[RFC PATCH v6 01/20] iommu/arm-smmu: change IOMMU_EXEC to IOMMU_NOEXEC

Antonios Motakis a.motakis at virtualopensystems.com
Thu Jun 5 10:03:09 PDT 2014


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 at virtualopensystems.com>
---
 drivers/iommu/arm-smmu.c | 2 +-
 include/linux/iommu.h    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 647c3c7..d5a2200 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -1294,7 +1294,7 @@ static int arm_smmu_alloc_init_pte(struct arm_smmu_device *smmu, pmd_t *pmd,
 	}
 
 	/* If no access, create a faulting entry to avoid TLB fills */
-	if (prot & IOMMU_EXEC)
+	if (!(prot & IOMMU_NOEXEC))
 		pteval &= ~ARM_SMMU_PTE_XN;
 	else if (!(prot & (IOMMU_READ | IOMMU_WRITE)))
 		pteval &= ~ARM_SMMU_PTE_PAGE;
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index b96a5b2..fc464d2 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;
-- 
1.8.3.2




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