Andrey reported a kernel warning for the blocking ops
in between prepare_to_wait() and schedule(), that is
alloc_tx().
Of course, the logic itself is suspicious, other sendmsg()
could handle skb allocation failure very well, not sure
why ATM has to wait for a successful one here. But probably
it is too late to change since the errno and behavior is
visible to user-space. So just leave the logic as it is.
Reported-by: Andrey Konovalov <andreyk...@google.com>
Tested-by: Andrey Konovalov <andreyk...@google.com>
Signed-off-by: Cong Wang <xiyou.wangc...@gmail.com>
---
net/atm/common.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/net/atm/common.c b/net/atm/common.c
index 7ec3bbc..b672231 100644
--- a/net/atm/common.c
+++ b/net/atm/common.c
@@ -572,8 +572,8 @@ int vcc_recvmsg(struct socket *sock, struct msghdr *msg,
size_t size,
int vcc_sendmsg(struct socket *sock, struct msghdr *m, size_t size)
{
+ DEFINE_WAIT_FUNC(wait, woken_wake_function);
struct sock *sk = sock->sk;
- DEFINE_WAIT(wait);
struct atm_vcc *vcc;
struct sk_buff *skb;
int eff, error;
@@ -605,14 +605,14 @@ int vcc_sendmsg(struct socket *sock, struct msghdr *m,
size_t size)
}
eff = (size+3) & ~3; /* align to word boundary */
- prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
+ add_wait_queue(sk_sleep(sk), &wait);
error = 0;
while (!(skb = alloc_tx(vcc, eff))) {
if (m->msg_flags & MSG_DONTWAIT) {
error = -EAGAIN;
break;
}
- schedule();
+ wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
if (signal_pending(current)) {
error = -ERESTARTSYS;
break;
@@ -624,9 +624,8 @@ int vcc_sendmsg(struct socket *sock, struct msghdr *m,
size_t size)
send_sig(SIGPIPE, current, 0);
break;
}
- prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
}
- finish_wait(sk_sleep(sk), &wait);
+ remove_wait_queue(sk_sleep(sk), &wait);
if (error)
goto out;
skb->dev = NULL; /* for paths shared with net_device interfaces */
--
2.5.5
