[PATCH 2/2] asm-generic: add an optional pfn_valid check to pfn_valid
Christoph Hellwig <[email protected]>
| Newsgroups | gmane.linux.ports.ppc64.devel,gmane.linux.ports.alpha,gmane.linux.kernel,gmane.linux.kernel.arc,gmane.linux.ports.arm.kernel,gmane.linux.ports.hexagon,gmane.linux.ports.mips,gmane.linux.ports.parisc,gmane.linux.ports.riscv,gmane.linux.ports.sh.devel,gmane.linux.ports.sparc,gmane.linux.uml.devel,gmane.linux.kernel.cross-arch |
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| Message-ID | <[email protected]> |
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 <[email protected]> --- 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