From df7fba66471c6bbbaebb55e1bb3658eb7ce00a9b Mon Sep 17 00:00:00 2001
From: Jack Morgenstein <jackm@dev.mellanox.co.il>
Date: Fri, 3 Aug 2012 08:26:45 +0000
Subject: [PATCH] IB/mlx4: Fix possible deadlock on sm_lock spinlock
The sm_lock spinlock is taken in the process context by
mlx4_ib_modify_device, and in the interrupt context by update_sm_ah,
so we need to take that spinlock with irqsave, and release it with
irqrestore.
Lockdeps reports this as follows:
[ INFO: inconsistent lock state ]
3.5.0+ #20 Not tainted
inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage.
swapper/0/0 [HC1[1]:SC0[0]:HE0:SE1] takes:
(&(&ibdev->sm_lock)->rlock){?.+...}, at: [<ffffffffa028af1d>] update_sm_ah+0xad/0x100 [mlx4_ib]
{HARDIRQ-ON-W} state was registered at:
[<ffffffff810b84a0>] mark_irqflags+0x120/0x190
[<ffffffff810b9ce7>] __lock_acquire+0x307/0x4c0
[<ffffffff810b9f51>] lock_acquire+0xb1/0x150
[<ffffffff815523b1>] _raw_spin_lock+0x41/0x50
[<ffffffffa028d563>] mlx4_ib_modify_device+0x63/0x240 [mlx4_ib]
[<ffffffffa026d1fc>] ib_modify_device+0x1c/0x20 [ib_core]
[<ffffffffa026c353>] set_node_desc+0x83/0xc0 [ib_core]
[<ffffffff8136a150>] dev_attr_store+0x20/0x30
[<ffffffff81201fd6>] sysfs_write_file+0xe6/0x170
[<ffffffff8118da38>] vfs_write+0xc8/0x190
[<ffffffff8118dc01>] sys_write+0x51/0x90
[<ffffffff8155b869>] system_call_fastpath+0x16/0x1b
...
*** DEADLOCK ***
1 lock held by swapper/0/0:
stack backtrace:
Pid: 0, comm: swapper/0 Not tainted 3.5.0+ #20
Call Trace:
<IRQ> [<ffffffff810b7bea>] print_usage_bug+0x18a/0x190
[<ffffffff810b7370>] ? print_irq_inversion_bug+0x210/0x210
[<ffffffff810b7fb2>] mark_lock_irq+0xf2/0x280
[<ffffffff810b8290>] mark_lock+0x150/0x240
[<ffffffff810b84ef>] mark_irqflags+0x16f/0x190
[<ffffffff810b9ce7>] __lock_acquire+0x307/0x4c0
[<ffffffffa028af1d>] ? update_sm_ah+0xad/0x100 [mlx4_ib]
[<ffffffff810b9f51>] lock_acquire+0xb1/0x150
[<ffffffffa028af1d>] ? update_sm_ah+0xad/0x100 [mlx4_ib]
[<ffffffff815523b1>] _raw_spin_lock+0x41/0x50
[<ffffffffa028af1d>] ? update_sm_ah+0xad/0x100 [mlx4_ib]
[<ffffffffa026b2fa>] ? ib_create_ah+0x1a/0x40 [ib_core]
[<ffffffffa028af1d>] update_sm_ah+0xad/0x100 [mlx4_ib]
[<ffffffff810c27c3>] ? is_module_address+0x23/0x30
[<ffffffffa028b05b>] handle_port_mgmt_change_event+0xeb/0x150 [mlx4_ib]
[<ffffffffa028c177>] mlx4_ib_event+0x117/0x160 [mlx4_ib]
[<ffffffff81552501>] ? _raw_spin_lock_irqsave+0x61/0x70
[<ffffffffa022718c>] mlx4_dispatch_event+0x6c/0x90 [mlx4_core]
[<ffffffffa0221b40>] mlx4_eq_int+0x500/0x950 [mlx4_core]
Reported by: Or Gerlitz <ogerlitz@mellanox.com>
Tested-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <roland@purestorage.com>
---
drivers/infiniband/hw/mlx4/mad.c | 16 ++++++++++------
drivers/infiniband/hw/mlx4/main.c | 5 +++--
2 files changed, 13 insertions(+), 8 deletions(-)
diff --git a/drivers/infiniband/hw/mlx4/mad.c b/drivers/infiniband/hw/mlx4/mad.c
index c27141fef1ab2f..9c2ae7efd00f4c 100644
--- a/drivers/infiniband/hw/mlx4/mad.c
+++ b/drivers/infiniband/hw/mlx4/mad.c
@@ -125,6 +125,7 @@ static void update_sm_ah(struct mlx4_ib_dev *dev, u8 port_num, u16 lid, u8 sl)
{
struct ib_ah *new_ah;
struct ib_ah_attr ah_attr;
+ unsigned long flags;
if (!dev->send_agent[port_num - 1][0])
return;
@@ -139,11 +140,11 @@ static void update_sm_ah(struct mlx4_ib_dev *dev, u8 port_num, u16 lid, u8 sl)
if (IS_ERR(new_ah))
return;
- spin_lock(&dev->sm_lock);
+ spin_lock_irqsave(&dev->sm_lock, flags);
if (dev->sm_ah[port_num - 1])
ib_destroy_ah(dev->sm_ah[port_num - 1]);
dev->sm_ah[port_num - 1] = new_ah;
- spin_unlock(&dev->sm_lock);
+ spin_unlock_irqrestore(&dev->sm_lock, flags);
}
/*
@@ -197,13 +198,15 @@ static void smp_snoop(struct ib_device *ibdev, u8 port_num, struct ib_mad *mad,
static void node_desc_override(struct ib_device *dev,
struct ib_mad *mad)
{
+ unsigned long flags;
+
if ((mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_LID_ROUTED ||
mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE) &&
mad->mad_hdr.method == IB_MGMT_METHOD_GET_RESP &&
mad->mad_hdr.attr_id == IB_SMP_ATTR_NODE_DESC) {
- spin_lock(&to_mdev(dev)->sm_lock);
+ spin_lock_irqsave(&to_mdev(dev)->sm_lock, flags);
memcpy(((struct ib_smp *) mad)->data, dev->node_desc, 64);
- spin_unlock(&to_mdev(dev)->sm_lock);
+ spin_unlock_irqrestore(&to_mdev(dev)->sm_lock, flags);
}
}
@@ -213,6 +216,7 @@ static void forward_trap(struct mlx4_ib_dev *dev, u8 port_num, struct ib_mad *ma
struct ib_mad_send_buf *send_buf;
struct ib_mad_agent *agent = dev->send_agent[port_num - 1][qpn];
int ret;
+ unsigned long flags;
if (agent) {
send_buf = ib_create_send_mad(agent, qpn, 0, 0, IB_MGMT_MAD_HDR,
@@ -225,13 +229,13 @@ static void forward_trap(struct mlx4_ib_dev *dev, u8 port_num, struct ib_mad *ma
* wrong following the IB spec strictly, but we know
* it's OK for our devices).
*/
- spin_lock(&dev->sm_lock);
+ spin_lock_irqsave(&dev->sm_lock, flags);
memcpy(send_buf->mad, mad, sizeof *mad);
if ((send_buf->ah = dev->sm_ah[port_num - 1]))
ret = ib_post_send_mad(send_buf, NULL);
else
ret = -EINVAL;
- spin_unlock(&dev->sm_lock);
+ spin_unlock_irqrestore(&dev->sm_lock, flags);
if (ret)
ib_free_send_mad(send_buf);
diff --git a/drivers/infiniband/hw/mlx4/main.c b/drivers/infiniband/hw/mlx4/main.c
index fe2088cfa6eef6..cc05579ebce7fd 100644
--- a/drivers/infiniband/hw/mlx4/main.c
+++ b/drivers/infiniband/hw/mlx4/main.c
@@ -423,6 +423,7 @@ static int mlx4_ib_modify_device(struct ib_device *ibdev, int mask,
struct ib_device_modify *props)
{
struct mlx4_cmd_mailbox *mailbox;
+ unsigned long flags;
if (mask & ~IB_DEVICE_MODIFY_NODE_DESC)
return -EOPNOTSUPP;
@@ -430,9 +431,9 @@ static int mlx4_ib_modify_device(struct ib_device *ibdev, int mask,
if (!(mask & IB_DEVICE_MODIFY_NODE_DESC))
return 0;
- spin_lock(&to_mdev(ibdev)->sm_lock);
+ spin_lock_irqsave(&to_mdev(ibdev)->sm_lock, flags);
memcpy(ibdev->node_desc, props->node_desc, 64);
- spin_unlock(&to_mdev(ibdev)->sm_lock);
+ spin_unlock_irqrestore(&to_mdev(ibdev)->sm_lock, flags);
/*
* If possible, pass node desc to FW, so it can generate
--
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