIAG_INFO, sizeof(pinfo), &pinfo);

net/packet/internal.h

+2 −2
Original line number Diff line number Diff line
@@ -118,8 +118,7 @@ struct packet_sock { 
	struct mutex		pg_vec_lock;

	unsigned long		flags;

	unsigned int		running;	/* bind_lock must be held */

	unsigned int		has_vnet_hdr:1, /* writer must hold sock lock */

				tp_loss:1;

	unsigned int		has_vnet_hdr:1; /* writer must hold sock lock */

	int			pressure;

	int			ifindex;	/* bound device		*/

	__be16			num;
@@ -146,6 +145,7 @@ enum packet_sock_flags { 
	PACKET_SOCK_ORIGDEV,

	PACKET_SOCK_AUXDATA,

	PACKET_SOCK_TX_HAS_OFF,

	PACKET_SOCK_TP_LOSS,

};



static inline void packet_sock_flag_set(struct packet_sock *po,