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/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 <linux/io.h>
  32 #include <asm/pgalloc.h>
  33 #include <asm/tlbflush.h>
  34
  35 /*
  36  * Please refer Documentation/vm/arch_pgtable_helpers.rst for the semantics
  37  * expectations that are being validated here. All future changes in here
  38  * or the documentation need to be in sync.
  39  */
  40
  41 #define VMFLAGS (VM_READ|VM_WRITE|VM_EXEC)
  42
  43 /*
  44  * On s390 platform, the lower 4 bits are used to identify given page table
  45  * entry type. But these bits might affect the ability to clear entries with
  46  * pxx_clear() because of how dynamic page table folding works on s390. So
  47  * while loading up the entries do not change the lower 4 bits. It does not
  48  * have affect any other platform. Also avoid the 62nd bit on ppc64 that is
  49  * used to mark a pte entry.
  50  */
  51 #define S390_SKIP_MASK          GENMASK(3, 0)
  52 #if __BITS_PER_LONG == 64
  53 #define PPC64_SKIP_MASK         GENMASK(62, 62)
  54 #else
  55 #define PPC64_SKIP_MASK         0x0
  56 #endif
  57 #define ARCH_SKIP_MASK (S390_SKIP_MASK | PPC64_SKIP_MASK)
  58 #define RANDOM_ORVALUE (GENMASK(BITS_PER_LONG - 1, 0) & ~ARCH_SKIP_MASK)
  59 #define RANDOM_NZVALUE  GENMASK(7, 0)
  60
  61 static void __init pte_basic_tests(unsigned long pfn, int idx)
  62 {
  63         pgprot_t prot = protection_map[idx];
  64         pte_t pte = pfn_pte(pfn, prot);
  65         unsigned long val = idx, *ptr = &val;
  66
  67         pr_debug("Validating PTE basic (%pGv)\n", ptr);
  68
  69         /*
  70          * This test needs to be executed after the given page table entry
  71          * is created with pfn_pte() to make sure that protection_map[idx]
  72          * does not have the dirty bit enabled from the beginning. This is
  73          * important for platforms like arm64 where (!PTE_RDONLY) indicate
  74          * dirty bit being set.
  75          */
  76         WARN_ON(pte_dirty(pte_wrprotect(pte)));
  77
  78         WARN_ON(!pte_same(pte, pte));
  79         WARN_ON(!pte_young(pte_mkyoung(pte_mkold(pte))));
  80         WARN_ON(!pte_dirty(pte_mkdirty(pte_mkclean(pte))));
  81         WARN_ON(!pte_write(pte_mkwrite(pte_wrprotect(pte))));
  82         WARN_ON(pte_young(pte_mkold(pte_mkyoung(pte))));
  83         WARN_ON(pte_dirty(pte_mkclean(pte_mkdirty(pte))));
  84         WARN_ON(pte_write(pte_wrprotect(pte_mkwrite(pte))));
  85         WARN_ON(pte_dirty(pte_wrprotect(pte_mkclean(pte))));
  86         WARN_ON(!pte_dirty(pte_wrprotect(pte_mkdirty(pte))));
  87 }
  88
  89 static void __init pte_advanced_tests(struct mm_struct *mm,
  90                                       struct vm_area_struct *vma, pte_t *ptep,
  91                                       unsigned long pfn, unsigned long vaddr,
  92                                       pgprot_t prot)
  93 {
  94         pte_t pte;
  95
  96         /*
  97          * Architectures optimize set_pte_at by avoiding TLB flush.
  98          * This requires set_pte_at to be not used to update an
  99          * existing pte entry. Clear pte before we do set_pte_at
 100          */
 101
 102         pr_debug("Validating PTE advanced\n");
 103         pte = pfn_pte(pfn, prot);
 104         set_pte_at(mm, vaddr, ptep, pte);
 105         ptep_set_wrprotect(mm, vaddr, ptep);
 106         pte = ptep_get(ptep);
 107         WARN_ON(pte_write(pte));
 108         ptep_get_and_clear(mm, vaddr, ptep);
 109         pte = ptep_get(ptep);
 110         WARN_ON(!pte_none(pte));
 111
 112         pte = pfn_pte(pfn, prot);
 113         pte = pte_wrprotect(pte);
 114         pte = pte_mkclean(pte);
 115         set_pte_at(mm, vaddr, ptep, pte);
 116         pte = pte_mkwrite(pte);
 117         pte = pte_mkdirty(pte);
 118         ptep_set_access_flags(vma, vaddr, ptep, pte, 1);
 119         pte = ptep_get(ptep);
 120         WARN_ON(!(pte_write(pte) && pte_dirty(pte)));
 121         ptep_get_and_clear_full(mm, vaddr, ptep, 1);
 122         pte = ptep_get(ptep);
 123         WARN_ON(!pte_none(pte));
 124
 125         pte = pfn_pte(pfn, prot);
 126         pte = pte_mkyoung(pte);
 127         set_pte_at(mm, vaddr, ptep, pte);
 128         ptep_test_and_clear_young(vma, vaddr, ptep);
 129         pte = ptep_get(ptep);
 130         WARN_ON(pte_young(pte));
 131 }
 132
 133 static void __init pte_savedwrite_tests(unsigned long pfn, pgprot_t prot)
 134 {
 135         pte_t pte = pfn_pte(pfn, prot);
 136
 137         if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
 138                 return;
 139
 140         pr_debug("Validating PTE saved write\n");
 141         WARN_ON(!pte_savedwrite(pte_mk_savedwrite(pte_clear_savedwrite(pte))));
 142         WARN_ON(pte_savedwrite(pte_clear_savedwrite(pte_mk_savedwrite(pte))));
 143 }
 144
 145 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 146 static void __init pmd_basic_tests(unsigned long pfn, int idx)
 147 {
 148         pgprot_t prot = protection_map[idx];
 149         unsigned long val = idx, *ptr = &val;
 150         pmd_t pmd;
 151
 152         if (!has_transparent_hugepage())
 153                 return;
 154
 155         pr_debug("Validating PMD basic (%pGv)\n", ptr);
 156         pmd = pfn_pmd(pfn, prot);
 157
 158         /*
 159          * This test needs to be executed after the given page table entry
 160          * is created with pfn_pmd() to make sure that protection_map[idx]
 161          * does not have the dirty bit enabled from the beginning. This is
 162          * important for platforms like arm64 where (!PTE_RDONLY) indicate
 163          * dirty bit being set.
 164          */
 165         WARN_ON(pmd_dirty(pmd_wrprotect(pmd)));
 166
 167
 168         WARN_ON(!pmd_same(pmd, pmd));
 169         WARN_ON(!pmd_young(pmd_mkyoung(pmd_mkold(pmd))));
 170         WARN_ON(!pmd_dirty(pmd_mkdirty(pmd_mkclean(pmd))));
 171         WARN_ON(!pmd_write(pmd_mkwrite(pmd_wrprotect(pmd))));
 172         WARN_ON(pmd_young(pmd_mkold(pmd_mkyoung(pmd))));
 173         WARN_ON(pmd_dirty(pmd_mkclean(pmd_mkdirty(pmd))));
 174         WARN_ON(pmd_write(pmd_wrprotect(pmd_mkwrite(pmd))));
 175         WARN_ON(pmd_dirty(pmd_wrprotect(pmd_mkclean(pmd))));
 176         WARN_ON(!pmd_dirty(pmd_wrprotect(pmd_mkdirty(pmd))));
 177         /*
 178          * A huge page does not point to next level page table
 179          * entry. Hence this must qualify as pmd_bad().
 180          */
 181         WARN_ON(!pmd_bad(pmd_mkhuge(pmd)));
 182 }
 183
 184 static void __init pmd_advanced_tests(struct mm_struct *mm,
 185                                       struct vm_area_struct *vma, pmd_t *pmdp,
 186                                       unsigned long pfn, unsigned long vaddr,
 187                                       pgprot_t prot, pgtable_t pgtable)
 188 {
 189         pmd_t pmd;
 190
 191         if (!has_transparent_hugepage())
 192                 return;
 193
 194         pr_debug("Validating PMD advanced\n");
 195         /* Align the address wrt HPAGE_PMD_SIZE */
 196         vaddr &= HPAGE_PMD_MASK;
 197
 198         pgtable_trans_huge_deposit(mm, pmdp, pgtable);
 199
 200         pmd = pfn_pmd(pfn, prot);
 201         set_pmd_at(mm, vaddr, pmdp, pmd);
 202         pmdp_set_wrprotect(mm, vaddr, pmdp);
 203         pmd = READ_ONCE(*pmdp);
 204         WARN_ON(pmd_write(pmd));
 205         pmdp_huge_get_and_clear(mm, vaddr, pmdp);
 206         pmd = READ_ONCE(*pmdp);
 207         WARN_ON(!pmd_none(pmd));
 208
 209         pmd = pfn_pmd(pfn, prot);
 210         pmd = pmd_wrprotect(pmd);
 211         pmd = pmd_mkclean(pmd);
 212         set_pmd_at(mm, vaddr, pmdp, pmd);
 213         pmd = pmd_mkwrite(pmd);
 214         pmd = pmd_mkdirty(pmd);
 215         pmdp_set_access_flags(vma, vaddr, pmdp, pmd, 1);
 216         pmd = READ_ONCE(*pmdp);
 217         WARN_ON(!(pmd_write(pmd) && pmd_dirty(pmd)));
 218         pmdp_huge_get_and_clear_full(vma, vaddr, pmdp, 1);
 219         pmd = READ_ONCE(*pmdp);
 220         WARN_ON(!pmd_none(pmd));
 221
 222         pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
 223         pmd = pmd_mkyoung(pmd);
 224         set_pmd_at(mm, vaddr, pmdp, pmd);
 225         pmdp_test_and_clear_young(vma, vaddr, pmdp);
 226         pmd = READ_ONCE(*pmdp);
 227         WARN_ON(pmd_young(pmd));
 228
 229         /*  Clear the pte entries  */
 230         pmdp_huge_get_and_clear(mm, vaddr, pmdp);
 231         pgtable = pgtable_trans_huge_withdraw(mm, pmdp);
 232 }
 233
 234 static void __init pmd_leaf_tests(unsigned long pfn, pgprot_t prot)
 235 {
 236         pmd_t pmd;
 237
 238         if (!has_transparent_hugepage())
 239                 return;
 240
 241         pr_debug("Validating PMD leaf\n");
 242         pmd = pfn_pmd(pfn, prot);
 243
 244         /*
 245          * PMD based THP is a leaf entry.
 246          */
 247         pmd = pmd_mkhuge(pmd);
 248         WARN_ON(!pmd_leaf(pmd));
 249 }
 250
 251 static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot)
 252 {
 253         pmd_t pmd;
 254
 255         if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
 256                 return;
 257
 258         if (!has_transparent_hugepage())
 259                 return;
 260
 261         pr_debug("Validating PMD saved write\n");
 262         pmd = pfn_pmd(pfn, prot);
 263         WARN_ON(!pmd_savedwrite(pmd_mk_savedwrite(pmd_clear_savedwrite(pmd))));
 264         WARN_ON(pmd_savedwrite(pmd_clear_savedwrite(pmd_mk_savedwrite(pmd))));
 265 }
 266
 267 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
 268 static void __init pud_basic_tests(struct mm_struct *mm, unsigned long pfn, int idx)
 269 {
 270         pgprot_t prot = protection_map[idx];
 271         unsigned long val = idx, *ptr = &val;
 272         pud_t pud;
 273
 274         if (!has_transparent_hugepage())
 275                 return;
 276
 277         pr_debug("Validating PUD basic (%pGv)\n", ptr);
 278         pud = pfn_pud(pfn, prot);
 279
 280         /*
 281          * This test needs to be executed after the given page table entry
 282          * is created with pfn_pud() to make sure that protection_map[idx]
 283          * does not have the dirty bit enabled from the beginning. This is
 284          * important for platforms like arm64 where (!PTE_RDONLY) indicate
 285          * dirty bit being set.
 286          */
 287         WARN_ON(pud_dirty(pud_wrprotect(pud)));
 288
 289         WARN_ON(!pud_same(pud, pud));
 290         WARN_ON(!pud_young(pud_mkyoung(pud_mkold(pud))));
 291         WARN_ON(!pud_dirty(pud_mkdirty(pud_mkclean(pud))));
 292         WARN_ON(pud_dirty(pud_mkclean(pud_mkdirty(pud))));
 293         WARN_ON(!pud_write(pud_mkwrite(pud_wrprotect(pud))));
 294         WARN_ON(pud_write(pud_wrprotect(pud_mkwrite(pud))));
 295         WARN_ON(pud_young(pud_mkold(pud_mkyoung(pud))));
 296         WARN_ON(pud_dirty(pud_wrprotect(pud_mkclean(pud))));
 297         WARN_ON(!pud_dirty(pud_wrprotect(pud_mkdirty(pud))));
 298
 299         if (mm_pmd_folded(mm))
 300                 return;
 301
 302         /*
 303          * A huge page does not point to next level page table
 304          * entry. Hence this must qualify as pud_bad().
 305          */
 306         WARN_ON(!pud_bad(pud_mkhuge(pud)));
 307 }
 308
 309 static void __init pud_advanced_tests(struct mm_struct *mm,
 310                                       struct vm_area_struct *vma, pud_t *pudp,
 311                                       unsigned long pfn, unsigned long vaddr,
 312                                       pgprot_t prot)
 313 {
 314         pud_t pud;
 315
 316         if (!has_transparent_hugepage())
 317                 return;
 318
 319         pr_debug("Validating PUD advanced\n");
 320         /* Align the address wrt HPAGE_PUD_SIZE */
 321         vaddr &= HPAGE_PUD_MASK;
 322
 323         pud = pfn_pud(pfn, prot);
 324         set_pud_at(mm, vaddr, pudp, pud);
 325         pudp_set_wrprotect(mm, vaddr, pudp);
 326         pud = READ_ONCE(*pudp);
 327         WARN_ON(pud_write(pud));
 328
 329 #ifndef __PAGETABLE_PMD_FOLDED
 330         pudp_huge_get_and_clear(mm, vaddr, pudp);
 331         pud = READ_ONCE(*pudp);
 332         WARN_ON(!pud_none(pud));
 333 #endif /* __PAGETABLE_PMD_FOLDED */
 334         pud = pfn_pud(pfn, prot);
 335         pud = pud_wrprotect(pud);
 336         pud = pud_mkclean(pud);
 337         set_pud_at(mm, vaddr, pudp, pud);
 338         pud = pud_mkwrite(pud);
 339         pud = pud_mkdirty(pud);
 340         pudp_set_access_flags(vma, vaddr, pudp, pud, 1);
 341         pud = READ_ONCE(*pudp);
 342         WARN_ON(!(pud_write(pud) && pud_dirty(pud)));
 343
 344 #ifndef __PAGETABLE_PMD_FOLDED
 345         pudp_huge_get_and_clear_full(mm, vaddr, pudp, 1);
 346         pud = READ_ONCE(*pudp);
 347         WARN_ON(!pud_none(pud));
 348 #endif /* __PAGETABLE_PMD_FOLDED */
 349
 350         pud = pfn_pud(pfn, prot);
 351         pud = pud_mkyoung(pud);
 352         set_pud_at(mm, vaddr, pudp, pud);
 353         pudp_test_and_clear_young(vma, vaddr, pudp);
 354         pud = READ_ONCE(*pudp);
 355         WARN_ON(pud_young(pud));
 356
 357         pudp_huge_get_and_clear(mm, vaddr, pudp);
 358 }
 359
 360 static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot)
 361 {
 362         pud_t pud;
 363
 364         if (!has_transparent_hugepage())
 365                 return;
 366
 367         pr_debug("Validating PUD leaf\n");
 368         pud = pfn_pud(pfn, prot);
 369         /*
 370          * PUD based THP is a leaf entry.
 371          */
 372         pud = pud_mkhuge(pud);
 373         WARN_ON(!pud_leaf(pud));
 374 }
 375 #else  /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
 376 static void __init pud_basic_tests(struct mm_struct *mm, unsigned long pfn, int idx) { }
 377 static void __init pud_advanced_tests(struct mm_struct *mm,
 378                                       struct vm_area_struct *vma, pud_t *pudp,
 379                                       unsigned long pfn, unsigned long vaddr,
 380                                       pgprot_t prot)
 381 {
 382 }
 383 static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot) { }
 384 #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
 385 #else  /* !CONFIG_TRANSPARENT_HUGEPAGE */
 386 static void __init pmd_basic_tests(unsigned long pfn, int idx) { }
 387 static void __init pud_basic_tests(struct mm_struct *mm, unsigned long pfn, int idx) { }
 388 static void __init pmd_advanced_tests(struct mm_struct *mm,
 389                                       struct vm_area_struct *vma, pmd_t *pmdp,
 390                                       unsigned long pfn, unsigned long vaddr,
 391                                       pgprot_t prot, pgtable_t pgtable)
 392 {
 393 }
 394 static void __init pud_advanced_tests(struct mm_struct *mm,
 395                                       struct vm_area_struct *vma, pud_t *pudp,
 396                                       unsigned long pfn, unsigned long vaddr,
 397                                       pgprot_t prot)
 398 {
 399 }
 400 static void __init pmd_leaf_tests(unsigned long pfn, pgprot_t prot) { }
 401 static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot) { }
 402 static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot) { }
 403 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 404
 405 #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
 406 static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot)
 407 {
 408         pmd_t pmd;
 409
 410         if (!arch_vmap_pmd_supported(prot))
 411                 return;
 412
 413         pr_debug("Validating PMD huge\n");
 414         /*
 415          * X86 defined pmd_set_huge() verifies that the given
 416          * PMD is not a populated non-leaf entry.
 417          */
 418         WRITE_ONCE(*pmdp, __pmd(0));
 419         WARN_ON(!pmd_set_huge(pmdp, __pfn_to_phys(pfn), prot));
 420         WARN_ON(!pmd_clear_huge(pmdp));
 421         pmd = READ_ONCE(*pmdp);
 422         WARN_ON(!pmd_none(pmd));
 423 }
 424
 425 static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot)
 426 {
 427         pud_t pud;
 428
 429         if (!arch_vmap_pud_supported(prot))
 430                 return;
 431
 432         pr_debug("Validating PUD huge\n");
 433         /*
 434          * X86 defined pud_set_huge() verifies that the given
 435          * PUD is not a populated non-leaf entry.
 436          */
 437         WRITE_ONCE(*pudp, __pud(0));
 438         WARN_ON(!pud_set_huge(pudp, __pfn_to_phys(pfn), prot));
 439         WARN_ON(!pud_clear_huge(pudp));
 440         pud = READ_ONCE(*pudp);
 441         WARN_ON(!pud_none(pud));
 442 }
 443 #else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
 444 static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot) { }
 445 static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot) { }
 446 #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
 447
 448 static void __init p4d_basic_tests(unsigned long pfn, pgprot_t prot)
 449 {
 450         p4d_t p4d;
 451
 452         pr_debug("Validating P4D basic\n");
 453         memset(&p4d, RANDOM_NZVALUE, sizeof(p4d_t));
 454         WARN_ON(!p4d_same(p4d, p4d));
 455 }
 456
 457 static void __init pgd_basic_tests(unsigned long pfn, pgprot_t prot)
 458 {
 459         pgd_t pgd;
 460
 461         pr_debug("Validating PGD basic\n");
 462         memset(&pgd, RANDOM_NZVALUE, sizeof(pgd_t));
 463         WARN_ON(!pgd_same(pgd, pgd));
 464 }
 465
 466 #ifndef __PAGETABLE_PUD_FOLDED
 467 static void __init pud_clear_tests(struct mm_struct *mm, pud_t *pudp)
 468 {
 469         pud_t pud = READ_ONCE(*pudp);
 470
 471         if (mm_pmd_folded(mm))
 472                 return;
 473
 474         pr_debug("Validating PUD clear\n");
 475         pud = __pud(pud_val(pud) | RANDOM_ORVALUE);
 476         WRITE_ONCE(*pudp, pud);
 477         pud_clear(pudp);
 478         pud = READ_ONCE(*pudp);
 479         WARN_ON(!pud_none(pud));
 480 }
 481
 482 static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp,
 483                                       pmd_t *pmdp)
 484 {
 485         pud_t pud;
 486
 487         if (mm_pmd_folded(mm))
 488                 return;
 489
 490         pr_debug("Validating PUD populate\n");
 491         /*
 492          * This entry points to next level page table page.
 493          * Hence this must not qualify as pud_bad().
 494          */
 495         pud_populate(mm, pudp, pmdp);
 496         pud = READ_ONCE(*pudp);
 497         WARN_ON(pud_bad(pud));
 498 }
 499 #else  /* !__PAGETABLE_PUD_FOLDED */
 500 static void __init pud_clear_tests(struct mm_struct *mm, pud_t *pudp) { }
 501 static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp,
 502                                       pmd_t *pmdp)
 503 {
 504 }
 505 #endif /* PAGETABLE_PUD_FOLDED */
 506
 507 #ifndef __PAGETABLE_P4D_FOLDED
 508 static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp)
 509 {
 510         p4d_t p4d = READ_ONCE(*p4dp);
 511
 512         if (mm_pud_folded(mm))
 513                 return;
 514
 515         pr_debug("Validating P4D clear\n");
 516         p4d = __p4d(p4d_val(p4d) | RANDOM_ORVALUE);
 517         WRITE_ONCE(*p4dp, p4d);
 518         p4d_clear(p4dp);
 519         p4d = READ_ONCE(*p4dp);
 520         WARN_ON(!p4d_none(p4d));
 521 }
 522
 523 static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp,
 524                                       pud_t *pudp)
 525 {
 526         p4d_t p4d;
 527
 528         if (mm_pud_folded(mm))
 529                 return;
 530
 531         pr_debug("Validating P4D populate\n");
 532         /*
 533          * This entry points to next level page table page.
 534          * Hence this must not qualify as p4d_bad().
 535          */
 536         pud_clear(pudp);
 537         p4d_clear(p4dp);
 538         p4d_populate(mm, p4dp, pudp);
 539         p4d = READ_ONCE(*p4dp);
 540         WARN_ON(p4d_bad(p4d));
 541 }
 542
 543 static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp)
 544 {
 545         pgd_t pgd = READ_ONCE(*pgdp);
 546
 547         if (mm_p4d_folded(mm))
 548                 return;
 549
 550         pr_debug("Validating PGD clear\n");
 551         pgd = __pgd(pgd_val(pgd) | RANDOM_ORVALUE);
 552         WRITE_ONCE(*pgdp, pgd);
 553         pgd_clear(pgdp);
 554         pgd = READ_ONCE(*pgdp);
 555         WARN_ON(!pgd_none(pgd));
 556 }
 557
 558 static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
 559                                       p4d_t *p4dp)
 560 {
 561         pgd_t pgd;
 562
 563         if (mm_p4d_folded(mm))
 564                 return;
 565
 566         pr_debug("Validating PGD populate\n");
 567         /*
 568          * This entry points to next level page table page.
 569          * Hence this must not qualify as pgd_bad().
 570          */
 571         p4d_clear(p4dp);
 572         pgd_clear(pgdp);
 573         pgd_populate(mm, pgdp, p4dp);
 574         pgd = READ_ONCE(*pgdp);
 575         WARN_ON(pgd_bad(pgd));
 576 }
 577 #else  /* !__PAGETABLE_P4D_FOLDED */
 578 static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp) { }
 579 static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp) { }
 580 static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp,
 581                                       pud_t *pudp)
 582 {
 583 }
 584 static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
 585                                       p4d_t *p4dp)
 586 {
 587 }
 588 #endif /* PAGETABLE_P4D_FOLDED */
 589
 590 static void __init pte_clear_tests(struct mm_struct *mm, pte_t *ptep,
 591                                    unsigned long pfn, unsigned long vaddr,
 592                                    pgprot_t prot)
 593 {
 594         pte_t pte = pfn_pte(pfn, prot);
 595
 596         pr_debug("Validating PTE clear\n");
 597 #ifndef CONFIG_RISCV
 598         pte = __pte(pte_val(pte) | RANDOM_ORVALUE);
 599 #endif
 600         set_pte_at(mm, vaddr, ptep, pte);
 601         barrier();
 602         pte_clear(mm, vaddr, ptep);
 603         pte = ptep_get(ptep);
 604         WARN_ON(!pte_none(pte));
 605 }
 606
 607 static void __init pmd_clear_tests(struct mm_struct *mm, pmd_t *pmdp)
 608 {
 609         pmd_t pmd = READ_ONCE(*pmdp);
 610
 611         pr_debug("Validating PMD clear\n");
 612         pmd = __pmd(pmd_val(pmd) | RANDOM_ORVALUE);
 613         WRITE_ONCE(*pmdp, pmd);
 614         pmd_clear(pmdp);
 615         pmd = READ_ONCE(*pmdp);
 616         WARN_ON(!pmd_none(pmd));
 617 }
 618
 619 static void __init pmd_populate_tests(struct mm_struct *mm, pmd_t *pmdp,
 620                                       pgtable_t pgtable)
 621 {
 622         pmd_t pmd;
 623
 624         pr_debug("Validating PMD populate\n");
 625         /*
 626          * This entry points to next level page table page.
 627          * Hence this must not qualify as pmd_bad().
 628          */
 629         pmd_populate(mm, pmdp, pgtable);
 630         pmd = READ_ONCE(*pmdp);
 631         WARN_ON(pmd_bad(pmd));
 632 }
 633
 634 static void __init pte_special_tests(unsigned long pfn, pgprot_t prot)
 635 {
 636         pte_t pte = pfn_pte(pfn, prot);
 637
 638         if (!IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL))
 639                 return;
 640
 641         pr_debug("Validating PTE special\n");
 642         WARN_ON(!pte_special(pte_mkspecial(pte)));
 643 }
 644
 645 static void __init pte_protnone_tests(unsigned long pfn, pgprot_t prot)
 646 {
 647         pte_t pte = pfn_pte(pfn, prot);
 648
 649         if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
 650                 return;
 651
 652         pr_debug("Validating PTE protnone\n");
 653         WARN_ON(!pte_protnone(pte));
 654         WARN_ON(!pte_present(pte));
 655 }
 656
 657 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 658 static void __init pmd_protnone_tests(unsigned long pfn, pgprot_t prot)
 659 {
 660         pmd_t pmd;
 661
 662         if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
 663                 return;
 664
 665         if (!has_transparent_hugepage())
 666                 return;
 667
 668         pr_debug("Validating PMD protnone\n");
 669         pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
 670         WARN_ON(!pmd_protnone(pmd));
 671         WARN_ON(!pmd_present(pmd));
 672 }
 673 #else  /* !CONFIG_TRANSPARENT_HUGEPAGE */
 674 static void __init pmd_protnone_tests(unsigned long pfn, pgprot_t prot) { }
 675 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 676
 677 #ifdef CONFIG_ARCH_HAS_PTE_DEVMAP
 678 static void __init pte_devmap_tests(unsigned long pfn, pgprot_t prot)
 679 {
 680         pte_t pte = pfn_pte(pfn, prot);
 681
 682         pr_debug("Validating PTE devmap\n");
 683         WARN_ON(!pte_devmap(pte_mkdevmap(pte)));
 684 }
 685
 686 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 687 static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot)
 688 {
 689         pmd_t pmd;
 690
 691         if (!has_transparent_hugepage())
 692                 return;
 693
 694         pr_debug("Validating PMD devmap\n");
 695         pmd = pfn_pmd(pfn, prot);
 696         WARN_ON(!pmd_devmap(pmd_mkdevmap(pmd)));
 697 }
 698
 699 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
 700 static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot)
 701 {
 702         pud_t pud;
 703
 704         if (!has_transparent_hugepage())
 705                 return;
 706
 707         pr_debug("Validating PUD devmap\n");
 708         pud = pfn_pud(pfn, prot);
 709         WARN_ON(!pud_devmap(pud_mkdevmap(pud)));
 710 }
 711 #else  /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
 712 static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) { }
 713 #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
 714 #else  /* CONFIG_TRANSPARENT_HUGEPAGE */
 715 static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot) { }
 716 static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) { }
 717 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 718 #else
 719 static void __init pte_devmap_tests(unsigned long pfn, pgprot_t prot) { }
 720 static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot) { }
 721 static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) { }
 722 #endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */
 723
 724 static void __init pte_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
 725 {
 726         pte_t pte = pfn_pte(pfn, prot);
 727
 728         if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
 729                 return;
 730
 731         pr_debug("Validating PTE soft dirty\n");
 732         WARN_ON(!pte_soft_dirty(pte_mksoft_dirty(pte)));
 733         WARN_ON(pte_soft_dirty(pte_clear_soft_dirty(pte)));
 734 }
 735
 736 static void __init pte_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
 737 {
 738         pte_t pte = pfn_pte(pfn, prot);
 739
 740         if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
 741                 return;
 742
 743         pr_debug("Validating PTE swap soft dirty\n");
 744         WARN_ON(!pte_swp_soft_dirty(pte_swp_mksoft_dirty(pte)));
 745         WARN_ON(pte_swp_soft_dirty(pte_swp_clear_soft_dirty(pte)));
 746 }
 747
 748 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 749 static void __init pmd_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
 750 {
 751         pmd_t pmd;
 752
 753         if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
 754                 return;
 755
 756         if (!has_transparent_hugepage())
 757                 return;
 758
 759         pr_debug("Validating PMD soft dirty\n");
 760         pmd = pfn_pmd(pfn, prot);
 761         WARN_ON(!pmd_soft_dirty(pmd_mksoft_dirty(pmd)));
 762         WARN_ON(pmd_soft_dirty(pmd_clear_soft_dirty(pmd)));
 763 }
 764
 765 static void __init pmd_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
 766 {
 767         pmd_t pmd;
 768
 769         if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY) ||
 770                 !IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION))
 771                 return;
 772
 773         if (!has_transparent_hugepage())
 774                 return;
 775
 776         pr_debug("Validating PMD swap soft dirty\n");
 777         pmd = pfn_pmd(pfn, prot);
 778         WARN_ON(!pmd_swp_soft_dirty(pmd_swp_mksoft_dirty(pmd)));
 779         WARN_ON(pmd_swp_soft_dirty(pmd_swp_clear_soft_dirty(pmd)));
 780 }
 781 #else  /* !CONFIG_TRANSPARENT_HUGEPAGE */
 782 static void __init pmd_soft_dirty_tests(unsigned long pfn, pgprot_t prot) { }
 783 static void __init pmd_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
 784 {
 785 }
 786 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 787
 788 static void __init pte_swap_tests(unsigned long pfn, pgprot_t prot)
 789 {
 790         swp_entry_t swp;
 791         pte_t pte;
 792
 793         pr_debug("Validating PTE swap\n");
 794         pte = pfn_pte(pfn, prot);
 795         swp = __pte_to_swp_entry(pte);
 796         pte = __swp_entry_to_pte(swp);
 797         WARN_ON(pfn != pte_pfn(pte));
 798 }
 799
 800 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
 801 static void __init pmd_swap_tests(unsigned long pfn, pgprot_t prot)
 802 {
 803         swp_entry_t swp;
 804         pmd_t pmd;
 805
 806         if (!has_transparent_hugepage())
 807                 return;
 808
 809         pr_debug("Validating PMD swap\n");
 810         pmd = pfn_pmd(pfn, prot);
 811         swp = __pmd_to_swp_entry(pmd);
 812         pmd = __swp_entry_to_pmd(swp);
 813         WARN_ON(pfn != pmd_pfn(pmd));
 814 }
 815 #else  /* !CONFIG_ARCH_ENABLE_THP_MIGRATION */
 816 static void __init pmd_swap_tests(unsigned long pfn, pgprot_t prot) { }
 817 #endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
 818
 819 static void __init swap_migration_tests(void)
 820 {
 821         struct page *page;
 822         swp_entry_t swp;
 823
 824         if (!IS_ENABLED(CONFIG_MIGRATION))
 825                 return;
 826
 827         pr_debug("Validating swap migration\n");
 828         /*
 829          * swap_migration_tests() requires a dedicated page as it needs to
 830          * be locked before creating a migration entry from it. Locking the
 831          * page that actually maps kernel text ('start_kernel') can be real
 832          * problematic. Lets allocate a dedicated page explicitly for this
 833          * purpose that will be freed subsequently.
 834          */
 835         page = alloc_page(GFP_KERNEL);
 836         if (!page) {
 837                 pr_err("page allocation failed\n");
 838                 return;
 839         }
 840
 841         /*
 842          * make_migration_entry() expects given page to be
 843          * locked, otherwise it stumbles upon a BUG_ON().
 844          */
 845         __SetPageLocked(page);
 846         swp = make_writable_migration_entry(page_to_pfn(page));
 847         WARN_ON(!is_migration_entry(swp));
 848         WARN_ON(!is_writable_migration_entry(swp));
 849
 850         swp = make_readable_migration_entry(swp_offset(swp));
 851         WARN_ON(!is_migration_entry(swp));
 852         WARN_ON(is_writable_migration_entry(swp));
 853
 854         swp = make_readable_migration_entry(page_to_pfn(page));
 855         WARN_ON(!is_migration_entry(swp));
 856         WARN_ON(is_writable_migration_entry(swp));
 857         __ClearPageLocked(page);
 858         __free_page(page);
 859 }
 860
 861 #ifdef CONFIG_HUGETLB_PAGE
 862 static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot)
 863 {
 864         struct page *page;
 865         pte_t pte;
 866
 867         pr_debug("Validating HugeTLB basic\n");
 868         /*
 869          * Accessing the page associated with the pfn is safe here,
 870          * as it was previously derived from a real kernel symbol.
 871          */
 872         page = pfn_to_page(pfn);
 873         pte = mk_huge_pte(page, prot);
 874
 875         WARN_ON(!huge_pte_dirty(huge_pte_mkdirty(pte)));
 876         WARN_ON(!huge_pte_write(huge_pte_mkwrite(huge_pte_wrprotect(pte))));
 877         WARN_ON(huge_pte_write(huge_pte_wrprotect(huge_pte_mkwrite(pte))));
 878
 879 #ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB
 880         pte = pfn_pte(pfn, prot);
 881
 882         WARN_ON(!pte_huge(pte_mkhuge(pte)));
 883 #endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */
 884 }
 885 #else  /* !CONFIG_HUGETLB_PAGE */
 886 static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot) { }
 887 #endif /* CONFIG_HUGETLB_PAGE */
 888
 889 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 890 static void __init pmd_thp_tests(unsigned long pfn, pgprot_t prot)
 891 {
 892         pmd_t pmd;
 893
 894         if (!has_transparent_hugepage())
 895                 return;
 896
 897         pr_debug("Validating PMD based THP\n");
 898         /*
 899          * pmd_trans_huge() and pmd_present() must return positive after
 900          * MMU invalidation with pmd_mkinvalid(). This behavior is an
 901          * optimization for transparent huge page. pmd_trans_huge() must
 902          * be true if pmd_page() returns a valid THP to avoid taking the
 903          * pmd_lock when others walk over non transhuge pmds (i.e. there
 904          * are no THP allocated). Especially when splitting a THP and
 905          * removing the present bit from the pmd, pmd_trans_huge() still
 906          * needs to return true. pmd_present() should be true whenever
 907          * pmd_trans_huge() returns true.
 908          */
 909         pmd = pfn_pmd(pfn, prot);
 910         WARN_ON(!pmd_trans_huge(pmd_mkhuge(pmd)));
 911
 912 #ifndef __HAVE_ARCH_PMDP_INVALIDATE
 913         WARN_ON(!pmd_trans_huge(pmd_mkinvalid(pmd_mkhuge(pmd))));
 914         WARN_ON(!pmd_present(pmd_mkinvalid(pmd_mkhuge(pmd))));
 915 #endif /* __HAVE_ARCH_PMDP_INVALIDATE */
 916 }
 917
 918 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
 919 static void __init pud_thp_tests(unsigned long pfn, pgprot_t prot)
 920 {
 921         pud_t pud;
 922
 923         if (!has_transparent_hugepage())
 924                 return;
 925
 926         pr_debug("Validating PUD based THP\n");
 927         pud = pfn_pud(pfn, prot);
 928         WARN_ON(!pud_trans_huge(pud_mkhuge(pud)));
 929
 930         /*
 931          * pud_mkinvalid() has been dropped for now. Enable back
 932          * these tests when it comes back with a modified pud_present().
 933          *
 934          * WARN_ON(!pud_trans_huge(pud_mkinvalid(pud_mkhuge(pud))));
 935          * WARN_ON(!pud_present(pud_mkinvalid(pud_mkhuge(pud))));
 936          */
 937 }
 938 #else  /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
 939 static void __init pud_thp_tests(unsigned long pfn, pgprot_t prot) { }
 940 #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
 941 #else  /* !CONFIG_TRANSPARENT_HUGEPAGE */
 942 static void __init pmd_thp_tests(unsigned long pfn, pgprot_t prot) { }
 943 static void __init pud_thp_tests(unsigned long pfn, pgprot_t prot) { }
 944 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 945
 946 static unsigned long __init get_random_vaddr(void)
 947 {
 948         unsigned long random_vaddr, random_pages, total_user_pages;
 949
 950         total_user_pages = (TASK_SIZE - FIRST_USER_ADDRESS) / PAGE_SIZE;
 951
 952         random_pages = get_random_long() % total_user_pages;
 953         random_vaddr = FIRST_USER_ADDRESS + random_pages * PAGE_SIZE;
 954
 955         return random_vaddr;
 956 }
 957
 958 static int __init debug_vm_pgtable(void)
 959 {
 960         struct vm_area_struct *vma;
 961         struct mm_struct *mm;
 962         pgd_t *pgdp;
 963         p4d_t *p4dp, *saved_p4dp;
 964         pud_t *pudp, *saved_pudp;
 965         pmd_t *pmdp, *saved_pmdp, pmd;
 966         pte_t *ptep;
 967         pgtable_t saved_ptep;
 968         pgprot_t prot, protnone;
 969         phys_addr_t paddr;
 970         unsigned long vaddr, pte_aligned, pmd_aligned;
 971         unsigned long pud_aligned, p4d_aligned, pgd_aligned;
 972         spinlock_t *ptl = NULL;
 973         int idx;
 974
 975         pr_info("Validating architecture page table helpers\n");
 976         prot = vm_get_page_prot(VMFLAGS);
 977         vaddr = get_random_vaddr();
 978         mm = mm_alloc();
 979         if (!mm) {
 980                 pr_err("mm_struct allocation failed\n");
 981                 return 1;
 982         }
 983
 984         /*
 985          * __P000 (or even __S000) will help create page table entries with
 986          * PROT_NONE permission as required for pxx_protnone_tests().
 987          */
 988         protnone = __P000;
 989
 990         vma = vm_area_alloc(mm);
 991         if (!vma) {
 992                 pr_err("vma allocation failed\n");
 993                 return 1;
 994         }
 995
 996         /*
 997          * PFN for mapping at PTE level is determined from a standard kernel
 998          * text symbol. But pfns for higher page table levels are derived by
 999          * masking lower bits of this real pfn. These derived pfns might not
1000          * exist on the platform but that does not really matter as pfn_pxx()
1001          * helpers will still create appropriate entries for the test. This
1002          * helps avoid large memory block allocations to be used for mapping
1003          * at higher page table levels.
1004          */
1005         paddr = __pa_symbol(&start_kernel);
1006
1007         pte_aligned = (paddr & PAGE_MASK) >> PAGE_SHIFT;
1008         pmd_aligned = (paddr & PMD_MASK) >> PAGE_SHIFT;
1009         pud_aligned = (paddr & PUD_MASK) >> PAGE_SHIFT;
1010         p4d_aligned = (paddr & P4D_MASK) >> PAGE_SHIFT;
1011         pgd_aligned = (paddr & PGDIR_MASK) >> PAGE_SHIFT;
1012         WARN_ON(!pfn_valid(pte_aligned));
1013
1014         pgdp = pgd_offset(mm, vaddr);
1015         p4dp = p4d_alloc(mm, pgdp, vaddr);
1016         pudp = pud_alloc(mm, p4dp, vaddr);
1017         pmdp = pmd_alloc(mm, pudp, vaddr);
1018         /*
1019          * Allocate pgtable_t
1020          */
1021         if (pte_alloc(mm, pmdp)) {
1022                 pr_err("pgtable allocation failed\n");
1023                 return 1;
1024         }
1025
1026         /*
1027          * Save all the page table page addresses as the page table
1028          * entries will be used for testing with random or garbage
1029          * values. These saved addresses will be used for freeing
1030          * page table pages.
1031          */
1032         pmd = READ_ONCE(*pmdp);
1033         saved_p4dp = p4d_offset(pgdp, 0UL);
1034         saved_pudp = pud_offset(p4dp, 0UL);
1035         saved_pmdp = pmd_offset(pudp, 0UL);
1036         saved_ptep = pmd_pgtable(pmd);
1037
1038         /*
1039          * Iterate over the protection_map[] to make sure that all
1040          * the basic page table transformation validations just hold
1041          * true irrespective of the starting protection value for a
1042          * given page table entry.
1043          */
1044         for (idx = 0; idx < ARRAY_SIZE(protection_map); idx++) {
1045                 pte_basic_tests(pte_aligned, idx);
1046                 pmd_basic_tests(pmd_aligned, idx);
1047                 pud_basic_tests(mm, pud_aligned, idx);
1048         }
1049
1050         /*
1051          * Both P4D and PGD level tests are very basic which do not
1052          * involve creating page table entries from the protection
1053          * value and the given pfn. Hence just keep them out from
1054          * the above iteration for now to save some test execution
1055          * time.
1056          */
1057         p4d_basic_tests(p4d_aligned, prot);
1058         pgd_basic_tests(pgd_aligned, prot);
1059
1060         pmd_leaf_tests(pmd_aligned, prot);
1061         pud_leaf_tests(pud_aligned, prot);
1062
1063         pte_savedwrite_tests(pte_aligned, protnone);
1064         pmd_savedwrite_tests(pmd_aligned, protnone);
1065
1066         pte_special_tests(pte_aligned, prot);
1067         pte_protnone_tests(pte_aligned, protnone);
1068         pmd_protnone_tests(pmd_aligned, protnone);
1069
1070         pte_devmap_tests(pte_aligned, prot);
1071         pmd_devmap_tests(pmd_aligned, prot);
1072         pud_devmap_tests(pud_aligned, prot);
1073
1074         pte_soft_dirty_tests(pte_aligned, prot);
1075         pmd_soft_dirty_tests(pmd_aligned, prot);
1076         pte_swap_soft_dirty_tests(pte_aligned, prot);
1077         pmd_swap_soft_dirty_tests(pmd_aligned, prot);
1078
1079         pte_swap_tests(pte_aligned, prot);
1080         pmd_swap_tests(pmd_aligned, prot);
1081
1082         swap_migration_tests();
1083
1084         pmd_thp_tests(pmd_aligned, prot);
1085         pud_thp_tests(pud_aligned, prot);
1086
1087         hugetlb_basic_tests(pte_aligned, prot);
1088
1089         /*
1090          * Page table modifying tests. They need to hold
1091          * proper page table lock.
1092          */
1093
1094         ptep = pte_offset_map_lock(mm, pmdp, vaddr, &ptl);
1095         pte_clear_tests(mm, ptep, pte_aligned, vaddr, prot);
1096         pte_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot);
1097         pte_unmap_unlock(ptep, ptl);
1098
1099         ptl = pmd_lock(mm, pmdp);
1100         pmd_clear_tests(mm, pmdp);
1101         pmd_advanced_tests(mm, vma, pmdp, pmd_aligned, vaddr, prot, saved_ptep);
1102         pmd_huge_tests(pmdp, pmd_aligned, prot);
1103         pmd_populate_tests(mm, pmdp, saved_ptep);
1104         spin_unlock(ptl);
1105
1106         ptl = pud_lock(mm, pudp);
1107         pud_clear_tests(mm, pudp);
1108         pud_advanced_tests(mm, vma, pudp, pud_aligned, vaddr, prot);
1109         pud_huge_tests(pudp, pud_aligned, prot);
1110         pud_populate_tests(mm, pudp, saved_pmdp);
1111         spin_unlock(ptl);
1112
1113         spin_lock(&mm->page_table_lock);
1114         p4d_clear_tests(mm, p4dp);
1115         pgd_clear_tests(mm, pgdp);
1116         p4d_populate_tests(mm, p4dp, saved_pudp);
1117         pgd_populate_tests(mm, pgdp, saved_p4dp);
1118         spin_unlock(&mm->page_table_lock);
1119
1120         p4d_free(mm, saved_p4dp);
1121         pud_free(mm, saved_pudp);
1122         pmd_free(mm, saved_pmdp);
1123         pte_free(mm, saved_ptep);
1124
1125         vm_area_free(vma);
1126         mm_dec_nr_puds(mm);
1127         mm_dec_nr_pmds(mm);
1128         mm_dec_nr_ptes(mm);
1129         mmdrop(mm);
1130         return 0;
1131 }
1132 late_initcall(debug_vm_pgtable);