diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h index f560e6420267..212ce1b02e15 100644 --- a/arch/arm64/include/asm/pgtable-prot.h +++ b/arch/arm64/include/asm/pgtable-prot.h @@ -25,6 +25,8 @@ */ #define PTE_PRESENT_INVALID (PTE_NG) /* only when !PTE_VALID */ +#define PTE_PRESENT_VALID_KERNEL (PTE_VALID | PTE_MAYBE_NG) + #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP #define PTE_UFFD_WP (_AT(pteval_t, 1) << 58) /* uffd-wp tracking */ #define PTE_SWP_UFFD_WP (_AT(pteval_t, 1) << 3) /* only for swp ptes */ diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index b3e58735c49b..dd062179b9b6 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -322,9 +322,11 @@ static inline pte_t pte_mknoncont(pte_t pte) return clear_pte_bit(pte, __pgprot(PTE_CONT)); } -static inline pte_t pte_mkvalid(pte_t pte) +static inline pte_t pte_mkvalid_k(pte_t pte) { - return set_pte_bit(pte, __pgprot(PTE_VALID)); + pte = clear_pte_bit(pte, __pgprot(PTE_PRESENT_INVALID)); + pte = set_pte_bit(pte, __pgprot(PTE_PRESENT_VALID_KERNEL)); + return pte; } static inline pte_t pte_mkinvalid(pte_t pte) @@ -594,6 +596,7 @@ static inline int pmd_protnone(pmd_t pmd) #define pmd_mkclean(pmd) pte_pmd(pte_mkclean(pmd_pte(pmd))) #define pmd_mkdirty(pmd) pte_pmd(pte_mkdirty(pmd_pte(pmd))) #define pmd_mkyoung(pmd) pte_pmd(pte_mkyoung(pmd_pte(pmd))) +#define pmd_mkvalid_k(pmd) pte_pmd(pte_mkvalid_k(pmd_pte(pmd))) #define pmd_mkinvalid(pmd) pte_pmd(pte_mkinvalid(pmd_pte(pmd))) #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP #define pmd_uffd_wp(pmd) pte_uffd_wp(pmd_pte(pmd)) @@ -635,6 +638,8 @@ static inline pmd_t pmd_mkspecial(pmd_t pmd) #define pud_young(pud) pte_young(pud_pte(pud)) #define pud_mkyoung(pud) pte_pud(pte_mkyoung(pud_pte(pud))) +#define pud_mkwrite_novma(pud) pte_pud(pte_mkwrite_novma(pud_pte(pud))) +#define pud_mkvalid_k(pud) pte_pud(pte_mkvalid_k(pud_pte(pud))) #define pud_write(pud) pte_write(pud_pte(pud)) static inline pud_t pud_mkhuge(pud_t pud) diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 223947487a22..1575680675d8 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -602,6 +602,8 @@ static int split_pmd(pmd_t *pmdp, pmd_t pmd, gfp_t gfp, bool to_cont) tableprot |= PMD_TABLE_PXN; prot = __pgprot((pgprot_val(prot) & ~PTE_TYPE_MASK) | PTE_TYPE_PAGE); + if (!pmd_valid(pmd)) + prot = pte_pgprot(pte_mkinvalid(pfn_pte(0, prot))); prot = __pgprot(pgprot_val(prot) & ~PTE_CONT); if (to_cont) prot = __pgprot(pgprot_val(prot) | PTE_CONT); @@ -647,6 +649,8 @@ static int split_pud(pud_t *pudp, pud_t pud, gfp_t gfp, bool to_cont) tableprot |= PUD_TABLE_PXN; prot = __pgprot((pgprot_val(prot) & ~PMD_TYPE_MASK) | PMD_TYPE_SECT); + if (!pud_valid(pud)) + prot = pmd_pgprot(pmd_mkinvalid(pfn_pmd(0, prot))); prot = __pgprot(pgprot_val(prot) & ~PTE_CONT); if (to_cont) prot = __pgprot(pgprot_val(prot) | PTE_CONT); diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c index 358d1dc9a576..ce035e1b4eaf 100644 --- a/arch/arm64/mm/pageattr.c +++ b/arch/arm64/mm/pageattr.c @@ -25,6 +25,11 @@ static ptdesc_t set_pageattr_masks(ptdesc_t val, struct mm_walk *walk) { struct page_change_data *masks = walk->private; + /* + * Some users clear and set bits which alias each other (e.g. PTE_NG and + * PTE_PRESENT_INVALID). It is therefore important that we always clear + * first then set. + */ val &= ~(pgprot_val(masks->clear_mask)); val |= (pgprot_val(masks->set_mask)); @@ -36,7 +41,7 @@ static int pageattr_pud_entry(pud_t *pud, unsigned long addr, { pud_t val = pudp_get(pud); - if (pud_sect(val)) { + if (pud_leaf(val)) { if (WARN_ON_ONCE((next - addr) != PUD_SIZE)) return -EINVAL; val = __pud(set_pageattr_masks(pud_val(val), walk)); @@ -52,7 +57,7 @@ static int pageattr_pmd_entry(pmd_t *pmd, unsigned long addr, { pmd_t val = pmdp_get(pmd); - if (pmd_sect(val)) { + if (pmd_leaf(val)) { if (WARN_ON_ONCE((next - addr) != PMD_SIZE)) return -EINVAL; val = __pmd(set_pageattr_masks(pmd_val(val), walk)); @@ -132,11 +137,12 @@ static int __change_memory_common(unsigned long start, unsigned long size, ret = update_range_prot(start, size, set_mask, clear_mask); /* - * If the memory is being made valid without changing any other bits - * then a TLBI isn't required as a non-valid entry cannot be cached in - * the TLB. + * If the memory is being switched from present-invalid to valid without + * changing any other bits then a TLBI isn't required as a non-valid + * entry cannot be cached in the TLB. */ - if (pgprot_val(set_mask) != PTE_VALID || pgprot_val(clear_mask)) + if (pgprot_val(set_mask) != PTE_PRESENT_VALID_KERNEL || + pgprot_val(clear_mask) != PTE_PRESENT_INVALID) flush_tlb_kernel_range(start, start + size); return ret; } @@ -237,18 +243,18 @@ int set_memory_valid(unsigned long addr, int numpages, int enable) { if (enable) return __change_memory_common(addr, PAGE_SIZE * numpages, - __pgprot(PTE_VALID), - __pgprot(0)); + __pgprot(PTE_PRESENT_VALID_KERNEL), + __pgprot(PTE_PRESENT_INVALID)); else return __change_memory_common(addr, PAGE_SIZE * numpages, - __pgprot(0), - __pgprot(PTE_VALID)); + __pgprot(PTE_PRESENT_INVALID), + __pgprot(PTE_PRESENT_VALID_KERNEL)); } int set_direct_map_invalid_noflush(struct page *page) { - pgprot_t clear_mask = __pgprot(PTE_VALID); - pgprot_t set_mask = __pgprot(0); + pgprot_t clear_mask = __pgprot(PTE_PRESENT_VALID_KERNEL); + pgprot_t set_mask = __pgprot(PTE_PRESENT_INVALID); if (!can_set_direct_map()) return 0; @@ -259,8 +265,8 @@ int set_direct_map_invalid_noflush(struct page *page) int set_direct_map_default_noflush(struct page *page) { - pgprot_t set_mask = __pgprot(PTE_VALID | PTE_WRITE); - pgprot_t clear_mask = __pgprot(PTE_RDONLY); + pgprot_t set_mask = __pgprot(PTE_PRESENT_VALID_KERNEL | PTE_WRITE); + pgprot_t clear_mask = __pgprot(PTE_PRESENT_INVALID | PTE_RDONLY); if (!can_set_direct_map()) return 0; @@ -296,8 +302,8 @@ static int __set_memory_enc_dec(unsigned long addr, * entries or Synchronous External Aborts caused by RIPAS_EMPTY */ ret = __change_memory_common(addr, PAGE_SIZE * numpages, - __pgprot(set_prot), - __pgprot(clear_prot | PTE_VALID)); + __pgprot(set_prot | PTE_PRESENT_INVALID), + __pgprot(clear_prot | PTE_PRESENT_VALID_KERNEL)); if (ret) return ret; @@ -311,8 +317,8 @@ static int __set_memory_enc_dec(unsigned long addr, return ret; return __change_memory_common(addr, PAGE_SIZE * numpages, - __pgprot(PTE_VALID), - __pgprot(0)); + __pgprot(PTE_PRESENT_VALID_KERNEL), + __pgprot(PTE_PRESENT_INVALID)); } static int realm_set_memory_encrypted(unsigned long addr, int numpages) @@ -404,15 +410,15 @@ bool kernel_page_present(struct page *page) pud = READ_ONCE(*pudp); if (pud_none(pud)) return false; - if (pud_sect(pud)) - return true; + if (pud_leaf(pud)) + return pud_valid(pud); pmdp = pmd_offset(pudp, addr); pmd = READ_ONCE(*pmdp); if (pmd_none(pmd)) return false; - if (pmd_sect(pmd)) - return true; + if (pmd_leaf(pmd)) + return pmd_valid(pmd); ptep = pte_offset_kernel(pmdp, addr); return pte_valid(__ptep_get(ptep)); diff --git a/arch/arm64/mm/trans_pgd.c b/arch/arm64/mm/trans_pgd.c index 18543b603c77..cca9706a875c 100644 --- a/arch/arm64/mm/trans_pgd.c +++ b/arch/arm64/mm/trans_pgd.c @@ -31,36 +31,6 @@ static void *trans_alloc(struct trans_pgd_info *info) return info->trans_alloc_page(info->trans_alloc_arg); } -static void _copy_pte(pte_t *dst_ptep, pte_t *src_ptep, unsigned long addr) -{ - pte_t pte = __ptep_get(src_ptep); - - if (pte_valid(pte)) { - /* - * Resume will overwrite areas that may be marked - * read only (code, rodata). Clear the RDONLY bit from - * the temporary mappings we use during restore. - */ - __set_pte(dst_ptep, pte_mkwrite_novma(pte)); - } else if (!pte_none(pte)) { - /* - * debug_pagealloc will removed the PTE_VALID bit if - * the page isn't in use by the resume kernel. It may have - * been in use by the original kernel, in which case we need - * to put it back in our copy to do the restore. - * - * Other cases include kfence / vmalloc / memfd_secret which - * may call `set_direct_map_invalid_noflush()`. - * - * Before marking this entry valid, check the pfn should - * be mapped. - */ - BUG_ON(!pfn_valid(pte_pfn(pte))); - - __set_pte(dst_ptep, pte_mkvalid(pte_mkwrite_novma(pte))); - } -} - static int copy_pte(struct trans_pgd_info *info, pmd_t *dst_pmdp, pmd_t *src_pmdp, unsigned long start, unsigned long end) { @@ -76,7 +46,11 @@ static int copy_pte(struct trans_pgd_info *info, pmd_t *dst_pmdp, src_ptep = pte_offset_kernel(src_pmdp, start); do { - _copy_pte(dst_ptep, src_ptep, addr); + pte_t pte = __ptep_get(src_ptep); + + if (pte_none(pte)) + continue; + __set_pte(dst_ptep, pte_mkvalid_k(pte_mkwrite_novma(pte))); } while (dst_ptep++, src_ptep++, addr += PAGE_SIZE, addr != end); return 0; @@ -109,8 +83,7 @@ static int copy_pmd(struct trans_pgd_info *info, pud_t *dst_pudp, if (copy_pte(info, dst_pmdp, src_pmdp, addr, next)) return -ENOMEM; } else { - set_pmd(dst_pmdp, - __pmd(pmd_val(pmd) & ~PMD_SECT_RDONLY)); + set_pmd(dst_pmdp, pmd_mkvalid_k(pmd_mkwrite_novma(pmd))); } } while (dst_pmdp++, src_pmdp++, addr = next, addr != end); @@ -145,8 +118,7 @@ static int copy_pud(struct trans_pgd_info *info, p4d_t *dst_p4dp, if (copy_pmd(info, dst_pudp, src_pudp, addr, next)) return -ENOMEM; } else { - set_pud(dst_pudp, - __pud(pud_val(pud) & ~PUD_SECT_RDONLY)); + set_pud(dst_pudp, pud_mkvalid_k(pud_mkwrite_novma(pud))); } } while (dst_pudp++, src_pudp++, addr = next, addr != end);