[S390] zcrypt: fix possible race when unloading zcrypt driver modules
Move try_module_get() call into spin protected block to prevent zcrypt
driver module unload while submitting a request to driver.
Signed-off-by: Ralph Wuerthner <rwuerthn@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c
index 9976139..e3625a4 100644
--- a/drivers/s390/crypto/zcrypt_api.c
+++ b/drivers/s390/crypto/zcrypt_api.c
@@ -298,14 +298,14 @@
get_device(&zdev->ap_dev->device);
zdev->request_count++;
__zcrypt_decrease_preference(zdev);
- spin_unlock_bh(&zcrypt_device_lock);
if (try_module_get(zdev->ap_dev->drv->driver.owner)) {
+ spin_unlock_bh(&zcrypt_device_lock);
rc = zdev->ops->rsa_modexpo(zdev, mex);
+ spin_lock_bh(&zcrypt_device_lock);
module_put(zdev->ap_dev->drv->driver.owner);
}
else
rc = -EAGAIN;
- spin_lock_bh(&zcrypt_device_lock);
zdev->request_count--;
__zcrypt_increase_preference(zdev);
put_device(&zdev->ap_dev->device);
@@ -373,14 +373,14 @@
get_device(&zdev->ap_dev->device);
zdev->request_count++;
__zcrypt_decrease_preference(zdev);
- spin_unlock_bh(&zcrypt_device_lock);
if (try_module_get(zdev->ap_dev->drv->driver.owner)) {
+ spin_unlock_bh(&zcrypt_device_lock);
rc = zdev->ops->rsa_modexpo_crt(zdev, crt);
+ spin_lock_bh(&zcrypt_device_lock);
module_put(zdev->ap_dev->drv->driver.owner);
}
else
rc = -EAGAIN;
- spin_lock_bh(&zcrypt_device_lock);
zdev->request_count--;
__zcrypt_increase_preference(zdev);
put_device(&zdev->ap_dev->device);
@@ -408,14 +408,14 @@
get_device(&zdev->ap_dev->device);
zdev->request_count++;
__zcrypt_decrease_preference(zdev);
- spin_unlock_bh(&zcrypt_device_lock);
if (try_module_get(zdev->ap_dev->drv->driver.owner)) {
+ spin_unlock_bh(&zcrypt_device_lock);
rc = zdev->ops->send_cprb(zdev, xcRB);
+ spin_lock_bh(&zcrypt_device_lock);
module_put(zdev->ap_dev->drv->driver.owner);
}
else
rc = -EAGAIN;
- spin_lock_bh(&zcrypt_device_lock);
zdev->request_count--;
__zcrypt_increase_preference(zdev);
put_device(&zdev->ap_dev->device);