1 files changed, 36 insertions, 6 deletions

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 18e3a12eb1b2..46efa03d2b11 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -252,6 +252,7 @@
 #include <linux/types.h>
 #include <linux/fcntl.h>
 #include <linux/poll.h>
+#include <linux/inet_diag.h>
 #include <linux/init.h>
 #include <linux/fs.h>
 #include <linux/skbuff.h>
@@ -520,8 +521,10 @@ unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
 
                                 /* Race breaker. If space is freed after
                                  * wspace test but before the flags are set,
-                                 * IO signal will be lost.
+                                 * IO signal will be lost. Memory barrier
+                                 * pairs with the input side.
                                  */
+                                smp_mb__after_atomic();
                                 if (sk_stream_is_writeable(sk))
                                         mask |= POLLOUT | POLLWRNORM;
                         }
@@ -2590,11 +2593,12 @@ EXPORT_SYMBOL(compat_tcp_setsockopt);
 #endif
 
 /* Return information about state of tcp endpoint in API format. */
-void tcp_get_info(const struct sock *sk, struct tcp_info *info)
+void tcp_get_info(struct sock *sk, struct tcp_info *info)
 {
         const struct tcp_sock *tp = tcp_sk(sk);
         const struct inet_connection_sock *icsk = inet_csk(sk);
         u32 now = tcp_time_stamp;
+        u32 rate;
 
         memset(info, 0, sizeof(*info));
 
@@ -2655,10 +2659,16 @@ void tcp_get_info(const struct sock *sk, struct tcp_info *info)
 
         info->tcpi_total_retrans = tp->total_retrans;
 
-        info->tcpi_pacing_rate = sk->sk_pacing_rate != ~0U ?
-                                        sk->sk_pacing_rate : ~0ULL;
-        info->tcpi_max_pacing_rate = sk->sk_max_pacing_rate != ~0U ?
-                                        sk->sk_max_pacing_rate : ~0ULL;
+        rate = READ_ONCE(sk->sk_pacing_rate);
+        info->tcpi_pacing_rate = rate != ~0U ? rate : ~0ULL;
+
+        rate = READ_ONCE(sk->sk_max_pacing_rate);
+        info->tcpi_max_pacing_rate = rate != ~0U ? rate : ~0ULL;
+
+        spin_lock_bh(&sk->sk_lock.slock);
+        info->tcpi_bytes_acked = tp->bytes_acked;
+        info->tcpi_bytes_received = tp->bytes_received;
+        spin_unlock_bh(&sk->sk_lock.slock);
 }
 EXPORT_SYMBOL_GPL(tcp_get_info);
 
@@ -2730,6 +2740,26 @@ static int do_tcp_getsockopt(struct sock *sk, int level,
                         return -EFAULT;
                 return 0;
         }
+        case TCP_CC_INFO: {
+                const struct tcp_congestion_ops *ca_ops;
+                union tcp_cc_info info;
+                size_t sz = 0;
+                int attr;
+
+                if (get_user(len, optlen))
+                        return -EFAULT;
+
+                ca_ops = icsk->icsk_ca_ops;
+                if (ca_ops && ca_ops->get_info)
+                        sz = ca_ops->get_info(sk, ~0U, &attr, &info);
+
+                len = min_t(unsigned int, len, sz);
+                if (put_user(len, optlen))
+                        return -EFAULT;
+                if (copy_to_user(optval, &info, len))
+                        return -EFAULT;
+                return 0;
+        }
         case TCP_QUICKACK:
                 val = !icsk->icsk_ack.pingpong;
                 break;