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asm-generic: add an optional pfn_valid check to page_to_phys

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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 <hch@lst.de>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
This commit is contained in:
Christoph Hellwig 2024-10-23 07:36:37 +02:00 committed by Arnd Bergmann
parent c5c3238d9b
commit 3e25d5a49f
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1 changed files with 10 additions and 0 deletions
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10
include/asm-generic/memory_model.h
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@ -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__ */