Jack Morgenstein
d546b67cda
spin_lock/unlock was used instead of spin_un/lock_irq
in a procedure used in process space, on a spinlock
which can be grabbed in an interrupt.
This caused the stack trace below to be displayed (on kernel
4.17.0-rc1 compiled with Lock Debugging enabled):
[ 154.661474] WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
[ 154.668909] 4.17.0-rc1-rdma_rc_mlx+ #3 Tainted: G I
[ 154.675856] -----------------------------------------------------
[ 154.682706] modprobe/10159 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
[ 154.690254] 00000000f3b0e495 (&(&qp_table->lock)->rlock){+.+.}, at: mlx4_qp_remove+0x20/0x50 [mlx4_core]
[ 154.700927]
and this task is already holding:
[ 154.707461] 0000000094373b5d (&(&cq->lock)->rlock/1){....}, at: destroy_qp_common+0x111/0x560 [mlx4_ib]
[ 154.718028] which would create a new lock dependency:
[ 154.723705] (&(&cq->lock)->rlock/1){....} -> (&(&qp_table->lock)->rlock){+.+.}
[ 154.731922]
but this new dependency connects a SOFTIRQ-irq-safe lock:
[ 154.740798] (&(&cq->lock)->rlock){..-.}
[ 154.740800]
... which became SOFTIRQ-irq-safe at:
[ 154.752163] _raw_spin_lock_irqsave+0x3e/0x50
[ 154.757163] mlx4_ib_poll_cq+0x36/0x900 [mlx4_ib]
[ 154.762554] ipoib_tx_poll+0x4a/0xf0 [ib_ipoib]
...
to a SOFTIRQ-irq-unsafe lock:
[ 154.815603] (&(&qp_table->lock)->rlock){+.+.}
[ 154.815604]
... which became SOFTIRQ-irq-unsafe at:
[ 154.827718] ...
[ 154.827720] _raw_spin_lock+0x35/0x50
[ 154.833912] mlx4_qp_lookup+0x1e/0x50 [mlx4_core]
[ 154.839302] mlx4_flow_attach+0x3f/0x3d0 [mlx4_core]
Since mlx4_qp_lookup() is called only in process space, we can
simply replace the spin_un/lock calls with spin_un/lock_irq calls.
Fixes: 6dc06c08be ("net/mlx4: Fix the check in attaching steering rules")
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel
============
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