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authorOleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>2017-02-27 14:30:26 +0200
committerWill Deacon <will.deacon@arm.com>2017-03-10 18:23:34 +0000
commita03849e7210277fa212779b7cd9c30e1ab6194b2 (patch)
treec4cbc53783a84410cd143a758202240bebed845c /drivers/iommu
parented46e66cc1b3d684042f92dfa2ab15ee917b4cac (diff)
downloadlinux-a03849e7210277fa212779b7cd9c30e1ab6194b2.tar.bz2
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')
-rw-r--r--drivers/iommu/io-pgtable-arm-v7s.c6
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 */