[PATCH 4.14 44/62] net: use skb_queue_empty_lockless() in poll() handlers

From: Greg Kroah-Hartman
Date: Fri Nov 08 2019 - 14:19:48 EST


From: Eric Dumazet <edumazet@xxxxxxxxxx>

[ Upstream commit 3ef7cf57c72f32f61e97f8fa401bc39ea1f1a5d4 ]

Many poll() handlers are lockless. Using skb_queue_empty_lockless()
instead of skb_queue_empty() is more appropriate.

Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/isdn/capi/capi.c | 2 +-
net/atm/common.c | 2 +-
net/bluetooth/af_bluetooth.c | 4 ++--
net/caif/caif_socket.c | 2 +-
net/core/datagram.c | 4 ++--
net/ipv4/tcp.c | 2 +-
net/ipv4/udp.c | 2 +-
net/nfc/llcp_sock.c | 4 ++--
net/phonet/socket.c | 4 ++--
net/sctp/socket.c | 4 ++--
net/tipc/socket.c | 4 ++--
net/unix/af_unix.c | 6 +++---
net/vmw_vsock/af_vsock.c | 2 +-
13 files changed, 21 insertions(+), 21 deletions(-)

--- a/drivers/isdn/capi/capi.c
+++ b/drivers/isdn/capi/capi.c
@@ -743,7 +743,7 @@ capi_poll(struct file *file, poll_table

poll_wait(file, &(cdev->recvwait), wait);
mask = POLLOUT | POLLWRNORM;
- if (!skb_queue_empty(&cdev->recvqueue))
+ if (!skb_queue_empty_lockless(&cdev->recvqueue))
mask |= POLLIN | POLLRDNORM;
return mask;
}
--- a/net/atm/common.c
+++ b/net/atm/common.c
@@ -667,7 +667,7 @@ unsigned int vcc_poll(struct file *file,
mask |= POLLHUP;

/* readable? */
- if (!skb_queue_empty(&sk->sk_receive_queue))
+ if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
mask |= POLLIN | POLLRDNORM;

/* writable? */
--- a/net/bluetooth/af_bluetooth.c
+++ b/net/bluetooth/af_bluetooth.c
@@ -460,7 +460,7 @@ unsigned int bt_sock_poll(struct file *f
if (sk->sk_state == BT_LISTEN)
return bt_accept_poll(sk);

- if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
+ if (sk->sk_err || !skb_queue_empty_lockless(&sk->sk_error_queue))
mask |= POLLERR |
(sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0);

@@ -470,7 +470,7 @@ unsigned int bt_sock_poll(struct file *f
if (sk->sk_shutdown == SHUTDOWN_MASK)
mask |= POLLHUP;

- if (!skb_queue_empty(&sk->sk_receive_queue))
+ if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
mask |= POLLIN | POLLRDNORM;

if (sk->sk_state == BT_CLOSED)
--- a/net/caif/caif_socket.c
+++ b/net/caif/caif_socket.c
@@ -953,7 +953,7 @@ static unsigned int caif_poll(struct fil
mask |= POLLRDHUP;

/* readable? */
- if (!skb_queue_empty(&sk->sk_receive_queue) ||
+ if (!skb_queue_empty_lockless(&sk->sk_receive_queue) ||
(sk->sk_shutdown & RCV_SHUTDOWN))
mask |= POLLIN | POLLRDNORM;

--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -844,7 +844,7 @@ unsigned int datagram_poll(struct file *
mask = 0;

/* exceptional events? */
- if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
+ if (sk->sk_err || !skb_queue_empty_lockless(&sk->sk_error_queue))
mask |= POLLERR |
(sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0);

@@ -854,7 +854,7 @@ unsigned int datagram_poll(struct file *
mask |= POLLHUP;

/* readable? */
- if (!skb_queue_empty(&sk->sk_receive_queue))
+ if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
mask |= POLLIN | POLLRDNORM;

/* Connection-based need to check for termination and startup */
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -574,7 +574,7 @@ unsigned int tcp_poll(struct file *file,
}
/* This barrier is coupled with smp_wmb() in tcp_reset() */
smp_rmb();
- if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
+ if (sk->sk_err || !skb_queue_empty_lockless(&sk->sk_error_queue))
mask |= POLLERR;

return mask;
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -2550,7 +2550,7 @@ unsigned int udp_poll(struct file *file,
unsigned int mask = datagram_poll(file, sock, wait);
struct sock *sk = sock->sk;

- if (!skb_queue_empty(&udp_sk(sk)->reader_queue))
+ if (!skb_queue_empty_lockless(&udp_sk(sk)->reader_queue))
mask |= POLLIN | POLLRDNORM;

sock_rps_record_flow(sk);
--- a/net/nfc/llcp_sock.c
+++ b/net/nfc/llcp_sock.c
@@ -567,11 +567,11 @@ static unsigned int llcp_sock_poll(struc
if (sk->sk_state == LLCP_LISTEN)
return llcp_accept_poll(sk);

- if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
+ if (sk->sk_err || !skb_queue_empty_lockless(&sk->sk_error_queue))
mask |= POLLERR |
(sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0);

- if (!skb_queue_empty(&sk->sk_receive_queue))
+ if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
mask |= POLLIN | POLLRDNORM;

if (sk->sk_state == LLCP_CLOSED)
--- a/net/phonet/socket.c
+++ b/net/phonet/socket.c
@@ -352,9 +352,9 @@ static unsigned int pn_socket_poll(struc

if (sk->sk_state == TCP_CLOSE)
return POLLERR;
- if (!skb_queue_empty(&sk->sk_receive_queue))
+ if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
mask |= POLLIN | POLLRDNORM;
- if (!skb_queue_empty(&pn->ctrlreq_queue))
+ if (!skb_queue_empty_lockless(&pn->ctrlreq_queue))
mask |= POLLPRI;
if (!mask && sk->sk_state == TCP_CLOSE_WAIT)
return POLLHUP;
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -7371,7 +7371,7 @@ unsigned int sctp_poll(struct file *file
mask = 0;

/* Is there any exceptional events? */
- if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
+ if (sk->sk_err || !skb_queue_empty_lockless(&sk->sk_error_queue))
mask |= POLLERR |
(sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0);
if (sk->sk_shutdown & RCV_SHUTDOWN)
@@ -7380,7 +7380,7 @@ unsigned int sctp_poll(struct file *file
mask |= POLLHUP;

/* Is it readable? Reconsider this code with TCP-style support. */
- if (!skb_queue_empty(&sk->sk_receive_queue))
+ if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
mask |= POLLIN | POLLRDNORM;

/* The association is either gone or not ready. */
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -714,14 +714,14 @@ static unsigned int tipc_poll(struct fil
/* fall thru' */
case TIPC_LISTEN:
case TIPC_CONNECTING:
- if (!skb_queue_empty(&sk->sk_receive_queue))
+ if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
mask |= (POLLIN | POLLRDNORM);
break;
case TIPC_OPEN:
if (!tsk->cong_link_cnt)
mask |= POLLOUT;
if (tipc_sk_type_connectionless(sk) &&
- (!skb_queue_empty(&sk->sk_receive_queue)))
+ (!skb_queue_empty_lockless(&sk->sk_receive_queue)))
mask |= (POLLIN | POLLRDNORM);
break;
case TIPC_DISCONNECTING:
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -2665,7 +2665,7 @@ static unsigned int unix_poll(struct fil
mask |= POLLRDHUP | POLLIN | POLLRDNORM;

/* readable? */
- if (!skb_queue_empty(&sk->sk_receive_queue))
+ if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
mask |= POLLIN | POLLRDNORM;

/* Connection-based need to check for termination and startup */
@@ -2693,7 +2693,7 @@ static unsigned int unix_dgram_poll(stru
mask = 0;

/* exceptional events? */
- if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
+ if (sk->sk_err || !skb_queue_empty_lockless(&sk->sk_error_queue))
mask |= POLLERR |
(sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0);

@@ -2703,7 +2703,7 @@ static unsigned int unix_dgram_poll(stru
mask |= POLLHUP;

/* readable? */
- if (!skb_queue_empty(&sk->sk_receive_queue))
+ if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
mask |= POLLIN | POLLRDNORM;

/* Connection-based need to check for termination and startup */
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -880,7 +880,7 @@ static unsigned int vsock_poll(struct fi
* the queue and write as long as the socket isn't shutdown for
* sending.
*/
- if (!skb_queue_empty(&sk->sk_receive_queue) ||
+ if (!skb_queue_empty_lockless(&sk->sk_receive_queue) ||
(sk->sk_shutdown & RCV_SHUTDOWN)) {
mask |= POLLIN | POLLRDNORM;
}