This is a note to let you know that I've just added the patch titled
ibmvnic: avoid calling napi_disable() twice
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ibmvnic-avoid-calling-napi_disable-twice.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 0775ebc4cf8554bdcd2c212669a0868ab68df5c0 Mon Sep 17 00:00:00 2001
From: Lijun Pan <lijunp213@xxxxxxxxx>
Date: Wed, 14 Apr 2021 02:46:14 -0500
Subject: ibmvnic: avoid calling napi_disable() twice
From: Lijun Pan <lijunp213@xxxxxxxxx>
commit 0775ebc4cf8554bdcd2c212669a0868ab68df5c0 upstream.
__ibmvnic_open calls napi_disable without checking whether NAPI polling
has already been disabled or not. This could cause napi_disable
being called twice, which could generate deadlock. For example,
the first napi_disable will spin until NAPI_STATE_SCHED is cleared
by napi_complete_done, then set it again.
When napi_disable is called the second time, it will loop infinitely
because no dev->poll will be running to clear NAPI_STATE_SCHED.
To prevent above scenario from happening, call ibmvnic_napi_disable()
which checks if napi is disabled or not before calling napi_disable.
Fixes: bfc32f297337 ("ibmvnic: Move resource initialization to its own routine")
Suggested-by: Thomas Falcon <tlfalcon@xxxxxxxxxxxxx>
Signed-off-by: Lijun Pan <lijunp213@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/ibm/ibmvnic.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -891,8 +891,7 @@ static int __ibmvnic_open(struct net_dev
rc = set_link_state(adapter, IBMVNIC_LOGICAL_LNK_UP);
if (rc) {
- for (i = 0; i < adapter->req_rx_queues; i++)
- napi_disable(&adapter->napi[i]);
+ ibmvnic_napi_disable(adapter);
release_resources(adapter);
return rc;
}
Patches currently in stable-queue which might be from lijunp213@xxxxxxxxx are
queue-4.14/ibmvnic-remove-duplicate-napi_schedule-call-in-open-function.patch
queue-4.14/ibmvnic-avoid-calling-napi_disable-twice.patch
queue-4.14/ibmvnic-remove-duplicate-napi_schedule-call-in-do_reset-function.patch
