[PATCH 2/2] asm-generic: add an optional pfn_valid check to pfn_valid
From: Christoph Hellwig <hch@lst.de>
Date: 2024-10-14 14:45:21
Also in:
linux-alpha, linux-arch, linux-arm-kernel, linux-m68k, linux-mips, linux-riscv, linux-s390, linux-sh, linux-um, lkml, loongarch, sparclinux
Subsystem:
generic include/asm header files, the rest · Maintainers:
Arnd Bergmann, Linus Torvalds
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 regult to it's 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 <hch@lst.de> --- 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 a73a140cbecdd7..6d1fb6162ac1a6 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__ */
--
2.45.2