From: Harald Freudenberger freude@linux.ibm.com
commit 70fac8088cfad9f3b379c9082832b4d7532c16c2 upstream.
Tests with kvm and a kmemdebug kernel showed, that on hot unplug the zcard and zqueue structs for the unplugged card or queue are not properly freed because of a mismatch with get/put for the embedded kref counter.
This fix now adjusts the handling of the kref counters. With init the kref counter starts with 1. This initial value needs to drop to zero with the unregister of the card or queue to trigger the release and free the object.
Fixes: 29c2680fd2bf ("s390/ap: fix ap devices reference counting") Reported-by: Marc Hartmayer mhartmay@linux.ibm.com Signed-off-by: Harald Freudenberger freude@linux.ibm.com Cc: stable@vger.kernel.org Reviewed-by: Julian Wiedmann jwi@linux.ibm.com Signed-off-by: Heiko Carstens hca@linux.ibm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/s390/crypto/zcrypt_card.c | 1 + drivers/s390/crypto/zcrypt_queue.c | 1 + 2 files changed, 2 insertions(+)
--- a/drivers/s390/crypto/zcrypt_card.c +++ b/drivers/s390/crypto/zcrypt_card.c @@ -192,5 +192,6 @@ void zcrypt_card_unregister(struct zcryp spin_unlock(&zcrypt_list_lock); sysfs_remove_group(&zc->card->ap_dev.device.kobj, &zcrypt_card_attr_group); + zcrypt_card_put(zc); } EXPORT_SYMBOL(zcrypt_card_unregister); --- a/drivers/s390/crypto/zcrypt_queue.c +++ b/drivers/s390/crypto/zcrypt_queue.c @@ -223,5 +223,6 @@ void zcrypt_queue_unregister(struct zcry sysfs_remove_group(&zq->queue->ap_dev.device.kobj, &zcrypt_queue_attr_group); zcrypt_card_put(zc); + zcrypt_queue_put(zq); } EXPORT_SYMBOL(zcrypt_queue_unregister);