From: Jack Morgenstein Date: Fri, 3 Aug 2012 08:26:45 +0000 (+0000) Subject: IB/mlx4: Fix possible deadlock on sm_lock spinlock X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=df7fba66471c6bbbaebb55e1bb3658eb7ce00a9b;p=openwrt%2Fstaging%2Fblogic.git 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: [] update_sm_ah+0xad/0x100 [mlx4_ib] {HARDIRQ-ON-W} state was registered at: [] mark_irqflags+0x120/0x190 [] __lock_acquire+0x307/0x4c0 [] lock_acquire+0xb1/0x150 [] _raw_spin_lock+0x41/0x50 [] mlx4_ib_modify_device+0x63/0x240 [mlx4_ib] [] ib_modify_device+0x1c/0x20 [ib_core] [] set_node_desc+0x83/0xc0 [ib_core] [] dev_attr_store+0x20/0x30 [] sysfs_write_file+0xe6/0x170 [] vfs_write+0xc8/0x190 [] sys_write+0x51/0x90 [] 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: [] print_usage_bug+0x18a/0x190 [] ? print_irq_inversion_bug+0x210/0x210 [] mark_lock_irq+0xf2/0x280 [] mark_lock+0x150/0x240 [] mark_irqflags+0x16f/0x190 [] __lock_acquire+0x307/0x4c0 [] ? update_sm_ah+0xad/0x100 [mlx4_ib] [] lock_acquire+0xb1/0x150 [] ? update_sm_ah+0xad/0x100 [mlx4_ib] [] _raw_spin_lock+0x41/0x50 [] ? update_sm_ah+0xad/0x100 [mlx4_ib] [] ? ib_create_ah+0x1a/0x40 [ib_core] [] update_sm_ah+0xad/0x100 [mlx4_ib] [] ? is_module_address+0x23/0x30 [] handle_port_mgmt_change_event+0xeb/0x150 [mlx4_ib] [] mlx4_ib_event+0x117/0x160 [mlx4_ib] [] ? _raw_spin_lock_irqsave+0x61/0x70 [] mlx4_dispatch_event+0x6c/0x90 [mlx4_core] [] mlx4_eq_int+0x500/0x950 [mlx4_core] Reported by: Or Gerlitz Tested-by: Bart Van Assche Signed-off-by: Jack Morgenstein Signed-off-by: Roland Dreier --- diff --git a/drivers/infiniband/hw/mlx4/mad.c b/drivers/infiniband/hw/mlx4/mad.c index c27141fef1ab..9c2ae7efd00f 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 fe2088cfa6ee..cc05579ebce7 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