The current code removes the device from the device list in several
places. Do it only in the destructor instead and in the error path of
rfcomm_add_dev() if the device couldn't be initialized.
Signed-off-by: Gianluca Anzolin <gianluca@xxxxxxxxxxxxxx>
---
net/bluetooth/rfcomm/tty.c | 27 ++++++---------------------
1 file changed, 6 insertions(+), 21 deletions(-)
diff --git a/net/bluetooth/rfcomm/tty.c b/net/bluetooth/rfcomm/tty.c
index cd7ff37..9c0e142 100644
--- a/net/bluetooth/rfcomm/tty.c
+++ b/net/bluetooth/rfcomm/tty.c
@@ -76,13 +76,6 @@ static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig);
/* ---- Device functions ---- */
-/*
- * The reason this isn't actually a race, as you no doubt have a little voice
- * screaming at you in your head, is that the refcount should never actually
- * reach zero unless the device has already been taken off the list, in
- * rfcomm_dev_del(). And if that's not true, we'll hit the BUG() in
- * rfcomm_dev_destruct() anyway.
- */
static void rfcomm_dev_destruct(struct tty_port *port)
{
struct rfcomm_dev *dev = container_of(port, struct rfcomm_dev, port);
@@ -90,10 +83,9 @@ static void rfcomm_dev_destruct(struct tty_port *port)
BT_DBG("dev %p dlc %p", dev, dlc);
- /* Refcount should only hit zero when called from rfcomm_dev_del()
- which will have taken us off the list. Everything else are
- refcounting bugs. */
- BUG_ON(!list_empty(&dev->list));
+ spin_lock(&rfcomm_dev_lock);
+ list_del(&dev->list);
+ spin_unlock(&rfcomm_dev_lock);
rfcomm_dlc_lock(dlc);
/* Detach DLC if it's owned by this dev */
@@ -282,7 +274,9 @@ out:
dev->id, NULL);
if (IS_ERR(dev->tty_dev)) {
err = PTR_ERR(dev->tty_dev);
+ spin_lock(&rfcomm_dev_lock);
list_del(&dev->list);
+ spin_unlock(&rfcomm_dev_lock);
goto free;
}
@@ -315,10 +309,6 @@ static void rfcomm_dev_del(struct rfcomm_dev *dev)
}
spin_unlock_irqrestore(&dev->port.lock, flags);
- spin_lock(&rfcomm_dev_lock);
- list_del_init(&dev->list);
- spin_unlock(&rfcomm_dev_lock);
-
tty_port_put(&dev->port);
}
@@ -750,13 +740,8 @@ static void rfcomm_tty_close(struct tty_struct *tty, struct file *filp)
dev->port.tty = NULL;
rfcomm_dlc_unlock(dev->dlc);
- if (test_bit(RFCOMM_TTY_RELEASED, &dev->flags)) {
- spin_lock(&rfcomm_dev_lock);
- list_del_init(&dev->list);
- spin_unlock(&rfcomm_dev_lock);
-
+ if (test_bit(RFCOMM_TTY_RELEASED, &dev->flags))
tty_port_put(&dev->port);
- }
} else
spin_unlock_irqrestore(&dev->port.lock, flags);
--
1.8.3.4
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