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authorPeter Hurley <peter@hurleysoftware.com>2015-01-23 12:16:53 -0500
committerJohan Hedberg <johan.hedberg@intel.com>2015-01-23 20:29:42 +0200
commitdfb2fae7cd0a1aa13610b11d54203bcd3893da07 (patch)
tree3aa293285c349233441ae31661c72773992e603e /net/bluetooth/rfcomm/sock.c
parenta1443f5a273713d4bfda360e45aa6e1d14fe7324 (diff)
Bluetooth: Fix nested sleeps
l2cap/rfcomm/sco_sock_accept() are wait loops which may acquire sleeping locks. Since both wait loops and sleeping locks use task_struct.state to sleep and wake, the nested sleeping locks destroy the wait loop state. Use the newly-minted wait_woken() and DEFINE_WAIT_FUNC() for the wait loop. DEFINE_WAIT_FUNC() allows an alternate wake function to be specified; in this case, the predefined scheduler function, woken_wake_function(). This wait construct ensures wakeups will not be missed without requiring the wait loop to set the task state before condition evaluation. How this works: CPU 0 | CPU 1 | | is <condition> set? | no set <condition> | | wake_up_interruptible | woken_wake_function | set WQ_FLAG_WOKEN | try_to_wake_up | | wait_woken | set TASK_INTERRUPTIBLE | WQ_FLAG_WOKEN? yes | set TASK_RUNNING | | - loop - | | is <condition> set? | yes - exit wait loop Fixes "do not call blocking ops when !TASK_RUNNING" warnings in l2cap_sock_accept(), rfcomm_sock_accept() and sco_sock_accept(). Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Diffstat (limited to 'net/bluetooth/rfcomm/sock.c')
-rw-r--r--net/bluetooth/rfcomm/sock.c9
1 files changed, 4 insertions, 5 deletions
diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c
index d8a95755a8a8..3c6d2c8ac1a4 100644
--- a/net/bluetooth/rfcomm/sock.c
+++ b/net/bluetooth/rfcomm/sock.c
@@ -468,7 +468,7 @@ done:
static int rfcomm_sock_accept(struct socket *sock, struct socket *newsock, int flags)
{
- DECLARE_WAITQUEUE(wait, current);
+ DEFINE_WAIT_FUNC(wait, woken_wake_function);
struct sock *sk = sock->sk, *nsk;
long timeo;
int err = 0;
@@ -487,8 +487,6 @@ static int rfcomm_sock_accept(struct socket *sock, struct socket *newsock, int f
/* Wait for an incoming connection. (wake-one). */
add_wait_queue_exclusive(sk_sleep(sk), &wait);
while (1) {
- set_current_state(TASK_INTERRUPTIBLE);
-
if (sk->sk_state != BT_LISTEN) {
err = -EBADFD;
break;
@@ -509,10 +507,11 @@ static int rfcomm_sock_accept(struct socket *sock, struct socket *newsock, int f
}
release_sock(sk);
- timeo = schedule_timeout(timeo);
+
+ timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
+
lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
}
- __set_current_state(TASK_RUNNING);
remove_wait_queue(sk_sleep(sk), &wait);
if (err)

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