From: Eric Dumazet edumazet@google.com
[ Upstream commit 0f31746452e6793ad6271337438af8f4defb8940 ]
There are few places where we fetch tp->write_seq while this field can change from IRQ or other cpu.
We need to add READ_ONCE() annotations, and also make sure write sides use corresponding WRITE_ONCE() to avoid store-tearing.
Signed-off-by: Eric Dumazet edumazet@google.com Signed-off-by: David S. Miller davem@davemloft.net --- include/net/tcp.h | 2 +- net/ipv4/tcp.c | 20 ++++++++++++-------- net/ipv4/tcp_diag.c | 2 +- net/ipv4/tcp_ipv4.c | 21 ++++++++++++--------- net/ipv4/tcp_minisocks.c | 2 +- net/ipv4/tcp_output.c | 4 ++-- net/ipv6/tcp_ipv6.c | 13 +++++++------ 7 files changed, 36 insertions(+), 28 deletions(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h index 4fe3ab47b4803700e50346c0a85bc347046f6730..3f0d654984cf43fbbc5a51ebd4d654803d0e3649 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1880,7 +1880,7 @@ static inline u32 tcp_notsent_lowat(const struct tcp_sock *tp) static inline bool tcp_stream_memory_free(const struct sock *sk) { const struct tcp_sock *tp = tcp_sk(sk); - u32 notsent_bytes = tp->write_seq - tp->snd_nxt; + u32 notsent_bytes = READ_ONCE(tp->write_seq) - tp->snd_nxt;
return notsent_bytes < tcp_notsent_lowat(tp); } diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index f639c7d6083821c8725f5e28312eff3cbfa82e54..370faff782cd363e82014969331df459b8188d94 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -637,7 +637,7 @@ int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg) if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) answ = 0; else - answ = tp->write_seq - tp->snd_una; + answ = READ_ONCE(tp->write_seq) - tp->snd_una; break; case SIOCOUTQNSD: if (sk->sk_state == TCP_LISTEN) @@ -646,7 +646,7 @@ int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg) if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) answ = 0; else - answ = tp->write_seq - tp->snd_nxt; + answ = READ_ONCE(tp->write_seq) - tp->snd_nxt; break; default: return -ENOIOCTLCMD; @@ -1037,7 +1037,7 @@ ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset, sk->sk_wmem_queued += copy; sk_mem_charge(sk, copy); skb->ip_summed = CHECKSUM_PARTIAL; - tp->write_seq += copy; + WRITE_ONCE(tp->write_seq, tp->write_seq + copy); TCP_SKB_CB(skb)->end_seq += copy; tcp_skb_pcount_set(skb, 0);
@@ -1391,7 +1391,7 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size) if (!copied) TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
- tp->write_seq += copy; + WRITE_ONCE(tp->write_seq, tp->write_seq + copy); TCP_SKB_CB(skb)->end_seq += copy; tcp_skb_pcount_set(skb, 0);
@@ -2556,6 +2556,7 @@ int tcp_disconnect(struct sock *sk, int flags) struct inet_connection_sock *icsk = inet_csk(sk); struct tcp_sock *tp = tcp_sk(sk); int old_state = sk->sk_state; + u32 seq;
if (old_state != TCP_CLOSE) tcp_set_state(sk, TCP_CLOSE); @@ -2593,9 +2594,12 @@ int tcp_disconnect(struct sock *sk, int flags) sock_reset_flag(sk, SOCK_DONE); tp->srtt_us = 0; tp->rcv_rtt_last_tsecr = 0; - tp->write_seq += tp->max_window + 2; - if (tp->write_seq == 0) - tp->write_seq = 1; + + seq = tp->write_seq + tp->max_window + 2; + if (!seq) + seq = 1; + WRITE_ONCE(tp->write_seq, seq); + tp->snd_cwnd = 2; icsk->icsk_probes_out = 0; tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; @@ -2885,7 +2889,7 @@ static int do_tcp_setsockopt(struct sock *sk, int level, if (sk->sk_state != TCP_CLOSE) err = -EPERM; else if (tp->repair_queue == TCP_SEND_QUEUE) - tp->write_seq = val; + WRITE_ONCE(tp->write_seq, val); else if (tp->repair_queue == TCP_RECV_QUEUE) { WRITE_ONCE(tp->rcv_nxt, val); WRITE_ONCE(tp->copied_seq, val); diff --git a/net/ipv4/tcp_diag.c b/net/ipv4/tcp_diag.c index a96b252c742cb58108123a5ccad15511634dcfc5..2a46f9f81ba09278195e4fe310cc06c1b3c772f0 100644 --- a/net/ipv4/tcp_diag.c +++ b/net/ipv4/tcp_diag.c @@ -32,7 +32,7 @@ static void tcp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
r->idiag_rqueue = max_t(int, READ_ONCE(tp->rcv_nxt) - READ_ONCE(tp->copied_seq), 0); - r->idiag_wqueue = tp->write_seq - tp->snd_una; + r->idiag_wqueue = READ_ONCE(tp->write_seq) - tp->snd_una; } if (info) tcp_get_info(sk, info); diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 627b5fb1eac8ecf808ea33d2994198b4551f3fc9..ac6135555e24a9b9244d1cd27e3d5619f8252490 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -169,9 +169,11 @@ int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp) * without appearing to create any others. */ if (likely(!tp->repair)) { - tp->write_seq = tcptw->tw_snd_nxt + 65535 + 2; - if (tp->write_seq == 0) - tp->write_seq = 1; + u32 seq = tcptw->tw_snd_nxt + 65535 + 2; + + if (!seq) + seq = 1; + WRITE_ONCE(tp->write_seq, seq); tp->rx_opt.ts_recent = tcptw->tw_ts_recent; tp->rx_opt.ts_recent_stamp = tcptw->tw_ts_recent_stamp; } @@ -258,7 +260,7 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) tp->rx_opt.ts_recent = 0; tp->rx_opt.ts_recent_stamp = 0; if (likely(!tp->repair)) - tp->write_seq = 0; + WRITE_ONCE(tp->write_seq, 0); }
inet->inet_dport = usin->sin_port; @@ -296,10 +298,11 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
if (likely(!tp->repair)) { if (!tp->write_seq) - tp->write_seq = secure_tcp_seq(inet->inet_saddr, - inet->inet_daddr, - inet->inet_sport, - usin->sin_port); + WRITE_ONCE(tp->write_seq, + secure_tcp_seq(inet->inet_saddr, + inet->inet_daddr, + inet->inet_sport, + usin->sin_port)); tp->tsoffset = secure_tcp_ts_off(sock_net(sk), inet->inet_saddr, inet->inet_daddr); @@ -2345,7 +2348,7 @@ static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i) seq_printf(f, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX " "%08X %5u %8d %lu %d %pK %lu %lu %u %u %d", i, src, srcp, dest, destp, state, - tp->write_seq - tp->snd_una, + READ_ONCE(tp->write_seq) - tp->snd_una, rx_queue, timer_active, jiffies_delta_to_clock_t(timer_expires - jiffies), diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index 0b1a04fa54392fdb3325d45fd1d5e0aaa3170b6c..9436fb9b6a3d384b265b080fc41246987fbb0ea4 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -510,7 +510,7 @@ struct sock *tcp_create_openreq_child(const struct sock *sk, newtp->app_limited = ~0U;
tcp_init_xmit_timers(newsk); - newtp->write_seq = newtp->pushed_seq = treq->snt_isn + 1; + WRITE_ONCE(newtp->write_seq, newtp->pushed_seq = treq->snt_isn + 1);
newtp->rx_opt.saw_tstamp = 0;
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 662aa48173b8197e006127e4d84fb2c1961836a4..9b74041e8dd100a0123f89025cee3bed7c58d30e 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1175,7 +1175,7 @@ static void tcp_queue_skb(struct sock *sk, struct sk_buff *skb) struct tcp_sock *tp = tcp_sk(sk);
/* Advance write_seq and place onto the write_queue. */ - tp->write_seq = TCP_SKB_CB(skb)->end_seq; + WRITE_ONCE(tp->write_seq, TCP_SKB_CB(skb)->end_seq); __skb_header_release(skb); tcp_add_write_queue_tail(sk, skb); sk->sk_wmem_queued += skb->truesize; @@ -3397,7 +3397,7 @@ static void tcp_connect_queue_skb(struct sock *sk, struct sk_buff *skb) __skb_header_release(skb); sk->sk_wmem_queued += skb->truesize; sk_mem_charge(sk, skb->truesize); - tp->write_seq = tcb->end_seq; + WRITE_ONCE(tp->write_seq, tcb->end_seq); tp->packets_out += tcp_skb_pcount(skb); }
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index de9b9c0bf18f721f44d7ee0e4eec74c0b5576947..6e84f2eb08d643c2c79f34e90b05329a3dbabb56 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -206,7 +206,7 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr, !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) { tp->rx_opt.ts_recent = 0; tp->rx_opt.ts_recent_stamp = 0; - tp->write_seq = 0; + WRITE_ONCE(tp->write_seq, 0); }
sk->sk_v6_daddr = usin->sin6_addr; @@ -304,10 +304,11 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
if (likely(!tp->repair)) { if (!tp->write_seq) - tp->write_seq = secure_tcpv6_seq(np->saddr.s6_addr32, - sk->sk_v6_daddr.s6_addr32, - inet->inet_sport, - inet->inet_dport); + WRITE_ONCE(tp->write_seq, + secure_tcpv6_seq(np->saddr.s6_addr32, + sk->sk_v6_daddr.s6_addr32, + inet->inet_sport, + inet->inet_dport)); tp->tsoffset = secure_tcpv6_ts_off(sock_net(sk), np->saddr.s6_addr32, sk->sk_v6_daddr.s6_addr32); @@ -1850,7 +1851,7 @@ static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i) dest->s6_addr32[0], dest->s6_addr32[1], dest->s6_addr32[2], dest->s6_addr32[3], destp, state, - tp->write_seq - tp->snd_una, + READ_ONCE(tp->write_seq) - tp->snd_una, rx_queue, timer_active, jiffies_delta_to_clock_t(timer_expires - jiffies),