1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_X86_PGTABLE_H 3 #define _ASM_X86_PGTABLE_H 4 5 #include <linux/mem_encrypt.h> 6 #include <asm/page.h> 7 #include <asm/pgtable_types.h> 8 9 /* 10 * Macro to mark a page protection value as UC- 11 */ 12 #define pgprot_noncached(prot) \ 13 ((boot_cpu_data.x86 > 3) \ 14 ? (__pgprot(pgprot_val(prot) | \ 15 cachemode2protval(_PAGE_CACHE_MODE_UC_MINUS))) \ 16 : (prot)) 17 18 #ifndef __ASSEMBLY__ 19 #include <linux/spinlock.h> 20 #include <asm/x86_init.h> 21 #include <asm/pkru.h> 22 #include <asm/fpu/api.h> 23 #include <asm/coco.h> 24 #include <asm-generic/pgtable_uffd.h> 25 #include <linux/page_table_check.h> 26 27 extern pgd_t early_top_pgt[PTRS_PER_PGD]; 28 bool __init __early_make_pgtable(unsigned long address, pmdval_t pmd); 29 30 struct seq_file; 31 void ptdump_walk_pgd_level(struct seq_file *m, struct mm_struct *mm); 32 void ptdump_walk_pgd_level_debugfs(struct seq_file *m, struct mm_struct *mm, 33 bool user); 34 void ptdump_walk_pgd_level_checkwx(void); 35 void ptdump_walk_user_pgd_level_checkwx(void); 36 37 /* 38 * Macros to add or remove encryption attribute 39 */ 40 #define pgprot_encrypted(prot) __pgprot(cc_mkenc(pgprot_val(prot))) 41 #define pgprot_decrypted(prot) __pgprot(cc_mkdec(pgprot_val(prot))) 42 43 #ifdef CONFIG_DEBUG_WX 44 #define debug_checkwx() ptdump_walk_pgd_level_checkwx() 45 #define debug_checkwx_user() ptdump_walk_user_pgd_level_checkwx() 46 #else 47 #define debug_checkwx() do { } while (0) 48 #define debug_checkwx_user() do { } while (0) 49 #endif 50 51 /* 52 * ZERO_PAGE is a global shared page that is always zero: used 53 * for zero-mapped memory areas etc.. 54 */ 55 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] 56 __visible; 57 #define ZERO_PAGE(vaddr) ((void)(vaddr),virt_to_page(empty_zero_page)) 58 59 extern spinlock_t pgd_lock; 60 extern struct list_head pgd_list; 61 62 extern struct mm_struct *pgd_page_get_mm(struct page *page); 63 64 extern pmdval_t early_pmd_flags; 65 66 #ifdef CONFIG_PARAVIRT_XXL 67 #include <asm/paravirt.h> 68 #else /* !CONFIG_PARAVIRT_XXL */ 69 #define set_pte(ptep, pte) native_set_pte(ptep, pte) 70 71 #define set_pte_atomic(ptep, pte) \ 72 native_set_pte_atomic(ptep, pte) 73 74 #define set_pmd(pmdp, pmd) native_set_pmd(pmdp, pmd) 75 76 #ifndef __PAGETABLE_P4D_FOLDED 77 #define set_pgd(pgdp, pgd) native_set_pgd(pgdp, pgd) 78 #define pgd_clear(pgd) (pgtable_l5_enabled() ? native_pgd_clear(pgd) : 0) 79 #endif 80 81 #ifndef set_p4d 82 # define set_p4d(p4dp, p4d) native_set_p4d(p4dp, p4d) 83 #endif 84 85 #ifndef __PAGETABLE_PUD_FOLDED 86 #define p4d_clear(p4d) native_p4d_clear(p4d) 87 #endif 88 89 #ifndef set_pud 90 # define set_pud(pudp, pud) native_set_pud(pudp, pud) 91 #endif 92 93 #ifndef __PAGETABLE_PUD_FOLDED 94 #define pud_clear(pud) native_pud_clear(pud) 95 #endif 96 97 #define pte_clear(mm, addr, ptep) native_pte_clear(mm, addr, ptep) 98 #define pmd_clear(pmd) native_pmd_clear(pmd) 99 100 #define pgd_val(x) native_pgd_val(x) 101 #define __pgd(x) native_make_pgd(x) 102 103 #ifndef __PAGETABLE_P4D_FOLDED 104 #define p4d_val(x) native_p4d_val(x) 105 #define __p4d(x) native_make_p4d(x) 106 #endif 107 108 #ifndef __PAGETABLE_PUD_FOLDED 109 #define pud_val(x) native_pud_val(x) 110 #define __pud(x) native_make_pud(x) 111 #endif 112 113 #ifndef __PAGETABLE_PMD_FOLDED 114 #define pmd_val(x) native_pmd_val(x) 115 #define __pmd(x) native_make_pmd(x) 116 #endif 117 118 #define pte_val(x) native_pte_val(x) 119 #define __pte(x) native_make_pte(x) 120 121 #define arch_end_context_switch(prev) do {} while(0) 122 #endif /* CONFIG_PARAVIRT_XXL */ 123 124 /* 125 * The following only work if pte_present() is true. 126 * Undefined behaviour if not.. 127 */ 128 static inline bool pte_dirty(pte_t pte) 129 { 130 return pte_flags(pte) & _PAGE_DIRTY_BITS; 131 } 132 133 static inline bool pte_shstk(pte_t pte) 134 { 135 return cpu_feature_enabled(X86_FEATURE_SHSTK) && 136 (pte_flags(pte) & (_PAGE_RW | _PAGE_DIRTY)) == _PAGE_DIRTY; 137 } 138 139 static inline int pte_young(pte_t pte) 140 { 141 return pte_flags(pte) & _PAGE_ACCESSED; 142 } 143 144 static inline bool pmd_dirty(pmd_t pmd) 145 { 146 return pmd_flags(pmd) & _PAGE_DIRTY_BITS; 147 } 148 149 static inline bool pmd_shstk(pmd_t pmd) 150 { 151 return cpu_feature_enabled(X86_FEATURE_SHSTK) && 152 (pmd_flags(pmd) & (_PAGE_RW | _PAGE_DIRTY | _PAGE_PSE)) == 153 (_PAGE_DIRTY | _PAGE_PSE); 154 } 155 156 #define pmd_young pmd_young 157 static inline int pmd_young(pmd_t pmd) 158 { 159 return pmd_flags(pmd) & _PAGE_ACCESSED; 160 } 161 162 static inline bool pud_dirty(pud_t pud) 163 { 164 return pud_flags(pud) & _PAGE_DIRTY_BITS; 165 } 166 167 static inline int pud_young(pud_t pud) 168 { 169 return pud_flags(pud) & _PAGE_ACCESSED; 170 } 171 172 static inline int pte_write(pte_t pte) 173 { 174 /* 175 * Shadow stack pages are logically writable, but do not have 176 * _PAGE_RW. Check for them separately from _PAGE_RW itself. 177 */ 178 return (pte_flags(pte) & _PAGE_RW) || pte_shstk(pte); 179 } 180 181 #define pmd_write pmd_write 182 static inline int pmd_write(pmd_t pmd) 183 { 184 /* 185 * Shadow stack pages are logically writable, but do not have 186 * _PAGE_RW. Check for them separately from _PAGE_RW itself. 187 */ 188 return (pmd_flags(pmd) & _PAGE_RW) || pmd_shstk(pmd); 189 } 190 191 #define pud_write pud_write 192 static inline int pud_write(pud_t pud) 193 { 194 return pud_flags(pud) & _PAGE_RW; 195 } 196 197 static inline int pte_huge(pte_t pte) 198 { 199 return pte_flags(pte) & _PAGE_PSE; 200 } 201 202 static inline int pte_global(pte_t pte) 203 { 204 return pte_flags(pte) & _PAGE_GLOBAL; 205 } 206 207 static inline int pte_exec(pte_t pte) 208 { 209 return !(pte_flags(pte) & _PAGE_NX); 210 } 211 212 static inline int pte_special(pte_t pte) 213 { 214 return pte_flags(pte) & _PAGE_SPECIAL; 215 } 216 217 /* Entries that were set to PROT_NONE are inverted */ 218 219 static inline u64 protnone_mask(u64 val); 220 221 #define PFN_PTE_SHIFT PAGE_SHIFT 222 223 static inline unsigned long pte_pfn(pte_t pte) 224 { 225 phys_addr_t pfn = pte_val(pte); 226 pfn ^= protnone_mask(pfn); 227 return (pfn & PTE_PFN_MASK) >> PAGE_SHIFT; 228 } 229 230 static inline unsigned long pmd_pfn(pmd_t pmd) 231 { 232 phys_addr_t pfn = pmd_val(pmd); 233 pfn ^= protnone_mask(pfn); 234 return (pfn & pmd_pfn_mask(pmd)) >> PAGE_SHIFT; 235 } 236 237 static inline unsigned long pud_pfn(pud_t pud) 238 { 239 phys_addr_t pfn = pud_val(pud); 240 pfn ^= protnone_mask(pfn); 241 return (pfn & pud_pfn_mask(pud)) >> PAGE_SHIFT; 242 } 243 244 static inline unsigned long p4d_pfn(p4d_t p4d) 245 { 246 return (p4d_val(p4d) & p4d_pfn_mask(p4d)) >> PAGE_SHIFT; 247 } 248 249 static inline unsigned long pgd_pfn(pgd_t pgd) 250 { 251 return (pgd_val(pgd) & PTE_PFN_MASK) >> PAGE_SHIFT; 252 } 253 254 #define p4d_leaf p4d_large 255 static inline int p4d_large(p4d_t p4d) 256 { 257 /* No 512 GiB pages yet */ 258 return 0; 259 } 260 261 #define pte_page(pte) pfn_to_page(pte_pfn(pte)) 262 263 #define pmd_leaf pmd_large 264 static inline int pmd_large(pmd_t pte) 265 { 266 return pmd_flags(pte) & _PAGE_PSE; 267 } 268 269 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 270 /* NOTE: when predicate huge page, consider also pmd_devmap, or use pmd_large */ 271 static inline int pmd_trans_huge(pmd_t pmd) 272 { 273 return (pmd_val(pmd) & (_PAGE_PSE|_PAGE_DEVMAP)) == _PAGE_PSE; 274 } 275 276 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD 277 static inline int pud_trans_huge(pud_t pud) 278 { 279 return (pud_val(pud) & (_PAGE_PSE|_PAGE_DEVMAP)) == _PAGE_PSE; 280 } 281 #endif 282 283 #define has_transparent_hugepage has_transparent_hugepage 284 static inline int has_transparent_hugepage(void) 285 { 286 return boot_cpu_has(X86_FEATURE_PSE); 287 } 288 289 #ifdef CONFIG_ARCH_HAS_PTE_DEVMAP 290 static inline int pmd_devmap(pmd_t pmd) 291 { 292 return !!(pmd_val(pmd) & _PAGE_DEVMAP); 293 } 294 295 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD 296 static inline int pud_devmap(pud_t pud) 297 { 298 return !!(pud_val(pud) & _PAGE_DEVMAP); 299 } 300 #else 301 static inline int pud_devmap(pud_t pud) 302 { 303 return 0; 304 } 305 #endif 306 307 static inline int pgd_devmap(pgd_t pgd) 308 { 309 return 0; 310 } 311 #endif 312 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 313 314 static inline pte_t pte_set_flags(pte_t pte, pteval_t set) 315 { 316 pteval_t v = native_pte_val(pte); 317 318 return native_make_pte(v | set); 319 } 320 321 static inline pte_t pte_clear_flags(pte_t pte, pteval_t clear) 322 { 323 pteval_t v = native_pte_val(pte); 324 325 return native_make_pte(v & ~clear); 326 } 327 328 /* 329 * Write protection operations can result in Dirty=1,Write=0 PTEs. But in the 330 * case of X86_FEATURE_USER_SHSTK, these PTEs denote shadow stack memory. So 331 * when creating dirty, write-protected memory, a software bit is used: 332 * _PAGE_BIT_SAVED_DIRTY. The following functions take a PTE and transition the 333 * Dirty bit to SavedDirty, and vice-vesra. 334 * 335 * This shifting is only done if needed. In the case of shifting 336 * Dirty->SavedDirty, the condition is if the PTE is Write=0. In the case of 337 * shifting SavedDirty->Dirty, the condition is Write=1. 338 */ 339 static inline pgprotval_t mksaveddirty_shift(pgprotval_t v) 340 { 341 pgprotval_t cond = (~v >> _PAGE_BIT_RW) & 1; 342 343 v |= ((v >> _PAGE_BIT_DIRTY) & cond) << _PAGE_BIT_SAVED_DIRTY; 344 v &= ~(cond << _PAGE_BIT_DIRTY); 345 346 return v; 347 } 348 349 static inline pgprotval_t clear_saveddirty_shift(pgprotval_t v) 350 { 351 pgprotval_t cond = (v >> _PAGE_BIT_RW) & 1; 352 353 v |= ((v >> _PAGE_BIT_SAVED_DIRTY) & cond) << _PAGE_BIT_DIRTY; 354 v &= ~(cond << _PAGE_BIT_SAVED_DIRTY); 355 356 return v; 357 } 358 359 static inline pte_t pte_mksaveddirty(pte_t pte) 360 { 361 pteval_t v = native_pte_val(pte); 362 363 v = mksaveddirty_shift(v); 364 return native_make_pte(v); 365 } 366 367 static inline pte_t pte_clear_saveddirty(pte_t pte) 368 { 369 pteval_t v = native_pte_val(pte); 370 371 v = clear_saveddirty_shift(v); 372 return native_make_pte(v); 373 } 374 375 static inline pte_t pte_wrprotect(pte_t pte) 376 { 377 pte = pte_clear_flags(pte, _PAGE_RW); 378 379 /* 380 * Blindly clearing _PAGE_RW might accidentally create 381 * a shadow stack PTE (Write=0,Dirty=1). Move the hardware 382 * dirty value to the software bit, if present. 383 */ 384 return pte_mksaveddirty(pte); 385 } 386 387 #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP 388 static inline int pte_uffd_wp(pte_t pte) 389 { 390 return pte_flags(pte) & _PAGE_UFFD_WP; 391 } 392 393 static inline pte_t pte_mkuffd_wp(pte_t pte) 394 { 395 return pte_wrprotect(pte_set_flags(pte, _PAGE_UFFD_WP)); 396 } 397 398 static inline pte_t pte_clear_uffd_wp(pte_t pte) 399 { 400 return pte_clear_flags(pte, _PAGE_UFFD_WP); 401 } 402 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */ 403 404 static inline pte_t pte_mkclean(pte_t pte) 405 { 406 return pte_clear_flags(pte, _PAGE_DIRTY_BITS); 407 } 408 409 static inline pte_t pte_mkold(pte_t pte) 410 { 411 return pte_clear_flags(pte, _PAGE_ACCESSED); 412 } 413 414 static inline pte_t pte_mkexec(pte_t pte) 415 { 416 return pte_clear_flags(pte, _PAGE_NX); 417 } 418 419 static inline pte_t pte_mkdirty(pte_t pte) 420 { 421 pte = pte_set_flags(pte, _PAGE_DIRTY | _PAGE_SOFT_DIRTY); 422 423 return pte_mksaveddirty(pte); 424 } 425 426 static inline pte_t pte_mkwrite_shstk(pte_t pte) 427 { 428 pte = pte_clear_flags(pte, _PAGE_RW); 429 430 return pte_set_flags(pte, _PAGE_DIRTY); 431 } 432 433 static inline pte_t pte_mkyoung(pte_t pte) 434 { 435 return pte_set_flags(pte, _PAGE_ACCESSED); 436 } 437 438 static inline pte_t pte_mkwrite_novma(pte_t pte) 439 { 440 return pte_set_flags(pte, _PAGE_RW); 441 } 442 443 struct vm_area_struct; 444 pte_t pte_mkwrite(pte_t pte, struct vm_area_struct *vma); 445 #define pte_mkwrite pte_mkwrite 446 447 static inline pte_t pte_mkhuge(pte_t pte) 448 { 449 return pte_set_flags(pte, _PAGE_PSE); 450 } 451 452 static inline pte_t pte_clrhuge(pte_t pte) 453 { 454 return pte_clear_flags(pte, _PAGE_PSE); 455 } 456 457 static inline pte_t pte_mkglobal(pte_t pte) 458 { 459 return pte_set_flags(pte, _PAGE_GLOBAL); 460 } 461 462 static inline pte_t pte_clrglobal(pte_t pte) 463 { 464 return pte_clear_flags(pte, _PAGE_GLOBAL); 465 } 466 467 static inline pte_t pte_mkspecial(pte_t pte) 468 { 469 return pte_set_flags(pte, _PAGE_SPECIAL); 470 } 471 472 static inline pte_t pte_mkdevmap(pte_t pte) 473 { 474 return pte_set_flags(pte, _PAGE_SPECIAL|_PAGE_DEVMAP); 475 } 476 477 static inline pmd_t pmd_set_flags(pmd_t pmd, pmdval_t set) 478 { 479 pmdval_t v = native_pmd_val(pmd); 480 481 return native_make_pmd(v | set); 482 } 483 484 static inline pmd_t pmd_clear_flags(pmd_t pmd, pmdval_t clear) 485 { 486 pmdval_t v = native_pmd_val(pmd); 487 488 return native_make_pmd(v & ~clear); 489 } 490 491 /* See comments above mksaveddirty_shift() */ 492 static inline pmd_t pmd_mksaveddirty(pmd_t pmd) 493 { 494 pmdval_t v = native_pmd_val(pmd); 495 496 v = mksaveddirty_shift(v); 497 return native_make_pmd(v); 498 } 499 500 /* See comments above mksaveddirty_shift() */ 501 static inline pmd_t pmd_clear_saveddirty(pmd_t pmd) 502 { 503 pmdval_t v = native_pmd_val(pmd); 504 505 v = clear_saveddirty_shift(v); 506 return native_make_pmd(v); 507 } 508 509 static inline pmd_t pmd_wrprotect(pmd_t pmd) 510 { 511 pmd = pmd_clear_flags(pmd, _PAGE_RW); 512 513 /* 514 * Blindly clearing _PAGE_RW might accidentally create 515 * a shadow stack PMD (RW=0, Dirty=1). Move the hardware 516 * dirty value to the software bit. 517 */ 518 return pmd_mksaveddirty(pmd); 519 } 520 521 #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP 522 static inline int pmd_uffd_wp(pmd_t pmd) 523 { 524 return pmd_flags(pmd) & _PAGE_UFFD_WP; 525 } 526 527 static inline pmd_t pmd_mkuffd_wp(pmd_t pmd) 528 { 529 return pmd_wrprotect(pmd_set_flags(pmd, _PAGE_UFFD_WP)); 530 } 531 532 static inline pmd_t pmd_clear_uffd_wp(pmd_t pmd) 533 { 534 return pmd_clear_flags(pmd, _PAGE_UFFD_WP); 535 } 536 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */ 537 538 static inline pmd_t pmd_mkold(pmd_t pmd) 539 { 540 return pmd_clear_flags(pmd, _PAGE_ACCESSED); 541 } 542 543 static inline pmd_t pmd_mkclean(pmd_t pmd) 544 { 545 return pmd_clear_flags(pmd, _PAGE_DIRTY_BITS); 546 } 547 548 static inline pmd_t pmd_mkdirty(pmd_t pmd) 549 { 550 pmd = pmd_set_flags(pmd, _PAGE_DIRTY | _PAGE_SOFT_DIRTY); 551 552 return pmd_mksaveddirty(pmd); 553 } 554 555 static inline pmd_t pmd_mkwrite_shstk(pmd_t pmd) 556 { 557 pmd = pmd_clear_flags(pmd, _PAGE_RW); 558 559 return pmd_set_flags(pmd, _PAGE_DIRTY); 560 } 561 562 static inline pmd_t pmd_mkdevmap(pmd_t pmd) 563 { 564 return pmd_set_flags(pmd, _PAGE_DEVMAP); 565 } 566 567 static inline pmd_t pmd_mkhuge(pmd_t pmd) 568 { 569 return pmd_set_flags(pmd, _PAGE_PSE); 570 } 571 572 static inline pmd_t pmd_mkyoung(pmd_t pmd) 573 { 574 return pmd_set_flags(pmd, _PAGE_ACCESSED); 575 } 576 577 static inline pmd_t pmd_mkwrite_novma(pmd_t pmd) 578 { 579 return pmd_set_flags(pmd, _PAGE_RW); 580 } 581 582 pmd_t pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma); 583 #define pmd_mkwrite pmd_mkwrite 584 585 static inline pud_t pud_set_flags(pud_t pud, pudval_t set) 586 { 587 pudval_t v = native_pud_val(pud); 588 589 return native_make_pud(v | set); 590 } 591 592 static inline pud_t pud_clear_flags(pud_t pud, pudval_t clear) 593 { 594 pudval_t v = native_pud_val(pud); 595 596 return native_make_pud(v & ~clear); 597 } 598 599 /* See comments above mksaveddirty_shift() */ 600 static inline pud_t pud_mksaveddirty(pud_t pud) 601 { 602 pudval_t v = native_pud_val(pud); 603 604 v = mksaveddirty_shift(v); 605 return native_make_pud(v); 606 } 607 608 /* See comments above mksaveddirty_shift() */ 609 static inline pud_t pud_clear_saveddirty(pud_t pud) 610 { 611 pudval_t v = native_pud_val(pud); 612 613 v = clear_saveddirty_shift(v); 614 return native_make_pud(v); 615 } 616 617 static inline pud_t pud_mkold(pud_t pud) 618 { 619 return pud_clear_flags(pud, _PAGE_ACCESSED); 620 } 621 622 static inline pud_t pud_mkclean(pud_t pud) 623 { 624 return pud_clear_flags(pud, _PAGE_DIRTY_BITS); 625 } 626 627 static inline pud_t pud_wrprotect(pud_t pud) 628 { 629 pud = pud_clear_flags(pud, _PAGE_RW); 630 631 /* 632 * Blindly clearing _PAGE_RW might accidentally create 633 * a shadow stack PUD (RW=0, Dirty=1). Move the hardware 634 * dirty value to the software bit. 635 */ 636 return pud_mksaveddirty(pud); 637 } 638 639 static inline pud_t pud_mkdirty(pud_t pud) 640 { 641 pud = pud_set_flags(pud, _PAGE_DIRTY | _PAGE_SOFT_DIRTY); 642 643 return pud_mksaveddirty(pud); 644 } 645 646 static inline pud_t pud_mkdevmap(pud_t pud) 647 { 648 return pud_set_flags(pud, _PAGE_DEVMAP); 649 } 650 651 static inline pud_t pud_mkhuge(pud_t pud) 652 { 653 return pud_set_flags(pud, _PAGE_PSE); 654 } 655 656 static inline pud_t pud_mkyoung(pud_t pud) 657 { 658 return pud_set_flags(pud, _PAGE_ACCESSED); 659 } 660 661 static inline pud_t pud_mkwrite(pud_t pud) 662 { 663 pud = pud_set_flags(pud, _PAGE_RW); 664 665 return pud_clear_saveddirty(pud); 666 } 667 668 #ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY 669 static inline int pte_soft_dirty(pte_t pte) 670 { 671 return pte_flags(pte) & _PAGE_SOFT_DIRTY; 672 } 673 674 static inline int pmd_soft_dirty(pmd_t pmd) 675 { 676 return pmd_flags(pmd) & _PAGE_SOFT_DIRTY; 677 } 678 679 static inline int pud_soft_dirty(pud_t pud) 680 { 681 return pud_flags(pud) & _PAGE_SOFT_DIRTY; 682 } 683 684 static inline pte_t pte_mksoft_dirty(pte_t pte) 685 { 686 return pte_set_flags(pte, _PAGE_SOFT_DIRTY); 687 } 688 689 static inline pmd_t pmd_mksoft_dirty(pmd_t pmd) 690 { 691 return pmd_set_flags(pmd, _PAGE_SOFT_DIRTY); 692 } 693 694 static inline pud_t pud_mksoft_dirty(pud_t pud) 695 { 696 return pud_set_flags(pud, _PAGE_SOFT_DIRTY); 697 } 698 699 static inline pte_t pte_clear_soft_dirty(pte_t pte) 700 { 701 return pte_clear_flags(pte, _PAGE_SOFT_DIRTY); 702 } 703 704 static inline pmd_t pmd_clear_soft_dirty(pmd_t pmd) 705 { 706 return pmd_clear_flags(pmd, _PAGE_SOFT_DIRTY); 707 } 708 709 static inline pud_t pud_clear_soft_dirty(pud_t pud) 710 { 711 return pud_clear_flags(pud, _PAGE_SOFT_DIRTY); 712 } 713 714 #endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */ 715 716 /* 717 * Mask out unsupported bits in a present pgprot. Non-present pgprots 718 * can use those bits for other purposes, so leave them be. 719 */ 720 static inline pgprotval_t massage_pgprot(pgprot_t pgprot) 721 { 722 pgprotval_t protval = pgprot_val(pgprot); 723 724 if (protval & _PAGE_PRESENT) 725 protval &= __supported_pte_mask; 726 727 return protval; 728 } 729 730 static inline pgprotval_t check_pgprot(pgprot_t pgprot) 731 { 732 pgprotval_t massaged_val = massage_pgprot(pgprot); 733 734 /* mmdebug.h can not be included here because of dependencies */ 735 #ifdef CONFIG_DEBUG_VM 736 WARN_ONCE(pgprot_val(pgprot) != massaged_val, 737 "attempted to set unsupported pgprot: %016llx " 738 "bits: %016llx supported: %016llx\n", 739 (u64)pgprot_val(pgprot), 740 (u64)pgprot_val(pgprot) ^ massaged_val, 741 (u64)__supported_pte_mask); 742 #endif 743 744 return massaged_val; 745 } 746 747 static inline pte_t pfn_pte(unsigned long page_nr, pgprot_t pgprot) 748 { 749 phys_addr_t pfn = (phys_addr_t)page_nr << PAGE_SHIFT; 750 pfn ^= protnone_mask(pgprot_val(pgprot)); 751 pfn &= PTE_PFN_MASK; 752 return __pte(pfn | check_pgprot(pgprot)); 753 } 754 755 static inline pmd_t pfn_pmd(unsigned long page_nr, pgprot_t pgprot) 756 { 757 phys_addr_t pfn = (phys_addr_t)page_nr << PAGE_SHIFT; 758 pfn ^= protnone_mask(pgprot_val(pgprot)); 759 pfn &= PHYSICAL_PMD_PAGE_MASK; 760 return __pmd(pfn | check_pgprot(pgprot)); 761 } 762 763 static inline pud_t pfn_pud(unsigned long page_nr, pgprot_t pgprot) 764 { 765 phys_addr_t pfn = (phys_addr_t)page_nr << PAGE_SHIFT; 766 pfn ^= protnone_mask(pgprot_val(pgprot)); 767 pfn &= PHYSICAL_PUD_PAGE_MASK; 768 return __pud(pfn | check_pgprot(pgprot)); 769 } 770 771 static inline pmd_t pmd_mkinvalid(pmd_t pmd) 772 { 773 return pfn_pmd(pmd_pfn(pmd), 774 __pgprot(pmd_flags(pmd) & ~(_PAGE_PRESENT|_PAGE_PROTNONE))); 775 } 776 777 static inline u64 flip_protnone_guard(u64 oldval, u64 val, u64 mask); 778 779 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) 780 { 781 pteval_t val = pte_val(pte), oldval = val; 782 pte_t pte_result; 783 784 /* 785 * Chop off the NX bit (if present), and add the NX portion of 786 * the newprot (if present): 787 */ 788 val &= _PAGE_CHG_MASK; 789 val |= check_pgprot(newprot) & ~_PAGE_CHG_MASK; 790 val = flip_protnone_guard(oldval, val, PTE_PFN_MASK); 791 792 pte_result = __pte(val); 793 794 /* 795 * To avoid creating Write=0,Dirty=1 PTEs, pte_modify() needs to avoid: 796 * 1. Marking Write=0 PTEs Dirty=1 797 * 2. Marking Dirty=1 PTEs Write=0 798 * 799 * The first case cannot happen because the _PAGE_CHG_MASK will filter 800 * out any Dirty bit passed in newprot. Handle the second case by 801 * going through the mksaveddirty exercise. Only do this if the old 802 * value was Write=1 to avoid doing this on Shadow Stack PTEs. 803 */ 804 if (oldval & _PAGE_RW) 805 pte_result = pte_mksaveddirty(pte_result); 806 else 807 pte_result = pte_clear_saveddirty(pte_result); 808 809 return pte_result; 810 } 811 812 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot) 813 { 814 pmdval_t val = pmd_val(pmd), oldval = val; 815 pmd_t pmd_result; 816 817 val &= (_HPAGE_CHG_MASK & ~_PAGE_DIRTY); 818 val |= check_pgprot(newprot) & ~_HPAGE_CHG_MASK; 819 val = flip_protnone_guard(oldval, val, PHYSICAL_PMD_PAGE_MASK); 820 821 pmd_result = __pmd(val); 822 823 /* 824 * To avoid creating Write=0,Dirty=1 PMDs, pte_modify() needs to avoid: 825 * 1. Marking Write=0 PMDs Dirty=1 826 * 2. Marking Dirty=1 PMDs Write=0 827 * 828 * The first case cannot happen because the _PAGE_CHG_MASK will filter 829 * out any Dirty bit passed in newprot. Handle the second case by 830 * going through the mksaveddirty exercise. Only do this if the old 831 * value was Write=1 to avoid doing this on Shadow Stack PTEs. 832 */ 833 if (oldval & _PAGE_RW) 834 pmd_result = pmd_mksaveddirty(pmd_result); 835 else 836 pmd_result = pmd_clear_saveddirty(pmd_result); 837 838 return pmd_result; 839 } 840 841 /* 842 * mprotect needs to preserve PAT and encryption bits when updating 843 * vm_page_prot 844 */ 845 #define pgprot_modify pgprot_modify 846 static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot) 847 { 848 pgprotval_t preservebits = pgprot_val(oldprot) & _PAGE_CHG_MASK; 849 pgprotval_t addbits = pgprot_val(newprot) & ~_PAGE_CHG_MASK; 850 return __pgprot(preservebits | addbits); 851 } 852 853 #define pte_pgprot(x) __pgprot(pte_flags(x)) 854 #define pmd_pgprot(x) __pgprot(pmd_flags(x)) 855 #define pud_pgprot(x) __pgprot(pud_flags(x)) 856 #define p4d_pgprot(x) __pgprot(p4d_flags(x)) 857 858 #define canon_pgprot(p) __pgprot(massage_pgprot(p)) 859 860 static inline int is_new_memtype_allowed(u64 paddr, unsigned long size, 861 enum page_cache_mode pcm, 862 enum page_cache_mode new_pcm) 863 { 864 /* 865 * PAT type is always WB for untracked ranges, so no need to check. 866 */ 867 if (x86_platform.is_untracked_pat_range(paddr, paddr + size)) 868 return 1; 869 870 /* 871 * Certain new memtypes are not allowed with certain 872 * requested memtype: 873 * - request is uncached, return cannot be write-back 874 * - request is write-combine, return cannot be write-back 875 * - request is write-through, return cannot be write-back 876 * - request is write-through, return cannot be write-combine 877 */ 878 if ((pcm == _PAGE_CACHE_MODE_UC_MINUS && 879 new_pcm == _PAGE_CACHE_MODE_WB) || 880 (pcm == _PAGE_CACHE_MODE_WC && 881 new_pcm == _PAGE_CACHE_MODE_WB) || 882 (pcm == _PAGE_CACHE_MODE_WT && 883 new_pcm == _PAGE_CACHE_MODE_WB) || 884 (pcm == _PAGE_CACHE_MODE_WT && 885 new_pcm == _PAGE_CACHE_MODE_WC)) { 886 return 0; 887 } 888 889 return 1; 890 } 891 892 pmd_t *populate_extra_pmd(unsigned long vaddr); 893 pte_t *populate_extra_pte(unsigned long vaddr); 894 895 #ifdef CONFIG_PAGE_TABLE_ISOLATION 896 pgd_t __pti_set_user_pgtbl(pgd_t *pgdp, pgd_t pgd); 897 898 /* 899 * Take a PGD location (pgdp) and a pgd value that needs to be set there. 900 * Populates the user and returns the resulting PGD that must be set in 901 * the kernel copy of the page tables. 902 */ 903 static inline pgd_t pti_set_user_pgtbl(pgd_t *pgdp, pgd_t pgd) 904 { 905 if (!static_cpu_has(X86_FEATURE_PTI)) 906 return pgd; 907 return __pti_set_user_pgtbl(pgdp, pgd); 908 } 909 #else /* CONFIG_PAGE_TABLE_ISOLATION */ 910 static inline pgd_t pti_set_user_pgtbl(pgd_t *pgdp, pgd_t pgd) 911 { 912 return pgd; 913 } 914 #endif /* CONFIG_PAGE_TABLE_ISOLATION */ 915 916 #endif /* __ASSEMBLY__ */ 917 918 919 #ifdef CONFIG_X86_32 920 # include <asm/pgtable_32.h> 921 #else 922 # include <asm/pgtable_64.h> 923 #endif 924 925 #ifndef __ASSEMBLY__ 926 #include <linux/mm_types.h> 927 #include <linux/mmdebug.h> 928 #include <linux/log2.h> 929 #include <asm/fixmap.h> 930 931 static inline int pte_none(pte_t pte) 932 { 933 return !(pte.pte & ~(_PAGE_KNL_ERRATUM_MASK)); 934 } 935 936 #define __HAVE_ARCH_PTE_SAME 937 static inline int pte_same(pte_t a, pte_t b) 938 { 939 return a.pte == b.pte; 940 } 941 942 static inline pte_t pte_next_pfn(pte_t pte) 943 { 944 if (__pte_needs_invert(pte_val(pte))) 945 return __pte(pte_val(pte) - (1UL << PFN_PTE_SHIFT)); 946 return __pte(pte_val(pte) + (1UL << PFN_PTE_SHIFT)); 947 } 948 #define pte_next_pfn pte_next_pfn 949 950 static inline int pte_present(pte_t a) 951 { 952 return pte_flags(a) & (_PAGE_PRESENT | _PAGE_PROTNONE); 953 } 954 955 #ifdef CONFIG_ARCH_HAS_PTE_DEVMAP 956 static inline int pte_devmap(pte_t a) 957 { 958 return (pte_flags(a) & _PAGE_DEVMAP) == _PAGE_DEVMAP; 959 } 960 #endif 961 962 #define pte_accessible pte_accessible 963 static inline bool pte_accessible(struct mm_struct *mm, pte_t a) 964 { 965 if (pte_flags(a) & _PAGE_PRESENT) 966 return true; 967 968 if ((pte_flags(a) & _PAGE_PROTNONE) && 969 atomic_read(&mm->tlb_flush_pending)) 970 return true; 971 972 return false; 973 } 974 975 static inline int pmd_present(pmd_t pmd) 976 { 977 /* 978 * Checking for _PAGE_PSE is needed too because 979 * split_huge_page will temporarily clear the present bit (but 980 * the _PAGE_PSE flag will remain set at all times while the 981 * _PAGE_PRESENT bit is clear). 982 */ 983 return pmd_flags(pmd) & (_PAGE_PRESENT | _PAGE_PROTNONE | _PAGE_PSE); 984 } 985 986 #ifdef CONFIG_NUMA_BALANCING 987 /* 988 * These work without NUMA balancing but the kernel does not care. See the 989 * comment in include/linux/pgtable.h 990 */ 991 static inline int pte_protnone(pte_t pte) 992 { 993 return (pte_flags(pte) & (_PAGE_PROTNONE | _PAGE_PRESENT)) 994 == _PAGE_PROTNONE; 995 } 996 997 static inline int pmd_protnone(pmd_t pmd) 998 { 999 return (pmd_flags(pmd) & (_PAGE_PROTNONE | _PAGE_PRESENT)) 1000 == _PAGE_PROTNONE; 1001 } 1002 #endif /* CONFIG_NUMA_BALANCING */ 1003 1004 static inline int pmd_none(pmd_t pmd) 1005 { 1006 /* Only check low word on 32-bit platforms, since it might be 1007 out of sync with upper half. */ 1008 unsigned long val = native_pmd_val(pmd); 1009 return (val & ~_PAGE_KNL_ERRATUM_MASK) == 0; 1010 } 1011 1012 static inline unsigned long pmd_page_vaddr(pmd_t pmd) 1013 { 1014 return (unsigned long)__va(pmd_val(pmd) & pmd_pfn_mask(pmd)); 1015 } 1016 1017 /* 1018 * Currently stuck as a macro due to indirect forward reference to 1019 * linux/mmzone.h's __section_mem_map_addr() definition: 1020 */ 1021 #define pmd_page(pmd) pfn_to_page(pmd_pfn(pmd)) 1022 1023 /* 1024 * Conversion functions: convert a page and protection to a page entry, 1025 * and a page entry and page directory to the page they refer to. 1026 * 1027 * (Currently stuck as a macro because of indirect forward reference 1028 * to linux/mm.h:page_to_nid()) 1029 */ 1030 #define mk_pte(page, pgprot) \ 1031 ({ \ 1032 pgprot_t __pgprot = pgprot; \ 1033 \ 1034 WARN_ON_ONCE((pgprot_val(__pgprot) & (_PAGE_DIRTY | _PAGE_RW)) == \ 1035 _PAGE_DIRTY); \ 1036 pfn_pte(page_to_pfn(page), __pgprot); \ 1037 }) 1038 1039 static inline int pmd_bad(pmd_t pmd) 1040 { 1041 return (pmd_flags(pmd) & ~(_PAGE_USER | _PAGE_ACCESSED)) != 1042 (_KERNPG_TABLE & ~_PAGE_ACCESSED); 1043 } 1044 1045 static inline unsigned long pages_to_mb(unsigned long npg) 1046 { 1047 return npg >> (20 - PAGE_SHIFT); 1048 } 1049 1050 #if CONFIG_PGTABLE_LEVELS > 2 1051 static inline int pud_none(pud_t pud) 1052 { 1053 return (native_pud_val(pud) & ~(_PAGE_KNL_ERRATUM_MASK)) == 0; 1054 } 1055 1056 static inline int pud_present(pud_t pud) 1057 { 1058 return pud_flags(pud) & _PAGE_PRESENT; 1059 } 1060 1061 static inline pmd_t *pud_pgtable(pud_t pud) 1062 { 1063 return (pmd_t *)__va(pud_val(pud) & pud_pfn_mask(pud)); 1064 } 1065 1066 /* 1067 * Currently stuck as a macro due to indirect forward reference to 1068 * linux/mmzone.h's __section_mem_map_addr() definition: 1069 */ 1070 #define pud_page(pud) pfn_to_page(pud_pfn(pud)) 1071 1072 #define pud_leaf pud_large 1073 static inline int pud_large(pud_t pud) 1074 { 1075 return (pud_val(pud) & (_PAGE_PSE | _PAGE_PRESENT)) == 1076 (_PAGE_PSE | _PAGE_PRESENT); 1077 } 1078 1079 static inline int pud_bad(pud_t pud) 1080 { 1081 return (pud_flags(pud) & ~(_KERNPG_TABLE | _PAGE_USER)) != 0; 1082 } 1083 #else 1084 #define pud_leaf pud_large 1085 static inline int pud_large(pud_t pud) 1086 { 1087 return 0; 1088 } 1089 #endif /* CONFIG_PGTABLE_LEVELS > 2 */ 1090 1091 #if CONFIG_PGTABLE_LEVELS > 3 1092 static inline int p4d_none(p4d_t p4d) 1093 { 1094 return (native_p4d_val(p4d) & ~(_PAGE_KNL_ERRATUM_MASK)) == 0; 1095 } 1096 1097 static inline int p4d_present(p4d_t p4d) 1098 { 1099 return p4d_flags(p4d) & _PAGE_PRESENT; 1100 } 1101 1102 static inline pud_t *p4d_pgtable(p4d_t p4d) 1103 { 1104 return (pud_t *)__va(p4d_val(p4d) & p4d_pfn_mask(p4d)); 1105 } 1106 1107 /* 1108 * Currently stuck as a macro due to indirect forward reference to 1109 * linux/mmzone.h's __section_mem_map_addr() definition: 1110 */ 1111 #define p4d_page(p4d) pfn_to_page(p4d_pfn(p4d)) 1112 1113 static inline int p4d_bad(p4d_t p4d) 1114 { 1115 unsigned long ignore_flags = _KERNPG_TABLE | _PAGE_USER; 1116 1117 if (IS_ENABLED(CONFIG_PAGE_TABLE_ISOLATION)) 1118 ignore_flags |= _PAGE_NX; 1119 1120 return (p4d_flags(p4d) & ~ignore_flags) != 0; 1121 } 1122 #endif /* CONFIG_PGTABLE_LEVELS > 3 */ 1123 1124 static inline unsigned long p4d_index(unsigned long address) 1125 { 1126 return (address >> P4D_SHIFT) & (PTRS_PER_P4D - 1); 1127 } 1128 1129 #if CONFIG_PGTABLE_LEVELS > 4 1130 static inline int pgd_present(pgd_t pgd) 1131 { 1132 if (!pgtable_l5_enabled()) 1133 return 1; 1134 return pgd_flags(pgd) & _PAGE_PRESENT; 1135 } 1136 1137 static inline unsigned long pgd_page_vaddr(pgd_t pgd) 1138 { 1139 return (unsigned long)__va((unsigned long)pgd_val(pgd) & PTE_PFN_MASK); 1140 } 1141 1142 /* 1143 * Currently stuck as a macro due to indirect forward reference to 1144 * linux/mmzone.h's __section_mem_map_addr() definition: 1145 */ 1146 #define pgd_page(pgd) pfn_to_page(pgd_pfn(pgd)) 1147 1148 /* to find an entry in a page-table-directory. */ 1149 static inline p4d_t *p4d_offset(pgd_t *pgd, unsigned long address) 1150 { 1151 if (!pgtable_l5_enabled()) 1152 return (p4d_t *)pgd; 1153 return (p4d_t *)pgd_page_vaddr(*pgd) + p4d_index(address); 1154 } 1155 1156 static inline int pgd_bad(pgd_t pgd) 1157 { 1158 unsigned long ignore_flags = _PAGE_USER; 1159 1160 if (!pgtable_l5_enabled()) 1161 return 0; 1162 1163 if (IS_ENABLED(CONFIG_PAGE_TABLE_ISOLATION)) 1164 ignore_flags |= _PAGE_NX; 1165 1166 return (pgd_flags(pgd) & ~ignore_flags) != _KERNPG_TABLE; 1167 } 1168 1169 static inline int pgd_none(pgd_t pgd) 1170 { 1171 if (!pgtable_l5_enabled()) 1172 return 0; 1173 /* 1174 * There is no need to do a workaround for the KNL stray 1175 * A/D bit erratum here. PGDs only point to page tables 1176 * except on 32-bit non-PAE which is not supported on 1177 * KNL. 1178 */ 1179 return !native_pgd_val(pgd); 1180 } 1181 #endif /* CONFIG_PGTABLE_LEVELS > 4 */ 1182 1183 #endif /* __ASSEMBLY__ */ 1184 1185 #define KERNEL_PGD_BOUNDARY pgd_index(PAGE_OFFSET) 1186 #define KERNEL_PGD_PTRS (PTRS_PER_PGD - KERNEL_PGD_BOUNDARY) 1187 1188 #ifndef __ASSEMBLY__ 1189 1190 extern int direct_gbpages; 1191 void init_mem_mapping(void); 1192 void early_alloc_pgt_buf(void); 1193 extern void memblock_find_dma_reserve(void); 1194 void __init poking_init(void); 1195 unsigned long init_memory_mapping(unsigned long start, 1196 unsigned long end, pgprot_t prot); 1197 1198 #ifdef CONFIG_X86_64 1199 extern pgd_t trampoline_pgd_entry; 1200 #endif 1201 1202 /* local pte updates need not use xchg for locking */ 1203 static inline pte_t native_local_ptep_get_and_clear(pte_t *ptep) 1204 { 1205 pte_t res = *ptep; 1206 1207 /* Pure native function needs no input for mm, addr */ 1208 native_pte_clear(NULL, 0, ptep); 1209 return res; 1210 } 1211 1212 static inline pmd_t native_local_pmdp_get_and_clear(pmd_t *pmdp) 1213 { 1214 pmd_t res = *pmdp; 1215 1216 native_pmd_clear(pmdp); 1217 return res; 1218 } 1219 1220 static inline pud_t native_local_pudp_get_and_clear(pud_t *pudp) 1221 { 1222 pud_t res = *pudp; 1223 1224 native_pud_clear(pudp); 1225 return res; 1226 } 1227 1228 static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr, 1229 pmd_t *pmdp, pmd_t pmd) 1230 { 1231 page_table_check_pmd_set(mm, pmdp, pmd); 1232 set_pmd(pmdp, pmd); 1233 } 1234 1235 static inline void set_pud_at(struct mm_struct *mm, unsigned long addr, 1236 pud_t *pudp, pud_t pud) 1237 { 1238 page_table_check_pud_set(mm, pudp, pud); 1239 native_set_pud(pudp, pud); 1240 } 1241 1242 /* 1243 * We only update the dirty/accessed state if we set 1244 * the dirty bit by hand in the kernel, since the hardware 1245 * will do the accessed bit for us, and we don't want to 1246 * race with other CPU's that might be updating the dirty 1247 * bit at the same time. 1248 */ 1249 struct vm_area_struct; 1250 1251 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS 1252 extern int ptep_set_access_flags(struct vm_area_struct *vma, 1253 unsigned long address, pte_t *ptep, 1254 pte_t entry, int dirty); 1255 1256 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG 1257 extern int ptep_test_and_clear_young(struct vm_area_struct *vma, 1258 unsigned long addr, pte_t *ptep); 1259 1260 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH 1261 extern int ptep_clear_flush_young(struct vm_area_struct *vma, 1262 unsigned long address, pte_t *ptep); 1263 1264 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR 1265 static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, 1266 pte_t *ptep) 1267 { 1268 pte_t pte = native_ptep_get_and_clear(ptep); 1269 page_table_check_pte_clear(mm, pte); 1270 return pte; 1271 } 1272 1273 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL 1274 static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm, 1275 unsigned long addr, pte_t *ptep, 1276 int full) 1277 { 1278 pte_t pte; 1279 if (full) { 1280 /* 1281 * Full address destruction in progress; paravirt does not 1282 * care about updates and native needs no locking 1283 */ 1284 pte = native_local_ptep_get_and_clear(ptep); 1285 page_table_check_pte_clear(mm, pte); 1286 } else { 1287 pte = ptep_get_and_clear(mm, addr, ptep); 1288 } 1289 return pte; 1290 } 1291 1292 #define __HAVE_ARCH_PTEP_SET_WRPROTECT 1293 static inline void ptep_set_wrprotect(struct mm_struct *mm, 1294 unsigned long addr, pte_t *ptep) 1295 { 1296 /* 1297 * Avoid accidentally creating shadow stack PTEs 1298 * (Write=0,Dirty=1). Use cmpxchg() to prevent races with 1299 * the hardware setting Dirty=1. 1300 */ 1301 pte_t old_pte, new_pte; 1302 1303 old_pte = READ_ONCE(*ptep); 1304 do { 1305 new_pte = pte_wrprotect(old_pte); 1306 } while (!try_cmpxchg((long *)&ptep->pte, (long *)&old_pte, *(long *)&new_pte)); 1307 } 1308 1309 #define flush_tlb_fix_spurious_fault(vma, address, ptep) do { } while (0) 1310 1311 #define mk_pmd(page, pgprot) pfn_pmd(page_to_pfn(page), (pgprot)) 1312 1313 #define __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS 1314 extern int pmdp_set_access_flags(struct vm_area_struct *vma, 1315 unsigned long address, pmd_t *pmdp, 1316 pmd_t entry, int dirty); 1317 extern int pudp_set_access_flags(struct vm_area_struct *vma, 1318 unsigned long address, pud_t *pudp, 1319 pud_t entry, int dirty); 1320 1321 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG 1322 extern int pmdp_test_and_clear_young(struct vm_area_struct *vma, 1323 unsigned long addr, pmd_t *pmdp); 1324 extern int pudp_test_and_clear_young(struct vm_area_struct *vma, 1325 unsigned long addr, pud_t *pudp); 1326 1327 #define __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH 1328 extern int pmdp_clear_flush_young(struct vm_area_struct *vma, 1329 unsigned long address, pmd_t *pmdp); 1330 1331 1332 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR 1333 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm, unsigned long addr, 1334 pmd_t *pmdp) 1335 { 1336 pmd_t pmd = native_pmdp_get_and_clear(pmdp); 1337 1338 page_table_check_pmd_clear(mm, pmd); 1339 1340 return pmd; 1341 } 1342 1343 #define __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR 1344 static inline pud_t pudp_huge_get_and_clear(struct mm_struct *mm, 1345 unsigned long addr, pud_t *pudp) 1346 { 1347 pud_t pud = native_pudp_get_and_clear(pudp); 1348 1349 page_table_check_pud_clear(mm, pud); 1350 1351 return pud; 1352 } 1353 1354 #define __HAVE_ARCH_PMDP_SET_WRPROTECT 1355 static inline void pmdp_set_wrprotect(struct mm_struct *mm, 1356 unsigned long addr, pmd_t *pmdp) 1357 { 1358 /* 1359 * Avoid accidentally creating shadow stack PTEs 1360 * (Write=0,Dirty=1). Use cmpxchg() to prevent races with 1361 * the hardware setting Dirty=1. 1362 */ 1363 pmd_t old_pmd, new_pmd; 1364 1365 old_pmd = READ_ONCE(*pmdp); 1366 do { 1367 new_pmd = pmd_wrprotect(old_pmd); 1368 } while (!try_cmpxchg((long *)pmdp, (long *)&old_pmd, *(long *)&new_pmd)); 1369 } 1370 1371 #ifndef pmdp_establish 1372 #define pmdp_establish pmdp_establish 1373 static inline pmd_t pmdp_establish(struct vm_area_struct *vma, 1374 unsigned long address, pmd_t *pmdp, pmd_t pmd) 1375 { 1376 page_table_check_pmd_set(vma->vm_mm, pmdp, pmd); 1377 if (IS_ENABLED(CONFIG_SMP)) { 1378 return xchg(pmdp, pmd); 1379 } else { 1380 pmd_t old = *pmdp; 1381 WRITE_ONCE(*pmdp, pmd); 1382 return old; 1383 } 1384 } 1385 #endif 1386 1387 #define __HAVE_ARCH_PMDP_INVALIDATE_AD 1388 extern pmd_t pmdp_invalidate_ad(struct vm_area_struct *vma, 1389 unsigned long address, pmd_t *pmdp); 1390 1391 /* 1392 * Page table pages are page-aligned. The lower half of the top 1393 * level is used for userspace and the top half for the kernel. 1394 * 1395 * Returns true for parts of the PGD that map userspace and 1396 * false for the parts that map the kernel. 1397 */ 1398 static inline bool pgdp_maps_userspace(void *__ptr) 1399 { 1400 unsigned long ptr = (unsigned long)__ptr; 1401 1402 return (((ptr & ~PAGE_MASK) / sizeof(pgd_t)) < PGD_KERNEL_START); 1403 } 1404 1405 #define pgd_leaf pgd_large 1406 static inline int pgd_large(pgd_t pgd) { return 0; } 1407 1408 #ifdef CONFIG_PAGE_TABLE_ISOLATION 1409 /* 1410 * All top-level PAGE_TABLE_ISOLATION page tables are order-1 pages 1411 * (8k-aligned and 8k in size). The kernel one is at the beginning 4k and 1412 * the user one is in the last 4k. To switch between them, you 1413 * just need to flip the 12th bit in their addresses. 1414 */ 1415 #define PTI_PGTABLE_SWITCH_BIT PAGE_SHIFT 1416 1417 /* 1418 * This generates better code than the inline assembly in 1419 * __set_bit(). 1420 */ 1421 static inline void *ptr_set_bit(void *ptr, int bit) 1422 { 1423 unsigned long __ptr = (unsigned long)ptr; 1424 1425 __ptr |= BIT(bit); 1426 return (void *)__ptr; 1427 } 1428 static inline void *ptr_clear_bit(void *ptr, int bit) 1429 { 1430 unsigned long __ptr = (unsigned long)ptr; 1431 1432 __ptr &= ~BIT(bit); 1433 return (void *)__ptr; 1434 } 1435 1436 static inline pgd_t *kernel_to_user_pgdp(pgd_t *pgdp) 1437 { 1438 return ptr_set_bit(pgdp, PTI_PGTABLE_SWITCH_BIT); 1439 } 1440 1441 static inline pgd_t *user_to_kernel_pgdp(pgd_t *pgdp) 1442 { 1443 return ptr_clear_bit(pgdp, PTI_PGTABLE_SWITCH_BIT); 1444 } 1445 1446 static inline p4d_t *kernel_to_user_p4dp(p4d_t *p4dp) 1447 { 1448 return ptr_set_bit(p4dp, PTI_PGTABLE_SWITCH_BIT); 1449 } 1450 1451 static inline p4d_t *user_to_kernel_p4dp(p4d_t *p4dp) 1452 { 1453 return ptr_clear_bit(p4dp, PTI_PGTABLE_SWITCH_BIT); 1454 } 1455 #endif /* CONFIG_PAGE_TABLE_ISOLATION */ 1456 1457 /* 1458 * clone_pgd_range(pgd_t *dst, pgd_t *src, int count); 1459 * 1460 * dst - pointer to pgd range anywhere on a pgd page 1461 * src - "" 1462 * count - the number of pgds to copy. 1463 * 1464 * dst and src can be on the same page, but the range must not overlap, 1465 * and must not cross a page boundary. 1466 */ 1467 static inline void clone_pgd_range(pgd_t *dst, pgd_t *src, int count) 1468 { 1469 memcpy(dst, src, count * sizeof(pgd_t)); 1470 #ifdef CONFIG_PAGE_TABLE_ISOLATION 1471 if (!static_cpu_has(X86_FEATURE_PTI)) 1472 return; 1473 /* Clone the user space pgd as well */ 1474 memcpy(kernel_to_user_pgdp(dst), kernel_to_user_pgdp(src), 1475 count * sizeof(pgd_t)); 1476 #endif 1477 } 1478 1479 #define PTE_SHIFT ilog2(PTRS_PER_PTE) 1480 static inline int page_level_shift(enum pg_level level) 1481 { 1482 return (PAGE_SHIFT - PTE_SHIFT) + level * PTE_SHIFT; 1483 } 1484 static inline unsigned long page_level_size(enum pg_level level) 1485 { 1486 return 1UL << page_level_shift(level); 1487 } 1488 static inline unsigned long page_level_mask(enum pg_level level) 1489 { 1490 return ~(page_level_size(level) - 1); 1491 } 1492 1493 /* 1494 * The x86 doesn't have any external MMU info: the kernel page 1495 * tables contain all the necessary information. 1496 */ 1497 static inline void update_mmu_cache(struct vm_area_struct *vma, 1498 unsigned long addr, pte_t *ptep) 1499 { 1500 } 1501 static inline void update_mmu_cache_range(struct vm_fault *vmf, 1502 struct vm_area_struct *vma, unsigned long addr, 1503 pte_t *ptep, unsigned int nr) 1504 { 1505 } 1506 static inline void update_mmu_cache_pmd(struct vm_area_struct *vma, 1507 unsigned long addr, pmd_t *pmd) 1508 { 1509 } 1510 static inline void update_mmu_cache_pud(struct vm_area_struct *vma, 1511 unsigned long addr, pud_t *pud) 1512 { 1513 } 1514 static inline pte_t pte_swp_mkexclusive(pte_t pte) 1515 { 1516 return pte_set_flags(pte, _PAGE_SWP_EXCLUSIVE); 1517 } 1518 1519 static inline int pte_swp_exclusive(pte_t pte) 1520 { 1521 return pte_flags(pte) & _PAGE_SWP_EXCLUSIVE; 1522 } 1523 1524 static inline pte_t pte_swp_clear_exclusive(pte_t pte) 1525 { 1526 return pte_clear_flags(pte, _PAGE_SWP_EXCLUSIVE); 1527 } 1528 1529 #ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY 1530 static inline pte_t pte_swp_mksoft_dirty(pte_t pte) 1531 { 1532 return pte_set_flags(pte, _PAGE_SWP_SOFT_DIRTY); 1533 } 1534 1535 static inline int pte_swp_soft_dirty(pte_t pte) 1536 { 1537 return pte_flags(pte) & _PAGE_SWP_SOFT_DIRTY; 1538 } 1539 1540 static inline pte_t pte_swp_clear_soft_dirty(pte_t pte) 1541 { 1542 return pte_clear_flags(pte, _PAGE_SWP_SOFT_DIRTY); 1543 } 1544 1545 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION 1546 static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd) 1547 { 1548 return pmd_set_flags(pmd, _PAGE_SWP_SOFT_DIRTY); 1549 } 1550 1551 static inline int pmd_swp_soft_dirty(pmd_t pmd) 1552 { 1553 return pmd_flags(pmd) & _PAGE_SWP_SOFT_DIRTY; 1554 } 1555 1556 static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd) 1557 { 1558 return pmd_clear_flags(pmd, _PAGE_SWP_SOFT_DIRTY); 1559 } 1560 #endif 1561 #endif 1562 1563 #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP 1564 static inline pte_t pte_swp_mkuffd_wp(pte_t pte) 1565 { 1566 return pte_set_flags(pte, _PAGE_SWP_UFFD_WP); 1567 } 1568 1569 static inline int pte_swp_uffd_wp(pte_t pte) 1570 { 1571 return pte_flags(pte) & _PAGE_SWP_UFFD_WP; 1572 } 1573 1574 static inline pte_t pte_swp_clear_uffd_wp(pte_t pte) 1575 { 1576 return pte_clear_flags(pte, _PAGE_SWP_UFFD_WP); 1577 } 1578 1579 static inline pmd_t pmd_swp_mkuffd_wp(pmd_t pmd) 1580 { 1581 return pmd_set_flags(pmd, _PAGE_SWP_UFFD_WP); 1582 } 1583 1584 static inline int pmd_swp_uffd_wp(pmd_t pmd) 1585 { 1586 return pmd_flags(pmd) & _PAGE_SWP_UFFD_WP; 1587 } 1588 1589 static inline pmd_t pmd_swp_clear_uffd_wp(pmd_t pmd) 1590 { 1591 return pmd_clear_flags(pmd, _PAGE_SWP_UFFD_WP); 1592 } 1593 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */ 1594 1595 static inline u16 pte_flags_pkey(unsigned long pte_flags) 1596 { 1597 #ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS 1598 /* ifdef to avoid doing 59-bit shift on 32-bit values */ 1599 return (pte_flags & _PAGE_PKEY_MASK) >> _PAGE_BIT_PKEY_BIT0; 1600 #else 1601 return 0; 1602 #endif 1603 } 1604 1605 static inline bool __pkru_allows_pkey(u16 pkey, bool write) 1606 { 1607 u32 pkru = read_pkru(); 1608 1609 if (!__pkru_allows_read(pkru, pkey)) 1610 return false; 1611 if (write && !__pkru_allows_write(pkru, pkey)) 1612 return false; 1613 1614 return true; 1615 } 1616 1617 /* 1618 * 'pteval' can come from a PTE, PMD or PUD. We only check 1619 * _PAGE_PRESENT, _PAGE_USER, and _PAGE_RW in here which are the 1620 * same value on all 3 types. 1621 */ 1622 static inline bool __pte_access_permitted(unsigned long pteval, bool write) 1623 { 1624 unsigned long need_pte_bits = _PAGE_PRESENT|_PAGE_USER; 1625 1626 /* 1627 * Write=0,Dirty=1 PTEs are shadow stack, which the kernel 1628 * shouldn't generally allow access to, but since they 1629 * are already Write=0, the below logic covers both cases. 1630 */ 1631 if (write) 1632 need_pte_bits |= _PAGE_RW; 1633 1634 if ((pteval & need_pte_bits) != need_pte_bits) 1635 return 0; 1636 1637 return __pkru_allows_pkey(pte_flags_pkey(pteval), write); 1638 } 1639 1640 #define pte_access_permitted pte_access_permitted 1641 static inline bool pte_access_permitted(pte_t pte, bool write) 1642 { 1643 return __pte_access_permitted(pte_val(pte), write); 1644 } 1645 1646 #define pmd_access_permitted pmd_access_permitted 1647 static inline bool pmd_access_permitted(pmd_t pmd, bool write) 1648 { 1649 return __pte_access_permitted(pmd_val(pmd), write); 1650 } 1651 1652 #define pud_access_permitted pud_access_permitted 1653 static inline bool pud_access_permitted(pud_t pud, bool write) 1654 { 1655 return __pte_access_permitted(pud_val(pud), write); 1656 } 1657 1658 #define __HAVE_ARCH_PFN_MODIFY_ALLOWED 1 1659 extern bool pfn_modify_allowed(unsigned long pfn, pgprot_t prot); 1660 1661 static inline bool arch_has_pfn_modify_check(void) 1662 { 1663 return boot_cpu_has_bug(X86_BUG_L1TF); 1664 } 1665 1666 #define arch_has_hw_pte_young arch_has_hw_pte_young 1667 static inline bool arch_has_hw_pte_young(void) 1668 { 1669 return true; 1670 } 1671 1672 #define arch_check_zapped_pte arch_check_zapped_pte 1673 void arch_check_zapped_pte(struct vm_area_struct *vma, pte_t pte); 1674 1675 #define arch_check_zapped_pmd arch_check_zapped_pmd 1676 void arch_check_zapped_pmd(struct vm_area_struct *vma, pmd_t pmd); 1677 1678 #ifdef CONFIG_XEN_PV 1679 #define arch_has_hw_nonleaf_pmd_young arch_has_hw_nonleaf_pmd_young 1680 static inline bool arch_has_hw_nonleaf_pmd_young(void) 1681 { 1682 return !cpu_feature_enabled(X86_FEATURE_XENPV); 1683 } 1684 #endif 1685 1686 #ifdef CONFIG_PAGE_TABLE_CHECK 1687 static inline bool pte_user_accessible_page(pte_t pte) 1688 { 1689 return (pte_val(pte) & _PAGE_PRESENT) && (pte_val(pte) & _PAGE_USER); 1690 } 1691 1692 static inline bool pmd_user_accessible_page(pmd_t pmd) 1693 { 1694 return pmd_leaf(pmd) && (pmd_val(pmd) & _PAGE_PRESENT) && (pmd_val(pmd) & _PAGE_USER); 1695 } 1696 1697 static inline bool pud_user_accessible_page(pud_t pud) 1698 { 1699 return pud_leaf(pud) && (pud_val(pud) & _PAGE_PRESENT) && (pud_val(pud) & _PAGE_USER); 1700 } 1701 #endif 1702 1703 #endif /* __ASSEMBLY__ */ 1704 1705 #endif /* _ASM_X86_PGTABLE_H */ 1706