diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h index b78644962626..1201acf56a14 100644 --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -36,10 +36,12 @@ #define _PAGE_BIT_DEVMAP _PAGE_BIT_SOFTW4 #ifdef CONFIG_X86_64 -#define _PAGE_BIT_SAVED_DIRTY _PAGE_BIT_SOFTW5 /* Saved Dirty bit */ +#define _PAGE_BIT_SAVED_DIRTY _PAGE_BIT_SOFTW5 /* Saved Dirty bit (leaf) */ +#define _PAGE_BIT_NOPTISHADOW _PAGE_BIT_SOFTW5 /* No PTI shadow (root PGD) */ #else /* Shared with _PAGE_BIT_UFFD_WP which is not supported on 32 bit */ -#define _PAGE_BIT_SAVED_DIRTY _PAGE_BIT_SOFTW2 /* Saved Dirty bit */ +#define _PAGE_BIT_SAVED_DIRTY _PAGE_BIT_SOFTW2 /* Saved Dirty bit (leaf) */ +#define _PAGE_BIT_NOPTISHADOW _PAGE_BIT_SOFTW2 /* No PTI shadow (root PGD) */ #endif /* If _PAGE_BIT_PRESENT is clear, we use these: */ @@ -139,6 +141,8 @@ #define _PAGE_PROTNONE (_AT(pteval_t, 1) << _PAGE_BIT_PROTNONE) +#define _PAGE_NOPTISHADOW (_AT(pteval_t, 1) << _PAGE_BIT_NOPTISHADOW) + /* * Set of bits not changed in pte_modify. The pte's * protection key is treated like _PAGE_RW, for diff --git a/arch/x86/mm/ident_map.c b/arch/x86/mm/ident_map.c index a204a332c71f..fe0b2e66ded9 100644 --- a/arch/x86/mm/ident_map.c +++ b/arch/x86/mm/ident_map.c @@ -101,7 +101,7 @@ static int ident_p4d_init(struct x86_mapping_info *info, p4d_t *p4d_page, if (result) return result; - set_p4d(p4d, __p4d(__pa(pud) | info->kernpg_flag)); + set_p4d(p4d, __p4d(__pa(pud) | info->kernpg_flag | _PAGE_NOPTISHADOW)); } return 0; @@ -145,14 +145,14 @@ int kernel_ident_mapping_init(struct x86_mapping_info *info, pgd_t *pgd_page, if (result) return result; if (pgtable_l5_enabled()) { - set_pgd(pgd, __pgd(__pa(p4d) | info->kernpg_flag)); + set_pgd(pgd, __pgd(__pa(p4d) | info->kernpg_flag | _PAGE_NOPTISHADOW)); } else { /* * With p4d folded, pgd is equal to p4d. * The pgd entry has to point to the pud page table in this case. */ pud_t *pud = pud_offset(p4d, 0); - set_pgd(pgd, __pgd(__pa(pud) | info->kernpg_flag)); + set_pgd(pgd, __pgd(__pa(pud) | info->kernpg_flag | _PAGE_NOPTISHADOW)); } } diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c index d2032170167b..d4542651ed9e 100644 --- a/arch/x86/mm/pti.c +++ b/arch/x86/mm/pti.c @@ -132,7 +132,7 @@ pgd_t __pti_set_user_pgtbl(pgd_t *pgdp, pgd_t pgd) * Top-level entries added to init_mm's usermode pgd after boot * will not be automatically propagated to other mms. */ - if (!pgdp_maps_userspace(pgdp)) + if (!pgdp_maps_userspace(pgdp) || (pgd.pgd & _PAGE_NOPTISHADOW)) return pgd; /*