From: "Isaac J. Manjarres" <isaacm@codeaurora.org> To: will@kernel.org, robin.murphy@arm.com, joro@8bytes.org, bjorn.andersson@linaro.org Cc: "Isaac J. Manjarres" <isaacm@codeaurora.org>, linux-arm-kernel@lists.infradead.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH] iommu/arm-smmu-qcom: Fix mask extraction for bootloader programmed SMRs Date: Mon, 25 Jan 2021 13:52:25 -0800 [thread overview] Message-ID: <1611611545-19055-1-git-send-email-isaacm@codeaurora.org> (raw) 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 <isaacm@codeaurora.org> Cc: stable@vger.kernel.org --- 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 bcda170..abb1d2f 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c @@ -206,6 +206,8 @@ 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; -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project
WARNING: multiple messages have this Message-ID (diff)
From: "Isaac J. Manjarres" <isaacm@codeaurora.org> To: will@kernel.org, robin.murphy@arm.com, joro@8bytes.org, bjorn.andersson@linaro.org Cc: "Isaac J. Manjarres" <isaacm@codeaurora.org>, stable@vger.kernel.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH] iommu/arm-smmu-qcom: Fix mask extraction for bootloader programmed SMRs Date: Mon, 25 Jan 2021 13:52:25 -0800 [thread overview] Message-ID: <1611611545-19055-1-git-send-email-isaacm@codeaurora.org> (raw) 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 <isaacm@codeaurora.org> Cc: stable@vger.kernel.org --- 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 bcda170..abb1d2f 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c @@ -206,6 +206,8 @@ 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; -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
next reply other threads:[~2021-01-25 21:54 UTC|newest] Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-01-25 21:52 Isaac J. Manjarres [this message] 2021-01-25 21:52 ` [PATCH] iommu/arm-smmu-qcom: Fix mask extraction for bootloader programmed SMRs Isaac J. Manjarres 2021-01-26 10:34 ` Robin Murphy 2021-01-26 10:34 ` Robin Murphy 2021-01-26 10:34 ` Robin Murphy 2021-01-26 22:35 ` Will Deacon 2021-01-26 22:35 ` Will Deacon 2021-01-26 22:35 ` Will Deacon
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