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, pgprot_t prot)
63 pte_t pte = pfn_pte(pfn, prot);
65 pr_debug("Validating PTE basic\n");
66 WARN_ON(!pte_same(pte, pte));
67 WARN_ON(!pte_young(pte_mkyoung(pte_mkold(pte))));
68 WARN_ON(!pte_dirty(pte_mkdirty(pte_mkclean(pte))));
69 WARN_ON(!pte_write(pte_mkwrite(pte_wrprotect(pte))));
70 WARN_ON(pte_young(pte_mkold(pte_mkyoung(pte))));
71 WARN_ON(pte_dirty(pte_mkclean(pte_mkdirty(pte))));
72 WARN_ON(pte_write(pte_wrprotect(pte_mkwrite(pte))));
75 static void __init pte_advanced_tests(struct mm_struct *mm,
76 struct vm_area_struct *vma, pte_t *ptep,
77 unsigned long pfn, unsigned long vaddr,
80 pte_t pte = pfn_pte(pfn, prot);
83 * Architectures optimize set_pte_at by avoiding TLB flush.
84 * This requires set_pte_at to be not used to update an
85 * existing pte entry. Clear pte before we do set_pte_at
88 pr_debug("Validating PTE advanced\n");
89 pte = pfn_pte(pfn, prot);
90 set_pte_at(mm, vaddr, ptep, pte);
91 ptep_set_wrprotect(mm, vaddr, ptep);
93 WARN_ON(pte_write(pte));
94 ptep_get_and_clear(mm, vaddr, ptep);
96 WARN_ON(!pte_none(pte));
98 pte = pfn_pte(pfn, prot);
99 pte = pte_wrprotect(pte);
100 pte = pte_mkclean(pte);
101 set_pte_at(mm, vaddr, ptep, pte);
102 pte = pte_mkwrite(pte);
103 pte = pte_mkdirty(pte);
104 ptep_set_access_flags(vma, vaddr, ptep, pte, 1);
105 pte = ptep_get(ptep);
106 WARN_ON(!(pte_write(pte) && pte_dirty(pte)));
107 ptep_get_and_clear_full(mm, vaddr, ptep, 1);
108 pte = ptep_get(ptep);
109 WARN_ON(!pte_none(pte));
111 pte = pfn_pte(pfn, prot);
112 pte = pte_mkyoung(pte);
113 set_pte_at(mm, vaddr, ptep, pte);
114 ptep_test_and_clear_young(vma, vaddr, ptep);
115 pte = ptep_get(ptep);
116 WARN_ON(pte_young(pte));
119 static void __init pte_savedwrite_tests(unsigned long pfn, pgprot_t prot)
121 pte_t pte = pfn_pte(pfn, prot);
123 if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
126 pr_debug("Validating PTE saved write\n");
127 WARN_ON(!pte_savedwrite(pte_mk_savedwrite(pte_clear_savedwrite(pte))));
128 WARN_ON(pte_savedwrite(pte_clear_savedwrite(pte_mk_savedwrite(pte))));
131 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
132 static void __init pmd_basic_tests(unsigned long pfn, pgprot_t prot)
134 pmd_t pmd = pfn_pmd(pfn, prot);
136 if (!has_transparent_hugepage())
139 pr_debug("Validating PMD basic\n");
140 WARN_ON(!pmd_same(pmd, pmd));
141 WARN_ON(!pmd_young(pmd_mkyoung(pmd_mkold(pmd))));
142 WARN_ON(!pmd_dirty(pmd_mkdirty(pmd_mkclean(pmd))));
143 WARN_ON(!pmd_write(pmd_mkwrite(pmd_wrprotect(pmd))));
144 WARN_ON(pmd_young(pmd_mkold(pmd_mkyoung(pmd))));
145 WARN_ON(pmd_dirty(pmd_mkclean(pmd_mkdirty(pmd))));
146 WARN_ON(pmd_write(pmd_wrprotect(pmd_mkwrite(pmd))));
148 * A huge page does not point to next level page table
149 * entry. Hence this must qualify as pmd_bad().
151 WARN_ON(!pmd_bad(pmd_mkhuge(pmd)));
154 static void __init pmd_advanced_tests(struct mm_struct *mm,
155 struct vm_area_struct *vma, pmd_t *pmdp,
156 unsigned long pfn, unsigned long vaddr,
157 pgprot_t prot, pgtable_t pgtable)
159 pmd_t pmd = pfn_pmd(pfn, prot);
161 if (!has_transparent_hugepage())
164 pr_debug("Validating PMD advanced\n");
165 /* Align the address wrt HPAGE_PMD_SIZE */
166 vaddr = (vaddr & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE;
168 pgtable_trans_huge_deposit(mm, pmdp, pgtable);
170 pmd = pfn_pmd(pfn, prot);
171 set_pmd_at(mm, vaddr, pmdp, pmd);
172 pmdp_set_wrprotect(mm, vaddr, pmdp);
173 pmd = READ_ONCE(*pmdp);
174 WARN_ON(pmd_write(pmd));
175 pmdp_huge_get_and_clear(mm, vaddr, pmdp);
176 pmd = READ_ONCE(*pmdp);
177 WARN_ON(!pmd_none(pmd));
179 pmd = pfn_pmd(pfn, prot);
180 pmd = pmd_wrprotect(pmd);
181 pmd = pmd_mkclean(pmd);
182 set_pmd_at(mm, vaddr, pmdp, pmd);
183 pmd = pmd_mkwrite(pmd);
184 pmd = pmd_mkdirty(pmd);
185 pmdp_set_access_flags(vma, vaddr, pmdp, pmd, 1);
186 pmd = READ_ONCE(*pmdp);
187 WARN_ON(!(pmd_write(pmd) && pmd_dirty(pmd)));
188 pmdp_huge_get_and_clear_full(vma, vaddr, pmdp, 1);
189 pmd = READ_ONCE(*pmdp);
190 WARN_ON(!pmd_none(pmd));
192 pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
193 pmd = pmd_mkyoung(pmd);
194 set_pmd_at(mm, vaddr, pmdp, pmd);
195 pmdp_test_and_clear_young(vma, vaddr, pmdp);
196 pmd = READ_ONCE(*pmdp);
197 WARN_ON(pmd_young(pmd));
199 /* Clear the pte entries */
200 pmdp_huge_get_and_clear(mm, vaddr, pmdp);
201 pgtable = pgtable_trans_huge_withdraw(mm, pmdp);
204 static void __init pmd_leaf_tests(unsigned long pfn, pgprot_t prot)
206 pmd_t pmd = pfn_pmd(pfn, prot);
208 pr_debug("Validating PMD leaf\n");
210 * PMD based THP is a leaf entry.
212 pmd = pmd_mkhuge(pmd);
213 WARN_ON(!pmd_leaf(pmd));
216 #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
217 static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot)
221 if (!arch_ioremap_pmd_supported())
224 pr_debug("Validating PMD huge\n");
226 * X86 defined pmd_set_huge() verifies that the given
227 * PMD is not a populated non-leaf entry.
229 WRITE_ONCE(*pmdp, __pmd(0));
230 WARN_ON(!pmd_set_huge(pmdp, __pfn_to_phys(pfn), prot));
231 WARN_ON(!pmd_clear_huge(pmdp));
232 pmd = READ_ONCE(*pmdp);
233 WARN_ON(!pmd_none(pmd));
235 #else /* CONFIG_HAVE_ARCH_HUGE_VMAP */
236 static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot) { }
237 #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
239 static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot)
241 pmd_t pmd = pfn_pmd(pfn, prot);
243 if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
246 pr_debug("Validating PMD saved write\n");
247 WARN_ON(!pmd_savedwrite(pmd_mk_savedwrite(pmd_clear_savedwrite(pmd))));
248 WARN_ON(pmd_savedwrite(pmd_clear_savedwrite(pmd_mk_savedwrite(pmd))));
251 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
252 static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot)
254 pud_t pud = pfn_pud(pfn, prot);
256 if (!has_transparent_hugepage())
259 pr_debug("Validating PUD basic\n");
260 WARN_ON(!pud_same(pud, pud));
261 WARN_ON(!pud_young(pud_mkyoung(pud_mkold(pud))));
262 WARN_ON(!pud_write(pud_mkwrite(pud_wrprotect(pud))));
263 WARN_ON(pud_write(pud_wrprotect(pud_mkwrite(pud))));
264 WARN_ON(pud_young(pud_mkold(pud_mkyoung(pud))));
266 if (mm_pmd_folded(mm))
270 * A huge page does not point to next level page table
271 * entry. Hence this must qualify as pud_bad().
273 WARN_ON(!pud_bad(pud_mkhuge(pud)));
276 static void __init pud_advanced_tests(struct mm_struct *mm,
277 struct vm_area_struct *vma, pud_t *pudp,
278 unsigned long pfn, unsigned long vaddr,
281 pud_t pud = pfn_pud(pfn, prot);
283 if (!has_transparent_hugepage())
286 pr_debug("Validating PUD advanced\n");
287 /* Align the address wrt HPAGE_PUD_SIZE */
288 vaddr = (vaddr & HPAGE_PUD_MASK) + HPAGE_PUD_SIZE;
290 set_pud_at(mm, vaddr, pudp, pud);
291 pudp_set_wrprotect(mm, vaddr, pudp);
292 pud = READ_ONCE(*pudp);
293 WARN_ON(pud_write(pud));
295 #ifndef __PAGETABLE_PMD_FOLDED
296 pudp_huge_get_and_clear(mm, vaddr, pudp);
297 pud = READ_ONCE(*pudp);
298 WARN_ON(!pud_none(pud));
299 #endif /* __PAGETABLE_PMD_FOLDED */
300 pud = pfn_pud(pfn, prot);
301 pud = pud_wrprotect(pud);
302 pud = pud_mkclean(pud);
303 set_pud_at(mm, vaddr, pudp, pud);
304 pud = pud_mkwrite(pud);
305 pud = pud_mkdirty(pud);
306 pudp_set_access_flags(vma, vaddr, pudp, pud, 1);
307 pud = READ_ONCE(*pudp);
308 WARN_ON(!(pud_write(pud) && pud_dirty(pud)));
310 #ifndef __PAGETABLE_PMD_FOLDED
311 pudp_huge_get_and_clear_full(mm, vaddr, pudp, 1);
312 pud = READ_ONCE(*pudp);
313 WARN_ON(!pud_none(pud));
314 #endif /* __PAGETABLE_PMD_FOLDED */
316 pud = pfn_pud(pfn, prot);
317 pud = pud_mkyoung(pud);
318 set_pud_at(mm, vaddr, pudp, pud);
319 pudp_test_and_clear_young(vma, vaddr, pudp);
320 pud = READ_ONCE(*pudp);
321 WARN_ON(pud_young(pud));
323 pudp_huge_get_and_clear(mm, vaddr, pudp);
326 static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot)
328 pud_t pud = pfn_pud(pfn, prot);
330 pr_debug("Validating PUD leaf\n");
332 * PUD based THP is a leaf entry.
334 pud = pud_mkhuge(pud);
335 WARN_ON(!pud_leaf(pud));
338 #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
339 static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot)
343 if (!arch_ioremap_pud_supported())
346 pr_debug("Validating PUD huge\n");
348 * X86 defined pud_set_huge() verifies that the given
349 * PUD is not a populated non-leaf entry.
351 WRITE_ONCE(*pudp, __pud(0));
352 WARN_ON(!pud_set_huge(pudp, __pfn_to_phys(pfn), prot));
353 WARN_ON(!pud_clear_huge(pudp));
354 pud = READ_ONCE(*pudp);
355 WARN_ON(!pud_none(pud));
357 #else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
358 static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot) { }
359 #endif /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
361 #else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
362 static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot) { }
363 static void __init pud_advanced_tests(struct mm_struct *mm,
364 struct vm_area_struct *vma, pud_t *pudp,
365 unsigned long pfn, unsigned long vaddr,
369 static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot) { }
370 static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot)
373 #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
374 #else /* !CONFIG_TRANSPARENT_HUGEPAGE */
375 static void __init pmd_basic_tests(unsigned long pfn, pgprot_t prot) { }
376 static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot) { }
377 static void __init pmd_advanced_tests(struct mm_struct *mm,
378 struct vm_area_struct *vma, pmd_t *pmdp,
379 unsigned long pfn, unsigned long vaddr,
380 pgprot_t prot, pgtable_t pgtable)
383 static void __init pud_advanced_tests(struct mm_struct *mm,
384 struct vm_area_struct *vma, pud_t *pudp,
385 unsigned long pfn, unsigned long vaddr,
389 static void __init pmd_leaf_tests(unsigned long pfn, pgprot_t prot) { }
390 static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot) { }
391 static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot)
394 static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot)
397 static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot) { }
398 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
400 static void __init p4d_basic_tests(unsigned long pfn, pgprot_t prot)
404 pr_debug("Validating P4D basic\n");
405 memset(&p4d, RANDOM_NZVALUE, sizeof(p4d_t));
406 WARN_ON(!p4d_same(p4d, p4d));
409 static void __init pgd_basic_tests(unsigned long pfn, pgprot_t prot)
413 pr_debug("Validating PGD basic\n");
414 memset(&pgd, RANDOM_NZVALUE, sizeof(pgd_t));
415 WARN_ON(!pgd_same(pgd, pgd));
418 #ifndef __PAGETABLE_PUD_FOLDED
419 static void __init pud_clear_tests(struct mm_struct *mm, pud_t *pudp)
421 pud_t pud = READ_ONCE(*pudp);
423 if (mm_pmd_folded(mm))
426 pr_debug("Validating PUD clear\n");
427 pud = __pud(pud_val(pud) | RANDOM_ORVALUE);
428 WRITE_ONCE(*pudp, pud);
430 pud = READ_ONCE(*pudp);
431 WARN_ON(!pud_none(pud));
434 static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp,
439 if (mm_pmd_folded(mm))
442 pr_debug("Validating PUD populate\n");
444 * This entry points to next level page table page.
445 * Hence this must not qualify as pud_bad().
447 pud_populate(mm, pudp, pmdp);
448 pud = READ_ONCE(*pudp);
449 WARN_ON(pud_bad(pud));
451 #else /* !__PAGETABLE_PUD_FOLDED */
452 static void __init pud_clear_tests(struct mm_struct *mm, pud_t *pudp) { }
453 static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp,
457 #endif /* PAGETABLE_PUD_FOLDED */
459 #ifndef __PAGETABLE_P4D_FOLDED
460 static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp)
462 p4d_t p4d = READ_ONCE(*p4dp);
464 if (mm_pud_folded(mm))
467 pr_debug("Validating P4D clear\n");
468 p4d = __p4d(p4d_val(p4d) | RANDOM_ORVALUE);
469 WRITE_ONCE(*p4dp, p4d);
471 p4d = READ_ONCE(*p4dp);
472 WARN_ON(!p4d_none(p4d));
475 static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp,
480 if (mm_pud_folded(mm))
483 pr_debug("Validating P4D populate\n");
485 * This entry points to next level page table page.
486 * Hence this must not qualify as p4d_bad().
490 p4d_populate(mm, p4dp, pudp);
491 p4d = READ_ONCE(*p4dp);
492 WARN_ON(p4d_bad(p4d));
495 static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp)
497 pgd_t pgd = READ_ONCE(*pgdp);
499 if (mm_p4d_folded(mm))
502 pr_debug("Validating PGD clear\n");
503 pgd = __pgd(pgd_val(pgd) | RANDOM_ORVALUE);
504 WRITE_ONCE(*pgdp, pgd);
506 pgd = READ_ONCE(*pgdp);
507 WARN_ON(!pgd_none(pgd));
510 static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
515 if (mm_p4d_folded(mm))
518 pr_debug("Validating PGD populate\n");
520 * This entry points to next level page table page.
521 * Hence this must not qualify as pgd_bad().
525 pgd_populate(mm, pgdp, p4dp);
526 pgd = READ_ONCE(*pgdp);
527 WARN_ON(pgd_bad(pgd));
529 #else /* !__PAGETABLE_P4D_FOLDED */
530 static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp) { }
531 static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp) { }
532 static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp,
536 static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
540 #endif /* PAGETABLE_P4D_FOLDED */
542 static void __init pte_clear_tests(struct mm_struct *mm, pte_t *ptep,
545 pte_t pte = ptep_get(ptep);
547 pr_debug("Validating PTE clear\n");
548 pte = __pte(pte_val(pte) | RANDOM_ORVALUE);
549 set_pte_at(mm, vaddr, ptep, pte);
551 pte_clear(mm, vaddr, ptep);
552 pte = ptep_get(ptep);
553 WARN_ON(!pte_none(pte));
556 static void __init pmd_clear_tests(struct mm_struct *mm, pmd_t *pmdp)
558 pmd_t pmd = READ_ONCE(*pmdp);
560 pr_debug("Validating PMD clear\n");
561 pmd = __pmd(pmd_val(pmd) | RANDOM_ORVALUE);
562 WRITE_ONCE(*pmdp, pmd);
564 pmd = READ_ONCE(*pmdp);
565 WARN_ON(!pmd_none(pmd));
568 static void __init pmd_populate_tests(struct mm_struct *mm, pmd_t *pmdp,
573 pr_debug("Validating PMD populate\n");
575 * This entry points to next level page table page.
576 * Hence this must not qualify as pmd_bad().
578 pmd_populate(mm, pmdp, pgtable);
579 pmd = READ_ONCE(*pmdp);
580 WARN_ON(pmd_bad(pmd));
583 static void __init pte_special_tests(unsigned long pfn, pgprot_t prot)
585 pte_t pte = pfn_pte(pfn, prot);
587 if (!IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL))
590 pr_debug("Validating PTE special\n");
591 WARN_ON(!pte_special(pte_mkspecial(pte)));
594 static void __init pte_protnone_tests(unsigned long pfn, pgprot_t prot)
596 pte_t pte = pfn_pte(pfn, prot);
598 if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
601 pr_debug("Validating PTE protnone\n");
602 WARN_ON(!pte_protnone(pte));
603 WARN_ON(!pte_present(pte));
606 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
607 static void __init pmd_protnone_tests(unsigned long pfn, pgprot_t prot)
609 pmd_t pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
611 if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
614 pr_debug("Validating PMD protnone\n");
615 WARN_ON(!pmd_protnone(pmd));
616 WARN_ON(!pmd_present(pmd));
618 #else /* !CONFIG_TRANSPARENT_HUGEPAGE */
619 static void __init pmd_protnone_tests(unsigned long pfn, pgprot_t prot) { }
620 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
622 #ifdef CONFIG_ARCH_HAS_PTE_DEVMAP
623 static void __init pte_devmap_tests(unsigned long pfn, pgprot_t prot)
625 pte_t pte = pfn_pte(pfn, prot);
627 pr_debug("Validating PTE devmap\n");
628 WARN_ON(!pte_devmap(pte_mkdevmap(pte)));
631 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
632 static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot)
634 pmd_t pmd = pfn_pmd(pfn, prot);
636 pr_debug("Validating PMD devmap\n");
637 WARN_ON(!pmd_devmap(pmd_mkdevmap(pmd)));
640 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
641 static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot)
643 pud_t pud = pfn_pud(pfn, prot);
645 pr_debug("Validating PUD devmap\n");
646 WARN_ON(!pud_devmap(pud_mkdevmap(pud)));
648 #else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
649 static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) { }
650 #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
651 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
652 static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot) { }
653 static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) { }
654 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
656 static void __init pte_devmap_tests(unsigned long pfn, pgprot_t prot) { }
657 static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot) { }
658 static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) { }
659 #endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */
661 static void __init pte_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
663 pte_t pte = pfn_pte(pfn, prot);
665 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
668 pr_debug("Validating PTE soft dirty\n");
669 WARN_ON(!pte_soft_dirty(pte_mksoft_dirty(pte)));
670 WARN_ON(pte_soft_dirty(pte_clear_soft_dirty(pte)));
673 static void __init pte_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
675 pte_t pte = pfn_pte(pfn, prot);
677 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
680 pr_debug("Validating PTE swap soft dirty\n");
681 WARN_ON(!pte_swp_soft_dirty(pte_swp_mksoft_dirty(pte)));
682 WARN_ON(pte_swp_soft_dirty(pte_swp_clear_soft_dirty(pte)));
685 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
686 static void __init pmd_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
688 pmd_t pmd = pfn_pmd(pfn, prot);
690 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
693 pr_debug("Validating PMD soft dirty\n");
694 WARN_ON(!pmd_soft_dirty(pmd_mksoft_dirty(pmd)));
695 WARN_ON(pmd_soft_dirty(pmd_clear_soft_dirty(pmd)));
698 static void __init pmd_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
700 pmd_t pmd = pfn_pmd(pfn, prot);
702 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY) ||
703 !IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION))
706 pr_debug("Validating PMD swap soft dirty\n");
707 WARN_ON(!pmd_swp_soft_dirty(pmd_swp_mksoft_dirty(pmd)));
708 WARN_ON(pmd_swp_soft_dirty(pmd_swp_clear_soft_dirty(pmd)));
710 #else /* !CONFIG_ARCH_HAS_PTE_DEVMAP */
711 static void __init pmd_soft_dirty_tests(unsigned long pfn, pgprot_t prot) { }
712 static void __init pmd_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
715 #endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */
717 static void __init pte_swap_tests(unsigned long pfn, pgprot_t prot)
722 pr_debug("Validating PTE swap\n");
723 pte = pfn_pte(pfn, prot);
724 swp = __pte_to_swp_entry(pte);
725 pte = __swp_entry_to_pte(swp);
726 WARN_ON(pfn != pte_pfn(pte));
729 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
730 static void __init pmd_swap_tests(unsigned long pfn, pgprot_t prot)
735 pr_debug("Validating PMD swap\n");
736 pmd = pfn_pmd(pfn, prot);
737 swp = __pmd_to_swp_entry(pmd);
738 pmd = __swp_entry_to_pmd(swp);
739 WARN_ON(pfn != pmd_pfn(pmd));
741 #else /* !CONFIG_ARCH_ENABLE_THP_MIGRATION */
742 static void __init pmd_swap_tests(unsigned long pfn, pgprot_t prot) { }
743 #endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
745 static void __init swap_migration_tests(void)
750 if (!IS_ENABLED(CONFIG_MIGRATION))
753 pr_debug("Validating swap migration\n");
755 * swap_migration_tests() requires a dedicated page as it needs to
756 * be locked before creating a migration entry from it. Locking the
757 * page that actually maps kernel text ('start_kernel') can be real
758 * problematic. Lets allocate a dedicated page explicitly for this
759 * purpose that will be freed subsequently.
761 page = alloc_page(GFP_KERNEL);
763 pr_err("page allocation failed\n");
768 * make_migration_entry() expects given page to be
769 * locked, otherwise it stumbles upon a BUG_ON().
771 __SetPageLocked(page);
772 swp = make_migration_entry(page, 1);
773 WARN_ON(!is_migration_entry(swp));
774 WARN_ON(!is_write_migration_entry(swp));
776 make_migration_entry_read(&swp);
777 WARN_ON(!is_migration_entry(swp));
778 WARN_ON(is_write_migration_entry(swp));
780 swp = make_migration_entry(page, 0);
781 WARN_ON(!is_migration_entry(swp));
782 WARN_ON(is_write_migration_entry(swp));
783 __ClearPageLocked(page);
787 #ifdef CONFIG_HUGETLB_PAGE
788 static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot)
793 pr_debug("Validating HugeTLB basic\n");
795 * Accessing the page associated with the pfn is safe here,
796 * as it was previously derived from a real kernel symbol.
798 page = pfn_to_page(pfn);
799 pte = mk_huge_pte(page, prot);
801 WARN_ON(!huge_pte_dirty(huge_pte_mkdirty(pte)));
802 WARN_ON(!huge_pte_write(huge_pte_mkwrite(huge_pte_wrprotect(pte))));
803 WARN_ON(huge_pte_write(huge_pte_wrprotect(huge_pte_mkwrite(pte))));
805 #ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB
806 pte = pfn_pte(pfn, prot);
808 WARN_ON(!pte_huge(pte_mkhuge(pte)));
809 #endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */
811 #else /* !CONFIG_HUGETLB_PAGE */
812 static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot) { }
813 #endif /* CONFIG_HUGETLB_PAGE */
815 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
816 static void __init pmd_thp_tests(unsigned long pfn, pgprot_t prot)
820 if (!has_transparent_hugepage())
823 pr_debug("Validating PMD based THP\n");
825 * pmd_trans_huge() and pmd_present() must return positive after
826 * MMU invalidation with pmd_mkinvalid(). This behavior is an
827 * optimization for transparent huge page. pmd_trans_huge() must
828 * be true if pmd_page() returns a valid THP to avoid taking the
829 * pmd_lock when others walk over non transhuge pmds (i.e. there
830 * are no THP allocated). Especially when splitting a THP and
831 * removing the present bit from the pmd, pmd_trans_huge() still
832 * needs to return true. pmd_present() should be true whenever
833 * pmd_trans_huge() returns true.
835 pmd = pfn_pmd(pfn, prot);
836 WARN_ON(!pmd_trans_huge(pmd_mkhuge(pmd)));
838 #ifndef __HAVE_ARCH_PMDP_INVALIDATE
839 WARN_ON(!pmd_trans_huge(pmd_mkinvalid(pmd_mkhuge(pmd))));
840 WARN_ON(!pmd_present(pmd_mkinvalid(pmd_mkhuge(pmd))));
841 #endif /* __HAVE_ARCH_PMDP_INVALIDATE */
844 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
845 static void __init pud_thp_tests(unsigned long pfn, pgprot_t prot)
849 if (!has_transparent_hugepage())
852 pr_debug("Validating PUD based THP\n");
853 pud = pfn_pud(pfn, prot);
854 WARN_ON(!pud_trans_huge(pud_mkhuge(pud)));
857 * pud_mkinvalid() has been dropped for now. Enable back
858 * these tests when it comes back with a modified pud_present().
860 * WARN_ON(!pud_trans_huge(pud_mkinvalid(pud_mkhuge(pud))));
861 * WARN_ON(!pud_present(pud_mkinvalid(pud_mkhuge(pud))));
864 #else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
865 static void __init pud_thp_tests(unsigned long pfn, pgprot_t prot) { }
866 #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
867 #else /* !CONFIG_TRANSPARENT_HUGEPAGE */
868 static void __init pmd_thp_tests(unsigned long pfn, pgprot_t prot) { }
869 static void __init pud_thp_tests(unsigned long pfn, pgprot_t prot) { }
870 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
872 static unsigned long __init get_random_vaddr(void)
874 unsigned long random_vaddr, random_pages, total_user_pages;
876 total_user_pages = (TASK_SIZE - FIRST_USER_ADDRESS) / PAGE_SIZE;
878 random_pages = get_random_long() % total_user_pages;
879 random_vaddr = FIRST_USER_ADDRESS + random_pages * PAGE_SIZE;
884 static int __init debug_vm_pgtable(void)
886 struct vm_area_struct *vma;
887 struct mm_struct *mm;
889 p4d_t *p4dp, *saved_p4dp;
890 pud_t *pudp, *saved_pudp;
891 pmd_t *pmdp, *saved_pmdp, pmd;
893 pgtable_t saved_ptep;
894 pgprot_t prot, protnone;
896 unsigned long vaddr, pte_aligned, pmd_aligned;
897 unsigned long pud_aligned, p4d_aligned, pgd_aligned;
898 spinlock_t *ptl = NULL;
900 pr_info("Validating architecture page table helpers\n");
901 prot = vm_get_page_prot(VMFLAGS);
902 vaddr = get_random_vaddr();
905 pr_err("mm_struct allocation failed\n");
910 * __P000 (or even __S000) will help create page table entries with
911 * PROT_NONE permission as required for pxx_protnone_tests().
915 vma = vm_area_alloc(mm);
917 pr_err("vma allocation failed\n");
922 * PFN for mapping at PTE level is determined from a standard kernel
923 * text symbol. But pfns for higher page table levels are derived by
924 * masking lower bits of this real pfn. These derived pfns might not
925 * exist on the platform but that does not really matter as pfn_pxx()
926 * helpers will still create appropriate entries for the test. This
927 * helps avoid large memory block allocations to be used for mapping
928 * at higher page table levels.
930 paddr = __pa_symbol(&start_kernel);
932 pte_aligned = (paddr & PAGE_MASK) >> PAGE_SHIFT;
933 pmd_aligned = (paddr & PMD_MASK) >> PAGE_SHIFT;
934 pud_aligned = (paddr & PUD_MASK) >> PAGE_SHIFT;
935 p4d_aligned = (paddr & P4D_MASK) >> PAGE_SHIFT;
936 pgd_aligned = (paddr & PGDIR_MASK) >> PAGE_SHIFT;
937 WARN_ON(!pfn_valid(pte_aligned));
939 pgdp = pgd_offset(mm, vaddr);
940 p4dp = p4d_alloc(mm, pgdp, vaddr);
941 pudp = pud_alloc(mm, p4dp, vaddr);
942 pmdp = pmd_alloc(mm, pudp, vaddr);
943 ptep = pte_alloc_map(mm, pmdp, vaddr);
946 * Save all the page table page addresses as the page table
947 * entries will be used for testing with random or garbage
948 * values. These saved addresses will be used for freeing
951 pmd = READ_ONCE(*pmdp);
952 saved_p4dp = p4d_offset(pgdp, 0UL);
953 saved_pudp = pud_offset(p4dp, 0UL);
954 saved_pmdp = pmd_offset(pudp, 0UL);
955 saved_ptep = pmd_pgtable(pmd);
957 pte_basic_tests(pte_aligned, prot);
958 pmd_basic_tests(pmd_aligned, prot);
959 pud_basic_tests(pud_aligned, prot);
960 p4d_basic_tests(p4d_aligned, prot);
961 pgd_basic_tests(pgd_aligned, prot);
963 pmd_leaf_tests(pmd_aligned, prot);
964 pud_leaf_tests(pud_aligned, prot);
966 pte_savedwrite_tests(pte_aligned, protnone);
967 pmd_savedwrite_tests(pmd_aligned, protnone);
969 pte_special_tests(pte_aligned, prot);
970 pte_protnone_tests(pte_aligned, protnone);
971 pmd_protnone_tests(pmd_aligned, protnone);
973 pte_devmap_tests(pte_aligned, prot);
974 pmd_devmap_tests(pmd_aligned, prot);
975 pud_devmap_tests(pud_aligned, prot);
977 pte_soft_dirty_tests(pte_aligned, prot);
978 pmd_soft_dirty_tests(pmd_aligned, prot);
979 pte_swap_soft_dirty_tests(pte_aligned, prot);
980 pmd_swap_soft_dirty_tests(pmd_aligned, prot);
982 pte_swap_tests(pte_aligned, prot);
983 pmd_swap_tests(pmd_aligned, prot);
985 swap_migration_tests();
987 pmd_thp_tests(pmd_aligned, prot);
988 pud_thp_tests(pud_aligned, prot);
990 hugetlb_basic_tests(pte_aligned, prot);
993 * Page table modifying tests. They need to hold
994 * proper page table lock.
997 ptl = pte_lockptr(mm, pmdp);
999 pte_clear_tests(mm, ptep, vaddr);
1000 pte_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot);
1001 pte_unmap_unlock(ptep, ptl);
1003 ptl = pmd_lock(mm, pmdp);
1004 pmd_clear_tests(mm, pmdp);
1005 pmd_advanced_tests(mm, vma, pmdp, pmd_aligned, vaddr, prot, saved_ptep);
1006 pmd_huge_tests(pmdp, pmd_aligned, prot);
1007 pmd_populate_tests(mm, pmdp, saved_ptep);
1010 ptl = pud_lock(mm, pudp);
1011 pud_clear_tests(mm, pudp);
1012 pud_advanced_tests(mm, vma, pudp, pud_aligned, vaddr, prot);
1013 pud_huge_tests(pudp, pud_aligned, prot);
1014 pud_populate_tests(mm, pudp, saved_pmdp);
1017 spin_lock(&mm->page_table_lock);
1018 p4d_clear_tests(mm, p4dp);
1019 pgd_clear_tests(mm, pgdp);
1020 p4d_populate_tests(mm, p4dp, saved_pudp);
1021 pgd_populate_tests(mm, pgdp, saved_p4dp);
1022 spin_unlock(&mm->page_table_lock);
1024 p4d_free(mm, saved_p4dp);
1025 pud_free(mm, saved_pudp);
1026 pmd_free(mm, saved_pmdp);
1027 pte_free(mm, saved_ptep);
1036 late_initcall(debug_vm_pgtable);