On Tue, 2016-11-01 at 16:04 -0700, Cong Wang wrote:
> Andrey reported this kernel warning:
> Unlike commit 26cabd31259ba43f68026ce3f62b78094124333f
> ("sched, net: Clean up sk_wait_event() vs. might_sleep()"), the
> sleeping function is called before schedule_timeout(), this is indeed
> a bug. Fix this by moving the wait logic to the new API, it is similar
> to commit ff960a731788a7408b6f66ec4fd772ff18833211
> ("netdev, sched/wait: Fix sleeping inside wait event").
>
> Reported-by: Andrey Konovalov <[email protected]>
> Cc: Andrey Konovalov <[email protected]>
> Cc: Eric Dumazet <[email protected]>
> Cc: Peter Zijlstra <[email protected]>
> Signed-off-by: Cong Wang <[email protected]>
> ---
Excellent.
I guess we could also define sk_wait_event_woken()
and use it instead of sk_wait_event(), and also in
inet_wait_for_connect()
+#define sk_wait_event_woken(__sk, __timeo, __condition, __wait)
\
+ ({ int __rc; \
+ release_sock(__sk); \
+ __rc = __condition; \
+ if (!__rc) { \
+ *(__timeo) = wait_woken(__wait, TASK_INTERRUPTIBLE, \
+ *(__timeo)); \
+ } \
+ lock_sock(__sk); \
+ __rc = __condition; \
+ __rc; \
+ })
sk_wait_data() would need :
@@ -2078,14 +2080,14 @@ void __sk_flush_backlog(struct sock *sk)
*/
int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
{
+ DEFINE_WAIT_FUNC(wait, woken_wake_function);
int rc;
- DEFINE_WAIT(wait);
- prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
+ add_wait_queue(sk_sleep(sk), &wait);
sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
- rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) !=
skb);
+ rc = sk_wait_event_woken(sk, timeo,
skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
- finish_wait(sk_sleep(sk), &wait);
+ remove_wait_queue(sk_sleep(sk), &wait);
return rc;
}
EXPORT_SYMBOL(sk_wait_data);
