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| author | Moni Shoua <monis@mellanox.com> | 2018-12-26 18:21:21 +0100 |
|---|---|---|
| committer | Saeed Mahameed <saeedm@mellanox.com> | 2019-01-25 21:00:28 +0100 |
| commit | 33814e5d127e21f53b52e17b0722c1b57d4f4d29 (patch) | |
| tree | 9fdb2f476fc7ae022cf262632bb079e224fbeaea /drivers | |
| parent | net/mlx5e: Fix wrong private flag usage causing checksum disable (diff) | |
| download | linux-33814e5d127e21f53b52e17b0722c1b57d4f4d29.tar.xz linux-33814e5d127e21f53b52e17b0722c1b57d4f4d29.zip | |
net/mlx5: Take lock with IRQs disabled to avoid deadlock
The lock in qp_table might be taken from process context or from
interrupt context. This may lead to a deadlock unless it is taken with
IRQs disabled.
Discovered by lockdep
================================
WARNING: inconsistent lock state
4.20.0-rc6
--------------------------------
inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W}
python/12572 [HC1[1]:SC0[0]:HE0:SE1] takes:
00000000052a4df4 (&(&table->lock)->rlock#2){?.+.}, /0x50 [mlx5_core]
{HARDIRQ-ON-W} state was registered at:
_raw_spin_lock+0x33/0x70
mlx5_get_rsc+0x1a/0x50 [mlx5_core]
mlx5_ib_eqe_pf_action+0x493/0x1be0 [mlx5_ib]
process_one_work+0x90c/0x1820
worker_thread+0x87/0xbb0
kthread+0x320/0x3e0
ret_from_fork+0x24/0x30
irq event stamp: 103928
hardirqs last enabled at (103927): [] nk+0x1a/0x1c
hardirqs last disabled at (103928): [] unk+0x1a/0x1c
softirqs last enabled at (103924): [] tcp_sendmsg+0x31/0x40
softirqs last disabled at (103922): [] 80
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&(&table->lock)->rlock#2);
lock(&(&table->lock)->rlock#2);
*** DEADLOCK ***
Fixes: 032080ab43ac ("IB/mlx5: Lock QP during page fault handling")
Signed-off-by: Moni Shoua <monis@mellanox.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/ethernet/mellanox/mlx5/core/qp.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/qp.c b/drivers/net/ethernet/mellanox/mlx5/core/qp.c index 388f205a497f..370ca94b6775 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/qp.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/qp.c @@ -44,14 +44,15 @@ static struct mlx5_core_rsc_common * mlx5_get_rsc(struct mlx5_qp_table *table, u32 rsn) { struct mlx5_core_rsc_common *common; + unsigned long flags; - spin_lock(&table->lock); + spin_lock_irqsave(&table->lock, flags); common = radix_tree_lookup(&table->tree, rsn); if (common) atomic_inc(&common->refcount); - spin_unlock(&table->lock); + spin_unlock_irqrestore(&table->lock, flags); return common; } |