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
  33 #include <asm/cacheflush.h>
  34 #include <asm/pgalloc.h>
  35 #include <asm/tlbflush.h>
  36
  37 /*
  38  * Please refer Documentation/vm/arch_pgtable_helpers.rst for the semantics
  39  * expectations that are being validated here. All future changes in here
  40  * or the documentation need to be in sync.
  41  */
  42
  43 #define VMFLAGS (VM_READ|VM_WRITE|VM_EXEC)
  44
  45 /*
  46  * On s390 platform, the lower 4 bits are used to identify given page table
  47  * entry type. But these bits might affect the ability to clear entries with
  48  * pxx_clear() because of how dynamic page table folding works on s390. So
  49  * while loading up the entries do not change the lower 4 bits. It does not
  50  * have affect any other platform. Also avoid the 62nd bit on ppc64 that is
  51  * used to mark a pte entry.
  52  */
  53 #define S390_SKIP_MASK          GENMASK(3, 0)
  54 #if __BITS_PER_LONG == 64
  55 #define PPC64_SKIP_MASK         GENMASK(62, 62)
  56 #else
  57 #define PPC64_SKIP_MASK         0x0
  58 #endif
  59 #define ARCH_SKIP_MASK (S390_SKIP_MASK | PPC64_SKIP_MASK)
  60 #define RANDOM_ORVALUE (GENMASK(BITS_PER_LONG - 1, 0) & ~ARCH_SKIP_MASK)
  61 #define RANDOM_NZVALUE  GENMASK(7, 0)
  62
  63 struct pgtable_debug_args {
  64         struct mm_struct        *mm;
  65         struct vm_area_struct   *vma;
  66
  67         pgd_t                   *pgdp;
  68         p4d_t                   *p4dp;
  69         pud_t                   *pudp;
  70         pmd_t                   *pmdp;
  71         pte_t                   *ptep;
  72
  73         p4d_t                   *start_p4dp;
  74         pud_t                   *start_pudp;
  75         pmd_t                   *start_pmdp;
  76         pgtable_t               start_ptep;
  77
  78         unsigned long           vaddr;
  79         pgprot_t                page_prot;
  80         pgprot_t                page_prot_none;
  81
  82         bool                    is_contiguous_page;
  83         unsigned long           pud_pfn;
  84         unsigned long           pmd_pfn;
  85         unsigned long           pte_pfn;
  86
  87         unsigned long           fixed_pgd_pfn;
  88         unsigned long           fixed_p4d_pfn;
  89         unsigned long           fixed_pud_pfn;
  90         unsigned long           fixed_pmd_pfn;
  91         unsigned long           fixed_pte_pfn;
  92 };
  93
  94 static void __init pte_basic_tests(struct pgtable_debug_args *args, int idx)
  95 {
  96         pgprot_t prot = protection_map[idx];
  97         pte_t pte = pfn_pte(args->fixed_pte_pfn, prot);
  98         unsigned long val = idx, *ptr = &val;
  99
 100         pr_debug("Validating PTE basic (%pGv)\n", ptr);
 101
 102         /*
 103          * This test needs to be executed after the given page table entry
 104          * is created with pfn_pte() to make sure that protection_map[idx]
 105          * does not have the dirty bit enabled from the beginning. This is
 106          * important for platforms like arm64 where (!PTE_RDONLY) indicate
 107          * dirty bit being set.
 108          */
 109         WARN_ON(pte_dirty(pte_wrprotect(pte)));
 110
 111         WARN_ON(!pte_same(pte, pte));
 112         WARN_ON(!pte_young(pte_mkyoung(pte_mkold(pte))));
 113         WARN_ON(!pte_dirty(pte_mkdirty(pte_mkclean(pte))));
 114         WARN_ON(!pte_write(pte_mkwrite(pte_wrprotect(pte))));
 115         WARN_ON(pte_young(pte_mkold(pte_mkyoung(pte))));
 116         WARN_ON(pte_dirty(pte_mkclean(pte_mkdirty(pte))));
 117         WARN_ON(pte_write(pte_wrprotect(pte_mkwrite(pte))));
 118         WARN_ON(pte_dirty(pte_wrprotect(pte_mkclean(pte))));
 119         WARN_ON(!pte_dirty(pte_wrprotect(pte_mkdirty(pte))));
 120 }
 121
 122 static void __init pte_advanced_tests(struct pgtable_debug_args *args)
 123 {
 124         struct page *page;
 125         pte_t pte;
 126
 127         /*
 128          * Architectures optimize set_pte_at by avoiding TLB flush.
 129          * This requires set_pte_at to be not used to update an
 130          * existing pte entry. Clear pte before we do set_pte_at
 131          *
 132          * flush_dcache_page() is called after set_pte_at() to clear
 133          * PG_arch_1 for the page on ARM64. The page flag isn't cleared
 134          * when it's released and page allocation check will fail when
 135          * the page is allocated again. For architectures other than ARM64,
 136          * the unexpected overhead of cache flushing is acceptable.
 137          */
 138         page = (args->pte_pfn != ULONG_MAX) ? pfn_to_page(args->pte_pfn) : NULL;
 139         if (!page)
 140                 return;
 141
 142         pr_debug("Validating PTE advanced\n");
 143         pte = pfn_pte(args->pte_pfn, args->page_prot);
 144         set_pte_at(args->mm, args->vaddr, args->ptep, pte);
 145         flush_dcache_page(page);
 146         ptep_set_wrprotect(args->mm, args->vaddr, args->ptep);
 147         pte = ptep_get(args->ptep);
 148         WARN_ON(pte_write(pte));
 149         ptep_get_and_clear(args->mm, args->vaddr, args->ptep);
 150         pte = ptep_get(args->ptep);
 151         WARN_ON(!pte_none(pte));
 152
 153         pte = pfn_pte(args->pte_pfn, args->page_prot);
 154         pte = pte_wrprotect(pte);
 155         pte = pte_mkclean(pte);
 156         set_pte_at(args->mm, args->vaddr, args->ptep, pte);
 157         flush_dcache_page(page);
 158         pte = pte_mkwrite(pte);
 159         pte = pte_mkdirty(pte);
 160         ptep_set_access_flags(args->vma, args->vaddr, args->ptep, pte, 1);
 161         pte = ptep_get(args->ptep);
 162         WARN_ON(!(pte_write(pte) && pte_dirty(pte)));
 163         ptep_get_and_clear_full(args->mm, args->vaddr, args->ptep, 1);
 164         pte = ptep_get(args->ptep);
 165         WARN_ON(!pte_none(pte));
 166
 167         pte = pfn_pte(args->pte_pfn, args->page_prot);
 168         pte = pte_mkyoung(pte);
 169         set_pte_at(args->mm, args->vaddr, args->ptep, pte);
 170         flush_dcache_page(page);
 171         ptep_test_and_clear_young(args->vma, args->vaddr, args->ptep);
 172         pte = ptep_get(args->ptep);
 173         WARN_ON(pte_young(pte));
 174
 175         ptep_get_and_clear_full(args->mm, args->vaddr, args->ptep, 1);
 176 }
 177
 178 static void __init pte_savedwrite_tests(struct pgtable_debug_args *args)
 179 {
 180         pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot_none);
 181
 182         if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
 183                 return;
 184
 185         pr_debug("Validating PTE saved write\n");
 186         WARN_ON(!pte_savedwrite(pte_mk_savedwrite(pte_clear_savedwrite(pte))));
 187         WARN_ON(pte_savedwrite(pte_clear_savedwrite(pte_mk_savedwrite(pte))));
 188 }
 189
 190 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 191 static void __init pmd_basic_tests(struct pgtable_debug_args *args, int idx)
 192 {
 193         pgprot_t prot = protection_map[idx];
 194         unsigned long val = idx, *ptr = &val;
 195         pmd_t pmd;
 196
 197         if (!has_transparent_hugepage())
 198                 return;
 199
 200         pr_debug("Validating PMD basic (%pGv)\n", ptr);
 201         pmd = pfn_pmd(args->fixed_pmd_pfn, prot);
 202
 203         /*
 204          * This test needs to be executed after the given page table entry
 205          * is created with pfn_pmd() to make sure that protection_map[idx]
 206          * does not have the dirty bit enabled from the beginning. This is
 207          * important for platforms like arm64 where (!PTE_RDONLY) indicate
 208          * dirty bit being set.
 209          */
 210         WARN_ON(pmd_dirty(pmd_wrprotect(pmd)));
 211
 212
 213         WARN_ON(!pmd_same(pmd, pmd));
 214         WARN_ON(!pmd_young(pmd_mkyoung(pmd_mkold(pmd))));
 215         WARN_ON(!pmd_dirty(pmd_mkdirty(pmd_mkclean(pmd))));
 216         WARN_ON(!pmd_write(pmd_mkwrite(pmd_wrprotect(pmd))));
 217         WARN_ON(pmd_young(pmd_mkold(pmd_mkyoung(pmd))));
 218         WARN_ON(pmd_dirty(pmd_mkclean(pmd_mkdirty(pmd))));
 219         WARN_ON(pmd_write(pmd_wrprotect(pmd_mkwrite(pmd))));
 220         WARN_ON(pmd_dirty(pmd_wrprotect(pmd_mkclean(pmd))));
 221         WARN_ON(!pmd_dirty(pmd_wrprotect(pmd_mkdirty(pmd))));
 222         /*
 223          * A huge page does not point to next level page table
 224          * entry. Hence this must qualify as pmd_bad().
 225          */
 226         WARN_ON(!pmd_bad(pmd_mkhuge(pmd)));
 227 }
 228
 229 static void __init pmd_advanced_tests(struct pgtable_debug_args *args)
 230 {
 231         struct page *page;
 232         pmd_t pmd;
 233         unsigned long vaddr = args->vaddr;
 234
 235         if (!has_transparent_hugepage())
 236                 return;
 237
 238         page = (args->pmd_pfn != ULONG_MAX) ? pfn_to_page(args->pmd_pfn) : NULL;
 239         if (!page)
 240                 return;
 241
 242         /*
 243          * flush_dcache_page() is called after set_pmd_at() to clear
 244          * PG_arch_1 for the page on ARM64. The page flag isn't cleared
 245          * when it's released and page allocation check will fail when
 246          * the page is allocated again. For architectures other than ARM64,
 247          * the unexpected overhead of cache flushing is acceptable.
 248          */
 249         pr_debug("Validating PMD advanced\n");
 250         /* Align the address wrt HPAGE_PMD_SIZE */
 251         vaddr &= HPAGE_PMD_MASK;
 252
 253         pgtable_trans_huge_deposit(args->mm, args->pmdp, args->start_ptep);
 254
 255         pmd = pfn_pmd(args->pmd_pfn, args->page_prot);
 256         set_pmd_at(args->mm, vaddr, args->pmdp, pmd);
 257         flush_dcache_page(page);
 258         pmdp_set_wrprotect(args->mm, vaddr, args->pmdp);
 259         pmd = READ_ONCE(*args->pmdp);
 260         WARN_ON(pmd_write(pmd));
 261         pmdp_huge_get_and_clear(args->mm, vaddr, args->pmdp);
 262         pmd = READ_ONCE(*args->pmdp);
 263         WARN_ON(!pmd_none(pmd));
 264
 265         pmd = pfn_pmd(args->pmd_pfn, args->page_prot);
 266         pmd = pmd_wrprotect(pmd);
 267         pmd = pmd_mkclean(pmd);
 268         set_pmd_at(args->mm, vaddr, args->pmdp, pmd);
 269         flush_dcache_page(page);
 270         pmd = pmd_mkwrite(pmd);
 271         pmd = pmd_mkdirty(pmd);
 272         pmdp_set_access_flags(args->vma, vaddr, args->pmdp, pmd, 1);
 273         pmd = READ_ONCE(*args->pmdp);
 274         WARN_ON(!(pmd_write(pmd) && pmd_dirty(pmd)));
 275         pmdp_huge_get_and_clear_full(args->vma, vaddr, args->pmdp, 1);
 276         pmd = READ_ONCE(*args->pmdp);
 277         WARN_ON(!pmd_none(pmd));
 278
 279         pmd = pmd_mkhuge(pfn_pmd(args->pmd_pfn, args->page_prot));
 280         pmd = pmd_mkyoung(pmd);
 281         set_pmd_at(args->mm, vaddr, args->pmdp, pmd);
 282         flush_dcache_page(page);
 283         pmdp_test_and_clear_young(args->vma, vaddr, args->pmdp);
 284         pmd = READ_ONCE(*args->pmdp);
 285         WARN_ON(pmd_young(pmd));
 286
 287         /*  Clear the pte entries  */
 288         pmdp_huge_get_and_clear(args->mm, vaddr, args->pmdp);
 289         pgtable_trans_huge_withdraw(args->mm, args->pmdp);
 290 }
 291
 292 static void __init pmd_leaf_tests(struct pgtable_debug_args *args)
 293 {
 294         pmd_t pmd;
 295
 296         if (!has_transparent_hugepage())
 297                 return;
 298
 299         pr_debug("Validating PMD leaf\n");
 300         pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot);
 301
 302         /*
 303          * PMD based THP is a leaf entry.
 304          */
 305         pmd = pmd_mkhuge(pmd);
 306         WARN_ON(!pmd_leaf(pmd));
 307 }
 308
 309 static void __init pmd_savedwrite_tests(struct pgtable_debug_args *args)
 310 {
 311         pmd_t pmd;
 312
 313         if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
 314                 return;
 315
 316         if (!has_transparent_hugepage())
 317                 return;
 318
 319         pr_debug("Validating PMD saved write\n");
 320         pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot_none);
 321         WARN_ON(!pmd_savedwrite(pmd_mk_savedwrite(pmd_clear_savedwrite(pmd))));
 322         WARN_ON(pmd_savedwrite(pmd_clear_savedwrite(pmd_mk_savedwrite(pmd))));
 323 }
 324
 325 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
 326 static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx)
 327 {
 328         pgprot_t prot = protection_map[idx];
 329         unsigned long val = idx, *ptr = &val;
 330         pud_t pud;
 331
 332         if (!has_transparent_hugepage())
 333                 return;
 334
 335         pr_debug("Validating PUD basic (%pGv)\n", ptr);
 336         pud = pfn_pud(args->fixed_pud_pfn, prot);
 337
 338         /*
 339          * This test needs to be executed after the given page table entry
 340          * is created with pfn_pud() to make sure that protection_map[idx]
 341          * does not have the dirty bit enabled from the beginning. This is
 342          * important for platforms like arm64 where (!PTE_RDONLY) indicate
 343          * dirty bit being set.
 344          */
 345         WARN_ON(pud_dirty(pud_wrprotect(pud)));
 346
 347         WARN_ON(!pud_same(pud, pud));
 348         WARN_ON(!pud_young(pud_mkyoung(pud_mkold(pud))));
 349         WARN_ON(!pud_dirty(pud_mkdirty(pud_mkclean(pud))));
 350         WARN_ON(pud_dirty(pud_mkclean(pud_mkdirty(pud))));
 351         WARN_ON(!pud_write(pud_mkwrite(pud_wrprotect(pud))));
 352         WARN_ON(pud_write(pud_wrprotect(pud_mkwrite(pud))));
 353         WARN_ON(pud_young(pud_mkold(pud_mkyoung(pud))));
 354         WARN_ON(pud_dirty(pud_wrprotect(pud_mkclean(pud))));
 355         WARN_ON(!pud_dirty(pud_wrprotect(pud_mkdirty(pud))));
 356
 357         if (mm_pmd_folded(args->mm))
 358                 return;
 359
 360         /*
 361          * A huge page does not point to next level page table
 362          * entry. Hence this must qualify as pud_bad().
 363          */
 364         WARN_ON(!pud_bad(pud_mkhuge(pud)));
 365 }
 366
 367 static void __init pud_advanced_tests(struct pgtable_debug_args *args)
 368 {
 369         struct page *page;
 370         unsigned long vaddr = args->vaddr;
 371         pud_t pud;
 372
 373         if (!has_transparent_hugepage())
 374                 return;
 375
 376         page = (args->pud_pfn != ULONG_MAX) ? pfn_to_page(args->pud_pfn) : NULL;
 377         if (!page)
 378                 return;
 379
 380         /*
 381          * flush_dcache_page() is called after set_pud_at() to clear
 382          * PG_arch_1 for the page on ARM64. The page flag isn't cleared
 383          * when it's released and page allocation check will fail when
 384          * the page is allocated again. For architectures other than ARM64,
 385          * the unexpected overhead of cache flushing is acceptable.
 386          */
 387         pr_debug("Validating PUD advanced\n");
 388         /* Align the address wrt HPAGE_PUD_SIZE */
 389         vaddr &= HPAGE_PUD_MASK;
 390
 391         pud = pfn_pud(args->pud_pfn, args->page_prot);
 392         set_pud_at(args->mm, vaddr, args->pudp, pud);
 393         flush_dcache_page(page);
 394         pudp_set_wrprotect(args->mm, vaddr, args->pudp);
 395         pud = READ_ONCE(*args->pudp);
 396         WARN_ON(pud_write(pud));
 397
 398 #ifndef __PAGETABLE_PMD_FOLDED
 399         pudp_huge_get_and_clear(args->mm, vaddr, args->pudp);
 400         pud = READ_ONCE(*args->pudp);
 401         WARN_ON(!pud_none(pud));
 402 #endif /* __PAGETABLE_PMD_FOLDED */
 403         pud = pfn_pud(args->pud_pfn, args->page_prot);
 404         pud = pud_wrprotect(pud);
 405         pud = pud_mkclean(pud);
 406         set_pud_at(args->mm, vaddr, args->pudp, pud);
 407         flush_dcache_page(page);
 408         pud = pud_mkwrite(pud);
 409         pud = pud_mkdirty(pud);
 410         pudp_set_access_flags(args->vma, vaddr, args->pudp, pud, 1);
 411         pud = READ_ONCE(*args->pudp);
 412         WARN_ON(!(pud_write(pud) && pud_dirty(pud)));
 413
 414 #ifndef __PAGETABLE_PMD_FOLDED
 415         pudp_huge_get_and_clear_full(args->mm, vaddr, args->pudp, 1);
 416         pud = READ_ONCE(*args->pudp);
 417         WARN_ON(!pud_none(pud));
 418 #endif /* __PAGETABLE_PMD_FOLDED */
 419
 420         pud = pfn_pud(args->pud_pfn, args->page_prot);
 421         pud = pud_mkyoung(pud);
 422         set_pud_at(args->mm, vaddr, args->pudp, pud);
 423         flush_dcache_page(page);
 424         pudp_test_and_clear_young(args->vma, vaddr, args->pudp);
 425         pud = READ_ONCE(*args->pudp);
 426         WARN_ON(pud_young(pud));
 427
 428         pudp_huge_get_and_clear(args->mm, vaddr, args->pudp);
 429 }
 430
 431 static void __init pud_leaf_tests(struct pgtable_debug_args *args)
 432 {
 433         pud_t pud;
 434
 435         if (!has_transparent_hugepage())
 436                 return;
 437
 438         pr_debug("Validating PUD leaf\n");
 439         pud = pfn_pud(args->fixed_pud_pfn, args->page_prot);
 440         /*
 441          * PUD based THP is a leaf entry.
 442          */
 443         pud = pud_mkhuge(pud);
 444         WARN_ON(!pud_leaf(pud));
 445 }
 446 #else  /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
 447 static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx) { }
 448 static void __init pud_advanced_tests(struct pgtable_debug_args *args) { }
 449 static void __init pud_leaf_tests(struct pgtable_debug_args *args) { }
 450 #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
 451 #else  /* !CONFIG_TRANSPARENT_HUGEPAGE */
 452 static void __init pmd_basic_tests(struct pgtable_debug_args *args, int idx) { }
 453 static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx) { }
 454 static void __init pmd_advanced_tests(struct pgtable_debug_args *args) { }
 455 static void __init pud_advanced_tests(struct pgtable_debug_args *args) { }
 456 static void __init pmd_leaf_tests(struct pgtable_debug_args *args) { }
 457 static void __init pud_leaf_tests(struct pgtable_debug_args *args) { }
 458 static void __init pmd_savedwrite_tests(struct pgtable_debug_args *args) { }
 459 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 460
 461 #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
 462 static void __init pmd_huge_tests(struct pgtable_debug_args *args)
 463 {
 464         pmd_t pmd;
 465
 466         if (!arch_vmap_pmd_supported(args->page_prot))
 467                 return;
 468
 469         pr_debug("Validating PMD huge\n");
 470         /*
 471          * X86 defined pmd_set_huge() verifies that the given
 472          * PMD is not a populated non-leaf entry.
 473          */
 474         WRITE_ONCE(*args->pmdp, __pmd(0));
 475         WARN_ON(!pmd_set_huge(args->pmdp, __pfn_to_phys(args->fixed_pmd_pfn), args->page_prot));
 476         WARN_ON(!pmd_clear_huge(args->pmdp));
 477         pmd = READ_ONCE(*args->pmdp);
 478         WARN_ON(!pmd_none(pmd));
 479 }
 480
 481 static void __init pud_huge_tests(struct pgtable_debug_args *args)
 482 {
 483         pud_t pud;
 484
 485         if (!arch_vmap_pud_supported(args->page_prot))
 486                 return;
 487
 488         pr_debug("Validating PUD huge\n");
 489         /*
 490          * X86 defined pud_set_huge() verifies that the given
 491          * PUD is not a populated non-leaf entry.
 492          */
 493         WRITE_ONCE(*args->pudp, __pud(0));
 494         WARN_ON(!pud_set_huge(args->pudp, __pfn_to_phys(args->fixed_pud_pfn), args->page_prot));
 495         WARN_ON(!pud_clear_huge(args->pudp));
 496         pud = READ_ONCE(*args->pudp);
 497         WARN_ON(!pud_none(pud));
 498 }
 499 #else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
 500 static void __init pmd_huge_tests(struct pgtable_debug_args *args) { }
 501 static void __init pud_huge_tests(struct pgtable_debug_args *args) { }
 502 #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
 503
 504 static void __init p4d_basic_tests(struct pgtable_debug_args *args)
 505 {
 506         p4d_t p4d;
 507
 508         pr_debug("Validating P4D basic\n");
 509         memset(&p4d, RANDOM_NZVALUE, sizeof(p4d_t));
 510         WARN_ON(!p4d_same(p4d, p4d));
 511 }
 512
 513 static void __init pgd_basic_tests(struct pgtable_debug_args *args)
 514 {
 515         pgd_t pgd;
 516
 517         pr_debug("Validating PGD basic\n");
 518         memset(&pgd, RANDOM_NZVALUE, sizeof(pgd_t));
 519         WARN_ON(!pgd_same(pgd, pgd));
 520 }
 521
 522 #ifndef __PAGETABLE_PUD_FOLDED
 523 static void __init pud_clear_tests(struct pgtable_debug_args *args)
 524 {
 525         pud_t pud = READ_ONCE(*args->pudp);
 526
 527         if (mm_pmd_folded(args->mm))
 528                 return;
 529
 530         pr_debug("Validating PUD clear\n");
 531         pud = __pud(pud_val(pud) | RANDOM_ORVALUE);
 532         WRITE_ONCE(*args->pudp, pud);
 533         pud_clear(args->pudp);
 534         pud = READ_ONCE(*args->pudp);
 535         WARN_ON(!pud_none(pud));
 536 }
 537
 538 static void __init pud_populate_tests(struct pgtable_debug_args *args)
 539 {
 540         pud_t pud;
 541
 542         if (mm_pmd_folded(args->mm))
 543                 return;
 544
 545         pr_debug("Validating PUD populate\n");
 546         /*
 547          * This entry points to next level page table page.
 548          * Hence this must not qualify as pud_bad().
 549          */
 550         pud_populate(args->mm, args->pudp, args->start_pmdp);
 551         pud = READ_ONCE(*args->pudp);
 552         WARN_ON(pud_bad(pud));
 553 }
 554 #else  /* !__PAGETABLE_PUD_FOLDED */
 555 static void __init pud_clear_tests(struct pgtable_debug_args *args) { }
 556 static void __init pud_populate_tests(struct pgtable_debug_args *args) { }
 557 #endif /* PAGETABLE_PUD_FOLDED */
 558
 559 #ifndef __PAGETABLE_P4D_FOLDED
 560 static void __init p4d_clear_tests(struct pgtable_debug_args *args)
 561 {
 562         p4d_t p4d = READ_ONCE(*args->p4dp);
 563
 564         if (mm_pud_folded(args->mm))
 565                 return;
 566
 567         pr_debug("Validating P4D clear\n");
 568         p4d = __p4d(p4d_val(p4d) | RANDOM_ORVALUE);
 569         WRITE_ONCE(*args->p4dp, p4d);
 570         p4d_clear(args->p4dp);
 571         p4d = READ_ONCE(*args->p4dp);
 572         WARN_ON(!p4d_none(p4d));
 573 }
 574
 575 static void __init p4d_populate_tests(struct pgtable_debug_args *args)
 576 {
 577         p4d_t p4d;
 578
 579         if (mm_pud_folded(args->mm))
 580                 return;
 581
 582         pr_debug("Validating P4D populate\n");
 583         /*
 584          * This entry points to next level page table page.
 585          * Hence this must not qualify as p4d_bad().
 586          */
 587         pud_clear(args->pudp);
 588         p4d_clear(args->p4dp);
 589         p4d_populate(args->mm, args->p4dp, args->start_pudp);
 590         p4d = READ_ONCE(*args->p4dp);
 591         WARN_ON(p4d_bad(p4d));
 592 }
 593
 594 static void __init pgd_clear_tests(struct pgtable_debug_args *args)
 595 {
 596         pgd_t pgd = READ_ONCE(*(args->pgdp));
 597
 598         if (mm_p4d_folded(args->mm))
 599                 return;
 600
 601         pr_debug("Validating PGD clear\n");
 602         pgd = __pgd(pgd_val(pgd) | RANDOM_ORVALUE);
 603         WRITE_ONCE(*args->pgdp, pgd);
 604         pgd_clear(args->pgdp);
 605         pgd = READ_ONCE(*args->pgdp);
 606         WARN_ON(!pgd_none(pgd));
 607 }
 608
 609 static void __init pgd_populate_tests(struct pgtable_debug_args *args)
 610 {
 611         pgd_t pgd;
 612
 613         if (mm_p4d_folded(args->mm))
 614                 return;
 615
 616         pr_debug("Validating PGD populate\n");
 617         /*
 618          * This entry points to next level page table page.
 619          * Hence this must not qualify as pgd_bad().
 620          */
 621         p4d_clear(args->p4dp);
 622         pgd_clear(args->pgdp);
 623         pgd_populate(args->mm, args->pgdp, args->start_p4dp);
 624         pgd = READ_ONCE(*args->pgdp);
 625         WARN_ON(pgd_bad(pgd));
 626 }
 627 #else  /* !__PAGETABLE_P4D_FOLDED */
 628 static void __init p4d_clear_tests(struct pgtable_debug_args *args) { }
 629 static void __init pgd_clear_tests(struct pgtable_debug_args *args) { }
 630 static void __init p4d_populate_tests(struct pgtable_debug_args *args) { }
 631 static void __init pgd_populate_tests(struct pgtable_debug_args *args) { }
 632 #endif /* PAGETABLE_P4D_FOLDED */
 633
 634 static void __init pte_clear_tests(struct pgtable_debug_args *args)
 635 {
 636         struct page *page;
 637         pte_t pte = pfn_pte(args->pte_pfn, args->page_prot);
 638
 639         page = (args->pte_pfn != ULONG_MAX) ? pfn_to_page(args->pte_pfn) : NULL;
 640         if (!page)
 641                 return;
 642
 643         /*
 644          * flush_dcache_page() is called after set_pte_at() to clear
 645          * PG_arch_1 for the page on ARM64. The page flag isn't cleared
 646          * when it's released and page allocation check will fail when
 647          * the page is allocated again. For architectures other than ARM64,
 648          * the unexpected overhead of cache flushing is acceptable.
 649          */
 650         pr_debug("Validating PTE clear\n");
 651 #ifndef CONFIG_RISCV
 652         pte = __pte(pte_val(pte) | RANDOM_ORVALUE);
 653 #endif
 654         set_pte_at(args->mm, args->vaddr, args->ptep, pte);
 655         flush_dcache_page(page);
 656         barrier();
 657         pte_clear(args->mm, args->vaddr, args->ptep);
 658         pte = ptep_get(args->ptep);
 659         WARN_ON(!pte_none(pte));
 660 }
 661
 662 static void __init pmd_clear_tests(struct pgtable_debug_args *args)
 663 {
 664         pmd_t pmd = READ_ONCE(*args->pmdp);
 665
 666         pr_debug("Validating PMD clear\n");
 667         pmd = __pmd(pmd_val(pmd) | RANDOM_ORVALUE);
 668         WRITE_ONCE(*args->pmdp, pmd);
 669         pmd_clear(args->pmdp);
 670         pmd = READ_ONCE(*args->pmdp);
 671         WARN_ON(!pmd_none(pmd));
 672 }
 673
 674 static void __init pmd_populate_tests(struct pgtable_debug_args *args)
 675 {
 676         pmd_t pmd;
 677
 678         pr_debug("Validating PMD populate\n");
 679         /*
 680          * This entry points to next level page table page.
 681          * Hence this must not qualify as pmd_bad().
 682          */
 683         pmd_populate(args->mm, args->pmdp, args->start_ptep);
 684         pmd = READ_ONCE(*args->pmdp);
 685         WARN_ON(pmd_bad(pmd));
 686 }
 687
 688 static void __init pte_special_tests(struct pgtable_debug_args *args)
 689 {
 690         pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot);
 691
 692         if (!IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL))
 693                 return;
 694
 695         pr_debug("Validating PTE special\n");
 696         WARN_ON(!pte_special(pte_mkspecial(pte)));
 697 }
 698
 699 static void __init pte_protnone_tests(struct pgtable_debug_args *args)
 700 {
 701         pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot_none);
 702
 703         if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
 704                 return;
 705
 706         pr_debug("Validating PTE protnone\n");
 707         WARN_ON(!pte_protnone(pte));
 708         WARN_ON(!pte_present(pte));
 709 }
 710
 711 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 712 static void __init pmd_protnone_tests(struct pgtable_debug_args *args)
 713 {
 714         pmd_t pmd;
 715
 716         if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
 717                 return;
 718
 719         if (!has_transparent_hugepage())
 720                 return;
 721
 722         pr_debug("Validating PMD protnone\n");
 723         pmd = pmd_mkhuge(pfn_pmd(args->fixed_pmd_pfn, args->page_prot_none));
 724         WARN_ON(!pmd_protnone(pmd));
 725         WARN_ON(!pmd_present(pmd));
 726 }
 727 #else  /* !CONFIG_TRANSPARENT_HUGEPAGE */
 728 static void __init pmd_protnone_tests(struct pgtable_debug_args *args) { }
 729 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 730
 731 #ifdef CONFIG_ARCH_HAS_PTE_DEVMAP
 732 static void __init pte_devmap_tests(struct pgtable_debug_args *args)
 733 {
 734         pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot);
 735
 736         pr_debug("Validating PTE devmap\n");
 737         WARN_ON(!pte_devmap(pte_mkdevmap(pte)));
 738 }
 739
 740 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 741 static void __init pmd_devmap_tests(struct pgtable_debug_args *args)
 742 {
 743         pmd_t pmd;
 744
 745         if (!has_transparent_hugepage())
 746                 return;
 747
 748         pr_debug("Validating PMD devmap\n");
 749         pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot);
 750         WARN_ON(!pmd_devmap(pmd_mkdevmap(pmd)));
 751 }
 752
 753 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
 754 static void __init pud_devmap_tests(struct pgtable_debug_args *args)
 755 {
 756         pud_t pud;
 757
 758         if (!has_transparent_hugepage())
 759                 return;
 760
 761         pr_debug("Validating PUD devmap\n");
 762         pud = pfn_pud(args->fixed_pud_pfn, args->page_prot);
 763         WARN_ON(!pud_devmap(pud_mkdevmap(pud)));
 764 }
 765 #else  /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
 766 static void __init pud_devmap_tests(struct pgtable_debug_args *args) { }
 767 #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
 768 #else  /* CONFIG_TRANSPARENT_HUGEPAGE */
 769 static void __init pmd_devmap_tests(struct pgtable_debug_args *args) { }
 770 static void __init pud_devmap_tests(struct pgtable_debug_args *args) { }
 771 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 772 #else
 773 static void __init pte_devmap_tests(struct pgtable_debug_args *args) { }
 774 static void __init pmd_devmap_tests(struct pgtable_debug_args *args) { }
 775 static void __init pud_devmap_tests(struct pgtable_debug_args *args) { }
 776 #endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */
 777
 778 static void __init pte_soft_dirty_tests(struct pgtable_debug_args *args)
 779 {
 780         pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot);
 781
 782         if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
 783                 return;
 784
 785         pr_debug("Validating PTE soft dirty\n");
 786         WARN_ON(!pte_soft_dirty(pte_mksoft_dirty(pte)));
 787         WARN_ON(pte_soft_dirty(pte_clear_soft_dirty(pte)));
 788 }
 789
 790 static void __init pte_swap_soft_dirty_tests(struct pgtable_debug_args *args)
 791 {
 792         pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot);
 793
 794         if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
 795                 return;
 796
 797         pr_debug("Validating PTE swap soft dirty\n");
 798         WARN_ON(!pte_swp_soft_dirty(pte_swp_mksoft_dirty(pte)));
 799         WARN_ON(pte_swp_soft_dirty(pte_swp_clear_soft_dirty(pte)));
 800 }
 801
 802 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 803 static void __init pmd_soft_dirty_tests(struct pgtable_debug_args *args)
 804 {
 805         pmd_t pmd;
 806
 807         if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
 808                 return;
 809
 810         if (!has_transparent_hugepage())
 811                 return;
 812
 813         pr_debug("Validating PMD soft dirty\n");
 814         pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot);
 815         WARN_ON(!pmd_soft_dirty(pmd_mksoft_dirty(pmd)));
 816         WARN_ON(pmd_soft_dirty(pmd_clear_soft_dirty(pmd)));
 817 }
 818
 819 static void __init pmd_swap_soft_dirty_tests(struct pgtable_debug_args *args)
 820 {
 821         pmd_t pmd;
 822
 823         if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY) ||
 824                 !IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION))
 825                 return;
 826
 827         if (!has_transparent_hugepage())
 828                 return;
 829
 830         pr_debug("Validating PMD swap soft dirty\n");
 831         pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot);
 832         WARN_ON(!pmd_swp_soft_dirty(pmd_swp_mksoft_dirty(pmd)));
 833         WARN_ON(pmd_swp_soft_dirty(pmd_swp_clear_soft_dirty(pmd)));
 834 }
 835 #else  /* !CONFIG_TRANSPARENT_HUGEPAGE */
 836 static void __init pmd_soft_dirty_tests(struct pgtable_debug_args *args) { }
 837 static void __init pmd_swap_soft_dirty_tests(struct pgtable_debug_args *args) { }
 838 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 839
 840 static void __init pte_swap_tests(struct pgtable_debug_args *args)
 841 {
 842         swp_entry_t swp;
 843         pte_t pte;
 844
 845         pr_debug("Validating PTE swap\n");
 846         pte = pfn_pte(args->fixed_pte_pfn, args->page_prot);
 847         swp = __pte_to_swp_entry(pte);
 848         pte = __swp_entry_to_pte(swp);
 849         WARN_ON(args->fixed_pte_pfn != pte_pfn(pte));
 850 }
 851
 852 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
 853 static void __init pmd_swap_tests(struct pgtable_debug_args *args)
 854 {
 855         swp_entry_t swp;
 856         pmd_t pmd;
 857
 858         if (!has_transparent_hugepage())
 859                 return;
 860
 861         pr_debug("Validating PMD swap\n");
 862         pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot);
 863         swp = __pmd_to_swp_entry(pmd);
 864         pmd = __swp_entry_to_pmd(swp);
 865         WARN_ON(args->fixed_pmd_pfn != pmd_pfn(pmd));
 866 }
 867 #else  /* !CONFIG_ARCH_ENABLE_THP_MIGRATION */
 868 static void __init pmd_swap_tests(struct pgtable_debug_args *args) { }
 869 #endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
 870
 871 static void __init swap_migration_tests(struct pgtable_debug_args *args)
 872 {
 873         struct page *page;
 874         swp_entry_t swp;
 875
 876         if (!IS_ENABLED(CONFIG_MIGRATION))
 877                 return;
 878
 879         /*
 880          * swap_migration_tests() requires a dedicated page as it needs to
 881          * be locked before creating a migration entry from it. Locking the
 882          * page that actually maps kernel text ('start_kernel') can be real
 883          * problematic. Lets use the allocated page explicitly for this
 884          * purpose.
 885          */
 886         page = (args->pte_pfn != ULONG_MAX) ? pfn_to_page(args->pte_pfn) : NULL;
 887         if (!page)
 888                 return;
 889
 890         pr_debug("Validating swap migration\n");
 891
 892         /*
 893          * make_migration_entry() expects given page to be
 894          * locked, otherwise it stumbles upon a BUG_ON().
 895          */
 896         __SetPageLocked(page);
 897         swp = make_writable_migration_entry(page_to_pfn(page));
 898         WARN_ON(!is_migration_entry(swp));
 899         WARN_ON(!is_writable_migration_entry(swp));
 900
 901         swp = make_readable_migration_entry(swp_offset(swp));
 902         WARN_ON(!is_migration_entry(swp));
 903         WARN_ON(is_writable_migration_entry(swp));
 904
 905         swp = make_readable_migration_entry(page_to_pfn(page));
 906         WARN_ON(!is_migration_entry(swp));
 907         WARN_ON(is_writable_migration_entry(swp));
 908         __ClearPageLocked(page);
 909 }
 910
 911 #ifdef CONFIG_HUGETLB_PAGE
 912 static void __init hugetlb_basic_tests(struct pgtable_debug_args *args)
 913 {
 914         struct page *page;
 915         pte_t pte;
 916
 917         pr_debug("Validating HugeTLB basic\n");
 918         /*
 919          * Accessing the page associated with the pfn is safe here,
 920          * as it was previously derived from a real kernel symbol.
 921          */
 922         page = pfn_to_page(args->fixed_pmd_pfn);
 923         pte = mk_huge_pte(page, args->page_prot);
 924
 925         WARN_ON(!huge_pte_dirty(huge_pte_mkdirty(pte)));
 926         WARN_ON(!huge_pte_write(huge_pte_mkwrite(huge_pte_wrprotect(pte))));
 927         WARN_ON(huge_pte_write(huge_pte_wrprotect(huge_pte_mkwrite(pte))));
 928
 929 #ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB
 930         pte = pfn_pte(args->fixed_pmd_pfn, args->page_prot);
 931
 932         WARN_ON(!pte_huge(pte_mkhuge(pte)));
 933 #endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */
 934 }
 935 #else  /* !CONFIG_HUGETLB_PAGE */
 936 static void __init hugetlb_basic_tests(struct pgtable_debug_args *args) { }
 937 #endif /* CONFIG_HUGETLB_PAGE */
 938
 939 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 940 static void __init pmd_thp_tests(struct pgtable_debug_args *args)
 941 {
 942         pmd_t pmd;
 943
 944         if (!has_transparent_hugepage())
 945                 return;
 946
 947         pr_debug("Validating PMD based THP\n");
 948         /*
 949          * pmd_trans_huge() and pmd_present() must return positive after
 950          * MMU invalidation with pmd_mkinvalid(). This behavior is an
 951          * optimization for transparent huge page. pmd_trans_huge() must
 952          * be true if pmd_page() returns a valid THP to avoid taking the
 953          * pmd_lock when others walk over non transhuge pmds (i.e. there
 954          * are no THP allocated). Especially when splitting a THP and
 955          * removing the present bit from the pmd, pmd_trans_huge() still
 956          * needs to return true. pmd_present() should be true whenever
 957          * pmd_trans_huge() returns true.
 958          */
 959         pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot);
 960         WARN_ON(!pmd_trans_huge(pmd_mkhuge(pmd)));
 961
 962 #ifndef __HAVE_ARCH_PMDP_INVALIDATE
 963         WARN_ON(!pmd_trans_huge(pmd_mkinvalid(pmd_mkhuge(pmd))));
 964         WARN_ON(!pmd_present(pmd_mkinvalid(pmd_mkhuge(pmd))));
 965 #endif /* __HAVE_ARCH_PMDP_INVALIDATE */
 966 }
 967
 968 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
 969 static void __init pud_thp_tests(struct pgtable_debug_args *args)
 970 {
 971         pud_t pud;
 972
 973         if (!has_transparent_hugepage())
 974                 return;
 975
 976         pr_debug("Validating PUD based THP\n");
 977         pud = pfn_pud(args->fixed_pud_pfn, args->page_prot);
 978         WARN_ON(!pud_trans_huge(pud_mkhuge(pud)));
 979
 980         /*
 981          * pud_mkinvalid() has been dropped for now. Enable back
 982          * these tests when it comes back with a modified pud_present().
 983          *
 984          * WARN_ON(!pud_trans_huge(pud_mkinvalid(pud_mkhuge(pud))));
 985          * WARN_ON(!pud_present(pud_mkinvalid(pud_mkhuge(pud))));
 986          */
 987 }
 988 #else  /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
 989 static void __init pud_thp_tests(struct pgtable_debug_args *args) { }
 990 #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
 991 #else  /* !CONFIG_TRANSPARENT_HUGEPAGE */
 992 static void __init pmd_thp_tests(struct pgtable_debug_args *args) { }
 993 static void __init pud_thp_tests(struct pgtable_debug_args *args) { }
 994 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 995
 996 static unsigned long __init get_random_vaddr(void)
 997 {
 998         unsigned long random_vaddr, random_pages, total_user_pages;
 999
1000         total_user_pages = (TASK_SIZE - FIRST_USER_ADDRESS) / PAGE_SIZE;
1001
1002         random_pages = get_random_long() % total_user_pages;
1003         random_vaddr = FIRST_USER_ADDRESS + random_pages * PAGE_SIZE;
1004
1005         return random_vaddr;
1006 }
1007
1008 static void __init destroy_args(struct pgtable_debug_args *args)
1009 {
1010         struct page *page = NULL;
1011
1012         /* Free (huge) page */
1013         if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
1014             IS_ENABLED(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD) &&
1015             has_transparent_hugepage() &&
1016             args->pud_pfn != ULONG_MAX) {
1017                 if (args->is_contiguous_page) {
1018                         free_contig_range(args->pud_pfn,
1019                                           (1 << (HPAGE_PUD_SHIFT - PAGE_SHIFT)));
1020                 } else {
1021                         page = pfn_to_page(args->pud_pfn);
1022                         __free_pages(page, HPAGE_PUD_SHIFT - PAGE_SHIFT);
1023                 }
1024
1025                 args->pud_pfn = ULONG_MAX;
1026                 args->pmd_pfn = ULONG_MAX;
1027                 args->pte_pfn = ULONG_MAX;
1028         }
1029
1030         if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
1031             has_transparent_hugepage() &&
1032             args->pmd_pfn != ULONG_MAX) {
1033                 if (args->is_contiguous_page) {
1034                         free_contig_range(args->pmd_pfn, (1 << HPAGE_PMD_ORDER));
1035                 } else {
1036                         page = pfn_to_page(args->pmd_pfn);
1037                         __free_pages(page, HPAGE_PMD_ORDER);
1038                 }
1039
1040                 args->pmd_pfn = ULONG_MAX;
1041                 args->pte_pfn = ULONG_MAX;
1042         }
1043
1044         if (args->pte_pfn != ULONG_MAX) {
1045                 page = pfn_to_page(args->pte_pfn);
1046                 __free_pages(page, 0);
1047
1048                 args->pte_pfn = ULONG_MAX;
1049         }
1050
1051         /* Free page table entries */
1052         if (args->start_ptep) {
1053                 pte_free(args->mm, args->start_ptep);
1054                 mm_dec_nr_ptes(args->mm);
1055         }
1056
1057         if (args->start_pmdp) {
1058                 pmd_free(args->mm, args->start_pmdp);
1059                 mm_dec_nr_pmds(args->mm);
1060         }
1061
1062         if (args->start_pudp) {
1063                 pud_free(args->mm, args->start_pudp);
1064                 mm_dec_nr_puds(args->mm);
1065         }
1066
1067         if (args->start_p4dp)
1068                 p4d_free(args->mm, args->start_p4dp);
1069
1070         /* Free vma and mm struct */
1071         if (args->vma)
1072                 vm_area_free(args->vma);
1073
1074         if (args->mm)
1075                 mmdrop(args->mm);
1076 }
1077
1078 static struct page * __init
1079 debug_vm_pgtable_alloc_huge_page(struct pgtable_debug_args *args, int order)
1080 {
1081         struct page *page = NULL;
1082
1083 #ifdef CONFIG_CONTIG_ALLOC
1084         if (order >= MAX_ORDER) {
1085                 page = alloc_contig_pages((1 << order), GFP_KERNEL,
1086                                           first_online_node, NULL);
1087                 if (page) {
1088                         args->is_contiguous_page = true;
1089                         return page;
1090                 }
1091         }
1092 #endif
1093
1094         if (order < MAX_ORDER)
1095                 page = alloc_pages(GFP_KERNEL, order);
1096
1097         return page;
1098 }
1099
1100 static int __init init_args(struct pgtable_debug_args *args)
1101 {
1102         struct page *page = NULL;
1103         phys_addr_t phys;
1104         int ret = 0;
1105
1106         /*
1107          * Initialize the debugging data.
1108          *
1109          * __P000 (or even __S000) will help create page table entries with
1110          * PROT_NONE permission as required for pxx_protnone_tests().
1111          */
1112         memset(args, 0, sizeof(*args));
1113         args->vaddr              = get_random_vaddr();
1114         args->page_prot          = vm_get_page_prot(VMFLAGS);
1115         args->page_prot_none     = __P000;
1116         args->is_contiguous_page = false;
1117         args->pud_pfn            = ULONG_MAX;
1118         args->pmd_pfn            = ULONG_MAX;
1119         args->pte_pfn            = ULONG_MAX;
1120         args->fixed_pgd_pfn      = ULONG_MAX;
1121         args->fixed_p4d_pfn      = ULONG_MAX;
1122         args->fixed_pud_pfn      = ULONG_MAX;
1123         args->fixed_pmd_pfn      = ULONG_MAX;
1124         args->fixed_pte_pfn      = ULONG_MAX;
1125
1126         /* Allocate mm and vma */
1127         args->mm = mm_alloc();
1128         if (!args->mm) {
1129                 pr_err("Failed to allocate mm struct\n");
1130                 ret = -ENOMEM;
1131                 goto error;
1132         }
1133
1134         args->vma = vm_area_alloc(args->mm);
1135         if (!args->vma) {
1136                 pr_err("Failed to allocate vma\n");
1137                 ret = -ENOMEM;
1138                 goto error;
1139         }
1140
1141         /*
1142          * Allocate page table entries. They will be modified in the tests.
1143          * Lets save the page table entries so that they can be released
1144          * when the tests are completed.
1145          */
1146         args->pgdp = pgd_offset(args->mm, args->vaddr);
1147         args->p4dp = p4d_alloc(args->mm, args->pgdp, args->vaddr);
1148         if (!args->p4dp) {
1149                 pr_err("Failed to allocate p4d entries\n");
1150                 ret = -ENOMEM;
1151                 goto error;
1152         }
1153         args->start_p4dp = p4d_offset(args->pgdp, 0UL);
1154         WARN_ON(!args->start_p4dp);
1155
1156         args->pudp = pud_alloc(args->mm, args->p4dp, args->vaddr);
1157         if (!args->pudp) {
1158                 pr_err("Failed to allocate pud entries\n");
1159                 ret = -ENOMEM;
1160                 goto error;
1161         }
1162         args->start_pudp = pud_offset(args->p4dp, 0UL);
1163         WARN_ON(!args->start_pudp);
1164
1165         args->pmdp = pmd_alloc(args->mm, args->pudp, args->vaddr);
1166         if (!args->pmdp) {
1167                 pr_err("Failed to allocate pmd entries\n");
1168                 ret = -ENOMEM;
1169                 goto error;
1170         }
1171         args->start_pmdp = pmd_offset(args->pudp, 0UL);
1172         WARN_ON(!args->start_pmdp);
1173
1174         if (pte_alloc(args->mm, args->pmdp)) {
1175                 pr_err("Failed to allocate pte entries\n");
1176                 ret = -ENOMEM;
1177                 goto error;
1178         }
1179         args->start_ptep = pmd_pgtable(READ_ONCE(*args->pmdp));
1180         WARN_ON(!args->start_ptep);
1181
1182         /*
1183          * PFN for mapping at PTE level is determined from a standard kernel
1184          * text symbol. But pfns for higher page table levels are derived by
1185          * masking lower bits of this real pfn. These derived pfns might not
1186          * exist on the platform but that does not really matter as pfn_pxx()
1187          * helpers will still create appropriate entries for the test. This
1188          * helps avoid large memory block allocations to be used for mapping
1189          * at higher page table levels in some of the tests.
1190          */
1191         phys = __pa_symbol(&start_kernel);
1192         args->fixed_pgd_pfn = __phys_to_pfn(phys & PGDIR_MASK);
1193         args->fixed_p4d_pfn = __phys_to_pfn(phys & P4D_MASK);
1194         args->fixed_pud_pfn = __phys_to_pfn(phys & PUD_MASK);
1195         args->fixed_pmd_pfn = __phys_to_pfn(phys & PMD_MASK);
1196         args->fixed_pte_pfn = __phys_to_pfn(phys & PAGE_MASK);
1197         WARN_ON(!pfn_valid(args->fixed_pte_pfn));
1198
1199         /*
1200          * Allocate (huge) pages because some of the tests need to access
1201          * the data in the pages. The corresponding tests will be skipped
1202          * if we fail to allocate (huge) pages.
1203          */
1204         if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
1205             IS_ENABLED(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD) &&
1206             has_transparent_hugepage()) {
1207                 page = debug_vm_pgtable_alloc_huge_page(args,
1208                                 HPAGE_PUD_SHIFT - PAGE_SHIFT);
1209                 if (page) {
1210                         args->pud_pfn = page_to_pfn(page);
1211                         args->pmd_pfn = args->pud_pfn;
1212                         args->pte_pfn = args->pud_pfn;
1213                         return 0;
1214                 }
1215         }
1216
1217         if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
1218             has_transparent_hugepage()) {
1219                 page = debug_vm_pgtable_alloc_huge_page(args, HPAGE_PMD_ORDER);
1220                 if (page) {
1221                         args->pmd_pfn = page_to_pfn(page);
1222                         args->pte_pfn = args->pmd_pfn;
1223                         return 0;
1224                 }
1225         }
1226
1227         page = alloc_pages(GFP_KERNEL, 0);
1228         if (page)
1229                 args->pte_pfn = page_to_pfn(page);
1230
1231         return 0;
1232
1233 error:
1234         destroy_args(args);
1235         return ret;
1236 }
1237
1238 static int __init debug_vm_pgtable(void)
1239 {
1240         struct pgtable_debug_args args;
1241         spinlock_t *ptl = NULL;
1242         int idx, ret;
1243
1244         pr_info("Validating architecture page table helpers\n");
1245         ret = init_args(&args);
1246         if (ret)
1247                 return ret;
1248
1249         /*
1250          * Iterate over the protection_map[] to make sure that all
1251          * the basic page table transformation validations just hold
1252          * true irrespective of the starting protection value for a
1253          * given page table entry.
1254          */
1255         for (idx = 0; idx < ARRAY_SIZE(protection_map); idx++) {
1256                 pte_basic_tests(&args, idx);
1257                 pmd_basic_tests(&args, idx);
1258                 pud_basic_tests(&args, idx);
1259         }
1260
1261         /*
1262          * Both P4D and PGD level tests are very basic which do not
1263          * involve creating page table entries from the protection
1264          * value and the given pfn. Hence just keep them out from
1265          * the above iteration for now to save some test execution
1266          * time.
1267          */
1268         p4d_basic_tests(&args);
1269         pgd_basic_tests(&args);
1270
1271         pmd_leaf_tests(&args);
1272         pud_leaf_tests(&args);
1273
1274         pte_savedwrite_tests(&args);
1275         pmd_savedwrite_tests(&args);
1276
1277         pte_special_tests(&args);
1278         pte_protnone_tests(&args);
1279         pmd_protnone_tests(&args);
1280
1281         pte_devmap_tests(&args);
1282         pmd_devmap_tests(&args);
1283         pud_devmap_tests(&args);
1284
1285         pte_soft_dirty_tests(&args);
1286         pmd_soft_dirty_tests(&args);
1287         pte_swap_soft_dirty_tests(&args);
1288         pmd_swap_soft_dirty_tests(&args);
1289
1290         pte_swap_tests(&args);
1291         pmd_swap_tests(&args);
1292
1293         swap_migration_tests(&args);
1294
1295         pmd_thp_tests(&args);
1296         pud_thp_tests(&args);
1297
1298         hugetlb_basic_tests(&args);
1299
1300         /*
1301          * Page table modifying tests. They need to hold
1302          * proper page table lock.
1303          */
1304
1305         args.ptep = pte_offset_map_lock(args.mm, args.pmdp, args.vaddr, &ptl);
1306         pte_clear_tests(&args);
1307         pte_advanced_tests(&args);
1308         pte_unmap_unlock(args.ptep, ptl);
1309
1310         ptl = pmd_lock(args.mm, args.pmdp);
1311         pmd_clear_tests(&args);
1312         pmd_advanced_tests(&args);
1313         pmd_huge_tests(&args);
1314         pmd_populate_tests(&args);
1315         spin_unlock(ptl);
1316
1317         ptl = pud_lock(args.mm, args.pudp);
1318         pud_clear_tests(&args);
1319         pud_advanced_tests(&args);
1320         pud_huge_tests(&args);
1321         pud_populate_tests(&args);
1322         spin_unlock(ptl);
1323
1324         spin_lock(&(args.mm->page_table_lock));
1325         p4d_clear_tests(&args);
1326         pgd_clear_tests(&args);
1327         p4d_populate_tests(&args);
1328         pgd_populate_tests(&args);
1329         spin_unlock(&(args.mm->page_table_lock));
1330
1331         destroy_args(&args);
1332         return 0;
1333 }
1334 late_initcall(debug_vm_pgtable);