diff options
| author | David Woodhouse <dwmw@amazon.co.uk> | 2021-01-05 01:36:13 +0000 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2021-01-05 19:24:12 +0000 |
| commit | b34f10c2dc5961021850c3c15f46a84b56a0c0e8 (patch) | |
| tree | c4e48bfe7876269071983825fd99f56f0589b29d /drivers/iommu/amd | |
| parent | 12bc4570c14e24e6244d66466aeda994f805634b (diff) | |
iommu/amd: Stop irq_remapping_select() matching when remapping is disabled
The AMD IOMMU initialisation registers the IRQ remapping domain for
each IOMMU before doing the final sanity check that every I/OAPIC is
covered.
This means that the AMD irq_remapping_select() function gets invoked
even when IRQ remapping has been disabled, eventually leading to a NULL
pointer dereference in alloc_irq_table().
Unfortunately, the IVRS isn't fully parsed early enough that the sanity
check can be done in time to registering the IRQ domain altogether.
Doing that would be nice, but is a larger and more error-prone task. The
simple fix is just for irq_remapping_select() to refuse to report a
match when IRQ remapping has disabled.
Link: https://lore.kernel.org/lkml/ed4be9b4-24ac-7128-c522-7ef359e8185d@gmx.at
Fixes: a1a785b57242 ("iommu/amd: Implement select() method on remapping irqdomain")
Reported-by: Johnathan Smithinovic <johnathan.smithinovic@gmx.at>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lore.kernel.org/r/04bbe8bca87f81a3cfa93ec4299e53f47e00e5b3.camel@infradead.org
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'drivers/iommu/amd')
| -rw-r--r-- | drivers/iommu/amd/iommu.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c index 7e2c445a1fae..f0adbc48fd17 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -3854,6 +3854,9 @@ static int irq_remapping_select(struct irq_domain *d, struct irq_fwspec *fwspec, struct amd_iommu *iommu; int devid = -1; + if (!amd_iommu_irq_remap) + return 0; + if (x86_fwspec_is_ioapic(fwspec)) devid = get_ioapic_devid(fwspec->param[0]); else if (x86_fwspec_is_hpet(fwspec)) |