diff options
| author | Keith Busch <keith.busch@intel.com> | 2016-08-05 00:09:09 +0200 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2016-09-19 20:14:05 +0200 |
| commit | ee6ee49fd09fa17c92aadf07961d0ff406fceab8 (patch) | |
| tree | b159d9b1004faceb210b73be19dd66125e964d43 /arch/x86/pci | |
| parent | x86/PCI: VMD: Eliminate index member from IRQ list (diff) | |
| download | linux-ee6ee49fd09fa17c92aadf07961d0ff406fceab8.tar.xz linux-ee6ee49fd09fa17c92aadf07961d0ff406fceab8.zip | |
x86/PCI: VMD: Synchronize with RCU freeing MSI IRQ descs
Fix a potential race when disabling MSI/MSI-X on a VMD domain device. If
the VMD interrupt service is running, it may see a disabled IRQ. We can
synchronize RCU just before freeing the MSI descriptor. This is safe since
the irq_desc lock isn't held, and the descriptor is valid even though it is
disabled. After vmd_msi_free(), though, the handler is reinitialized to
handle_bad_irq(), so we can't let the VMD ISR's list iteration see the
disabled IRQ after this.
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/x86/pci')
| -rw-r--r-- | arch/x86/pci/vmd.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/pci/vmd.c b/arch/x86/pci/vmd.c index e785907acb79..57058520f219 100644 --- a/arch/x86/pci/vmd.c +++ b/arch/x86/pci/vmd.c @@ -218,6 +218,8 @@ static void vmd_msi_free(struct irq_domain *domain, struct vmd_irq *vmdirq = irq_get_chip_data(virq); unsigned long flags; + synchronize_rcu(); + /* XXX: Potential optimization to rebalance */ raw_spin_lock_irqsave(&list_lock, flags); vmdirq->irq->count--; |