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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * This kernel test validates architecture page table helpers and
4 * accessors and helps in verifying their continued compliance with
5 * expected generic MM semantics.
6 *
7 * Copyright (C) 2019 ARM Ltd.
8 *
9 * Author: Anshuman Khandual <anshuman.khandual@arm.com>
10 */
11#define pr_fmt(fmt) "debug_vm_pgtable: [%-25s]: " fmt, __func__
12
13#include <linux/gfp.h>
14#include <linux/highmem.h>
15#include <linux/hugetlb.h>
16#include <linux/kernel.h>
17#include <linux/kconfig.h>
18#include <linux/mm.h>
19#include <linux/mman.h>
20#include <linux/mm_types.h>
21#include <linux/module.h>
22#include <linux/pfn_t.h>
23#include <linux/printk.h>
24#include <linux/pgtable.h>
25#include <linux/random.h>
26#include <linux/spinlock.h>
27#include <linux/swap.h>
28#include <linux/swapops.h>
29#include <linux/start_kernel.h>
30#include <linux/sched/mm.h>
31#include <linux/io.h>
32#include <asm/pgalloc.h>
33#include <asm/tlbflush.h>
34
35/*
36 * Please refer Documentation/vm/arch_pgtable_helpers.rst for the semantics
37 * expectations that are being validated here. All future changes in here
38 * or the documentation need to be in sync.
39 */
40
41#define VMFLAGS (VM_READ|VM_WRITE|VM_EXEC)
42
43/*
44 * On s390 platform, the lower 4 bits are used to identify given page table
45 * entry type. But these bits might affect the ability to clear entries with
46 * pxx_clear() because of how dynamic page table folding works on s390. So
47 * while loading up the entries do not change the lower 4 bits. It does not
48 * have affect any other platform. Also avoid the 62nd bit on ppc64 that is
49 * used to mark a pte entry.
50 */
51#define S390_SKIP_MASK GENMASK(3, 0)
52#if __BITS_PER_LONG == 64
53#define PPC64_SKIP_MASK GENMASK(62, 62)
54#else
55#define PPC64_SKIP_MASK 0x0
56#endif
57#define ARCH_SKIP_MASK (S390_SKIP_MASK | PPC64_SKIP_MASK)
58#define RANDOM_ORVALUE (GENMASK(BITS_PER_LONG - 1, 0) & ~ARCH_SKIP_MASK)
59#define RANDOM_NZVALUE GENMASK(7, 0)
60
61static void __init pte_basic_tests(unsigned long pfn, int idx)
62{
63 pgprot_t prot = protection_map[idx];
64 pte_t pte = pfn_pte(pfn, prot);
65 unsigned long val = idx, *ptr = &val;
66
67 pr_debug("Validating PTE basic (%pGv)\n", ptr);
68
69 /*
70 * This test needs to be executed after the given page table entry
71 * is created with pfn_pte() to make sure that protection_map[idx]
72 * does not have the dirty bit enabled from the beginning. This is
73 * important for platforms like arm64 where (!PTE_RDONLY) indicate
74 * dirty bit being set.
75 */
76 WARN_ON(pte_dirty(pte_wrprotect(pte)));
77
78 WARN_ON(!pte_same(pte, pte));
79 WARN_ON(!pte_young(pte_mkyoung(pte_mkold(pte))));
80 WARN_ON(!pte_dirty(pte_mkdirty(pte_mkclean(pte))));
81 WARN_ON(!pte_write(pte_mkwrite(pte_wrprotect(pte))));
82 WARN_ON(pte_young(pte_mkold(pte_mkyoung(pte))));
83 WARN_ON(pte_dirty(pte_mkclean(pte_mkdirty(pte))));
84 WARN_ON(pte_write(pte_wrprotect(pte_mkwrite(pte))));
85 WARN_ON(pte_dirty(pte_wrprotect(pte_mkclean(pte))));
86 WARN_ON(!pte_dirty(pte_wrprotect(pte_mkdirty(pte))));
87}
88
89static void __init pte_advanced_tests(struct mm_struct *mm,
90 struct vm_area_struct *vma, pte_t *ptep,
91 unsigned long pfn, unsigned long vaddr,
92 pgprot_t prot)
93{
94 pte_t pte;
95
96 /*
97 * Architectures optimize set_pte_at by avoiding TLB flush.
98 * This requires set_pte_at to be not used to update an
99 * existing pte entry. Clear pte before we do set_pte_at
100 */
101
102 pr_debug("Validating PTE advanced\n");
103 pte = pfn_pte(pfn, prot);
104 set_pte_at(mm, vaddr, ptep, pte);
105 ptep_set_wrprotect(mm, vaddr, ptep);
106 pte = ptep_get(ptep);
107 WARN_ON(pte_write(pte));
108 ptep_get_and_clear(mm, vaddr, ptep);
109 pte = ptep_get(ptep);
110 WARN_ON(!pte_none(pte));
111
112 pte = pfn_pte(pfn, prot);
113 pte = pte_wrprotect(pte);
114 pte = pte_mkclean(pte);
115 set_pte_at(mm, vaddr, ptep, pte);
116 pte = pte_mkwrite(pte);
117 pte = pte_mkdirty(pte);
118 ptep_set_access_flags(vma, vaddr, ptep, pte, 1);
119 pte = ptep_get(ptep);
120 WARN_ON(!(pte_write(pte) && pte_dirty(pte)));
121 ptep_get_and_clear_full(mm, vaddr, ptep, 1);
122 pte = ptep_get(ptep);
123 WARN_ON(!pte_none(pte));
124
125 pte = pfn_pte(pfn, prot);
126 pte = pte_mkyoung(pte);
127 set_pte_at(mm, vaddr, ptep, pte);
128 ptep_test_and_clear_young(vma, vaddr, ptep);
129 pte = ptep_get(ptep);
130 WARN_ON(pte_young(pte));
131}
132
133static void __init pte_savedwrite_tests(unsigned long pfn, pgprot_t prot)
134{
135 pte_t pte = pfn_pte(pfn, prot);
136
137 if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
138 return;
139
140 pr_debug("Validating PTE saved write\n");
141 WARN_ON(!pte_savedwrite(pte_mk_savedwrite(pte_clear_savedwrite(pte))));
142 WARN_ON(pte_savedwrite(pte_clear_savedwrite(pte_mk_savedwrite(pte))));
143}
144
145#ifdef CONFIG_TRANSPARENT_HUGEPAGE
146static void __init pmd_basic_tests(unsigned long pfn, int idx)
147{
148 pgprot_t prot = protection_map[idx];
149 unsigned long val = idx, *ptr = &val;
150 pmd_t pmd;
151
152 if (!has_transparent_hugepage())
153 return;
154
155 pr_debug("Validating PMD basic (%pGv)\n", ptr);
156 pmd = pfn_pmd(pfn, prot);
157
158 /*
159 * This test needs to be executed after the given page table entry
160 * is created with pfn_pmd() to make sure that protection_map[idx]
161 * does not have the dirty bit enabled from the beginning. This is
162 * important for platforms like arm64 where (!PTE_RDONLY) indicate
163 * dirty bit being set.
164 */
165 WARN_ON(pmd_dirty(pmd_wrprotect(pmd)));
166
167
168 WARN_ON(!pmd_same(pmd, pmd));
169 WARN_ON(!pmd_young(pmd_mkyoung(pmd_mkold(pmd))));
170 WARN_ON(!pmd_dirty(pmd_mkdirty(pmd_mkclean(pmd))));
171 WARN_ON(!pmd_write(pmd_mkwrite(pmd_wrprotect(pmd))));
172 WARN_ON(pmd_young(pmd_mkold(pmd_mkyoung(pmd))));
173 WARN_ON(pmd_dirty(pmd_mkclean(pmd_mkdirty(pmd))));
174 WARN_ON(pmd_write(pmd_wrprotect(pmd_mkwrite(pmd))));
175 WARN_ON(pmd_dirty(pmd_wrprotect(pmd_mkclean(pmd))));
176 WARN_ON(!pmd_dirty(pmd_wrprotect(pmd_mkdirty(pmd))));
177 /*
178 * A huge page does not point to next level page table
179 * entry. Hence this must qualify as pmd_bad().
180 */
181 WARN_ON(!pmd_bad(pmd_mkhuge(pmd)));
182}
183
184static void __init pmd_advanced_tests(struct mm_struct *mm,
185 struct vm_area_struct *vma, pmd_t *pmdp,
186 unsigned long pfn, unsigned long vaddr,
187 pgprot_t prot, pgtable_t pgtable)
188{
189 pmd_t pmd;
190
191 if (!has_transparent_hugepage())
192 return;
193
194 pr_debug("Validating PMD advanced\n");
195 /* Align the address wrt HPAGE_PMD_SIZE */
196 vaddr &= HPAGE_PMD_MASK;
197
198 pgtable_trans_huge_deposit(mm, pmdp, pgtable);
199
200 pmd = pfn_pmd(pfn, prot);
201 set_pmd_at(mm, vaddr, pmdp, pmd);
202 pmdp_set_wrprotect(mm, vaddr, pmdp);
203 pmd = READ_ONCE(*pmdp);
204 WARN_ON(pmd_write(pmd));
205 pmdp_huge_get_and_clear(mm, vaddr, pmdp);
206 pmd = READ_ONCE(*pmdp);
207 WARN_ON(!pmd_none(pmd));
208
209 pmd = pfn_pmd(pfn, prot);
210 pmd = pmd_wrprotect(pmd);
211 pmd = pmd_mkclean(pmd);
212 set_pmd_at(mm, vaddr, pmdp, pmd);
213 pmd = pmd_mkwrite(pmd);
214 pmd = pmd_mkdirty(pmd);
215 pmdp_set_access_flags(vma, vaddr, pmdp, pmd, 1);
216 pmd = READ_ONCE(*pmdp);
217 WARN_ON(!(pmd_write(pmd) && pmd_dirty(pmd)));
218 pmdp_huge_get_and_clear_full(vma, vaddr, pmdp, 1);
219 pmd = READ_ONCE(*pmdp);
220 WARN_ON(!pmd_none(pmd));
221
222 pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
223 pmd = pmd_mkyoung(pmd);
224 set_pmd_at(mm, vaddr, pmdp, pmd);
225 pmdp_test_and_clear_young(vma, vaddr, pmdp);
226 pmd = READ_ONCE(*pmdp);
227 WARN_ON(pmd_young(pmd));
228
229 /* Clear the pte entries */
230 pmdp_huge_get_and_clear(mm, vaddr, pmdp);
231 pgtable = pgtable_trans_huge_withdraw(mm, pmdp);
232}
233
234static void __init pmd_leaf_tests(unsigned long pfn, pgprot_t prot)
235{
236 pmd_t pmd;
237
238 if (!has_transparent_hugepage())
239 return;
240
241 pr_debug("Validating PMD leaf\n");
242 pmd = pfn_pmd(pfn, prot);
243
244 /*
245 * PMD based THP is a leaf entry.
246 */
247 pmd = pmd_mkhuge(pmd);
248 WARN_ON(!pmd_leaf(pmd));
249}
250
251static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot)
252{
253 pmd_t pmd;
254
255 if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
256 return;
257
258 if (!has_transparent_hugepage())
259 return;
260
261 pr_debug("Validating PMD saved write\n");
262 pmd = pfn_pmd(pfn, prot);
263 WARN_ON(!pmd_savedwrite(pmd_mk_savedwrite(pmd_clear_savedwrite(pmd))));
264 WARN_ON(pmd_savedwrite(pmd_clear_savedwrite(pmd_mk_savedwrite(pmd))));
265}
266
267#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
268static void __init pud_basic_tests(struct mm_struct *mm, unsigned long pfn, int idx)
269{
270 pgprot_t prot = protection_map[idx];
271 unsigned long val = idx, *ptr = &val;
272 pud_t pud;
273
274 if (!has_transparent_hugepage())
275 return;
276
277 pr_debug("Validating PUD basic (%pGv)\n", ptr);
278 pud = pfn_pud(pfn, prot);
279
280 /*
281 * This test needs to be executed after the given page table entry
282 * is created with pfn_pud() to make sure that protection_map[idx]
283 * does not have the dirty bit enabled from the beginning. This is
284 * important for platforms like arm64 where (!PTE_RDONLY) indicate
285 * dirty bit being set.
286 */
287 WARN_ON(pud_dirty(pud_wrprotect(pud)));
288
289 WARN_ON(!pud_same(pud, pud));
290 WARN_ON(!pud_young(pud_mkyoung(pud_mkold(pud))));
291 WARN_ON(!pud_dirty(pud_mkdirty(pud_mkclean(pud))));
292 WARN_ON(pud_dirty(pud_mkclean(pud_mkdirty(pud))));
293 WARN_ON(!pud_write(pud_mkwrite(pud_wrprotect(pud))));
294 WARN_ON(pud_write(pud_wrprotect(pud_mkwrite(pud))));
295 WARN_ON(pud_young(pud_mkold(pud_mkyoung(pud))));
296 WARN_ON(pud_dirty(pud_wrprotect(pud_mkclean(pud))));
297 WARN_ON(!pud_dirty(pud_wrprotect(pud_mkdirty(pud))));
298
299 if (mm_pmd_folded(mm))
300 return;
301
302 /*
303 * A huge page does not point to next level page table
304 * entry. Hence this must qualify as pud_bad().
305 */
306 WARN_ON(!pud_bad(pud_mkhuge(pud)));
307}
308
309static void __init pud_advanced_tests(struct mm_struct *mm,
310 struct vm_area_struct *vma, pud_t *pudp,
311 unsigned long pfn, unsigned long vaddr,
312 pgprot_t prot)
313{
314 pud_t pud;
315
316 if (!has_transparent_hugepage())
317 return;
318
319 pr_debug("Validating PUD advanced\n");
320 /* Align the address wrt HPAGE_PUD_SIZE */
321 vaddr &= HPAGE_PUD_MASK;
322
323 pud = pfn_pud(pfn, prot);
324 set_pud_at(mm, vaddr, pudp, pud);
325 pudp_set_wrprotect(mm, vaddr, pudp);
326 pud = READ_ONCE(*pudp);
327 WARN_ON(pud_write(pud));
328
329#ifndef __PAGETABLE_PMD_FOLDED
330 pudp_huge_get_and_clear(mm, vaddr, pudp);
331 pud = READ_ONCE(*pudp);
332 WARN_ON(!pud_none(pud));
333#endif /* __PAGETABLE_PMD_FOLDED */
334 pud = pfn_pud(pfn, prot);
335 pud = pud_wrprotect(pud);
336 pud = pud_mkclean(pud);
337 set_pud_at(mm, vaddr, pudp, pud);
338 pud = pud_mkwrite(pud);
339 pud = pud_mkdirty(pud);
340 pudp_set_access_flags(vma, vaddr, pudp, pud, 1);
341 pud = READ_ONCE(*pudp);
342 WARN_ON(!(pud_write(pud) && pud_dirty(pud)));
343
344#ifndef __PAGETABLE_PMD_FOLDED
345 pudp_huge_get_and_clear_full(mm, vaddr, pudp, 1);
346 pud = READ_ONCE(*pudp);
347 WARN_ON(!pud_none(pud));
348#endif /* __PAGETABLE_PMD_FOLDED */
349
350 pud = pfn_pud(pfn, prot);
351 pud = pud_mkyoung(pud);
352 set_pud_at(mm, vaddr, pudp, pud);
353 pudp_test_and_clear_young(vma, vaddr, pudp);
354 pud = READ_ONCE(*pudp);
355 WARN_ON(pud_young(pud));
356
357 pudp_huge_get_and_clear(mm, vaddr, pudp);
358}
359
360static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot)
361{
362 pud_t pud;
363
364 if (!has_transparent_hugepage())
365 return;
366
367 pr_debug("Validating PUD leaf\n");
368 pud = pfn_pud(pfn, prot);
369 /*
370 * PUD based THP is a leaf entry.
371 */
372 pud = pud_mkhuge(pud);
373 WARN_ON(!pud_leaf(pud));
374}
375#else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
376static void __init pud_basic_tests(struct mm_struct *mm, unsigned long pfn, int idx) { }
377static void __init pud_advanced_tests(struct mm_struct *mm,
378 struct vm_area_struct *vma, pud_t *pudp,
379 unsigned long pfn, unsigned long vaddr,
380 pgprot_t prot)
381{
382}
383static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot) { }
384#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
385#else /* !CONFIG_TRANSPARENT_HUGEPAGE */
386static void __init pmd_basic_tests(unsigned long pfn, int idx) { }
387static void __init pud_basic_tests(struct mm_struct *mm, unsigned long pfn, int idx) { }
388static void __init pmd_advanced_tests(struct mm_struct *mm,
389 struct vm_area_struct *vma, pmd_t *pmdp,
390 unsigned long pfn, unsigned long vaddr,
391 pgprot_t prot, pgtable_t pgtable)
392{
393}
394static void __init pud_advanced_tests(struct mm_struct *mm,
395 struct vm_area_struct *vma, pud_t *pudp,
396 unsigned long pfn, unsigned long vaddr,
397 pgprot_t prot)
398{
399}
400static void __init pmd_leaf_tests(unsigned long pfn, pgprot_t prot) { }
401static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot) { }
402static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot) { }
403#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
404
405#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
406static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot)
407{
408 pmd_t pmd;
409
410 if (!arch_vmap_pmd_supported(prot))
411 return;
412
413 pr_debug("Validating PMD huge\n");
414 /*
415 * X86 defined pmd_set_huge() verifies that the given
416 * PMD is not a populated non-leaf entry.
417 */
418 WRITE_ONCE(*pmdp, __pmd(0));
419 WARN_ON(!pmd_set_huge(pmdp, __pfn_to_phys(pfn), prot));
420 WARN_ON(!pmd_clear_huge(pmdp));
421 pmd = READ_ONCE(*pmdp);
422 WARN_ON(!pmd_none(pmd));
423}
424
425static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot)
426{
427 pud_t pud;
428
429 if (!arch_vmap_pud_supported(prot))
430 return;
431
432 pr_debug("Validating PUD huge\n");
433 /*
434 * X86 defined pud_set_huge() verifies that the given
435 * PUD is not a populated non-leaf entry.
436 */
437 WRITE_ONCE(*pudp, __pud(0));
438 WARN_ON(!pud_set_huge(pudp, __pfn_to_phys(pfn), prot));
439 WARN_ON(!pud_clear_huge(pudp));
440 pud = READ_ONCE(*pudp);
441 WARN_ON(!pud_none(pud));
442}
443#else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
444static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot) { }
445static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot) { }
446#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
447
448static void __init p4d_basic_tests(unsigned long pfn, pgprot_t prot)
449{
450 p4d_t p4d;
451
452 pr_debug("Validating P4D basic\n");
453 memset(&p4d, RANDOM_NZVALUE, sizeof(p4d_t));
454 WARN_ON(!p4d_same(p4d, p4d));
455}
456
457static void __init pgd_basic_tests(unsigned long pfn, pgprot_t prot)
458{
459 pgd_t pgd;
460
461 pr_debug("Validating PGD basic\n");
462 memset(&pgd, RANDOM_NZVALUE, sizeof(pgd_t));
463 WARN_ON(!pgd_same(pgd, pgd));
464}
465
466#ifndef __PAGETABLE_PUD_FOLDED
467static void __init pud_clear_tests(struct mm_struct *mm, pud_t *pudp)
468{
469 pud_t pud = READ_ONCE(*pudp);
470
471 if (mm_pmd_folded(mm))
472 return;
473
474 pr_debug("Validating PUD clear\n");
475 pud = __pud(pud_val(pud) | RANDOM_ORVALUE);
476 WRITE_ONCE(*pudp, pud);
477 pud_clear(pudp);
478 pud = READ_ONCE(*pudp);
479 WARN_ON(!pud_none(pud));
480}
481
482static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp,
483 pmd_t *pmdp)
484{
485 pud_t pud;
486
487 if (mm_pmd_folded(mm))
488 return;
489
490 pr_debug("Validating PUD populate\n");
491 /*
492 * This entry points to next level page table page.
493 * Hence this must not qualify as pud_bad().
494 */
495 pud_populate(mm, pudp, pmdp);
496 pud = READ_ONCE(*pudp);
497 WARN_ON(pud_bad(pud));
498}
499#else /* !__PAGETABLE_PUD_FOLDED */
500static void __init pud_clear_tests(struct mm_struct *mm, pud_t *pudp) { }
501static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp,
502 pmd_t *pmdp)
503{
504}
505#endif /* PAGETABLE_PUD_FOLDED */
506
507#ifndef __PAGETABLE_P4D_FOLDED
508static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp)
509{
510 p4d_t p4d = READ_ONCE(*p4dp);
511
512 if (mm_pud_folded(mm))
513 return;
514
515 pr_debug("Validating P4D clear\n");
516 p4d = __p4d(p4d_val(p4d) | RANDOM_ORVALUE);
517 WRITE_ONCE(*p4dp, p4d);
518 p4d_clear(p4dp);
519 p4d = READ_ONCE(*p4dp);
520 WARN_ON(!p4d_none(p4d));
521}
522
523static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp,
524 pud_t *pudp)
525{
526 p4d_t p4d;
527
528 if (mm_pud_folded(mm))
529 return;
530
531 pr_debug("Validating P4D populate\n");
532 /*
533 * This entry points to next level page table page.
534 * Hence this must not qualify as p4d_bad().
535 */
536 pud_clear(pudp);
537 p4d_clear(p4dp);
538 p4d_populate(mm, p4dp, pudp);
539 p4d = READ_ONCE(*p4dp);
540 WARN_ON(p4d_bad(p4d));
541}
542
543static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp)
544{
545 pgd_t pgd = READ_ONCE(*pgdp);
546
547 if (mm_p4d_folded(mm))
548 return;
549
550 pr_debug("Validating PGD clear\n");
551 pgd = __pgd(pgd_val(pgd) | RANDOM_ORVALUE);
552 WRITE_ONCE(*pgdp, pgd);
553 pgd_clear(pgdp);
554 pgd = READ_ONCE(*pgdp);
555 WARN_ON(!pgd_none(pgd));
556}
557
558static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
559 p4d_t *p4dp)
560{
561 pgd_t pgd;
562
563 if (mm_p4d_folded(mm))
564 return;
565
566 pr_debug("Validating PGD populate\n");
567 /*
568 * This entry points to next level page table page.
569 * Hence this must not qualify as pgd_bad().
570 */
571 p4d_clear(p4dp);
572 pgd_clear(pgdp);
573 pgd_populate(mm, pgdp, p4dp);
574 pgd = READ_ONCE(*pgdp);
575 WARN_ON(pgd_bad(pgd));
576}
577#else /* !__PAGETABLE_P4D_FOLDED */
578static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp) { }
579static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp) { }
580static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp,
581 pud_t *pudp)
582{
583}
584static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
585 p4d_t *p4dp)
586{
587}
588#endif /* PAGETABLE_P4D_FOLDED */
589
590static void __init pte_clear_tests(struct mm_struct *mm, pte_t *ptep,
591 unsigned long pfn, unsigned long vaddr,
592 pgprot_t prot)
593{
594 pte_t pte = pfn_pte(pfn, prot);
595
596 pr_debug("Validating PTE clear\n");
597#ifndef CONFIG_RISCV
598 pte = __pte(pte_val(pte) | RANDOM_ORVALUE);
599#endif
600 set_pte_at(mm, vaddr, ptep, pte);
601 barrier();
602 pte_clear(mm, vaddr, ptep);
603 pte = ptep_get(ptep);
604 WARN_ON(!pte_none(pte));
605}
606
607static void __init pmd_clear_tests(struct mm_struct *mm, pmd_t *pmdp)
608{
609 pmd_t pmd = READ_ONCE(*pmdp);
610
611 pr_debug("Validating PMD clear\n");
612 pmd = __pmd(pmd_val(pmd) | RANDOM_ORVALUE);
613 WRITE_ONCE(*pmdp, pmd);
614 pmd_clear(pmdp);
615 pmd = READ_ONCE(*pmdp);
616 WARN_ON(!pmd_none(pmd));
617}
618
619static void __init pmd_populate_tests(struct mm_struct *mm, pmd_t *pmdp,
620 pgtable_t pgtable)
621{
622 pmd_t pmd;
623
624 pr_debug("Validating PMD populate\n");
625 /*
626 * This entry points to next level page table page.
627 * Hence this must not qualify as pmd_bad().
628 */
629 pmd_populate(mm, pmdp, pgtable);
630 pmd = READ_ONCE(*pmdp);
631 WARN_ON(pmd_bad(pmd));
632}
633
634static void __init pte_special_tests(unsigned long pfn, pgprot_t prot)
635{
636 pte_t pte = pfn_pte(pfn, prot);
637
638 if (!IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL))
639 return;
640
641 pr_debug("Validating PTE special\n");
642 WARN_ON(!pte_special(pte_mkspecial(pte)));
643}
644
645static void __init pte_protnone_tests(unsigned long pfn, pgprot_t prot)
646{
647 pte_t pte = pfn_pte(pfn, prot);
648
649 if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
650 return;
651
652 pr_debug("Validating PTE protnone\n");
653 WARN_ON(!pte_protnone(pte));
654 WARN_ON(!pte_present(pte));
655}
656
657#ifdef CONFIG_TRANSPARENT_HUGEPAGE
658static void __init pmd_protnone_tests(unsigned long pfn, pgprot_t prot)
659{
660 pmd_t pmd;
661
662 if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
663 return;
664
665 if (!has_transparent_hugepage())
666 return;
667
668 pr_debug("Validating PMD protnone\n");
669 pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
670 WARN_ON(!pmd_protnone(pmd));
671 WARN_ON(!pmd_present(pmd));
672}
673#else /* !CONFIG_TRANSPARENT_HUGEPAGE */
674static void __init pmd_protnone_tests(unsigned long pfn, pgprot_t prot) { }
675#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
676
677#ifdef CONFIG_ARCH_HAS_PTE_DEVMAP
678static void __init pte_devmap_tests(unsigned long pfn, pgprot_t prot)
679{
680 pte_t pte = pfn_pte(pfn, prot);
681
682 pr_debug("Validating PTE devmap\n");
683 WARN_ON(!pte_devmap(pte_mkdevmap(pte)));
684}
685
686#ifdef CONFIG_TRANSPARENT_HUGEPAGE
687static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot)
688{
689 pmd_t pmd;
690
691 if (!has_transparent_hugepage())
692 return;
693
694 pr_debug("Validating PMD devmap\n");
695 pmd = pfn_pmd(pfn, prot);
696 WARN_ON(!pmd_devmap(pmd_mkdevmap(pmd)));
697}
698
699#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
700static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot)
701{
702 pud_t pud;
703
704 if (!has_transparent_hugepage())
705 return;
706
707 pr_debug("Validating PUD devmap\n");
708 pud = pfn_pud(pfn, prot);
709 WARN_ON(!pud_devmap(pud_mkdevmap(pud)));
710}
711#else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
712static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) { }
713#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
714#else /* CONFIG_TRANSPARENT_HUGEPAGE */
715static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot) { }
716static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) { }
717#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
718#else
719static void __init pte_devmap_tests(unsigned long pfn, pgprot_t prot) { }
720static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot) { }
721static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) { }
722#endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */
723
724static void __init pte_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
725{
726 pte_t pte = pfn_pte(pfn, prot);
727
728 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
729 return;
730
731 pr_debug("Validating PTE soft dirty\n");
732 WARN_ON(!pte_soft_dirty(pte_mksoft_dirty(pte)));
733 WARN_ON(pte_soft_dirty(pte_clear_soft_dirty(pte)));
734}
735
736static void __init pte_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
737{
738 pte_t pte = pfn_pte(pfn, prot);
739
740 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
741 return;
742
743 pr_debug("Validating PTE swap soft dirty\n");
744 WARN_ON(!pte_swp_soft_dirty(pte_swp_mksoft_dirty(pte)));
745 WARN_ON(pte_swp_soft_dirty(pte_swp_clear_soft_dirty(pte)));
746}
747
748#ifdef CONFIG_TRANSPARENT_HUGEPAGE
749static void __init pmd_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
750{
751 pmd_t pmd;
752
753 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
754 return;
755
756 if (!has_transparent_hugepage())
757 return;
758
759 pr_debug("Validating PMD soft dirty\n");
760 pmd = pfn_pmd(pfn, prot);
761 WARN_ON(!pmd_soft_dirty(pmd_mksoft_dirty(pmd)));
762 WARN_ON(pmd_soft_dirty(pmd_clear_soft_dirty(pmd)));
763}
764
765static void __init pmd_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
766{
767 pmd_t pmd;
768
769 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY) ||
770 !IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION))
771 return;
772
773 if (!has_transparent_hugepage())
774 return;
775
776 pr_debug("Validating PMD swap soft dirty\n");
777 pmd = pfn_pmd(pfn, prot);
778 WARN_ON(!pmd_swp_soft_dirty(pmd_swp_mksoft_dirty(pmd)));
779 WARN_ON(pmd_swp_soft_dirty(pmd_swp_clear_soft_dirty(pmd)));
780}
781#else /* !CONFIG_TRANSPARENT_HUGEPAGE */
782static void __init pmd_soft_dirty_tests(unsigned long pfn, pgprot_t prot) { }
783static void __init pmd_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
784{
785}
786#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
787
788static void __init pte_swap_tests(unsigned long pfn, pgprot_t prot)
789{
790 swp_entry_t swp;
791 pte_t pte;
792
793 pr_debug("Validating PTE swap\n");
794 pte = pfn_pte(pfn, prot);
795 swp = __pte_to_swp_entry(pte);
796 pte = __swp_entry_to_pte(swp);
797 WARN_ON(pfn != pte_pfn(pte));
798}
799
800#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
801static void __init pmd_swap_tests(unsigned long pfn, pgprot_t prot)
802{
803 swp_entry_t swp;
804 pmd_t pmd;
805
806 if (!has_transparent_hugepage())
807 return;
808
809 pr_debug("Validating PMD swap\n");
810 pmd = pfn_pmd(pfn, prot);
811 swp = __pmd_to_swp_entry(pmd);
812 pmd = __swp_entry_to_pmd(swp);
813 WARN_ON(pfn != pmd_pfn(pmd));
814}
815#else /* !CONFIG_ARCH_ENABLE_THP_MIGRATION */
816static void __init pmd_swap_tests(unsigned long pfn, pgprot_t prot) { }
817#endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
818
819static void __init swap_migration_tests(void)
820{
821 struct page *page;
822 swp_entry_t swp;
823
824 if (!IS_ENABLED(CONFIG_MIGRATION))
825 return;
826
827 pr_debug("Validating swap migration\n");
828 /*
829 * swap_migration_tests() requires a dedicated page as it needs to
830 * be locked before creating a migration entry from it. Locking the
831 * page that actually maps kernel text ('start_kernel') can be real
832 * problematic. Lets allocate a dedicated page explicitly for this
833 * purpose that will be freed subsequently.
834 */
835 page = alloc_page(GFP_KERNEL);
836 if (!page) {
837 pr_err("page allocation failed\n");
838 return;
839 }
840
841 /*
842 * make_migration_entry() expects given page to be
843 * locked, otherwise it stumbles upon a BUG_ON().
844 */
845 __SetPageLocked(page);
846 swp = make_writable_migration_entry(page_to_pfn(page));
847 WARN_ON(!is_migration_entry(swp));
848 WARN_ON(!is_writable_migration_entry(swp));
849
850 swp = make_readable_migration_entry(swp_offset(swp));
851 WARN_ON(!is_migration_entry(swp));
852 WARN_ON(is_writable_migration_entry(swp));
853
854 swp = make_readable_migration_entry(page_to_pfn(page));
855 WARN_ON(!is_migration_entry(swp));
856 WARN_ON(is_writable_migration_entry(swp));
857 __ClearPageLocked(page);
858 __free_page(page);
859}
860
861#ifdef CONFIG_HUGETLB_PAGE
862static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot)
863{
864 struct page *page;
865 pte_t pte;
866
867 pr_debug("Validating HugeTLB basic\n");
868 /*
869 * Accessing the page associated with the pfn is safe here,
870 * as it was previously derived from a real kernel symbol.
871 */
872 page = pfn_to_page(pfn);
873 pte = mk_huge_pte(page, prot);
874
875 WARN_ON(!huge_pte_dirty(huge_pte_mkdirty(pte)));
876 WARN_ON(!huge_pte_write(huge_pte_mkwrite(huge_pte_wrprotect(pte))));
877 WARN_ON(huge_pte_write(huge_pte_wrprotect(huge_pte_mkwrite(pte))));
878
879#ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB
880 pte = pfn_pte(pfn, prot);
881
882 WARN_ON(!pte_huge(pte_mkhuge(pte)));
883#endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */
884}
885#else /* !CONFIG_HUGETLB_PAGE */
886static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot) { }
887#endif /* CONFIG_HUGETLB_PAGE */
888
889#ifdef CONFIG_TRANSPARENT_HUGEPAGE
890static void __init pmd_thp_tests(unsigned long pfn, pgprot_t prot)
891{
892 pmd_t pmd;
893
894 if (!has_transparent_hugepage())
895 return;
896
897 pr_debug("Validating PMD based THP\n");
898 /*
899 * pmd_trans_huge() and pmd_present() must return positive after
900 * MMU invalidation with pmd_mkinvalid(). This behavior is an
901 * optimization for transparent huge page. pmd_trans_huge() must
902 * be true if pmd_page() returns a valid THP to avoid taking the
903 * pmd_lock when others walk over non transhuge pmds (i.e. there
904 * are no THP allocated). Especially when splitting a THP and
905 * removing the present bit from the pmd, pmd_trans_huge() still
906 * needs to return true. pmd_present() should be true whenever
907 * pmd_trans_huge() returns true.
908 */
909 pmd = pfn_pmd(pfn, prot);
910 WARN_ON(!pmd_trans_huge(pmd_mkhuge(pmd)));
911
912#ifndef __HAVE_ARCH_PMDP_INVALIDATE
913 WARN_ON(!pmd_trans_huge(pmd_mkinvalid(pmd_mkhuge(pmd))));
914 WARN_ON(!pmd_present(pmd_mkinvalid(pmd_mkhuge(pmd))));
915#endif /* __HAVE_ARCH_PMDP_INVALIDATE */
916}
917
918#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
919static void __init pud_thp_tests(unsigned long pfn, pgprot_t prot)
920{
921 pud_t pud;
922
923 if (!has_transparent_hugepage())
924 return;
925
926 pr_debug("Validating PUD based THP\n");
927 pud = pfn_pud(pfn, prot);
928 WARN_ON(!pud_trans_huge(pud_mkhuge(pud)));
929
930 /*
931 * pud_mkinvalid() has been dropped for now. Enable back
932 * these tests when it comes back with a modified pud_present().
933 *
934 * WARN_ON(!pud_trans_huge(pud_mkinvalid(pud_mkhuge(pud))));
935 * WARN_ON(!pud_present(pud_mkinvalid(pud_mkhuge(pud))));
936 */
937}
938#else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
939static void __init pud_thp_tests(unsigned long pfn, pgprot_t prot) { }
940#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
941#else /* !CONFIG_TRANSPARENT_HUGEPAGE */
942static void __init pmd_thp_tests(unsigned long pfn, pgprot_t prot) { }
943static void __init pud_thp_tests(unsigned long pfn, pgprot_t prot) { }
944#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
945
946static unsigned long __init get_random_vaddr(void)
947{
948 unsigned long random_vaddr, random_pages, total_user_pages;
949
950 total_user_pages = (TASK_SIZE - FIRST_USER_ADDRESS) / PAGE_SIZE;
951
952 random_pages = get_random_long() % total_user_pages;
953 random_vaddr = FIRST_USER_ADDRESS + random_pages * PAGE_SIZE;
954
955 return random_vaddr;
956}
957
958static int __init debug_vm_pgtable(void)
959{
960 struct vm_area_struct *vma;
961 struct mm_struct *mm;
962 pgd_t *pgdp;
963 p4d_t *p4dp, *saved_p4dp;
964 pud_t *pudp, *saved_pudp;
965 pmd_t *pmdp, *saved_pmdp, pmd;
966 pte_t *ptep;
967 pgtable_t saved_ptep;
968 pgprot_t prot, protnone;
969 phys_addr_t paddr;
970 unsigned long vaddr, pte_aligned, pmd_aligned;
971 unsigned long pud_aligned, p4d_aligned, pgd_aligned;
972 spinlock_t *ptl = NULL;
973 int idx;
974
975 pr_info("Validating architecture page table helpers\n");
976 prot = vm_get_page_prot(VMFLAGS);
977 vaddr = get_random_vaddr();
978 mm = mm_alloc();
979 if (!mm) {
980 pr_err("mm_struct allocation failed\n");
981 return 1;
982 }
983
984 /*
985 * __P000 (or even __S000) will help create page table entries with
986 * PROT_NONE permission as required for pxx_protnone_tests().
987 */
988 protnone = __P000;
989
990 vma = vm_area_alloc(mm);
991 if (!vma) {
992 pr_err("vma allocation failed\n");
993 return 1;
994 }
995
996 /*
997 * PFN for mapping at PTE level is determined from a standard kernel
998 * text symbol. But pfns for higher page table levels are derived by
999 * masking lower bits of this real pfn. These derived pfns might not
1000 * exist on the platform but that does not really matter as pfn_pxx()
1001 * helpers will still create appropriate entries for the test. This
1002 * helps avoid large memory block allocations to be used for mapping
1003 * at higher page table levels.
1004 */
1005 paddr = __pa_symbol(&start_kernel);
1006
1007 pte_aligned = (paddr & PAGE_MASK) >> PAGE_SHIFT;
1008 pmd_aligned = (paddr & PMD_MASK) >> PAGE_SHIFT;
1009 pud_aligned = (paddr & PUD_MASK) >> PAGE_SHIFT;
1010 p4d_aligned = (paddr & P4D_MASK) >> PAGE_SHIFT;
1011 pgd_aligned = (paddr & PGDIR_MASK) >> PAGE_SHIFT;
1012 WARN_ON(!pfn_valid(pte_aligned));
1013
1014 pgdp = pgd_offset(mm, vaddr);
1015 p4dp = p4d_alloc(mm, pgdp, vaddr);
1016 pudp = pud_alloc(mm, p4dp, vaddr);
1017 pmdp = pmd_alloc(mm, pudp, vaddr);
1018 /*
1019 * Allocate pgtable_t
1020 */
1021 if (pte_alloc(mm, pmdp)) {
1022 pr_err("pgtable allocation failed\n");
1023 return 1;
1024 }
1025
1026 /*
1027 * Save all the page table page addresses as the page table
1028 * entries will be used for testing with random or garbage
1029 * values. These saved addresses will be used for freeing
1030 * page table pages.
1031 */
1032 pmd = READ_ONCE(*pmdp);
1033 saved_p4dp = p4d_offset(pgdp, 0UL);
1034 saved_pudp = pud_offset(p4dp, 0UL);
1035 saved_pmdp = pmd_offset(pudp, 0UL);
1036 saved_ptep = pmd_pgtable(pmd);
1037
1038 /*
1039 * Iterate over the protection_map[] to make sure that all
1040 * the basic page table transformation validations just hold
1041 * true irrespective of the starting protection value for a
1042 * given page table entry.
1043 */
1044 for (idx = 0; idx < ARRAY_SIZE(protection_map); idx++) {
1045 pte_basic_tests(pte_aligned, idx);
1046 pmd_basic_tests(pmd_aligned, idx);
1047 pud_basic_tests(mm, pud_aligned, idx);
1048 }
1049
1050 /*
1051 * Both P4D and PGD level tests are very basic which do not
1052 * involve creating page table entries from the protection
1053 * value and the given pfn. Hence just keep them out from
1054 * the above iteration for now to save some test execution
1055 * time.
1056 */
1057 p4d_basic_tests(p4d_aligned, prot);
1058 pgd_basic_tests(pgd_aligned, prot);
1059
1060 pmd_leaf_tests(pmd_aligned, prot);
1061 pud_leaf_tests(pud_aligned, prot);
1062
1063 pte_savedwrite_tests(pte_aligned, protnone);
1064 pmd_savedwrite_tests(pmd_aligned, protnone);
1065
1066 pte_special_tests(pte_aligned, prot);
1067 pte_protnone_tests(pte_aligned, protnone);
1068 pmd_protnone_tests(pmd_aligned, protnone);
1069
1070 pte_devmap_tests(pte_aligned, prot);
1071 pmd_devmap_tests(pmd_aligned, prot);
1072 pud_devmap_tests(pud_aligned, prot);
1073
1074 pte_soft_dirty_tests(pte_aligned, prot);
1075 pmd_soft_dirty_tests(pmd_aligned, prot);
1076 pte_swap_soft_dirty_tests(pte_aligned, prot);
1077 pmd_swap_soft_dirty_tests(pmd_aligned, prot);
1078
1079 pte_swap_tests(pte_aligned, prot);
1080 pmd_swap_tests(pmd_aligned, prot);
1081
1082 swap_migration_tests();
1083
1084 pmd_thp_tests(pmd_aligned, prot);
1085 pud_thp_tests(pud_aligned, prot);
1086
1087 hugetlb_basic_tests(pte_aligned, prot);
1088
1089 /*
1090 * Page table modifying tests. They need to hold
1091 * proper page table lock.
1092 */
1093
1094 ptep = pte_offset_map_lock(mm, pmdp, vaddr, &ptl);
1095 pte_clear_tests(mm, ptep, pte_aligned, vaddr, prot);
1096 pte_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot);
1097 pte_unmap_unlock(ptep, ptl);
1098
1099 ptl = pmd_lock(mm, pmdp);
1100 pmd_clear_tests(mm, pmdp);
1101 pmd_advanced_tests(mm, vma, pmdp, pmd_aligned, vaddr, prot, saved_ptep);
1102 pmd_huge_tests(pmdp, pmd_aligned, prot);
1103 pmd_populate_tests(mm, pmdp, saved_ptep);
1104 spin_unlock(ptl);
1105
1106 ptl = pud_lock(mm, pudp);
1107 pud_clear_tests(mm, pudp);
1108 pud_advanced_tests(mm, vma, pudp, pud_aligned, vaddr, prot);
1109 pud_huge_tests(pudp, pud_aligned, prot);
1110 pud_populate_tests(mm, pudp, saved_pmdp);
1111 spin_unlock(ptl);
1112
1113 spin_lock(&mm->page_table_lock);
1114 p4d_clear_tests(mm, p4dp);
1115 pgd_clear_tests(mm, pgdp);
1116 p4d_populate_tests(mm, p4dp, saved_pudp);
1117 pgd_populate_tests(mm, pgdp, saved_p4dp);
1118 spin_unlock(&mm->page_table_lock);
1119
1120 p4d_free(mm, saved_p4dp);
1121 pud_free(mm, saved_pudp);
1122 pmd_free(mm, saved_pmdp);
1123 pte_free(mm, saved_ptep);
1124
1125 vm_area_free(vma);
1126 mm_dec_nr_puds(mm);
1127 mm_dec_nr_pmds(mm);
1128 mm_dec_nr_ptes(mm);
1129 mmdrop(mm);
1130 return 0;
1131}
1132late_initcall(debug_vm_pgtable);