diff options
| author | Keith Busch <keith.busch@intel.com> | 2016-08-23 16:36:42 -0500 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2016-08-23 16:36:42 -0500 |
| commit | 21c80c9fefc3db10b530a96eb0478c29eb28bf77 (patch) | |
| tree | f04f76432839643639668f8b9e011fa3dffdf741 /arch | |
| parent | 5d0bdf2867825a92c0a563957a2fb059149ab0d4 (diff) | |
| download | linux-21c80c9fefc3db10b530a96eb0478c29eb28bf77.tar.bz2 | |
x86/PCI: VMD: Fix infinite loop executing irq's
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: 97e923063575 ("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>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/pci/vmd.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/arch/x86/pci/vmd.c b/arch/x86/pci/vmd.c index b814ca675131..7948be342ee9 100644 --- a/arch/x86/pci/vmd.c +++ b/arch/x86/pci/vmd.c @@ -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); - list_del_rcu(&vmdirq->node); - INIT_LIST_HEAD_RCU(&vmdirq->node); + if (vmdirq->enabled) { + list_del_rcu(&vmdirq->node); + vmdirq->enabled = false; + } raw_spin_unlock_irqrestore(&list_lock, flags); } |