tcp: Clear sack info on purge (ff8ce518) · Commits · e / devices / android_kernel_fairphone_FP4

This ensures that the sack information is cleared when TCP is in FIN-WAIT1 state. This also tracks whenever tcp queue purge is called which resets all the transmit queue information and ensures there are no outstanding packets. This addresses the following - 16496.596106: <6> Unable to handle kernel paging request at virtual address fffffff2cd81a368 16496.730771: <2> pc : tcp_ack+0x174/0x11e8 16496.734536: <2> lr : tcp_rcv_state_process+0x318/0x1300 16497.183109: <2> Call trace: 16497.183114: <2> tcp_ack+0x174/0x11e8 16497.183115: <2> tcp_rcv_state_process+0x318/0x1300 16497.183117: <2> tcp_v4_do_rcv+0x1a8/0x1f0 16497.183118: <2> tcp_v4_rcv+0xe90/0xec8 16497.183120: <2> ip_protocol_deliver_rcu+0x150/0x298 16497.183121: <2> ip_local_deliver+0x21c/0x2a8 16497.183122: <2> ip_rcv+0x1c4/0x210 16497.183124: <2> __netif_receive_skb_core+0xab0/0xd90 16497.183125: <2> netif_receive_skb_internal+0x12c/0x368 16497.183126: <2> napi_gro_receive+0x1e0/0x290 No outstanding data is expected on a socket after write queue purge is called. CRs-Fixed: 2541019 Change-Id: I586c43931969eae48fe1bf9799ef38267401fdc6 Signed-off-by:

Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>

include/linux/tcp.h

+2 −1

Original line number	Original line	Diff line number	Diff line
	@@ -232,7 +232,8 @@ struct tcp_sock {
	fastopen_connect:1, /* FASTOPEN_CONNECT sockopt */		fastopen_connect:1, /* FASTOPEN_CONNECT sockopt */
	fastopen_no_cookie:1, /* Allow send/recv SYN+data without a cookie */		fastopen_no_cookie:1, /* Allow send/recv SYN+data without a cookie */
	is_sack_reneg:1, /* in recovery from loss with SACK reneg? */		is_sack_reneg:1, /* in recovery from loss with SACK reneg? */
	unused:2;		unused:1,
			wqp_called:1;
	u8 nonagle : 4,/* Disable Nagle algorithm? */		u8 nonagle : 4,/* Disable Nagle algorithm? */
	thin_lto : 1,/* Use linear timeouts for thin streams */		thin_lto : 1,/* Use linear timeouts for thin streams */
	recvmsg_inq : 1,/* Indicate # of bytes in queue upon recvmsg */		recvmsg_inq : 1,/* Indicate # of bytes in queue upon recvmsg */

net/ipv4/tcp.c

+3 −0

Original line number	Original line	Diff line number	Diff line
	@@ -2534,6 +2534,9 @@ void tcp_write_queue_purge(struct sock *sk)
	INIT_LIST_HEAD(&tcp_sk(sk)->tsorted_sent_queue);		INIT_LIST_HEAD(&tcp_sk(sk)->tsorted_sent_queue);
	sk_mem_reclaim(sk);		sk_mem_reclaim(sk);
	tcp_clear_all_retrans_hints(tcp_sk(sk));		tcp_clear_all_retrans_hints(tcp_sk(sk));
			tcp_sk(sk)->highest_sack = NULL;
			tcp_sk(sk)->sacked_out = 0;
			tcp_sk(sk)->wqp_called = 1;
	tcp_sk(sk)->packets_out = 0;		tcp_sk(sk)->packets_out = 0;
	inet_csk(sk)->icsk_backoff = 0;		inet_csk(sk)->icsk_backoff = 0;
	}		}