From: Moshe Shemesh moshe@mellanox.com
[ Upstream commit 6377ed0bbae6fa28853e1679d068a9106c8a8908 ]
spin_lock/unlock of health->wq_lock should be IRQ safe. It was changed to spin_lock_irqsave since adding commit 0179720d6be2 ("net/mlx5: Introduce trigger_health_work function") which uses spin_lock from asynchronous event (IRQ) context. Thus, all spin_lock/unlock of health->wq_lock should have been moved to IRQ safe mode. However, one occurrence on new code using this lock missed that change, resulting in possible deadlock: kernel: Possible unsafe locking scenario: kernel: CPU0 kernel: ---- kernel: lock(&(&health->wq_lock)->rlock); kernel: <Interrupt> kernel: lock(&(&health->wq_lock)->rlock); kernel: #012 *** DEADLOCK ***
Fixes: 2a0165a034ac ("net/mlx5: Cancel delayed recovery work when unloading the driver") Signed-off-by: Moshe Shemesh moshe@mellanox.com Signed-off-by: Saeed Mahameed saeedm@mellanox.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/mellanox/mlx5/core/health.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/health.c b/drivers/net/ethernet/mellanox/mlx5/core/health.c index 448e71e07668..264f51b3409d 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/health.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/health.c @@ -369,10 +369,11 @@ void mlx5_drain_health_wq(struct mlx5_core_dev *dev) void mlx5_drain_health_recovery(struct mlx5_core_dev *dev) { struct mlx5_core_health *health = &dev->priv.health; + unsigned long flags;
- spin_lock(&health->wq_lock); + spin_lock_irqsave(&health->wq_lock, flags); set_bit(MLX5_DROP_NEW_RECOVERY_WORK, &health->flags); - spin_unlock(&health->wq_lock); + spin_unlock_irqrestore(&health->wq_lock, flags); cancel_delayed_work_sync(&dev->priv.health.recover_work); }