From a8258ffed2efdf533bdc756141eeb7bc5301ad4f Mon Sep 17 00:00:00 2001 From: Mostafa Saleh Date: Fri, 9 Jan 2026 17:18:05 +0000 Subject: iommu: debug-pagealloc: Check mapped/unmapped kernel memory MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Now, as the page_ext holds count of IOMMU mappings, we can use it to assert that any page allocated/freed is indeed not in the IOMMU. The sanitizer doesn’t protect against mapping/unmapping during this period. However, that’s less harmful as the page is not used by the kernel. Reviewed-by: Samiullah Khawaja Reviewed-by: Lu Baolu Signed-off-by: Mostafa Saleh Reviewed-by: Pranjal Shrivastava Signed-off-by: Joerg Roedel --- include/linux/iommu-debug-pagealloc.h | 14 ++++++++++++++ include/linux/mm.h | 5 +++++ 2 files changed, 19 insertions(+) (limited to 'include/linux') diff --git a/include/linux/iommu-debug-pagealloc.h b/include/linux/iommu-debug-pagealloc.h index a439d6815ca1..46c3c1f70150 100644 --- a/include/linux/iommu-debug-pagealloc.h +++ b/include/linux/iommu-debug-pagealloc.h @@ -13,6 +13,20 @@ DECLARE_STATIC_KEY_FALSE(iommu_debug_initialized); extern struct page_ext_operations page_iommu_debug_ops; +void __iommu_debug_check_unmapped(const struct page *page, int numpages); + +static inline void iommu_debug_check_unmapped(const struct page *page, int numpages) +{ + if (static_branch_unlikely(&iommu_debug_initialized)) + __iommu_debug_check_unmapped(page, numpages); +} + +#else +static inline void iommu_debug_check_unmapped(const struct page *page, + int numpages) +{ +} + #endif /* CONFIG_IOMMU_DEBUG_PAGEALLOC */ #endif /* __LINUX_IOMMU_DEBUG_PAGEALLOC_H */ diff --git a/include/linux/mm.h b/include/linux/mm.h index 6f959d8ca4b4..32205d2a24b2 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -36,6 +36,7 @@ #include #include #include +#include struct mempolicy; struct anon_vma; @@ -4133,12 +4134,16 @@ extern void __kernel_map_pages(struct page *page, int numpages, int enable); #ifdef CONFIG_DEBUG_PAGEALLOC static inline void debug_pagealloc_map_pages(struct page *page, int numpages) { + iommu_debug_check_unmapped(page, numpages); + if (debug_pagealloc_enabled_static()) __kernel_map_pages(page, numpages, 1); } static inline void debug_pagealloc_unmap_pages(struct page *page, int numpages) { + iommu_debug_check_unmapped(page, numpages); + if (debug_pagealloc_enabled_static()) __kernel_map_pages(page, numpages, 0); } -- cgit v1.2.3