net/mlx5e: Fix possible deadlock of VXLAN lock
mlx5e_vxlan_lookup_port is called both from mlx5e_add_vxlan_port (user context) and mlx5e_features_check (softirq), but the lock acquired does not disable bottom half and might result in deadlock. Fix it by simply replacing spin_lock() with spin_lock_bh(). While at it, replace all unnecessary spin_lock_irq() to spin_lock_bh(). lockdep's WARNING: inconsistent lock state [ 654.028136] inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. [ 654.028229] swapper/5/0 [HC0[0]:SC1[9]:HE1:SE0] takes: [ 654.028321] (&(&vxlan_db->lock)->rlock){+.?.}, at: [<ffffffffa06e7f0e>] mlx5e_vxlan_lookup_port+0x1e/0x50 [mlx5_core] [ 654.028528] {SOFTIRQ-ON-W} state was registered at: [ 654.028607] _raw_spin_lock+0x3c/0x70 [ 654.028689] mlx5e_vxlan_lookup_port+0x1e/0x50 [mlx5_core] [ 654.028794] mlx5e_vxlan_add_port+0x2e/0x120 [mlx5_core] [ 654.028878] process_one_work+0x1e9/0x640 [ 654.028942] worker_thread+0x4a/0x3f0 [ 654.029002] kthread+0x141/0x180 [ 654.029056] ret_from_fork+0x24/0x30 [ 654.029114] irq event stamp: 579088 [ 654.029174] hardirqs last enabled at (579088): [<ffffffff818f475a>] ip6_finish_output2+0x49a/0x8c0 [ 654.029309] hardirqs last disabled at (579087): [<ffffffff818f470e>] ip6_finish_output2+0x44e/0x8c0 [ 654.029446] softirqs last enabled at (579030): [<ffffffff810b3b3d>] irq_enter+0x6d/0x80 [ 654.029567] softirqs last disabled at (579031): [<ffffffff810b3c05>] irq_exit+0xb5/0xc0 [ 654.029684] other info that might help us debug this: [ 654.029781] Possible unsafe locking scenario: [ 654.029868] CPU0 [ 654.029908] ---- [ 654.029947] lock(&(&vxlan_db->lock)->rlock); [ 654.030045] <Interrupt> [ 654.030090] lock(&(&vxlan_db->lock)->rlock); [ 654.030162] *** DEADLOCK *** Fixes: b3f63c3d ("net/mlx5e: Add netdev support for VXLAN tunneling") Signed-off-by: Gal Pressman <galp@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
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