From: Vladimir Oltean Date: Thu, 15 Dec 2022 14:12:51 +0000 (+0200) Subject: iommu/arm-smmu-v3: Don't unregister on shutdown X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=32ea2c57dc216b6ad8125fa680d31daa5d421c95;p=linux.git iommu/arm-smmu-v3: Don't unregister on shutdown Similar to SMMUv2, this driver calls iommu_device_unregister() from the shutdown path, which removes the IOMMU groups with no coordination whatsoever with their users - shutdown methods are optional in device drivers. This can lead to NULL pointer dereferences in those drivers' DMA API calls, or worse. Instead of calling the full arm_smmu_device_remove() from arm_smmu_device_shutdown(), let's pick only the relevant function call - arm_smmu_device_disable() - more or less the reverse of arm_smmu_device_reset() - and call just that from the shutdown path. Fixes: 57365a04c921 ("iommu: Move bus setup to IOMMU device registration") Suggested-by: Robin Murphy Signed-off-by: Vladimir Oltean Link: https://lore.kernel.org/r/20221215141251.3688780-2-vladimir.oltean@nxp.com Signed-off-by: Will Deacon --- diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c index ab160198edd6b..f2425b0f0cd62 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -3858,7 +3858,9 @@ static int arm_smmu_device_remove(struct platform_device *pdev) static void arm_smmu_device_shutdown(struct platform_device *pdev) { - arm_smmu_device_remove(pdev); + struct arm_smmu_device *smmu = platform_get_drvdata(pdev); + + arm_smmu_device_disable(smmu); } static const struct of_device_id arm_smmu_of_match[] = {