These changes are the raw update to linux-4.4.6-rt14. Kernel sources

are taken from kernel.org, and rt patch from the rt wiki download page.

During the rebasing, the following patch collided:

Force tick interrupt and get rid of softirq magic(I70131fb85).

Collisions have been removed because its logic was found on the
source already.

Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769
Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>

1 files changed, 133 insertions, 56 deletions

diff --git a/kernel/net/ipv4/tcp.c b/kernel/net/ipv4/tcp.c
index bb2ce74f6..036a76ba2 100644
--- a/kernel/net/ipv4/tcp.c
+++ b/kernel/net/ipv4/tcp.c
@@ -279,6 +279,7 @@
 
 #include <asm/uaccess.h>
 #include <asm/ioctls.h>
+#include <asm/unaligned.h>
 #include <net/busy_poll.h>
 
 int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT;
@@ -388,6 +389,7 @@ void tcp_init_sock(struct sock *sk)
 
 	icsk->icsk_rto = TCP_TIMEOUT_INIT;
 	tp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT);
+	tp->rtt_min[0].rtt = ~0U;
 
 	/* So many TCP implementations out there (incorrectly) count the
 	 * initial SYN frame in their delayed-ACK and congestion control
@@ -450,11 +452,14 @@ unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
 	unsigned int mask;
 	struct sock *sk = sock->sk;
 	const struct tcp_sock *tp = tcp_sk(sk);
+	int state;
 
 	sock_rps_record_flow(sk);
 
 	sock_poll_wait(file, sk_sleep(sk), wait);
-	if (sk->sk_state == TCP_LISTEN)
+
+	state = sk_state_load(sk);
+	if (state == TCP_LISTEN)
 		return inet_csk_listen_poll(sk);
 
 	/* Socket is not locked. We are protected from async events
@@ -491,14 +496,14 @@ unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
 	 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
 	 * blocking on fresh not-connected or disconnected socket. --ANK
 	 */
-	if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == TCP_CLOSE)
+	if (sk->sk_shutdown == SHUTDOWN_MASK || state == TCP_CLOSE)
 		mask |= POLLHUP;
 	if (sk->sk_shutdown & RCV_SHUTDOWN)
 		mask |= POLLIN | POLLRDNORM | POLLRDHUP;
 
 	/* Connected or passive Fast Open socket? */
-	if (sk->sk_state != TCP_SYN_SENT &&
-	    (sk->sk_state != TCP_SYN_RECV || tp->fastopen_rsk)) {
+	if (state != TCP_SYN_SENT &&
+	    (state != TCP_SYN_RECV || tp->fastopen_rsk)) {
 		int target = sock_rcvlowat(sk, 0, INT_MAX);
 
 		if (tp->urg_seq == tp->copied_seq &&
@@ -506,9 +511,6 @@ unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
 		    tp->urg_data)
 			target++;
 
-		/* Potential race condition. If read of tp below will
-		 * escape above sk->sk_state, we can be illegally awaken
-		 * in SYN_* states. */
 		if (tp->rcv_nxt - tp->copied_seq >= target)
 			mask |= POLLIN | POLLRDNORM;
 
@@ -516,8 +518,7 @@ unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
 			if (sk_stream_is_writeable(sk)) {
 				mask |= POLLOUT | POLLWRNORM;
 			} else {  /* send SIGIO later */
-				set_bit(SOCK_ASYNC_NOSPACE,
-					&sk->sk_socket->flags);
+				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
 
 				/* Race breaker. If space is freed after
@@ -627,6 +628,8 @@ static void skb_entail(struct sock *sk, struct sk_buff *skb)
 	sk_mem_charge(sk, skb->truesize);
 	if (tp->nonagle & TCP_NAGLE_PUSH)
 		tp->nonagle &= ~TCP_NAGLE_PUSH;
+
+	tcp_slow_start_after_idle_check(sk);
 }
 
 static inline void tcp_mark_urg(struct tcp_sock *tp, int flags)
@@ -695,8 +698,9 @@ static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
 	struct tcp_splice_state *tss = rd_desc->arg.data;
 	int ret;
 
-	ret = skb_splice_bits(skb, offset, tss->pipe, min(rd_desc->count, len),
-			      tss->flags);
+	ret = skb_splice_bits(skb, skb->sk, offset, tss->pipe,
+			      min(rd_desc->count, len), tss->flags,
+			      skb_socket_splice);
 	if (ret > 0)
 		rd_desc->count -= ret;
 	return ret;
@@ -779,7 +783,7 @@ ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos,
 				ret = -EAGAIN;
 				break;
 			}
-			sk_wait_data(sk, &timeo);
+			sk_wait_data(sk, &timeo, NULL);
 			if (signal_pending(current)) {
 				ret = sock_intr_errno(timeo);
 				break;
@@ -809,16 +813,28 @@ ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos,
 }
 EXPORT_SYMBOL(tcp_splice_read);
 
-struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp)
+struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
+				    bool force_schedule)
 {
 	struct sk_buff *skb;
 
 	/* The TCP header must be at least 32-bit aligned.  */
 	size = ALIGN(size, 4);
 
+	if (unlikely(tcp_under_memory_pressure(sk)))
+		sk_mem_reclaim_partial(sk);
+
 	skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp);
-	if (skb) {
-		if (sk_wmem_schedule(sk, skb->truesize)) {
+	if (likely(skb)) {
+		bool mem_scheduled;
+
+		if (force_schedule) {
+			mem_scheduled = true;
+			sk_forced_mem_schedule(sk, skb->truesize);
+		} else {
+			mem_scheduled = sk_wmem_schedule(sk, skb->truesize);
+		}
+		if (likely(mem_scheduled)) {
 			skb_reserve(skb, sk->sk_prot->max_header);
 			/*
 			 * Make sure that we have exactly size bytes
@@ -885,11 +901,12 @@ static ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset,
 	 */
 	if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) &&
 	    !tcp_passive_fastopen(sk)) {
-		if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
+		err = sk_stream_wait_connect(sk, &timeo);
+		if (err != 0)
 			goto out_err;
 	}
 
-	clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
+	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 
 	mss_now = tcp_send_mss(sk, &size_goal, flags);
 	copied = 0;
@@ -908,7 +925,8 @@ new_segment:
 			if (!sk_stream_memory_free(sk))
 				goto wait_for_sndbuf;
 
-			skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation);
+			skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation,
+						  skb_queue_empty(&sk->sk_write_queue));
 			if (!skb)
 				goto wait_for_memory;
 
@@ -921,7 +939,7 @@ new_segment:
 
 		i = skb_shinfo(skb)->nr_frags;
 		can_coalesce = skb_can_coalesce(skb, i, page, offset);
-		if (!can_coalesce && i >= MAX_SKB_FRAGS) {
+		if (!can_coalesce && i >= sysctl_max_skb_frags) {
 			tcp_mark_push(tp, skb);
 			goto new_segment;
 		}
@@ -951,7 +969,8 @@ new_segment:
 
 		copied += copy;
 		offset += copy;
-		if (!(size -= copy)) {
+		size -= copy;
+		if (!size) {
 			tcp_tx_timestamp(sk, skb);
 			goto out;
 		}
@@ -972,7 +991,8 @@ wait_for_memory:
 		tcp_push(sk, flags & ~MSG_MORE, mss_now,
 			 TCP_NAGLE_PUSH, size_goal);
 
-		if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
+		err = sk_stream_wait_memory(sk, &timeo);
+		if (err != 0)
 			goto do_error;
 
 		mss_now = tcp_send_mss(sk, &size_goal, flags);
@@ -987,6 +1007,9 @@ do_error:
 	if (copied)
 		goto out;
 out_err:
+	/* make sure we wake any epoll edge trigger waiter */
+	if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && err == -EAGAIN))
+		sk->sk_write_space(sk);
 	return sk_stream_error(sk, flags, err);
 }
 
@@ -1092,7 +1115,8 @@ int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
 	 */
 	if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) &&
 	    !tcp_passive_fastopen(sk)) {
-		if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
+		err = sk_stream_wait_connect(sk, &timeo);
+		if (err != 0)
 			goto do_error;
 	}
 
@@ -1110,7 +1134,7 @@ int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
 	}
 
 	/* This should be in poll */
-	clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
+	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 
 	mss_now = tcp_send_mss(sk, &size_goal, flags);
 
@@ -1144,7 +1168,8 @@ new_segment:
 
 			skb = sk_stream_alloc_skb(sk,
 						  select_size(sk, sg),
-						  sk->sk_allocation);
+						  sk->sk_allocation,
+						  skb_queue_empty(&sk->sk_write_queue));
 			if (!skb)
 				goto wait_for_memory;
 
@@ -1187,7 +1212,7 @@ new_segment:
 
 			if (!skb_can_coalesce(skb, i, pfrag->page,
 					      pfrag->offset)) {
-				if (i == MAX_SKB_FRAGS || !sg) {
+				if (i == sysctl_max_skb_frags || !sg) {
 					tcp_mark_push(tp, skb);
 					goto new_segment;
 				}
@@ -1247,7 +1272,8 @@ wait_for_memory:
 			tcp_push(sk, flags & ~MSG_MORE, mss_now,
 				 TCP_NAGLE_PUSH, size_goal);
 
-		if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
+		err = sk_stream_wait_memory(sk, &timeo);
+		if (err != 0)
 			goto do_error;
 
 		mss_now = tcp_send_mss(sk, &size_goal, flags);
@@ -1275,6 +1301,9 @@ do_error:
 		goto out;
 out_err:
 	err = sk_stream_error(sk, flags, err);
+	/* make sure we wake any epoll edge trigger waiter */
+	if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && err == -EAGAIN))
+		sk->sk_write_space(sk);
 	release_sock(sk);
 	return err;
 }
@@ -1554,7 +1583,7 @@ int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
 	int target;		/* Read at least this many bytes */
 	long timeo;
 	struct task_struct *user_recv = NULL;
-	struct sk_buff *skb;
+	struct sk_buff *skb, *last;
 	u32 urg_hole = 0;
 
 	if (unlikely(flags & MSG_ERRQUEUE))
@@ -1614,7 +1643,9 @@ int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
 
 		/* Next get a buffer. */
 
+		last = skb_peek_tail(&sk->sk_receive_queue);
 		skb_queue_walk(&sk->sk_receive_queue, skb) {
+			last = skb;
 			/* Now that we have two receive queues this
 			 * shouldn't happen.
 			 */
@@ -1733,15 +1764,17 @@ int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
 			/* Do not sleep, just process backlog. */
 			release_sock(sk);
 			lock_sock(sk);
-		} else
-			sk_wait_data(sk, &timeo);
+		} else {
+			sk_wait_data(sk, &timeo, last);
+		}
 
 		if (user_recv) {
 			int chunk;
 
 			/* __ Restore normal policy in scheduler __ */
 
-			if ((chunk = len - tp->ucopy.len) != 0) {
+			chunk = len - tp->ucopy.len;
+			if (chunk != 0) {
 				NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk);
 				len -= chunk;
 				copied += chunk;
@@ -1752,7 +1785,8 @@ int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
 do_prequeue:
 				tcp_prequeue_process(sk);
 
-				if ((chunk = len - tp->ucopy.len) != 0) {
+				chunk = len - tp->ucopy.len;
+				if (chunk != 0) {
 					NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
 					len -= chunk;
 					copied += chunk;
@@ -1900,7 +1934,7 @@ void tcp_set_state(struct sock *sk, int state)
 	/* Change state AFTER socket is unhashed to avoid closed
 	 * socket sitting in hash tables.
 	 */
-	sk->sk_state = state;
+	sk_state_store(sk, state);
 
 #ifdef STATE_TRACE
 	SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]);
@@ -2204,7 +2238,8 @@ int tcp_disconnect(struct sock *sk, int flags)
 	sk->sk_shutdown = 0;
 	sock_reset_flag(sk, SOCK_DONE);
 	tp->srtt_us = 0;
-	if ((tp->write_seq += tp->max_window + 2) == 0)
+	tp->write_seq += tp->max_window + 2;
+	if (tp->write_seq == 0)
 		tp->write_seq = 1;
 	icsk->icsk_backoff = 0;
 	tp->snd_cwnd = 2;
@@ -2227,13 +2262,6 @@ int tcp_disconnect(struct sock *sk, int flags)
 }
 EXPORT_SYMBOL(tcp_disconnect);
 
-void tcp_sock_destruct(struct sock *sk)
-{
-	inet_sock_destruct(sk);
-
-	kfree(inet_csk(sk)->icsk_accept_queue.fastopenq);
-}
-
 static inline bool tcp_can_repair_sock(const struct sock *sk)
 {
 	return ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN) &&
@@ -2483,6 +2511,13 @@ static int do_tcp_setsockopt(struct sock *sk, int level,
 			icsk->icsk_syn_retries = val;
 		break;
 
+	case TCP_SAVE_SYN:
+		if (val < 0 || val > 1)
+			err = -EINVAL;
+		else
+			tp->save_syn = val;
+		break;
+
 	case TCP_LINGER2:
 		if (val < 0)
 			tp->linger2 = -1;
@@ -2548,7 +2583,7 @@ static int do_tcp_setsockopt(struct sock *sk, int level,
 		    TCPF_LISTEN))) {
 			tcp_fastopen_init_key_once(true);
 
-			err = fastopen_init_queue(sk, val);
+			fastopen_queue_tune(sk, val);
 		} else {
 			err = -EINVAL;
 		}
@@ -2599,15 +2634,19 @@ EXPORT_SYMBOL(compat_tcp_setsockopt);
 /* Return information about state of tcp endpoint in API format. */
 void tcp_get_info(struct sock *sk, struct tcp_info *info)
 {
-	const struct tcp_sock *tp = tcp_sk(sk);
+	const struct tcp_sock *tp = tcp_sk(sk); /* iff sk_type == SOCK_STREAM */
 	const struct inet_connection_sock *icsk = inet_csk(sk);
 	u32 now = tcp_time_stamp;
 	unsigned int start;
+	u64 rate64;
 	u32 rate;
 
 	memset(info, 0, sizeof(*info));
+	if (sk->sk_type != SOCK_STREAM)
+		return;
+
+	info->tcpi_state = sk_state_load(sk);
 
-	info->tcpi_state = sk->sk_state;
 	info->tcpi_ca_state = icsk->icsk_ca_state;
 	info->tcpi_retransmits = icsk->icsk_retransmits;
 	info->tcpi_probes = icsk->icsk_probes_out;
@@ -2635,7 +2674,7 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info)
 	info->tcpi_snd_mss = tp->mss_cache;
 	info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
 
-	if (sk->sk_state == TCP_LISTEN) {
+	if (info->tcpi_state == TCP_LISTEN) {
 		info->tcpi_unacked = sk->sk_ack_backlog;
 		info->tcpi_sacked = sk->sk_max_ack_backlog;
 	} else {
@@ -2665,16 +2704,20 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info)
 	info->tcpi_total_retrans = tp->total_retrans;
 
 	rate = READ_ONCE(sk->sk_pacing_rate);
-	info->tcpi_pacing_rate = rate != ~0U ? rate : ~0ULL;
+	rate64 = rate != ~0U ? rate : ~0ULL;
+	put_unaligned(rate64, &info->tcpi_pacing_rate);
 
 	rate = READ_ONCE(sk->sk_max_pacing_rate);
-	info->tcpi_max_pacing_rate = rate != ~0U ? rate : ~0ULL;
+	rate64 = rate != ~0U ? rate : ~0ULL;
+	put_unaligned(rate64, &info->tcpi_max_pacing_rate);
 
 	do {
 		start = u64_stats_fetch_begin_irq(&tp->syncp);
-		info->tcpi_bytes_acked = tp->bytes_acked;
-		info->tcpi_bytes_received = tp->bytes_received;
+		put_unaligned(tp->bytes_acked, &info->tcpi_bytes_acked);
+		put_unaligned(tp->bytes_received, &info->tcpi_bytes_received);
 	} while (u64_stats_fetch_retry_irq(&tp->syncp, start));
+	info->tcpi_segs_out = tp->segs_out;
+	info->tcpi_segs_in = tp->segs_in;
 }
 EXPORT_SYMBOL_GPL(tcp_get_info);
 
@@ -2812,10 +2855,7 @@ static int do_tcp_getsockopt(struct sock *sk, int level,
 		break;
 
 	case TCP_FASTOPEN:
-		if (icsk->icsk_accept_queue.fastopenq)
-			val = icsk->icsk_accept_queue.fastopenq->max_qlen;
-		else
-			val = 0;
+		val = icsk->icsk_accept_queue.fastopenq.max_qlen;
 		break;
 
 	case TCP_TIMESTAMP:
@@ -2824,6 +2864,42 @@ static int do_tcp_getsockopt(struct sock *sk, int level,
 	case TCP_NOTSENT_LOWAT:
 		val = tp->notsent_lowat;
 		break;
+	case TCP_SAVE_SYN:
+		val = tp->save_syn;
+		break;
+	case TCP_SAVED_SYN: {
+		if (get_user(len, optlen))
+			return -EFAULT;
+
+		lock_sock(sk);
+		if (tp->saved_syn) {
+			if (len < tp->saved_syn[0]) {
+				if (put_user(tp->saved_syn[0], optlen)) {
+					release_sock(sk);
+					return -EFAULT;
+				}
+				release_sock(sk);
+				return -EINVAL;
+			}
+			len = tp->saved_syn[0];
+			if (put_user(len, optlen)) {
+				release_sock(sk);
+				return -EFAULT;
+			}
+			if (copy_to_user(optval, tp->saved_syn + 1, len)) {
+				release_sock(sk);
+				return -EFAULT;
+			}
+			tcp_saved_syn_free(tp);
+			release_sock(sk);
+		} else {
+			release_sock(sk);
+			len = 0;
+			if (put_user(len, optlen))
+				return -EFAULT;
+		}
+		return 0;
+	}
 	default:
 		return -ENOPROTOOPT;
 	}
@@ -3028,11 +3104,12 @@ __setup("thash_entries=", set_thash_entries);
 
 static void __init tcp_init_mem(void)
 {
-	unsigned long limit = nr_free_buffer_pages() / 8;
+	unsigned long limit = nr_free_buffer_pages() / 16;
+
 	limit = max(limit, 128UL);
-	sysctl_tcp_mem[0] = limit / 4 * 3;
-	sysctl_tcp_mem[1] = limit;
-	sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2;
+	sysctl_tcp_mem[0] = limit / 4 * 3;		/* 4.68 % */
+	sysctl_tcp_mem[1] = limit;			/* 6.25 % */
+	sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2;	/* 9.37 % */
 }
 
 void __init tcp_init(void)