[S390] zcrypt: Fix possible dead lock in AP bus module.
If a AP device is unconfigured __ap_poll_all() will call device_unregister() in software interrupt context which can cause dead locks. To fix this the device will be only marked as unconfigured and the device_unregister() call will be done later by either ap_scan_bus() or ap_queue_message() in process context. Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Ralph Wuerthner <rwuerthn@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
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@ -757,10 +757,16 @@ static void ap_scan_bus(struct work_struct *unused)
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(void *)(unsigned long)qid,
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(void *)(unsigned long)qid,
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__ap_scan_bus);
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__ap_scan_bus);
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rc = ap_query_queue(qid, &queue_depth, &device_type);
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rc = ap_query_queue(qid, &queue_depth, &device_type);
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if (dev && rc) {
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if (dev) {
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put_device(dev);
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ap_dev = to_ap_dev(dev);
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device_unregister(dev);
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spin_lock_bh(&ap_dev->lock);
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continue;
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if (rc || ap_dev->unregistered) {
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spin_unlock_bh(&ap_dev->lock);
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put_device(dev);
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device_unregister(dev);
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continue;
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} else
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spin_unlock_bh(&ap_dev->lock);
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}
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}
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if (dev) {
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if (dev) {
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put_device(dev);
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put_device(dev);
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@ -994,7 +1000,7 @@ void ap_queue_message(struct ap_device *ap_dev, struct ap_message *ap_msg)
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ap_dev->unregistered = 1;
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ap_dev->unregistered = 1;
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} else {
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} else {
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ap_dev->drv->receive(ap_dev, ap_msg, ERR_PTR(-ENODEV));
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ap_dev->drv->receive(ap_dev, ap_msg, ERR_PTR(-ENODEV));
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rc = 0;
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rc = -ENODEV;
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}
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}
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spin_unlock_bh(&ap_dev->lock);
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spin_unlock_bh(&ap_dev->lock);
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if (rc == -ENODEV)
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if (rc == -ENODEV)
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@ -1044,18 +1050,12 @@ static void ap_poll_timeout(unsigned long unused)
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*/
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*/
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static int __ap_poll_all(struct ap_device *ap_dev, unsigned long *flags)
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static int __ap_poll_all(struct ap_device *ap_dev, unsigned long *flags)
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{
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{
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int rc;
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spin_lock(&ap_dev->lock);
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spin_lock(&ap_dev->lock);
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if (!ap_dev->unregistered) {
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if (!ap_dev->unregistered) {
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rc = ap_poll_queue(ap_dev, flags);
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if (ap_poll_queue(ap_dev, flags))
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if (rc)
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ap_dev->unregistered = 1;
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ap_dev->unregistered = 1;
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} else
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}
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rc = 0;
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spin_unlock(&ap_dev->lock);
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spin_unlock(&ap_dev->lock);
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if (rc)
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device_unregister(&ap_dev->device);
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return 0;
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return 0;
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}
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}
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