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| author | Ralph Wuerthner <rwuerthn@de.ibm.com> | 2007-03-26 20:42:42 +0200 |
|---|---|---|
| committer | Heiko Carstens <heiko.carstens@de.ibm.com> | 2007-03-26 20:43:47 +0200 |
| commit | c6a48264739e3486f66e5b21a543c9573b713621 (patch) | |
| tree | a25c70053be8fa8e3a97f7b0bf377f37fa98e31f /drivers/s390/crypto/ap_bus.c | |
| parent | 25c61a1fe8c97d1352a2dc0eda25128b3be0db27 (diff) | |
| download | linux-c6a48264739e3486f66e5b21a543c9573b713621.tar.gz linux-c6a48264739e3486f66e5b21a543c9573b713621.tar.bz2 linux-c6a48264739e3486f66e5b21a543c9573b713621.zip | |
[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>
Diffstat (limited to 'drivers/s390/crypto/ap_bus.c')
| -rw-r--r-- | drivers/s390/crypto/ap_bus.c | 26 |
1 files changed, 13 insertions, 13 deletions
diff --git a/drivers/s390/crypto/ap_bus.c b/drivers/s390/crypto/ap_bus.c index 181b51772b1b..a817dade37c0 100644 --- a/drivers/s390/crypto/ap_bus.c +++ b/drivers/s390/crypto/ap_bus.c @@ -757,10 +757,16 @@ static void ap_scan_bus(struct work_struct *unused) (void *)(unsigned long)qid, __ap_scan_bus); rc = ap_query_queue(qid, &queue_depth, &device_type); - if (dev && rc) { - put_device(dev); - device_unregister(dev); - continue; + if (dev) { + ap_dev = to_ap_dev(dev); + spin_lock_bh(&ap_dev->lock); + if (rc || ap_dev->unregistered) { + spin_unlock_bh(&ap_dev->lock); + put_device(dev); + device_unregister(dev); + continue; + } else + spin_unlock_bh(&ap_dev->lock); } if (dev) { put_device(dev); @@ -994,7 +1000,7 @@ void ap_queue_message(struct ap_device *ap_dev, struct ap_message *ap_msg) ap_dev->unregistered = 1; } else { ap_dev->drv->receive(ap_dev, ap_msg, ERR_PTR(-ENODEV)); - rc = 0; + rc = -ENODEV; } spin_unlock_bh(&ap_dev->lock); if (rc == -ENODEV) @@ -1044,18 +1050,12 @@ static void ap_poll_timeout(unsigned long unused) */ static int __ap_poll_all(struct ap_device *ap_dev, unsigned long *flags) { - int rc; - spin_lock(&ap_dev->lock); if (!ap_dev->unregistered) { - rc = ap_poll_queue(ap_dev, flags); - if (rc) + if (ap_poll_queue(ap_dev, flags)) ap_dev->unregistered = 1; - } else - rc = 0; + } spin_unlock(&ap_dev->lock); - if (rc) - device_unregister(&ap_dev->device); return 0; } |