[PATCH 5.10 0/1] iommu/amd: Prepare for multiple DMA domain types

[PATCH 5.10 0/1] iommu/amd: Prepare for multiple DMA domain types

[Daniil Dulov]

Svacer reports possible dereference of a NULL-pointer in 
amd_iommu_probe_finalize(). The problem is present in 5.10 stable release
and can be fixed by the following upstream patch. In order to apply this
patch, the incoming changes had to be manually accepted. This action was
necessary due to some differences in the code of amd_iommu_probe_finalize()
of the upstream version and 5.10 version of the kernel.

[PATCH 5.10 1/1] iommu/amd: Prepare for multiple DMA domain types

[Daniil Dulov]

From: Robin Murphy <robin.murphy@arm.com>

commit 6d596039392bac2a0160fb71300d314943411e2a  upstream.

The DMA ops reset/setup can simply be unconditional, since
iommu-dma already knows only to touch DMA domains.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/6450b4f39a5a086d505297b4a53ff1e4a7a0fe7c.1628682049.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Daniil Dulov <d.dulov@aladdin.ru>
---
 drivers/iommu/amd/iommu.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 0a061a196b53..16a1c2a44bce 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -2257,12 +2257,9 @@ static struct iommu_device *amd_iommu_probe_device(struct device *dev)
 
 static void amd_iommu_probe_finalize(struct device *dev)
 {
-	struct iommu_domain *domain;
-
 	/* Domains are initialized for this device - have a look what we ended up with */
-	domain = iommu_get_domain_for_dev(dev);
-	if (domain->type == IOMMU_DOMAIN_DMA)
-		iommu_setup_dma_ops(dev, IOVA_START_PFN << PAGE_SHIFT, 0);
+	set_dma_ops(dev, NULL);
+	iommu_setup_dma_ops(dev, 0, U64_MAX);
 }
 
 static void amd_iommu_release_device(struct device *dev)
-- 
2.25.1

Re: [PATCH 5.10 1/1] iommu/amd: Prepare for multiple DMA domain types

[kernel test robot]

Hi,

Thanks for your patch.

FYI: kernel test robot notices the stable kernel rule is not satisfied.

The check is based on https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html#option-3

Rule: The upstream commit ID must be specified with a separate line above the commit text.
Subject: [PATCH 5.10 1/1] iommu/amd: Prepare for multiple DMA domain types
Link: https://lore.kernel.org/stable/20241018095122.437330-2-d.dulov%40aladdin.ru

Please ignore this mail if the patch is not relevant for upstream.

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