[PATCH 6/8] dma-mapping: fail early if physical address is mapped through platform callback
From: Leon Romanovsky <leon@kernel.org>
Date: 2025-06-25 13:19:38
Also in:
linux-iommu, linux-mm, linux-trace-kernel, linuxppc-dev, lkml, virtualization
Subsystem:
dma mapping helpers, the rest · Maintainers:
Marek Szyprowski, Linus Torvalds
From: Leon Romanovsky <leonro@nvidia.com> All platforms which implement map_page interface don't support physical addresses without real struct page. Add condition to check it. Signed-off-by: Leon Romanovsky <leonro@nvidia.com> --- kernel/dma/mapping.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index 709405d46b2b..74efb6909103 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c@@ -158,6 +158,7 @@ dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page, { const struct dma_map_ops *ops = get_dma_ops(dev); phys_addr_t phys = page_to_phys(page) + offset; + bool is_pfn_valid = true; dma_addr_t addr; BUG_ON(!valid_dma_direction(dir));
@@ -170,8 +171,20 @@ dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page, addr = dma_direct_map_phys(dev, phys, size, dir, attrs); else if (use_dma_iommu(dev)) addr = iommu_dma_map_phys(dev, phys, size, dir, attrs); - else + else { + if (IS_ENABLED(CONFIG_DMA_API_DEBUG)) + is_pfn_valid = pfn_valid(PHYS_PFN(phys)); + + if (unlikely(!is_pfn_valid)) + return DMA_MAPPING_ERROR; + + /* + * All platforms which implement .map_page() don't support + * non-struct page backed addresses. + */ addr = ops->map_page(dev, page, offset, size, dir, attrs); + } + kmsan_handle_dma(phys, size, dir); trace_dma_map_phys(dev, phys, addr, size, dir, attrs); debug_dma_map_phys(dev, phys, size, dir, addr, attrs);
--
2.49.0