From dead723e6f049e9fb6b05e5b93456982798ea961 Mon Sep 17 00:00:00 2001 From: "Isaac J. Manjarres" Date: Mon, 25 Jan 2021 13:52:25 -0800 Subject: [PATCH] iommu/arm-smmu-qcom: Fix mask extraction for bootloader programmed SMRs When extracting the mask for a SMR that was programmed by the bootloader, the SMR's valid bit is also extracted and is treated as part of the mask, which is not correct. Consider the scenario where an SMMU master whose context is determined by a bootloader programmed SMR is removed (omitting parts of device/driver core): ->iommu_release_device() -> arm_smmu_release_device() -> arm_smmu_master_free_smes() -> arm_smmu_free_sme() /* Assume that the SME is now free */ -> arm_smmu_write_sme() -> arm_smmu_write_smr() /* Construct SMR value using mask and SID */ Since the valid bit was considered as part of the mask, the SMR will be programmed as valid. Fix the SMR mask extraction step for bootloader programmed SMRs by masking out the valid bit when we know that we're already working with a valid SMR. Fixes: 07a7f2caaa5a ("iommu/arm-smmu-qcom: Read back stream mappings") Signed-off-by: Isaac J. Manjarres Cc: stable@vger.kernel.org Reviewed-by: Robin Murphy Link: https://lore.kernel.org/r/1611611545-19055-1-git-send-email-isaacm@codeaurora.org Signed-off-by: Will Deacon --- drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c index 3b6fdbb6c9168..98b3a1c2a1813 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c @@ -207,6 +207,8 @@ static int qcom_smmu_cfg_probe(struct arm_smmu_device *smmu) smr = arm_smmu_gr0_read(smmu, ARM_SMMU_GR0_SMR(i)); if (FIELD_GET(ARM_SMMU_SMR_VALID, smr)) { + /* Ignore valid bit for SMR mask extraction. */ + smr &= ~ARM_SMMU_SMR_VALID; smmu->smrs[i].id = FIELD_GET(ARM_SMMU_SMR_ID, smr); smmu->smrs[i].mask = FIELD_GET(ARM_SMMU_SMR_MASK, smr); smmu->smrs[i].valid = true; -- 2.30.2