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Code Issues Releases Wiki Activity

s390/qdio: fix roll-back after timeout on ESTABLISH ccw

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When qdio_establish() times out while waiting for the ESTABLISH ccw to
complete, it calls qdio_shutdown() to roll back all of its previous
actions. But at this point the qdio_irq's state is still
QDIO_IRQ_STATE_INACTIVE, so qdio_shutdown() will exit immediately
without doing any actual work.

Which means that eg. the qdio_irq's thinint-indicator stays registered,
and cdev->handler isn't restored to its old value. And since
commit 954d6235be ("s390/qdio: make thinint registration symmetric")
the qdio_irq also stays on the tiq_list, so on the next qdio_establish()
we might get a helpful BUG from the list-debugging code:

...
[ 4633.512591] list_add double add: new=00000000005a4110, prev=00000001b357db78, next=00000000005a4110.
[ 4633.512621] ------------[ cut here ]------------
[ 4633.512623] kernel BUG at lib/list_debug.c:29!
...
[ 4633.512796]  [<00000001b2c6ee9a>] __list_add_valid+0x82/0xa0
[ 4633.512798] ([<00000001b2c6ee96>] __list_add_valid+0x7e/0xa0)
[ 4633.512800]  [<00000001b2fcecce>] qdio_establish_thinint+0x116/0x190
[ 4633.512805]  [<00000001b2fcbe58>] qdio_establish+0x128/0x498
...

Fix this by extracting a goto-chain from the existing error exits in
qdio_establish(), and check the return value of the wait_event_...()
to detect the timeout condition.

Fixes: 779e6e1c72 ("[S390] qdio: new qdio driver.")
Root-caused-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Cc: <stable@vger.kernel.org> # 2.6.27
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
This commit is contained in:
Julian Wiedmann 2021-05-31 18:40:06 +03:00 committed by Heiko Carstens
parent f1a5469474
commit 2c197870e4
1 changed files with 19 additions and 12 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

31
drivers/s390/cio/qdio_main.c
View file

@ -1083,6 +1083,7 @@ int qdio_establish(struct ccw_device *cdev,
{
struct qdio_irq *irq_ptr = cdev->private->qdio_data;
struct subchannel_id schid;
long timeout;
int rc;
ccw_device_get_schid(cdev, &schid);
@ -1111,11 +1112,8 @@ int qdio_establish(struct ccw_device *cdev,
qdio_setup_irq(irq_ptr, init_data);
rc = qdio_establish_thinint(irq_ptr);
if (rc) {
qdio_shutdown_irq(irq_ptr);
mutex_unlock(&irq_ptr->setup_mutex);
return rc;
}
if (rc)
goto err_thinint;
/* establish q */
irq_ptr->ccw.cmd_code = irq_ptr->equeue.cmd;
@ -1131,15 +1129,16 @@ int qdio_establish(struct ccw_device *cdev,
if (rc) {
DBF_ERROR("%4x est IO ERR", irq_ptr->schid.sch_no);
DBF_ERROR("rc:%4x", rc);
qdio_shutdown_thinint(irq_ptr);
qdio_shutdown_irq(irq_ptr);
mutex_unlock(&irq_ptr->setup_mutex);
return rc;
goto err_ccw_start;
}
wait_event_interruptible_timeout(cdev->private->wait_q,
irq_ptr->state == QDIO_IRQ_STATE_ESTABLISHED ||
irq_ptr->state == QDIO_IRQ_STATE_ERR, HZ);
timeout = wait_event_interruptible_timeout(cdev->private->wait_q,
irq_ptr->state == QDIO_IRQ_STATE_ESTABLISHED ||
irq_ptr->state == QDIO_IRQ_STATE_ERR, HZ);
if (timeout <= 0) {
rc = (timeout == -ERESTARTSYS) ? -EINTR : -ETIME;
goto err_ccw_timeout;
}
if (irq_ptr->state != QDIO_IRQ_STATE_ESTABLISHED) {
mutex_unlock(&irq_ptr->setup_mutex);
@ -1156,6 +1155,14 @@ int qdio_establish(struct ccw_device *cdev,
qdio_print_subchannel_info(irq_ptr);
qdio_setup_debug_entries(irq_ptr);
return 0;
err_ccw_timeout:
err_ccw_start:
qdio_shutdown_thinint(irq_ptr);
err_thinint:
qdio_shutdown_irq(irq_ptr);
mutex_unlock(&irq_ptr->setup_mutex);
return rc;
}
EXPORT_SYMBOL_GPL(qdio_establish);