diff options
Diffstat (limited to 'arch/x86/include/asm/pgtable.h')
| -rw-r--r-- | arch/x86/include/asm/pgtable.h | 267 |
1 files changed, 180 insertions, 87 deletions
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index 9d077bca6a10..593f10aabd45 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -31,7 +31,8 @@ struct seq_file; void ptdump_walk_pgd_level(struct seq_file *m, struct mm_struct *mm); void ptdump_walk_pgd_level_debugfs(struct seq_file *m, struct mm_struct *mm, bool user); -void ptdump_walk_pgd_level_checkwx(void); +bool ptdump_walk_pgd_level_checkwx(void); +#define ptdump_check_wx ptdump_walk_pgd_level_checkwx void ptdump_walk_user_pgd_level_checkwx(void); /* @@ -41,10 +42,8 @@ void ptdump_walk_user_pgd_level_checkwx(void); #define pgprot_decrypted(prot) __pgprot(cc_mkdec(pgprot_val(prot))) #ifdef CONFIG_DEBUG_WX -#define debug_checkwx() ptdump_walk_pgd_level_checkwx() #define debug_checkwx_user() ptdump_walk_user_pgd_level_checkwx() #else -#define debug_checkwx() do { } while (0) #define debug_checkwx_user() do { } while (0) #endif @@ -121,6 +120,34 @@ extern pmdval_t early_pmd_flags; #define arch_end_context_switch(prev) do {} while(0) #endif /* CONFIG_PARAVIRT_XXL */ +static inline pmd_t pmd_set_flags(pmd_t pmd, pmdval_t set) +{ + pmdval_t v = native_pmd_val(pmd); + + return native_make_pmd(v | set); +} + +static inline pmd_t pmd_clear_flags(pmd_t pmd, pmdval_t clear) +{ + pmdval_t v = native_pmd_val(pmd); + + return native_make_pmd(v & ~clear); +} + +static inline pud_t pud_set_flags(pud_t pud, pudval_t set) +{ + pudval_t v = native_pud_val(pud); + + return native_make_pud(v | set); +} + +static inline pud_t pud_clear_flags(pud_t pud, pudval_t clear) +{ + pudval_t v = native_pud_val(pud); + + return native_make_pud(v & ~clear); +} + /* * The following only work if pte_present() is true. * Undefined behaviour if not.. @@ -141,6 +168,11 @@ static inline int pte_young(pte_t pte) return pte_flags(pte) & _PAGE_ACCESSED; } +static inline bool pte_decrypted(pte_t pte) +{ + return cc_mkdec(pte_val(pte)) == pte_val(pte); +} + #define pmd_dirty pmd_dirty static inline bool pmd_dirty(pmd_t pmd) { @@ -170,6 +202,13 @@ static inline int pud_young(pud_t pud) return pud_flags(pud) & _PAGE_ACCESSED; } +static inline bool pud_shstk(pud_t pud) +{ + return cpu_feature_enabled(X86_FEATURE_SHSTK) && + (pud_flags(pud) & (_PAGE_RW | _PAGE_DIRTY | _PAGE_PSE)) == + (_PAGE_DIRTY | _PAGE_PSE); +} + static inline int pte_write(pte_t pte) { /* @@ -235,6 +274,7 @@ static inline unsigned long pmd_pfn(pmd_t pmd) return (pfn & pmd_pfn_mask(pmd)) >> PAGE_SHIFT; } +#define pud_pfn pud_pfn static inline unsigned long pud_pfn(pud_t pud) { phys_addr_t pfn = pud_val(pud); @@ -252,8 +292,8 @@ static inline unsigned long pgd_pfn(pgd_t pgd) return (pgd_val(pgd) & PTE_PFN_MASK) >> PAGE_SHIFT; } -#define p4d_leaf p4d_large -static inline int p4d_large(p4d_t p4d) +#define p4d_leaf p4d_leaf +static inline bool p4d_leaf(p4d_t p4d) { /* No 512 GiB pages yet */ return 0; @@ -261,14 +301,14 @@ static inline int p4d_large(p4d_t p4d) #define pte_page(pte) pfn_to_page(pte_pfn(pte)) -#define pmd_leaf pmd_large -static inline int pmd_large(pmd_t pte) +#define pmd_leaf pmd_leaf +static inline bool pmd_leaf(pmd_t pte) { return pmd_flags(pte) & _PAGE_PSE; } #ifdef CONFIG_TRANSPARENT_HUGEPAGE -/* NOTE: when predicate huge page, consider also pmd_devmap, or use pmd_large */ +/* NOTE: when predicate huge page, consider also pmd_devmap, or use pmd_leaf */ static inline int pmd_trans_huge(pmd_t pmd) { return (pmd_val(pmd) & (_PAGE_PSE|_PAGE_DEVMAP)) == _PAGE_PSE; @@ -305,6 +345,30 @@ static inline int pud_devmap(pud_t pud) } #endif +#ifdef CONFIG_ARCH_SUPPORTS_PMD_PFNMAP +static inline bool pmd_special(pmd_t pmd) +{ + return pmd_flags(pmd) & _PAGE_SPECIAL; +} + +static inline pmd_t pmd_mkspecial(pmd_t pmd) +{ + return pmd_set_flags(pmd, _PAGE_SPECIAL); +} +#endif /* CONFIG_ARCH_SUPPORTS_PMD_PFNMAP */ + +#ifdef CONFIG_ARCH_SUPPORTS_PUD_PFNMAP +static inline bool pud_special(pud_t pud) +{ + return pud_flags(pud) & _PAGE_SPECIAL; +} + +static inline pud_t pud_mkspecial(pud_t pud) +{ + return pud_set_flags(pud, _PAGE_SPECIAL); +} +#endif /* CONFIG_ARCH_SUPPORTS_PUD_PFNMAP */ + static inline int pgd_devmap(pgd_t pgd) { return 0; @@ -388,23 +452,7 @@ static inline pte_t pte_wrprotect(pte_t pte) #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP static inline int pte_uffd_wp(pte_t pte) { - bool wp = pte_flags(pte) & _PAGE_UFFD_WP; - -#ifdef CONFIG_DEBUG_VM - /* - * Having write bit for wr-protect-marked present ptes is fatal, - * because it means the uffd-wp bit will be ignored and write will - * just go through. - * - * Use any chance of pgtable walking to verify this (e.g., when - * page swapped out or being migrated for all purposes). It means - * something is already wrong. Tell the admin even before the - * process crashes. We also nail it with wrong pgtable setup. - */ - WARN_ON_ONCE(wp && pte_write(pte)); -#endif - - return wp; + return pte_flags(pte) & _PAGE_UFFD_WP; } static inline pte_t pte_mkuffd_wp(pte_t pte) @@ -491,20 +539,6 @@ static inline pte_t pte_mkdevmap(pte_t pte) return pte_set_flags(pte, _PAGE_SPECIAL|_PAGE_DEVMAP); } -static inline pmd_t pmd_set_flags(pmd_t pmd, pmdval_t set) -{ - pmdval_t v = native_pmd_val(pmd); - - return native_make_pmd(v | set); -} - -static inline pmd_t pmd_clear_flags(pmd_t pmd, pmdval_t clear) -{ - pmdval_t v = native_pmd_val(pmd); - - return native_make_pmd(v & ~clear); -} - /* See comments above mksaveddirty_shift() */ static inline pmd_t pmd_mksaveddirty(pmd_t pmd) { @@ -599,20 +633,6 @@ static inline pmd_t pmd_mkwrite_novma(pmd_t pmd) pmd_t pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma); #define pmd_mkwrite pmd_mkwrite -static inline pud_t pud_set_flags(pud_t pud, pudval_t set) -{ - pudval_t v = native_pud_val(pud); - - return native_make_pud(v | set); -} - -static inline pud_t pud_clear_flags(pud_t pud, pudval_t clear) -{ - pudval_t v = native_pud_val(pud); - - return native_make_pud(v & ~clear); -} - /* See comments above mksaveddirty_shift() */ static inline pud_t pud_mksaveddirty(pud_t pud) { @@ -791,6 +811,12 @@ static inline pmd_t pmd_mkinvalid(pmd_t pmd) __pgprot(pmd_flags(pmd) & ~(_PAGE_PRESENT|_PAGE_PROTNONE))); } +static inline pud_t pud_mkinvalid(pud_t pud) +{ + return pfn_pud(pud_pfn(pud), + __pgprot(pud_flags(pud) & ~(_PAGE_PRESENT|_PAGE_PROTNONE))); +} + static inline u64 flip_protnone_guard(u64 oldval, u64 val, u64 mask); static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) @@ -838,14 +864,8 @@ static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot) pmd_result = __pmd(val); /* - * To avoid creating Write=0,Dirty=1 PMDs, pte_modify() needs to avoid: - * 1. Marking Write=0 PMDs Dirty=1 - * 2. Marking Dirty=1 PMDs Write=0 - * - * The first case cannot happen because the _PAGE_CHG_MASK will filter - * out any Dirty bit passed in newprot. Handle the second case by - * going through the mksaveddirty exercise. Only do this if the old - * value was Write=1 to avoid doing this on Shadow Stack PTEs. + * Avoid creating shadow stack PMD by accident. See comment in + * pte_modify(). */ if (oldval & _PAGE_RW) pmd_result = pmd_mksaveddirty(pmd_result); @@ -855,6 +875,29 @@ static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot) return pmd_result; } +static inline pud_t pud_modify(pud_t pud, pgprot_t newprot) +{ + pudval_t val = pud_val(pud), oldval = val; + pud_t pud_result; + + val &= _HPAGE_CHG_MASK; + val |= check_pgprot(newprot) & ~_HPAGE_CHG_MASK; + val = flip_protnone_guard(oldval, val, PHYSICAL_PUD_PAGE_MASK); + + pud_result = __pud(val); + + /* + * Avoid creating shadow stack PUD by accident. See comment in + * pte_modify(). + */ + if (oldval & _PAGE_RW) + pud_result = pud_mksaveddirty(pud_result); + else + pud_result = pud_clear_saveddirty(pud_result); + + return pud_result; +} + /* * mprotect needs to preserve PAT and encryption bits when updating * vm_page_prot @@ -909,7 +952,7 @@ static inline int is_new_memtype_allowed(u64 paddr, unsigned long size, pmd_t *populate_extra_pmd(unsigned long vaddr); pte_t *populate_extra_pte(unsigned long vaddr); -#ifdef CONFIG_PAGE_TABLE_ISOLATION +#ifdef CONFIG_MITIGATION_PAGE_TABLE_ISOLATION pgd_t __pti_set_user_pgtbl(pgd_t *pgdp, pgd_t pgd); /* @@ -923,12 +966,12 @@ static inline pgd_t pti_set_user_pgtbl(pgd_t *pgdp, pgd_t pgd) return pgd; return __pti_set_user_pgtbl(pgdp, pgd); } -#else /* CONFIG_PAGE_TABLE_ISOLATION */ +#else /* CONFIG_MITIGATION_PAGE_TABLE_ISOLATION */ static inline pgd_t pti_set_user_pgtbl(pgd_t *pgdp, pgd_t pgd) { return pgd; } -#endif /* CONFIG_PAGE_TABLE_ISOLATION */ +#endif /* CONFIG_MITIGATION_PAGE_TABLE_ISOLATION */ #endif /* __ASSEMBLY__ */ @@ -956,13 +999,13 @@ static inline int pte_same(pte_t a, pte_t b) return a.pte == b.pte; } -static inline pte_t pte_next_pfn(pte_t pte) +static inline pte_t pte_advance_pfn(pte_t pte, unsigned long nr) { if (__pte_needs_invert(pte_val(pte))) - return __pte(pte_val(pte) - (1UL << PFN_PTE_SHIFT)); - return __pte(pte_val(pte) + (1UL << PFN_PTE_SHIFT)); + return __pte(pte_val(pte) - (nr << PFN_PTE_SHIFT)); + return __pte(pte_val(pte) + (nr << PFN_PTE_SHIFT)); } -#define pte_next_pfn pte_next_pfn +#define pte_advance_pfn pte_advance_pfn static inline int pte_present(pte_t a) { @@ -1086,23 +1129,16 @@ static inline pmd_t *pud_pgtable(pud_t pud) */ #define pud_page(pud) pfn_to_page(pud_pfn(pud)) -#define pud_leaf pud_large -static inline int pud_large(pud_t pud) +#define pud_leaf pud_leaf +static inline bool pud_leaf(pud_t pud) { - return (pud_val(pud) & (_PAGE_PSE | _PAGE_PRESENT)) == - (_PAGE_PSE | _PAGE_PRESENT); + return pud_val(pud) & _PAGE_PSE; } static inline int pud_bad(pud_t pud) { return (pud_flags(pud) & ~(_KERNPG_TABLE | _PAGE_USER)) != 0; } -#else -#define pud_leaf pud_large -static inline int pud_large(pud_t pud) -{ - return 0; -} #endif /* CONFIG_PGTABLE_LEVELS > 2 */ #if CONFIG_PGTABLE_LEVELS > 3 @@ -1131,7 +1167,7 @@ static inline int p4d_bad(p4d_t p4d) { unsigned long ignore_flags = _KERNPG_TABLE | _PAGE_USER; - if (IS_ENABLED(CONFIG_PAGE_TABLE_ISOLATION)) + if (IS_ENABLED(CONFIG_MITIGATION_PAGE_TABLE_ISOLATION)) ignore_flags |= _PAGE_NX; return (p4d_flags(p4d) & ~ignore_flags) != 0; @@ -1177,7 +1213,7 @@ static inline int pgd_bad(pgd_t pgd) if (!pgtable_l5_enabled()) return 0; - if (IS_ENABLED(CONFIG_PAGE_TABLE_ISOLATION)) + if (IS_ENABLED(CONFIG_MITIGATION_PAGE_TABLE_ISOLATION)) ignore_flags |= _PAGE_NX; return (pgd_flags(pgd) & ~ignore_flags) != _KERNPG_TABLE; @@ -1207,7 +1243,6 @@ static inline int pgd_none(pgd_t pgd) extern int direct_gbpages; void init_mem_mapping(void); void early_alloc_pgt_buf(void); -extern void memblock_find_dma_reserve(void); void __init poking_init(void); unsigned long init_memory_mapping(unsigned long start, unsigned long end, pgprot_t prot); @@ -1401,10 +1436,28 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma, } #endif +#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD +static inline pud_t pudp_establish(struct vm_area_struct *vma, + unsigned long address, pud_t *pudp, pud_t pud) +{ + page_table_check_pud_set(vma->vm_mm, pudp, pud); + if (IS_ENABLED(CONFIG_SMP)) { + return xchg(pudp, pud); + } else { + pud_t old = *pudp; + WRITE_ONCE(*pudp, pud); + return old; + } +} +#endif + #define __HAVE_ARCH_PMDP_INVALIDATE_AD extern pmd_t pmdp_invalidate_ad(struct vm_area_struct *vma, unsigned long address, pmd_t *pmdp); +pud_t pudp_invalidate(struct vm_area_struct *vma, unsigned long address, + pud_t *pudp); + /* * Page table pages are page-aligned. The lower half of the top * level is used for userspace and the top half for the kernel. @@ -1419,12 +1472,12 @@ static inline bool pgdp_maps_userspace(void *__ptr) return (((ptr & ~PAGE_MASK) / sizeof(pgd_t)) < PGD_KERNEL_START); } -#define pgd_leaf pgd_large -static inline int pgd_large(pgd_t pgd) { return 0; } +#define pgd_leaf pgd_leaf +static inline bool pgd_leaf(pgd_t pgd) { return false; } -#ifdef CONFIG_PAGE_TABLE_ISOLATION +#ifdef CONFIG_MITIGATION_PAGE_TABLE_ISOLATION /* - * All top-level PAGE_TABLE_ISOLATION page tables are order-1 pages + * All top-level MITIGATION_PAGE_TABLE_ISOLATION page tables are order-1 pages * (8k-aligned and 8k in size). The kernel one is at the beginning 4k and * the user one is in the last 4k. To switch between them, you * just need to flip the 12th bit in their addresses. @@ -1469,7 +1522,7 @@ static inline p4d_t *user_to_kernel_p4dp(p4d_t *p4dp) { return ptr_clear_bit(p4dp, PTI_PGTABLE_SWITCH_BIT); } -#endif /* CONFIG_PAGE_TABLE_ISOLATION */ +#endif /* CONFIG_MITIGATION_PAGE_TABLE_ISOLATION */ /* * clone_pgd_range(pgd_t *dst, pgd_t *src, int count); @@ -1484,7 +1537,7 @@ static inline p4d_t *user_to_kernel_p4dp(p4d_t *p4dp) static inline void clone_pgd_range(pgd_t *dst, pgd_t *src, int count) { memcpy(dst, src, count * sizeof(pgd_t)); -#ifdef CONFIG_PAGE_TABLE_ISOLATION +#ifdef CONFIG_MITIGATION_PAGE_TABLE_ISOLATION if (!static_cpu_has(X86_FEATURE_PTI)) return; /* Clone the user space pgd as well */ @@ -1686,6 +1739,9 @@ void arch_check_zapped_pte(struct vm_area_struct *vma, pte_t pte); #define arch_check_zapped_pmd arch_check_zapped_pmd void arch_check_zapped_pmd(struct vm_area_struct *vma, pmd_t pmd); +#define arch_check_zapped_pud arch_check_zapped_pud +void arch_check_zapped_pud(struct vm_area_struct *vma, pud_t pud); + #ifdef CONFIG_XEN_PV #define arch_has_hw_nonleaf_pmd_young arch_has_hw_nonleaf_pmd_young static inline bool arch_has_hw_nonleaf_pmd_young(void) @@ -1719,6 +1775,43 @@ bool arch_is_platform_page(u64 paddr); #define arch_is_platform_page arch_is_platform_page #endif +/* + * Use set_p*_safe(), and elide TLB flushing, when confident that *no* + * TLB flush will be required as a result of the "set". For example, use + * in scenarios where it is known ahead of time that the routine is + * setting non-present entries, or re-setting an existing entry to the + * same value. Otherwise, use the typical "set" helpers and flush the + * TLB. + */ +#define set_pte_safe(ptep, pte) \ +({ \ + WARN_ON_ONCE(pte_present(*ptep) && !pte_same(*ptep, pte)); \ + set_pte(ptep, pte); \ +}) + +#define set_pmd_safe(pmdp, pmd) \ +({ \ + WARN_ON_ONCE(pmd_present(*pmdp) && !pmd_same(*pmdp, pmd)); \ + set_pmd(pmdp, pmd); \ +}) + +#define set_pud_safe(pudp, pud) \ +({ \ + WARN_ON_ONCE(pud_present(*pudp) && !pud_same(*pudp, pud)); \ + set_pud(pudp, pud); \ +}) + +#define set_p4d_safe(p4dp, p4d) \ +({ \ + WARN_ON_ONCE(p4d_present(*p4dp) && !p4d_same(*p4dp, p4d)); \ + set_p4d(p4dp, p4d); \ +}) + +#define set_pgd_safe(pgdp, pgd) \ +({ \ + WARN_ON_ONCE(pgd_present(*pgdp) && !pgd_same(*pgdp, pgd)); \ + set_pgd(pgdp, pgd); \ +}) #endif /* __ASSEMBLY__ */ #endif /* _ASM_X86_PGTABLE_H */ |