kernel/linux.git/drivers/iommu, branch v7.0.12

iommu, debugobjects: avoid gcc-16.1 section mismatch warnings

2026-06-09T10:32:39+00:00

commit 4c9ad387aa2d6785299722e54224d34764edaeb3 upstream. gcc-16 has gained some more advanced inter-procedual optimization techniques that enable it to inline the dummy_tlb_add_page() and dummy_tlb_flush() function pointers into a specialized version of __arm_v7s_unmap: WARNING: modpost: vmlinux: section mismatch in reference: __arm_v7s_unmap+0x2cc (section: .text) -> dummy_tlb_add_page (section: .init.text) ERROR: modpost: Section mismatches detected. >From what I can tell, the transformation is correct, as this is only called when __arm_v7s_unmap() is called from arm_v7s_do_selftests(), which is also __init. Since __arm_v7s_unmap() however is not __init, gcc cannot inline the inner function calls directly. In debug_objects_selftest(), the same thing happens. Both the caller and the leaf function are __init, but the IPA pulls it into a non-init one: WARNING: modpost: vmlinux: section mismatch in reference: lookup_object_or_alloc+0x7c (section: .text.lookup_object_or_alloc) -> is_static_object (section: .init.text) Marking the affected functions as not "__init" would reliably avoid this issue but is not a good solution because it removes an otherwise correct annotation. I tried marking the functions as 'noinline', but that ended up not covering all the affected configurations. With some more experimenting, I found that marking these functions as __attribute__((noipa)) is both logical and reliable. In order to keep the syntax readable, add a custom macro for this in include/linux/compiler_attributes.h next to other related macros and use it to annotate both files. Link: https://lore.kernel.org/all/abRB6g-48ZX6Yl2r@willie-the-truck/ Cc: Will Deacon Cc: Thomas Gleixner Cc: Andrew Morton Cc: Miguel Ojeda Cc: linux-kbuild@vger.kernel.org Cc: stable@vger.kernel.org Signed-off-by: Arnd Bergmann Acked-by: Will Deacon Acked-by: Thomas Gleixner Acked-by: Miguel Ojeda Signed-off-by: Joerg Roedel Signed-off-by: Greg Kroah-Hartman

iommupt: Fix the end_index calculation in __map_range_leaf()

2026-06-01T15:54:45+00:00

[ Upstream commit 58829512ad461af8f35941069c209941e3a97b65 ] Sashiko noticed a mismatch of units in this math: num_leaves is actually the number of leaf *entries* (so a 16-item contiguous leaf is one num_leaves), while index is in items. The mismatch in maths causes __map_range_leaf() to exit early instead of efficiently filling a larger range of contiguous PTEs. The early exit is caught by the functions above and then __map_range_leaf() is re-invoked, so there is no functional issue. Correct the misuse of units by adjusting num_leaves with the leaf size and avoid the performance cost of looping externally. There are also some mismatched types for num_leaves; simplify things to remove the duplicated calculations. Fixes: d6c65b0fd621 ("iommupt: Avoid rewalking during map") Signed-off-by: Jason Gunthorpe Reviewed-by: Samiullah Khawaja Reviewd-by: Pranjal Shrivastava Tested-by: Josua Mayer Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin

iommupt: Check for missing PAGE_SIZE in the pgsize_bitmap

2026-06-01T15:54:45+00:00

[ Upstream commit 8ef3f77c440005c7f04229a75976bfc078364247 ] Sashiko pointed out that the driver could drop PAGE_SIZE from the pgsize_bitmap. That is technically allowed but nothing does it, and such an iommu_domain would not be used with the DMA API today. Still, it is against the design and it is trivial to fix up. Lift the PT_WARN_ON to the if branch and just skip the fast path. Fixes: dcd6a011a8d5 ("iommupt: Add map_pages op") Signed-off-by: Jason Gunthorpe Reviewed-by: Pranjal Shrivastava Reviewed-by: Samiullah Khawaja Tested-by: Josua Mayer Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin

iommu: Handle unmap error when iommu_debug is enabled

2026-06-01T15:54:45+00:00

[ Upstream commit 0735c54804c709d1b292f3b6947cfb560b2ce552 ] Sashiko noticed a latent bug where the map error flow called iommu_unmap() which calls iommu_debug_unmap_begin()/iommu_debug_unmap_end() however since this is an error path the map flow never actually established the original iommu_debug_map() it will malfunction. Lift the unmap error handling into iommu_map_nosync() and reorder it so the trace_map()/iommu_debug_map() records the partial mapping and then immediately unmaps it. This avoid creating the unbalanced tracking and provides saner tracing instead of a unmap unmatched to any map. Fixes: ccc21213f013 ("iommu: Add calls for IOMMU_DEBUG_PAGEALLOC") Signed-off-by: Jason Gunthorpe Reviewed-by: Pranjal Shrivastava Reviewed-by: Samiullah Khawaja Reviewed-by: Mostafa Saleh Tested-by: Josua Mayer Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin

iommu: Fix up map/unmap debugging for iommupt domains

2026-06-01T15:54:45+00:00

[ Upstream commit b948a87228482235afbaf5f4d8037860b5c470fd ] Sashiko noticed a few issues in this path, and a few more were found on review. Tidy them up further. These are intertwined because the debug code depends on some of the WARN_ONs to function right: Lift into iommu_map_nosync(): - The might_sleep_if() - 0 pgsize_bitmap WARN_ON - Promote the illegal domain->type to a WARN_ON - WARN_ON for illegal gfp flags Then remove the return 0 since it is now safe to call iommu_debug_map(). Lift into __iommu_unmap(): - 0 pgsize_bitmap WARN_ON - Promote the illegal domain->type to a WARN_ON - iommu_debug_unmap_begin() This now pairs with the unconditional iommu_debug_map() on the mapping side. Thus iommu debugging now works for iommupt along with some of the other debugging features. Fixes: 99fb8afa16ad ("iommupt: Directly call iommupt's unmap_range()") Fixes: d6c65b0fd621 ("iommupt: Avoid rewalking during map") Signed-off-by: Jason Gunthorpe Reviewed-by: Pranjal Shrivastava Reviewed-by: Samiullah Khawaja Reviewed-by: Mostafa Saleh Tested-by: Josua Mayer Signed-off-by: Joerg Roedel Stable-dep-of: 0735c54804c7 ("iommu: Handle unmap error when iommu_debug is enabled") Signed-off-by: Sasha Levin

iommu: Fix loss of errno on map failure for classic ops

2026-06-01T15:54:44+00:00

[ Upstream commit 6fc7e8a3b8115294f60f5c89de27330bf1b9c98e ] A typo, likely from a rebase, inverted the condition and caused errors to be lost. Fix it to be "if (ret)". This was breaking iommu_create_device_direct_mappings() on drivers that don't use iommupt and don't fully set up their domain in alloc_pages() (i.e., SMMUv2). In this case the first call of iommu_create_device_direct_mappings() should fail due to the incompletely initialized domain. Since it wrongly returns success, the second call to iommu_create_device_direct_mappings() doesn't happen and IOMMU_RESV_DIRECT is never set up. Cc: stable@vger.kernel.org Fixes: d6c65b0fd621 ("iommupt: Avoid rewalking during map") Reported-by: Josua Mayer Closes: https://lore.kernel.org/all/321c2e57-6a17-4aef-ba42-d2ebd577e472@solid-run.com/ Signed-off-by: Jason Gunthorpe Reviewed-by: Pranjal Shrivastava Reviewed-by: Samiullah Khawaja Reviewed-by: Mostafa Saleh Tested-by: Josua Mayer Signed-off-by: Joerg Roedel Stable-dep-of: 0735c54804c7 ("iommu: Handle unmap error when iommu_debug is enabled") Signed-off-by: Sasha Levin

iommupt: Avoid rewalking during map

2026-06-01T15:54:44+00:00

[ Upstream commit d6c65b0fd6218bd21ed0be7a8d3218e8f6dc91de ] Currently the core code provides a simplified interface to drivers where it fragments a requested multi-page map into single page size steps after doing all the calculations to figure out what page size is appropriate. Each step rewalks the page tables from the start. Since iommupt has a single implementation of the mapping algorithm it can internally compute each step as it goes while retaining its current position in the walk. Add a new function pt_pgsz_count() which computes the same page size fragement of a large mapping operations. Compute the next fragment when all the leaf entries of the current fragement have been written, then continue walking from the current point. The function pointer is run through pt_iommu_ops instead of iommu_domain_ops to discourage using it outside iommupt. All drivers with their own page tables should continue to use the simplified map_pages() style interfaces. Reviewed-by: Samiullah Khawaja Reviewed-by: Kevin Tian Signed-off-by: Jason Gunthorpe Reviewed-by: Lu Baolu Signed-off-by: Joerg Roedel Stable-dep-of: 0735c54804c7 ("iommu: Handle unmap error when iommu_debug is enabled") Signed-off-by: Sasha Levin

iommupt: Directly call iommupt's unmap_range()

2026-06-01T15:54:44+00:00

[ Upstream commit 99fb8afa16add85ed016baee9735231bca0c32b4 ] The common algorithm in iommupt does not require the iommu_pgsize() calculations, it can directly unmap any arbitrary range. Add a new function pointer to directly call an iommupt unmap_range op and make __iommu_unmap() call it directly. Gives about a 5% gain on single page unmappings. The function pointer is run through pt_iommu_ops instead of iommu_domain_ops to discourage using it outside iommupt. All drivers with their own page tables should continue to use the simplified map/unmap_pages() style interfaces. Reviewed-by: Samiullah Khawaja Reviewed-by: Kevin Tian Signed-off-by: Jason Gunthorpe Reviewed-by: Lu Baolu Signed-off-by: Joerg Roedel Stable-dep-of: 0735c54804c7 ("iommu: Handle unmap error when iommu_debug is enabled") Signed-off-by: Sasha Levin

iommu/amd: Remove latent out-of-bounds access in IOMMU debugfs

2026-06-01T15:54:19+00:00

[ Upstream commit 8dfd3d8d74435344ee8dc9237596959c8b2a6cbe ] In iommu_mmio_write() and iommu_capability_write(), the variables dbg_mmio_offset and dbg_cap_offset are declared as int. However, they are populated using kstrtou32_from_user(). If a user provides a sufficiently large value, it can become a negative integer. Prior to this patch, the AMD IOMMU debugfs implementation was already protected by different mechanisms. 1. #define OFS_IN_SZ 8 ensures the user string <= 8 bytes, so e.g. 0xffffffff isn't a valid input. if (cnt > OFS_IN_SZ) return -EINVAL; 2. Implicit type promotion in iommu_mmio_write(), dbg_mmio_offset is int and iommu->mmio_phys_end is u64 if (dbg_mmio_offset > iommu->mmio_phys_end - sizeof(u64)) return -EINVAL; 3. The show handlers would currently catch the negative number and refuse to perform the read. Replace kstrtou32_from_user() with kstrtos32_from_user() to parse the input, and check for negative values to explicitly prevent out-of-bounds memory accesses directly in iommu_mmio_write() and iommu_capability_write(). Signed-off-by: Eder Zulian Fixes: 7a4ee419e8c1 ("iommu/amd: Add debugfs support to dump IOMMU MMIO registers") Cc: stable@vger.kernel.org Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin

iommu/amd: Fix illegal cap/mmio access in IOMMU debugfs

2026-06-01T15:54:19+00:00

[ Upstream commit 0e59645683b7b6fa20eceb21a6f420e4f7412943 ] In the current AMD IOMMU debugfs, when multiple processes simultaneously access the IOMMU mmio/cap registers using the IOMMU debugfs, illegal access issues can occur in the following execution flow: 1. CPU1: Sets a valid access address using iommu_mmio/capability_write, and verifies the access address's validity in iommu_mmio/capability_show 2. CPU2: Sets an invalid address using iommu_mmio/capability_write 3. CPU1: accesses the IOMMU mmio/cap registers based on the invalid address, resulting in an illegal access. This patch modifies the execution process to first verify the address's validity and then access it based on the same address, ensuring correctness and robustness. Signed-off-by: Guanghui Feng Signed-off-by: Joerg Roedel Stable-dep-of: 8dfd3d8d7443 ("iommu/amd: Remove latent out-of-bounds access in IOMMU debugfs") Signed-off-by: Sasha Levin