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authorRussell King <rmk+kernel@arm.linux.org.uk>2015-07-27 13:29:00 +0100
committerThierry Reding <treding@nvidia.com>2015-08-13 16:06:36 +0200
commit9113785c3e918187b6b0c084c60e0344a2f1685c (patch)
tree7e22a7c742ca5cab5524fa2fabae496a4a6950fd /drivers/iommu
parentd770e558e21961ad6cfdf0ff7df0eb5d7d4f0754 (diff)
iommu/tegra-smmu: Fix iova_to_phys() method
iova_to_phys() has several problems: (a) iova_to_phys() is supposed to return 0 if there is no entry present for the iova. (b) if as_get_pte() fails, we oops the kernel by dereferencing a NULL pointer. Really, we should not even be trying to allocate a page table at all, but should only be returning the presence of the 2nd level page table. This will be fixed in a subsequent patch. Treat both of these conditions as "no mapping" conditions. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Thierry Reding <treding@nvidia.com>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/tegra-smmu.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index c1f2e521dc52..083354903a1a 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -592,6 +592,9 @@ static phys_addr_t tegra_smmu_iova_to_phys(struct iommu_domain *domain,
u32 *pte;
pte = as_get_pte(as, iova, &page);
+ if (!pte || !*pte)
+ return 0;
+
pfn = *pte & as->smmu->pfn_mask;
return PFN_PHYS(pfn);