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authorEric Dumazet <edumazet@google.com>2019-10-10 20:17:44 -0700
committerDavid S. Miller <davem@davemloft.net>2019-10-13 10:13:08 -0700
commitebb3b78db7bf842270a46fd4fe7cc45c78fa5ed6 (patch)
tree9a0ecbc667473f785c77851f2db6c31f1fa3d2a4 /net
parenttcp: annotate tp->urg_seq lockless reads (diff)
downloadlinux-dev-ebb3b78db7bf842270a46fd4fe7cc45c78fa5ed6.tar.xz
linux-dev-ebb3b78db7bf842270a46fd4fe7cc45c78fa5ed6.zip
tcp: annotate sk->sk_rcvbuf lockless reads
For the sake of tcp_poll(), there are few places where we fetch sk->sk_rcvbuf 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. Note that other transports probably need similar fixes. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/core/filter.c3
-rw-r--r--net/core/skbuff.c2
-rw-r--r--net/core/sock.c5
-rw-r--r--net/ipv4/tcp.c4
-rw-r--r--net/ipv4/tcp_input.c7
5 files changed, 12 insertions, 9 deletions
diff --git a/net/core/filter.c b/net/core/filter.c
index a50c0b6846f2..7deceaeeed7b 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4252,7 +4252,8 @@ BPF_CALL_5(bpf_setsockopt, struct bpf_sock_ops_kern *, bpf_sock,
case SO_RCVBUF:
val = min_t(u32, val, sysctl_rmem_max);
sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
- sk->sk_rcvbuf = max_t(int, val * 2, SOCK_MIN_RCVBUF);
+ WRITE_ONCE(sk->sk_rcvbuf,
+ max_t(int, val * 2, SOCK_MIN_RCVBUF));
break;
case SO_SNDBUF:
val = min_t(u32, val, sysctl_wmem_max);
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 529133611ea2..8c178703467b 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -4415,7 +4415,7 @@ static void skb_set_err_queue(struct sk_buff *skb)
int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb)
{
if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
- (unsigned int)sk->sk_rcvbuf)
+ (unsigned int)READ_ONCE(sk->sk_rcvbuf))
return -ENOMEM;
skb_orphan(skb);
diff --git a/net/core/sock.c b/net/core/sock.c
index 2a053999df11..8c8f61e70141 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -831,7 +831,8 @@ set_rcvbuf:
* returning the value we actually used in getsockopt
* is the most desirable behavior.
*/
- sk->sk_rcvbuf = max_t(int, val * 2, SOCK_MIN_RCVBUF);
+ WRITE_ONCE(sk->sk_rcvbuf,
+ max_t(int, val * 2, SOCK_MIN_RCVBUF));
break;
case SO_RCVBUFFORCE:
@@ -3204,7 +3205,7 @@ void sk_get_meminfo(const struct sock *sk, u32 *mem)
memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
- mem[SK_MEMINFO_RCVBUF] = sk->sk_rcvbuf;
+ mem[SK_MEMINFO_RCVBUF] = READ_ONCE(sk->sk_rcvbuf);
mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
mem[SK_MEMINFO_SNDBUF] = sk->sk_sndbuf;
mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 577a8c6eef9f..bc0481aa6633 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -451,7 +451,7 @@ void tcp_init_sock(struct sock *sk)
icsk->icsk_sync_mss = tcp_sync_mss;
sk->sk_sndbuf = sock_net(sk)->ipv4.sysctl_tcp_wmem[1];
- sk->sk_rcvbuf = sock_net(sk)->ipv4.sysctl_tcp_rmem[1];
+ WRITE_ONCE(sk->sk_rcvbuf, sock_net(sk)->ipv4.sysctl_tcp_rmem[1]);
sk_sockets_allocated_inc(sk);
sk->sk_route_forced_caps = NETIF_F_GSO;
@@ -1711,7 +1711,7 @@ int tcp_set_rcvlowat(struct sock *sk, int val)
val <<= 1;
if (val > sk->sk_rcvbuf) {
- sk->sk_rcvbuf = val;
+ WRITE_ONCE(sk->sk_rcvbuf, val);
tcp_sk(sk)->window_clamp = tcp_win_from_space(sk, val);
}
return 0;
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 16342e043ab3..6995df20710a 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -483,8 +483,9 @@ static void tcp_clamp_window(struct sock *sk)
!(sk->sk_userlocks & SOCK_RCVBUF_LOCK) &&
!tcp_under_memory_pressure(sk) &&
sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)) {
- sk->sk_rcvbuf = min(atomic_read(&sk->sk_rmem_alloc),
- net->ipv4.sysctl_tcp_rmem[2]);
+ WRITE_ONCE(sk->sk_rcvbuf,
+ min(atomic_read(&sk->sk_rmem_alloc),
+ net->ipv4.sysctl_tcp_rmem[2]));
}
if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf)
tp->rcv_ssthresh = min(tp->window_clamp, 2U * tp->advmss);
@@ -648,7 +649,7 @@ void tcp_rcv_space_adjust(struct sock *sk)
rcvbuf = min_t(u64, rcvwin * rcvmem,
sock_net(sk)->ipv4.sysctl_tcp_rmem[2]);
if (rcvbuf > sk->sk_rcvbuf) {
- sk->sk_rcvbuf = rcvbuf;
+ WRITE_ONCE(sk->sk_rcvbuf, rcvbuf);
/* Make the window clamp follow along. */
tp->window_clamp = tcp_win_from_space(sk, rcvbuf);