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Commit 4e56296d authored by Ralph Wuerthner's avatar Ralph Wuerthner Committed by Martin Schwidefsky
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[S390] zcrypt device registration/unregistration race. 



Fix a race condition during AP device registration and unregistration.

Signed-off-by: default avatarRalph Wuerthner <rwuerthn@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent f1ee3281

drivers/s390/crypto/ap_bus.c

+12 −11
Original line number Diff line number Diff line
@@ -449,8 +449,6 @@ static int ap_device_probe(struct device *dev) 


	ap_dev->drv = ap_drv;

	rc = ap_drv->probe ? ap_drv->probe(ap_dev) : -ENODEV;

	if (rc)

		ap_dev->unregistered = 1;

	return rc;

}
@@ -487,14 +485,7 @@ static int ap_device_remove(struct device *dev) 
	struct ap_device *ap_dev = to_ap_dev(dev);

	struct ap_driver *ap_drv = ap_dev->drv;



	spin_lock_bh(&ap_dev->lock);

	__ap_flush_queue(ap_dev);

	/**

	 * set ->unregistered to 1 while holding the lock. This prevents

	 * new messages to be put on the queue from now on.

	 */

	ap_dev->unregistered = 1;

	spin_unlock_bh(&ap_dev->lock);

	ap_flush_queue(ap_dev);

	if (ap_drv->remove)

		ap_drv->remove(ap_dev);

	return 0;
@@ -763,6 +754,7 @@ static void ap_scan_bus(void *data) 
			break;

		ap_dev->qid = qid;

		ap_dev->queue_depth = queue_depth;

		ap_dev->unregistered = 1;

		spin_lock_init(&ap_dev->lock);

		INIT_LIST_HEAD(&ap_dev->pendingq);

		INIT_LIST_HEAD(&ap_dev->requestq);
@@ -784,7 +776,12 @@ static void ap_scan_bus(void *data) 
		/* Add device attributes. */

		rc = sysfs_create_group(&ap_dev->device.kobj,

					&ap_dev_attr_group);

		if (rc)

		if (!rc) {

			spin_lock_bh(&ap_dev->lock);

			ap_dev->unregistered = 0;

			spin_unlock_bh(&ap_dev->lock);

		}

		else

			device_unregister(&ap_dev->device);

	}

}
@@ -970,6 +967,8 @@ void ap_queue_message(struct ap_device *ap_dev, struct ap_message *ap_msg) 
			rc = __ap_queue_message(ap_dev, ap_msg);

		if (!rc)

			wake_up(&ap_poll_wait);

		if (rc == -ENODEV)

			ap_dev->unregistered = 1;

	} else {

		ap_dev->drv->receive(ap_dev, ap_msg, ERR_PTR(-ENODEV));

		rc = 0;
@@ -1028,6 +1027,8 @@ static int __ap_poll_all(struct device *dev, void *data) 
	spin_lock(&ap_dev->lock);

	if (!ap_dev->unregistered) {

		rc = ap_poll_queue(to_ap_dev(dev), (unsigned long *) data);

		if (rc)

			ap_dev->unregistered = 1;

	} else

		rc = 0;

	spin_unlock(&ap_dev->lock);