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debug_vm_pgtable.c
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linux-6.19.14/mm/debug_vm_pgtable.c
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/memblock.h> 19#include <linux/mm.h> 20#include <linux/mman.h> 21#include <linux/mm_types.h> 22#include <linux/module.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/leafops.h> 29#include <linux/start_kernel.h> 30#include <linux/sched/mm.h> 31#include <linux/io.h> 32#include <linux/vmalloc.h> 33#include <linux/pgalloc.h> 34 35#include <asm/cacheflush.h> 36#include <asm/tlbflush.h> 37 38/* 39 * Please refer Documentation/mm/arch_pgtable_helpers.rst for the semantics 40 * expectations that are being validated here. All future changes in here 41 * or the documentation need to be in sync. 42 */ 43#define RANDOM_NZVALUE GENMASK(7, 0) 44 45struct pgtable_debug_args { 46 struct mm_struct *mm; 47 struct vm_area_struct *vma; 48 49 pgd_t *pgdp; 50 p4d_t *p4dp; 51 pud_t *pudp; 52 pmd_t *pmdp; 53 pte_t *ptep; 54 55 p4d_t *start_p4dp; 56 pud_t *start_pudp; 57 pmd_t *start_pmdp; 58 pgtable_t start_ptep; 59 60 unsigned long vaddr; 61 pgprot_t page_prot; 62 pgprot_t page_prot_none; 63 64 bool is_contiguous_page; 65 unsigned long pud_pfn; 66 unsigned long pmd_pfn; 67 unsigned long pte_pfn; 68 69 unsigned long fixed_alignment; 70 unsigned long fixed_pgd_pfn; 71 unsigned long fixed_p4d_pfn; 72 unsigned long fixed_pud_pfn; 73 unsigned long fixed_pmd_pfn; 74 unsigned long fixed_pte_pfn; 75 76 swp_entry_t swp_entry; 77 swp_entry_t leaf_entry; 78}; 79 80static void __init pte_basic_tests(struct pgtable_debug_args *args, int idx) 81{ 82 pgprot_t prot = vm_get_page_prot(idx); 83 pte_t pte = pfn_pte(args->fixed_pte_pfn, prot); 84 unsigned long val = idx, *ptr = &val; 85 86 pr_debug("Validating PTE basic (%pGv)\n", ptr); 87 88 /* 89 * This test needs to be executed after the given page table entry 90 * is created with pfn_pte() to make sure that vm_get_page_prot(idx) 91 * does not have the dirty bit enabled from the beginning. This is 92 * important for platforms like arm64 where (!PTE_RDONLY) indicate 93 * dirty bit being set. 94 */ 95 WARN_ON(pte_dirty(pte_wrprotect(pte))); 96 97 WARN_ON(!pte_same(pte, pte)); 98 WARN_ON(!pte_young(pte_mkyoung(pte_mkold(pte)))); 99 WARN_ON(!pte_dirty(pte_mkdirty(pte_mkclean(pte)))); 100 WARN_ON(!pte_write(pte_mkwrite(pte_wrprotect(pte), args->vma))); 101 WARN_ON(pte_young(pte_mkold(pte_mkyoung(pte)))); 102 WARN_ON(pte_dirty(pte_mkclean(pte_mkdirty(pte)))); 103 WARN_ON(pte_write(pte_wrprotect(pte_mkwrite(pte, args->vma)))); 104 WARN_ON(pte_dirty(pte_wrprotect(pte_mkclean(pte)))); 105 WARN_ON(!pte_dirty(pte_wrprotect(pte_mkdirty(pte)))); 106 107 WARN_ON(!pte_dirty(pte_mkwrite_novma(pte_mkdirty(pte)))); 108 WARN_ON(pte_dirty(pte_mkwrite_novma(pte_mkclean(pte)))); 109 WARN_ON(!pte_write(pte_mkdirty(pte_mkwrite_novma(pte)))); 110 WARN_ON(!pte_write(pte_mkwrite_novma(pte_wrprotect(pte)))); 111 WARN_ON(pte_write(pte_wrprotect(pte_mkwrite_novma(pte)))); 112} 113 114static void __init pte_advanced_tests(struct pgtable_debug_args *args) 115{ 116 struct page *page; 117 pte_t pte; 118 119 /* 120 * Architectures optimize set_pte_at by avoiding TLB flush. 121 * This requires set_pte_at to be not used to update an 122 * existing pte entry. Clear pte before we do set_pte_at 123 * 124 * flush_dcache_page() is called after set_pte_at() to clear 125 * PG_arch_1 for the page on ARM64. The page flag isn't cleared 126 * when it's released and page allocation check will fail when 127 * the page is allocated again. For architectures other than ARM64, 128 * the unexpected overhead of cache flushing is acceptable. 129 */ 130 page = (args->pte_pfn != ULONG_MAX) ? pfn_to_page(args->pte_pfn) : NULL; 131 if (!page) 132 return; 133 134 pr_debug("Validating PTE advanced\n"); 135 if (WARN_ON(!args->ptep)) 136 return; 137 138 pte = pfn_pte(args->pte_pfn, args->page_prot); 139 set_pte_at(args->mm, args->vaddr, args->ptep, pte); 140 flush_dcache_page(page); 141 ptep_set_wrprotect(args->mm, args->vaddr, args->ptep); 142 pte = ptep_get(args->ptep); 143 WARN_ON(pte_write(pte)); 144 ptep_get_and_clear(args->mm, args->vaddr, args->ptep); 145 pte = ptep_get(args->ptep); 146 WARN_ON(!pte_none(pte)); 147 148 pte = pfn_pte(args->pte_pfn, args->page_prot); 149 pte = pte_wrprotect(pte); 150 pte = pte_mkclean(pte); 151 set_pte_at(args->mm, args->vaddr, args->ptep, pte); 152 flush_dcache_page(page); 153 pte = pte_mkwrite(pte, args->vma); 154 pte = pte_mkdirty(pte); 155 ptep_set_access_flags(args->vma, args->vaddr, args->ptep, pte, 1); 156 pte = ptep_get(args->ptep); 157 WARN_ON(!(pte_write(pte) && pte_dirty(pte))); 158 ptep_get_and_clear_full(args->mm, args->vaddr, args->ptep, 1); 159 pte = ptep_get(args->ptep); 160 WARN_ON(!pte_none(pte)); 161 162 pte = pfn_pte(args->pte_pfn, args->page_prot); 163 pte = pte_mkyoung(pte); 164 set_pte_at(args->mm, args->vaddr, args->ptep, pte); 165 flush_dcache_page(page); 166 ptep_test_and_clear_young(args->vma, args->vaddr, args->ptep); 167 pte = ptep_get(args->ptep); 168 WARN_ON(pte_young(pte)); 169 170 ptep_get_and_clear_full(args->mm, args->vaddr, args->ptep, 1); 171} 172 173#ifdef CONFIG_TRANSPARENT_HUGEPAGE 174static void __init pmd_basic_tests(struct pgtable_debug_args *args, int idx) 175{ 176 pgprot_t prot = vm_get_page_prot(idx); 177 unsigned long val = idx, *ptr = &val; 178 pmd_t pmd; 179 180 if (!has_transparent_hugepage()) 181 return; 182 183 pr_debug("Validating PMD basic (%pGv)\n", ptr); 184 pmd = pfn_pmd(args->fixed_pmd_pfn, prot); 185 186 /* 187 * This test needs to be executed after the given page table entry 188 * is created with pfn_pmd() to make sure that vm_get_page_prot(idx) 189 * does not have the dirty bit enabled from the beginning. This is 190 * important for platforms like arm64 where (!PTE_RDONLY) indicate 191 * dirty bit being set. 192 */ 193 WARN_ON(pmd_dirty(pmd_wrprotect(pmd))); 194 195 196 WARN_ON(!pmd_same(pmd, pmd)); 197 WARN_ON(!pmd_young(pmd_mkyoung(pmd_mkold(pmd)))); 198 WARN_ON(!pmd_dirty(pmd_mkdirty(pmd_mkclean(pmd)))); 199 WARN_ON(!pmd_write(pmd_mkwrite(pmd_wrprotect(pmd), args->vma))); 200 WARN_ON(pmd_young(pmd_mkold(pmd_mkyoung(pmd)))); 201 WARN_ON(pmd_dirty(pmd_mkclean(pmd_mkdirty(pmd)))); 202 WARN_ON(pmd_write(pmd_wrprotect(pmd_mkwrite(pmd, args->vma)))); 203 WARN_ON(pmd_dirty(pmd_wrprotect(pmd_mkclean(pmd)))); 204 WARN_ON(!pmd_dirty(pmd_wrprotect(pmd_mkdirty(pmd)))); 205 206 WARN_ON(!pmd_dirty(pmd_mkwrite_novma(pmd_mkdirty(pmd)))); 207 WARN_ON(pmd_dirty(pmd_mkwrite_novma(pmd_mkclean(pmd)))); 208 WARN_ON(!pmd_write(pmd_mkdirty(pmd_mkwrite_novma(pmd)))); 209 WARN_ON(!pmd_write(pmd_mkwrite_novma(pmd_wrprotect(pmd)))); 210 WARN_ON(pmd_write(pmd_wrprotect(pmd_mkwrite_novma(pmd)))); 211 212 /* 213 * A huge page does not point to next level page table 214 * entry. Hence this must qualify as pmd_bad(). 215 */ 216 WARN_ON(!pmd_bad(pmd_mkhuge(pmd))); 217} 218 219static void __init pmd_advanced_tests(struct pgtable_debug_args *args) 220{ 221 struct page *page; 222 pmd_t pmd; 223 unsigned long vaddr = args->vaddr; 224 225 if (!has_transparent_hugepage()) 226 return; 227 228 page = (args->pmd_pfn != ULONG_MAX) ? pfn_to_page(args->pmd_pfn) : NULL; 229 if (!page) 230 return; 231 232 /* 233 * flush_dcache_page() is called after set_pmd_at() to clear 234 * PG_arch_1 for the page on ARM64. The page flag isn't cleared 235 * when it's released and page allocation check will fail when 236 * the page is allocated again. For architectures other than ARM64, 237 * the unexpected overhead of cache flushing is acceptable. 238 */ 239 pr_debug("Validating PMD advanced\n"); 240 /* Align the address wrt HPAGE_PMD_SIZE */ 241 vaddr &= HPAGE_PMD_MASK; 242 243 pgtable_trans_huge_deposit(args->mm, args->pmdp, args->start_ptep); 244 245 pmd = pfn_pmd(args->pmd_pfn, args->page_prot); 246 set_pmd_at(args->mm, vaddr, args->pmdp, pmd); 247 flush_dcache_page(page); 248 pmdp_set_wrprotect(args->mm, vaddr, args->pmdp); 249 pmd = pmdp_get(args->pmdp); 250 WARN_ON(pmd_write(pmd)); 251 pmdp_huge_get_and_clear(args->mm, vaddr, args->pmdp); 252 pmd = pmdp_get(args->pmdp); 253 WARN_ON(!pmd_none(pmd)); 254 255 pmd = pfn_pmd(args->pmd_pfn, args->page_prot); 256 pmd = pmd_wrprotect(pmd); 257 pmd = pmd_mkclean(pmd); 258 set_pmd_at(args->mm, vaddr, args->pmdp, pmd); 259 flush_dcache_page(page); 260 pmd = pmd_mkwrite(pmd, args->vma); 261 pmd = pmd_mkdirty(pmd); 262 pmdp_set_access_flags(args->vma, vaddr, args->pmdp, pmd, 1); 263 pmd = pmdp_get(args->pmdp); 264 WARN_ON(!(pmd_write(pmd) && pmd_dirty(pmd))); 265 pmdp_huge_get_and_clear_full(args->vma, vaddr, args->pmdp, 1); 266 pmd = pmdp_get(args->pmdp); 267 WARN_ON(!pmd_none(pmd)); 268 269 pmd = pmd_mkhuge(pfn_pmd(args->pmd_pfn, args->page_prot)); 270 pmd = pmd_mkyoung(pmd); 271 set_pmd_at(args->mm, vaddr, args->pmdp, pmd); 272 flush_dcache_page(page); 273 pmdp_test_and_clear_young(args->vma, vaddr, args->pmdp); 274 pmd = pmdp_get(args->pmdp); 275 WARN_ON(pmd_young(pmd)); 276 277 /* Clear the pte entries */ 278 pmdp_huge_get_and_clear(args->mm, vaddr, args->pmdp); 279 pgtable_trans_huge_withdraw(args->mm, args->pmdp); 280} 281 282static void __init pmd_leaf_tests(struct pgtable_debug_args *args) 283{ 284 pmd_t pmd; 285 286 if (!has_transparent_hugepage()) 287 return; 288 289 pr_debug("Validating PMD leaf\n"); 290 pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot); 291 292 /* 293 * PMD based THP is a leaf entry. 294 */ 295 pmd = pmd_mkhuge(pmd); 296 WARN_ON(!pmd_leaf(pmd)); 297} 298 299#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD 300static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx) 301{ 302 pgprot_t prot = vm_get_page_prot(idx); 303 unsigned long val = idx, *ptr = &val; 304 pud_t pud; 305 306 if (!has_transparent_pud_hugepage()) 307 return; 308 309 pr_debug("Validating PUD basic (%pGv)\n", ptr); 310 pud = pfn_pud(args->fixed_pud_pfn, prot); 311 312 /* 313 * This test needs to be executed after the given page table entry 314 * is created with pfn_pud() to make sure that vm_get_page_prot(idx) 315 * does not have the dirty bit enabled from the beginning. This is 316 * important for platforms like arm64 where (!PTE_RDONLY) indicate 317 * dirty bit being set. 318 */ 319 WARN_ON(pud_dirty(pud_wrprotect(pud))); 320 321 WARN_ON(!pud_same(pud, pud)); 322 WARN_ON(!pud_young(pud_mkyoung(pud_mkold(pud)))); 323 WARN_ON(!pud_dirty(pud_mkdirty(pud_mkclean(pud)))); 324 WARN_ON(pud_dirty(pud_mkclean(pud_mkdirty(pud)))); 325 WARN_ON(!pud_write(pud_mkwrite(pud_wrprotect(pud)))); 326 WARN_ON(pud_write(pud_wrprotect(pud_mkwrite(pud)))); 327 WARN_ON(pud_young(pud_mkold(pud_mkyoung(pud)))); 328 WARN_ON(pud_dirty(pud_wrprotect(pud_mkclean(pud)))); 329 WARN_ON(!pud_dirty(pud_wrprotect(pud_mkdirty(pud)))); 330 331 if (mm_pmd_folded(args->mm)) 332 return; 333 334 /* 335 * A huge page does not point to next level page table 336 * entry. Hence this must qualify as pud_bad(). 337 */ 338 WARN_ON(!pud_bad(pud_mkhuge(pud))); 339} 340 341static void __init pud_advanced_tests(struct pgtable_debug_args *args) 342{ 343 struct page *page; 344 unsigned long vaddr = args->vaddr; 345 pud_t pud; 346 347 if (!has_transparent_pud_hugepage()) 348 return; 349 350 page = (args->pud_pfn != ULONG_MAX) ? pfn_to_page(args->pud_pfn) : NULL; 351 if (!page) 352 return; 353 354 /* 355 * flush_dcache_page() is called after set_pud_at() to clear 356 * PG_arch_1 for the page on ARM64. The page flag isn't cleared 357 * when it's released and page allocation check will fail when 358 * the page is allocated again. For architectures other than ARM64, 359 * the unexpected overhead of cache flushing is acceptable. 360 */ 361 pr_debug("Validating PUD advanced\n"); 362 /* Align the address wrt HPAGE_PUD_SIZE */ 363 vaddr &= HPAGE_PUD_MASK; 364 365 pud = pfn_pud(args->pud_pfn, args->page_prot); 366 set_pud_at(args->mm, vaddr, args->pudp, pud); 367 flush_dcache_page(page); 368 pudp_set_wrprotect(args->mm, vaddr, args->pudp); 369 pud = pudp_get(args->pudp); 370 WARN_ON(pud_write(pud)); 371 372#ifndef __PAGETABLE_PMD_FOLDED 373 pudp_huge_get_and_clear(args->mm, vaddr, args->pudp); 374 pud = pudp_get(args->pudp); 375 WARN_ON(!pud_none(pud)); 376#endif /* __PAGETABLE_PMD_FOLDED */ 377 pud = pfn_pud(args->pud_pfn, args->page_prot); 378 pud = pud_wrprotect(pud); 379 pud = pud_mkclean(pud); 380 set_pud_at(args->mm, vaddr, args->pudp, pud); 381 flush_dcache_page(page); 382 pud = pud_mkwrite(pud); 383 pud = pud_mkdirty(pud); 384 pudp_set_access_flags(args->vma, vaddr, args->pudp, pud, 1); 385 pud = pudp_get(args->pudp); 386 WARN_ON(!(pud_write(pud) && pud_dirty(pud))); 387 388#ifndef __PAGETABLE_PMD_FOLDED 389 pudp_huge_get_and_clear_full(args->vma, vaddr, args->pudp, 1); 390 pud = pudp_get(args->pudp); 391 WARN_ON(!pud_none(pud)); 392#endif /* __PAGETABLE_PMD_FOLDED */ 393 394 pud = pfn_pud(args->pud_pfn, args->page_prot); 395 pud = pud_mkyoung(pud); 396 set_pud_at(args->mm, vaddr, args->pudp, pud); 397 flush_dcache_page(page); 398 pudp_test_and_clear_young(args->vma, vaddr, args->pudp); 399 pud = pudp_get(args->pudp); 400 WARN_ON(pud_young(pud)); 401 402 pudp_huge_get_and_clear(args->mm, vaddr, args->pudp); 403} 404 405static void __init pud_leaf_tests(struct pgtable_debug_args *args) 406{ 407 pud_t pud; 408 409 if (!has_transparent_pud_hugepage()) 410 return; 411 412 pr_debug("Validating PUD leaf\n"); 413 pud = pfn_pud(args->fixed_pud_pfn, args->page_prot); 414 /* 415 * PUD based THP is a leaf entry. 416 */ 417 pud = pud_mkhuge(pud); 418 WARN_ON(!pud_leaf(pud)); 419} 420#else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ 421static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx) { } 422static void __init pud_advanced_tests(struct pgtable_debug_args *args) { } 423static void __init pud_leaf_tests(struct pgtable_debug_args *args) { } 424#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ 425#else /* !CONFIG_TRANSPARENT_HUGEPAGE */ 426static void __init pmd_basic_tests(struct pgtable_debug_args *args, int idx) { } 427static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx) { } 428static void __init pmd_advanced_tests(struct pgtable_debug_args *args) { } 429static void __init pud_advanced_tests(struct pgtable_debug_args *args) { } 430static void __init pmd_leaf_tests(struct pgtable_debug_args *args) { } 431static void __init pud_leaf_tests(struct pgtable_debug_args *args) { } 432#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 433 434#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP 435static void __init pmd_huge_tests(struct pgtable_debug_args *args) 436{ 437 pmd_t pmd; 438 439 if (!arch_vmap_pmd_supported(args->page_prot) || 440 args->fixed_alignment < PMD_SIZE) 441 return; 442 443 pr_debug("Validating PMD huge\n"); 444 /* 445 * X86 defined pmd_set_huge() verifies that the given 446 * PMD is not a populated non-leaf entry. 447 */ 448 WRITE_ONCE(*args->pmdp, __pmd(0)); 449 WARN_ON(!pmd_set_huge(args->pmdp, __pfn_to_phys(args->fixed_pmd_pfn), args->page_prot)); 450 WARN_ON(!pmd_clear_huge(args->pmdp)); 451 pmd = pmdp_get(args->pmdp); 452 WARN_ON(!pmd_none(pmd)); 453} 454 455static void __init pud_huge_tests(struct pgtable_debug_args *args) 456{ 457 pud_t pud; 458 459 if (!arch_vmap_pud_supported(args->page_prot) || 460 args->fixed_alignment < PUD_SIZE) 461 return; 462 463 pr_debug("Validating PUD huge\n"); 464 /* 465 * X86 defined pud_set_huge() verifies that the given 466 * PUD is not a populated non-leaf entry. 467 */ 468 WRITE_ONCE(*args->pudp, __pud(0)); 469 WARN_ON(!pud_set_huge(args->pudp, __pfn_to_phys(args->fixed_pud_pfn), args->page_prot)); 470 WARN_ON(!pud_clear_huge(args->pudp)); 471 pud = pudp_get(args->pudp); 472 WARN_ON(!pud_none(pud)); 473} 474#else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */ 475static void __init pmd_huge_tests(struct pgtable_debug_args *args) { } 476static void __init pud_huge_tests(struct pgtable_debug_args *args) { } 477#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */ 478 479static void __init p4d_basic_tests(struct pgtable_debug_args *args) 480{ 481 p4d_t p4d; 482 483 pr_debug("Validating P4D basic\n"); 484 memset(&p4d, RANDOM_NZVALUE, sizeof(p4d_t)); 485 WARN_ON(!p4d_same(p4d, p4d)); 486} 487 488static void __init pgd_basic_tests(struct pgtable_debug_args *args) 489{ 490 pgd_t pgd; 491 492 pr_debug("Validating PGD basic\n"); 493 memset(&pgd, RANDOM_NZVALUE, sizeof(pgd_t)); 494 WARN_ON(!pgd_same(pgd, pgd)); 495} 496 497#ifndef __PAGETABLE_PUD_FOLDED 498static void __init pud_clear_tests(struct pgtable_debug_args *args) 499{ 500 pud_t pud = pudp_get(args->pudp); 501 502 if (mm_pmd_folded(args->mm)) 503 return; 504 505 pr_debug("Validating PUD clear\n"); 506 WARN_ON(pud_none(pud)); 507 pud_clear(args->pudp); 508 pud = pudp_get(args->pudp); 509 WARN_ON(!pud_none(pud)); 510} 511 512static void __init pud_populate_tests(struct pgtable_debug_args *args) 513{ 514 pud_t pud; 515 516 if (mm_pmd_folded(args->mm)) 517 return; 518 519 pr_debug("Validating PUD populate\n"); 520 /* 521 * This entry points to next level page table page. 522 * Hence this must not qualify as pud_bad(). 523 */ 524 pud_populate(args->mm, args->pudp, args->start_pmdp); 525 pud = pudp_get(args->pudp); 526 WARN_ON(pud_bad(pud)); 527} 528#else /* !__PAGETABLE_PUD_FOLDED */ 529static void __init pud_clear_tests(struct pgtable_debug_args *args) { } 530static void __init pud_populate_tests(struct pgtable_debug_args *args) { } 531#endif /* PAGETABLE_PUD_FOLDED */ 532 533#ifndef __PAGETABLE_P4D_FOLDED 534static void __init p4d_clear_tests(struct pgtable_debug_args *args) 535{ 536 p4d_t p4d = p4dp_get(args->p4dp); 537 538 if (mm_pud_folded(args->mm)) 539 return; 540 541 pr_debug("Validating P4D clear\n"); 542 WARN_ON(p4d_none(p4d)); 543 p4d_clear(args->p4dp); 544 p4d = p4dp_get(args->p4dp); 545 WARN_ON(!p4d_none(p4d)); 546} 547 548static void __init p4d_populate_tests(struct pgtable_debug_args *args) 549{ 550 p4d_t p4d; 551 552 if (mm_pud_folded(args->mm)) 553 return; 554 555 pr_debug("Validating P4D populate\n"); 556 /* 557 * This entry points to next level page table page. 558 * Hence this must not qualify as p4d_bad(). 559 */ 560 pud_clear(args->pudp); 561 p4d_clear(args->p4dp); 562 p4d_populate(args->mm, args->p4dp, args->start_pudp); 563 p4d = p4dp_get(args->p4dp); 564 WARN_ON(p4d_bad(p4d)); 565} 566 567static void __init pgd_clear_tests(struct pgtable_debug_args *args) 568{ 569 pgd_t pgd = pgdp_get(args->pgdp); 570 571 if (mm_p4d_folded(args->mm)) 572 return; 573 574 pr_debug("Validating PGD clear\n"); 575 WARN_ON(pgd_none(pgd)); 576 pgd_clear(args->pgdp); 577 pgd = pgdp_get(args->pgdp); 578 WARN_ON(!pgd_none(pgd)); 579} 580 581static void __init pgd_populate_tests(struct pgtable_debug_args *args) 582{ 583 pgd_t pgd; 584 585 if (mm_p4d_folded(args->mm)) 586 return; 587 588 pr_debug("Validating PGD populate\n"); 589 /* 590 * This entry points to next level page table page. 591 * Hence this must not qualify as pgd_bad(). 592 */ 593 p4d_clear(args->p4dp); 594 pgd_clear(args->pgdp); 595 pgd_populate(args->mm, args->pgdp, args->start_p4dp); 596 pgd = pgdp_get(args->pgdp); 597 WARN_ON(pgd_bad(pgd)); 598} 599#else /* !__PAGETABLE_P4D_FOLDED */ 600static void __init p4d_clear_tests(struct pgtable_debug_args *args) { } 601static void __init pgd_clear_tests(struct pgtable_debug_args *args) { } 602static void __init p4d_populate_tests(struct pgtable_debug_args *args) { } 603static void __init pgd_populate_tests(struct pgtable_debug_args *args) { } 604#endif /* PAGETABLE_P4D_FOLDED */ 605 606static void __init pte_clear_tests(struct pgtable_debug_args *args) 607{ 608 struct page *page; 609 pte_t pte = pfn_pte(args->pte_pfn, args->page_prot); 610 611 page = (args->pte_pfn != ULONG_MAX) ? pfn_to_page(args->pte_pfn) : NULL; 612 if (!page) 613 return; 614 615 /* 616 * flush_dcache_page() is called after set_pte_at() to clear 617 * PG_arch_1 for the page on ARM64. The page flag isn't cleared 618 * when it's released and page allocation check will fail when 619 * the page is allocated again. For architectures other than ARM64, 620 * the unexpected overhead of cache flushing is acceptable. 621 */ 622 pr_debug("Validating PTE clear\n"); 623 if (WARN_ON(!args->ptep)) 624 return; 625 626 set_pte_at(args->mm, args->vaddr, args->ptep, pte); 627 WARN_ON(pte_none(pte)); 628 flush_dcache_page(page); 629 barrier(); 630 ptep_clear(args->mm, args->vaddr, args->ptep); 631 pte = ptep_get(args->ptep); 632 WARN_ON(!pte_none(pte)); 633} 634 635static void __init pmd_clear_tests(struct pgtable_debug_args *args) 636{ 637 pmd_t pmd = pmdp_get(args->pmdp); 638 639 pr_debug("Validating PMD clear\n"); 640 WARN_ON(pmd_none(pmd)); 641 pmd_clear(args->pmdp); 642 pmd = pmdp_get(args->pmdp); 643 WARN_ON(!pmd_none(pmd)); 644} 645 646static void __init pmd_populate_tests(struct pgtable_debug_args *args) 647{ 648 pmd_t pmd; 649 650 pr_debug("Validating PMD populate\n"); 651 /* 652 * This entry points to next level page table page. 653 * Hence this must not qualify as pmd_bad(). 654 */ 655 pmd_populate(args->mm, args->pmdp, args->start_ptep); 656 pmd = pmdp_get(args->pmdp); 657 WARN_ON(pmd_bad(pmd)); 658} 659 660static void __init pte_special_tests(struct pgtable_debug_args *args) 661{ 662 pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot); 663 664 if (!IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL)) 665 return; 666 667 pr_debug("Validating PTE special\n"); 668 WARN_ON(!pte_special(pte_mkspecial(pte))); 669} 670 671static void __init pte_protnone_tests(struct pgtable_debug_args *args) 672{ 673 pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot_none); 674 675 if (!IS_ENABLED(CONFIG_NUMA_BALANCING)) 676 return; 677 678 pr_debug("Validating PTE protnone\n"); 679 WARN_ON(!pte_protnone(pte)); 680 WARN_ON(!pte_present(pte)); 681} 682 683#ifdef CONFIG_TRANSPARENT_HUGEPAGE 684static void __init pmd_protnone_tests(struct pgtable_debug_args *args) 685{ 686 pmd_t pmd; 687 688 if (!IS_ENABLED(CONFIG_NUMA_BALANCING)) 689 return; 690 691 if (!has_transparent_hugepage()) 692 return; 693 694 pr_debug("Validating PMD protnone\n"); 695 pmd = pmd_mkhuge(pfn_pmd(args->fixed_pmd_pfn, args->page_prot_none)); 696 WARN_ON(!pmd_protnone(pmd)); 697 WARN_ON(!pmd_present(pmd)); 698} 699#else /* !CONFIG_TRANSPARENT_HUGEPAGE */ 700static void __init pmd_protnone_tests(struct pgtable_debug_args *args) { } 701#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 702 703static void __init pte_soft_dirty_tests(struct pgtable_debug_args *args) 704{ 705 pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot); 706 707 if (!pgtable_supports_soft_dirty()) 708 return; 709 710 pr_debug("Validating PTE soft dirty\n"); 711 WARN_ON(!pte_soft_dirty(pte_mksoft_dirty(pte))); 712 WARN_ON(pte_soft_dirty(pte_clear_soft_dirty(pte))); 713} 714 715static void __init pte_swap_soft_dirty_tests(struct pgtable_debug_args *args) 716{ 717 pte_t pte; 718 softleaf_t entry; 719 720 if (!pgtable_supports_soft_dirty()) 721 return; 722 723 pr_debug("Validating PTE swap soft dirty\n"); 724 pte = swp_entry_to_pte(args->swp_entry); 725 entry = softleaf_from_pte(pte); 726 727 WARN_ON(!softleaf_is_swap(entry)); 728 WARN_ON(!pte_swp_soft_dirty(pte_swp_mksoft_dirty(pte))); 729 WARN_ON(pte_swp_soft_dirty(pte_swp_clear_soft_dirty(pte))); 730} 731 732#ifdef CONFIG_TRANSPARENT_HUGEPAGE 733static void __init pmd_soft_dirty_tests(struct pgtable_debug_args *args) 734{ 735 pmd_t pmd; 736 737 if (!pgtable_supports_soft_dirty()) 738 return; 739 740 if (!has_transparent_hugepage()) 741 return; 742 743 pr_debug("Validating PMD soft dirty\n"); 744 pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot); 745 WARN_ON(!pmd_soft_dirty(pmd_mksoft_dirty(pmd))); 746 WARN_ON(pmd_soft_dirty(pmd_clear_soft_dirty(pmd))); 747} 748 749static void __init pmd_leaf_soft_dirty_tests(struct pgtable_debug_args *args) 750{ 751 pmd_t pmd; 752 753 if (!pgtable_supports_soft_dirty() || 754 !IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION)) 755 return; 756 757 if (!has_transparent_hugepage()) 758 return; 759 760 pr_debug("Validating PMD swap soft dirty\n"); 761 pmd = swp_entry_to_pmd(args->leaf_entry); 762 WARN_ON(!pmd_is_huge(pmd)); 763 WARN_ON(!pmd_is_valid_softleaf(pmd)); 764 765 WARN_ON(!pmd_swp_soft_dirty(pmd_swp_mksoft_dirty(pmd))); 766 WARN_ON(pmd_swp_soft_dirty(pmd_swp_clear_soft_dirty(pmd))); 767} 768#else /* !CONFIG_TRANSPARENT_HUGEPAGE */ 769static void __init pmd_soft_dirty_tests(struct pgtable_debug_args *args) { } 770static void __init pmd_leaf_soft_dirty_tests(struct pgtable_debug_args *args) { } 771#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 772 773static void __init pte_swap_exclusive_tests(struct pgtable_debug_args *args) 774{ 775 swp_entry_t entry; 776 softleaf_t softleaf; 777 pte_t pte; 778 779 pr_debug("Validating PTE swap exclusive\n"); 780 entry = args->swp_entry; 781 782 pte = swp_entry_to_pte(entry); 783 softleaf = softleaf_from_pte(pte); 784 785 WARN_ON(pte_swp_exclusive(pte)); 786 WARN_ON(!softleaf_is_swap(softleaf)); 787 WARN_ON(memcmp(&entry, &softleaf, sizeof(entry))); 788 789 pte = pte_swp_mkexclusive(pte); 790 softleaf = softleaf_from_pte(pte); 791 792 WARN_ON(!pte_swp_exclusive(pte)); 793 WARN_ON(!softleaf_is_swap(softleaf)); 794 WARN_ON(pte_swp_soft_dirty(pte)); 795 WARN_ON(memcmp(&entry, &softleaf, sizeof(entry))); 796 797 pte = pte_swp_clear_exclusive(pte); 798 softleaf = softleaf_from_pte(pte); 799 800 WARN_ON(pte_swp_exclusive(pte)); 801 WARN_ON(!softleaf_is_swap(softleaf)); 802 WARN_ON(memcmp(&entry, &softleaf, sizeof(entry))); 803} 804 805static void __init pte_swap_tests(struct pgtable_debug_args *args) 806{ 807 swp_entry_t arch_entry; 808 softleaf_t entry; 809 pte_t pte1, pte2; 810 811 pr_debug("Validating PTE swap\n"); 812 pte1 = swp_entry_to_pte(args->swp_entry); 813 entry = softleaf_from_pte(pte1); 814 815 WARN_ON(!softleaf_is_swap(entry)); 816 817 arch_entry = __pte_to_swp_entry(pte1); 818 pte2 = __swp_entry_to_pte(arch_entry); 819 WARN_ON(memcmp(&pte1, &pte2, sizeof(pte1))); 820} 821 822#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION 823static void __init pmd_softleaf_tests(struct pgtable_debug_args *args) 824{ 825 swp_entry_t arch_entry; 826 pmd_t pmd1, pmd2; 827 828 if (!has_transparent_hugepage()) 829 return; 830 831 pr_debug("Validating PMD swap\n"); 832 pmd1 = swp_entry_to_pmd(args->leaf_entry); 833 WARN_ON(!pmd_is_huge(pmd1)); 834 WARN_ON(!pmd_is_valid_softleaf(pmd1)); 835 836 arch_entry = __pmd_to_swp_entry(pmd1); 837 pmd2 = __swp_entry_to_pmd(arch_entry); 838 WARN_ON(memcmp(&pmd1, &pmd2, sizeof(pmd1))); 839} 840#else /* !CONFIG_ARCH_ENABLE_THP_MIGRATION */ 841static void __init pmd_softleaf_tests(struct pgtable_debug_args *args) { } 842#endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */ 843 844static void __init swap_migration_tests(struct pgtable_debug_args *args) 845{ 846 struct page *page; 847 softleaf_t entry; 848 849 if (!IS_ENABLED(CONFIG_MIGRATION)) 850 return; 851 852 /* 853 * swap_migration_tests() requires a dedicated page as it needs to 854 * be locked before creating a migration entry from it. Locking the 855 * page that actually maps kernel text ('start_kernel') can be real 856 * problematic. Lets use the allocated page explicitly for this 857 * purpose. 858 */ 859 page = (args->pte_pfn != ULONG_MAX) ? pfn_to_page(args->pte_pfn) : NULL; 860 if (!page) 861 return; 862 863 pr_debug("Validating swap migration\n"); 864 865 /* 866 * make_[readable|writable]_migration_entry() expects given page to 867 * be locked, otherwise it stumbles upon a BUG_ON(). 868 */ 869 __SetPageLocked(page); 870 entry = make_writable_migration_entry(page_to_pfn(page)); 871 WARN_ON(!softleaf_is_migration(entry)); 872 WARN_ON(!softleaf_is_migration_write(entry)); 873 874 entry = make_readable_migration_entry(swp_offset(entry)); 875 WARN_ON(!softleaf_is_migration(entry)); 876 WARN_ON(softleaf_is_migration_write(entry)); 877 878 entry = make_readable_migration_entry(page_to_pfn(page)); 879 WARN_ON(!softleaf_is_migration(entry)); 880 WARN_ON(softleaf_is_migration_write(entry)); 881 __ClearPageLocked(page); 882} 883 884#ifdef CONFIG_HUGETLB_PAGE 885static void __init hugetlb_basic_tests(struct pgtable_debug_args *args) 886{ 887 pte_t pte; 888 889 pr_debug("Validating HugeTLB basic\n"); 890 pte = pfn_pte(args->fixed_pmd_pfn, args->page_prot); 891 pte = arch_make_huge_pte(pte, PMD_SHIFT, VM_ACCESS_FLAGS); 892 893#ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB 894 WARN_ON(!pte_huge(pte)); 895#endif 896 WARN_ON(!huge_pte_dirty(huge_pte_mkdirty(pte))); 897 WARN_ON(!huge_pte_write(huge_pte_mkwrite(huge_pte_wrprotect(pte)))); 898 WARN_ON(huge_pte_write(huge_pte_wrprotect(huge_pte_mkwrite(pte)))); 899} 900#else /* !CONFIG_HUGETLB_PAGE */ 901static void __init hugetlb_basic_tests(struct pgtable_debug_args *args) { } 902#endif /* CONFIG_HUGETLB_PAGE */ 903 904#ifdef CONFIG_TRANSPARENT_HUGEPAGE 905static void __init pmd_thp_tests(struct pgtable_debug_args *args) 906{ 907 pmd_t pmd; 908 909 if (!has_transparent_hugepage()) 910 return; 911 912 pr_debug("Validating PMD based THP\n"); 913 /* 914 * pmd_trans_huge() and pmd_present() must return positive after 915 * MMU invalidation with pmd_mkinvalid(). This behavior is an 916 * optimization for transparent huge page. pmd_trans_huge() must 917 * be true if pmd_page() returns a valid THP to avoid taking the 918 * pmd_lock when others walk over non transhuge pmds (i.e. there 919 * are no THP allocated). Especially when splitting a THP and 920 * removing the present bit from the pmd, pmd_trans_huge() still 921 * needs to return true. pmd_present() should be true whenever 922 * pmd_trans_huge() returns true. 923 */ 924 pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot); 925 WARN_ON(!pmd_trans_huge(pmd_mkhuge(pmd))); 926 927#ifndef __HAVE_ARCH_PMDP_INVALIDATE 928 WARN_ON(!pmd_trans_huge(pmd_mkinvalid(pmd_mkhuge(pmd)))); 929 WARN_ON(!pmd_present(pmd_mkinvalid(pmd_mkhuge(pmd)))); 930 WARN_ON(!pmd_leaf(pmd_mkinvalid(pmd_mkhuge(pmd)))); 931#endif /* __HAVE_ARCH_PMDP_INVALIDATE */ 932} 933 934#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD 935static void __init pud_thp_tests(struct pgtable_debug_args *args) 936{ 937 pud_t pud; 938 939 if (!has_transparent_pud_hugepage()) 940 return; 941 942 pr_debug("Validating PUD based THP\n"); 943 pud = pfn_pud(args->fixed_pud_pfn, args->page_prot); 944 WARN_ON(!pud_trans_huge(pud_mkhuge(pud))); 945 946 /* 947 * pud_mkinvalid() has been dropped for now. Enable back 948 * these tests when it comes back with a modified pud_present(). 949 * 950 * WARN_ON(!pud_trans_huge(pud_mkinvalid(pud_mkhuge(pud)))); 951 * WARN_ON(!pud_present(pud_mkinvalid(pud_mkhuge(pud)))); 952 */ 953} 954#else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ 955static void __init pud_thp_tests(struct pgtable_debug_args *args) { } 956#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ 957#else /* !CONFIG_TRANSPARENT_HUGEPAGE */ 958static void __init pmd_thp_tests(struct pgtable_debug_args *args) { } 959static void __init pud_thp_tests(struct pgtable_debug_args *args) { } 960#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 961 962static unsigned long __init get_random_vaddr(void) 963{ 964 unsigned long random_vaddr, random_pages, total_user_pages; 965 966 total_user_pages = (TASK_SIZE - FIRST_USER_ADDRESS) / PAGE_SIZE; 967 968 random_pages = get_random_long() % total_user_pages; 969 random_vaddr = FIRST_USER_ADDRESS + random_pages * PAGE_SIZE; 970 971 return random_vaddr; 972} 973 974static void __init destroy_args(struct pgtable_debug_args *args) 975{ 976 struct page *page = NULL; 977 978 /* Free (huge) page */ 979 if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && 980 has_transparent_pud_hugepage() && 981 args->pud_pfn != ULONG_MAX) { 982 if (args->is_contiguous_page) { 983 free_contig_range(args->pud_pfn, 984 (1 << (HPAGE_PUD_SHIFT - PAGE_SHIFT))); 985 } else { 986 page = pfn_to_page(args->pud_pfn); 987 __free_pages(page, HPAGE_PUD_SHIFT - PAGE_SHIFT); 988 } 989 990 args->pud_pfn = ULONG_MAX; 991 args->pmd_pfn = ULONG_MAX; 992 args->pte_pfn = ULONG_MAX; 993 } 994 995 if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && 996 has_transparent_hugepage() && 997 args->pmd_pfn != ULONG_MAX) { 998 if (args->is_contiguous_page) { 999 free_contig_range(args->pmd_pfn, (1 << HPAGE_PMD_ORDER)); 1000 } else { 1001 page = pfn_to_page(args->pmd_pfn); 1002 __free_pages(page, HPAGE_PMD_ORDER); 1003 } 1004 1005 args->pmd_pfn = ULONG_MAX; 1006 args->pte_pfn = ULONG_MAX; 1007 } 1008 1009 if (args->pte_pfn != ULONG_MAX) { 1010 page = pfn_to_page(args->pte_pfn); 1011 __free_page(page); 1012 1013 args->pte_pfn = ULONG_MAX; 1014 } 1015 1016 /* Free page table entries */ 1017 if (args->start_ptep) { 1018 pmd_clear(args->pmdp); 1019 pte_free(args->mm, args->start_ptep); 1020 mm_dec_nr_ptes(args->mm); 1021 } 1022 1023 if (args->start_pmdp) { 1024 pud_clear(args->pudp); 1025 pmd_free(args->mm, args->start_pmdp); 1026 mm_dec_nr_pmds(args->mm); 1027 } 1028 1029 if (args->start_pudp) { 1030 p4d_clear(args->p4dp); 1031 pud_free(args->mm, args->start_pudp); 1032 mm_dec_nr_puds(args->mm); 1033 } 1034 1035 if (args->start_p4dp) { 1036 pgd_clear(args->pgdp); 1037 p4d_free(args->mm, args->start_p4dp); 1038 } 1039 1040 /* Free vma and mm struct */ 1041 if (args->vma) 1042 vm_area_free(args->vma); 1043 1044 if (args->mm) 1045 mmput(args->mm); 1046} 1047 1048static struct page * __init 1049debug_vm_pgtable_alloc_huge_page(struct pgtable_debug_args *args, int order) 1050{ 1051 struct page *page = NULL; 1052 1053#ifdef CONFIG_CONTIG_ALLOC 1054 if (order > MAX_PAGE_ORDER) { 1055 page = alloc_contig_pages((1 << order), GFP_KERNEL, 1056 first_online_node, NULL); 1057 if (page) { 1058 args->is_contiguous_page = true; 1059 return page; 1060 } 1061 } 1062#endif 1063 1064 if (order <= MAX_PAGE_ORDER) 1065 page = alloc_pages(GFP_KERNEL, order); 1066 1067 return page; 1068} 1069 1070/* 1071 * Check if a physical memory range described by <pstart, pend> contains 1072 * an area that is of size psize, and aligned to psize. 1073 * 1074 * Don't use address 0, an all-zeroes physical address might mask bugs, and 1075 * it's not used on x86. 1076 */ 1077static void __init phys_align_check(phys_addr_t pstart, 1078 phys_addr_t pend, unsigned long psize, 1079 phys_addr_t *physp, unsigned long *alignp) 1080{ 1081 phys_addr_t aligned_start, aligned_end; 1082 1083 if (pstart == 0) 1084 pstart = PAGE_SIZE; 1085 1086 aligned_start = ALIGN(pstart, psize); 1087 aligned_end = aligned_start + psize; 1088 1089 if (aligned_end > aligned_start && aligned_end <= pend) { 1090 *alignp = psize; 1091 *physp = aligned_start; 1092 } 1093} 1094 1095static void __init init_fixed_pfns(struct pgtable_debug_args *args) 1096{ 1097 u64 idx; 1098 phys_addr_t phys, pstart, pend; 1099 1100 /* 1101 * Initialize the fixed pfns. To do this, try to find a 1102 * valid physical range, preferably aligned to PUD_SIZE, 1103 * but settling for aligned to PMD_SIZE as a fallback. If 1104 * neither of those is found, use the physical address of 1105 * the start_kernel symbol. 1106 * 1107 * The memory doesn't need to be allocated, it just needs to exist 1108 * as usable memory. It won't be touched. 1109 * 1110 * The alignment is recorded, and can be checked to see if we 1111 * can run the tests that require an actual valid physical 1112 * address range on some architectures ({pmd,pud}_huge_test 1113 * on x86). 1114 */ 1115 1116 phys = __pa_symbol(&start_kernel); 1117 args->fixed_alignment = PAGE_SIZE; 1118 1119 for_each_mem_range(idx, &pstart, &pend) { 1120 /* First check for a PUD-aligned area */ 1121 phys_align_check(pstart, pend, PUD_SIZE, &phys, 1122 &args->fixed_alignment); 1123 1124 /* If a PUD-aligned area is found, we're done */ 1125 if (args->fixed_alignment == PUD_SIZE) 1126 break; 1127 1128 /* 1129 * If no PMD-aligned area found yet, check for one, 1130 * but continue the loop to look for a PUD-aligned area. 1131 */ 1132 if (args->fixed_alignment < PMD_SIZE) 1133 phys_align_check(pstart, pend, PMD_SIZE, &phys, 1134 &args->fixed_alignment); 1135 } 1136 1137 args->fixed_pgd_pfn = __phys_to_pfn(phys & PGDIR_MASK); 1138 args->fixed_p4d_pfn = __phys_to_pfn(phys & P4D_MASK); 1139 args->fixed_pud_pfn = __phys_to_pfn(phys & PUD_MASK); 1140 args->fixed_pmd_pfn = __phys_to_pfn(phys & PMD_MASK); 1141 args->fixed_pte_pfn = __phys_to_pfn(phys & PAGE_MASK); 1142 WARN_ON(!pfn_valid(args->fixed_pte_pfn)); 1143} 1144 1145 1146static int __init init_args(struct pgtable_debug_args *args) 1147{ 1148 unsigned long max_swap_offset; 1149 struct page *page = NULL; 1150 int ret = 0; 1151 1152 /* 1153 * Initialize the debugging data. 1154 * 1155 * vm_get_page_prot(VM_NONE) or vm_get_page_prot(VM_SHARED|VM_NONE) 1156 * will help create page table entries with PROT_NONE permission as 1157 * required for pxx_protnone_tests(). 1158 */ 1159 memset(args, 0, sizeof(*args)); 1160 args->vaddr = get_random_vaddr(); 1161 args->page_prot = vm_get_page_prot(VM_ACCESS_FLAGS); 1162 args->page_prot_none = vm_get_page_prot(VM_NONE); 1163 args->is_contiguous_page = false; 1164 args->pud_pfn = ULONG_MAX; 1165 args->pmd_pfn = ULONG_MAX; 1166 args->pte_pfn = ULONG_MAX; 1167 args->fixed_pgd_pfn = ULONG_MAX; 1168 args->fixed_p4d_pfn = ULONG_MAX; 1169 args->fixed_pud_pfn = ULONG_MAX; 1170 args->fixed_pmd_pfn = ULONG_MAX; 1171 args->fixed_pte_pfn = ULONG_MAX; 1172 1173 /* Allocate mm and vma */ 1174 args->mm = mm_alloc(); 1175 if (!args->mm) { 1176 pr_err("Failed to allocate mm struct\n"); 1177 ret = -ENOMEM; 1178 goto error; 1179 } 1180 1181 args->vma = vm_area_alloc(args->mm); 1182 if (!args->vma) { 1183 pr_err("Failed to allocate vma\n"); 1184 ret = -ENOMEM; 1185 goto error; 1186 } 1187 1188 /* 1189 * Allocate page table entries. They will be modified in the tests. 1190 * Lets save the page table entries so that they can be released 1191 * when the tests are completed. 1192 */ 1193 args->pgdp = pgd_offset(args->mm, args->vaddr); 1194 args->p4dp = p4d_alloc(args->mm, args->pgdp, args->vaddr); 1195 if (!args->p4dp) { 1196 pr_err("Failed to allocate p4d entries\n"); 1197 ret = -ENOMEM; 1198 goto error; 1199 } 1200 args->start_p4dp = p4d_offset(args->pgdp, 0UL); 1201 WARN_ON(!args->start_p4dp); 1202 1203 args->pudp = pud_alloc(args->mm, args->p4dp, args->vaddr); 1204 if (!args->pudp) { 1205 pr_err("Failed to allocate pud entries\n"); 1206 ret = -ENOMEM; 1207 goto error; 1208 } 1209 args->start_pudp = pud_offset(args->p4dp, 0UL); 1210 WARN_ON(!args->start_pudp); 1211 1212 args->pmdp = pmd_alloc(args->mm, args->pudp, args->vaddr); 1213 if (!args->pmdp) { 1214 pr_err("Failed to allocate pmd entries\n"); 1215 ret = -ENOMEM; 1216 goto error; 1217 } 1218 args->start_pmdp = pmd_offset(args->pudp, 0UL); 1219 WARN_ON(!args->start_pmdp); 1220 1221 if (pte_alloc(args->mm, args->pmdp)) { 1222 pr_err("Failed to allocate pte entries\n"); 1223 ret = -ENOMEM; 1224 goto error; 1225 } 1226 args->start_ptep = pmd_pgtable(pmdp_get(args->pmdp)); 1227 WARN_ON(!args->start_ptep); 1228 1229 init_fixed_pfns(args); 1230 1231 /* See generic_max_swapfile_size(): probe the maximum offset */ 1232 max_swap_offset = swp_offset(softleaf_from_pte(softleaf_to_pte(swp_entry(0, ~0UL)))); 1233 /* Create a swp entry with all possible bits set while still being swap. */ 1234 args->swp_entry = swp_entry(MAX_SWAPFILES - 1, max_swap_offset); 1235 /* Create a non-present migration entry. */ 1236 args->leaf_entry = make_writable_migration_entry(~0UL); 1237 1238 /* 1239 * Allocate (huge) pages because some of the tests need to access 1240 * the data in the pages. The corresponding tests will be skipped 1241 * if we fail to allocate (huge) pages. 1242 */ 1243 if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && 1244 has_transparent_pud_hugepage()) { 1245 page = debug_vm_pgtable_alloc_huge_page(args, 1246 HPAGE_PUD_SHIFT - PAGE_SHIFT); 1247 if (page) { 1248 args->pud_pfn = page_to_pfn(page); 1249 args->pmd_pfn = args->pud_pfn; 1250 args->pte_pfn = args->pud_pfn; 1251 return 0; 1252 } 1253 } 1254 1255 if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && 1256 has_transparent_hugepage()) { 1257 page = debug_vm_pgtable_alloc_huge_page(args, HPAGE_PMD_ORDER); 1258 if (page) { 1259 args->pmd_pfn = page_to_pfn(page); 1260 args->pte_pfn = args->pmd_pfn; 1261 return 0; 1262 } 1263 } 1264 1265 page = alloc_page(GFP_KERNEL); 1266 if (page) 1267 args->pte_pfn = page_to_pfn(page); 1268 1269 return 0; 1270 1271error: 1272 destroy_args(args); 1273 return ret; 1274} 1275 1276static int __init debug_vm_pgtable(void) 1277{ 1278 struct pgtable_debug_args args; 1279 spinlock_t *ptl = NULL; 1280 int idx, ret; 1281 1282 pr_info("Validating architecture page table helpers\n"); 1283 ret = init_args(&args); 1284 if (ret) 1285 return ret; 1286 1287 /* 1288 * Iterate over each possible vm_flags to make sure that all 1289 * the basic page table transformation validations just hold 1290 * true irrespective of the starting protection value for a 1291 * given page table entry. 1292 * 1293 * Protection based vm_flags combinations are always linear 1294 * and increasing i.e starting from VM_NONE and going up to 1295 * (VM_SHARED | READ | WRITE | EXEC). 1296 */ 1297#define VM_FLAGS_START (VM_NONE) 1298#define VM_FLAGS_END (VM_SHARED | VM_EXEC | VM_WRITE | VM_READ) 1299 1300 for (idx = VM_FLAGS_START; idx <= VM_FLAGS_END; idx++) { 1301 pte_basic_tests(&args, idx); 1302 pmd_basic_tests(&args, idx); 1303 pud_basic_tests(&args, idx); 1304 } 1305 1306 /* 1307 * Both P4D and PGD level tests are very basic which do not 1308 * involve creating page table entries from the protection 1309 * value and the given pfn. Hence just keep them out from 1310 * the above iteration for now to save some test execution 1311 * time. 1312 */ 1313 p4d_basic_tests(&args); 1314 pgd_basic_tests(&args); 1315 1316 pmd_leaf_tests(&args); 1317 pud_leaf_tests(&args); 1318 1319 pte_special_tests(&args); 1320 pte_protnone_tests(&args); 1321 pmd_protnone_tests(&args); 1322 1323 pte_soft_dirty_tests(&args); 1324 pmd_soft_dirty_tests(&args); 1325 pte_swap_soft_dirty_tests(&args); 1326 pmd_leaf_soft_dirty_tests(&args); 1327 1328 pte_swap_exclusive_tests(&args); 1329 1330 pte_swap_tests(&args); 1331 pmd_softleaf_tests(&args); 1332 1333 swap_migration_tests(&args); 1334 1335 pmd_thp_tests(&args); 1336 pud_thp_tests(&args); 1337 1338 hugetlb_basic_tests(&args); 1339 1340 /* 1341 * Page table modifying tests. They need to hold 1342 * proper page table lock. 1343 */ 1344 1345 args.ptep = pte_offset_map_lock(args.mm, args.pmdp, args.vaddr, &ptl); 1346 pte_clear_tests(&args); 1347 pte_advanced_tests(&args); 1348 if (args.ptep) 1349 pte_unmap_unlock(args.ptep, ptl); 1350 1351 ptl = pmd_lock(args.mm, args.pmdp); 1352 pmd_clear_tests(&args); 1353 pmd_advanced_tests(&args); 1354 pmd_huge_tests(&args); 1355 pmd_populate_tests(&args); 1356 spin_unlock(ptl); 1357 1358 ptl = pud_lock(args.mm, args.pudp); 1359 pud_clear_tests(&args); 1360 pud_advanced_tests(&args); 1361 pud_huge_tests(&args); 1362 pud_populate_tests(&args); 1363 spin_unlock(ptl); 1364 1365 spin_lock(&(args.mm->page_table_lock)); 1366 p4d_clear_tests(&args); 1367 pgd_clear_tests(&args); 1368 p4d_populate_tests(&args); 1369 pgd_populate_tests(&args); 1370 spin_unlock(&(args.mm->page_table_lock)); 1371 1372 destroy_args(&args); 1373 return 0; 1374} 1375late_initcall(debug_vm_pgtable);
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