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Subject[PATCH 1/3] iommu/arm-smmu: change IOMMU_EXEC to IOMMU_NOEXEC
Date
Exposing the XN flag of the SMMU driver as IOMMU_NOEXEC instead of
IOMMU_EXEC makes it enforceable, since for IOMMUs that don't support
the XN flag pages will always be executable.

Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
Acked-by: Joerg Roedel <jroedel@suse.de>
---
drivers/iommu/arm-smmu.c | 9 +++++----
include/linux/iommu.h | 2 +-
2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 60558f7..566c176 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -1281,7 +1281,7 @@ static int arm_smmu_alloc_init_pte(struct arm_smmu_device *smmu, pmd_t *pmd,
unsigned long pfn, int prot, int stage)
{
pte_t *pte, *start;
- pteval_t pteval = ARM_SMMU_PTE_PAGE | ARM_SMMU_PTE_AF | ARM_SMMU_PTE_XN;
+ pteval_t pteval = ARM_SMMU_PTE_PAGE | ARM_SMMU_PTE_AF;

if (pmd_none(*pmd)) {
/* Allocate a new set of tables */
@@ -1315,10 +1315,11 @@ static int arm_smmu_alloc_init_pte(struct arm_smmu_device *smmu, pmd_t *pmd,
pteval |= ARM_SMMU_PTE_MEMATTR_NC;
}

+ if (prot & IOMMU_NOEXEC)
+ pteval |= ARM_SMMU_PTE_XN;
+
/* If no access, create a faulting entry to avoid TLB fills */
- if (prot & IOMMU_EXEC)
- pteval &= ~ARM_SMMU_PTE_XN;
- else if (!(prot & (IOMMU_READ | IOMMU_WRITE)))
+ if (!(prot & (IOMMU_READ | IOMMU_WRITE)))
pteval &= ~ARM_SMMU_PTE_PAGE;

pteval |= ARM_SMMU_PTE_SH_IS;
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 379a617..5f6f71c 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -27,7 +27,7 @@
#define IOMMU_READ (1 << 0)
#define IOMMU_WRITE (1 << 1)
#define IOMMU_CACHE (1 << 2) /* DMA cache coherency */
-#define IOMMU_EXEC (1 << 3)
+#define IOMMU_NOEXEC (1 << 3)

struct iommu_ops;
struct iommu_group;
--
2.1.1


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