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pgtable.h
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pgtable.h
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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_PGTABLE_H
#define _ASM_X86_PGTABLE_H
#include <linux/mem_encrypt.h>
#include <asm/page.h>
#include <asm/pgtable_types.h>
/*
* Macro to mark a page protection value as UC-
*/
#define pgprot_noncached(prot) \
((boot_cpu_data.x86 > 3) \
? (__pgprot(pgprot_val(prot) | \
cachemode2protval(_PAGE_CACHE_MODE_UC_MINUS))) \
: (prot))
#ifndef __ASSEMBLY__
#include <linux/spinlock.h>
#include <asm/x86_init.h>
#include <asm/pkru.h>
#include <asm/fpu/api.h>
#include <asm/coco.h>
#include <asm-generic/pgtable_uffd.h>
#include <linux/page_table_check.h>
extern pgd_t early_top_pgt[PTRS_PER_PGD];
bool __init __early_make_pgtable(unsigned long address, pmdval_t pmd);
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);
bool ptdump_walk_pgd_level_checkwx(void);
#define ptdump_check_wx ptdump_walk_pgd_level_checkwx
void ptdump_walk_user_pgd_level_checkwx(void);
/*
* Macros to add or remove encryption attribute
*/
#define pgprot_encrypted(prot) __pgprot(cc_mkenc(pgprot_val(prot)))
#define pgprot_decrypted(prot) __pgprot(cc_mkdec(pgprot_val(prot)))
#ifdef CONFIG_DEBUG_WX
#define debug_checkwx_user() ptdump_walk_user_pgd_level_checkwx()
#else
#define debug_checkwx_user() do { } while (0)
#endif
/*
* ZERO_PAGE is a global shared page that is always zero: used
* for zero-mapped memory areas etc..
*/
extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
__visible;
#define ZERO_PAGE(vaddr) ((void)(vaddr),virt_to_page(empty_zero_page))
extern spinlock_t pgd_lock;
extern struct list_head pgd_list;
extern struct mm_struct *pgd_page_get_mm(struct page *page);
extern pmdval_t early_pmd_flags;
#ifdef CONFIG_PARAVIRT_XXL
#include <asm/paravirt.h>
#else /* !CONFIG_PARAVIRT_XXL */
#define set_pte(ptep, pte) native_set_pte(ptep, pte)
#define set_pte_atomic(ptep, pte) \
native_set_pte_atomic(ptep, pte)
#define set_pmd(pmdp, pmd) native_set_pmd(pmdp, pmd)
#ifndef __PAGETABLE_P4D_FOLDED
#define set_pgd(pgdp, pgd) native_set_pgd(pgdp, pgd)
#define pgd_clear(pgd) (pgtable_l5_enabled() ? native_pgd_clear(pgd) : 0)
#endif
#ifndef set_p4d
# define set_p4d(p4dp, p4d) native_set_p4d(p4dp, p4d)
#endif
#ifndef __PAGETABLE_PUD_FOLDED
#define p4d_clear(p4d) native_p4d_clear(p4d)
#endif
#ifndef set_pud
# define set_pud(pudp, pud) native_set_pud(pudp, pud)
#endif
#ifndef __PAGETABLE_PUD_FOLDED
#define pud_clear(pud) native_pud_clear(pud)
#endif
#define pte_clear(mm, addr, ptep) native_pte_clear(mm, addr, ptep)
#define pmd_clear(pmd) native_pmd_clear(pmd)
#define pgd_val(x) native_pgd_val(x)
#define __pgd(x) native_make_pgd(x)
#ifndef __PAGETABLE_P4D_FOLDED
#define p4d_val(x) native_p4d_val(x)
#define __p4d(x) native_make_p4d(x)
#endif
#ifndef __PAGETABLE_PUD_FOLDED
#define pud_val(x) native_pud_val(x)
#define __pud(x) native_make_pud(x)
#endif
#ifndef __PAGETABLE_PMD_FOLDED
#define pmd_val(x) native_pmd_val(x)
#define __pmd(x) native_make_pmd(x)
#endif
#define pte_val(x) native_pte_val(x)
#define __pte(x) native_make_pte(x)
#define arch_end_context_switch(prev) do {} while(0)
#endif /* CONFIG_PARAVIRT_XXL */
/*
* The following only work if pte_present() is true.
* Undefined behaviour if not..
*/
static inline bool pte_dirty(pte_t pte)
{
return pte_flags(pte) & _PAGE_DIRTY_BITS;
}
static inline bool pte_shstk(pte_t pte)
{
return cpu_feature_enabled(X86_FEATURE_SHSTK) &&
(pte_flags(pte) & (_PAGE_RW | _PAGE_DIRTY)) == _PAGE_DIRTY;
}
static inline int pte_young(pte_t pte)
{
return pte_flags(pte) & _PAGE_ACCESSED;
}
#define pmd_dirty pmd_dirty
static inline bool pmd_dirty(pmd_t pmd)
{
return pmd_flags(pmd) & _PAGE_DIRTY_BITS;
}
static inline bool pmd_shstk(pmd_t pmd)
{
return cpu_feature_enabled(X86_FEATURE_SHSTK) &&
(pmd_flags(pmd) & (_PAGE_RW | _PAGE_DIRTY | _PAGE_PSE)) ==
(_PAGE_DIRTY | _PAGE_PSE);
}
#define pmd_young pmd_young
static inline int pmd_young(pmd_t pmd)
{
return pmd_flags(pmd) & _PAGE_ACCESSED;
}
static inline bool pud_dirty(pud_t pud)
{
return pud_flags(pud) & _PAGE_DIRTY_BITS;
}
static inline int pud_young(pud_t pud)
{
return pud_flags(pud) & _PAGE_ACCESSED;
}
static inline int pte_write(pte_t pte)
{
/*
* Shadow stack pages are logically writable, but do not have
* _PAGE_RW. Check for them separately from _PAGE_RW itself.
*/
return (pte_flags(pte) & _PAGE_RW) || pte_shstk(pte);
}
#define pmd_write pmd_write
static inline int pmd_write(pmd_t pmd)
{
/*
* Shadow stack pages are logically writable, but do not have
* _PAGE_RW. Check for them separately from _PAGE_RW itself.
*/
return (pmd_flags(pmd) & _PAGE_RW) || pmd_shstk(pmd);
}
#define pud_write pud_write
static inline int pud_write(pud_t pud)
{
return pud_flags(pud) & _PAGE_RW;
}
static inline int pte_huge(pte_t pte)
{
return pte_flags(pte) & _PAGE_PSE;
}
static inline int pte_global(pte_t pte)
{
return pte_flags(pte) & _PAGE_GLOBAL;
}
static inline int pte_exec(pte_t pte)
{
return !(pte_flags(pte) & _PAGE_NX);
}
static inline int pte_special(pte_t pte)
{
return pte_flags(pte) & _PAGE_SPECIAL;
}
/* Entries that were set to PROT_NONE are inverted */
static inline u64 protnone_mask(u64 val);
#define PFN_PTE_SHIFT PAGE_SHIFT
static inline unsigned long pte_pfn(pte_t pte)
{
phys_addr_t pfn = pte_val(pte);
pfn ^= protnone_mask(pfn);
return (pfn & PTE_PFN_MASK) >> PAGE_SHIFT;
}
static inline unsigned long pmd_pfn(pmd_t pmd)
{
phys_addr_t pfn = pmd_val(pmd);
pfn ^= protnone_mask(pfn);
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);
pfn ^= protnone_mask(pfn);
return (pfn & pud_pfn_mask(pud)) >> PAGE_SHIFT;
}
static inline unsigned long p4d_pfn(p4d_t p4d)
{
return (p4d_val(p4d) & p4d_pfn_mask(p4d)) >> PAGE_SHIFT;
}
static inline unsigned long pgd_pfn(pgd_t pgd)
{
return (pgd_val(pgd) & PTE_PFN_MASK) >> PAGE_SHIFT;
}
#define p4d_leaf p4d_leaf
static inline bool p4d_leaf(p4d_t p4d)
{
/* No 512 GiB pages yet */
return 0;
}
#define pte_page(pte) pfn_to_page(pte_pfn(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_leaf */
static inline int pmd_trans_huge(pmd_t pmd)
{
return (pmd_val(pmd) & (_PAGE_PSE|_PAGE_DEVMAP)) == _PAGE_PSE;
}
#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
static inline int pud_trans_huge(pud_t pud)
{
return (pud_val(pud) & (_PAGE_PSE|_PAGE_DEVMAP)) == _PAGE_PSE;
}
#endif
#define has_transparent_hugepage has_transparent_hugepage
static inline int has_transparent_hugepage(void)
{
return boot_cpu_has(X86_FEATURE_PSE);
}
#ifdef CONFIG_ARCH_HAS_PTE_DEVMAP
static inline int pmd_devmap(pmd_t pmd)
{
return !!(pmd_val(pmd) & _PAGE_DEVMAP);
}
#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
static inline int pud_devmap(pud_t pud)
{
return !!(pud_val(pud) & _PAGE_DEVMAP);
}
#else
static inline int pud_devmap(pud_t pud)
{
return 0;
}
#endif
static inline int pgd_devmap(pgd_t pgd)
{
return 0;
}
#endif
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
static inline pte_t pte_set_flags(pte_t pte, pteval_t set)
{
pteval_t v = native_pte_val(pte);
return native_make_pte(v | set);
}
static inline pte_t pte_clear_flags(pte_t pte, pteval_t clear)
{
pteval_t v = native_pte_val(pte);
return native_make_pte(v & ~clear);
}
/*
* Write protection operations can result in Dirty=1,Write=0 PTEs. But in the
* case of X86_FEATURE_USER_SHSTK, these PTEs denote shadow stack memory. So
* when creating dirty, write-protected memory, a software bit is used:
* _PAGE_BIT_SAVED_DIRTY. The following functions take a PTE and transition the
* Dirty bit to SavedDirty, and vice-vesra.
*
* This shifting is only done if needed. In the case of shifting
* Dirty->SavedDirty, the condition is if the PTE is Write=0. In the case of
* shifting SavedDirty->Dirty, the condition is Write=1.
*/
static inline pgprotval_t mksaveddirty_shift(pgprotval_t v)
{
pgprotval_t cond = (~v >> _PAGE_BIT_RW) & 1;
v |= ((v >> _PAGE_BIT_DIRTY) & cond) << _PAGE_BIT_SAVED_DIRTY;
v &= ~(cond << _PAGE_BIT_DIRTY);
return v;
}
static inline pgprotval_t clear_saveddirty_shift(pgprotval_t v)
{
pgprotval_t cond = (v >> _PAGE_BIT_RW) & 1;
v |= ((v >> _PAGE_BIT_SAVED_DIRTY) & cond) << _PAGE_BIT_DIRTY;
v &= ~(cond << _PAGE_BIT_SAVED_DIRTY);
return v;
}
static inline pte_t pte_mksaveddirty(pte_t pte)
{
pteval_t v = native_pte_val(pte);
v = mksaveddirty_shift(v);
return native_make_pte(v);
}
static inline pte_t pte_clear_saveddirty(pte_t pte)
{
pteval_t v = native_pte_val(pte);
v = clear_saveddirty_shift(v);
return native_make_pte(v);
}
static inline pte_t pte_wrprotect(pte_t pte)
{
pte = pte_clear_flags(pte, _PAGE_RW);
/*
* Blindly clearing _PAGE_RW might accidentally create
* a shadow stack PTE (Write=0,Dirty=1). Move the hardware
* dirty value to the software bit, if present.
*/
return pte_mksaveddirty(pte);
}
#ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP
static inline int pte_uffd_wp(pte_t pte)
{
return pte_flags(pte) & _PAGE_UFFD_WP;
}
static inline pte_t pte_mkuffd_wp(pte_t pte)
{
return pte_wrprotect(pte_set_flags(pte, _PAGE_UFFD_WP));
}
static inline pte_t pte_clear_uffd_wp(pte_t pte)
{
return pte_clear_flags(pte, _PAGE_UFFD_WP);
}
#endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */
static inline pte_t pte_mkclean(pte_t pte)
{
return pte_clear_flags(pte, _PAGE_DIRTY_BITS);
}
static inline pte_t pte_mkold(pte_t pte)
{
return pte_clear_flags(pte, _PAGE_ACCESSED);
}
static inline pte_t pte_mkexec(pte_t pte)
{
return pte_clear_flags(pte, _PAGE_NX);
}
static inline pte_t pte_mkdirty(pte_t pte)
{
pte = pte_set_flags(pte, _PAGE_DIRTY | _PAGE_SOFT_DIRTY);
return pte_mksaveddirty(pte);
}
static inline pte_t pte_mkwrite_shstk(pte_t pte)
{
pte = pte_clear_flags(pte, _PAGE_RW);
return pte_set_flags(pte, _PAGE_DIRTY);
}
static inline pte_t pte_mkyoung(pte_t pte)
{
return pte_set_flags(pte, _PAGE_ACCESSED);
}
static inline pte_t pte_mkwrite_novma(pte_t pte)
{
return pte_set_flags(pte, _PAGE_RW);
}
struct vm_area_struct;
pte_t pte_mkwrite(pte_t pte, struct vm_area_struct *vma);
#define pte_mkwrite pte_mkwrite
static inline pte_t pte_mkhuge(pte_t pte)
{
return pte_set_flags(pte, _PAGE_PSE);
}
static inline pte_t pte_clrhuge(pte_t pte)
{
return pte_clear_flags(pte, _PAGE_PSE);
}
static inline pte_t pte_mkglobal(pte_t pte)
{
return pte_set_flags(pte, _PAGE_GLOBAL);
}
static inline pte_t pte_clrglobal(pte_t pte)
{
return pte_clear_flags(pte, _PAGE_GLOBAL);
}
static inline pte_t pte_mkspecial(pte_t pte)
{
return pte_set_flags(pte, _PAGE_SPECIAL);
}
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)
{
pmdval_t v = native_pmd_val(pmd);
v = mksaveddirty_shift(v);
return native_make_pmd(v);
}
/* See comments above mksaveddirty_shift() */
static inline pmd_t pmd_clear_saveddirty(pmd_t pmd)
{
pmdval_t v = native_pmd_val(pmd);
v = clear_saveddirty_shift(v);
return native_make_pmd(v);
}
static inline pmd_t pmd_wrprotect(pmd_t pmd)
{
pmd = pmd_clear_flags(pmd, _PAGE_RW);
/*
* Blindly clearing _PAGE_RW might accidentally create
* a shadow stack PMD (RW=0, Dirty=1). Move the hardware
* dirty value to the software bit.
*/
return pmd_mksaveddirty(pmd);
}
#ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP
static inline int pmd_uffd_wp(pmd_t pmd)
{
return pmd_flags(pmd) & _PAGE_UFFD_WP;
}
static inline pmd_t pmd_mkuffd_wp(pmd_t pmd)
{
return pmd_wrprotect(pmd_set_flags(pmd, _PAGE_UFFD_WP));
}
static inline pmd_t pmd_clear_uffd_wp(pmd_t pmd)
{
return pmd_clear_flags(pmd, _PAGE_UFFD_WP);
}
#endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */
static inline pmd_t pmd_mkold(pmd_t pmd)
{
return pmd_clear_flags(pmd, _PAGE_ACCESSED);
}
static inline pmd_t pmd_mkclean(pmd_t pmd)
{
return pmd_clear_flags(pmd, _PAGE_DIRTY_BITS);
}
static inline pmd_t pmd_mkdirty(pmd_t pmd)
{
pmd = pmd_set_flags(pmd, _PAGE_DIRTY | _PAGE_SOFT_DIRTY);
return pmd_mksaveddirty(pmd);
}
static inline pmd_t pmd_mkwrite_shstk(pmd_t pmd)
{
pmd = pmd_clear_flags(pmd, _PAGE_RW);
return pmd_set_flags(pmd, _PAGE_DIRTY);
}
static inline pmd_t pmd_mkdevmap(pmd_t pmd)
{
return pmd_set_flags(pmd, _PAGE_DEVMAP);
}
static inline pmd_t pmd_mkhuge(pmd_t pmd)
{
return pmd_set_flags(pmd, _PAGE_PSE);
}
static inline pmd_t pmd_mkyoung(pmd_t pmd)
{
return pmd_set_flags(pmd, _PAGE_ACCESSED);
}
static inline pmd_t pmd_mkwrite_novma(pmd_t pmd)
{
return pmd_set_flags(pmd, _PAGE_RW);
}
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)
{
pudval_t v = native_pud_val(pud);
v = mksaveddirty_shift(v);
return native_make_pud(v);
}
/* See comments above mksaveddirty_shift() */
static inline pud_t pud_clear_saveddirty(pud_t pud)
{
pudval_t v = native_pud_val(pud);
v = clear_saveddirty_shift(v);
return native_make_pud(v);
}
static inline pud_t pud_mkold(pud_t pud)
{
return pud_clear_flags(pud, _PAGE_ACCESSED);
}
static inline pud_t pud_mkclean(pud_t pud)
{
return pud_clear_flags(pud, _PAGE_DIRTY_BITS);
}
static inline pud_t pud_wrprotect(pud_t pud)
{
pud = pud_clear_flags(pud, _PAGE_RW);
/*
* Blindly clearing _PAGE_RW might accidentally create
* a shadow stack PUD (RW=0, Dirty=1). Move the hardware
* dirty value to the software bit.
*/
return pud_mksaveddirty(pud);
}
static inline pud_t pud_mkdirty(pud_t pud)
{
pud = pud_set_flags(pud, _PAGE_DIRTY | _PAGE_SOFT_DIRTY);
return pud_mksaveddirty(pud);
}
static inline pud_t pud_mkdevmap(pud_t pud)
{
return pud_set_flags(pud, _PAGE_DEVMAP);
}
static inline pud_t pud_mkhuge(pud_t pud)
{
return pud_set_flags(pud, _PAGE_PSE);
}
static inline pud_t pud_mkyoung(pud_t pud)
{
return pud_set_flags(pud, _PAGE_ACCESSED);
}
static inline pud_t pud_mkwrite(pud_t pud)
{
pud = pud_set_flags(pud, _PAGE_RW);
return pud_clear_saveddirty(pud);
}
#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY
static inline int pte_soft_dirty(pte_t pte)
{
return pte_flags(pte) & _PAGE_SOFT_DIRTY;
}
static inline int pmd_soft_dirty(pmd_t pmd)
{
return pmd_flags(pmd) & _PAGE_SOFT_DIRTY;
}
static inline int pud_soft_dirty(pud_t pud)
{
return pud_flags(pud) & _PAGE_SOFT_DIRTY;
}
static inline pte_t pte_mksoft_dirty(pte_t pte)
{
return pte_set_flags(pte, _PAGE_SOFT_DIRTY);
}
static inline pmd_t pmd_mksoft_dirty(pmd_t pmd)
{
return pmd_set_flags(pmd, _PAGE_SOFT_DIRTY);
}
static inline pud_t pud_mksoft_dirty(pud_t pud)
{
return pud_set_flags(pud, _PAGE_SOFT_DIRTY);
}
static inline pte_t pte_clear_soft_dirty(pte_t pte)
{
return pte_clear_flags(pte, _PAGE_SOFT_DIRTY);
}
static inline pmd_t pmd_clear_soft_dirty(pmd_t pmd)
{
return pmd_clear_flags(pmd, _PAGE_SOFT_DIRTY);
}
static inline pud_t pud_clear_soft_dirty(pud_t pud)
{
return pud_clear_flags(pud, _PAGE_SOFT_DIRTY);
}
#endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */
/*
* Mask out unsupported bits in a present pgprot. Non-present pgprots
* can use those bits for other purposes, so leave them be.
*/
static inline pgprotval_t massage_pgprot(pgprot_t pgprot)
{
pgprotval_t protval = pgprot_val(pgprot);
if (protval & _PAGE_PRESENT)
protval &= __supported_pte_mask;
return protval;
}
static inline pgprotval_t check_pgprot(pgprot_t pgprot)
{
pgprotval_t massaged_val = massage_pgprot(pgprot);
/* mmdebug.h can not be included here because of dependencies */
#ifdef CONFIG_DEBUG_VM
WARN_ONCE(pgprot_val(pgprot) != massaged_val,
"attempted to set unsupported pgprot: %016llx "
"bits: %016llx supported: %016llx\n",
(u64)pgprot_val(pgprot),
(u64)pgprot_val(pgprot) ^ massaged_val,
(u64)__supported_pte_mask);
#endif
return massaged_val;
}
static inline pte_t pfn_pte(unsigned long page_nr, pgprot_t pgprot)
{
phys_addr_t pfn = (phys_addr_t)page_nr << PAGE_SHIFT;
pfn ^= protnone_mask(pgprot_val(pgprot));
pfn &= PTE_PFN_MASK;
return __pte(pfn | check_pgprot(pgprot));
}
static inline pmd_t pfn_pmd(unsigned long page_nr, pgprot_t pgprot)
{
phys_addr_t pfn = (phys_addr_t)page_nr << PAGE_SHIFT;
pfn ^= protnone_mask(pgprot_val(pgprot));
pfn &= PHYSICAL_PMD_PAGE_MASK;
return __pmd(pfn | check_pgprot(pgprot));
}
static inline pud_t pfn_pud(unsigned long page_nr, pgprot_t pgprot)
{
phys_addr_t pfn = (phys_addr_t)page_nr << PAGE_SHIFT;
pfn ^= protnone_mask(pgprot_val(pgprot));
pfn &= PHYSICAL_PUD_PAGE_MASK;
return __pud(pfn | check_pgprot(pgprot));
}
static inline pmd_t pmd_mkinvalid(pmd_t pmd)
{
return pfn_pmd(pmd_pfn(pmd),
__pgprot(pmd_flags(pmd) & ~(_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)
{
pteval_t val = pte_val(pte), oldval = val;
pte_t pte_result;
/*
* Chop off the NX bit (if present), and add the NX portion of
* the newprot (if present):
*/
val &= _PAGE_CHG_MASK;
val |= check_pgprot(newprot) & ~_PAGE_CHG_MASK;
val = flip_protnone_guard(oldval, val, PTE_PFN_MASK);
pte_result = __pte(val);
/*
* To avoid creating Write=0,Dirty=1 PTEs, pte_modify() needs to avoid:
* 1. Marking Write=0 PTEs Dirty=1
* 2. Marking Dirty=1 PTEs 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.
*/
if (oldval & _PAGE_RW)
pte_result = pte_mksaveddirty(pte_result);
else
pte_result = pte_clear_saveddirty(pte_result);
return pte_result;
}
static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
{
pmdval_t val = pmd_val(pmd), oldval = val;
pmd_t pmd_result;
val &= (_HPAGE_CHG_MASK & ~_PAGE_DIRTY);
val |= check_pgprot(newprot) & ~_HPAGE_CHG_MASK;
val = flip_protnone_guard(oldval, val, PHYSICAL_PMD_PAGE_MASK);
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.
*/
if (oldval & _PAGE_RW)
pmd_result = pmd_mksaveddirty(pmd_result);
else
pmd_result = pmd_clear_saveddirty(pmd_result);
return pmd_result;
}
/*
* mprotect needs to preserve PAT and encryption bits when updating
* vm_page_prot
*/
#define pgprot_modify pgprot_modify
static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
{
pgprotval_t preservebits = pgprot_val(oldprot) & _PAGE_CHG_MASK;
pgprotval_t addbits = pgprot_val(newprot) & ~_PAGE_CHG_MASK;
return __pgprot(preservebits | addbits);
}
#define pte_pgprot(x) __pgprot(pte_flags(x))
#define pmd_pgprot(x) __pgprot(pmd_flags(x))
#define pud_pgprot(x) __pgprot(pud_flags(x))
#define p4d_pgprot(x) __pgprot(p4d_flags(x))
#define canon_pgprot(p) __pgprot(massage_pgprot(p))
static inline int is_new_memtype_allowed(u64 paddr, unsigned long size,
enum page_cache_mode pcm,
enum page_cache_mode new_pcm)
{
/*
* PAT type is always WB for untracked ranges, so no need to check.
*/
if (x86_platform.is_untracked_pat_range(paddr, paddr + size))
return 1;
/*
* Certain new memtypes are not allowed with certain
* requested memtype:
* - request is uncached, return cannot be write-back
* - request is write-combine, return cannot be write-back
* - request is write-through, return cannot be write-back
* - request is write-through, return cannot be write-combine
*/
if ((pcm == _PAGE_CACHE_MODE_UC_MINUS &&
new_pcm == _PAGE_CACHE_MODE_WB) ||
(pcm == _PAGE_CACHE_MODE_WC &&
new_pcm == _PAGE_CACHE_MODE_WB) ||
(pcm == _PAGE_CACHE_MODE_WT &&
new_pcm == _PAGE_CACHE_MODE_WB) ||
(pcm == _PAGE_CACHE_MODE_WT &&
new_pcm == _PAGE_CACHE_MODE_WC)) {
return 0;
}
return 1;
}
pmd_t *populate_extra_pmd(unsigned long vaddr);
pte_t *populate_extra_pte(unsigned long vaddr);
#ifdef CONFIG_MITIGATION_PAGE_TABLE_ISOLATION
pgd_t __pti_set_user_pgtbl(pgd_t *pgdp, pgd_t pgd);
/*
* Take a PGD location (pgdp) and a pgd value that needs to be set there.
* Populates the user and returns the resulting PGD that must be set in
* the kernel copy of the page tables.
*/
static inline pgd_t pti_set_user_pgtbl(pgd_t *pgdp, pgd_t pgd)
{
if (!static_cpu_has(X86_FEATURE_PTI))
return pgd;
return __pti_set_user_pgtbl(pgdp, pgd);
}
#else /* CONFIG_MITIGATION_PAGE_TABLE_ISOLATION */
static inline pgd_t pti_set_user_pgtbl(pgd_t *pgdp, pgd_t pgd)
{
return pgd;
}
#endif /* CONFIG_MITIGATION_PAGE_TABLE_ISOLATION */
#endif /* __ASSEMBLY__ */
#ifdef CONFIG_X86_32
# include <asm/pgtable_32.h>
#else
# include <asm/pgtable_64.h>
#endif
#ifndef __ASSEMBLY__
#include <linux/mm_types.h>
#include <linux/mmdebug.h>
#include <linux/log2.h>
#include <asm/fixmap.h>
static inline int pte_none(pte_t pte)
{
return !(pte.pte & ~(_PAGE_KNL_ERRATUM_MASK));
}
#define __HAVE_ARCH_PTE_SAME
static inline int pte_same(pte_t a, pte_t b)
{
return a.pte == b.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) - (nr << PFN_PTE_SHIFT));
return __pte(pte_val(pte) + (nr << PFN_PTE_SHIFT));
}
#define pte_advance_pfn pte_advance_pfn
static inline int pte_present(pte_t a)
{
return pte_flags(a) & (_PAGE_PRESENT | _PAGE_PROTNONE);
}
#ifdef CONFIG_ARCH_HAS_PTE_DEVMAP
static inline int pte_devmap(pte_t a)
{
return (pte_flags(a) & _PAGE_DEVMAP) == _PAGE_DEVMAP;
}
#endif
#define pte_accessible pte_accessible
static inline bool pte_accessible(struct mm_struct *mm, pte_t a)
{
if (pte_flags(a) & _PAGE_PRESENT)
return true;
if ((pte_flags(a) & _PAGE_PROTNONE) &&
atomic_read(&mm->tlb_flush_pending))
return true;
return false;
}
static inline int pmd_present(pmd_t pmd)
{
/*
* Checking for _PAGE_PSE is needed too because
* split_huge_page will temporarily clear the present bit (but
* the _PAGE_PSE flag will remain set at all times while the
* _PAGE_PRESENT bit is clear).
*/
return pmd_flags(pmd) & (_PAGE_PRESENT | _PAGE_PROTNONE | _PAGE_PSE);
}
#ifdef CONFIG_NUMA_BALANCING
/*
* These work without NUMA balancing but the kernel does not care. See the
* comment in include/linux/pgtable.h
*/
static inline int pte_protnone(pte_t pte)
{
return (pte_flags(pte) & (_PAGE_PROTNONE | _PAGE_PRESENT))
== _PAGE_PROTNONE;
}
static inline int pmd_protnone(pmd_t pmd)
{
return (pmd_flags(pmd) & (_PAGE_PROTNONE | _PAGE_PRESENT))