Linux kernel mirror (for testing)
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linux
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 <asm/pgalloc.h>
32#include <asm/tlbflush.h>
33
34/*
35 * Please refer Documentation/vm/arch_pgtable_helpers.rst for the semantics
36 * expectations that are being validated here. All future changes in here
37 * or the documentation need to be in sync.
38 */
39
40#define VMFLAGS (VM_READ|VM_WRITE|VM_EXEC)
41
42/*
43 * On s390 platform, the lower 4 bits are used to identify given page table
44 * entry type. But these bits might affect the ability to clear entries with
45 * pxx_clear() because of how dynamic page table folding works on s390. So
46 * while loading up the entries do not change the lower 4 bits. It does not
47 * have affect any other platform.
48 */
49#define S390_MASK_BITS 4
50#define RANDOM_ORVALUE GENMASK(BITS_PER_LONG - 1, S390_MASK_BITS)
51#define RANDOM_NZVALUE GENMASK(7, 0)
52
53static void __init pte_basic_tests(unsigned long pfn, pgprot_t prot)
54{
55 pte_t pte = pfn_pte(pfn, prot);
56
57 pr_debug("Validating PTE basic\n");
58 WARN_ON(!pte_same(pte, pte));
59 WARN_ON(!pte_young(pte_mkyoung(pte_mkold(pte))));
60 WARN_ON(!pte_dirty(pte_mkdirty(pte_mkclean(pte))));
61 WARN_ON(!pte_write(pte_mkwrite(pte_wrprotect(pte))));
62 WARN_ON(pte_young(pte_mkold(pte_mkyoung(pte))));
63 WARN_ON(pte_dirty(pte_mkclean(pte_mkdirty(pte))));
64 WARN_ON(pte_write(pte_wrprotect(pte_mkwrite(pte))));
65}
66
67static void __init pte_advanced_tests(struct mm_struct *mm,
68 struct vm_area_struct *vma, pte_t *ptep,
69 unsigned long pfn, unsigned long vaddr,
70 pgprot_t prot)
71{
72 pte_t pte = pfn_pte(pfn, prot);
73
74 pr_debug("Validating PTE advanced\n");
75 pte = pfn_pte(pfn, prot);
76 set_pte_at(mm, vaddr, ptep, pte);
77 ptep_set_wrprotect(mm, vaddr, ptep);
78 pte = ptep_get(ptep);
79 WARN_ON(pte_write(pte));
80
81 pte = pfn_pte(pfn, prot);
82 set_pte_at(mm, vaddr, ptep, pte);
83 ptep_get_and_clear(mm, vaddr, ptep);
84 pte = ptep_get(ptep);
85 WARN_ON(!pte_none(pte));
86
87 pte = pfn_pte(pfn, prot);
88 pte = pte_wrprotect(pte);
89 pte = pte_mkclean(pte);
90 set_pte_at(mm, vaddr, ptep, pte);
91 pte = pte_mkwrite(pte);
92 pte = pte_mkdirty(pte);
93 ptep_set_access_flags(vma, vaddr, ptep, pte, 1);
94 pte = ptep_get(ptep);
95 WARN_ON(!(pte_write(pte) && pte_dirty(pte)));
96
97 pte = pfn_pte(pfn, prot);
98 set_pte_at(mm, vaddr, ptep, pte);
99 ptep_get_and_clear_full(mm, vaddr, ptep, 1);
100 pte = ptep_get(ptep);
101 WARN_ON(!pte_none(pte));
102
103 pte = pte_mkyoung(pte);
104 set_pte_at(mm, vaddr, ptep, pte);
105 ptep_test_and_clear_young(vma, vaddr, ptep);
106 pte = ptep_get(ptep);
107 WARN_ON(pte_young(pte));
108}
109
110static void __init pte_savedwrite_tests(unsigned long pfn, pgprot_t prot)
111{
112 pte_t pte = pfn_pte(pfn, prot);
113
114 pr_debug("Validating PTE saved write\n");
115 WARN_ON(!pte_savedwrite(pte_mk_savedwrite(pte_clear_savedwrite(pte))));
116 WARN_ON(pte_savedwrite(pte_clear_savedwrite(pte_mk_savedwrite(pte))));
117}
118#ifdef CONFIG_TRANSPARENT_HUGEPAGE
119static void __init pmd_basic_tests(unsigned long pfn, pgprot_t prot)
120{
121 pmd_t pmd = pfn_pmd(pfn, prot);
122
123 if (!has_transparent_hugepage())
124 return;
125
126 pr_debug("Validating PMD basic\n");
127 WARN_ON(!pmd_same(pmd, pmd));
128 WARN_ON(!pmd_young(pmd_mkyoung(pmd_mkold(pmd))));
129 WARN_ON(!pmd_dirty(pmd_mkdirty(pmd_mkclean(pmd))));
130 WARN_ON(!pmd_write(pmd_mkwrite(pmd_wrprotect(pmd))));
131 WARN_ON(pmd_young(pmd_mkold(pmd_mkyoung(pmd))));
132 WARN_ON(pmd_dirty(pmd_mkclean(pmd_mkdirty(pmd))));
133 WARN_ON(pmd_write(pmd_wrprotect(pmd_mkwrite(pmd))));
134 /*
135 * A huge page does not point to next level page table
136 * entry. Hence this must qualify as pmd_bad().
137 */
138 WARN_ON(!pmd_bad(pmd_mkhuge(pmd)));
139}
140
141static void __init pmd_advanced_tests(struct mm_struct *mm,
142 struct vm_area_struct *vma, pmd_t *pmdp,
143 unsigned long pfn, unsigned long vaddr,
144 pgprot_t prot)
145{
146 pmd_t pmd = pfn_pmd(pfn, prot);
147
148 if (!has_transparent_hugepage())
149 return;
150
151 pr_debug("Validating PMD advanced\n");
152 /* Align the address wrt HPAGE_PMD_SIZE */
153 vaddr = (vaddr & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE;
154
155 pmd = pfn_pmd(pfn, prot);
156 set_pmd_at(mm, vaddr, pmdp, pmd);
157 pmdp_set_wrprotect(mm, vaddr, pmdp);
158 pmd = READ_ONCE(*pmdp);
159 WARN_ON(pmd_write(pmd));
160
161 pmd = pfn_pmd(pfn, prot);
162 set_pmd_at(mm, vaddr, pmdp, pmd);
163 pmdp_huge_get_and_clear(mm, vaddr, pmdp);
164 pmd = READ_ONCE(*pmdp);
165 WARN_ON(!pmd_none(pmd));
166
167 pmd = pfn_pmd(pfn, prot);
168 pmd = pmd_wrprotect(pmd);
169 pmd = pmd_mkclean(pmd);
170 set_pmd_at(mm, vaddr, pmdp, pmd);
171 pmd = pmd_mkwrite(pmd);
172 pmd = pmd_mkdirty(pmd);
173 pmdp_set_access_flags(vma, vaddr, pmdp, pmd, 1);
174 pmd = READ_ONCE(*pmdp);
175 WARN_ON(!(pmd_write(pmd) && pmd_dirty(pmd)));
176
177 pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
178 set_pmd_at(mm, vaddr, pmdp, pmd);
179 pmdp_huge_get_and_clear_full(vma, vaddr, pmdp, 1);
180 pmd = READ_ONCE(*pmdp);
181 WARN_ON(!pmd_none(pmd));
182
183 pmd = pmd_mkyoung(pmd);
184 set_pmd_at(mm, vaddr, pmdp, pmd);
185 pmdp_test_and_clear_young(vma, vaddr, pmdp);
186 pmd = READ_ONCE(*pmdp);
187 WARN_ON(pmd_young(pmd));
188}
189
190static void __init pmd_leaf_tests(unsigned long pfn, pgprot_t prot)
191{
192 pmd_t pmd = pfn_pmd(pfn, prot);
193
194 pr_debug("Validating PMD leaf\n");
195 /*
196 * PMD based THP is a leaf entry.
197 */
198 pmd = pmd_mkhuge(pmd);
199 WARN_ON(!pmd_leaf(pmd));
200}
201
202static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot)
203{
204 pmd_t pmd;
205
206 if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMAP))
207 return;
208
209 pr_debug("Validating PMD huge\n");
210 /*
211 * X86 defined pmd_set_huge() verifies that the given
212 * PMD is not a populated non-leaf entry.
213 */
214 WRITE_ONCE(*pmdp, __pmd(0));
215 WARN_ON(!pmd_set_huge(pmdp, __pfn_to_phys(pfn), prot));
216 WARN_ON(!pmd_clear_huge(pmdp));
217 pmd = READ_ONCE(*pmdp);
218 WARN_ON(!pmd_none(pmd));
219}
220
221static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot)
222{
223 pmd_t pmd = pfn_pmd(pfn, prot);
224
225 pr_debug("Validating PMD saved write\n");
226 WARN_ON(!pmd_savedwrite(pmd_mk_savedwrite(pmd_clear_savedwrite(pmd))));
227 WARN_ON(pmd_savedwrite(pmd_clear_savedwrite(pmd_mk_savedwrite(pmd))));
228}
229
230#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
231static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot)
232{
233 pud_t pud = pfn_pud(pfn, prot);
234
235 if (!has_transparent_hugepage())
236 return;
237
238 pr_debug("Validating PUD basic\n");
239 WARN_ON(!pud_same(pud, pud));
240 WARN_ON(!pud_young(pud_mkyoung(pud_mkold(pud))));
241 WARN_ON(!pud_write(pud_mkwrite(pud_wrprotect(pud))));
242 WARN_ON(pud_write(pud_wrprotect(pud_mkwrite(pud))));
243 WARN_ON(pud_young(pud_mkold(pud_mkyoung(pud))));
244
245 if (mm_pmd_folded(mm))
246 return;
247
248 /*
249 * A huge page does not point to next level page table
250 * entry. Hence this must qualify as pud_bad().
251 */
252 WARN_ON(!pud_bad(pud_mkhuge(pud)));
253}
254
255static void __init pud_advanced_tests(struct mm_struct *mm,
256 struct vm_area_struct *vma, pud_t *pudp,
257 unsigned long pfn, unsigned long vaddr,
258 pgprot_t prot)
259{
260 pud_t pud = pfn_pud(pfn, prot);
261
262 if (!has_transparent_hugepage())
263 return;
264
265 pr_debug("Validating PUD advanced\n");
266 /* Align the address wrt HPAGE_PUD_SIZE */
267 vaddr = (vaddr & HPAGE_PUD_MASK) + HPAGE_PUD_SIZE;
268
269 set_pud_at(mm, vaddr, pudp, pud);
270 pudp_set_wrprotect(mm, vaddr, pudp);
271 pud = READ_ONCE(*pudp);
272 WARN_ON(pud_write(pud));
273
274#ifndef __PAGETABLE_PMD_FOLDED
275 pud = pfn_pud(pfn, prot);
276 set_pud_at(mm, vaddr, pudp, pud);
277 pudp_huge_get_and_clear(mm, vaddr, pudp);
278 pud = READ_ONCE(*pudp);
279 WARN_ON(!pud_none(pud));
280
281 pud = pfn_pud(pfn, prot);
282 set_pud_at(mm, vaddr, pudp, pud);
283 pudp_huge_get_and_clear_full(mm, vaddr, pudp, 1);
284 pud = READ_ONCE(*pudp);
285 WARN_ON(!pud_none(pud));
286#endif /* __PAGETABLE_PMD_FOLDED */
287 pud = pfn_pud(pfn, prot);
288 pud = pud_wrprotect(pud);
289 pud = pud_mkclean(pud);
290 set_pud_at(mm, vaddr, pudp, pud);
291 pud = pud_mkwrite(pud);
292 pud = pud_mkdirty(pud);
293 pudp_set_access_flags(vma, vaddr, pudp, pud, 1);
294 pud = READ_ONCE(*pudp);
295 WARN_ON(!(pud_write(pud) && pud_dirty(pud)));
296
297 pud = pud_mkyoung(pud);
298 set_pud_at(mm, vaddr, pudp, pud);
299 pudp_test_and_clear_young(vma, vaddr, pudp);
300 pud = READ_ONCE(*pudp);
301 WARN_ON(pud_young(pud));
302}
303
304static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot)
305{
306 pud_t pud = pfn_pud(pfn, prot);
307
308 pr_debug("Validating PUD leaf\n");
309 /*
310 * PUD based THP is a leaf entry.
311 */
312 pud = pud_mkhuge(pud);
313 WARN_ON(!pud_leaf(pud));
314}
315
316static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot)
317{
318 pud_t pud;
319
320 if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMAP))
321 return;
322
323 pr_debug("Validating PUD huge\n");
324 /*
325 * X86 defined pud_set_huge() verifies that the given
326 * PUD is not a populated non-leaf entry.
327 */
328 WRITE_ONCE(*pudp, __pud(0));
329 WARN_ON(!pud_set_huge(pudp, __pfn_to_phys(pfn), prot));
330 WARN_ON(!pud_clear_huge(pudp));
331 pud = READ_ONCE(*pudp);
332 WARN_ON(!pud_none(pud));
333}
334#else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
335static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot) { }
336static void __init pud_advanced_tests(struct mm_struct *mm,
337 struct vm_area_struct *vma, pud_t *pudp,
338 unsigned long pfn, unsigned long vaddr,
339 pgprot_t prot)
340{
341}
342static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot) { }
343static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot)
344{
345}
346#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
347#else /* !CONFIG_TRANSPARENT_HUGEPAGE */
348static void __init pmd_basic_tests(unsigned long pfn, pgprot_t prot) { }
349static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot) { }
350static void __init pmd_advanced_tests(struct mm_struct *mm,
351 struct vm_area_struct *vma, pmd_t *pmdp,
352 unsigned long pfn, unsigned long vaddr,
353 pgprot_t prot)
354{
355}
356static void __init pud_advanced_tests(struct mm_struct *mm,
357 struct vm_area_struct *vma, pud_t *pudp,
358 unsigned long pfn, unsigned long vaddr,
359 pgprot_t prot)
360{
361}
362static void __init pmd_leaf_tests(unsigned long pfn, pgprot_t prot) { }
363static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot) { }
364static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot)
365{
366}
367static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot)
368{
369}
370static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot) { }
371#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
372
373static void __init p4d_basic_tests(unsigned long pfn, pgprot_t prot)
374{
375 p4d_t p4d;
376
377 pr_debug("Validating P4D basic\n");
378 memset(&p4d, RANDOM_NZVALUE, sizeof(p4d_t));
379 WARN_ON(!p4d_same(p4d, p4d));
380}
381
382static void __init pgd_basic_tests(unsigned long pfn, pgprot_t prot)
383{
384 pgd_t pgd;
385
386 pr_debug("Validating PGD basic\n");
387 memset(&pgd, RANDOM_NZVALUE, sizeof(pgd_t));
388 WARN_ON(!pgd_same(pgd, pgd));
389}
390
391#ifndef __PAGETABLE_PUD_FOLDED
392static void __init pud_clear_tests(struct mm_struct *mm, pud_t *pudp)
393{
394 pud_t pud = READ_ONCE(*pudp);
395
396 if (mm_pmd_folded(mm))
397 return;
398
399 pr_debug("Validating PUD clear\n");
400 pud = __pud(pud_val(pud) | RANDOM_ORVALUE);
401 WRITE_ONCE(*pudp, pud);
402 pud_clear(pudp);
403 pud = READ_ONCE(*pudp);
404 WARN_ON(!pud_none(pud));
405}
406
407static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp,
408 pmd_t *pmdp)
409{
410 pud_t pud;
411
412 if (mm_pmd_folded(mm))
413 return;
414
415 pr_debug("Validating PUD populate\n");
416 /*
417 * This entry points to next level page table page.
418 * Hence this must not qualify as pud_bad().
419 */
420 pmd_clear(pmdp);
421 pud_clear(pudp);
422 pud_populate(mm, pudp, pmdp);
423 pud = READ_ONCE(*pudp);
424 WARN_ON(pud_bad(pud));
425}
426#else /* !__PAGETABLE_PUD_FOLDED */
427static void __init pud_clear_tests(struct mm_struct *mm, pud_t *pudp) { }
428static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp,
429 pmd_t *pmdp)
430{
431}
432#endif /* PAGETABLE_PUD_FOLDED */
433
434#ifndef __PAGETABLE_P4D_FOLDED
435static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp)
436{
437 p4d_t p4d = READ_ONCE(*p4dp);
438
439 if (mm_pud_folded(mm))
440 return;
441
442 pr_debug("Validating P4D clear\n");
443 p4d = __p4d(p4d_val(p4d) | RANDOM_ORVALUE);
444 WRITE_ONCE(*p4dp, p4d);
445 p4d_clear(p4dp);
446 p4d = READ_ONCE(*p4dp);
447 WARN_ON(!p4d_none(p4d));
448}
449
450static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp,
451 pud_t *pudp)
452{
453 p4d_t p4d;
454
455 if (mm_pud_folded(mm))
456 return;
457
458 pr_debug("Validating P4D populate\n");
459 /*
460 * This entry points to next level page table page.
461 * Hence this must not qualify as p4d_bad().
462 */
463 pud_clear(pudp);
464 p4d_clear(p4dp);
465 p4d_populate(mm, p4dp, pudp);
466 p4d = READ_ONCE(*p4dp);
467 WARN_ON(p4d_bad(p4d));
468}
469
470static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp)
471{
472 pgd_t pgd = READ_ONCE(*pgdp);
473
474 if (mm_p4d_folded(mm))
475 return;
476
477 pr_debug("Validating PGD clear\n");
478 pgd = __pgd(pgd_val(pgd) | RANDOM_ORVALUE);
479 WRITE_ONCE(*pgdp, pgd);
480 pgd_clear(pgdp);
481 pgd = READ_ONCE(*pgdp);
482 WARN_ON(!pgd_none(pgd));
483}
484
485static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
486 p4d_t *p4dp)
487{
488 pgd_t pgd;
489
490 if (mm_p4d_folded(mm))
491 return;
492
493 pr_debug("Validating PGD populate\n");
494 /*
495 * This entry points to next level page table page.
496 * Hence this must not qualify as pgd_bad().
497 */
498 p4d_clear(p4dp);
499 pgd_clear(pgdp);
500 pgd_populate(mm, pgdp, p4dp);
501 pgd = READ_ONCE(*pgdp);
502 WARN_ON(pgd_bad(pgd));
503}
504#else /* !__PAGETABLE_P4D_FOLDED */
505static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp) { }
506static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp) { }
507static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp,
508 pud_t *pudp)
509{
510}
511static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
512 p4d_t *p4dp)
513{
514}
515#endif /* PAGETABLE_P4D_FOLDED */
516
517static void __init pte_clear_tests(struct mm_struct *mm, pte_t *ptep,
518 unsigned long vaddr)
519{
520 pte_t pte = ptep_get(ptep);
521
522 pr_debug("Validating PTE clear\n");
523 pte = __pte(pte_val(pte) | RANDOM_ORVALUE);
524 set_pte_at(mm, vaddr, ptep, pte);
525 barrier();
526 pte_clear(mm, vaddr, ptep);
527 pte = ptep_get(ptep);
528 WARN_ON(!pte_none(pte));
529}
530
531static void __init pmd_clear_tests(struct mm_struct *mm, pmd_t *pmdp)
532{
533 pmd_t pmd = READ_ONCE(*pmdp);
534
535 pr_debug("Validating PMD clear\n");
536 pmd = __pmd(pmd_val(pmd) | RANDOM_ORVALUE);
537 WRITE_ONCE(*pmdp, pmd);
538 pmd_clear(pmdp);
539 pmd = READ_ONCE(*pmdp);
540 WARN_ON(!pmd_none(pmd));
541}
542
543static void __init pmd_populate_tests(struct mm_struct *mm, pmd_t *pmdp,
544 pgtable_t pgtable)
545{
546 pmd_t pmd;
547
548 pr_debug("Validating PMD populate\n");
549 /*
550 * This entry points to next level page table page.
551 * Hence this must not qualify as pmd_bad().
552 */
553 pmd_clear(pmdp);
554 pmd_populate(mm, pmdp, pgtable);
555 pmd = READ_ONCE(*pmdp);
556 WARN_ON(pmd_bad(pmd));
557}
558
559static void __init pte_special_tests(unsigned long pfn, pgprot_t prot)
560{
561 pte_t pte = pfn_pte(pfn, prot);
562
563 if (!IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL))
564 return;
565
566 pr_debug("Validating PTE special\n");
567 WARN_ON(!pte_special(pte_mkspecial(pte)));
568}
569
570static void __init pte_protnone_tests(unsigned long pfn, pgprot_t prot)
571{
572 pte_t pte = pfn_pte(pfn, prot);
573
574 if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
575 return;
576
577 pr_debug("Validating PTE protnone\n");
578 WARN_ON(!pte_protnone(pte));
579 WARN_ON(!pte_present(pte));
580}
581
582#ifdef CONFIG_TRANSPARENT_HUGEPAGE
583static void __init pmd_protnone_tests(unsigned long pfn, pgprot_t prot)
584{
585 pmd_t pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
586
587 if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
588 return;
589
590 pr_debug("Validating PMD protnone\n");
591 WARN_ON(!pmd_protnone(pmd));
592 WARN_ON(!pmd_present(pmd));
593}
594#else /* !CONFIG_TRANSPARENT_HUGEPAGE */
595static void __init pmd_protnone_tests(unsigned long pfn, pgprot_t prot) { }
596#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
597
598#ifdef CONFIG_ARCH_HAS_PTE_DEVMAP
599static void __init pte_devmap_tests(unsigned long pfn, pgprot_t prot)
600{
601 pte_t pte = pfn_pte(pfn, prot);
602
603 pr_debug("Validating PTE devmap\n");
604 WARN_ON(!pte_devmap(pte_mkdevmap(pte)));
605}
606
607#ifdef CONFIG_TRANSPARENT_HUGEPAGE
608static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot)
609{
610 pmd_t pmd = pfn_pmd(pfn, prot);
611
612 pr_debug("Validating PMD devmap\n");
613 WARN_ON(!pmd_devmap(pmd_mkdevmap(pmd)));
614}
615
616#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
617static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot)
618{
619 pud_t pud = pfn_pud(pfn, prot);
620
621 pr_debug("Validating PUD devmap\n");
622 WARN_ON(!pud_devmap(pud_mkdevmap(pud)));
623}
624#else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
625static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) { }
626#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
627#else /* CONFIG_TRANSPARENT_HUGEPAGE */
628static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot) { }
629static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) { }
630#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
631#else
632static void __init pte_devmap_tests(unsigned long pfn, pgprot_t prot) { }
633static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot) { }
634static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) { }
635#endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */
636
637static void __init pte_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
638{
639 pte_t pte = pfn_pte(pfn, prot);
640
641 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
642 return;
643
644 pr_debug("Validating PTE soft dirty\n");
645 WARN_ON(!pte_soft_dirty(pte_mksoft_dirty(pte)));
646 WARN_ON(pte_soft_dirty(pte_clear_soft_dirty(pte)));
647}
648
649static void __init pte_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
650{
651 pte_t pte = pfn_pte(pfn, prot);
652
653 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
654 return;
655
656 pr_debug("Validating PTE swap soft dirty\n");
657 WARN_ON(!pte_swp_soft_dirty(pte_swp_mksoft_dirty(pte)));
658 WARN_ON(pte_swp_soft_dirty(pte_swp_clear_soft_dirty(pte)));
659}
660
661#ifdef CONFIG_TRANSPARENT_HUGEPAGE
662static void __init pmd_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
663{
664 pmd_t pmd = pfn_pmd(pfn, prot);
665
666 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
667 return;
668
669 pr_debug("Validating PMD soft dirty\n");
670 WARN_ON(!pmd_soft_dirty(pmd_mksoft_dirty(pmd)));
671 WARN_ON(pmd_soft_dirty(pmd_clear_soft_dirty(pmd)));
672}
673
674static void __init pmd_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
675{
676 pmd_t pmd = pfn_pmd(pfn, prot);
677
678 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY) ||
679 !IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION))
680 return;
681
682 pr_debug("Validating PMD swap soft dirty\n");
683 WARN_ON(!pmd_swp_soft_dirty(pmd_swp_mksoft_dirty(pmd)));
684 WARN_ON(pmd_swp_soft_dirty(pmd_swp_clear_soft_dirty(pmd)));
685}
686#else /* !CONFIG_ARCH_HAS_PTE_DEVMAP */
687static void __init pmd_soft_dirty_tests(unsigned long pfn, pgprot_t prot) { }
688static void __init pmd_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
689{
690}
691#endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */
692
693static void __init pte_swap_tests(unsigned long pfn, pgprot_t prot)
694{
695 swp_entry_t swp;
696 pte_t pte;
697
698 pr_debug("Validating PTE swap\n");
699 pte = pfn_pte(pfn, prot);
700 swp = __pte_to_swp_entry(pte);
701 pte = __swp_entry_to_pte(swp);
702 WARN_ON(pfn != pte_pfn(pte));
703}
704
705#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
706static void __init pmd_swap_tests(unsigned long pfn, pgprot_t prot)
707{
708 swp_entry_t swp;
709 pmd_t pmd;
710
711 pr_debug("Validating PMD swap\n");
712 pmd = pfn_pmd(pfn, prot);
713 swp = __pmd_to_swp_entry(pmd);
714 pmd = __swp_entry_to_pmd(swp);
715 WARN_ON(pfn != pmd_pfn(pmd));
716}
717#else /* !CONFIG_ARCH_ENABLE_THP_MIGRATION */
718static void __init pmd_swap_tests(unsigned long pfn, pgprot_t prot) { }
719#endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
720
721static void __init swap_migration_tests(void)
722{
723 struct page *page;
724 swp_entry_t swp;
725
726 if (!IS_ENABLED(CONFIG_MIGRATION))
727 return;
728
729 pr_debug("Validating swap migration\n");
730 /*
731 * swap_migration_tests() requires a dedicated page as it needs to
732 * be locked before creating a migration entry from it. Locking the
733 * page that actually maps kernel text ('start_kernel') can be real
734 * problematic. Lets allocate a dedicated page explicitly for this
735 * purpose that will be freed subsequently.
736 */
737 page = alloc_page(GFP_KERNEL);
738 if (!page) {
739 pr_err("page allocation failed\n");
740 return;
741 }
742
743 /*
744 * make_migration_entry() expects given page to be
745 * locked, otherwise it stumbles upon a BUG_ON().
746 */
747 __SetPageLocked(page);
748 swp = make_migration_entry(page, 1);
749 WARN_ON(!is_migration_entry(swp));
750 WARN_ON(!is_write_migration_entry(swp));
751
752 make_migration_entry_read(&swp);
753 WARN_ON(!is_migration_entry(swp));
754 WARN_ON(is_write_migration_entry(swp));
755
756 swp = make_migration_entry(page, 0);
757 WARN_ON(!is_migration_entry(swp));
758 WARN_ON(is_write_migration_entry(swp));
759 __ClearPageLocked(page);
760 __free_page(page);
761}
762
763#ifdef CONFIG_HUGETLB_PAGE
764static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot)
765{
766 struct page *page;
767 pte_t pte;
768
769 pr_debug("Validating HugeTLB basic\n");
770 /*
771 * Accessing the page associated with the pfn is safe here,
772 * as it was previously derived from a real kernel symbol.
773 */
774 page = pfn_to_page(pfn);
775 pte = mk_huge_pte(page, prot);
776
777 WARN_ON(!huge_pte_dirty(huge_pte_mkdirty(pte)));
778 WARN_ON(!huge_pte_write(huge_pte_mkwrite(huge_pte_wrprotect(pte))));
779 WARN_ON(huge_pte_write(huge_pte_wrprotect(huge_pte_mkwrite(pte))));
780
781#ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB
782 pte = pfn_pte(pfn, prot);
783
784 WARN_ON(!pte_huge(pte_mkhuge(pte)));
785#endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */
786}
787
788static void __init hugetlb_advanced_tests(struct mm_struct *mm,
789 struct vm_area_struct *vma,
790 pte_t *ptep, unsigned long pfn,
791 unsigned long vaddr, pgprot_t prot)
792{
793 struct page *page = pfn_to_page(pfn);
794 pte_t pte = ptep_get(ptep);
795 unsigned long paddr = __pfn_to_phys(pfn) & PMD_MASK;
796
797 pr_debug("Validating HugeTLB advanced\n");
798 pte = pte_mkhuge(mk_pte(pfn_to_page(PHYS_PFN(paddr)), prot));
799 set_huge_pte_at(mm, vaddr, ptep, pte);
800 barrier();
801 WARN_ON(!pte_same(pte, huge_ptep_get(ptep)));
802 huge_pte_clear(mm, vaddr, ptep, PMD_SIZE);
803 pte = huge_ptep_get(ptep);
804 WARN_ON(!huge_pte_none(pte));
805
806 pte = mk_huge_pte(page, prot);
807 set_huge_pte_at(mm, vaddr, ptep, pte);
808 barrier();
809 huge_ptep_set_wrprotect(mm, vaddr, ptep);
810 pte = huge_ptep_get(ptep);
811 WARN_ON(huge_pte_write(pte));
812
813 pte = mk_huge_pte(page, prot);
814 set_huge_pte_at(mm, vaddr, ptep, pte);
815 barrier();
816 huge_ptep_get_and_clear(mm, vaddr, ptep);
817 pte = huge_ptep_get(ptep);
818 WARN_ON(!huge_pte_none(pte));
819
820 pte = mk_huge_pte(page, prot);
821 pte = huge_pte_wrprotect(pte);
822 set_huge_pte_at(mm, vaddr, ptep, pte);
823 barrier();
824 pte = huge_pte_mkwrite(pte);
825 pte = huge_pte_mkdirty(pte);
826 huge_ptep_set_access_flags(vma, vaddr, ptep, pte, 1);
827 pte = huge_ptep_get(ptep);
828 WARN_ON(!(huge_pte_write(pte) && huge_pte_dirty(pte)));
829}
830#else /* !CONFIG_HUGETLB_PAGE */
831static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot) { }
832static void __init hugetlb_advanced_tests(struct mm_struct *mm,
833 struct vm_area_struct *vma,
834 pte_t *ptep, unsigned long pfn,
835 unsigned long vaddr, pgprot_t prot)
836{
837}
838#endif /* CONFIG_HUGETLB_PAGE */
839
840#ifdef CONFIG_TRANSPARENT_HUGEPAGE
841static void __init pmd_thp_tests(unsigned long pfn, pgprot_t prot)
842{
843 pmd_t pmd;
844
845 if (!has_transparent_hugepage())
846 return;
847
848 pr_debug("Validating PMD based THP\n");
849 /*
850 * pmd_trans_huge() and pmd_present() must return positive after
851 * MMU invalidation with pmd_mkinvalid(). This behavior is an
852 * optimization for transparent huge page. pmd_trans_huge() must
853 * be true if pmd_page() returns a valid THP to avoid taking the
854 * pmd_lock when others walk over non transhuge pmds (i.e. there
855 * are no THP allocated). Especially when splitting a THP and
856 * removing the present bit from the pmd, pmd_trans_huge() still
857 * needs to return true. pmd_present() should be true whenever
858 * pmd_trans_huge() returns true.
859 */
860 pmd = pfn_pmd(pfn, prot);
861 WARN_ON(!pmd_trans_huge(pmd_mkhuge(pmd)));
862
863#ifndef __HAVE_ARCH_PMDP_INVALIDATE
864 WARN_ON(!pmd_trans_huge(pmd_mkinvalid(pmd_mkhuge(pmd))));
865 WARN_ON(!pmd_present(pmd_mkinvalid(pmd_mkhuge(pmd))));
866#endif /* __HAVE_ARCH_PMDP_INVALIDATE */
867}
868
869#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
870static void __init pud_thp_tests(unsigned long pfn, pgprot_t prot)
871{
872 pud_t pud;
873
874 if (!has_transparent_hugepage())
875 return;
876
877 pr_debug("Validating PUD based THP\n");
878 pud = pfn_pud(pfn, prot);
879 WARN_ON(!pud_trans_huge(pud_mkhuge(pud)));
880
881 /*
882 * pud_mkinvalid() has been dropped for now. Enable back
883 * these tests when it comes back with a modified pud_present().
884 *
885 * WARN_ON(!pud_trans_huge(pud_mkinvalid(pud_mkhuge(pud))));
886 * WARN_ON(!pud_present(pud_mkinvalid(pud_mkhuge(pud))));
887 */
888}
889#else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
890static void __init pud_thp_tests(unsigned long pfn, pgprot_t prot) { }
891#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
892#else /* !CONFIG_TRANSPARENT_HUGEPAGE */
893static void __init pmd_thp_tests(unsigned long pfn, pgprot_t prot) { }
894static void __init pud_thp_tests(unsigned long pfn, pgprot_t prot) { }
895#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
896
897static unsigned long __init get_random_vaddr(void)
898{
899 unsigned long random_vaddr, random_pages, total_user_pages;
900
901 total_user_pages = (TASK_SIZE - FIRST_USER_ADDRESS) / PAGE_SIZE;
902
903 random_pages = get_random_long() % total_user_pages;
904 random_vaddr = FIRST_USER_ADDRESS + random_pages * PAGE_SIZE;
905
906 return random_vaddr;
907}
908
909static int __init debug_vm_pgtable(void)
910{
911 struct vm_area_struct *vma;
912 struct mm_struct *mm;
913 pgd_t *pgdp;
914 p4d_t *p4dp, *saved_p4dp;
915 pud_t *pudp, *saved_pudp;
916 pmd_t *pmdp, *saved_pmdp, pmd;
917 pte_t *ptep;
918 pgtable_t saved_ptep;
919 pgprot_t prot, protnone;
920 phys_addr_t paddr;
921 unsigned long vaddr, pte_aligned, pmd_aligned;
922 unsigned long pud_aligned, p4d_aligned, pgd_aligned;
923 spinlock_t *ptl = NULL;
924
925 pr_info("Validating architecture page table helpers\n");
926 prot = vm_get_page_prot(VMFLAGS);
927 vaddr = get_random_vaddr();
928 mm = mm_alloc();
929 if (!mm) {
930 pr_err("mm_struct allocation failed\n");
931 return 1;
932 }
933
934 /*
935 * __P000 (or even __S000) will help create page table entries with
936 * PROT_NONE permission as required for pxx_protnone_tests().
937 */
938 protnone = __P000;
939
940 vma = vm_area_alloc(mm);
941 if (!vma) {
942 pr_err("vma allocation failed\n");
943 return 1;
944 }
945
946 /*
947 * PFN for mapping at PTE level is determined from a standard kernel
948 * text symbol. But pfns for higher page table levels are derived by
949 * masking lower bits of this real pfn. These derived pfns might not
950 * exist on the platform but that does not really matter as pfn_pxx()
951 * helpers will still create appropriate entries for the test. This
952 * helps avoid large memory block allocations to be used for mapping
953 * at higher page table levels.
954 */
955 paddr = __pa_symbol(&start_kernel);
956
957 pte_aligned = (paddr & PAGE_MASK) >> PAGE_SHIFT;
958 pmd_aligned = (paddr & PMD_MASK) >> PAGE_SHIFT;
959 pud_aligned = (paddr & PUD_MASK) >> PAGE_SHIFT;
960 p4d_aligned = (paddr & P4D_MASK) >> PAGE_SHIFT;
961 pgd_aligned = (paddr & PGDIR_MASK) >> PAGE_SHIFT;
962 WARN_ON(!pfn_valid(pte_aligned));
963
964 pgdp = pgd_offset(mm, vaddr);
965 p4dp = p4d_alloc(mm, pgdp, vaddr);
966 pudp = pud_alloc(mm, p4dp, vaddr);
967 pmdp = pmd_alloc(mm, pudp, vaddr);
968 ptep = pte_alloc_map_lock(mm, pmdp, vaddr, &ptl);
969
970 /*
971 * Save all the page table page addresses as the page table
972 * entries will be used for testing with random or garbage
973 * values. These saved addresses will be used for freeing
974 * page table pages.
975 */
976 pmd = READ_ONCE(*pmdp);
977 saved_p4dp = p4d_offset(pgdp, 0UL);
978 saved_pudp = pud_offset(p4dp, 0UL);
979 saved_pmdp = pmd_offset(pudp, 0UL);
980 saved_ptep = pmd_pgtable(pmd);
981
982 pte_basic_tests(pte_aligned, prot);
983 pmd_basic_tests(pmd_aligned, prot);
984 pud_basic_tests(pud_aligned, prot);
985 p4d_basic_tests(p4d_aligned, prot);
986 pgd_basic_tests(pgd_aligned, prot);
987
988 pte_clear_tests(mm, ptep, vaddr);
989 pmd_clear_tests(mm, pmdp);
990 pud_clear_tests(mm, pudp);
991 p4d_clear_tests(mm, p4dp);
992 pgd_clear_tests(mm, pgdp);
993
994 pte_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot);
995 pmd_advanced_tests(mm, vma, pmdp, pmd_aligned, vaddr, prot);
996 pud_advanced_tests(mm, vma, pudp, pud_aligned, vaddr, prot);
997 hugetlb_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot);
998
999 pmd_leaf_tests(pmd_aligned, prot);
1000 pud_leaf_tests(pud_aligned, prot);
1001
1002 pmd_huge_tests(pmdp, pmd_aligned, prot);
1003 pud_huge_tests(pudp, pud_aligned, prot);
1004
1005 pte_savedwrite_tests(pte_aligned, prot);
1006 pmd_savedwrite_tests(pmd_aligned, prot);
1007
1008 pte_unmap_unlock(ptep, ptl);
1009
1010 pmd_populate_tests(mm, pmdp, saved_ptep);
1011 pud_populate_tests(mm, pudp, saved_pmdp);
1012 p4d_populate_tests(mm, p4dp, saved_pudp);
1013 pgd_populate_tests(mm, pgdp, saved_p4dp);
1014
1015 pte_special_tests(pte_aligned, prot);
1016 pte_protnone_tests(pte_aligned, protnone);
1017 pmd_protnone_tests(pmd_aligned, protnone);
1018
1019 pte_devmap_tests(pte_aligned, prot);
1020 pmd_devmap_tests(pmd_aligned, prot);
1021 pud_devmap_tests(pud_aligned, prot);
1022
1023 pte_soft_dirty_tests(pte_aligned, prot);
1024 pmd_soft_dirty_tests(pmd_aligned, prot);
1025 pte_swap_soft_dirty_tests(pte_aligned, prot);
1026 pmd_swap_soft_dirty_tests(pmd_aligned, prot);
1027
1028 pte_swap_tests(pte_aligned, prot);
1029 pmd_swap_tests(pmd_aligned, prot);
1030
1031 swap_migration_tests();
1032 hugetlb_basic_tests(pte_aligned, prot);
1033
1034 pmd_thp_tests(pmd_aligned, prot);
1035 pud_thp_tests(pud_aligned, prot);
1036
1037 p4d_free(mm, saved_p4dp);
1038 pud_free(mm, saved_pudp);
1039 pmd_free(mm, saved_pmdp);
1040 pte_free(mm, saved_ptep);
1041
1042 vm_area_free(vma);
1043 mm_dec_nr_puds(mm);
1044 mm_dec_nr_pmds(mm);
1045 mm_dec_nr_ptes(mm);
1046 mmdrop(mm);
1047 return 0;
1048}
1049late_initcall(debug_vm_pgtable);