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| author | Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> | 2017-02-27 15:30:26 +0300 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2017-03-10 21:23:34 +0300 |
| commit | a03849e7210277fa212779b7cd9c30e1ab6194b2 (patch) | |
| tree | c4cbc53783a84410cd143a758202240bebed845c /drivers/iommu/io-pgtable-arm-v7s.c | |
| parent | ed46e66cc1b3d684042f92dfa2ab15ee917b4cac (diff) | |
| download | linux-a03849e7210277fa212779b7cd9c30e1ab6194b2.tar.xz | |
iommu/io-pgtable-arm-v7s: Check for leaf entry before dereferencing it
Do a check for already installed leaf entry at the current level before
dereferencing it in order to avoid walking the page table down with
wrong pointer to the next level.
Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
CC: Will Deacon <will.deacon@arm.com>
CC: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'drivers/iommu/io-pgtable-arm-v7s.c')
| -rw-r--r-- | drivers/iommu/io-pgtable-arm-v7s.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c index 1c049e2e12bf..8d6ca28c3e1f 100644 --- a/drivers/iommu/io-pgtable-arm-v7s.c +++ b/drivers/iommu/io-pgtable-arm-v7s.c @@ -422,8 +422,12 @@ static int __arm_v7s_map(struct arm_v7s_io_pgtable *data, unsigned long iova, pte |= ARM_V7S_ATTR_NS_TABLE; __arm_v7s_set_pte(ptep, pte, 1, cfg); - } else { + } else if (ARM_V7S_PTE_IS_TABLE(pte, lvl)) { cptep = iopte_deref(pte, lvl); + } else { + /* We require an unmap first */ + WARN_ON(!selftest_running); + return -EEXIST; } /* Rinse, repeat */ |