1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * This kernel test validates architecture page table helpers and 4 * accessors and helps in verifying their continued compliance with 5 * expected generic MM semantics. 6 * 7 * Copyright (C) 2019 ARM Ltd. 8 * 9 * Author: Anshuman Khandual <anshuman.khandual@arm.com> 10 */ 11 #define pr_fmt(fmt) "debug_vm_pgtable: [%-25s]: " fmt, __func__ 12 13 #include <linux/gfp.h> 14 #include <linux/highmem.h> 15 #include <linux/hugetlb.h> 16 #include <linux/kernel.h> 17 #include <linux/kconfig.h> 18 #include <linux/mm.h> 19 #include <linux/mman.h> 20 #include <linux/mm_types.h> 21 #include <linux/module.h> 22 #include <linux/pfn_t.h> 23 #include <linux/printk.h> 24 #include <linux/pgtable.h> 25 #include <linux/random.h> 26 #include <linux/spinlock.h> 27 #include <linux/swap.h> 28 #include <linux/swapops.h> 29 #include <linux/start_kernel.h> 30 #include <linux/sched/mm.h> 31 #include <asm/pgalloc.h> 32 #include <asm/tlbflush.h> 33 34 /* 35 * Please refer Documentation/vm/arch_pgtable_helpers.rst for the semantics 36 * expectations that are being validated here. All future changes in here 37 * or the documentation need to be in sync. 38 */ 39 40 #define VMFLAGS (VM_READ|VM_WRITE|VM_EXEC) 41 42 /* 43 * On s390 platform, the lower 4 bits are used to identify given page table 44 * entry type. But these bits might affect the ability to clear entries with 45 * pxx_clear() because of how dynamic page table folding works on s390. So 46 * while loading up the entries do not change the lower 4 bits. It does not 47 * have affect any other platform. 48 */ 49 #define S390_MASK_BITS 4 50 #define RANDOM_ORVALUE GENMASK(BITS_PER_LONG - 1, S390_MASK_BITS) 51 #define RANDOM_NZVALUE GENMASK(7, 0) 52 53 static void __init pte_basic_tests(unsigned long pfn, pgprot_t prot) 54 { 55 pte_t pte = pfn_pte(pfn, prot); 56 57 pr_debug("Validating PTE basic\n"); 58 WARN_ON(!pte_same(pte, pte)); 59 WARN_ON(!pte_young(pte_mkyoung(pte_mkold(pte)))); 60 WARN_ON(!pte_dirty(pte_mkdirty(pte_mkclean(pte)))); 61 WARN_ON(!pte_write(pte_mkwrite(pte_wrprotect(pte)))); 62 WARN_ON(pte_young(pte_mkold(pte_mkyoung(pte)))); 63 WARN_ON(pte_dirty(pte_mkclean(pte_mkdirty(pte)))); 64 WARN_ON(pte_write(pte_wrprotect(pte_mkwrite(pte)))); 65 } 66 67 static void __init pte_advanced_tests(struct mm_struct *mm, 68 struct vm_area_struct *vma, pte_t *ptep, 69 unsigned long pfn, unsigned long vaddr, 70 pgprot_t prot) 71 { 72 pte_t pte = pfn_pte(pfn, prot); 73 74 pr_debug("Validating PTE advanced\n"); 75 pte = pfn_pte(pfn, prot); 76 set_pte_at(mm, vaddr, ptep, pte); 77 ptep_set_wrprotect(mm, vaddr, ptep); 78 pte = ptep_get(ptep); 79 WARN_ON(pte_write(pte)); 80 81 pte = pfn_pte(pfn, prot); 82 set_pte_at(mm, vaddr, ptep, pte); 83 ptep_get_and_clear(mm, vaddr, ptep); 84 pte = ptep_get(ptep); 85 WARN_ON(!pte_none(pte)); 86 87 pte = pfn_pte(pfn, prot); 88 pte = pte_wrprotect(pte); 89 pte = pte_mkclean(pte); 90 set_pte_at(mm, vaddr, ptep, pte); 91 pte = pte_mkwrite(pte); 92 pte = pte_mkdirty(pte); 93 ptep_set_access_flags(vma, vaddr, ptep, pte, 1); 94 pte = ptep_get(ptep); 95 WARN_ON(!(pte_write(pte) && pte_dirty(pte))); 96 97 pte = pfn_pte(pfn, prot); 98 set_pte_at(mm, vaddr, ptep, pte); 99 ptep_get_and_clear_full(mm, vaddr, ptep, 1); 100 pte = ptep_get(ptep); 101 WARN_ON(!pte_none(pte)); 102 103 pte = pte_mkyoung(pte); 104 set_pte_at(mm, vaddr, ptep, pte); 105 ptep_test_and_clear_young(vma, vaddr, ptep); 106 pte = ptep_get(ptep); 107 WARN_ON(pte_young(pte)); 108 } 109 110 static void __init pte_savedwrite_tests(unsigned long pfn, pgprot_t prot) 111 { 112 pte_t pte = pfn_pte(pfn, prot); 113 114 pr_debug("Validating PTE saved write\n"); 115 WARN_ON(!pte_savedwrite(pte_mk_savedwrite(pte_clear_savedwrite(pte)))); 116 WARN_ON(pte_savedwrite(pte_clear_savedwrite(pte_mk_savedwrite(pte)))); 117 } 118 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 119 static void __init pmd_basic_tests(unsigned long pfn, pgprot_t prot) 120 { 121 pmd_t pmd = pfn_pmd(pfn, prot); 122 123 if (!has_transparent_hugepage()) 124 return; 125 126 pr_debug("Validating PMD basic\n"); 127 WARN_ON(!pmd_same(pmd, pmd)); 128 WARN_ON(!pmd_young(pmd_mkyoung(pmd_mkold(pmd)))); 129 WARN_ON(!pmd_dirty(pmd_mkdirty(pmd_mkclean(pmd)))); 130 WARN_ON(!pmd_write(pmd_mkwrite(pmd_wrprotect(pmd)))); 131 WARN_ON(pmd_young(pmd_mkold(pmd_mkyoung(pmd)))); 132 WARN_ON(pmd_dirty(pmd_mkclean(pmd_mkdirty(pmd)))); 133 WARN_ON(pmd_write(pmd_wrprotect(pmd_mkwrite(pmd)))); 134 /* 135 * A huge page does not point to next level page table 136 * entry. Hence this must qualify as pmd_bad(). 137 */ 138 WARN_ON(!pmd_bad(pmd_mkhuge(pmd))); 139 } 140 141 static void __init pmd_advanced_tests(struct mm_struct *mm, 142 struct vm_area_struct *vma, pmd_t *pmdp, 143 unsigned long pfn, unsigned long vaddr, 144 pgprot_t prot) 145 { 146 pmd_t pmd = pfn_pmd(pfn, prot); 147 148 if (!has_transparent_hugepage()) 149 return; 150 151 pr_debug("Validating PMD advanced\n"); 152 /* Align the address wrt HPAGE_PMD_SIZE */ 153 vaddr = (vaddr & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE; 154 155 pmd = pfn_pmd(pfn, prot); 156 set_pmd_at(mm, vaddr, pmdp, pmd); 157 pmdp_set_wrprotect(mm, vaddr, pmdp); 158 pmd = READ_ONCE(*pmdp); 159 WARN_ON(pmd_write(pmd)); 160 161 pmd = pfn_pmd(pfn, prot); 162 set_pmd_at(mm, vaddr, pmdp, pmd); 163 pmdp_huge_get_and_clear(mm, vaddr, pmdp); 164 pmd = READ_ONCE(*pmdp); 165 WARN_ON(!pmd_none(pmd)); 166 167 pmd = pfn_pmd(pfn, prot); 168 pmd = pmd_wrprotect(pmd); 169 pmd = pmd_mkclean(pmd); 170 set_pmd_at(mm, vaddr, pmdp, pmd); 171 pmd = pmd_mkwrite(pmd); 172 pmd = pmd_mkdirty(pmd); 173 pmdp_set_access_flags(vma, vaddr, pmdp, pmd, 1); 174 pmd = READ_ONCE(*pmdp); 175 WARN_ON(!(pmd_write(pmd) && pmd_dirty(pmd))); 176 177 pmd = pmd_mkhuge(pfn_pmd(pfn, prot)); 178 set_pmd_at(mm, vaddr, pmdp, pmd); 179 pmdp_huge_get_and_clear_full(vma, vaddr, pmdp, 1); 180 pmd = READ_ONCE(*pmdp); 181 WARN_ON(!pmd_none(pmd)); 182 183 pmd = pmd_mkyoung(pmd); 184 set_pmd_at(mm, vaddr, pmdp, pmd); 185 pmdp_test_and_clear_young(vma, vaddr, pmdp); 186 pmd = READ_ONCE(*pmdp); 187 WARN_ON(pmd_young(pmd)); 188 } 189 190 static void __init pmd_leaf_tests(unsigned long pfn, pgprot_t prot) 191 { 192 pmd_t pmd = pfn_pmd(pfn, prot); 193 194 pr_debug("Validating PMD leaf\n"); 195 /* 196 * PMD based THP is a leaf entry. 197 */ 198 pmd = pmd_mkhuge(pmd); 199 WARN_ON(!pmd_leaf(pmd)); 200 } 201 202 static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot) 203 { 204 pmd_t pmd; 205 206 if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMAP)) 207 return; 208 209 pr_debug("Validating PMD huge\n"); 210 /* 211 * X86 defined pmd_set_huge() verifies that the given 212 * PMD is not a populated non-leaf entry. 213 */ 214 WRITE_ONCE(*pmdp, __pmd(0)); 215 WARN_ON(!pmd_set_huge(pmdp, __pfn_to_phys(pfn), prot)); 216 WARN_ON(!pmd_clear_huge(pmdp)); 217 pmd = READ_ONCE(*pmdp); 218 WARN_ON(!pmd_none(pmd)); 219 } 220 221 static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot) 222 { 223 pmd_t pmd = pfn_pmd(pfn, prot); 224 225 pr_debug("Validating PMD saved write\n"); 226 WARN_ON(!pmd_savedwrite(pmd_mk_savedwrite(pmd_clear_savedwrite(pmd)))); 227 WARN_ON(pmd_savedwrite(pmd_clear_savedwrite(pmd_mk_savedwrite(pmd)))); 228 } 229 230 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD 231 static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot) 232 { 233 pud_t pud = pfn_pud(pfn, prot); 234 235 if (!has_transparent_hugepage()) 236 return; 237 238 pr_debug("Validating PUD basic\n"); 239 WARN_ON(!pud_same(pud, pud)); 240 WARN_ON(!pud_young(pud_mkyoung(pud_mkold(pud)))); 241 WARN_ON(!pud_write(pud_mkwrite(pud_wrprotect(pud)))); 242 WARN_ON(pud_write(pud_wrprotect(pud_mkwrite(pud)))); 243 WARN_ON(pud_young(pud_mkold(pud_mkyoung(pud)))); 244 245 if (mm_pmd_folded(mm)) 246 return; 247 248 /* 249 * A huge page does not point to next level page table 250 * entry. Hence this must qualify as pud_bad(). 251 */ 252 WARN_ON(!pud_bad(pud_mkhuge(pud))); 253 } 254 255 static void __init pud_advanced_tests(struct mm_struct *mm, 256 struct vm_area_struct *vma, pud_t *pudp, 257 unsigned long pfn, unsigned long vaddr, 258 pgprot_t prot) 259 { 260 pud_t pud = pfn_pud(pfn, prot); 261 262 if (!has_transparent_hugepage()) 263 return; 264 265 pr_debug("Validating PUD advanced\n"); 266 /* Align the address wrt HPAGE_PUD_SIZE */ 267 vaddr = (vaddr & HPAGE_PUD_MASK) + HPAGE_PUD_SIZE; 268 269 set_pud_at(mm, vaddr, pudp, pud); 270 pudp_set_wrprotect(mm, vaddr, pudp); 271 pud = READ_ONCE(*pudp); 272 WARN_ON(pud_write(pud)); 273 274 #ifndef __PAGETABLE_PMD_FOLDED 275 pud = pfn_pud(pfn, prot); 276 set_pud_at(mm, vaddr, pudp, pud); 277 pudp_huge_get_and_clear(mm, vaddr, pudp); 278 pud = READ_ONCE(*pudp); 279 WARN_ON(!pud_none(pud)); 280 281 pud = pfn_pud(pfn, prot); 282 set_pud_at(mm, vaddr, pudp, pud); 283 pudp_huge_get_and_clear_full(mm, vaddr, pudp, 1); 284 pud = READ_ONCE(*pudp); 285 WARN_ON(!pud_none(pud)); 286 #endif /* __PAGETABLE_PMD_FOLDED */ 287 pud = pfn_pud(pfn, prot); 288 pud = pud_wrprotect(pud); 289 pud = pud_mkclean(pud); 290 set_pud_at(mm, vaddr, pudp, pud); 291 pud = pud_mkwrite(pud); 292 pud = pud_mkdirty(pud); 293 pudp_set_access_flags(vma, vaddr, pudp, pud, 1); 294 pud = READ_ONCE(*pudp); 295 WARN_ON(!(pud_write(pud) && pud_dirty(pud))); 296 297 pud = pud_mkyoung(pud); 298 set_pud_at(mm, vaddr, pudp, pud); 299 pudp_test_and_clear_young(vma, vaddr, pudp); 300 pud = READ_ONCE(*pudp); 301 WARN_ON(pud_young(pud)); 302 } 303 304 static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot) 305 { 306 pud_t pud = pfn_pud(pfn, prot); 307 308 pr_debug("Validating PUD leaf\n"); 309 /* 310 * PUD based THP is a leaf entry. 311 */ 312 pud = pud_mkhuge(pud); 313 WARN_ON(!pud_leaf(pud)); 314 } 315 316 static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot) 317 { 318 pud_t pud; 319 320 if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMAP)) 321 return; 322 323 pr_debug("Validating PUD huge\n"); 324 /* 325 * X86 defined pud_set_huge() verifies that the given 326 * PUD is not a populated non-leaf entry. 327 */ 328 WRITE_ONCE(*pudp, __pud(0)); 329 WARN_ON(!pud_set_huge(pudp, __pfn_to_phys(pfn), prot)); 330 WARN_ON(!pud_clear_huge(pudp)); 331 pud = READ_ONCE(*pudp); 332 WARN_ON(!pud_none(pud)); 333 } 334 #else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ 335 static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot) { } 336 static void __init pud_advanced_tests(struct mm_struct *mm, 337 struct vm_area_struct *vma, pud_t *pudp, 338 unsigned long pfn, unsigned long vaddr, 339 pgprot_t prot) 340 { 341 } 342 static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot) { } 343 static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot) 344 { 345 } 346 #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ 347 #else /* !CONFIG_TRANSPARENT_HUGEPAGE */ 348 static void __init pmd_basic_tests(unsigned long pfn, pgprot_t prot) { } 349 static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot) { } 350 static void __init pmd_advanced_tests(struct mm_struct *mm, 351 struct vm_area_struct *vma, pmd_t *pmdp, 352 unsigned long pfn, unsigned long vaddr, 353 pgprot_t prot) 354 { 355 } 356 static void __init pud_advanced_tests(struct mm_struct *mm, 357 struct vm_area_struct *vma, pud_t *pudp, 358 unsigned long pfn, unsigned long vaddr, 359 pgprot_t prot) 360 { 361 } 362 static void __init pmd_leaf_tests(unsigned long pfn, pgprot_t prot) { } 363 static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot) { } 364 static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot) 365 { 366 } 367 static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot) 368 { 369 } 370 static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot) { } 371 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 372 373 static void __init p4d_basic_tests(unsigned long pfn, pgprot_t prot) 374 { 375 p4d_t p4d; 376 377 pr_debug("Validating P4D basic\n"); 378 memset(&p4d, RANDOM_NZVALUE, sizeof(p4d_t)); 379 WARN_ON(!p4d_same(p4d, p4d)); 380 } 381 382 static void __init pgd_basic_tests(unsigned long pfn, pgprot_t prot) 383 { 384 pgd_t pgd; 385 386 pr_debug("Validating PGD basic\n"); 387 memset(&pgd, RANDOM_NZVALUE, sizeof(pgd_t)); 388 WARN_ON(!pgd_same(pgd, pgd)); 389 } 390 391 #ifndef __PAGETABLE_PUD_FOLDED 392 static void __init pud_clear_tests(struct mm_struct *mm, pud_t *pudp) 393 { 394 pud_t pud = READ_ONCE(*pudp); 395 396 if (mm_pmd_folded(mm)) 397 return; 398 399 pr_debug("Validating PUD clear\n"); 400 pud = __pud(pud_val(pud) | RANDOM_ORVALUE); 401 WRITE_ONCE(*pudp, pud); 402 pud_clear(pudp); 403 pud = READ_ONCE(*pudp); 404 WARN_ON(!pud_none(pud)); 405 } 406 407 static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp, 408 pmd_t *pmdp) 409 { 410 pud_t pud; 411 412 if (mm_pmd_folded(mm)) 413 return; 414 415 pr_debug("Validating PUD populate\n"); 416 /* 417 * This entry points to next level page table page. 418 * Hence this must not qualify as pud_bad(). 419 */ 420 pmd_clear(pmdp); 421 pud_clear(pudp); 422 pud_populate(mm, pudp, pmdp); 423 pud = READ_ONCE(*pudp); 424 WARN_ON(pud_bad(pud)); 425 } 426 #else /* !__PAGETABLE_PUD_FOLDED */ 427 static void __init pud_clear_tests(struct mm_struct *mm, pud_t *pudp) { } 428 static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp, 429 pmd_t *pmdp) 430 { 431 } 432 #endif /* PAGETABLE_PUD_FOLDED */ 433 434 #ifndef __PAGETABLE_P4D_FOLDED 435 static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp) 436 { 437 p4d_t p4d = READ_ONCE(*p4dp); 438 439 if (mm_pud_folded(mm)) 440 return; 441 442 pr_debug("Validating P4D clear\n"); 443 p4d = __p4d(p4d_val(p4d) | RANDOM_ORVALUE); 444 WRITE_ONCE(*p4dp, p4d); 445 p4d_clear(p4dp); 446 p4d = READ_ONCE(*p4dp); 447 WARN_ON(!p4d_none(p4d)); 448 } 449 450 static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp, 451 pud_t *pudp) 452 { 453 p4d_t p4d; 454 455 if (mm_pud_folded(mm)) 456 return; 457 458 pr_debug("Validating P4D populate\n"); 459 /* 460 * This entry points to next level page table page. 461 * Hence this must not qualify as p4d_bad(). 462 */ 463 pud_clear(pudp); 464 p4d_clear(p4dp); 465 p4d_populate(mm, p4dp, pudp); 466 p4d = READ_ONCE(*p4dp); 467 WARN_ON(p4d_bad(p4d)); 468 } 469 470 static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp) 471 { 472 pgd_t pgd = READ_ONCE(*pgdp); 473 474 if (mm_p4d_folded(mm)) 475 return; 476 477 pr_debug("Validating PGD clear\n"); 478 pgd = __pgd(pgd_val(pgd) | RANDOM_ORVALUE); 479 WRITE_ONCE(*pgdp, pgd); 480 pgd_clear(pgdp); 481 pgd = READ_ONCE(*pgdp); 482 WARN_ON(!pgd_none(pgd)); 483 } 484 485 static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp, 486 p4d_t *p4dp) 487 { 488 pgd_t pgd; 489 490 if (mm_p4d_folded(mm)) 491 return; 492 493 pr_debug("Validating PGD populate\n"); 494 /* 495 * This entry points to next level page table page. 496 * Hence this must not qualify as pgd_bad(). 497 */ 498 p4d_clear(p4dp); 499 pgd_clear(pgdp); 500 pgd_populate(mm, pgdp, p4dp); 501 pgd = READ_ONCE(*pgdp); 502 WARN_ON(pgd_bad(pgd)); 503 } 504 #else /* !__PAGETABLE_P4D_FOLDED */ 505 static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp) { } 506 static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp) { } 507 static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp, 508 pud_t *pudp) 509 { 510 } 511 static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp, 512 p4d_t *p4dp) 513 { 514 } 515 #endif /* PAGETABLE_P4D_FOLDED */ 516 517 static void __init pte_clear_tests(struct mm_struct *mm, pte_t *ptep, 518 unsigned long vaddr) 519 { 520 pte_t pte = ptep_get(ptep); 521 522 pr_debug("Validating PTE clear\n"); 523 pte = __pte(pte_val(pte) | RANDOM_ORVALUE); 524 set_pte_at(mm, vaddr, ptep, pte); 525 barrier(); 526 pte_clear(mm, vaddr, ptep); 527 pte = ptep_get(ptep); 528 WARN_ON(!pte_none(pte)); 529 } 530 531 static void __init pmd_clear_tests(struct mm_struct *mm, pmd_t *pmdp) 532 { 533 pmd_t pmd = READ_ONCE(*pmdp); 534 535 pr_debug("Validating PMD clear\n"); 536 pmd = __pmd(pmd_val(pmd) | RANDOM_ORVALUE); 537 WRITE_ONCE(*pmdp, pmd); 538 pmd_clear(pmdp); 539 pmd = READ_ONCE(*pmdp); 540 WARN_ON(!pmd_none(pmd)); 541 } 542 543 static void __init pmd_populate_tests(struct mm_struct *mm, pmd_t *pmdp, 544 pgtable_t pgtable) 545 { 546 pmd_t pmd; 547 548 pr_debug("Validating PMD populate\n"); 549 /* 550 * This entry points to next level page table page. 551 * Hence this must not qualify as pmd_bad(). 552 */ 553 pmd_clear(pmdp); 554 pmd_populate(mm, pmdp, pgtable); 555 pmd = READ_ONCE(*pmdp); 556 WARN_ON(pmd_bad(pmd)); 557 } 558 559 static void __init pte_special_tests(unsigned long pfn, pgprot_t prot) 560 { 561 pte_t pte = pfn_pte(pfn, prot); 562 563 if (!IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL)) 564 return; 565 566 pr_debug("Validating PTE special\n"); 567 WARN_ON(!pte_special(pte_mkspecial(pte))); 568 } 569 570 static void __init pte_protnone_tests(unsigned long pfn, pgprot_t prot) 571 { 572 pte_t pte = pfn_pte(pfn, prot); 573 574 if (!IS_ENABLED(CONFIG_NUMA_BALANCING)) 575 return; 576 577 pr_debug("Validating PTE protnone\n"); 578 WARN_ON(!pte_protnone(pte)); 579 WARN_ON(!pte_present(pte)); 580 } 581 582 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 583 static void __init pmd_protnone_tests(unsigned long pfn, pgprot_t prot) 584 { 585 pmd_t pmd = pmd_mkhuge(pfn_pmd(pfn, prot)); 586 587 if (!IS_ENABLED(CONFIG_NUMA_BALANCING)) 588 return; 589 590 pr_debug("Validating PMD protnone\n"); 591 WARN_ON(!pmd_protnone(pmd)); 592 WARN_ON(!pmd_present(pmd)); 593 } 594 #else /* !CONFIG_TRANSPARENT_HUGEPAGE */ 595 static void __init pmd_protnone_tests(unsigned long pfn, pgprot_t prot) { } 596 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 597 598 #ifdef CONFIG_ARCH_HAS_PTE_DEVMAP 599 static void __init pte_devmap_tests(unsigned long pfn, pgprot_t prot) 600 { 601 pte_t pte = pfn_pte(pfn, prot); 602 603 pr_debug("Validating PTE devmap\n"); 604 WARN_ON(!pte_devmap(pte_mkdevmap(pte))); 605 } 606 607 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 608 static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot) 609 { 610 pmd_t pmd = pfn_pmd(pfn, prot); 611 612 pr_debug("Validating PMD devmap\n"); 613 WARN_ON(!pmd_devmap(pmd_mkdevmap(pmd))); 614 } 615 616 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD 617 static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) 618 { 619 pud_t pud = pfn_pud(pfn, prot); 620 621 pr_debug("Validating PUD devmap\n"); 622 WARN_ON(!pud_devmap(pud_mkdevmap(pud))); 623 } 624 #else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ 625 static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) { } 626 #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ 627 #else /* CONFIG_TRANSPARENT_HUGEPAGE */ 628 static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot) { } 629 static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) { } 630 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 631 #else 632 static void __init pte_devmap_tests(unsigned long pfn, pgprot_t prot) { } 633 static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot) { } 634 static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) { } 635 #endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */ 636 637 static void __init pte_soft_dirty_tests(unsigned long pfn, pgprot_t prot) 638 { 639 pte_t pte = pfn_pte(pfn, prot); 640 641 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY)) 642 return; 643 644 pr_debug("Validating PTE soft dirty\n"); 645 WARN_ON(!pte_soft_dirty(pte_mksoft_dirty(pte))); 646 WARN_ON(pte_soft_dirty(pte_clear_soft_dirty(pte))); 647 } 648 649 static void __init pte_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot) 650 { 651 pte_t pte = pfn_pte(pfn, prot); 652 653 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY)) 654 return; 655 656 pr_debug("Validating PTE swap soft dirty\n"); 657 WARN_ON(!pte_swp_soft_dirty(pte_swp_mksoft_dirty(pte))); 658 WARN_ON(pte_swp_soft_dirty(pte_swp_clear_soft_dirty(pte))); 659 } 660 661 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 662 static void __init pmd_soft_dirty_tests(unsigned long pfn, pgprot_t prot) 663 { 664 pmd_t pmd = pfn_pmd(pfn, prot); 665 666 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY)) 667 return; 668 669 pr_debug("Validating PMD soft dirty\n"); 670 WARN_ON(!pmd_soft_dirty(pmd_mksoft_dirty(pmd))); 671 WARN_ON(pmd_soft_dirty(pmd_clear_soft_dirty(pmd))); 672 } 673 674 static void __init pmd_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot) 675 { 676 pmd_t pmd = pfn_pmd(pfn, prot); 677 678 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY) || 679 !IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION)) 680 return; 681 682 pr_debug("Validating PMD swap soft dirty\n"); 683 WARN_ON(!pmd_swp_soft_dirty(pmd_swp_mksoft_dirty(pmd))); 684 WARN_ON(pmd_swp_soft_dirty(pmd_swp_clear_soft_dirty(pmd))); 685 } 686 #else /* !CONFIG_ARCH_HAS_PTE_DEVMAP */ 687 static void __init pmd_soft_dirty_tests(unsigned long pfn, pgprot_t prot) { } 688 static void __init pmd_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot) 689 { 690 } 691 #endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */ 692 693 static void __init pte_swap_tests(unsigned long pfn, pgprot_t prot) 694 { 695 swp_entry_t swp; 696 pte_t pte; 697 698 pr_debug("Validating PTE swap\n"); 699 pte = pfn_pte(pfn, prot); 700 swp = __pte_to_swp_entry(pte); 701 pte = __swp_entry_to_pte(swp); 702 WARN_ON(pfn != pte_pfn(pte)); 703 } 704 705 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION 706 static void __init pmd_swap_tests(unsigned long pfn, pgprot_t prot) 707 { 708 swp_entry_t swp; 709 pmd_t pmd; 710 711 pr_debug("Validating PMD swap\n"); 712 pmd = pfn_pmd(pfn, prot); 713 swp = __pmd_to_swp_entry(pmd); 714 pmd = __swp_entry_to_pmd(swp); 715 WARN_ON(pfn != pmd_pfn(pmd)); 716 } 717 #else /* !CONFIG_ARCH_ENABLE_THP_MIGRATION */ 718 static void __init pmd_swap_tests(unsigned long pfn, pgprot_t prot) { } 719 #endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */ 720 721 static void __init swap_migration_tests(void) 722 { 723 struct page *page; 724 swp_entry_t swp; 725 726 if (!IS_ENABLED(CONFIG_MIGRATION)) 727 return; 728 729 pr_debug("Validating swap migration\n"); 730 /* 731 * swap_migration_tests() requires a dedicated page as it needs to 732 * be locked before creating a migration entry from it. Locking the 733 * page that actually maps kernel text ('start_kernel') can be real 734 * problematic. Lets allocate a dedicated page explicitly for this 735 * purpose that will be freed subsequently. 736 */ 737 page = alloc_page(GFP_KERNEL); 738 if (!page) { 739 pr_err("page allocation failed\n"); 740 return; 741 } 742 743 /* 744 * make_migration_entry() expects given page to be 745 * locked, otherwise it stumbles upon a BUG_ON(). 746 */ 747 __SetPageLocked(page); 748 swp = make_migration_entry(page, 1); 749 WARN_ON(!is_migration_entry(swp)); 750 WARN_ON(!is_write_migration_entry(swp)); 751 752 make_migration_entry_read(&swp); 753 WARN_ON(!is_migration_entry(swp)); 754 WARN_ON(is_write_migration_entry(swp)); 755 756 swp = make_migration_entry(page, 0); 757 WARN_ON(!is_migration_entry(swp)); 758 WARN_ON(is_write_migration_entry(swp)); 759 __ClearPageLocked(page); 760 __free_page(page); 761 } 762 763 #ifdef CONFIG_HUGETLB_PAGE 764 static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot) 765 { 766 struct page *page; 767 pte_t pte; 768 769 pr_debug("Validating HugeTLB basic\n"); 770 /* 771 * Accessing the page associated with the pfn is safe here, 772 * as it was previously derived from a real kernel symbol. 773 */ 774 page = pfn_to_page(pfn); 775 pte = mk_huge_pte(page, prot); 776 777 WARN_ON(!huge_pte_dirty(huge_pte_mkdirty(pte))); 778 WARN_ON(!huge_pte_write(huge_pte_mkwrite(huge_pte_wrprotect(pte)))); 779 WARN_ON(huge_pte_write(huge_pte_wrprotect(huge_pte_mkwrite(pte)))); 780 781 #ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB 782 pte = pfn_pte(pfn, prot); 783 784 WARN_ON(!pte_huge(pte_mkhuge(pte))); 785 #endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */ 786 } 787 788 static void __init hugetlb_advanced_tests(struct mm_struct *mm, 789 struct vm_area_struct *vma, 790 pte_t *ptep, unsigned long pfn, 791 unsigned long vaddr, pgprot_t prot) 792 { 793 struct page *page = pfn_to_page(pfn); 794 pte_t pte = ptep_get(ptep); 795 unsigned long paddr = __pfn_to_phys(pfn) & PMD_MASK; 796 797 pr_debug("Validating HugeTLB advanced\n"); 798 pte = pte_mkhuge(mk_pte(pfn_to_page(PHYS_PFN(paddr)), prot)); 799 set_huge_pte_at(mm, vaddr, ptep, pte); 800 barrier(); 801 WARN_ON(!pte_same(pte, huge_ptep_get(ptep))); 802 huge_pte_clear(mm, vaddr, ptep, PMD_SIZE); 803 pte = huge_ptep_get(ptep); 804 WARN_ON(!huge_pte_none(pte)); 805 806 pte = mk_huge_pte(page, prot); 807 set_huge_pte_at(mm, vaddr, ptep, pte); 808 barrier(); 809 huge_ptep_set_wrprotect(mm, vaddr, ptep); 810 pte = huge_ptep_get(ptep); 811 WARN_ON(huge_pte_write(pte)); 812 813 pte = mk_huge_pte(page, prot); 814 set_huge_pte_at(mm, vaddr, ptep, pte); 815 barrier(); 816 huge_ptep_get_and_clear(mm, vaddr, ptep); 817 pte = huge_ptep_get(ptep); 818 WARN_ON(!huge_pte_none(pte)); 819 820 pte = mk_huge_pte(page, prot); 821 pte = huge_pte_wrprotect(pte); 822 set_huge_pte_at(mm, vaddr, ptep, pte); 823 barrier(); 824 pte = huge_pte_mkwrite(pte); 825 pte = huge_pte_mkdirty(pte); 826 huge_ptep_set_access_flags(vma, vaddr, ptep, pte, 1); 827 pte = huge_ptep_get(ptep); 828 WARN_ON(!(huge_pte_write(pte) && huge_pte_dirty(pte))); 829 } 830 #else /* !CONFIG_HUGETLB_PAGE */ 831 static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot) { } 832 static void __init hugetlb_advanced_tests(struct mm_struct *mm, 833 struct vm_area_struct *vma, 834 pte_t *ptep, unsigned long pfn, 835 unsigned long vaddr, pgprot_t prot) 836 { 837 } 838 #endif /* CONFIG_HUGETLB_PAGE */ 839 840 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 841 static void __init pmd_thp_tests(unsigned long pfn, pgprot_t prot) 842 { 843 pmd_t pmd; 844 845 if (!has_transparent_hugepage()) 846 return; 847 848 pr_debug("Validating PMD based THP\n"); 849 /* 850 * pmd_trans_huge() and pmd_present() must return positive after 851 * MMU invalidation with pmd_mkinvalid(). This behavior is an 852 * optimization for transparent huge page. pmd_trans_huge() must 853 * be true if pmd_page() returns a valid THP to avoid taking the 854 * pmd_lock when others walk over non transhuge pmds (i.e. there 855 * are no THP allocated). Especially when splitting a THP and 856 * removing the present bit from the pmd, pmd_trans_huge() still 857 * needs to return true. pmd_present() should be true whenever 858 * pmd_trans_huge() returns true. 859 */ 860 pmd = pfn_pmd(pfn, prot); 861 WARN_ON(!pmd_trans_huge(pmd_mkhuge(pmd))); 862 863 #ifndef __HAVE_ARCH_PMDP_INVALIDATE 864 WARN_ON(!pmd_trans_huge(pmd_mkinvalid(pmd_mkhuge(pmd)))); 865 WARN_ON(!pmd_present(pmd_mkinvalid(pmd_mkhuge(pmd)))); 866 #endif /* __HAVE_ARCH_PMDP_INVALIDATE */ 867 } 868 869 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD 870 static void __init pud_thp_tests(unsigned long pfn, pgprot_t prot) 871 { 872 pud_t pud; 873 874 if (!has_transparent_hugepage()) 875 return; 876 877 pr_debug("Validating PUD based THP\n"); 878 pud = pfn_pud(pfn, prot); 879 WARN_ON(!pud_trans_huge(pud_mkhuge(pud))); 880 881 /* 882 * pud_mkinvalid() has been dropped for now. Enable back 883 * these tests when it comes back with a modified pud_present(). 884 * 885 * WARN_ON(!pud_trans_huge(pud_mkinvalid(pud_mkhuge(pud)))); 886 * WARN_ON(!pud_present(pud_mkinvalid(pud_mkhuge(pud)))); 887 */ 888 } 889 #else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ 890 static void __init pud_thp_tests(unsigned long pfn, pgprot_t prot) { } 891 #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ 892 #else /* !CONFIG_TRANSPARENT_HUGEPAGE */ 893 static void __init pmd_thp_tests(unsigned long pfn, pgprot_t prot) { } 894 static void __init pud_thp_tests(unsigned long pfn, pgprot_t prot) { } 895 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 896 897 static unsigned long __init get_random_vaddr(void) 898 { 899 unsigned long random_vaddr, random_pages, total_user_pages; 900 901 total_user_pages = (TASK_SIZE - FIRST_USER_ADDRESS) / PAGE_SIZE; 902 903 random_pages = get_random_long() % total_user_pages; 904 random_vaddr = FIRST_USER_ADDRESS + random_pages * PAGE_SIZE; 905 906 return random_vaddr; 907 } 908 909 static int __init debug_vm_pgtable(void) 910 { 911 struct vm_area_struct *vma; 912 struct mm_struct *mm; 913 pgd_t *pgdp; 914 p4d_t *p4dp, *saved_p4dp; 915 pud_t *pudp, *saved_pudp; 916 pmd_t *pmdp, *saved_pmdp, pmd; 917 pte_t *ptep; 918 pgtable_t saved_ptep; 919 pgprot_t prot, protnone; 920 phys_addr_t paddr; 921 unsigned long vaddr, pte_aligned, pmd_aligned; 922 unsigned long pud_aligned, p4d_aligned, pgd_aligned; 923 spinlock_t *ptl = NULL; 924 925 pr_info("Validating architecture page table helpers\n"); 926 prot = vm_get_page_prot(VMFLAGS); 927 vaddr = get_random_vaddr(); 928 mm = mm_alloc(); 929 if (!mm) { 930 pr_err("mm_struct allocation failed\n"); 931 return 1; 932 } 933 934 /* 935 * __P000 (or even __S000) will help create page table entries with 936 * PROT_NONE permission as required for pxx_protnone_tests(). 937 */ 938 protnone = __P000; 939 940 vma = vm_area_alloc(mm); 941 if (!vma) { 942 pr_err("vma allocation failed\n"); 943 return 1; 944 } 945 946 /* 947 * PFN for mapping at PTE level is determined from a standard kernel 948 * text symbol. But pfns for higher page table levels are derived by 949 * masking lower bits of this real pfn. These derived pfns might not 950 * exist on the platform but that does not really matter as pfn_pxx() 951 * helpers will still create appropriate entries for the test. This 952 * helps avoid large memory block allocations to be used for mapping 953 * at higher page table levels. 954 */ 955 paddr = __pa_symbol(&start_kernel); 956 957 pte_aligned = (paddr & PAGE_MASK) >> PAGE_SHIFT; 958 pmd_aligned = (paddr & PMD_MASK) >> PAGE_SHIFT; 959 pud_aligned = (paddr & PUD_MASK) >> PAGE_SHIFT; 960 p4d_aligned = (paddr & P4D_MASK) >> PAGE_SHIFT; 961 pgd_aligned = (paddr & PGDIR_MASK) >> PAGE_SHIFT; 962 WARN_ON(!pfn_valid(pte_aligned)); 963 964 pgdp = pgd_offset(mm, vaddr); 965 p4dp = p4d_alloc(mm, pgdp, vaddr); 966 pudp = pud_alloc(mm, p4dp, vaddr); 967 pmdp = pmd_alloc(mm, pudp, vaddr); 968 ptep = pte_alloc_map_lock(mm, pmdp, vaddr, &ptl); 969 970 /* 971 * Save all the page table page addresses as the page table 972 * entries will be used for testing with random or garbage 973 * values. These saved addresses will be used for freeing 974 * page table pages. 975 */ 976 pmd = READ_ONCE(*pmdp); 977 saved_p4dp = p4d_offset(pgdp, 0UL); 978 saved_pudp = pud_offset(p4dp, 0UL); 979 saved_pmdp = pmd_offset(pudp, 0UL); 980 saved_ptep = pmd_pgtable(pmd); 981 982 pte_basic_tests(pte_aligned, prot); 983 pmd_basic_tests(pmd_aligned, prot); 984 pud_basic_tests(pud_aligned, prot); 985 p4d_basic_tests(p4d_aligned, prot); 986 pgd_basic_tests(pgd_aligned, prot); 987 988 pte_clear_tests(mm, ptep, vaddr); 989 pmd_clear_tests(mm, pmdp); 990 pud_clear_tests(mm, pudp); 991 p4d_clear_tests(mm, p4dp); 992 pgd_clear_tests(mm, pgdp); 993 994 pte_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot); 995 pmd_advanced_tests(mm, vma, pmdp, pmd_aligned, vaddr, prot); 996 pud_advanced_tests(mm, vma, pudp, pud_aligned, vaddr, prot); 997 hugetlb_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot); 998 999 pmd_leaf_tests(pmd_aligned, prot); 1000 pud_leaf_tests(pud_aligned, prot); 1001 1002 pmd_huge_tests(pmdp, pmd_aligned, prot); 1003 pud_huge_tests(pudp, pud_aligned, prot); 1004 1005 pte_savedwrite_tests(pte_aligned, prot); 1006 pmd_savedwrite_tests(pmd_aligned, prot); 1007 1008 pte_unmap_unlock(ptep, ptl); 1009 1010 pmd_populate_tests(mm, pmdp, saved_ptep); 1011 pud_populate_tests(mm, pudp, saved_pmdp); 1012 p4d_populate_tests(mm, p4dp, saved_pudp); 1013 pgd_populate_tests(mm, pgdp, saved_p4dp); 1014 1015 pte_special_tests(pte_aligned, prot); 1016 pte_protnone_tests(pte_aligned, protnone); 1017 pmd_protnone_tests(pmd_aligned, protnone); 1018 1019 pte_devmap_tests(pte_aligned, prot); 1020 pmd_devmap_tests(pmd_aligned, prot); 1021 pud_devmap_tests(pud_aligned, prot); 1022 1023 pte_soft_dirty_tests(pte_aligned, prot); 1024 pmd_soft_dirty_tests(pmd_aligned, prot); 1025 pte_swap_soft_dirty_tests(pte_aligned, prot); 1026 pmd_swap_soft_dirty_tests(pmd_aligned, prot); 1027 1028 pte_swap_tests(pte_aligned, prot); 1029 pmd_swap_tests(pmd_aligned, prot); 1030 1031 swap_migration_tests(); 1032 hugetlb_basic_tests(pte_aligned, prot); 1033 1034 pmd_thp_tests(pmd_aligned, prot); 1035 pud_thp_tests(pud_aligned, prot); 1036 1037 p4d_free(mm, saved_p4dp); 1038 pud_free(mm, saved_pudp); 1039 pmd_free(mm, saved_pmdp); 1040 pte_free(mm, saved_ptep); 1041 1042 vm_area_free(vma); 1043 mm_dec_nr_puds(mm); 1044 mm_dec_nr_pmds(mm); 1045 mm_dec_nr_ptes(mm); 1046 mmdrop(mm); 1047 return 0; 1048 } 1049 late_initcall(debug_vm_pgtable); 1050