From 3e25d5a49f99b75be2c6cfb165e4f77dc6d739a2 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 23 Oct 2024 07:36:37 +0200 Subject: [PATCH] asm-generic: add an optional pfn_valid check to page_to_phys page_to_pfn is usually implemented by pointer arithmetics on the memory map, which means that bogus input can lead to even more bogus output. Powerpc had a pfn_valid check on the intermediate pfn in the page_to_phys implementation when CONFIG_DEBUG_VIRTUAL is defined, which seems generally useful, so add that to the generic version. Signed-off-by: Christoph Hellwig Reviewed-by: Thomas Huth Signed-off-by: Arnd Bergmann --- include/asm-generic/memory_model.h | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/include/asm-generic/memory_model.h b/include/asm-generic/memory_model.h index a73a140cbecd..6d1fb6162ac1 100644 --- a/include/asm-generic/memory_model.h +++ b/include/asm-generic/memory_model.h @@ -64,7 +64,17 @@ static inline int pfn_valid(unsigned long pfn) #define page_to_pfn __page_to_pfn #define pfn_to_page __pfn_to_page +#ifdef CONFIG_DEBUG_VIRTUAL +#define page_to_phys(page) \ +({ \ + unsigned long __pfn = page_to_pfn(page); \ + \ + WARN_ON_ONCE(!pfn_valid(__pfn)); \ + PFN_PHYS(__pfn); \ +}) +#else #define page_to_phys(page) PFN_PHYS(page_to_pfn(page)) +#endif /* CONFIG_DEBUG_VIRTUAL */ #define phys_to_page(phys) pfn_to_page(PHYS_PFN(phys)) #endif /* __ASSEMBLY__ */