[PATCH 3.16 390/410] s390/qeth: free netdevice when removing a card

From: Ben Hutchings
Date: Thu Jun 07 2018 - 11:04:14 EST


3.16.57-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Julian Wiedmann <jwi@xxxxxxxxxxxxxxxxxx>

commit 6be687395b3124f002a653c1a50b3260222b3cd7 upstream.

On removal, a qeth card's netdevice is currently not properly freed
because the call chain looks as follows:

qeth_core_remove_device(card)
lx_remove_device(card)
unregister_netdev(card->dev)
card->dev = NULL !!!
qeth_core_free_card(card)
if (card->dev) !!!
free_netdev(card->dev)

Fix it by free'ing the netdev straight after unregistering. This also
fixes the sysfs-driven layer switch case (qeth_dev_layer2_store()),
where the need to free the current netdevice was not considered at all.

Note that free_netdev() takes care of the netif_napi_del() for us too.

Fixes: 4a71df50047f ("qeth: new qeth device driver")
Signed-off-by: Julian Wiedmann <jwi@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Ursula Braun <ubraun@xxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/s390/net/qeth_core_main.c | 2 --
drivers/s390/net/qeth_l2_main.c | 2 +-
drivers/s390/net/qeth_l3_main.c | 2 +-
3 files changed, 2 insertions(+), 4 deletions(-)

--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -4857,8 +4857,6 @@ static void qeth_core_free_card(struct q
QETH_DBF_HEX(SETUP, 2, &card, sizeof(void *));
qeth_clean_channel(&card->read);
qeth_clean_channel(&card->write);
- if (card->dev)
- free_netdev(card->dev);
kfree(card->ip_tbd_list);
qeth_free_qdio_buffers(card);
unregister_service_level(&card->qeth_service_level);
--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c
@@ -922,8 +922,8 @@ static void qeth_l2_remove_device(struct
qeth_l2_set_offline(cgdev);

if (card->dev) {
- netif_napi_del(&card->napi);
unregister_netdev(card->dev);
+ free_netdev(card->dev);
card->dev = NULL;
}
return;
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -3340,8 +3340,8 @@ static void qeth_l3_remove_device(struct
qeth_l3_set_offline(cgdev);

if (card->dev) {
- netif_napi_del(&card->napi);
unregister_netdev(card->dev);
+ free_netdev(card->dev);
card->dev = NULL;
}