From: Thomas Falcon tlfalcon@linux.ibm.com
[ Upstream commit 6c5c7489089608d89b7ce310bca44812e2b0a4a5 ]
ibmvnic_reset can create and schedule a reset work item from an IRQ context, so do not use a mutex, which can sleep. Convert the reset work item mutex to a spin lock. Locking debugger generated the trace output below.
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:908 in_atomic(): 1, irqs_disabled(): 1, pid: 120, name: kworker/8:1 4 locks held by kworker/8:1/120: #0: 0000000017c05720 ((wq_completion)"events"){+.+.}, at: process_one_work+0x188/0x710 #1: 00000000ace90706 ((linkwatch_work).work){+.+.}, at: process_one_work+0x188/0x710 #2: 000000007632871f (rtnl_mutex){+.+.}, at: rtnl_lock+0x30/0x50 #3: 00000000fc36813a (&(&crq->lock)->rlock){..-.}, at: ibmvnic_tasklet+0x88/0x2010 [ibmvnic] irq event stamp: 26293 hardirqs last enabled at (26292): [<c000000000122468>] tasklet_action_common.isra.12+0x78/0x1c0 hardirqs last disabled at (26293): [<c000000000befce8>] _raw_spin_lock_irqsave+0x48/0xf0 softirqs last enabled at (26288): [<c000000000a8ac78>] dev_deactivate_queue.constprop.28+0xc8/0x160 softirqs last disabled at (26289): [<c0000000000306e0>] call_do_softirq+0x14/0x24 CPU: 8 PID: 120 Comm: kworker/8:1 Kdump: loaded Not tainted 4.20.0-rc6 #6 Workqueue: events linkwatch_event Call Trace: [c0000003fffa7a50] [c000000000bc83e4] dump_stack+0xe8/0x164 (unreliable) [c0000003fffa7aa0] [c00000000015ba0c] ___might_sleep+0x2dc/0x320 [c0000003fffa7b20] [c000000000be960c] __mutex_lock+0x8c/0xb40 [c0000003fffa7c30] [d000000006202ac8] ibmvnic_reset+0x78/0x330 [ibmvnic] [c0000003fffa7cc0] [d0000000062097f4] ibmvnic_tasklet+0x1054/0x2010 [ibmvnic] [c0000003fffa7e00] [c0000000001224c8] tasklet_action_common.isra.12+0xd8/0x1c0 [c0000003fffa7e60] [c000000000bf1238] __do_softirq+0x1a8/0x64c [c0000003fffa7f90] [c0000000000306e0] call_do_softirq+0x14/0x24 [c0000003f3f87980] [c00000000001ba50] do_softirq_own_stack+0x60/0xb0 [c0000003f3f879c0] [c0000000001218a8] do_softirq+0xa8/0x100 [c0000003f3f879f0] [c000000000121a74] __local_bh_enable_ip+0x174/0x180 [c0000003f3f87a60] [c000000000bf003c] _raw_spin_unlock_bh+0x5c/0x80 [c0000003f3f87a90] [c000000000a8ac78] dev_deactivate_queue.constprop.28+0xc8/0x160 [c0000003f3f87ad0] [c000000000a8c8b0] dev_deactivate_many+0xd0/0x520 [c0000003f3f87b70] [c000000000a8cd40] dev_deactivate+0x40/0x60 [c0000003f3f87ba0] [c000000000a5e0c4] linkwatch_do_dev+0x74/0xd0 [c0000003f3f87bd0] [c000000000a5e694] __linkwatch_run_queue+0x1a4/0x1f0 [c0000003f3f87c30] [c000000000a5e728] linkwatch_event+0x48/0x60 [c0000003f3f87c50] [c0000000001444e8] process_one_work+0x238/0x710 [c0000003f3f87d20] [c000000000144a48] worker_thread+0x88/0x4e0 [c0000003f3f87db0] [c00000000014e3a8] kthread+0x178/0x1c0 [c0000003f3f87e20] [c00000000000bfd0] ret_from_kernel_thread+0x5c/0x6c
Signed-off-by: Thomas Falcon tlfalcon@linux.ibm.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/ibm/ibmvnic.c | 16 +++++++++------- drivers/net/ethernet/ibm/ibmvnic.h | 2 +- 2 files changed, 10 insertions(+), 8 deletions(-)
diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c index 5ab21a1b5444..5058bd83bdd6 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.c +++ b/drivers/net/ethernet/ibm/ibmvnic.c @@ -1939,8 +1939,9 @@ static int do_hard_reset(struct ibmvnic_adapter *adapter, static struct ibmvnic_rwi *get_next_rwi(struct ibmvnic_adapter *adapter) { struct ibmvnic_rwi *rwi; + unsigned long flags;
- mutex_lock(&adapter->rwi_lock); + spin_lock_irqsave(&adapter->rwi_lock, flags);
if (!list_empty(&adapter->rwi_list)) { rwi = list_first_entry(&adapter->rwi_list, struct ibmvnic_rwi, @@ -1950,7 +1951,7 @@ static struct ibmvnic_rwi *get_next_rwi(struct ibmvnic_adapter *adapter) rwi = NULL; }
- mutex_unlock(&adapter->rwi_lock); + spin_unlock_irqrestore(&adapter->rwi_lock, flags); return rwi; }
@@ -2025,6 +2026,7 @@ static int ibmvnic_reset(struct ibmvnic_adapter *adapter, struct list_head *entry, *tmp_entry; struct ibmvnic_rwi *rwi, *tmp; struct net_device *netdev = adapter->netdev; + unsigned long flags; int ret;
if (adapter->state == VNIC_REMOVING || @@ -2041,13 +2043,13 @@ static int ibmvnic_reset(struct ibmvnic_adapter *adapter, goto err; }
- mutex_lock(&adapter->rwi_lock); + spin_lock_irqsave(&adapter->rwi_lock, flags);
list_for_each(entry, &adapter->rwi_list) { tmp = list_entry(entry, struct ibmvnic_rwi, list); if (tmp->reset_reason == reason) { netdev_dbg(netdev, "Skipping matching reset\n"); - mutex_unlock(&adapter->rwi_lock); + spin_unlock_irqrestore(&adapter->rwi_lock, flags); ret = EBUSY; goto err; } @@ -2055,7 +2057,7 @@ static int ibmvnic_reset(struct ibmvnic_adapter *adapter,
rwi = kzalloc(sizeof(*rwi), GFP_KERNEL); if (!rwi) { - mutex_unlock(&adapter->rwi_lock); + spin_unlock_irqrestore(&adapter->rwi_lock, flags); ibmvnic_close(netdev); ret = ENOMEM; goto err; @@ -2069,7 +2071,7 @@ static int ibmvnic_reset(struct ibmvnic_adapter *adapter, } rwi->reset_reason = reason; list_add_tail(&rwi->list, &adapter->rwi_list); - mutex_unlock(&adapter->rwi_lock); + spin_unlock_irqrestore(&adapter->rwi_lock, flags); adapter->resetting = true; netdev_dbg(adapter->netdev, "Scheduling reset (reason %d)\n", reason); schedule_work(&adapter->ibmvnic_reset); @@ -4700,7 +4702,7 @@ static int ibmvnic_probe(struct vio_dev *dev, const struct vio_device_id *id)
INIT_WORK(&adapter->ibmvnic_reset, __ibmvnic_reset); INIT_LIST_HEAD(&adapter->rwi_list); - mutex_init(&adapter->rwi_lock); + spin_lock_init(&adapter->rwi_lock); adapter->resetting = false;
adapter->mac_change_pending = false; diff --git a/drivers/net/ethernet/ibm/ibmvnic.h b/drivers/net/ethernet/ibm/ibmvnic.h index 735f481b1870..09465397b7ff 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.h +++ b/drivers/net/ethernet/ibm/ibmvnic.h @@ -1068,7 +1068,7 @@ struct ibmvnic_adapter { struct tasklet_struct tasklet; enum vnic_state state; enum ibmvnic_reset_reason reset_reason; - struct mutex rwi_lock; + spinlock_t rwi_lock; struct list_head rwi_list; struct work_struct ibmvnic_reset; bool resetting;