/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ #ifndef _LINUX_SECRETMEM_H #define _LINUX_SECRETMEM_H #ifdef CONFIG_SECRETMEM extern const struct address_space_operations secretmem_aops; static inline bool page_is_secretmem(struct page *page) { struct address_space *mapping; /* * Using page_mapping() is quite slow because of the actual call * instruction and repeated compound_head(page) inside the * page_mapping() function. * We know that secretmem pages are not compound and LRU so we can * save a couple of cycles here. */ if (PageCompound(page) || !PageLRU(page)) return false; mapping = (struct address_space *) ((unsigned long)page->mapping & ~PAGE_MAPPING_FLAGS); if (!mapping || mapping != page->mapping) return false; return mapping->a_ops == &secretmem_aops; } bool vma_is_secretmem(struct vm_area_struct *vma); bool secretmem_active(void); #else static inline bool vma_is_secretmem(struct vm_area_struct *vma) { return false; } static inline bool page_is_secretmem(struct page *page) { return false; } static inline bool secretmem_active(void) { return false; } #endif /* CONFIG_SECRETMEM */ #endif /* _LINUX_SECRETMEM_H */