x86/PCI: VMD: Fix infinite loop executing irq's (21c80c9f) · Commits · 戴 / test

We can't initialize the list head on deletion as this causes the node to point to itself, which causes an infinite loop if vmd_irq() happens to be servicing that node. The list initialization was trying to fix a bug from multiple calls to disable the same IRQ. Fix this instead by having the VMD driver track if the interrupt is enabled. [bhelgaas: changelog, add "Fixes"] Fixes: ("x86/PCI: VMD: Initialize list item in IRQ disable") Reported-by:

Grzegorz Koczot <grzegorz.koczot@intel.com> Tested-by:

Miroslaw Drost <miroslaw.drost@intel.com> Signed-off-by:

Keith Busch <keith.busch@intel.com> Signed-off-by:

Bjorn Helgaas <bhelgaas@google.com> Acked-by Jon Derrick: <jonathan.derrick@intel.com>

arch/x86/pci/vmd.c

+8 −2

Original line number	Diff line number	Diff line
		@@ -41,6 +41,7 @@ static DEFINE_RAW_SPINLOCK(list_lock);
		* @node: list item for parent traversal.
		* @rcu: RCU callback item for freeing.
		* @irq: back pointer to parent.
		* @enabled: true if driver enabled IRQ
		* @virq: the virtual IRQ value provided to the requesting driver.
		*
		* Every MSI/MSI-X IRQ requested for a device in a VMD domain will be mapped to
		@@ -50,6 +51,7 @@ struct vmd_irq {
		struct list_head node;
		struct rcu_head rcu;
		struct vmd_irq_list *irq;
		bool enabled;
		unsigned int virq;
		};

		@@ -122,7 +124,9 @@ static void vmd_irq_enable(struct irq_data *data)
		unsigned long flags;

		raw_spin_lock_irqsave(&list_lock, flags);
		WARN_ON(vmdirq->enabled);
		list_add_tail_rcu(&vmdirq->node, &vmdirq->irq->irq_list);
		vmdirq->enabled = true;
		raw_spin_unlock_irqrestore(&list_lock, flags);

		data->chip->irq_unmask(data);
		@@ -136,8 +140,10 @@ static void vmd_irq_disable(struct irq_data *data)
		data->chip->irq_mask(data);

		raw_spin_lock_irqsave(&list_lock, flags);
		if (vmdirq->enabled) {
		list_del_rcu(&vmdirq->node);
		INIT_LIST_HEAD_RCU(&vmdirq->node);
		vmdirq->enabled = false;
		}
		raw_spin_unlock_irqrestore(&list_lock, flags);
		}

Admin message