diff options
author | Julian Wiedmann <jwi@linux.ibm.com> | 2021-01-07 18:24:41 +0100 |
---|---|---|
committer | Jakub Kicinski <kuba@kernel.org> | 2021-01-07 18:54:06 -0800 |
commit | b41b554c1ee75070a14c02a88496b1f231c7eacc (patch) | |
tree | 640acf6ee4ddeb467d832a99b68242f35deaa7ae | |
parent | 0b9902c1fcc59ba75268386c0420a554f8844168 (diff) |
s390/qeth: fix locking for discipline setup / removal
Due to insufficient locking, qeth_core_set_online() and
qeth_dev_layer2_store() can run in parallel, both attempting to load &
setup the discipline (and stepping on each other toes along the way).
A similar race can also occur between qeth_core_remove_device() and
qeth_dev_layer2_store().
Access to .discipline is meant to be protected by the discipline_mutex,
so add/expand the locking in qeth_core_remove_device() and
qeth_core_set_online().
Adjust the locking in qeth_l*_remove_device() accordingly, as it's now
handled by the callers in a consistent manner.
Based on an initial patch by Ursula Braun.
Fixes: 9dc48ccc68b9 ("qeth: serialize sysfs-triggered device configurations")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
-rw-r--r-- | drivers/s390/net/qeth_core_main.c | 7 | ||||
-rw-r--r-- | drivers/s390/net/qeth_l2_main.c | 5 | ||||
-rw-r--r-- | drivers/s390/net/qeth_l3_main.c | 5 |
3 files changed, 7 insertions, 10 deletions
diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c index d45e223fc521..cf18d87da41e 100644 --- a/drivers/s390/net/qeth_core_main.c +++ b/drivers/s390/net/qeth_core_main.c @@ -6585,6 +6585,7 @@ static int qeth_core_probe_device(struct ccwgroup_device *gdev) break; default: card->info.layer_enforced = true; + /* It's so early that we don't need the discipline_mutex yet. */ rc = qeth_core_load_discipline(card, enforced_disc); if (rc) goto err_load; @@ -6617,10 +6618,12 @@ static void qeth_core_remove_device(struct ccwgroup_device *gdev) QETH_CARD_TEXT(card, 2, "removedv"); + mutex_lock(&card->discipline_mutex); if (card->discipline) { card->discipline->remove(gdev); qeth_core_free_discipline(card); } + mutex_unlock(&card->discipline_mutex); qeth_free_qdio_queues(card); @@ -6635,6 +6638,7 @@ static int qeth_core_set_online(struct ccwgroup_device *gdev) int rc = 0; enum qeth_discipline_id def_discipline; + mutex_lock(&card->discipline_mutex); if (!card->discipline) { def_discipline = IS_IQD(card) ? QETH_DISCIPLINE_LAYER3 : QETH_DISCIPLINE_LAYER2; @@ -6648,11 +6652,10 @@ static int qeth_core_set_online(struct ccwgroup_device *gdev) } } - mutex_lock(&card->discipline_mutex); rc = qeth_set_online(card, card->discipline); - mutex_unlock(&card->discipline_mutex); err: + mutex_unlock(&card->discipline_mutex); return rc; } diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c index 37279b1e29f6..4254caf1d9b6 100644 --- a/drivers/s390/net/qeth_l2_main.c +++ b/drivers/s390/net/qeth_l2_main.c @@ -2207,11 +2207,8 @@ static void qeth_l2_remove_device(struct ccwgroup_device *gdev) qeth_set_allowed_threads(card, 0, 1); wait_event(card->wait_q, qeth_threads_running(card, 0xffffffff) == 0); - if (gdev->state == CCWGROUP_ONLINE) { - mutex_lock(&card->discipline_mutex); + if (gdev->state == CCWGROUP_ONLINE) qeth_set_offline(card, card->discipline, false); - mutex_unlock(&card->discipline_mutex); - } cancel_work_sync(&card->close_dev_work); if (card->dev->reg_state == NETREG_REGISTERED) diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c index 8d474179ce98..6970597bc885 100644 --- a/drivers/s390/net/qeth_l3_main.c +++ b/drivers/s390/net/qeth_l3_main.c @@ -1970,11 +1970,8 @@ static void qeth_l3_remove_device(struct ccwgroup_device *cgdev) qeth_set_allowed_threads(card, 0, 1); wait_event(card->wait_q, qeth_threads_running(card, 0xffffffff) == 0); - if (cgdev->state == CCWGROUP_ONLINE) { - mutex_lock(&card->discipline_mutex); + if (cgdev->state == CCWGROUP_ONLINE) qeth_set_offline(card, card->discipline, false); - mutex_unlock(&card->discipline_mutex); - } cancel_work_sync(&card->close_dev_work); if (card->dev->reg_state == NETREG_REGISTERED) |