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. Signed-off-by: Mostafa Saleh --- drivers/iommu/iommu-debug.c | 22 ++++++++++++++++++++++ include/linux/iommu-debug.h | 1 + include/linux/mm.h | 7 +++++++ 3 files changed, 30 insertions(+) diff --git a/drivers/iommu/iommu-debug.c b/drivers/iommu/iommu-debug.c index cec8f594c7fa..09157fef697e 100644 --- a/drivers/iommu/iommu-debug.c +++ b/drivers/iommu/iommu-debug.c @@ -71,6 +71,28 @@ static size_t iommu_debug_page_size(struct iommu_domain *domain) return 1UL << __ffs(domain->pgsize_bitmap); } +static unsigned int iommu_debug_page_count(unsigned long phys) +{ + unsigned int ref; + struct page_ext *page_ext = get_iommu_page_ext(phys); + struct iommu_debug_metadate *d = get_iommu_data(page_ext); + + ref = atomic_read(&d->ref); + page_ext_put(page_ext); + return ref; +} + +void iommu_debug_check_unmapped(const struct page *page, int numpages) +{ + if (!static_branch_likely(&iommu_debug_initialized)) + return; + + while (numpages--) { + WARN_ON(iommu_debug_page_count(page_to_phys(page))); + page++; + } +} + void iommu_debug_map(struct iommu_domain *domain, phys_addr_t phys, size_t size) { size_t off; diff --git a/include/linux/iommu-debug.h b/include/linux/iommu-debug.h index 8d3ea661660f..aaf893cfafd0 100644 --- a/include/linux/iommu-debug.h +++ b/include/linux/iommu-debug.h @@ -17,6 +17,7 @@ void iommu_debug_map(struct iommu_domain *domain, phys_addr_t phys, size_t size) void iommu_debug_unmap(struct iommu_domain *domain, unsigned long iova, size_t size); void iommu_debug_remap(struct iommu_domain *domain, unsigned long iova, size_t size); void iommu_debug_init(void); +void iommu_debug_check_unmapped(const struct page *page, int numpages); #endif /* CONFIG_IOMMU_DEBUG_PAGEALLOC */ diff --git a/include/linux/mm.h b/include/linux/mm.h index 06978b4dbeb8..00f5de44faa0 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -36,6 +36,7 @@ #include #include #include +#include struct mempolicy; struct anon_vma; @@ -3806,12 +3807,18 @@ 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) { +#ifdef CONFIG_IOMMU_DEBUG_PAGEALLOC + iommu_debug_check_unmapped(page, numpages); +#endif if (debug_pagealloc_enabled_static()) __kernel_map_pages(page, numpages, 1); } static inline void debug_pagealloc_unmap_pages(struct page *page, int numpages) { +#ifdef CONFIG_IOMMU_DEBUG_PAGEALLOC + iommu_debug_check_unmapped(page, numpages); +#endif if (debug_pagealloc_enabled_static()) __kernel_map_pages(page, numpages, 0); } -- 2.51.0.618.g983fd99d29-goog