1 files changed, 29 insertions, 17 deletions

diff --git a/net/core/stream.c b/net/core/stream.c
index 06b36c730ce8..7a37e7dd2c43 100644
--- a/net/core/stream.c
+++ b/net/core/stream.c
@@ -23,9 +23,13 @@
 
 /**
  * sk_stream_write_space - stream socket write_space callback.
- * @sk: socket
+ * @sk: pointer to the socket structure
  *
- * FIXME: write proper description
+ * This function is invoked when there's space available in the socket's
+ * send buffer for writing. It first checks if the socket is writable,
+ * clears the SOCK_NOSPACE flag indicating that memory for writing
+ * is now available, wakes up any processes waiting for write operations
+ * and sends asynchronous notifications if needed.
  */
 void sk_stream_write_space(struct sock *sk)
 {
@@ -73,13 +77,13 @@ int sk_stream_wait_connect(struct sock *sk, long *timeo_p)
 		add_wait_queue(sk_sleep(sk), &wait);
 		sk->sk_write_pending++;
 		done = sk_wait_event(sk, timeo_p,
-				     !sk->sk_err &&
-				     !((1 << sk->sk_state) &
+				     !READ_ONCE(sk->sk_err) &&
+				     !((1 << READ_ONCE(sk->sk_state)) &
 				       ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)), &wait);
 		remove_wait_queue(sk_sleep(sk), &wait);
 		sk->sk_write_pending--;
 	} while (!done);
-	return 0;
+	return done < 0 ? done : 0;
 }
 EXPORT_SYMBOL(sk_stream_wait_connect);
 
@@ -87,9 +91,9 @@ EXPORT_SYMBOL(sk_stream_wait_connect);
  * sk_stream_closing - Return 1 if we still have things to send in our buffers.
  * @sk: socket to verify
  */
-static inline int sk_stream_closing(struct sock *sk)
+static int sk_stream_closing(const struct sock *sk)
 {
-	return (1 << sk->sk_state) &
+	return (1 << READ_ONCE(sk->sk_state)) &
 	       (TCPF_FIN_WAIT1 | TCPF_CLOSING | TCPF_LAST_ACK);
 }
 
@@ -117,13 +121,13 @@ EXPORT_SYMBOL(sk_stream_wait_close);
  */
 int sk_stream_wait_memory(struct sock *sk, long *timeo_p)
 {
-	int err = 0;
+	int ret, err = 0;
 	long vm_wait = 0;
 	long current_timeo = *timeo_p;
 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
 
 	if (sk_stream_memory_free(sk))
-		current_timeo = vm_wait = (prandom_u32() % (HZ / 5)) + 2;
+		current_timeo = vm_wait = get_random_u32_below(HZ / 5) + 2;
 
 	add_wait_queue(sk_sleep(sk), &wait);
 
@@ -142,11 +146,13 @@ int sk_stream_wait_memory(struct sock *sk, long *timeo_p)
 
 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
 		sk->sk_write_pending++;
-		sk_wait_event(sk, &current_timeo, sk->sk_err ||
-						  (sk->sk_shutdown & SEND_SHUTDOWN) ||
-						  (sk_stream_memory_free(sk) &&
-						  !vm_wait), &wait);
+		ret = sk_wait_event(sk, &current_timeo, READ_ONCE(sk->sk_err) ||
+				    (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN) ||
+				    (sk_stream_memory_free(sk) && !vm_wait),
+				    &wait);
 		sk->sk_write_pending--;
+		if (ret < 0)
+			goto do_error;
 
 		if (vm_wait) {
 			vm_wait -= current_timeo;
@@ -159,7 +165,8 @@ int sk_stream_wait_memory(struct sock *sk, long *timeo_p)
 		*timeo_p = current_timeo;
 	}
 out:
-	remove_wait_queue(sk_sleep(sk), &wait);
+	if (!sock_flag(sk, SOCK_DEAD))
+		remove_wait_queue(sk_sleep(sk), &wait);
 	return err;
 
 do_error:
@@ -195,14 +202,19 @@ void sk_stream_kill_queues(struct sock *sk)
 	/* First the read buffer. */
 	__skb_queue_purge(&sk->sk_receive_queue);
 
+	/* Next, the error queue.
+	 * We need to use queue lock, because other threads might
+	 * add packets to the queue without socket lock being held.
+	 */
+	skb_queue_purge(&sk->sk_error_queue);
+
 	/* Next, the write queue. */
-	WARN_ON(!skb_queue_empty(&sk->sk_write_queue));
+	WARN_ON_ONCE(!skb_queue_empty(&sk->sk_write_queue));
 
 	/* Account for returned memory. */
 	sk_mem_reclaim_final(sk);
 
-	WARN_ON(sk->sk_wmem_queued);
-	WARN_ON(sk->sk_forward_alloc);
+	WARN_ON_ONCE(sk->sk_wmem_queued);
 
 	/* It is _impossible_ for the backlog to contain anything
 	 * when we get here.  All user references to this socket