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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/memblock.h>
19#include <linux/mm.h>
20#include <linux/mman.h>
21#include <linux/mm_types.h>
22#include <linux/module.h>
23#include <linux/pfn_t.h>
24#include <linux/printk.h>
25#include <linux/pgtable.h>
26#include <linux/random.h>
27#include <linux/spinlock.h>
28#include <linux/swap.h>
29#include <linux/swapops.h>
30#include <linux/start_kernel.h>
31#include <linux/sched/mm.h>
32#include <linux/io.h>
33
34#include <asm/cacheflush.h>
35#include <asm/pgalloc.h>
36#include <asm/tlbflush.h>
37
38/*
39 * Please refer Documentation/mm/arch_pgtable_helpers.rst for the semantics
40 * expectations that are being validated here. All future changes in here
41 * or the documentation need to be in sync.
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. Also avoid the 62nd bit on ppc64 that is
48 * used to mark a pte entry.
49 */
50#define S390_SKIP_MASK GENMASK(3, 0)
51#if __BITS_PER_LONG == 64
52#define PPC64_SKIP_MASK GENMASK(62, 62)
53#else
54#define PPC64_SKIP_MASK 0x0
55#endif
56#define ARCH_SKIP_MASK (S390_SKIP_MASK | PPC64_SKIP_MASK)
57#define RANDOM_ORVALUE (GENMASK(BITS_PER_LONG - 1, 0) & ~ARCH_SKIP_MASK)
58#define RANDOM_NZVALUE GENMASK(7, 0)
59
60struct pgtable_debug_args {
61 struct mm_struct *mm;
62 struct vm_area_struct *vma;
63
64 pgd_t *pgdp;
65 p4d_t *p4dp;
66 pud_t *pudp;
67 pmd_t *pmdp;
68 pte_t *ptep;
69
70 p4d_t *start_p4dp;
71 pud_t *start_pudp;
72 pmd_t *start_pmdp;
73 pgtable_t start_ptep;
74
75 unsigned long vaddr;
76 pgprot_t page_prot;
77 pgprot_t page_prot_none;
78
79 bool is_contiguous_page;
80 unsigned long pud_pfn;
81 unsigned long pmd_pfn;
82 unsigned long pte_pfn;
83
84 unsigned long fixed_alignment;
85 unsigned long fixed_pgd_pfn;
86 unsigned long fixed_p4d_pfn;
87 unsigned long fixed_pud_pfn;
88 unsigned long fixed_pmd_pfn;
89 unsigned long fixed_pte_pfn;
90};
91
92static void __init pte_basic_tests(struct pgtable_debug_args *args, int idx)
93{
94 pgprot_t prot = vm_get_page_prot(idx);
95 pte_t pte = pfn_pte(args->fixed_pte_pfn, prot);
96 unsigned long val = idx, *ptr = &val;
97
98 pr_debug("Validating PTE basic (%pGv)\n", ptr);
99
100 /*
101 * This test needs to be executed after the given page table entry
102 * is created with pfn_pte() to make sure that vm_get_page_prot(idx)
103 * does not have the dirty bit enabled from the beginning. This is
104 * important for platforms like arm64 where (!PTE_RDONLY) indicate
105 * dirty bit being set.
106 */
107 WARN_ON(pte_dirty(pte_wrprotect(pte)));
108
109 WARN_ON(!pte_same(pte, pte));
110 WARN_ON(!pte_young(pte_mkyoung(pte_mkold(pte))));
111 WARN_ON(!pte_dirty(pte_mkdirty(pte_mkclean(pte))));
112 WARN_ON(!pte_write(pte_mkwrite(pte_wrprotect(pte), args->vma)));
113 WARN_ON(pte_young(pte_mkold(pte_mkyoung(pte))));
114 WARN_ON(pte_dirty(pte_mkclean(pte_mkdirty(pte))));
115 WARN_ON(pte_write(pte_wrprotect(pte_mkwrite(pte, args->vma))));
116 WARN_ON(pte_dirty(pte_wrprotect(pte_mkclean(pte))));
117 WARN_ON(!pte_dirty(pte_wrprotect(pte_mkdirty(pte))));
118}
119
120static void __init pte_advanced_tests(struct pgtable_debug_args *args)
121{
122 struct page *page;
123 pte_t pte;
124
125 /*
126 * Architectures optimize set_pte_at by avoiding TLB flush.
127 * This requires set_pte_at to be not used to update an
128 * existing pte entry. Clear pte before we do set_pte_at
129 *
130 * flush_dcache_page() is called after set_pte_at() to clear
131 * PG_arch_1 for the page on ARM64. The page flag isn't cleared
132 * when it's released and page allocation check will fail when
133 * the page is allocated again. For architectures other than ARM64,
134 * the unexpected overhead of cache flushing is acceptable.
135 */
136 page = (args->pte_pfn != ULONG_MAX) ? pfn_to_page(args->pte_pfn) : NULL;
137 if (!page)
138 return;
139
140 pr_debug("Validating PTE advanced\n");
141 if (WARN_ON(!args->ptep))
142 return;
143
144 pte = pfn_pte(args->pte_pfn, args->page_prot);
145 set_pte_at(args->mm, args->vaddr, args->ptep, pte);
146 flush_dcache_page(page);
147 ptep_set_wrprotect(args->mm, args->vaddr, args->ptep);
148 pte = ptep_get(args->ptep);
149 WARN_ON(pte_write(pte));
150 ptep_get_and_clear(args->mm, args->vaddr, args->ptep);
151 pte = ptep_get(args->ptep);
152 WARN_ON(!pte_none(pte));
153
154 pte = pfn_pte(args->pte_pfn, args->page_prot);
155 pte = pte_wrprotect(pte);
156 pte = pte_mkclean(pte);
157 set_pte_at(args->mm, args->vaddr, args->ptep, pte);
158 flush_dcache_page(page);
159 pte = pte_mkwrite(pte, args->vma);
160 pte = pte_mkdirty(pte);
161 ptep_set_access_flags(args->vma, args->vaddr, args->ptep, pte, 1);
162 pte = ptep_get(args->ptep);
163 WARN_ON(!(pte_write(pte) && pte_dirty(pte)));
164 ptep_get_and_clear_full(args->mm, args->vaddr, args->ptep, 1);
165 pte = ptep_get(args->ptep);
166 WARN_ON(!pte_none(pte));
167
168 pte = pfn_pte(args->pte_pfn, args->page_prot);
169 pte = pte_mkyoung(pte);
170 set_pte_at(args->mm, args->vaddr, args->ptep, pte);
171 flush_dcache_page(page);
172 ptep_test_and_clear_young(args->vma, args->vaddr, args->ptep);
173 pte = ptep_get(args->ptep);
174 WARN_ON(pte_young(pte));
175
176 ptep_get_and_clear_full(args->mm, args->vaddr, args->ptep, 1);
177}
178
179#ifdef CONFIG_TRANSPARENT_HUGEPAGE
180static void __init pmd_basic_tests(struct pgtable_debug_args *args, int idx)
181{
182 pgprot_t prot = vm_get_page_prot(idx);
183 unsigned long val = idx, *ptr = &val;
184 pmd_t pmd;
185
186 if (!has_transparent_hugepage())
187 return;
188
189 pr_debug("Validating PMD basic (%pGv)\n", ptr);
190 pmd = pfn_pmd(args->fixed_pmd_pfn, prot);
191
192 /*
193 * This test needs to be executed after the given page table entry
194 * is created with pfn_pmd() to make sure that vm_get_page_prot(idx)
195 * does not have the dirty bit enabled from the beginning. This is
196 * important for platforms like arm64 where (!PTE_RDONLY) indicate
197 * dirty bit being set.
198 */
199 WARN_ON(pmd_dirty(pmd_wrprotect(pmd)));
200
201
202 WARN_ON(!pmd_same(pmd, pmd));
203 WARN_ON(!pmd_young(pmd_mkyoung(pmd_mkold(pmd))));
204 WARN_ON(!pmd_dirty(pmd_mkdirty(pmd_mkclean(pmd))));
205 WARN_ON(!pmd_write(pmd_mkwrite(pmd_wrprotect(pmd), args->vma)));
206 WARN_ON(pmd_young(pmd_mkold(pmd_mkyoung(pmd))));
207 WARN_ON(pmd_dirty(pmd_mkclean(pmd_mkdirty(pmd))));
208 WARN_ON(pmd_write(pmd_wrprotect(pmd_mkwrite(pmd, args->vma))));
209 WARN_ON(pmd_dirty(pmd_wrprotect(pmd_mkclean(pmd))));
210 WARN_ON(!pmd_dirty(pmd_wrprotect(pmd_mkdirty(pmd))));
211 /*
212 * A huge page does not point to next level page table
213 * entry. Hence this must qualify as pmd_bad().
214 */
215 WARN_ON(!pmd_bad(pmd_mkhuge(pmd)));
216}
217
218static void __init pmd_advanced_tests(struct pgtable_debug_args *args)
219{
220 struct page *page;
221 pmd_t pmd;
222 unsigned long vaddr = args->vaddr;
223
224 if (!has_transparent_hugepage())
225 return;
226
227 page = (args->pmd_pfn != ULONG_MAX) ? pfn_to_page(args->pmd_pfn) : NULL;
228 if (!page)
229 return;
230
231 /*
232 * flush_dcache_page() is called after set_pmd_at() to clear
233 * PG_arch_1 for the page on ARM64. The page flag isn't cleared
234 * when it's released and page allocation check will fail when
235 * the page is allocated again. For architectures other than ARM64,
236 * the unexpected overhead of cache flushing is acceptable.
237 */
238 pr_debug("Validating PMD advanced\n");
239 /* Align the address wrt HPAGE_PMD_SIZE */
240 vaddr &= HPAGE_PMD_MASK;
241
242 pgtable_trans_huge_deposit(args->mm, args->pmdp, args->start_ptep);
243
244 pmd = pfn_pmd(args->pmd_pfn, args->page_prot);
245 set_pmd_at(args->mm, vaddr, args->pmdp, pmd);
246 flush_dcache_page(page);
247 pmdp_set_wrprotect(args->mm, vaddr, args->pmdp);
248 pmd = READ_ONCE(*args->pmdp);
249 WARN_ON(pmd_write(pmd));
250 pmdp_huge_get_and_clear(args->mm, vaddr, args->pmdp);
251 pmd = READ_ONCE(*args->pmdp);
252 WARN_ON(!pmd_none(pmd));
253
254 pmd = pfn_pmd(args->pmd_pfn, args->page_prot);
255 pmd = pmd_wrprotect(pmd);
256 pmd = pmd_mkclean(pmd);
257 set_pmd_at(args->mm, vaddr, args->pmdp, pmd);
258 flush_dcache_page(page);
259 pmd = pmd_mkwrite(pmd, args->vma);
260 pmd = pmd_mkdirty(pmd);
261 pmdp_set_access_flags(args->vma, vaddr, args->pmdp, pmd, 1);
262 pmd = READ_ONCE(*args->pmdp);
263 WARN_ON(!(pmd_write(pmd) && pmd_dirty(pmd)));
264 pmdp_huge_get_and_clear_full(args->vma, vaddr, args->pmdp, 1);
265 pmd = READ_ONCE(*args->pmdp);
266 WARN_ON(!pmd_none(pmd));
267
268 pmd = pmd_mkhuge(pfn_pmd(args->pmd_pfn, args->page_prot));
269 pmd = pmd_mkyoung(pmd);
270 set_pmd_at(args->mm, vaddr, args->pmdp, pmd);
271 flush_dcache_page(page);
272 pmdp_test_and_clear_young(args->vma, vaddr, args->pmdp);
273 pmd = READ_ONCE(*args->pmdp);
274 WARN_ON(pmd_young(pmd));
275
276 /* Clear the pte entries */
277 pmdp_huge_get_and_clear(args->mm, vaddr, args->pmdp);
278 pgtable_trans_huge_withdraw(args->mm, args->pmdp);
279}
280
281static void __init pmd_leaf_tests(struct pgtable_debug_args *args)
282{
283 pmd_t pmd;
284
285 if (!has_transparent_hugepage())
286 return;
287
288 pr_debug("Validating PMD leaf\n");
289 pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot);
290
291 /*
292 * PMD based THP is a leaf entry.
293 */
294 pmd = pmd_mkhuge(pmd);
295 WARN_ON(!pmd_leaf(pmd));
296}
297
298#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
299static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx)
300{
301 pgprot_t prot = vm_get_page_prot(idx);
302 unsigned long val = idx, *ptr = &val;
303 pud_t pud;
304
305 if (!has_transparent_pud_hugepage())
306 return;
307
308 pr_debug("Validating PUD basic (%pGv)\n", ptr);
309 pud = pfn_pud(args->fixed_pud_pfn, prot);
310
311 /*
312 * This test needs to be executed after the given page table entry
313 * is created with pfn_pud() to make sure that vm_get_page_prot(idx)
314 * does not have the dirty bit enabled from the beginning. This is
315 * important for platforms like arm64 where (!PTE_RDONLY) indicate
316 * dirty bit being set.
317 */
318 WARN_ON(pud_dirty(pud_wrprotect(pud)));
319
320 WARN_ON(!pud_same(pud, pud));
321 WARN_ON(!pud_young(pud_mkyoung(pud_mkold(pud))));
322 WARN_ON(!pud_dirty(pud_mkdirty(pud_mkclean(pud))));
323 WARN_ON(pud_dirty(pud_mkclean(pud_mkdirty(pud))));
324 WARN_ON(!pud_write(pud_mkwrite(pud_wrprotect(pud))));
325 WARN_ON(pud_write(pud_wrprotect(pud_mkwrite(pud))));
326 WARN_ON(pud_young(pud_mkold(pud_mkyoung(pud))));
327 WARN_ON(pud_dirty(pud_wrprotect(pud_mkclean(pud))));
328 WARN_ON(!pud_dirty(pud_wrprotect(pud_mkdirty(pud))));
329
330 if (mm_pmd_folded(args->mm))
331 return;
332
333 /*
334 * A huge page does not point to next level page table
335 * entry. Hence this must qualify as pud_bad().
336 */
337 WARN_ON(!pud_bad(pud_mkhuge(pud)));
338}
339
340static void __init pud_advanced_tests(struct pgtable_debug_args *args)
341{
342 struct page *page;
343 unsigned long vaddr = args->vaddr;
344 pud_t pud;
345
346 if (!has_transparent_pud_hugepage())
347 return;
348
349 page = (args->pud_pfn != ULONG_MAX) ? pfn_to_page(args->pud_pfn) : NULL;
350 if (!page)
351 return;
352
353 /*
354 * flush_dcache_page() is called after set_pud_at() to clear
355 * PG_arch_1 for the page on ARM64. The page flag isn't cleared
356 * when it's released and page allocation check will fail when
357 * the page is allocated again. For architectures other than ARM64,
358 * the unexpected overhead of cache flushing is acceptable.
359 */
360 pr_debug("Validating PUD advanced\n");
361 /* Align the address wrt HPAGE_PUD_SIZE */
362 vaddr &= HPAGE_PUD_MASK;
363
364 pud = pfn_pud(args->pud_pfn, args->page_prot);
365 /*
366 * Some architectures have debug checks to make sure
367 * huge pud mapping are only found with devmap entries
368 * For now test with only devmap entries.
369 */
370 pud = pud_mkdevmap(pud);
371 set_pud_at(args->mm, vaddr, args->pudp, pud);
372 flush_dcache_page(page);
373 pudp_set_wrprotect(args->mm, vaddr, args->pudp);
374 pud = READ_ONCE(*args->pudp);
375 WARN_ON(pud_write(pud));
376
377#ifndef __PAGETABLE_PMD_FOLDED
378 pudp_huge_get_and_clear(args->mm, vaddr, args->pudp);
379 pud = READ_ONCE(*args->pudp);
380 WARN_ON(!pud_none(pud));
381#endif /* __PAGETABLE_PMD_FOLDED */
382 pud = pfn_pud(args->pud_pfn, args->page_prot);
383 pud = pud_mkdevmap(pud);
384 pud = pud_wrprotect(pud);
385 pud = pud_mkclean(pud);
386 set_pud_at(args->mm, vaddr, args->pudp, pud);
387 flush_dcache_page(page);
388 pud = pud_mkwrite(pud);
389 pud = pud_mkdirty(pud);
390 pudp_set_access_flags(args->vma, vaddr, args->pudp, pud, 1);
391 pud = READ_ONCE(*args->pudp);
392 WARN_ON(!(pud_write(pud) && pud_dirty(pud)));
393
394#ifndef __PAGETABLE_PMD_FOLDED
395 pudp_huge_get_and_clear_full(args->vma, vaddr, args->pudp, 1);
396 pud = READ_ONCE(*args->pudp);
397 WARN_ON(!pud_none(pud));
398#endif /* __PAGETABLE_PMD_FOLDED */
399
400 pud = pfn_pud(args->pud_pfn, args->page_prot);
401 pud = pud_mkdevmap(pud);
402 pud = pud_mkyoung(pud);
403 set_pud_at(args->mm, vaddr, args->pudp, pud);
404 flush_dcache_page(page);
405 pudp_test_and_clear_young(args->vma, vaddr, args->pudp);
406 pud = READ_ONCE(*args->pudp);
407 WARN_ON(pud_young(pud));
408
409 pudp_huge_get_and_clear(args->mm, vaddr, args->pudp);
410}
411
412static void __init pud_leaf_tests(struct pgtable_debug_args *args)
413{
414 pud_t pud;
415
416 if (!has_transparent_pud_hugepage())
417 return;
418
419 pr_debug("Validating PUD leaf\n");
420 pud = pfn_pud(args->fixed_pud_pfn, args->page_prot);
421 /*
422 * PUD based THP is a leaf entry.
423 */
424 pud = pud_mkhuge(pud);
425 WARN_ON(!pud_leaf(pud));
426}
427#else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
428static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx) { }
429static void __init pud_advanced_tests(struct pgtable_debug_args *args) { }
430static void __init pud_leaf_tests(struct pgtable_debug_args *args) { }
431#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
432#else /* !CONFIG_TRANSPARENT_HUGEPAGE */
433static void __init pmd_basic_tests(struct pgtable_debug_args *args, int idx) { }
434static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx) { }
435static void __init pmd_advanced_tests(struct pgtable_debug_args *args) { }
436static void __init pud_advanced_tests(struct pgtable_debug_args *args) { }
437static void __init pmd_leaf_tests(struct pgtable_debug_args *args) { }
438static void __init pud_leaf_tests(struct pgtable_debug_args *args) { }
439#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
440
441#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
442static void __init pmd_huge_tests(struct pgtable_debug_args *args)
443{
444 pmd_t pmd;
445
446 if (!arch_vmap_pmd_supported(args->page_prot) ||
447 args->fixed_alignment < PMD_SIZE)
448 return;
449
450 pr_debug("Validating PMD huge\n");
451 /*
452 * X86 defined pmd_set_huge() verifies that the given
453 * PMD is not a populated non-leaf entry.
454 */
455 WRITE_ONCE(*args->pmdp, __pmd(0));
456 WARN_ON(!pmd_set_huge(args->pmdp, __pfn_to_phys(args->fixed_pmd_pfn), args->page_prot));
457 WARN_ON(!pmd_clear_huge(args->pmdp));
458 pmd = READ_ONCE(*args->pmdp);
459 WARN_ON(!pmd_none(pmd));
460}
461
462static void __init pud_huge_tests(struct pgtable_debug_args *args)
463{
464 pud_t pud;
465
466 if (!arch_vmap_pud_supported(args->page_prot) ||
467 args->fixed_alignment < PUD_SIZE)
468 return;
469
470 pr_debug("Validating PUD huge\n");
471 /*
472 * X86 defined pud_set_huge() verifies that the given
473 * PUD is not a populated non-leaf entry.
474 */
475 WRITE_ONCE(*args->pudp, __pud(0));
476 WARN_ON(!pud_set_huge(args->pudp, __pfn_to_phys(args->fixed_pud_pfn), args->page_prot));
477 WARN_ON(!pud_clear_huge(args->pudp));
478 pud = READ_ONCE(*args->pudp);
479 WARN_ON(!pud_none(pud));
480}
481#else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
482static void __init pmd_huge_tests(struct pgtable_debug_args *args) { }
483static void __init pud_huge_tests(struct pgtable_debug_args *args) { }
484#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
485
486static void __init p4d_basic_tests(struct pgtable_debug_args *args)
487{
488 p4d_t p4d;
489
490 pr_debug("Validating P4D basic\n");
491 memset(&p4d, RANDOM_NZVALUE, sizeof(p4d_t));
492 WARN_ON(!p4d_same(p4d, p4d));
493}
494
495static void __init pgd_basic_tests(struct pgtable_debug_args *args)
496{
497 pgd_t pgd;
498
499 pr_debug("Validating PGD basic\n");
500 memset(&pgd, RANDOM_NZVALUE, sizeof(pgd_t));
501 WARN_ON(!pgd_same(pgd, pgd));
502}
503
504#ifndef __PAGETABLE_PUD_FOLDED
505static void __init pud_clear_tests(struct pgtable_debug_args *args)
506{
507 pud_t pud = READ_ONCE(*args->pudp);
508
509 if (mm_pmd_folded(args->mm))
510 return;
511
512 pr_debug("Validating PUD clear\n");
513 pud = __pud(pud_val(pud) | RANDOM_ORVALUE);
514 WRITE_ONCE(*args->pudp, pud);
515 pud_clear(args->pudp);
516 pud = READ_ONCE(*args->pudp);
517 WARN_ON(!pud_none(pud));
518}
519
520static void __init pud_populate_tests(struct pgtable_debug_args *args)
521{
522 pud_t pud;
523
524 if (mm_pmd_folded(args->mm))
525 return;
526
527 pr_debug("Validating PUD populate\n");
528 /*
529 * This entry points to next level page table page.
530 * Hence this must not qualify as pud_bad().
531 */
532 pud_populate(args->mm, args->pudp, args->start_pmdp);
533 pud = READ_ONCE(*args->pudp);
534 WARN_ON(pud_bad(pud));
535}
536#else /* !__PAGETABLE_PUD_FOLDED */
537static void __init pud_clear_tests(struct pgtable_debug_args *args) { }
538static void __init pud_populate_tests(struct pgtable_debug_args *args) { }
539#endif /* PAGETABLE_PUD_FOLDED */
540
541#ifndef __PAGETABLE_P4D_FOLDED
542static void __init p4d_clear_tests(struct pgtable_debug_args *args)
543{
544 p4d_t p4d = READ_ONCE(*args->p4dp);
545
546 if (mm_pud_folded(args->mm))
547 return;
548
549 pr_debug("Validating P4D clear\n");
550 p4d = __p4d(p4d_val(p4d) | RANDOM_ORVALUE);
551 WRITE_ONCE(*args->p4dp, p4d);
552 p4d_clear(args->p4dp);
553 p4d = READ_ONCE(*args->p4dp);
554 WARN_ON(!p4d_none(p4d));
555}
556
557static void __init p4d_populate_tests(struct pgtable_debug_args *args)
558{
559 p4d_t p4d;
560
561 if (mm_pud_folded(args->mm))
562 return;
563
564 pr_debug("Validating P4D populate\n");
565 /*
566 * This entry points to next level page table page.
567 * Hence this must not qualify as p4d_bad().
568 */
569 pud_clear(args->pudp);
570 p4d_clear(args->p4dp);
571 p4d_populate(args->mm, args->p4dp, args->start_pudp);
572 p4d = READ_ONCE(*args->p4dp);
573 WARN_ON(p4d_bad(p4d));
574}
575
576static void __init pgd_clear_tests(struct pgtable_debug_args *args)
577{
578 pgd_t pgd = READ_ONCE(*(args->pgdp));
579
580 if (mm_p4d_folded(args->mm))
581 return;
582
583 pr_debug("Validating PGD clear\n");
584 pgd = __pgd(pgd_val(pgd) | RANDOM_ORVALUE);
585 WRITE_ONCE(*args->pgdp, pgd);
586 pgd_clear(args->pgdp);
587 pgd = READ_ONCE(*args->pgdp);
588 WARN_ON(!pgd_none(pgd));
589}
590
591static void __init pgd_populate_tests(struct pgtable_debug_args *args)
592{
593 pgd_t pgd;
594
595 if (mm_p4d_folded(args->mm))
596 return;
597
598 pr_debug("Validating PGD populate\n");
599 /*
600 * This entry points to next level page table page.
601 * Hence this must not qualify as pgd_bad().
602 */
603 p4d_clear(args->p4dp);
604 pgd_clear(args->pgdp);
605 pgd_populate(args->mm, args->pgdp, args->start_p4dp);
606 pgd = READ_ONCE(*args->pgdp);
607 WARN_ON(pgd_bad(pgd));
608}
609#else /* !__PAGETABLE_P4D_FOLDED */
610static void __init p4d_clear_tests(struct pgtable_debug_args *args) { }
611static void __init pgd_clear_tests(struct pgtable_debug_args *args) { }
612static void __init p4d_populate_tests(struct pgtable_debug_args *args) { }
613static void __init pgd_populate_tests(struct pgtable_debug_args *args) { }
614#endif /* PAGETABLE_P4D_FOLDED */
615
616static void __init pte_clear_tests(struct pgtable_debug_args *args)
617{
618 struct page *page;
619 pte_t pte = pfn_pte(args->pte_pfn, args->page_prot);
620
621 page = (args->pte_pfn != ULONG_MAX) ? pfn_to_page(args->pte_pfn) : NULL;
622 if (!page)
623 return;
624
625 /*
626 * flush_dcache_page() is called after set_pte_at() to clear
627 * PG_arch_1 for the page on ARM64. The page flag isn't cleared
628 * when it's released and page allocation check will fail when
629 * the page is allocated again. For architectures other than ARM64,
630 * the unexpected overhead of cache flushing is acceptable.
631 */
632 pr_debug("Validating PTE clear\n");
633 if (WARN_ON(!args->ptep))
634 return;
635
636#ifndef CONFIG_RISCV
637 pte = __pte(pte_val(pte) | RANDOM_ORVALUE);
638#endif
639 set_pte_at(args->mm, args->vaddr, args->ptep, pte);
640 flush_dcache_page(page);
641 barrier();
642 ptep_clear(args->mm, args->vaddr, args->ptep);
643 pte = ptep_get(args->ptep);
644 WARN_ON(!pte_none(pte));
645}
646
647static void __init pmd_clear_tests(struct pgtable_debug_args *args)
648{
649 pmd_t pmd = READ_ONCE(*args->pmdp);
650
651 pr_debug("Validating PMD clear\n");
652 pmd = __pmd(pmd_val(pmd) | RANDOM_ORVALUE);
653 WRITE_ONCE(*args->pmdp, pmd);
654 pmd_clear(args->pmdp);
655 pmd = READ_ONCE(*args->pmdp);
656 WARN_ON(!pmd_none(pmd));
657}
658
659static void __init pmd_populate_tests(struct pgtable_debug_args *args)
660{
661 pmd_t pmd;
662
663 pr_debug("Validating PMD populate\n");
664 /*
665 * This entry points to next level page table page.
666 * Hence this must not qualify as pmd_bad().
667 */
668 pmd_populate(args->mm, args->pmdp, args->start_ptep);
669 pmd = READ_ONCE(*args->pmdp);
670 WARN_ON(pmd_bad(pmd));
671}
672
673static void __init pte_special_tests(struct pgtable_debug_args *args)
674{
675 pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot);
676
677 if (!IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL))
678 return;
679
680 pr_debug("Validating PTE special\n");
681 WARN_ON(!pte_special(pte_mkspecial(pte)));
682}
683
684static void __init pte_protnone_tests(struct pgtable_debug_args *args)
685{
686 pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot_none);
687
688 if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
689 return;
690
691 pr_debug("Validating PTE protnone\n");
692 WARN_ON(!pte_protnone(pte));
693 WARN_ON(!pte_present(pte));
694}
695
696#ifdef CONFIG_TRANSPARENT_HUGEPAGE
697static void __init pmd_protnone_tests(struct pgtable_debug_args *args)
698{
699 pmd_t pmd;
700
701 if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
702 return;
703
704 if (!has_transparent_hugepage())
705 return;
706
707 pr_debug("Validating PMD protnone\n");
708 pmd = pmd_mkhuge(pfn_pmd(args->fixed_pmd_pfn, args->page_prot_none));
709 WARN_ON(!pmd_protnone(pmd));
710 WARN_ON(!pmd_present(pmd));
711}
712#else /* !CONFIG_TRANSPARENT_HUGEPAGE */
713static void __init pmd_protnone_tests(struct pgtable_debug_args *args) { }
714#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
715
716#ifdef CONFIG_ARCH_HAS_PTE_DEVMAP
717static void __init pte_devmap_tests(struct pgtable_debug_args *args)
718{
719 pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot);
720
721 pr_debug("Validating PTE devmap\n");
722 WARN_ON(!pte_devmap(pte_mkdevmap(pte)));
723}
724
725#ifdef CONFIG_TRANSPARENT_HUGEPAGE
726static void __init pmd_devmap_tests(struct pgtable_debug_args *args)
727{
728 pmd_t pmd;
729
730 if (!has_transparent_hugepage())
731 return;
732
733 pr_debug("Validating PMD devmap\n");
734 pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot);
735 WARN_ON(!pmd_devmap(pmd_mkdevmap(pmd)));
736}
737
738#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
739static void __init pud_devmap_tests(struct pgtable_debug_args *args)
740{
741 pud_t pud;
742
743 if (!has_transparent_pud_hugepage())
744 return;
745
746 pr_debug("Validating PUD devmap\n");
747 pud = pfn_pud(args->fixed_pud_pfn, args->page_prot);
748 WARN_ON(!pud_devmap(pud_mkdevmap(pud)));
749}
750#else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
751static void __init pud_devmap_tests(struct pgtable_debug_args *args) { }
752#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
753#else /* CONFIG_TRANSPARENT_HUGEPAGE */
754static void __init pmd_devmap_tests(struct pgtable_debug_args *args) { }
755static void __init pud_devmap_tests(struct pgtable_debug_args *args) { }
756#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
757#else
758static void __init pte_devmap_tests(struct pgtable_debug_args *args) { }
759static void __init pmd_devmap_tests(struct pgtable_debug_args *args) { }
760static void __init pud_devmap_tests(struct pgtable_debug_args *args) { }
761#endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */
762
763static void __init pte_soft_dirty_tests(struct pgtable_debug_args *args)
764{
765 pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot);
766
767 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
768 return;
769
770 pr_debug("Validating PTE soft dirty\n");
771 WARN_ON(!pte_soft_dirty(pte_mksoft_dirty(pte)));
772 WARN_ON(pte_soft_dirty(pte_clear_soft_dirty(pte)));
773}
774
775static void __init pte_swap_soft_dirty_tests(struct pgtable_debug_args *args)
776{
777 pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot);
778
779 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
780 return;
781
782 pr_debug("Validating PTE swap soft dirty\n");
783 WARN_ON(!pte_swp_soft_dirty(pte_swp_mksoft_dirty(pte)));
784 WARN_ON(pte_swp_soft_dirty(pte_swp_clear_soft_dirty(pte)));
785}
786
787#ifdef CONFIG_TRANSPARENT_HUGEPAGE
788static void __init pmd_soft_dirty_tests(struct pgtable_debug_args *args)
789{
790 pmd_t pmd;
791
792 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
793 return;
794
795 if (!has_transparent_hugepage())
796 return;
797
798 pr_debug("Validating PMD soft dirty\n");
799 pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot);
800 WARN_ON(!pmd_soft_dirty(pmd_mksoft_dirty(pmd)));
801 WARN_ON(pmd_soft_dirty(pmd_clear_soft_dirty(pmd)));
802}
803
804static void __init pmd_swap_soft_dirty_tests(struct pgtable_debug_args *args)
805{
806 pmd_t pmd;
807
808 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY) ||
809 !IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION))
810 return;
811
812 if (!has_transparent_hugepage())
813 return;
814
815 pr_debug("Validating PMD swap soft dirty\n");
816 pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot);
817 WARN_ON(!pmd_swp_soft_dirty(pmd_swp_mksoft_dirty(pmd)));
818 WARN_ON(pmd_swp_soft_dirty(pmd_swp_clear_soft_dirty(pmd)));
819}
820#else /* !CONFIG_TRANSPARENT_HUGEPAGE */
821static void __init pmd_soft_dirty_tests(struct pgtable_debug_args *args) { }
822static void __init pmd_swap_soft_dirty_tests(struct pgtable_debug_args *args) { }
823#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
824
825static void __init pte_swap_exclusive_tests(struct pgtable_debug_args *args)
826{
827 unsigned long max_swap_offset;
828 swp_entry_t entry, entry2;
829 pte_t pte;
830
831 pr_debug("Validating PTE swap exclusive\n");
832
833 /* See generic_max_swapfile_size(): probe the maximum offset */
834 max_swap_offset = swp_offset(pte_to_swp_entry(swp_entry_to_pte(swp_entry(0, ~0UL))));
835
836 /* Create a swp entry with all possible bits set */
837 entry = swp_entry((1 << MAX_SWAPFILES_SHIFT) - 1, max_swap_offset);
838
839 pte = swp_entry_to_pte(entry);
840 WARN_ON(pte_swp_exclusive(pte));
841 WARN_ON(!is_swap_pte(pte));
842 entry2 = pte_to_swp_entry(pte);
843 WARN_ON(memcmp(&entry, &entry2, sizeof(entry)));
844
845 pte = pte_swp_mkexclusive(pte);
846 WARN_ON(!pte_swp_exclusive(pte));
847 WARN_ON(!is_swap_pte(pte));
848 WARN_ON(pte_swp_soft_dirty(pte));
849 entry2 = pte_to_swp_entry(pte);
850 WARN_ON(memcmp(&entry, &entry2, sizeof(entry)));
851
852 pte = pte_swp_clear_exclusive(pte);
853 WARN_ON(pte_swp_exclusive(pte));
854 WARN_ON(!is_swap_pte(pte));
855 entry2 = pte_to_swp_entry(pte);
856 WARN_ON(memcmp(&entry, &entry2, sizeof(entry)));
857}
858
859static void __init pte_swap_tests(struct pgtable_debug_args *args)
860{
861 swp_entry_t swp;
862 pte_t pte;
863
864 pr_debug("Validating PTE swap\n");
865 pte = pfn_pte(args->fixed_pte_pfn, args->page_prot);
866 swp = __pte_to_swp_entry(pte);
867 pte = __swp_entry_to_pte(swp);
868 WARN_ON(args->fixed_pte_pfn != pte_pfn(pte));
869}
870
871#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
872static void __init pmd_swap_tests(struct pgtable_debug_args *args)
873{
874 swp_entry_t swp;
875 pmd_t pmd;
876
877 if (!has_transparent_hugepage())
878 return;
879
880 pr_debug("Validating PMD swap\n");
881 pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot);
882 swp = __pmd_to_swp_entry(pmd);
883 pmd = __swp_entry_to_pmd(swp);
884 WARN_ON(args->fixed_pmd_pfn != pmd_pfn(pmd));
885}
886#else /* !CONFIG_ARCH_ENABLE_THP_MIGRATION */
887static void __init pmd_swap_tests(struct pgtable_debug_args *args) { }
888#endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
889
890static void __init swap_migration_tests(struct pgtable_debug_args *args)
891{
892 struct page *page;
893 swp_entry_t swp;
894
895 if (!IS_ENABLED(CONFIG_MIGRATION))
896 return;
897
898 /*
899 * swap_migration_tests() requires a dedicated page as it needs to
900 * be locked before creating a migration entry from it. Locking the
901 * page that actually maps kernel text ('start_kernel') can be real
902 * problematic. Lets use the allocated page explicitly for this
903 * purpose.
904 */
905 page = (args->pte_pfn != ULONG_MAX) ? pfn_to_page(args->pte_pfn) : NULL;
906 if (!page)
907 return;
908
909 pr_debug("Validating swap migration\n");
910
911 /*
912 * make_[readable|writable]_migration_entry() expects given page to
913 * be locked, otherwise it stumbles upon a BUG_ON().
914 */
915 __SetPageLocked(page);
916 swp = make_writable_migration_entry(page_to_pfn(page));
917 WARN_ON(!is_migration_entry(swp));
918 WARN_ON(!is_writable_migration_entry(swp));
919
920 swp = make_readable_migration_entry(swp_offset(swp));
921 WARN_ON(!is_migration_entry(swp));
922 WARN_ON(is_writable_migration_entry(swp));
923
924 swp = make_readable_migration_entry(page_to_pfn(page));
925 WARN_ON(!is_migration_entry(swp));
926 WARN_ON(is_writable_migration_entry(swp));
927 __ClearPageLocked(page);
928}
929
930#ifdef CONFIG_HUGETLB_PAGE
931static void __init hugetlb_basic_tests(struct pgtable_debug_args *args)
932{
933 struct page *page;
934 pte_t pte;
935
936 pr_debug("Validating HugeTLB basic\n");
937 /*
938 * Accessing the page associated with the pfn is safe here,
939 * as it was previously derived from a real kernel symbol.
940 */
941 page = pfn_to_page(args->fixed_pmd_pfn);
942 pte = mk_huge_pte(page, args->page_prot);
943
944 WARN_ON(!huge_pte_dirty(huge_pte_mkdirty(pte)));
945 WARN_ON(!huge_pte_write(huge_pte_mkwrite(huge_pte_wrprotect(pte))));
946 WARN_ON(huge_pte_write(huge_pte_wrprotect(huge_pte_mkwrite(pte))));
947
948#ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB
949 pte = pfn_pte(args->fixed_pmd_pfn, args->page_prot);
950
951 WARN_ON(!pte_huge(arch_make_huge_pte(pte, PMD_SHIFT, VM_ACCESS_FLAGS)));
952#endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */
953}
954#else /* !CONFIG_HUGETLB_PAGE */
955static void __init hugetlb_basic_tests(struct pgtable_debug_args *args) { }
956#endif /* CONFIG_HUGETLB_PAGE */
957
958#ifdef CONFIG_TRANSPARENT_HUGEPAGE
959static void __init pmd_thp_tests(struct pgtable_debug_args *args)
960{
961 pmd_t pmd;
962
963 if (!has_transparent_hugepage())
964 return;
965
966 pr_debug("Validating PMD based THP\n");
967 /*
968 * pmd_trans_huge() and pmd_present() must return positive after
969 * MMU invalidation with pmd_mkinvalid(). This behavior is an
970 * optimization for transparent huge page. pmd_trans_huge() must
971 * be true if pmd_page() returns a valid THP to avoid taking the
972 * pmd_lock when others walk over non transhuge pmds (i.e. there
973 * are no THP allocated). Especially when splitting a THP and
974 * removing the present bit from the pmd, pmd_trans_huge() still
975 * needs to return true. pmd_present() should be true whenever
976 * pmd_trans_huge() returns true.
977 */
978 pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot);
979 WARN_ON(!pmd_trans_huge(pmd_mkhuge(pmd)));
980
981#ifndef __HAVE_ARCH_PMDP_INVALIDATE
982 WARN_ON(!pmd_trans_huge(pmd_mkinvalid(pmd_mkhuge(pmd))));
983 WARN_ON(!pmd_present(pmd_mkinvalid(pmd_mkhuge(pmd))));
984#endif /* __HAVE_ARCH_PMDP_INVALIDATE */
985}
986
987#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
988static void __init pud_thp_tests(struct pgtable_debug_args *args)
989{
990 pud_t pud;
991
992 if (!has_transparent_pud_hugepage())
993 return;
994
995 pr_debug("Validating PUD based THP\n");
996 pud = pfn_pud(args->fixed_pud_pfn, args->page_prot);
997 WARN_ON(!pud_trans_huge(pud_mkhuge(pud)));
998
999 /*
1000 * pud_mkinvalid() has been dropped for now. Enable back
1001 * these tests when it comes back with a modified pud_present().
1002 *
1003 * WARN_ON(!pud_trans_huge(pud_mkinvalid(pud_mkhuge(pud))));
1004 * WARN_ON(!pud_present(pud_mkinvalid(pud_mkhuge(pud))));
1005 */
1006}
1007#else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
1008static void __init pud_thp_tests(struct pgtable_debug_args *args) { }
1009#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
1010#else /* !CONFIG_TRANSPARENT_HUGEPAGE */
1011static void __init pmd_thp_tests(struct pgtable_debug_args *args) { }
1012static void __init pud_thp_tests(struct pgtable_debug_args *args) { }
1013#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1014
1015static unsigned long __init get_random_vaddr(void)
1016{
1017 unsigned long random_vaddr, random_pages, total_user_pages;
1018
1019 total_user_pages = (TASK_SIZE - FIRST_USER_ADDRESS) / PAGE_SIZE;
1020
1021 random_pages = get_random_long() % total_user_pages;
1022 random_vaddr = FIRST_USER_ADDRESS + random_pages * PAGE_SIZE;
1023
1024 return random_vaddr;
1025}
1026
1027static void __init destroy_args(struct pgtable_debug_args *args)
1028{
1029 struct page *page = NULL;
1030
1031 /* Free (huge) page */
1032 if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
1033 has_transparent_pud_hugepage() &&
1034 args->pud_pfn != ULONG_MAX) {
1035 if (args->is_contiguous_page) {
1036 free_contig_range(args->pud_pfn,
1037 (1 << (HPAGE_PUD_SHIFT - PAGE_SHIFT)));
1038 } else {
1039 page = pfn_to_page(args->pud_pfn);
1040 __free_pages(page, HPAGE_PUD_SHIFT - PAGE_SHIFT);
1041 }
1042
1043 args->pud_pfn = ULONG_MAX;
1044 args->pmd_pfn = ULONG_MAX;
1045 args->pte_pfn = ULONG_MAX;
1046 }
1047
1048 if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
1049 has_transparent_hugepage() &&
1050 args->pmd_pfn != ULONG_MAX) {
1051 if (args->is_contiguous_page) {
1052 free_contig_range(args->pmd_pfn, (1 << HPAGE_PMD_ORDER));
1053 } else {
1054 page = pfn_to_page(args->pmd_pfn);
1055 __free_pages(page, HPAGE_PMD_ORDER);
1056 }
1057
1058 args->pmd_pfn = ULONG_MAX;
1059 args->pte_pfn = ULONG_MAX;
1060 }
1061
1062 if (args->pte_pfn != ULONG_MAX) {
1063 page = pfn_to_page(args->pte_pfn);
1064 __free_page(page);
1065
1066 args->pte_pfn = ULONG_MAX;
1067 }
1068
1069 /* Free page table entries */
1070 if (args->start_ptep) {
1071 pte_free(args->mm, args->start_ptep);
1072 mm_dec_nr_ptes(args->mm);
1073 }
1074
1075 if (args->start_pmdp) {
1076 pmd_free(args->mm, args->start_pmdp);
1077 mm_dec_nr_pmds(args->mm);
1078 }
1079
1080 if (args->start_pudp) {
1081 pud_free(args->mm, args->start_pudp);
1082 mm_dec_nr_puds(args->mm);
1083 }
1084
1085 if (args->start_p4dp)
1086 p4d_free(args->mm, args->start_p4dp);
1087
1088 /* Free vma and mm struct */
1089 if (args->vma)
1090 vm_area_free(args->vma);
1091
1092 if (args->mm)
1093 mmdrop(args->mm);
1094}
1095
1096static struct page * __init
1097debug_vm_pgtable_alloc_huge_page(struct pgtable_debug_args *args, int order)
1098{
1099 struct page *page = NULL;
1100
1101#ifdef CONFIG_CONTIG_ALLOC
1102 if (order > MAX_PAGE_ORDER) {
1103 page = alloc_contig_pages((1 << order), GFP_KERNEL,
1104 first_online_node, NULL);
1105 if (page) {
1106 args->is_contiguous_page = true;
1107 return page;
1108 }
1109 }
1110#endif
1111
1112 if (order <= MAX_PAGE_ORDER)
1113 page = alloc_pages(GFP_KERNEL, order);
1114
1115 return page;
1116}
1117
1118/*
1119 * Check if a physical memory range described by <pstart, pend> contains
1120 * an area that is of size psize, and aligned to psize.
1121 *
1122 * Don't use address 0, an all-zeroes physical address might mask bugs, and
1123 * it's not used on x86.
1124 */
1125static void __init phys_align_check(phys_addr_t pstart,
1126 phys_addr_t pend, unsigned long psize,
1127 phys_addr_t *physp, unsigned long *alignp)
1128{
1129 phys_addr_t aligned_start, aligned_end;
1130
1131 if (pstart == 0)
1132 pstart = PAGE_SIZE;
1133
1134 aligned_start = ALIGN(pstart, psize);
1135 aligned_end = aligned_start + psize;
1136
1137 if (aligned_end > aligned_start && aligned_end <= pend) {
1138 *alignp = psize;
1139 *physp = aligned_start;
1140 }
1141}
1142
1143static void __init init_fixed_pfns(struct pgtable_debug_args *args)
1144{
1145 u64 idx;
1146 phys_addr_t phys, pstart, pend;
1147
1148 /*
1149 * Initialize the fixed pfns. To do this, try to find a
1150 * valid physical range, preferably aligned to PUD_SIZE,
1151 * but settling for aligned to PMD_SIZE as a fallback. If
1152 * neither of those is found, use the physical address of
1153 * the start_kernel symbol.
1154 *
1155 * The memory doesn't need to be allocated, it just needs to exist
1156 * as usable memory. It won't be touched.
1157 *
1158 * The alignment is recorded, and can be checked to see if we
1159 * can run the tests that require an actual valid physical
1160 * address range on some architectures ({pmd,pud}_huge_test
1161 * on x86).
1162 */
1163
1164 phys = __pa_symbol(&start_kernel);
1165 args->fixed_alignment = PAGE_SIZE;
1166
1167 for_each_mem_range(idx, &pstart, &pend) {
1168 /* First check for a PUD-aligned area */
1169 phys_align_check(pstart, pend, PUD_SIZE, &phys,
1170 &args->fixed_alignment);
1171
1172 /* If a PUD-aligned area is found, we're done */
1173 if (args->fixed_alignment == PUD_SIZE)
1174 break;
1175
1176 /*
1177 * If no PMD-aligned area found yet, check for one,
1178 * but continue the loop to look for a PUD-aligned area.
1179 */
1180 if (args->fixed_alignment < PMD_SIZE)
1181 phys_align_check(pstart, pend, PMD_SIZE, &phys,
1182 &args->fixed_alignment);
1183 }
1184
1185 args->fixed_pgd_pfn = __phys_to_pfn(phys & PGDIR_MASK);
1186 args->fixed_p4d_pfn = __phys_to_pfn(phys & P4D_MASK);
1187 args->fixed_pud_pfn = __phys_to_pfn(phys & PUD_MASK);
1188 args->fixed_pmd_pfn = __phys_to_pfn(phys & PMD_MASK);
1189 args->fixed_pte_pfn = __phys_to_pfn(phys & PAGE_MASK);
1190 WARN_ON(!pfn_valid(args->fixed_pte_pfn));
1191}
1192
1193
1194static int __init init_args(struct pgtable_debug_args *args)
1195{
1196 struct page *page = NULL;
1197 int ret = 0;
1198
1199 /*
1200 * Initialize the debugging data.
1201 *
1202 * vm_get_page_prot(VM_NONE) or vm_get_page_prot(VM_SHARED|VM_NONE)
1203 * will help create page table entries with PROT_NONE permission as
1204 * required for pxx_protnone_tests().
1205 */
1206 memset(args, 0, sizeof(*args));
1207 args->vaddr = get_random_vaddr();
1208 args->page_prot = vm_get_page_prot(VM_ACCESS_FLAGS);
1209 args->page_prot_none = vm_get_page_prot(VM_NONE);
1210 args->is_contiguous_page = false;
1211 args->pud_pfn = ULONG_MAX;
1212 args->pmd_pfn = ULONG_MAX;
1213 args->pte_pfn = ULONG_MAX;
1214 args->fixed_pgd_pfn = ULONG_MAX;
1215 args->fixed_p4d_pfn = ULONG_MAX;
1216 args->fixed_pud_pfn = ULONG_MAX;
1217 args->fixed_pmd_pfn = ULONG_MAX;
1218 args->fixed_pte_pfn = ULONG_MAX;
1219
1220 /* Allocate mm and vma */
1221 args->mm = mm_alloc();
1222 if (!args->mm) {
1223 pr_err("Failed to allocate mm struct\n");
1224 ret = -ENOMEM;
1225 goto error;
1226 }
1227
1228 args->vma = vm_area_alloc(args->mm);
1229 if (!args->vma) {
1230 pr_err("Failed to allocate vma\n");
1231 ret = -ENOMEM;
1232 goto error;
1233 }
1234
1235 /*
1236 * Allocate page table entries. They will be modified in the tests.
1237 * Lets save the page table entries so that they can be released
1238 * when the tests are completed.
1239 */
1240 args->pgdp = pgd_offset(args->mm, args->vaddr);
1241 args->p4dp = p4d_alloc(args->mm, args->pgdp, args->vaddr);
1242 if (!args->p4dp) {
1243 pr_err("Failed to allocate p4d entries\n");
1244 ret = -ENOMEM;
1245 goto error;
1246 }
1247 args->start_p4dp = p4d_offset(args->pgdp, 0UL);
1248 WARN_ON(!args->start_p4dp);
1249
1250 args->pudp = pud_alloc(args->mm, args->p4dp, args->vaddr);
1251 if (!args->pudp) {
1252 pr_err("Failed to allocate pud entries\n");
1253 ret = -ENOMEM;
1254 goto error;
1255 }
1256 args->start_pudp = pud_offset(args->p4dp, 0UL);
1257 WARN_ON(!args->start_pudp);
1258
1259 args->pmdp = pmd_alloc(args->mm, args->pudp, args->vaddr);
1260 if (!args->pmdp) {
1261 pr_err("Failed to allocate pmd entries\n");
1262 ret = -ENOMEM;
1263 goto error;
1264 }
1265 args->start_pmdp = pmd_offset(args->pudp, 0UL);
1266 WARN_ON(!args->start_pmdp);
1267
1268 if (pte_alloc(args->mm, args->pmdp)) {
1269 pr_err("Failed to allocate pte entries\n");
1270 ret = -ENOMEM;
1271 goto error;
1272 }
1273 args->start_ptep = pmd_pgtable(READ_ONCE(*args->pmdp));
1274 WARN_ON(!args->start_ptep);
1275
1276 init_fixed_pfns(args);
1277
1278 /*
1279 * Allocate (huge) pages because some of the tests need to access
1280 * the data in the pages. The corresponding tests will be skipped
1281 * if we fail to allocate (huge) pages.
1282 */
1283 if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
1284 has_transparent_pud_hugepage()) {
1285 page = debug_vm_pgtable_alloc_huge_page(args,
1286 HPAGE_PUD_SHIFT - PAGE_SHIFT);
1287 if (page) {
1288 args->pud_pfn = page_to_pfn(page);
1289 args->pmd_pfn = args->pud_pfn;
1290 args->pte_pfn = args->pud_pfn;
1291 return 0;
1292 }
1293 }
1294
1295 if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
1296 has_transparent_hugepage()) {
1297 page = debug_vm_pgtable_alloc_huge_page(args, HPAGE_PMD_ORDER);
1298 if (page) {
1299 args->pmd_pfn = page_to_pfn(page);
1300 args->pte_pfn = args->pmd_pfn;
1301 return 0;
1302 }
1303 }
1304
1305 page = alloc_page(GFP_KERNEL);
1306 if (page)
1307 args->pte_pfn = page_to_pfn(page);
1308
1309 return 0;
1310
1311error:
1312 destroy_args(args);
1313 return ret;
1314}
1315
1316static int __init debug_vm_pgtable(void)
1317{
1318 struct pgtable_debug_args args;
1319 spinlock_t *ptl = NULL;
1320 int idx, ret;
1321
1322 pr_info("Validating architecture page table helpers\n");
1323 ret = init_args(&args);
1324 if (ret)
1325 return ret;
1326
1327 /*
1328 * Iterate over each possible vm_flags to make sure that all
1329 * the basic page table transformation validations just hold
1330 * true irrespective of the starting protection value for a
1331 * given page table entry.
1332 *
1333 * Protection based vm_flags combinations are always linear
1334 * and increasing i.e starting from VM_NONE and going up to
1335 * (VM_SHARED | READ | WRITE | EXEC).
1336 */
1337#define VM_FLAGS_START (VM_NONE)
1338#define VM_FLAGS_END (VM_SHARED | VM_EXEC | VM_WRITE | VM_READ)
1339
1340 for (idx = VM_FLAGS_START; idx <= VM_FLAGS_END; idx++) {
1341 pte_basic_tests(&args, idx);
1342 pmd_basic_tests(&args, idx);
1343 pud_basic_tests(&args, idx);
1344 }
1345
1346 /*
1347 * Both P4D and PGD level tests are very basic which do not
1348 * involve creating page table entries from the protection
1349 * value and the given pfn. Hence just keep them out from
1350 * the above iteration for now to save some test execution
1351 * time.
1352 */
1353 p4d_basic_tests(&args);
1354 pgd_basic_tests(&args);
1355
1356 pmd_leaf_tests(&args);
1357 pud_leaf_tests(&args);
1358
1359 pte_special_tests(&args);
1360 pte_protnone_tests(&args);
1361 pmd_protnone_tests(&args);
1362
1363 pte_devmap_tests(&args);
1364 pmd_devmap_tests(&args);
1365 pud_devmap_tests(&args);
1366
1367 pte_soft_dirty_tests(&args);
1368 pmd_soft_dirty_tests(&args);
1369 pte_swap_soft_dirty_tests(&args);
1370 pmd_swap_soft_dirty_tests(&args);
1371
1372 pte_swap_exclusive_tests(&args);
1373
1374 pte_swap_tests(&args);
1375 pmd_swap_tests(&args);
1376
1377 swap_migration_tests(&args);
1378
1379 pmd_thp_tests(&args);
1380 pud_thp_tests(&args);
1381
1382 hugetlb_basic_tests(&args);
1383
1384 /*
1385 * Page table modifying tests. They need to hold
1386 * proper page table lock.
1387 */
1388
1389 args.ptep = pte_offset_map_lock(args.mm, args.pmdp, args.vaddr, &ptl);
1390 pte_clear_tests(&args);
1391 pte_advanced_tests(&args);
1392 if (args.ptep)
1393 pte_unmap_unlock(args.ptep, ptl);
1394
1395 ptl = pmd_lock(args.mm, args.pmdp);
1396 pmd_clear_tests(&args);
1397 pmd_advanced_tests(&args);
1398 pmd_huge_tests(&args);
1399 pmd_populate_tests(&args);
1400 spin_unlock(ptl);
1401
1402 ptl = pud_lock(args.mm, args.pudp);
1403 pud_clear_tests(&args);
1404 pud_advanced_tests(&args);
1405 pud_huge_tests(&args);
1406 pud_populate_tests(&args);
1407 spin_unlock(ptl);
1408
1409 spin_lock(&(args.mm->page_table_lock));
1410 p4d_clear_tests(&args);
1411 pgd_clear_tests(&args);
1412 p4d_populate_tests(&args);
1413 pgd_populate_tests(&args);
1414 spin_unlock(&(args.mm->page_table_lock));
1415
1416 destroy_args(&args);
1417 return 0;
1418}
1419late_initcall(debug_vm_pgtable);