1 // SPDX-License-Identifier: GPL-2.0-only
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.
7 * Copyright (C) 2019 ARM Ltd.
9 * Author: Anshuman Khandual <anshuman.khandual@arm.com>
11 #define pr_fmt(fmt) "debug_vm_pgtable: [%-25s]: " fmt, __func__
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>
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>
32 #include <asm/pgalloc.h>
33 #include <asm/tlbflush.h>
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.
41 #define VMFLAGS (VM_READ|VM_WRITE|VM_EXEC)
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.
51 #define S390_SKIP_MASK GENMASK(3, 0)
52 #if __BITS_PER_LONG == 64
53 #define PPC64_SKIP_MASK GENMASK(62, 62)
55 #define PPC64_SKIP_MASK 0x0
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)
61 static void __init pte_basic_tests(unsigned long pfn, int idx)
63 pgprot_t prot = protection_map[idx];
64 pte_t pte = pfn_pte(pfn, prot);
65 unsigned long val = idx, *ptr = &val;
67 pr_debug("Validating PTE basic (%pGv)\n", ptr);
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.
76 WARN_ON(pte_dirty(pte_wrprotect(pte)));
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))));
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,
94 pte_t pte = pfn_pte(pfn, prot);
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
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));
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));
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));
132 ptep_get_and_clear_full(mm, vaddr, ptep, 1);
135 static void __init pte_savedwrite_tests(unsigned long pfn, pgprot_t prot)
137 pte_t pte = pfn_pte(pfn, prot);
139 if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
142 pr_debug("Validating PTE saved write\n");
143 WARN_ON(!pte_savedwrite(pte_mk_savedwrite(pte_clear_savedwrite(pte))));
144 WARN_ON(pte_savedwrite(pte_clear_savedwrite(pte_mk_savedwrite(pte))));
147 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
148 static void __init pmd_basic_tests(unsigned long pfn, int idx)
150 pgprot_t prot = protection_map[idx];
151 unsigned long val = idx, *ptr = &val;
154 if (!has_transparent_hugepage())
157 pr_debug("Validating PMD basic (%pGv)\n", ptr);
158 pmd = pfn_pmd(pfn, prot);
161 * This test needs to be executed after the given page table entry
162 * is created with pfn_pmd() to make sure that protection_map[idx]
163 * does not have the dirty bit enabled from the beginning. This is
164 * important for platforms like arm64 where (!PTE_RDONLY) indicate
165 * dirty bit being set.
167 WARN_ON(pmd_dirty(pmd_wrprotect(pmd)));
170 WARN_ON(!pmd_same(pmd, pmd));
171 WARN_ON(!pmd_young(pmd_mkyoung(pmd_mkold(pmd))));
172 WARN_ON(!pmd_dirty(pmd_mkdirty(pmd_mkclean(pmd))));
173 WARN_ON(!pmd_write(pmd_mkwrite(pmd_wrprotect(pmd))));
174 WARN_ON(pmd_young(pmd_mkold(pmd_mkyoung(pmd))));
175 WARN_ON(pmd_dirty(pmd_mkclean(pmd_mkdirty(pmd))));
176 WARN_ON(pmd_write(pmd_wrprotect(pmd_mkwrite(pmd))));
177 WARN_ON(pmd_dirty(pmd_wrprotect(pmd_mkclean(pmd))));
178 WARN_ON(!pmd_dirty(pmd_wrprotect(pmd_mkdirty(pmd))));
180 * A huge page does not point to next level page table
181 * entry. Hence this must qualify as pmd_bad().
183 WARN_ON(!pmd_bad(pmd_mkhuge(pmd)));
186 static void __init pmd_advanced_tests(struct mm_struct *mm,
187 struct vm_area_struct *vma, pmd_t *pmdp,
188 unsigned long pfn, unsigned long vaddr,
189 pgprot_t prot, pgtable_t pgtable)
193 if (!has_transparent_hugepage())
196 pr_debug("Validating PMD advanced\n");
197 /* Align the address wrt HPAGE_PMD_SIZE */
198 vaddr &= HPAGE_PMD_MASK;
200 pgtable_trans_huge_deposit(mm, pmdp, pgtable);
202 pmd = pfn_pmd(pfn, prot);
203 set_pmd_at(mm, vaddr, pmdp, pmd);
204 pmdp_set_wrprotect(mm, vaddr, pmdp);
205 pmd = READ_ONCE(*pmdp);
206 WARN_ON(pmd_write(pmd));
207 pmdp_huge_get_and_clear(mm, vaddr, pmdp);
208 pmd = READ_ONCE(*pmdp);
209 WARN_ON(!pmd_none(pmd));
211 pmd = pfn_pmd(pfn, prot);
212 pmd = pmd_wrprotect(pmd);
213 pmd = pmd_mkclean(pmd);
214 set_pmd_at(mm, vaddr, pmdp, pmd);
215 pmd = pmd_mkwrite(pmd);
216 pmd = pmd_mkdirty(pmd);
217 pmdp_set_access_flags(vma, vaddr, pmdp, pmd, 1);
218 pmd = READ_ONCE(*pmdp);
219 WARN_ON(!(pmd_write(pmd) && pmd_dirty(pmd)));
220 pmdp_huge_get_and_clear_full(vma, vaddr, pmdp, 1);
221 pmd = READ_ONCE(*pmdp);
222 WARN_ON(!pmd_none(pmd));
224 pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
225 pmd = pmd_mkyoung(pmd);
226 set_pmd_at(mm, vaddr, pmdp, pmd);
227 pmdp_test_and_clear_young(vma, vaddr, pmdp);
228 pmd = READ_ONCE(*pmdp);
229 WARN_ON(pmd_young(pmd));
231 /* Clear the pte entries */
232 pmdp_huge_get_and_clear(mm, vaddr, pmdp);
233 pgtable = pgtable_trans_huge_withdraw(mm, pmdp);
236 static void __init pmd_leaf_tests(unsigned long pfn, pgprot_t prot)
240 if (!has_transparent_hugepage())
243 pr_debug("Validating PMD leaf\n");
244 pmd = pfn_pmd(pfn, prot);
247 * PMD based THP is a leaf entry.
249 pmd = pmd_mkhuge(pmd);
250 WARN_ON(!pmd_leaf(pmd));
253 #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
254 static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot)
258 if (!arch_ioremap_pmd_supported())
261 pr_debug("Validating PMD huge\n");
263 * X86 defined pmd_set_huge() verifies that the given
264 * PMD is not a populated non-leaf entry.
266 WRITE_ONCE(*pmdp, __pmd(0));
267 WARN_ON(!pmd_set_huge(pmdp, __pfn_to_phys(pfn), prot));
268 WARN_ON(!pmd_clear_huge(pmdp));
269 pmd = READ_ONCE(*pmdp);
270 WARN_ON(!pmd_none(pmd));
272 #else /* CONFIG_HAVE_ARCH_HUGE_VMAP */
273 static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot) { }
274 #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
276 static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot)
280 if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
283 if (!has_transparent_hugepage())
286 pr_debug("Validating PMD saved write\n");
287 pmd = pfn_pmd(pfn, prot);
288 WARN_ON(!pmd_savedwrite(pmd_mk_savedwrite(pmd_clear_savedwrite(pmd))));
289 WARN_ON(pmd_savedwrite(pmd_clear_savedwrite(pmd_mk_savedwrite(pmd))));
292 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
293 static void __init pud_basic_tests(struct mm_struct *mm, unsigned long pfn, int idx)
295 pgprot_t prot = protection_map[idx];
296 unsigned long val = idx, *ptr = &val;
299 if (!has_transparent_hugepage())
302 pr_debug("Validating PUD basic (%pGv)\n", ptr);
303 pud = pfn_pud(pfn, prot);
306 * This test needs to be executed after the given page table entry
307 * is created with pfn_pud() to make sure that protection_map[idx]
308 * does not have the dirty bit enabled from the beginning. This is
309 * important for platforms like arm64 where (!PTE_RDONLY) indicate
310 * dirty bit being set.
312 WARN_ON(pud_dirty(pud_wrprotect(pud)));
314 WARN_ON(!pud_same(pud, pud));
315 WARN_ON(!pud_young(pud_mkyoung(pud_mkold(pud))));
316 WARN_ON(!pud_dirty(pud_mkdirty(pud_mkclean(pud))));
317 WARN_ON(pud_dirty(pud_mkclean(pud_mkdirty(pud))));
318 WARN_ON(!pud_write(pud_mkwrite(pud_wrprotect(pud))));
319 WARN_ON(pud_write(pud_wrprotect(pud_mkwrite(pud))));
320 WARN_ON(pud_young(pud_mkold(pud_mkyoung(pud))));
321 WARN_ON(pud_dirty(pud_wrprotect(pud_mkclean(pud))));
322 WARN_ON(!pud_dirty(pud_wrprotect(pud_mkdirty(pud))));
324 if (mm_pmd_folded(mm))
328 * A huge page does not point to next level page table
329 * entry. Hence this must qualify as pud_bad().
331 WARN_ON(!pud_bad(pud_mkhuge(pud)));
334 static void __init pud_advanced_tests(struct mm_struct *mm,
335 struct vm_area_struct *vma, pud_t *pudp,
336 unsigned long pfn, unsigned long vaddr,
341 if (!has_transparent_hugepage())
344 pr_debug("Validating PUD advanced\n");
345 /* Align the address wrt HPAGE_PUD_SIZE */
346 vaddr &= HPAGE_PUD_MASK;
348 pud = pfn_pud(pfn, prot);
349 set_pud_at(mm, vaddr, pudp, pud);
350 pudp_set_wrprotect(mm, vaddr, pudp);
351 pud = READ_ONCE(*pudp);
352 WARN_ON(pud_write(pud));
354 #ifndef __PAGETABLE_PMD_FOLDED
355 pudp_huge_get_and_clear(mm, vaddr, pudp);
356 pud = READ_ONCE(*pudp);
357 WARN_ON(!pud_none(pud));
358 #endif /* __PAGETABLE_PMD_FOLDED */
359 pud = pfn_pud(pfn, prot);
360 pud = pud_wrprotect(pud);
361 pud = pud_mkclean(pud);
362 set_pud_at(mm, vaddr, pudp, pud);
363 pud = pud_mkwrite(pud);
364 pud = pud_mkdirty(pud);
365 pudp_set_access_flags(vma, vaddr, pudp, pud, 1);
366 pud = READ_ONCE(*pudp);
367 WARN_ON(!(pud_write(pud) && pud_dirty(pud)));
369 #ifndef __PAGETABLE_PMD_FOLDED
370 pudp_huge_get_and_clear_full(mm, vaddr, pudp, 1);
371 pud = READ_ONCE(*pudp);
372 WARN_ON(!pud_none(pud));
373 #endif /* __PAGETABLE_PMD_FOLDED */
375 pud = pfn_pud(pfn, prot);
376 pud = pud_mkyoung(pud);
377 set_pud_at(mm, vaddr, pudp, pud);
378 pudp_test_and_clear_young(vma, vaddr, pudp);
379 pud = READ_ONCE(*pudp);
380 WARN_ON(pud_young(pud));
382 pudp_huge_get_and_clear(mm, vaddr, pudp);
385 static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot)
389 if (!has_transparent_hugepage())
392 pr_debug("Validating PUD leaf\n");
393 pud = pfn_pud(pfn, prot);
395 * PUD based THP is a leaf entry.
397 pud = pud_mkhuge(pud);
398 WARN_ON(!pud_leaf(pud));
401 #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
402 static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot)
406 if (!arch_ioremap_pud_supported())
409 pr_debug("Validating PUD huge\n");
411 * X86 defined pud_set_huge() verifies that the given
412 * PUD is not a populated non-leaf entry.
414 WRITE_ONCE(*pudp, __pud(0));
415 WARN_ON(!pud_set_huge(pudp, __pfn_to_phys(pfn), prot));
416 WARN_ON(!pud_clear_huge(pudp));
417 pud = READ_ONCE(*pudp);
418 WARN_ON(!pud_none(pud));
420 #else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
421 static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot) { }
422 #endif /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
424 #else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
425 static void __init pud_basic_tests(struct mm_struct *mm, unsigned long pfn, int idx) { }
426 static void __init pud_advanced_tests(struct mm_struct *mm,
427 struct vm_area_struct *vma, pud_t *pudp,
428 unsigned long pfn, unsigned long vaddr,
432 static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot) { }
433 static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot)
436 #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
437 #else /* !CONFIG_TRANSPARENT_HUGEPAGE */
438 static void __init pmd_basic_tests(unsigned long pfn, int idx) { }
439 static void __init pud_basic_tests(struct mm_struct *mm, unsigned long pfn, int idx) { }
440 static void __init pmd_advanced_tests(struct mm_struct *mm,
441 struct vm_area_struct *vma, pmd_t *pmdp,
442 unsigned long pfn, unsigned long vaddr,
443 pgprot_t prot, pgtable_t pgtable)
446 static void __init pud_advanced_tests(struct mm_struct *mm,
447 struct vm_area_struct *vma, pud_t *pudp,
448 unsigned long pfn, unsigned long vaddr,
452 static void __init pmd_leaf_tests(unsigned long pfn, pgprot_t prot) { }
453 static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot) { }
454 static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot)
457 static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot)
460 static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot) { }
461 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
463 static void __init p4d_basic_tests(unsigned long pfn, pgprot_t prot)
467 pr_debug("Validating P4D basic\n");
468 memset(&p4d, RANDOM_NZVALUE, sizeof(p4d_t));
469 WARN_ON(!p4d_same(p4d, p4d));
472 static void __init pgd_basic_tests(unsigned long pfn, pgprot_t prot)
476 pr_debug("Validating PGD basic\n");
477 memset(&pgd, RANDOM_NZVALUE, sizeof(pgd_t));
478 WARN_ON(!pgd_same(pgd, pgd));
481 #ifndef __PAGETABLE_PUD_FOLDED
482 static void __init pud_clear_tests(struct mm_struct *mm, pud_t *pudp)
484 pud_t pud = READ_ONCE(*pudp);
486 if (mm_pmd_folded(mm))
489 pr_debug("Validating PUD clear\n");
490 pud = __pud(pud_val(pud) | RANDOM_ORVALUE);
491 WRITE_ONCE(*pudp, pud);
493 pud = READ_ONCE(*pudp);
494 WARN_ON(!pud_none(pud));
497 static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp,
502 if (mm_pmd_folded(mm))
505 pr_debug("Validating PUD populate\n");
507 * This entry points to next level page table page.
508 * Hence this must not qualify as pud_bad().
510 pud_populate(mm, pudp, pmdp);
511 pud = READ_ONCE(*pudp);
512 WARN_ON(pud_bad(pud));
514 #else /* !__PAGETABLE_PUD_FOLDED */
515 static void __init pud_clear_tests(struct mm_struct *mm, pud_t *pudp) { }
516 static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp,
520 #endif /* PAGETABLE_PUD_FOLDED */
522 #ifndef __PAGETABLE_P4D_FOLDED
523 static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp)
525 p4d_t p4d = READ_ONCE(*p4dp);
527 if (mm_pud_folded(mm))
530 pr_debug("Validating P4D clear\n");
531 p4d = __p4d(p4d_val(p4d) | RANDOM_ORVALUE);
532 WRITE_ONCE(*p4dp, p4d);
534 p4d = READ_ONCE(*p4dp);
535 WARN_ON(!p4d_none(p4d));
538 static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp,
543 if (mm_pud_folded(mm))
546 pr_debug("Validating P4D populate\n");
548 * This entry points to next level page table page.
549 * Hence this must not qualify as p4d_bad().
553 p4d_populate(mm, p4dp, pudp);
554 p4d = READ_ONCE(*p4dp);
555 WARN_ON(p4d_bad(p4d));
558 static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp)
560 pgd_t pgd = READ_ONCE(*pgdp);
562 if (mm_p4d_folded(mm))
565 pr_debug("Validating PGD clear\n");
566 pgd = __pgd(pgd_val(pgd) | RANDOM_ORVALUE);
567 WRITE_ONCE(*pgdp, pgd);
569 pgd = READ_ONCE(*pgdp);
570 WARN_ON(!pgd_none(pgd));
573 static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
578 if (mm_p4d_folded(mm))
581 pr_debug("Validating PGD populate\n");
583 * This entry points to next level page table page.
584 * Hence this must not qualify as pgd_bad().
588 pgd_populate(mm, pgdp, p4dp);
589 pgd = READ_ONCE(*pgdp);
590 WARN_ON(pgd_bad(pgd));
592 #else /* !__PAGETABLE_P4D_FOLDED */
593 static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp) { }
594 static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp) { }
595 static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp,
599 static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
603 #endif /* PAGETABLE_P4D_FOLDED */
605 static void __init pte_clear_tests(struct mm_struct *mm, pte_t *ptep,
606 unsigned long pfn, unsigned long vaddr,
609 pte_t pte = pfn_pte(pfn, prot);
611 pr_debug("Validating PTE clear\n");
613 pte = __pte(pte_val(pte) | RANDOM_ORVALUE);
615 set_pte_at(mm, vaddr, ptep, pte);
617 pte_clear(mm, vaddr, ptep);
618 pte = ptep_get(ptep);
619 WARN_ON(!pte_none(pte));
622 static void __init pmd_clear_tests(struct mm_struct *mm, pmd_t *pmdp)
624 pmd_t pmd = READ_ONCE(*pmdp);
626 pr_debug("Validating PMD clear\n");
627 pmd = __pmd(pmd_val(pmd) | RANDOM_ORVALUE);
628 WRITE_ONCE(*pmdp, pmd);
630 pmd = READ_ONCE(*pmdp);
631 WARN_ON(!pmd_none(pmd));
634 static void __init pmd_populate_tests(struct mm_struct *mm, pmd_t *pmdp,
639 pr_debug("Validating PMD populate\n");
641 * This entry points to next level page table page.
642 * Hence this must not qualify as pmd_bad().
644 pmd_populate(mm, pmdp, pgtable);
645 pmd = READ_ONCE(*pmdp);
646 WARN_ON(pmd_bad(pmd));
649 static void __init pte_special_tests(unsigned long pfn, pgprot_t prot)
651 pte_t pte = pfn_pte(pfn, prot);
653 if (!IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL))
656 pr_debug("Validating PTE special\n");
657 WARN_ON(!pte_special(pte_mkspecial(pte)));
660 static void __init pte_protnone_tests(unsigned long pfn, pgprot_t prot)
662 pte_t pte = pfn_pte(pfn, prot);
664 if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
667 pr_debug("Validating PTE protnone\n");
668 WARN_ON(!pte_protnone(pte));
669 WARN_ON(!pte_present(pte));
672 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
673 static void __init pmd_protnone_tests(unsigned long pfn, pgprot_t prot)
677 if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
680 if (!has_transparent_hugepage())
683 pr_debug("Validating PMD protnone\n");
684 pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
685 WARN_ON(!pmd_protnone(pmd));
686 WARN_ON(!pmd_present(pmd));
688 #else /* !CONFIG_TRANSPARENT_HUGEPAGE */
689 static void __init pmd_protnone_tests(unsigned long pfn, pgprot_t prot) { }
690 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
692 #ifdef CONFIG_ARCH_HAS_PTE_DEVMAP
693 static void __init pte_devmap_tests(unsigned long pfn, pgprot_t prot)
695 pte_t pte = pfn_pte(pfn, prot);
697 pr_debug("Validating PTE devmap\n");
698 WARN_ON(!pte_devmap(pte_mkdevmap(pte)));
701 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
702 static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot)
706 if (!has_transparent_hugepage())
709 pr_debug("Validating PMD devmap\n");
710 pmd = pfn_pmd(pfn, prot);
711 WARN_ON(!pmd_devmap(pmd_mkdevmap(pmd)));
714 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
715 static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot)
719 if (!has_transparent_hugepage())
722 pr_debug("Validating PUD devmap\n");
723 pud = pfn_pud(pfn, prot);
724 WARN_ON(!pud_devmap(pud_mkdevmap(pud)));
726 #else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
727 static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) { }
728 #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
729 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
730 static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot) { }
731 static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) { }
732 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
734 static void __init pte_devmap_tests(unsigned long pfn, pgprot_t prot) { }
735 static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot) { }
736 static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) { }
737 #endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */
739 static void __init pte_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
741 pte_t pte = pfn_pte(pfn, prot);
743 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
746 pr_debug("Validating PTE soft dirty\n");
747 WARN_ON(!pte_soft_dirty(pte_mksoft_dirty(pte)));
748 WARN_ON(pte_soft_dirty(pte_clear_soft_dirty(pte)));
751 static void __init pte_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
753 pte_t pte = pfn_pte(pfn, prot);
755 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
758 pr_debug("Validating PTE swap soft dirty\n");
759 WARN_ON(!pte_swp_soft_dirty(pte_swp_mksoft_dirty(pte)));
760 WARN_ON(pte_swp_soft_dirty(pte_swp_clear_soft_dirty(pte)));
763 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
764 static void __init pmd_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
768 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
771 if (!has_transparent_hugepage())
774 pr_debug("Validating PMD soft dirty\n");
775 pmd = pfn_pmd(pfn, prot);
776 WARN_ON(!pmd_soft_dirty(pmd_mksoft_dirty(pmd)));
777 WARN_ON(pmd_soft_dirty(pmd_clear_soft_dirty(pmd)));
780 static void __init pmd_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
784 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY) ||
785 !IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION))
788 if (!has_transparent_hugepage())
791 pr_debug("Validating PMD swap soft dirty\n");
792 pmd = pfn_pmd(pfn, prot);
793 WARN_ON(!pmd_swp_soft_dirty(pmd_swp_mksoft_dirty(pmd)));
794 WARN_ON(pmd_swp_soft_dirty(pmd_swp_clear_soft_dirty(pmd)));
796 #else /* !CONFIG_ARCH_HAS_PTE_DEVMAP */
797 static void __init pmd_soft_dirty_tests(unsigned long pfn, pgprot_t prot) { }
798 static void __init pmd_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
801 #endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */
803 static void __init pte_swap_tests(unsigned long pfn, pgprot_t prot)
808 pr_debug("Validating PTE swap\n");
809 pte = pfn_pte(pfn, prot);
810 swp = __pte_to_swp_entry(pte);
811 pte = __swp_entry_to_pte(swp);
812 WARN_ON(pfn != pte_pfn(pte));
815 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
816 static void __init pmd_swap_tests(unsigned long pfn, pgprot_t prot)
821 if (!has_transparent_hugepage())
824 pr_debug("Validating PMD swap\n");
825 pmd = pfn_pmd(pfn, prot);
826 swp = __pmd_to_swp_entry(pmd);
827 pmd = __swp_entry_to_pmd(swp);
828 WARN_ON(pfn != pmd_pfn(pmd));
830 #else /* !CONFIG_ARCH_ENABLE_THP_MIGRATION */
831 static void __init pmd_swap_tests(unsigned long pfn, pgprot_t prot) { }
832 #endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
834 static void __init swap_migration_tests(void)
839 if (!IS_ENABLED(CONFIG_MIGRATION))
842 pr_debug("Validating swap migration\n");
844 * swap_migration_tests() requires a dedicated page as it needs to
845 * be locked before creating a migration entry from it. Locking the
846 * page that actually maps kernel text ('start_kernel') can be real
847 * problematic. Lets allocate a dedicated page explicitly for this
848 * purpose that will be freed subsequently.
850 page = alloc_page(GFP_KERNEL);
852 pr_err("page allocation failed\n");
857 * make_migration_entry() expects given page to be
858 * locked, otherwise it stumbles upon a BUG_ON().
860 __SetPageLocked(page);
861 swp = make_migration_entry(page, 1);
862 WARN_ON(!is_migration_entry(swp));
863 WARN_ON(!is_write_migration_entry(swp));
865 make_migration_entry_read(&swp);
866 WARN_ON(!is_migration_entry(swp));
867 WARN_ON(is_write_migration_entry(swp));
869 swp = make_migration_entry(page, 0);
870 WARN_ON(!is_migration_entry(swp));
871 WARN_ON(is_write_migration_entry(swp));
872 __ClearPageLocked(page);
876 #ifdef CONFIG_HUGETLB_PAGE
877 static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot)
882 pr_debug("Validating HugeTLB basic\n");
884 * Accessing the page associated with the pfn is safe here,
885 * as it was previously derived from a real kernel symbol.
887 page = pfn_to_page(pfn);
888 pte = mk_huge_pte(page, prot);
890 WARN_ON(!huge_pte_dirty(huge_pte_mkdirty(pte)));
891 WARN_ON(!huge_pte_write(huge_pte_mkwrite(huge_pte_wrprotect(pte))));
892 WARN_ON(huge_pte_write(huge_pte_wrprotect(huge_pte_mkwrite(pte))));
894 #ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB
895 pte = pfn_pte(pfn, prot);
897 WARN_ON(!pte_huge(pte_mkhuge(pte)));
898 #endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */
900 #else /* !CONFIG_HUGETLB_PAGE */
901 static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot) { }
902 #endif /* CONFIG_HUGETLB_PAGE */
904 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
905 static void __init pmd_thp_tests(unsigned long pfn, pgprot_t prot)
909 if (!has_transparent_hugepage())
912 pr_debug("Validating PMD based THP\n");
914 * pmd_trans_huge() and pmd_present() must return positive after
915 * MMU invalidation with pmd_mkinvalid(). This behavior is an
916 * optimization for transparent huge page. pmd_trans_huge() must
917 * be true if pmd_page() returns a valid THP to avoid taking the
918 * pmd_lock when others walk over non transhuge pmds (i.e. there
919 * are no THP allocated). Especially when splitting a THP and
920 * removing the present bit from the pmd, pmd_trans_huge() still
921 * needs to return true. pmd_present() should be true whenever
922 * pmd_trans_huge() returns true.
924 pmd = pfn_pmd(pfn, prot);
925 WARN_ON(!pmd_trans_huge(pmd_mkhuge(pmd)));
927 #ifndef __HAVE_ARCH_PMDP_INVALIDATE
928 WARN_ON(!pmd_trans_huge(pmd_mkinvalid(pmd_mkhuge(pmd))));
929 WARN_ON(!pmd_present(pmd_mkinvalid(pmd_mkhuge(pmd))));
930 #endif /* __HAVE_ARCH_PMDP_INVALIDATE */
933 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
934 static void __init pud_thp_tests(unsigned long pfn, pgprot_t prot)
938 if (!has_transparent_hugepage())
941 pr_debug("Validating PUD based THP\n");
942 pud = pfn_pud(pfn, prot);
943 WARN_ON(!pud_trans_huge(pud_mkhuge(pud)));
946 * pud_mkinvalid() has been dropped for now. Enable back
947 * these tests when it comes back with a modified pud_present().
949 * WARN_ON(!pud_trans_huge(pud_mkinvalid(pud_mkhuge(pud))));
950 * WARN_ON(!pud_present(pud_mkinvalid(pud_mkhuge(pud))));
953 #else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
954 static void __init pud_thp_tests(unsigned long pfn, pgprot_t prot) { }
955 #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
956 #else /* !CONFIG_TRANSPARENT_HUGEPAGE */
957 static void __init pmd_thp_tests(unsigned long pfn, pgprot_t prot) { }
958 static void __init pud_thp_tests(unsigned long pfn, pgprot_t prot) { }
959 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
961 static unsigned long __init get_random_vaddr(void)
963 unsigned long random_vaddr, random_pages, total_user_pages;
965 total_user_pages = (TASK_SIZE - FIRST_USER_ADDRESS) / PAGE_SIZE;
967 random_pages = get_random_long() % total_user_pages;
968 random_vaddr = FIRST_USER_ADDRESS + random_pages * PAGE_SIZE;
973 static int __init debug_vm_pgtable(void)
975 struct vm_area_struct *vma;
976 struct mm_struct *mm;
978 p4d_t *p4dp, *saved_p4dp;
979 pud_t *pudp, *saved_pudp;
980 pmd_t *pmdp, *saved_pmdp, pmd;
982 pgtable_t saved_ptep;
983 pgprot_t prot, protnone;
985 unsigned long vaddr, pte_aligned, pmd_aligned;
986 unsigned long pud_aligned, p4d_aligned, pgd_aligned;
987 spinlock_t *ptl = NULL;
990 pr_info("Validating architecture page table helpers\n");
991 prot = vm_get_page_prot(VMFLAGS);
992 vaddr = get_random_vaddr();
995 pr_err("mm_struct allocation failed\n");
1000 * __P000 (or even __S000) will help create page table entries with
1001 * PROT_NONE permission as required for pxx_protnone_tests().
1005 vma = vm_area_alloc(mm);
1007 pr_err("vma allocation failed\n");
1012 * PFN for mapping at PTE level is determined from a standard kernel
1013 * text symbol. But pfns for higher page table levels are derived by
1014 * masking lower bits of this real pfn. These derived pfns might not
1015 * exist on the platform but that does not really matter as pfn_pxx()
1016 * helpers will still create appropriate entries for the test. This
1017 * helps avoid large memory block allocations to be used for mapping
1018 * at higher page table levels.
1020 paddr = __pa_symbol(&start_kernel);
1022 pte_aligned = (paddr & PAGE_MASK) >> PAGE_SHIFT;
1023 pmd_aligned = (paddr & PMD_MASK) >> PAGE_SHIFT;
1024 pud_aligned = (paddr & PUD_MASK) >> PAGE_SHIFT;
1025 p4d_aligned = (paddr & P4D_MASK) >> PAGE_SHIFT;
1026 pgd_aligned = (paddr & PGDIR_MASK) >> PAGE_SHIFT;
1027 WARN_ON(!pfn_valid(pte_aligned));
1029 pgdp = pgd_offset(mm, vaddr);
1030 p4dp = p4d_alloc(mm, pgdp, vaddr);
1031 pudp = pud_alloc(mm, p4dp, vaddr);
1032 pmdp = pmd_alloc(mm, pudp, vaddr);
1034 * Allocate pgtable_t
1036 if (pte_alloc(mm, pmdp)) {
1037 pr_err("pgtable allocation failed\n");
1042 * Save all the page table page addresses as the page table
1043 * entries will be used for testing with random or garbage
1044 * values. These saved addresses will be used for freeing
1047 pmd = READ_ONCE(*pmdp);
1048 saved_p4dp = p4d_offset(pgdp, 0UL);
1049 saved_pudp = pud_offset(p4dp, 0UL);
1050 saved_pmdp = pmd_offset(pudp, 0UL);
1051 saved_ptep = pmd_pgtable(pmd);
1054 * Iterate over the protection_map[] to make sure that all
1055 * the basic page table transformation validations just hold
1056 * true irrespective of the starting protection value for a
1057 * given page table entry.
1059 for (idx = 0; idx < ARRAY_SIZE(protection_map); idx++) {
1060 pte_basic_tests(pte_aligned, idx);
1061 pmd_basic_tests(pmd_aligned, idx);
1062 pud_basic_tests(mm, pud_aligned, idx);
1066 * Both P4D and PGD level tests are very basic which do not
1067 * involve creating page table entries from the protection
1068 * value and the given pfn. Hence just keep them out from
1069 * the above iteration for now to save some test execution
1072 p4d_basic_tests(p4d_aligned, prot);
1073 pgd_basic_tests(pgd_aligned, prot);
1075 pmd_leaf_tests(pmd_aligned, prot);
1076 pud_leaf_tests(pud_aligned, prot);
1078 pte_savedwrite_tests(pte_aligned, protnone);
1079 pmd_savedwrite_tests(pmd_aligned, protnone);
1081 pte_special_tests(pte_aligned, prot);
1082 pte_protnone_tests(pte_aligned, protnone);
1083 pmd_protnone_tests(pmd_aligned, protnone);
1085 pte_devmap_tests(pte_aligned, prot);
1086 pmd_devmap_tests(pmd_aligned, prot);
1087 pud_devmap_tests(pud_aligned, prot);
1089 pte_soft_dirty_tests(pte_aligned, prot);
1090 pmd_soft_dirty_tests(pmd_aligned, prot);
1091 pte_swap_soft_dirty_tests(pte_aligned, prot);
1092 pmd_swap_soft_dirty_tests(pmd_aligned, prot);
1094 pte_swap_tests(pte_aligned, prot);
1095 pmd_swap_tests(pmd_aligned, prot);
1097 swap_migration_tests();
1099 pmd_thp_tests(pmd_aligned, prot);
1100 pud_thp_tests(pud_aligned, prot);
1102 hugetlb_basic_tests(pte_aligned, prot);
1105 * Page table modifying tests. They need to hold
1106 * proper page table lock.
1109 ptep = pte_offset_map_lock(mm, pmdp, vaddr, &ptl);
1110 pte_clear_tests(mm, ptep, pte_aligned, vaddr, prot);
1111 pte_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot);
1112 pte_unmap_unlock(ptep, ptl);
1114 ptl = pmd_lock(mm, pmdp);
1115 pmd_clear_tests(mm, pmdp);
1116 pmd_advanced_tests(mm, vma, pmdp, pmd_aligned, vaddr, prot, saved_ptep);
1117 pmd_huge_tests(pmdp, pmd_aligned, prot);
1118 pmd_populate_tests(mm, pmdp, saved_ptep);
1121 ptl = pud_lock(mm, pudp);
1122 pud_clear_tests(mm, pudp);
1123 pud_advanced_tests(mm, vma, pudp, pud_aligned, vaddr, prot);
1124 pud_huge_tests(pudp, pud_aligned, prot);
1125 pud_populate_tests(mm, pudp, saved_pmdp);
1128 spin_lock(&mm->page_table_lock);
1129 p4d_clear_tests(mm, p4dp);
1130 pgd_clear_tests(mm, pgdp);
1131 p4d_populate_tests(mm, p4dp, saved_pudp);
1132 pgd_populate_tests(mm, pgdp, saved_p4dp);
1133 spin_unlock(&mm->page_table_lock);
1135 p4d_free(mm, saved_p4dp);
1136 pud_free(mm, saved_pudp);
1137 pmd_free(mm, saved_pmdp);
1138 pte_free(mm, saved_ptep);
1147 late_initcall(debug_vm_pgtable);