Bluetooth: Convert RFCOMM spinlocks into mutexes
authorLibor Pechacek <lpechacek@suse.cz>
Tue, 29 Apr 2014 18:38:34 +0000 (20:38 +0200)
committerMarcel Holtmann <marcel@holtmann.org>
Tue, 6 May 2014 02:25:06 +0000 (19:25 -0700)
Enabling CONFIG_DEBUG_ATOMIC_SLEEP has shown that some rfcomm functions
acquiring spinlocks call sleeping locks further in the chain.  Converting
the offending spinlocks into mutexes makes sleeping safe.

Signed-off-by: Libor Pechacek <lpechacek@suse.cz>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
include/net/bluetooth/rfcomm.h
net/bluetooth/rfcomm/core.c
net/bluetooth/rfcomm/tty.c

index 2611cc389d7d65d03cf298061bf3e4ed32c304cd..578b83127af18545e51c26b859dfa6f80100c263 100644 (file)
@@ -173,7 +173,7 @@ struct rfcomm_dlc {
        struct sk_buff_head   tx_queue;
        struct timer_list     timer;
 
-       spinlock_t    lock;
+       struct mutex  lock;
        unsigned long state;
        unsigned long flags;
        atomic_t      refcnt;
@@ -244,8 +244,8 @@ int  rfcomm_dlc_get_modem_status(struct rfcomm_dlc *d, u8 *v24_sig);
 void rfcomm_dlc_accept(struct rfcomm_dlc *d);
 struct rfcomm_dlc *rfcomm_dlc_exists(bdaddr_t *src, bdaddr_t *dst, u8 channel);
 
-#define rfcomm_dlc_lock(d)     spin_lock(&d->lock)
-#define rfcomm_dlc_unlock(d)   spin_unlock(&d->lock)
+#define rfcomm_dlc_lock(d)     mutex_lock(&d->lock)
+#define rfcomm_dlc_unlock(d)   mutex_unlock(&d->lock)
 
 static inline void rfcomm_dlc_hold(struct rfcomm_dlc *d)
 {
index 633cceeb943eefe798bcc4e8d5a4d85af00b4514..05c609b12a1d7007a811f3176ed546e2b6a64d1e 100644 (file)
@@ -307,7 +307,7 @@ struct rfcomm_dlc *rfcomm_dlc_alloc(gfp_t prio)
        setup_timer(&d->timer, rfcomm_dlc_timeout, (unsigned long)d);
 
        skb_queue_head_init(&d->tx_queue);
-       spin_lock_init(&d->lock);
+       mutex_init(&d->lock);
        atomic_set(&d->refcnt, 1);
 
        rfcomm_dlc_clear_state(d);
index 403ec09f480a2a72983b0b1b9db0222fd6e86742..8e385a0ae60e0bd6e4b1ed7615905a7170c4a8bc 100644 (file)
@@ -70,7 +70,7 @@ struct rfcomm_dev {
 };
 
 static LIST_HEAD(rfcomm_dev_list);
-static DEFINE_SPINLOCK(rfcomm_dev_lock);
+static DEFINE_MUTEX(rfcomm_dev_lock);
 
 static void rfcomm_dev_data_ready(struct rfcomm_dlc *dlc, struct sk_buff *skb);
 static void rfcomm_dev_state_change(struct rfcomm_dlc *dlc, int err);
@@ -96,9 +96,9 @@ static void rfcomm_dev_destruct(struct tty_port *port)
        if (dev->tty_dev)
                tty_unregister_device(rfcomm_tty_driver, dev->id);
 
-       spin_lock(&rfcomm_dev_lock);
+       mutex_lock(&rfcomm_dev_lock);
        list_del(&dev->list);
-       spin_unlock(&rfcomm_dev_lock);
+       mutex_unlock(&rfcomm_dev_lock);
 
        kfree(dev);
 
@@ -161,14 +161,14 @@ static struct rfcomm_dev *rfcomm_dev_get(int id)
 {
        struct rfcomm_dev *dev;
 
-       spin_lock(&rfcomm_dev_lock);
+       mutex_lock(&rfcomm_dev_lock);
 
        dev = __rfcomm_dev_lookup(id);
 
        if (dev && !tty_port_get(&dev->port))
                dev = NULL;
 
-       spin_unlock(&rfcomm_dev_lock);
+       mutex_unlock(&rfcomm_dev_lock);
 
        return dev;
 }
@@ -224,7 +224,7 @@ static struct rfcomm_dev *__rfcomm_dev_add(struct rfcomm_dev_req *req,
        if (!dev)
                return ERR_PTR(-ENOMEM);
 
-       spin_lock(&rfcomm_dev_lock);
+       mutex_lock(&rfcomm_dev_lock);
 
        if (req->dev_id < 0) {
                dev->id = 0;
@@ -305,11 +305,11 @@ static struct rfcomm_dev *__rfcomm_dev_add(struct rfcomm_dev_req *req,
           holds reference to this module. */
        __module_get(THIS_MODULE);
 
-       spin_unlock(&rfcomm_dev_lock);
+       mutex_unlock(&rfcomm_dev_lock);
        return dev;
 
 out:
-       spin_unlock(&rfcomm_dev_lock);
+       mutex_unlock(&rfcomm_dev_lock);
        kfree(dev);
        return ERR_PTR(err);
 }
@@ -524,7 +524,7 @@ static int rfcomm_get_dev_list(void __user *arg)
 
        di = dl->dev_info;
 
-       spin_lock(&rfcomm_dev_lock);
+       mutex_lock(&rfcomm_dev_lock);
 
        list_for_each_entry(dev, &rfcomm_dev_list, list) {
                if (!tty_port_get(&dev->port))
@@ -540,7 +540,7 @@ static int rfcomm_get_dev_list(void __user *arg)
                        break;
        }
 
-       spin_unlock(&rfcomm_dev_lock);
+       mutex_unlock(&rfcomm_dev_lock);
 
        dl->dev_num = n;
        size = sizeof(*dl) + n * sizeof(*di);