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Commit a720b41c authored by Antonios Motakis's avatar Antonios Motakis Committed by Will Deacon
Browse files

iommu/arm-smmu: change IOMMU_EXEC to IOMMU_NOEXEC 



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: default avatarAntonios Motakis <a.motakis@virtualopensystems.com>
Acked-by: default avatarJoerg Roedel <jroedel@suse.de>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent f114040e

drivers/iommu/arm-smmu.c

+5 −4
Original line number Diff line number Diff line
@@ -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;

include/linux/iommu.h

+1 −1
Original line number Diff line number Diff line
@@ -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;