Commit 9113785c authored Jul 27, 2015 by Russell King Committed by Thierry Reding Aug 13, 2015

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>

parent d770e558

drivers/iommu/tegra-smmu.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -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);