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3e25d5a49f
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>
82 lines
2 KiB
C
82 lines
2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __ASM_MEMORY_MODEL_H
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#define __ASM_MEMORY_MODEL_H
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#include <linux/pfn.h>
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#ifndef __ASSEMBLY__
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/*
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* supports 3 memory models.
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*/
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#if defined(CONFIG_FLATMEM)
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#ifndef ARCH_PFN_OFFSET
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#define ARCH_PFN_OFFSET (0UL)
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#endif
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#define __pfn_to_page(pfn) (mem_map + ((pfn) - ARCH_PFN_OFFSET))
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#define __page_to_pfn(page) ((unsigned long)((page) - mem_map) + \
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ARCH_PFN_OFFSET)
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#ifndef pfn_valid
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static inline int pfn_valid(unsigned long pfn)
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{
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/* avoid <linux/mm.h> include hell */
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extern unsigned long max_mapnr;
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unsigned long pfn_offset = ARCH_PFN_OFFSET;
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return pfn >= pfn_offset && (pfn - pfn_offset) < max_mapnr;
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}
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#define pfn_valid pfn_valid
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#endif
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#elif defined(CONFIG_SPARSEMEM_VMEMMAP)
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/* memmap is virtually contiguous. */
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#define __pfn_to_page(pfn) (vmemmap + (pfn))
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#define __page_to_pfn(page) (unsigned long)((page) - vmemmap)
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#elif defined(CONFIG_SPARSEMEM)
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/*
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* Note: section's mem_map is encoded to reflect its start_pfn.
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* section[i].section_mem_map == mem_map's address - start_pfn;
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*/
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#define __page_to_pfn(pg) \
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({ const struct page *__pg = (pg); \
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int __sec = page_to_section(__pg); \
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(unsigned long)(__pg - __section_mem_map_addr(__nr_to_section(__sec))); \
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})
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#define __pfn_to_page(pfn) \
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({ unsigned long __pfn = (pfn); \
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struct mem_section *__sec = __pfn_to_section(__pfn); \
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__section_mem_map_addr(__sec) + __pfn; \
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})
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#endif /* CONFIG_FLATMEM/SPARSEMEM */
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/*
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* Convert a physical address to a Page Frame Number and back
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*/
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#define __phys_to_pfn(paddr) PHYS_PFN(paddr)
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#define __pfn_to_phys(pfn) PFN_PHYS(pfn)
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#define page_to_pfn __page_to_pfn
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#define pfn_to_page __pfn_to_page
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#ifdef CONFIG_DEBUG_VIRTUAL
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#define page_to_phys(page) \
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({ \
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unsigned long __pfn = page_to_pfn(page); \
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\
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WARN_ON_ONCE(!pfn_valid(__pfn)); \
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PFN_PHYS(__pfn); \
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})
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#else
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#define page_to_phys(page) PFN_PHYS(page_to_pfn(page))
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#endif /* CONFIG_DEBUG_VIRTUAL */
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#define phys_to_page(phys) pfn_to_page(PHYS_PFN(phys))
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#endif /* __ASSEMBLY__ */
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#endif
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