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#include <linux/vmalloc.h>
34
35#include <asm/cacheflush.h>
36#include <asm/pgalloc.h>
37#include <asm/tlbflush.h>
38
39/*
40 * Please refer Documentation/mm/arch_pgtable_helpers.rst for the semantics
41 * expectations that are being validated here. All future changes in here
42 * or the documentation need to be in sync.
43 */
44#define RANDOM_NZVALUE GENMASK(7, 0)
45
46struct pgtable_debug_args {
47 struct mm_struct *mm;
48 struct vm_area_struct *vma;
49
50 pgd_t *pgdp;
51 p4d_t *p4dp;
52 pud_t *pudp;
53 pmd_t *pmdp;
54 pte_t *ptep;
55
56 p4d_t *start_p4dp;
57 pud_t *start_pudp;
58 pmd_t *start_pmdp;
59 pgtable_t start_ptep;
60
61 unsigned long vaddr;
62 pgprot_t page_prot;
63 pgprot_t page_prot_none;
64
65 bool is_contiguous_page;
66 unsigned long pud_pfn;
67 unsigned long pmd_pfn;
68 unsigned long pte_pfn;
69
70 unsigned long fixed_alignment;
71 unsigned long fixed_pgd_pfn;
72 unsigned long fixed_p4d_pfn;
73 unsigned long fixed_pud_pfn;
74 unsigned long fixed_pmd_pfn;
75 unsigned long fixed_pte_pfn;
76};
77
78static void __init pte_basic_tests(struct pgtable_debug_args *args, int idx)
79{
80 pgprot_t prot = vm_get_page_prot(vm_flags: idx);
81 pte_t pte = pfn_pte(page_nr: args->fixed_pte_pfn, pgprot: prot);
82 unsigned long val = idx, *ptr = &val;
83
84 pr_debug("Validating PTE basic (%pGv)\n", ptr);
85
86 /*
87 * This test needs to be executed after the given page table entry
88 * is created with pfn_pte() to make sure that vm_get_page_prot(idx)
89 * does not have the dirty bit enabled from the beginning. This is
90 * important for platforms like arm64 where (!PTE_RDONLY) indicate
91 * dirty bit being set.
92 */
93 WARN_ON(pte_dirty(pte_wrprotect(pte)));
94
95 WARN_ON(!pte_same(pte, pte));
96 WARN_ON(!pte_young(pte_mkyoung(pte_mkold(pte))));
97 WARN_ON(!pte_dirty(pte_mkdirty(pte_mkclean(pte))));
98 WARN_ON(!pte_write(pte_mkwrite(pte_wrprotect(pte), args->vma)));
99 WARN_ON(pte_young(pte_mkold(pte_mkyoung(pte))));
100 WARN_ON(pte_dirty(pte_mkclean(pte_mkdirty(pte))));
101 WARN_ON(pte_write(pte_wrprotect(pte_mkwrite(pte, args->vma))));
102 WARN_ON(pte_dirty(pte_wrprotect(pte_mkclean(pte))));
103 WARN_ON(!pte_dirty(pte_wrprotect(pte_mkdirty(pte))));
104}
105
106static void __init pte_advanced_tests(struct pgtable_debug_args *args)
107{
108 struct page *page;
109 pte_t pte;
110
111 /*
112 * Architectures optimize set_pte_at by avoiding TLB flush.
113 * This requires set_pte_at to be not used to update an
114 * existing pte entry. Clear pte before we do set_pte_at
115 *
116 * flush_dcache_page() is called after set_pte_at() to clear
117 * PG_arch_1 for the page on ARM64. The page flag isn't cleared
118 * when it's released and page allocation check will fail when
119 * the page is allocated again. For architectures other than ARM64,
120 * the unexpected overhead of cache flushing is acceptable.
121 */
122 page = (args->pte_pfn != ULONG_MAX) ? pfn_to_page(args->pte_pfn) : NULL;
123 if (!page)
124 return;
125
126 pr_debug("Validating PTE advanced\n");
127 if (WARN_ON(!args->ptep))
128 return;
129
130 pte = pfn_pte(page_nr: args->pte_pfn, pgprot: args->page_prot);
131 set_pte_at(args->mm, args->vaddr, args->ptep, pte);
132 flush_dcache_page(page);
133 ptep_set_wrprotect(mm: args->mm, addr: args->vaddr, ptep: args->ptep);
134 pte = ptep_get(ptep: args->ptep);
135 WARN_ON(pte_write(pte));
136 ptep_get_and_clear(mm: args->mm, addr: args->vaddr, ptep: args->ptep);
137 pte = ptep_get(ptep: args->ptep);
138 WARN_ON(!pte_none(pte));
139
140 pte = pfn_pte(page_nr: args->pte_pfn, pgprot: args->page_prot);
141 pte = pte_wrprotect(pte);
142 pte = pte_mkclean(pte);
143 set_pte_at(args->mm, args->vaddr, args->ptep, pte);
144 flush_dcache_page(page);
145 pte = pte_mkwrite(pte, vma: args->vma);
146 pte = pte_mkdirty(pte);
147 ptep_set_access_flags(vma: args->vma, address: args->vaddr, ptep: args->ptep, entry: pte, dirty: 1);
148 pte = ptep_get(ptep: args->ptep);
149 WARN_ON(!(pte_write(pte) && pte_dirty(pte)));
150 ptep_get_and_clear_full(mm: args->mm, addr: args->vaddr, ptep: args->ptep, full: 1);
151 pte = ptep_get(ptep: args->ptep);
152 WARN_ON(!pte_none(pte));
153
154 pte = pfn_pte(page_nr: args->pte_pfn, pgprot: args->page_prot);
155 pte = pte_mkyoung(pte);
156 set_pte_at(args->mm, args->vaddr, args->ptep, pte);
157 flush_dcache_page(page);
158 ptep_test_and_clear_young(vma: args->vma, addr: args->vaddr, ptep: args->ptep);
159 pte = ptep_get(ptep: args->ptep);
160 WARN_ON(pte_young(pte));
161
162 ptep_get_and_clear_full(mm: args->mm, addr: args->vaddr, ptep: args->ptep, full: 1);
163}
164
165#ifdef CONFIG_TRANSPARENT_HUGEPAGE
166static void __init pmd_basic_tests(struct pgtable_debug_args *args, int idx)
167{
168 pgprot_t prot = vm_get_page_prot(vm_flags: idx);
169 unsigned long val = idx, *ptr = &val;
170 pmd_t pmd;
171
172 if (!has_transparent_hugepage())
173 return;
174
175 pr_debug("Validating PMD basic (%pGv)\n", ptr);
176 pmd = pfn_pmd(page_nr: args->fixed_pmd_pfn, pgprot: prot);
177
178 /*
179 * This test needs to be executed after the given page table entry
180 * is created with pfn_pmd() to make sure that vm_get_page_prot(idx)
181 * does not have the dirty bit enabled from the beginning. This is
182 * important for platforms like arm64 where (!PTE_RDONLY) indicate
183 * dirty bit being set.
184 */
185 WARN_ON(pmd_dirty(pmd_wrprotect(pmd)));
186
187
188 WARN_ON(!pmd_same(pmd, pmd));
189 WARN_ON(!pmd_young(pmd_mkyoung(pmd_mkold(pmd))));
190 WARN_ON(!pmd_dirty(pmd_mkdirty(pmd_mkclean(pmd))));
191 WARN_ON(!pmd_write(pmd_mkwrite(pmd_wrprotect(pmd), args->vma)));
192 WARN_ON(pmd_young(pmd_mkold(pmd_mkyoung(pmd))));
193 WARN_ON(pmd_dirty(pmd_mkclean(pmd_mkdirty(pmd))));
194 WARN_ON(pmd_write(pmd_wrprotect(pmd_mkwrite(pmd, args->vma))));
195 WARN_ON(pmd_dirty(pmd_wrprotect(pmd_mkclean(pmd))));
196 WARN_ON(!pmd_dirty(pmd_wrprotect(pmd_mkdirty(pmd))));
197 /*
198 * A huge page does not point to next level page table
199 * entry. Hence this must qualify as pmd_bad().
200 */
201 WARN_ON(!pmd_bad(pmd_mkhuge(pmd)));
202}
203
204static void __init pmd_advanced_tests(struct pgtable_debug_args *args)
205{
206 struct page *page;
207 pmd_t pmd;
208 unsigned long vaddr = args->vaddr;
209
210 if (!has_transparent_hugepage())
211 return;
212
213 page = (args->pmd_pfn != ULONG_MAX) ? pfn_to_page(args->pmd_pfn) : NULL;
214 if (!page)
215 return;
216
217 /*
218 * flush_dcache_page() is called after set_pmd_at() to clear
219 * PG_arch_1 for the page on ARM64. The page flag isn't cleared
220 * when it's released and page allocation check will fail when
221 * the page is allocated again. For architectures other than ARM64,
222 * the unexpected overhead of cache flushing is acceptable.
223 */
224 pr_debug("Validating PMD advanced\n");
225 /* Align the address wrt HPAGE_PMD_SIZE */
226 vaddr &= HPAGE_PMD_MASK;
227
228 pgtable_trans_huge_deposit(mm: args->mm, pmdp: args->pmdp, pgtable: args->start_ptep);
229
230 pmd = pfn_pmd(page_nr: args->pmd_pfn, pgprot: args->page_prot);
231 set_pmd_at(mm: args->mm, addr: vaddr, pmdp: args->pmdp, pmd);
232 flush_dcache_page(page);
233 pmdp_set_wrprotect(mm: args->mm, addr: vaddr, pmdp: args->pmdp);
234 pmd = pmdp_get(pmdp: args->pmdp);
235 WARN_ON(pmd_write(pmd));
236 pmdp_huge_get_and_clear(mm: args->mm, addr: vaddr, pmdp: args->pmdp);
237 pmd = pmdp_get(pmdp: args->pmdp);
238 WARN_ON(!pmd_none(pmd));
239
240 pmd = pfn_pmd(page_nr: args->pmd_pfn, pgprot: args->page_prot);
241 pmd = pmd_wrprotect(pmd);
242 pmd = pmd_mkclean(pmd);
243 set_pmd_at(mm: args->mm, addr: vaddr, pmdp: args->pmdp, pmd);
244 flush_dcache_page(page);
245 pmd = pmd_mkwrite(pmd, vma: args->vma);
246 pmd = pmd_mkdirty(pmd);
247 pmdp_set_access_flags(vma: args->vma, address: vaddr, pmdp: args->pmdp, entry: pmd, dirty: 1);
248 pmd = pmdp_get(pmdp: args->pmdp);
249 WARN_ON(!(pmd_write(pmd) && pmd_dirty(pmd)));
250 pmdp_huge_get_and_clear_full(vma: args->vma, address: vaddr, pmdp: args->pmdp, full: 1);
251 pmd = pmdp_get(pmdp: args->pmdp);
252 WARN_ON(!pmd_none(pmd));
253
254 pmd = pmd_mkhuge(pmd: pfn_pmd(page_nr: args->pmd_pfn, pgprot: args->page_prot));
255 pmd = pmd_mkyoung(pmd);
256 set_pmd_at(mm: args->mm, addr: vaddr, pmdp: args->pmdp, pmd);
257 flush_dcache_page(page);
258 pmdp_test_and_clear_young(vma: args->vma, addr: vaddr, pmdp: args->pmdp);
259 pmd = pmdp_get(pmdp: args->pmdp);
260 WARN_ON(pmd_young(pmd));
261
262 /* Clear the pte entries */
263 pmdp_huge_get_and_clear(mm: args->mm, addr: vaddr, pmdp: args->pmdp);
264 pgtable_trans_huge_withdraw(mm: args->mm, pmdp: args->pmdp);
265}
266
267static void __init pmd_leaf_tests(struct pgtable_debug_args *args)
268{
269 pmd_t pmd;
270
271 if (!has_transparent_hugepage())
272 return;
273
274 pr_debug("Validating PMD leaf\n");
275 pmd = pfn_pmd(page_nr: args->fixed_pmd_pfn, pgprot: args->page_prot);
276
277 /*
278 * PMD based THP is a leaf entry.
279 */
280 pmd = pmd_mkhuge(pmd);
281 WARN_ON(!pmd_leaf(pmd));
282}
283
284#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
285static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx)
286{
287 pgprot_t prot = vm_get_page_prot(vm_flags: idx);
288 unsigned long val = idx, *ptr = &val;
289 pud_t pud;
290
291 if (!has_transparent_pud_hugepage())
292 return;
293
294 pr_debug("Validating PUD basic (%pGv)\n", ptr);
295 pud = pfn_pud(page_nr: args->fixed_pud_pfn, pgprot: prot);
296
297 /*
298 * This test needs to be executed after the given page table entry
299 * is created with pfn_pud() to make sure that vm_get_page_prot(idx)
300 * does not have the dirty bit enabled from the beginning. This is
301 * important for platforms like arm64 where (!PTE_RDONLY) indicate
302 * dirty bit being set.
303 */
304 WARN_ON(pud_dirty(pud_wrprotect(pud)));
305
306 WARN_ON(!pud_same(pud, pud));
307 WARN_ON(!pud_young(pud_mkyoung(pud_mkold(pud))));
308 WARN_ON(!pud_dirty(pud_mkdirty(pud_mkclean(pud))));
309 WARN_ON(pud_dirty(pud_mkclean(pud_mkdirty(pud))));
310 WARN_ON(!pud_write(pud_mkwrite(pud_wrprotect(pud))));
311 WARN_ON(pud_write(pud_wrprotect(pud_mkwrite(pud))));
312 WARN_ON(pud_young(pud_mkold(pud_mkyoung(pud))));
313 WARN_ON(pud_dirty(pud_wrprotect(pud_mkclean(pud))));
314 WARN_ON(!pud_dirty(pud_wrprotect(pud_mkdirty(pud))));
315
316 if (mm_pmd_folded(args->mm))
317 return;
318
319 /*
320 * A huge page does not point to next level page table
321 * entry. Hence this must qualify as pud_bad().
322 */
323 WARN_ON(!pud_bad(pud_mkhuge(pud)));
324}
325
326static void __init pud_advanced_tests(struct pgtable_debug_args *args)
327{
328 struct page *page;
329 unsigned long vaddr = args->vaddr;
330 pud_t pud;
331
332 if (!has_transparent_pud_hugepage())
333 return;
334
335 page = (args->pud_pfn != ULONG_MAX) ? pfn_to_page(args->pud_pfn) : NULL;
336 if (!page)
337 return;
338
339 /*
340 * flush_dcache_page() is called after set_pud_at() to clear
341 * PG_arch_1 for the page on ARM64. The page flag isn't cleared
342 * when it's released and page allocation check will fail when
343 * the page is allocated again. For architectures other than ARM64,
344 * the unexpected overhead of cache flushing is acceptable.
345 */
346 pr_debug("Validating PUD advanced\n");
347 /* Align the address wrt HPAGE_PUD_SIZE */
348 vaddr &= HPAGE_PUD_MASK;
349
350 pud = pfn_pud(page_nr: args->pud_pfn, pgprot: args->page_prot);
351 /*
352 * Some architectures have debug checks to make sure
353 * huge pud mapping are only found with devmap entries
354 * For now test with only devmap entries.
355 */
356 pud = pud_mkdevmap(pud);
357 set_pud_at(mm: args->mm, addr: vaddr, pudp: args->pudp, pud);
358 flush_dcache_page(page);
359 pudp_set_wrprotect(mm: args->mm, address: vaddr, pudp: args->pudp);
360 pud = pudp_get(pudp: args->pudp);
361 WARN_ON(pud_write(pud));
362
363#ifndef __PAGETABLE_PMD_FOLDED
364 pudp_huge_get_and_clear(mm: args->mm, addr: vaddr, pudp: args->pudp);
365 pud = pudp_get(pudp: args->pudp);
366 WARN_ON(!pud_none(pud));
367#endif /* __PAGETABLE_PMD_FOLDED */
368 pud = pfn_pud(page_nr: args->pud_pfn, pgprot: args->page_prot);
369 pud = pud_mkdevmap(pud);
370 pud = pud_wrprotect(pud);
371 pud = pud_mkclean(pud);
372 set_pud_at(mm: args->mm, addr: vaddr, pudp: args->pudp, pud);
373 flush_dcache_page(page);
374 pud = pud_mkwrite(pud);
375 pud = pud_mkdirty(pud);
376 pudp_set_access_flags(vma: args->vma, address: vaddr, pudp: args->pudp, entry: pud, dirty: 1);
377 pud = pudp_get(pudp: args->pudp);
378 WARN_ON(!(pud_write(pud) && pud_dirty(pud)));
379
380#ifndef __PAGETABLE_PMD_FOLDED
381 pudp_huge_get_and_clear_full(vma: args->vma, address: vaddr, pudp: args->pudp, full: 1);
382 pud = pudp_get(pudp: args->pudp);
383 WARN_ON(!pud_none(pud));
384#endif /* __PAGETABLE_PMD_FOLDED */
385
386 pud = pfn_pud(page_nr: args->pud_pfn, pgprot: args->page_prot);
387 pud = pud_mkdevmap(pud);
388 pud = pud_mkyoung(pud);
389 set_pud_at(mm: args->mm, addr: vaddr, pudp: args->pudp, pud);
390 flush_dcache_page(page);
391 pudp_test_and_clear_young(vma: args->vma, addr: vaddr, pudp: args->pudp);
392 pud = pudp_get(pudp: args->pudp);
393 WARN_ON(pud_young(pud));
394
395 pudp_huge_get_and_clear(mm: args->mm, addr: vaddr, pudp: args->pudp);
396}
397
398static void __init pud_leaf_tests(struct pgtable_debug_args *args)
399{
400 pud_t pud;
401
402 if (!has_transparent_pud_hugepage())
403 return;
404
405 pr_debug("Validating PUD leaf\n");
406 pud = pfn_pud(page_nr: args->fixed_pud_pfn, pgprot: args->page_prot);
407 /*
408 * PUD based THP is a leaf entry.
409 */
410 pud = pud_mkhuge(pud);
411 WARN_ON(!pud_leaf(pud));
412}
413#else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
414static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx) { }
415static void __init pud_advanced_tests(struct pgtable_debug_args *args) { }
416static void __init pud_leaf_tests(struct pgtable_debug_args *args) { }
417#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
418#else /* !CONFIG_TRANSPARENT_HUGEPAGE */
419static void __init pmd_basic_tests(struct pgtable_debug_args *args, int idx) { }
420static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx) { }
421static void __init pmd_advanced_tests(struct pgtable_debug_args *args) { }
422static void __init pud_advanced_tests(struct pgtable_debug_args *args) { }
423static void __init pmd_leaf_tests(struct pgtable_debug_args *args) { }
424static void __init pud_leaf_tests(struct pgtable_debug_args *args) { }
425#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
426
427#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
428static void __init pmd_huge_tests(struct pgtable_debug_args *args)
429{
430 pmd_t pmd;
431
432 if (!arch_vmap_pmd_supported(prot: args->page_prot) ||
433 args->fixed_alignment < PMD_SIZE)
434 return;
435
436 pr_debug("Validating PMD huge\n");
437 /*
438 * X86 defined pmd_set_huge() verifies that the given
439 * PMD is not a populated non-leaf entry.
440 */
441 WRITE_ONCE(*args->pmdp, __pmd(0));
442 WARN_ON(!pmd_set_huge(args->pmdp, __pfn_to_phys(args->fixed_pmd_pfn), args->page_prot));
443 WARN_ON(!pmd_clear_huge(args->pmdp));
444 pmd = pmdp_get(pmdp: args->pmdp);
445 WARN_ON(!pmd_none(pmd));
446}
447
448static void __init pud_huge_tests(struct pgtable_debug_args *args)
449{
450 pud_t pud;
451
452 if (!arch_vmap_pud_supported(prot: args->page_prot) ||
453 args->fixed_alignment < PUD_SIZE)
454 return;
455
456 pr_debug("Validating PUD huge\n");
457 /*
458 * X86 defined pud_set_huge() verifies that the given
459 * PUD is not a populated non-leaf entry.
460 */
461 WRITE_ONCE(*args->pudp, __pud(0));
462 WARN_ON(!pud_set_huge(args->pudp, __pfn_to_phys(args->fixed_pud_pfn), args->page_prot));
463 WARN_ON(!pud_clear_huge(args->pudp));
464 pud = pudp_get(pudp: args->pudp);
465 WARN_ON(!pud_none(pud));
466}
467#else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
468static void __init pmd_huge_tests(struct pgtable_debug_args *args) { }
469static void __init pud_huge_tests(struct pgtable_debug_args *args) { }
470#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
471
472static void __init p4d_basic_tests(struct pgtable_debug_args *args)
473{
474 p4d_t p4d;
475
476 pr_debug("Validating P4D basic\n");
477 memset(&p4d, RANDOM_NZVALUE, sizeof(p4d_t));
478 WARN_ON(!p4d_same(p4d, p4d));
479}
480
481static void __init pgd_basic_tests(struct pgtable_debug_args *args)
482{
483 pgd_t pgd;
484
485 pr_debug("Validating PGD basic\n");
486 memset(&pgd, RANDOM_NZVALUE, sizeof(pgd_t));
487 WARN_ON(!pgd_same(pgd, pgd));
488}
489
490#ifndef __PAGETABLE_PUD_FOLDED
491static void __init pud_clear_tests(struct pgtable_debug_args *args)
492{
493 pud_t pud = pudp_get(pudp: args->pudp);
494
495 if (mm_pmd_folded(args->mm))
496 return;
497
498 pr_debug("Validating PUD clear\n");
499 WARN_ON(pud_none(pud));
500 pud_clear(pudp: args->pudp);
501 pud = pudp_get(pudp: args->pudp);
502 WARN_ON(!pud_none(pud));
503}
504
505static void __init pud_populate_tests(struct pgtable_debug_args *args)
506{
507 pud_t pud;
508
509 if (mm_pmd_folded(args->mm))
510 return;
511
512 pr_debug("Validating PUD populate\n");
513 /*
514 * This entry points to next level page table page.
515 * Hence this must not qualify as pud_bad().
516 */
517 pud_populate(mm: args->mm, pud: args->pudp, pmd: args->start_pmdp);
518 pud = pudp_get(pudp: args->pudp);
519 WARN_ON(pud_bad(pud));
520}
521#else /* !__PAGETABLE_PUD_FOLDED */
522static void __init pud_clear_tests(struct pgtable_debug_args *args) { }
523static void __init pud_populate_tests(struct pgtable_debug_args *args) { }
524#endif /* PAGETABLE_PUD_FOLDED */
525
526#ifndef __PAGETABLE_P4D_FOLDED
527static void __init p4d_clear_tests(struct pgtable_debug_args *args)
528{
529 p4d_t p4d = p4dp_get(p4dp: args->p4dp);
530
531 if (mm_pud_folded(args->mm))
532 return;
533
534 pr_debug("Validating P4D clear\n");
535 WARN_ON(p4d_none(p4d));
536 p4d_clear(p4dp: args->p4dp);
537 p4d = p4dp_get(p4dp: args->p4dp);
538 WARN_ON(!p4d_none(p4d));
539}
540
541static void __init p4d_populate_tests(struct pgtable_debug_args *args)
542{
543 p4d_t p4d;
544
545 if (mm_pud_folded(args->mm))
546 return;
547
548 pr_debug("Validating P4D populate\n");
549 /*
550 * This entry points to next level page table page.
551 * Hence this must not qualify as p4d_bad().
552 */
553 pud_clear(pudp: args->pudp);
554 p4d_clear(p4dp: args->p4dp);
555 p4d_populate(mm: args->mm, p4d: args->p4dp, pud: args->start_pudp);
556 p4d = p4dp_get(p4dp: args->p4dp);
557 WARN_ON(p4d_bad(p4d));
558}
559
560static void __init pgd_clear_tests(struct pgtable_debug_args *args)
561{
562 pgd_t pgd = pgdp_get(pgdp: args->pgdp);
563
564 if (mm_p4d_folded(mm: args->mm))
565 return;
566
567 pr_debug("Validating PGD clear\n");
568 WARN_ON(pgd_none(pgd));
569 pgd_clear(args->pgdp);
570 pgd = pgdp_get(pgdp: args->pgdp);
571 WARN_ON(!pgd_none(pgd));
572}
573
574static void __init pgd_populate_tests(struct pgtable_debug_args *args)
575{
576 pgd_t pgd;
577
578 if (mm_p4d_folded(mm: args->mm))
579 return;
580
581 pr_debug("Validating PGD populate\n");
582 /*
583 * This entry points to next level page table page.
584 * Hence this must not qualify as pgd_bad().
585 */
586 p4d_clear(p4dp: args->p4dp);
587 pgd_clear(args->pgdp);
588 pgd_populate(mm: args->mm, pgd: args->pgdp, p4d: args->start_p4dp);
589 pgd = pgdp_get(pgdp: args->pgdp);
590 WARN_ON(pgd_bad(pgd));
591}
592#else /* !__PAGETABLE_P4D_FOLDED */
593static void __init p4d_clear_tests(struct pgtable_debug_args *args) { }
594static void __init pgd_clear_tests(struct pgtable_debug_args *args) { }
595static void __init p4d_populate_tests(struct pgtable_debug_args *args) { }
596static void __init pgd_populate_tests(struct pgtable_debug_args *args) { }
597#endif /* PAGETABLE_P4D_FOLDED */
598
599static void __init pte_clear_tests(struct pgtable_debug_args *args)
600{
601 struct page *page;
602 pte_t pte = pfn_pte(page_nr: args->pte_pfn, pgprot: args->page_prot);
603
604 page = (args->pte_pfn != ULONG_MAX) ? pfn_to_page(args->pte_pfn) : NULL;
605 if (!page)
606 return;
607
608 /*
609 * flush_dcache_page() is called after set_pte_at() to clear
610 * PG_arch_1 for the page on ARM64. The page flag isn't cleared
611 * when it's released and page allocation check will fail when
612 * the page is allocated again. For architectures other than ARM64,
613 * the unexpected overhead of cache flushing is acceptable.
614 */
615 pr_debug("Validating PTE clear\n");
616 if (WARN_ON(!args->ptep))
617 return;
618
619 set_pte_at(args->mm, args->vaddr, args->ptep, pte);
620 WARN_ON(pte_none(pte));
621 flush_dcache_page(page);
622 barrier();
623 ptep_clear(mm: args->mm, addr: args->vaddr, ptep: args->ptep);
624 pte = ptep_get(ptep: args->ptep);
625 WARN_ON(!pte_none(pte));
626}
627
628static void __init pmd_clear_tests(struct pgtable_debug_args *args)
629{
630 pmd_t pmd = pmdp_get(pmdp: args->pmdp);
631
632 pr_debug("Validating PMD clear\n");
633 WARN_ON(pmd_none(pmd));
634 pmd_clear(pmdp: args->pmdp);
635 pmd = pmdp_get(pmdp: args->pmdp);
636 WARN_ON(!pmd_none(pmd));
637}
638
639static void __init pmd_populate_tests(struct pgtable_debug_args *args)
640{
641 pmd_t pmd;
642
643 pr_debug("Validating PMD populate\n");
644 /*
645 * This entry points to next level page table page.
646 * Hence this must not qualify as pmd_bad().
647 */
648 pmd_populate(mm: args->mm, pmd: args->pmdp, pte: args->start_ptep);
649 pmd = pmdp_get(pmdp: args->pmdp);
650 WARN_ON(pmd_bad(pmd));
651}
652
653static void __init pte_special_tests(struct pgtable_debug_args *args)
654{
655 pte_t pte = pfn_pte(page_nr: args->fixed_pte_pfn, pgprot: args->page_prot);
656
657 if (!IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL))
658 return;
659
660 pr_debug("Validating PTE special\n");
661 WARN_ON(!pte_special(pte_mkspecial(pte)));
662}
663
664static void __init pte_protnone_tests(struct pgtable_debug_args *args)
665{
666 pte_t pte = pfn_pte(page_nr: args->fixed_pte_pfn, pgprot: args->page_prot_none);
667
668 if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
669 return;
670
671 pr_debug("Validating PTE protnone\n");
672 WARN_ON(!pte_protnone(pte));
673 WARN_ON(!pte_present(pte));
674}
675
676#ifdef CONFIG_TRANSPARENT_HUGEPAGE
677static void __init pmd_protnone_tests(struct pgtable_debug_args *args)
678{
679 pmd_t pmd;
680
681 if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
682 return;
683
684 if (!has_transparent_hugepage())
685 return;
686
687 pr_debug("Validating PMD protnone\n");
688 pmd = pmd_mkhuge(pmd: pfn_pmd(page_nr: args->fixed_pmd_pfn, pgprot: args->page_prot_none));
689 WARN_ON(!pmd_protnone(pmd));
690 WARN_ON(!pmd_present(pmd));
691}
692#else /* !CONFIG_TRANSPARENT_HUGEPAGE */
693static void __init pmd_protnone_tests(struct pgtable_debug_args *args) { }
694#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
695
696#ifdef CONFIG_ARCH_HAS_PTE_DEVMAP
697static void __init pte_devmap_tests(struct pgtable_debug_args *args)
698{
699 pte_t pte = pfn_pte(page_nr: args->fixed_pte_pfn, pgprot: args->page_prot);
700
701 pr_debug("Validating PTE devmap\n");
702 WARN_ON(!pte_devmap(pte_mkdevmap(pte)));
703}
704
705#ifdef CONFIG_TRANSPARENT_HUGEPAGE
706static void __init pmd_devmap_tests(struct pgtable_debug_args *args)
707{
708 pmd_t pmd;
709
710 if (!has_transparent_hugepage())
711 return;
712
713 pr_debug("Validating PMD devmap\n");
714 pmd = pfn_pmd(page_nr: args->fixed_pmd_pfn, pgprot: args->page_prot);
715 WARN_ON(!pmd_devmap(pmd_mkdevmap(pmd)));
716}
717
718#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
719static void __init pud_devmap_tests(struct pgtable_debug_args *args)
720{
721 pud_t pud;
722
723 if (!has_transparent_pud_hugepage())
724 return;
725
726 pr_debug("Validating PUD devmap\n");
727 pud = pfn_pud(page_nr: args->fixed_pud_pfn, pgprot: args->page_prot);
728 WARN_ON(!pud_devmap(pud_mkdevmap(pud)));
729}
730#else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
731static void __init pud_devmap_tests(struct pgtable_debug_args *args) { }
732#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
733#else /* CONFIG_TRANSPARENT_HUGEPAGE */
734static void __init pmd_devmap_tests(struct pgtable_debug_args *args) { }
735static void __init pud_devmap_tests(struct pgtable_debug_args *args) { }
736#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
737#else
738static void __init pte_devmap_tests(struct pgtable_debug_args *args) { }
739static void __init pmd_devmap_tests(struct pgtable_debug_args *args) { }
740static void __init pud_devmap_tests(struct pgtable_debug_args *args) { }
741#endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */
742
743static void __init pte_soft_dirty_tests(struct pgtable_debug_args *args)
744{
745 pte_t pte = pfn_pte(page_nr: args->fixed_pte_pfn, pgprot: args->page_prot);
746
747 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
748 return;
749
750 pr_debug("Validating PTE soft dirty\n");
751 WARN_ON(!pte_soft_dirty(pte_mksoft_dirty(pte)));
752 WARN_ON(pte_soft_dirty(pte_clear_soft_dirty(pte)));
753}
754
755static void __init pte_swap_soft_dirty_tests(struct pgtable_debug_args *args)
756{
757 pte_t pte = pfn_pte(page_nr: args->fixed_pte_pfn, pgprot: args->page_prot);
758
759 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
760 return;
761
762 pr_debug("Validating PTE swap soft dirty\n");
763 WARN_ON(!pte_swp_soft_dirty(pte_swp_mksoft_dirty(pte)));
764 WARN_ON(pte_swp_soft_dirty(pte_swp_clear_soft_dirty(pte)));
765}
766
767#ifdef CONFIG_TRANSPARENT_HUGEPAGE
768static void __init pmd_soft_dirty_tests(struct pgtable_debug_args *args)
769{
770 pmd_t pmd;
771
772 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
773 return;
774
775 if (!has_transparent_hugepage())
776 return;
777
778 pr_debug("Validating PMD soft dirty\n");
779 pmd = pfn_pmd(page_nr: args->fixed_pmd_pfn, pgprot: args->page_prot);
780 WARN_ON(!pmd_soft_dirty(pmd_mksoft_dirty(pmd)));
781 WARN_ON(pmd_soft_dirty(pmd_clear_soft_dirty(pmd)));
782}
783
784static void __init pmd_swap_soft_dirty_tests(struct pgtable_debug_args *args)
785{
786 pmd_t pmd;
787
788 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY) ||
789 !IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION))
790 return;
791
792 if (!has_transparent_hugepage())
793 return;
794
795 pr_debug("Validating PMD swap soft dirty\n");
796 pmd = pfn_pmd(page_nr: args->fixed_pmd_pfn, pgprot: args->page_prot);
797 WARN_ON(!pmd_swp_soft_dirty(pmd_swp_mksoft_dirty(pmd)));
798 WARN_ON(pmd_swp_soft_dirty(pmd_swp_clear_soft_dirty(pmd)));
799}
800#else /* !CONFIG_TRANSPARENT_HUGEPAGE */
801static void __init pmd_soft_dirty_tests(struct pgtable_debug_args *args) { }
802static void __init pmd_swap_soft_dirty_tests(struct pgtable_debug_args *args) { }
803#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
804
805static void __init pte_swap_exclusive_tests(struct pgtable_debug_args *args)
806{
807 unsigned long max_swap_offset;
808 swp_entry_t entry, entry2;
809 pte_t pte;
810
811 pr_debug("Validating PTE swap exclusive\n");
812
813 /* See generic_max_swapfile_size(): probe the maximum offset */
814 max_swap_offset = swp_offset(entry: pte_to_swp_entry(pte: swp_entry_to_pte(entry: swp_entry(type: 0, offset: ~0UL))));
815
816 /* Create a swp entry with all possible bits set */
817 entry = swp_entry(type: (1 << MAX_SWAPFILES_SHIFT) - 1, offset: max_swap_offset);
818
819 pte = swp_entry_to_pte(entry);
820 WARN_ON(pte_swp_exclusive(pte));
821 WARN_ON(!is_swap_pte(pte));
822 entry2 = pte_to_swp_entry(pte);
823 WARN_ON(memcmp(&entry, &entry2, sizeof(entry)));
824
825 pte = pte_swp_mkexclusive(pte);
826 WARN_ON(!pte_swp_exclusive(pte));
827 WARN_ON(!is_swap_pte(pte));
828 WARN_ON(pte_swp_soft_dirty(pte));
829 entry2 = pte_to_swp_entry(pte);
830 WARN_ON(memcmp(&entry, &entry2, sizeof(entry)));
831
832 pte = pte_swp_clear_exclusive(pte);
833 WARN_ON(pte_swp_exclusive(pte));
834 WARN_ON(!is_swap_pte(pte));
835 entry2 = pte_to_swp_entry(pte);
836 WARN_ON(memcmp(&entry, &entry2, sizeof(entry)));
837}
838
839static void __init pte_swap_tests(struct pgtable_debug_args *args)
840{
841 swp_entry_t swp;
842 pte_t pte;
843
844 pr_debug("Validating PTE swap\n");
845 pte = pfn_pte(page_nr: args->fixed_pte_pfn, pgprot: args->page_prot);
846 swp = __pte_to_swp_entry(pte);
847 pte = __swp_entry_to_pte(swp);
848 WARN_ON(args->fixed_pte_pfn != pte_pfn(pte));
849}
850
851#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
852static void __init pmd_swap_tests(struct pgtable_debug_args *args)
853{
854 swp_entry_t swp;
855 pmd_t pmd;
856
857 if (!has_transparent_hugepage())
858 return;
859
860 pr_debug("Validating PMD swap\n");
861 pmd = pfn_pmd(page_nr: args->fixed_pmd_pfn, pgprot: args->page_prot);
862 swp = __pmd_to_swp_entry(pmd);
863 pmd = __swp_entry_to_pmd(swp);
864 WARN_ON(args->fixed_pmd_pfn != pmd_pfn(pmd));
865}
866#else /* !CONFIG_ARCH_ENABLE_THP_MIGRATION */
867static void __init pmd_swap_tests(struct pgtable_debug_args *args) { }
868#endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
869
870static void __init swap_migration_tests(struct pgtable_debug_args *args)
871{
872 struct page *page;
873 swp_entry_t swp;
874
875 if (!IS_ENABLED(CONFIG_MIGRATION))
876 return;
877
878 /*
879 * swap_migration_tests() requires a dedicated page as it needs to
880 * be locked before creating a migration entry from it. Locking the
881 * page that actually maps kernel text ('start_kernel') can be real
882 * problematic. Lets use the allocated page explicitly for this
883 * purpose.
884 */
885 page = (args->pte_pfn != ULONG_MAX) ? pfn_to_page(args->pte_pfn) : NULL;
886 if (!page)
887 return;
888
889 pr_debug("Validating swap migration\n");
890
891 /*
892 * make_[readable|writable]_migration_entry() expects given page to
893 * be locked, otherwise it stumbles upon a BUG_ON().
894 */
895 __SetPageLocked(page);
896 swp = make_writable_migration_entry(page_to_pfn(page));
897 WARN_ON(!is_migration_entry(swp));
898 WARN_ON(!is_writable_migration_entry(swp));
899
900 swp = make_readable_migration_entry(offset: swp_offset(entry: swp));
901 WARN_ON(!is_migration_entry(swp));
902 WARN_ON(is_writable_migration_entry(swp));
903
904 swp = make_readable_migration_entry(page_to_pfn(page));
905 WARN_ON(!is_migration_entry(swp));
906 WARN_ON(is_writable_migration_entry(swp));
907 __ClearPageLocked(page);
908}
909
910#ifdef CONFIG_HUGETLB_PAGE
911static void __init hugetlb_basic_tests(struct pgtable_debug_args *args)
912{
913 pte_t pte;
914
915 pr_debug("Validating HugeTLB basic\n");
916 pte = pfn_pte(page_nr: args->fixed_pmd_pfn, pgprot: args->page_prot);
917 pte = arch_make_huge_pte(entry: pte, PMD_SHIFT, VM_ACCESS_FLAGS);
918
919#ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB
920 WARN_ON(!pte_huge(pte));
921#endif
922 WARN_ON(!huge_pte_dirty(huge_pte_mkdirty(pte)));
923 WARN_ON(!huge_pte_write(huge_pte_mkwrite(huge_pte_wrprotect(pte))));
924 WARN_ON(huge_pte_write(huge_pte_wrprotect(huge_pte_mkwrite(pte))));
925}
926#else /* !CONFIG_HUGETLB_PAGE */
927static void __init hugetlb_basic_tests(struct pgtable_debug_args *args) { }
928#endif /* CONFIG_HUGETLB_PAGE */
929
930#ifdef CONFIG_TRANSPARENT_HUGEPAGE
931static void __init pmd_thp_tests(struct pgtable_debug_args *args)
932{
933 pmd_t pmd;
934
935 if (!has_transparent_hugepage())
936 return;
937
938 pr_debug("Validating PMD based THP\n");
939 /*
940 * pmd_trans_huge() and pmd_present() must return positive after
941 * MMU invalidation with pmd_mkinvalid(). This behavior is an
942 * optimization for transparent huge page. pmd_trans_huge() must
943 * be true if pmd_page() returns a valid THP to avoid taking the
944 * pmd_lock when others walk over non transhuge pmds (i.e. there
945 * are no THP allocated). Especially when splitting a THP and
946 * removing the present bit from the pmd, pmd_trans_huge() still
947 * needs to return true. pmd_present() should be true whenever
948 * pmd_trans_huge() returns true.
949 */
950 pmd = pfn_pmd(page_nr: args->fixed_pmd_pfn, pgprot: args->page_prot);
951 WARN_ON(!pmd_trans_huge(pmd_mkhuge(pmd)));
952
953#ifndef __HAVE_ARCH_PMDP_INVALIDATE
954 WARN_ON(!pmd_trans_huge(pmd_mkinvalid(pmd_mkhuge(pmd))));
955 WARN_ON(!pmd_present(pmd_mkinvalid(pmd_mkhuge(pmd))));
956 WARN_ON(!pmd_leaf(pmd_mkinvalid(pmd_mkhuge(pmd))));
957#endif /* __HAVE_ARCH_PMDP_INVALIDATE */
958}
959
960#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
961static void __init pud_thp_tests(struct pgtable_debug_args *args)
962{
963 pud_t pud;
964
965 if (!has_transparent_pud_hugepage())
966 return;
967
968 pr_debug("Validating PUD based THP\n");
969 pud = pfn_pud(page_nr: args->fixed_pud_pfn, pgprot: args->page_prot);
970 WARN_ON(!pud_trans_huge(pud_mkhuge(pud)));
971
972 /*
973 * pud_mkinvalid() has been dropped for now. Enable back
974 * these tests when it comes back with a modified pud_present().
975 *
976 * WARN_ON(!pud_trans_huge(pud_mkinvalid(pud_mkhuge(pud))));
977 * WARN_ON(!pud_present(pud_mkinvalid(pud_mkhuge(pud))));
978 */
979}
980#else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
981static void __init pud_thp_tests(struct pgtable_debug_args *args) { }
982#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
983#else /* !CONFIG_TRANSPARENT_HUGEPAGE */
984static void __init pmd_thp_tests(struct pgtable_debug_args *args) { }
985static void __init pud_thp_tests(struct pgtable_debug_args *args) { }
986#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
987
988static unsigned long __init get_random_vaddr(void)
989{
990 unsigned long random_vaddr, random_pages, total_user_pages;
991
992 total_user_pages = (TASK_SIZE - FIRST_USER_ADDRESS) / PAGE_SIZE;
993
994 random_pages = get_random_long() % total_user_pages;
995 random_vaddr = FIRST_USER_ADDRESS + random_pages * PAGE_SIZE;
996
997 return random_vaddr;
998}
999
1000static void __init destroy_args(struct pgtable_debug_args *args)
1001{
1002 struct page *page = NULL;
1003
1004 /* Free (huge) page */
1005 if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
1006 has_transparent_pud_hugepage() &&
1007 args->pud_pfn != ULONG_MAX) {
1008 if (args->is_contiguous_page) {
1009 free_contig_range(pfn: args->pud_pfn,
1010 nr_pages: (1 << (HPAGE_PUD_SHIFT - PAGE_SHIFT)));
1011 } else {
1012 page = pfn_to_page(args->pud_pfn);
1013 __free_pages(page, HPAGE_PUD_SHIFT - PAGE_SHIFT);
1014 }
1015
1016 args->pud_pfn = ULONG_MAX;
1017 args->pmd_pfn = ULONG_MAX;
1018 args->pte_pfn = ULONG_MAX;
1019 }
1020
1021 if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
1022 has_transparent_hugepage() &&
1023 args->pmd_pfn != ULONG_MAX) {
1024 if (args->is_contiguous_page) {
1025 free_contig_range(pfn: args->pmd_pfn, nr_pages: (1 << HPAGE_PMD_ORDER));
1026 } else {
1027 page = pfn_to_page(args->pmd_pfn);
1028 __free_pages(page, HPAGE_PMD_ORDER);
1029 }
1030
1031 args->pmd_pfn = ULONG_MAX;
1032 args->pte_pfn = ULONG_MAX;
1033 }
1034
1035 if (args->pte_pfn != ULONG_MAX) {
1036 page = pfn_to_page(args->pte_pfn);
1037 __free_page(page);
1038
1039 args->pte_pfn = ULONG_MAX;
1040 }
1041
1042 /* Free page table entries */
1043 if (args->start_ptep) {
1044 pte_free(mm: args->mm, pte_page: args->start_ptep);
1045 mm_dec_nr_ptes(mm: args->mm);
1046 }
1047
1048 if (args->start_pmdp) {
1049 pmd_free(mm: args->mm, pmd: args->start_pmdp);
1050 mm_dec_nr_pmds(mm: args->mm);
1051 }
1052
1053 if (args->start_pudp) {
1054 pud_free(mm: args->mm, pud: args->start_pudp);
1055 mm_dec_nr_puds(mm: args->mm);
1056 }
1057
1058 if (args->start_p4dp)
1059 p4d_free(mm: args->mm, p4d: args->start_p4dp);
1060
1061 /* Free vma and mm struct */
1062 if (args->vma)
1063 vm_area_free(args->vma);
1064
1065 if (args->mm)
1066 mmdrop(mm: args->mm);
1067}
1068
1069static struct page * __init
1070debug_vm_pgtable_alloc_huge_page(struct pgtable_debug_args *args, int order)
1071{
1072 struct page *page = NULL;
1073
1074#ifdef CONFIG_CONTIG_ALLOC
1075 if (order > MAX_PAGE_ORDER) {
1076 page = alloc_contig_pages((1 << order), GFP_KERNEL,
1077 first_online_node, NULL);
1078 if (page) {
1079 args->is_contiguous_page = true;
1080 return page;
1081 }
1082 }
1083#endif
1084
1085 if (order <= MAX_PAGE_ORDER)
1086 page = alloc_pages(GFP_KERNEL, order);
1087
1088 return page;
1089}
1090
1091/*
1092 * Check if a physical memory range described by <pstart, pend> contains
1093 * an area that is of size psize, and aligned to psize.
1094 *
1095 * Don't use address 0, an all-zeroes physical address might mask bugs, and
1096 * it's not used on x86.
1097 */
1098static void __init phys_align_check(phys_addr_t pstart,
1099 phys_addr_t pend, unsigned long psize,
1100 phys_addr_t *physp, unsigned long *alignp)
1101{
1102 phys_addr_t aligned_start, aligned_end;
1103
1104 if (pstart == 0)
1105 pstart = PAGE_SIZE;
1106
1107 aligned_start = ALIGN(pstart, psize);
1108 aligned_end = aligned_start + psize;
1109
1110 if (aligned_end > aligned_start && aligned_end <= pend) {
1111 *alignp = psize;
1112 *physp = aligned_start;
1113 }
1114}
1115
1116static void __init init_fixed_pfns(struct pgtable_debug_args *args)
1117{
1118 u64 idx;
1119 phys_addr_t phys, pstart, pend;
1120
1121 /*
1122 * Initialize the fixed pfns. To do this, try to find a
1123 * valid physical range, preferably aligned to PUD_SIZE,
1124 * but settling for aligned to PMD_SIZE as a fallback. If
1125 * neither of those is found, use the physical address of
1126 * the start_kernel symbol.
1127 *
1128 * The memory doesn't need to be allocated, it just needs to exist
1129 * as usable memory. It won't be touched.
1130 *
1131 * The alignment is recorded, and can be checked to see if we
1132 * can run the tests that require an actual valid physical
1133 * address range on some architectures ({pmd,pud}_huge_test
1134 * on x86).
1135 */
1136
1137 phys = __pa_symbol(&start_kernel);
1138 args->fixed_alignment = PAGE_SIZE;
1139
1140 for_each_mem_range(idx, &pstart, &pend) {
1141 /* First check for a PUD-aligned area */
1142 phys_align_check(pstart, pend, PUD_SIZE, physp: &phys,
1143 alignp: &args->fixed_alignment);
1144
1145 /* If a PUD-aligned area is found, we're done */
1146 if (args->fixed_alignment == PUD_SIZE)
1147 break;
1148
1149 /*
1150 * If no PMD-aligned area found yet, check for one,
1151 * but continue the loop to look for a PUD-aligned area.
1152 */
1153 if (args->fixed_alignment < PMD_SIZE)
1154 phys_align_check(pstart, pend, PMD_SIZE, physp: &phys,
1155 alignp: &args->fixed_alignment);
1156 }
1157
1158 args->fixed_pgd_pfn = __phys_to_pfn(phys & PGDIR_MASK);
1159 args->fixed_p4d_pfn = __phys_to_pfn(phys & P4D_MASK);
1160 args->fixed_pud_pfn = __phys_to_pfn(phys & PUD_MASK);
1161 args->fixed_pmd_pfn = __phys_to_pfn(phys & PMD_MASK);
1162 args->fixed_pte_pfn = __phys_to_pfn(phys & PAGE_MASK);
1163 WARN_ON(!pfn_valid(args->fixed_pte_pfn));
1164}
1165
1166
1167static int __init init_args(struct pgtable_debug_args *args)
1168{
1169 struct page *page = NULL;
1170 int ret = 0;
1171
1172 /*
1173 * Initialize the debugging data.
1174 *
1175 * vm_get_page_prot(VM_NONE) or vm_get_page_prot(VM_SHARED|VM_NONE)
1176 * will help create page table entries with PROT_NONE permission as
1177 * required for pxx_protnone_tests().
1178 */
1179 memset(args, 0, sizeof(*args));
1180 args->vaddr = get_random_vaddr();
1181 args->page_prot = vm_get_page_prot(VM_ACCESS_FLAGS);
1182 args->page_prot_none = vm_get_page_prot(VM_NONE);
1183 args->is_contiguous_page = false;
1184 args->pud_pfn = ULONG_MAX;
1185 args->pmd_pfn = ULONG_MAX;
1186 args->pte_pfn = ULONG_MAX;
1187 args->fixed_pgd_pfn = ULONG_MAX;
1188 args->fixed_p4d_pfn = ULONG_MAX;
1189 args->fixed_pud_pfn = ULONG_MAX;
1190 args->fixed_pmd_pfn = ULONG_MAX;
1191 args->fixed_pte_pfn = ULONG_MAX;
1192
1193 /* Allocate mm and vma */
1194 args->mm = mm_alloc();
1195 if (!args->mm) {
1196 pr_err("Failed to allocate mm struct\n");
1197 ret = -ENOMEM;
1198 goto error;
1199 }
1200
1201 args->vma = vm_area_alloc(args->mm);
1202 if (!args->vma) {
1203 pr_err("Failed to allocate vma\n");
1204 ret = -ENOMEM;
1205 goto error;
1206 }
1207
1208 /*
1209 * Allocate page table entries. They will be modified in the tests.
1210 * Lets save the page table entries so that they can be released
1211 * when the tests are completed.
1212 */
1213 args->pgdp = pgd_offset(args->mm, args->vaddr);
1214 args->p4dp = p4d_alloc(mm: args->mm, pgd: args->pgdp, address: args->vaddr);
1215 if (!args->p4dp) {
1216 pr_err("Failed to allocate p4d entries\n");
1217 ret = -ENOMEM;
1218 goto error;
1219 }
1220 args->start_p4dp = p4d_offset(pgd: args->pgdp, address: 0UL);
1221 WARN_ON(!args->start_p4dp);
1222
1223 args->pudp = pud_alloc(mm: args->mm, p4d: args->p4dp, address: args->vaddr);
1224 if (!args->pudp) {
1225 pr_err("Failed to allocate pud entries\n");
1226 ret = -ENOMEM;
1227 goto error;
1228 }
1229 args->start_pudp = pud_offset(p4d: args->p4dp, address: 0UL);
1230 WARN_ON(!args->start_pudp);
1231
1232 args->pmdp = pmd_alloc(mm: args->mm, pud: args->pudp, address: args->vaddr);
1233 if (!args->pmdp) {
1234 pr_err("Failed to allocate pmd entries\n");
1235 ret = -ENOMEM;
1236 goto error;
1237 }
1238 args->start_pmdp = pmd_offset(pud: args->pudp, address: 0UL);
1239 WARN_ON(!args->start_pmdp);
1240
1241 if (pte_alloc(args->mm, args->pmdp)) {
1242 pr_err("Failed to allocate pte entries\n");
1243 ret = -ENOMEM;
1244 goto error;
1245 }
1246 args->start_ptep = pmd_pgtable(pmdp_get(args->pmdp));
1247 WARN_ON(!args->start_ptep);
1248
1249 init_fixed_pfns(args);
1250
1251 /*
1252 * Allocate (huge) pages because some of the tests need to access
1253 * the data in the pages. The corresponding tests will be skipped
1254 * if we fail to allocate (huge) pages.
1255 */
1256 if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
1257 has_transparent_pud_hugepage()) {
1258 page = debug_vm_pgtable_alloc_huge_page(args,
1259 HPAGE_PUD_SHIFT - PAGE_SHIFT);
1260 if (page) {
1261 args->pud_pfn = page_to_pfn(page);
1262 args->pmd_pfn = args->pud_pfn;
1263 args->pte_pfn = args->pud_pfn;
1264 return 0;
1265 }
1266 }
1267
1268 if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
1269 has_transparent_hugepage()) {
1270 page = debug_vm_pgtable_alloc_huge_page(args, HPAGE_PMD_ORDER);
1271 if (page) {
1272 args->pmd_pfn = page_to_pfn(page);
1273 args->pte_pfn = args->pmd_pfn;
1274 return 0;
1275 }
1276 }
1277
1278 page = alloc_page(GFP_KERNEL);
1279 if (page)
1280 args->pte_pfn = page_to_pfn(page);
1281
1282 return 0;
1283
1284error:
1285 destroy_args(args);
1286 return ret;
1287}
1288
1289static int __init debug_vm_pgtable(void)
1290{
1291 struct pgtable_debug_args args;
1292 spinlock_t *ptl = NULL;
1293 int idx, ret;
1294
1295 pr_info("Validating architecture page table helpers\n");
1296 ret = init_args(args: &args);
1297 if (ret)
1298 return ret;
1299
1300 /*
1301 * Iterate over each possible vm_flags to make sure that all
1302 * the basic page table transformation validations just hold
1303 * true irrespective of the starting protection value for a
1304 * given page table entry.
1305 *
1306 * Protection based vm_flags combinations are always linear
1307 * and increasing i.e starting from VM_NONE and going up to
1308 * (VM_SHARED | READ | WRITE | EXEC).
1309 */
1310#define VM_FLAGS_START (VM_NONE)
1311#define VM_FLAGS_END (VM_SHARED | VM_EXEC | VM_WRITE | VM_READ)
1312
1313 for (idx = VM_FLAGS_START; idx <= VM_FLAGS_END; idx++) {
1314 pte_basic_tests(args: &args, idx);
1315 pmd_basic_tests(args: &args, idx);
1316 pud_basic_tests(args: &args, idx);
1317 }
1318
1319 /*
1320 * Both P4D and PGD level tests are very basic which do not
1321 * involve creating page table entries from the protection
1322 * value and the given pfn. Hence just keep them out from
1323 * the above iteration for now to save some test execution
1324 * time.
1325 */
1326 p4d_basic_tests(args: &args);
1327 pgd_basic_tests(args: &args);
1328
1329 pmd_leaf_tests(args: &args);
1330 pud_leaf_tests(args: &args);
1331
1332 pte_special_tests(args: &args);
1333 pte_protnone_tests(args: &args);
1334 pmd_protnone_tests(args: &args);
1335
1336 pte_devmap_tests(args: &args);
1337 pmd_devmap_tests(args: &args);
1338 pud_devmap_tests(args: &args);
1339
1340 pte_soft_dirty_tests(args: &args);
1341 pmd_soft_dirty_tests(args: &args);
1342 pte_swap_soft_dirty_tests(args: &args);
1343 pmd_swap_soft_dirty_tests(args: &args);
1344
1345 pte_swap_exclusive_tests(args: &args);
1346
1347 pte_swap_tests(args: &args);
1348 pmd_swap_tests(args: &args);
1349
1350 swap_migration_tests(args: &args);
1351
1352 pmd_thp_tests(args: &args);
1353 pud_thp_tests(args: &args);
1354
1355 hugetlb_basic_tests(args: &args);
1356
1357 /*
1358 * Page table modifying tests. They need to hold
1359 * proper page table lock.
1360 */
1361
1362 args.ptep = pte_offset_map_lock(mm: args.mm, pmd: args.pmdp, addr: args.vaddr, ptlp: &ptl);
1363 pte_clear_tests(args: &args);
1364 pte_advanced_tests(args: &args);
1365 if (args.ptep)
1366 pte_unmap_unlock(args.ptep, ptl);
1367
1368 ptl = pmd_lock(mm: args.mm, pmd: args.pmdp);
1369 pmd_clear_tests(args: &args);
1370 pmd_advanced_tests(args: &args);
1371 pmd_huge_tests(args: &args);
1372 pmd_populate_tests(args: &args);
1373 spin_unlock(lock: ptl);
1374
1375 ptl = pud_lock(mm: args.mm, pud: args.pudp);
1376 pud_clear_tests(args: &args);
1377 pud_advanced_tests(args: &args);
1378 pud_huge_tests(args: &args);
1379 pud_populate_tests(args: &args);
1380 spin_unlock(lock: ptl);
1381
1382 spin_lock(lock: &(args.mm->page_table_lock));
1383 p4d_clear_tests(args: &args);
1384 pgd_clear_tests(args: &args);
1385 p4d_populate_tests(args: &args);
1386 pgd_populate_tests(args: &args);
1387 spin_unlock(lock: &(args.mm->page_table_lock));
1388
1389 destroy_args(args: &args);
1390 return 0;
1391}
1392late_initcall(debug_vm_pgtable);
1393

source code of linux/mm/debug_vm_pgtable.c

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