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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * linux/mm/madvise.c | |
4 | * | |
5 | * Copyright (C) 1999 Linus Torvalds | |
6 | * Copyright (C) 2002 Christoph Hellwig | |
7 | */ | |
8 | ||
9 | #include <linux/mman.h> | |
10 | #include <linux/pagemap.h> | |
11 | #include <linux/syscalls.h> | |
05b74384 | 12 | #include <linux/mempolicy.h> |
afcf938e | 13 | #include <linux/page-isolation.h> |
9c276cc6 | 14 | #include <linux/page_idle.h> |
05ce7724 | 15 | #include <linux/userfaultfd_k.h> |
1da177e4 | 16 | #include <linux/hugetlb.h> |
3f31d075 | 17 | #include <linux/falloc.h> |
692fe624 | 18 | #include <linux/fadvise.h> |
e8edc6e0 | 19 | #include <linux/sched.h> |
f8af4da3 | 20 | #include <linux/ksm.h> |
3f31d075 | 21 | #include <linux/fs.h> |
9ab4233d | 22 | #include <linux/file.h> |
1998cc04 | 23 | #include <linux/blkdev.h> |
66114cad | 24 | #include <linux/backing-dev.h> |
a520110e | 25 | #include <linux/pagewalk.h> |
1998cc04 SL |
26 | #include <linux/swap.h> |
27 | #include <linux/swapops.h> | |
3a4f8a0b | 28 | #include <linux/shmem_fs.h> |
854e9ed0 | 29 | #include <linux/mmu_notifier.h> |
bc0c4d1e | 30 | #include <linux/sched/mm.h> |
854e9ed0 MK |
31 | |
32 | #include <asm/tlb.h> | |
1da177e4 | 33 | |
23519073 KS |
34 | #include "internal.h" |
35 | ||
d616d512 MK |
36 | struct madvise_walk_private { |
37 | struct mmu_gather *tlb; | |
38 | bool pageout; | |
39 | }; | |
40 | ||
0a27a14a NP |
41 | /* |
42 | * Any behaviour which results in changes to the vma->vm_flags needs to | |
c1e8d7c6 | 43 | * take mmap_lock for writing. Others, which simply traverse vmas, need |
0a27a14a NP |
44 | * to only take it for reading. |
45 | */ | |
46 | static int madvise_need_mmap_write(int behavior) | |
47 | { | |
48 | switch (behavior) { | |
49 | case MADV_REMOVE: | |
50 | case MADV_WILLNEED: | |
51 | case MADV_DONTNEED: | |
9c276cc6 | 52 | case MADV_COLD: |
1a4e58cc | 53 | case MADV_PAGEOUT: |
854e9ed0 | 54 | case MADV_FREE: |
0a27a14a NP |
55 | return 0; |
56 | default: | |
57 | /* be safe, default to 1. list exceptions explicitly */ | |
58 | return 1; | |
59 | } | |
60 | } | |
61 | ||
1da177e4 LT |
62 | /* |
63 | * We can potentially split a vm area into separate | |
64 | * areas, each area with its own behavior. | |
65 | */ | |
ec9bed9d | 66 | static long madvise_behavior(struct vm_area_struct *vma, |
05b74384 PM |
67 | struct vm_area_struct **prev, |
68 | unsigned long start, unsigned long end, int behavior) | |
1da177e4 | 69 | { |
ec9bed9d | 70 | struct mm_struct *mm = vma->vm_mm; |
1da177e4 | 71 | int error = 0; |
05b74384 | 72 | pgoff_t pgoff; |
3866ea90 | 73 | unsigned long new_flags = vma->vm_flags; |
e798c6e8 PM |
74 | |
75 | switch (behavior) { | |
f8225661 MT |
76 | case MADV_NORMAL: |
77 | new_flags = new_flags & ~VM_RAND_READ & ~VM_SEQ_READ; | |
78 | break; | |
e798c6e8 | 79 | case MADV_SEQUENTIAL: |
f8225661 | 80 | new_flags = (new_flags & ~VM_RAND_READ) | VM_SEQ_READ; |
e798c6e8 PM |
81 | break; |
82 | case MADV_RANDOM: | |
f8225661 | 83 | new_flags = (new_flags & ~VM_SEQ_READ) | VM_RAND_READ; |
e798c6e8 | 84 | break; |
f8225661 MT |
85 | case MADV_DONTFORK: |
86 | new_flags |= VM_DONTCOPY; | |
87 | break; | |
88 | case MADV_DOFORK: | |
3866ea90 HD |
89 | if (vma->vm_flags & VM_IO) { |
90 | error = -EINVAL; | |
91 | goto out; | |
92 | } | |
f8225661 | 93 | new_flags &= ~VM_DONTCOPY; |
e798c6e8 | 94 | break; |
d2cd9ede RR |
95 | case MADV_WIPEONFORK: |
96 | /* MADV_WIPEONFORK is only supported on anonymous memory. */ | |
97 | if (vma->vm_file || vma->vm_flags & VM_SHARED) { | |
98 | error = -EINVAL; | |
99 | goto out; | |
100 | } | |
101 | new_flags |= VM_WIPEONFORK; | |
102 | break; | |
103 | case MADV_KEEPONFORK: | |
104 | new_flags &= ~VM_WIPEONFORK; | |
105 | break; | |
accb61fe | 106 | case MADV_DONTDUMP: |
0103bd16 | 107 | new_flags |= VM_DONTDUMP; |
accb61fe JB |
108 | break; |
109 | case MADV_DODUMP: | |
d41aa525 | 110 | if (!is_vm_hugetlb_page(vma) && new_flags & VM_SPECIAL) { |
0103bd16 KK |
111 | error = -EINVAL; |
112 | goto out; | |
113 | } | |
114 | new_flags &= ~VM_DONTDUMP; | |
accb61fe | 115 | break; |
f8af4da3 HD |
116 | case MADV_MERGEABLE: |
117 | case MADV_UNMERGEABLE: | |
118 | error = ksm_madvise(vma, start, end, behavior, &new_flags); | |
f3bc0dba MR |
119 | if (error) |
120 | goto out_convert_errno; | |
f8af4da3 | 121 | break; |
0af4e98b | 122 | case MADV_HUGEPAGE: |
a664b2d8 | 123 | case MADV_NOHUGEPAGE: |
60ab3244 | 124 | error = hugepage_madvise(vma, &new_flags, behavior); |
f3bc0dba MR |
125 | if (error) |
126 | goto out_convert_errno; | |
0af4e98b | 127 | break; |
e798c6e8 PM |
128 | } |
129 | ||
05b74384 PM |
130 | if (new_flags == vma->vm_flags) { |
131 | *prev = vma; | |
836d5ffd | 132 | goto out; |
05b74384 PM |
133 | } |
134 | ||
135 | pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); | |
136 | *prev = vma_merge(mm, *prev, start, end, new_flags, vma->anon_vma, | |
19a809af AA |
137 | vma->vm_file, pgoff, vma_policy(vma), |
138 | vma->vm_userfaultfd_ctx); | |
05b74384 PM |
139 | if (*prev) { |
140 | vma = *prev; | |
141 | goto success; | |
142 | } | |
143 | ||
144 | *prev = vma; | |
1da177e4 LT |
145 | |
146 | if (start != vma->vm_start) { | |
def5efe0 DR |
147 | if (unlikely(mm->map_count >= sysctl_max_map_count)) { |
148 | error = -ENOMEM; | |
1da177e4 | 149 | goto out; |
def5efe0 DR |
150 | } |
151 | error = __split_vma(mm, vma, start, 1); | |
f3bc0dba MR |
152 | if (error) |
153 | goto out_convert_errno; | |
1da177e4 LT |
154 | } |
155 | ||
156 | if (end != vma->vm_end) { | |
def5efe0 DR |
157 | if (unlikely(mm->map_count >= sysctl_max_map_count)) { |
158 | error = -ENOMEM; | |
1da177e4 | 159 | goto out; |
def5efe0 DR |
160 | } |
161 | error = __split_vma(mm, vma, end, 0); | |
f3bc0dba MR |
162 | if (error) |
163 | goto out_convert_errno; | |
1da177e4 LT |
164 | } |
165 | ||
836d5ffd | 166 | success: |
1da177e4 | 167 | /* |
c1e8d7c6 | 168 | * vm_flags is protected by the mmap_lock held in write mode. |
1da177e4 | 169 | */ |
e798c6e8 | 170 | vma->vm_flags = new_flags; |
f3bc0dba MR |
171 | |
172 | out_convert_errno: | |
173 | /* | |
174 | * madvise() returns EAGAIN if kernel resources, such as | |
175 | * slab, are temporarily unavailable. | |
176 | */ | |
177 | if (error == -ENOMEM) | |
178 | error = -EAGAIN; | |
1da177e4 | 179 | out: |
1da177e4 LT |
180 | return error; |
181 | } | |
182 | ||
1998cc04 SL |
183 | #ifdef CONFIG_SWAP |
184 | static int swapin_walk_pmd_entry(pmd_t *pmd, unsigned long start, | |
185 | unsigned long end, struct mm_walk *walk) | |
186 | { | |
187 | pte_t *orig_pte; | |
188 | struct vm_area_struct *vma = walk->private; | |
189 | unsigned long index; | |
190 | ||
191 | if (pmd_none_or_trans_huge_or_clear_bad(pmd)) | |
192 | return 0; | |
193 | ||
194 | for (index = start; index != end; index += PAGE_SIZE) { | |
195 | pte_t pte; | |
196 | swp_entry_t entry; | |
197 | struct page *page; | |
198 | spinlock_t *ptl; | |
199 | ||
200 | orig_pte = pte_offset_map_lock(vma->vm_mm, pmd, start, &ptl); | |
201 | pte = *(orig_pte + ((index - start) / PAGE_SIZE)); | |
202 | pte_unmap_unlock(orig_pte, ptl); | |
203 | ||
0661a336 | 204 | if (pte_present(pte) || pte_none(pte)) |
1998cc04 SL |
205 | continue; |
206 | entry = pte_to_swp_entry(pte); | |
207 | if (unlikely(non_swap_entry(entry))) | |
208 | continue; | |
209 | ||
210 | page = read_swap_cache_async(entry, GFP_HIGHUSER_MOVABLE, | |
23955622 | 211 | vma, index, false); |
1998cc04 | 212 | if (page) |
09cbfeaf | 213 | put_page(page); |
1998cc04 SL |
214 | } |
215 | ||
216 | return 0; | |
217 | } | |
218 | ||
7b86ac33 CH |
219 | static const struct mm_walk_ops swapin_walk_ops = { |
220 | .pmd_entry = swapin_walk_pmd_entry, | |
221 | }; | |
1998cc04 SL |
222 | |
223 | static void force_shm_swapin_readahead(struct vm_area_struct *vma, | |
224 | unsigned long start, unsigned long end, | |
225 | struct address_space *mapping) | |
226 | { | |
e6e88712 MWO |
227 | XA_STATE(xas, &mapping->i_pages, linear_page_index(vma, start)); |
228 | pgoff_t end_index = end / PAGE_SIZE; | |
1998cc04 | 229 | struct page *page; |
1998cc04 | 230 | |
e6e88712 MWO |
231 | rcu_read_lock(); |
232 | xas_for_each(&xas, page, end_index) { | |
233 | swp_entry_t swap; | |
1998cc04 | 234 | |
e6e88712 | 235 | if (!xa_is_value(page)) |
1998cc04 | 236 | continue; |
e6e88712 MWO |
237 | xas_pause(&xas); |
238 | rcu_read_unlock(); | |
239 | ||
1998cc04 SL |
240 | swap = radix_to_swp_entry(page); |
241 | page = read_swap_cache_async(swap, GFP_HIGHUSER_MOVABLE, | |
23955622 | 242 | NULL, 0, false); |
1998cc04 | 243 | if (page) |
09cbfeaf | 244 | put_page(page); |
e6e88712 MWO |
245 | |
246 | rcu_read_lock(); | |
1998cc04 | 247 | } |
e6e88712 | 248 | rcu_read_unlock(); |
1998cc04 SL |
249 | |
250 | lru_add_drain(); /* Push any new pages onto the LRU now */ | |
251 | } | |
252 | #endif /* CONFIG_SWAP */ | |
253 | ||
1da177e4 LT |
254 | /* |
255 | * Schedule all required I/O operations. Do not wait for completion. | |
256 | */ | |
ec9bed9d VC |
257 | static long madvise_willneed(struct vm_area_struct *vma, |
258 | struct vm_area_struct **prev, | |
1da177e4 LT |
259 | unsigned long start, unsigned long end) |
260 | { | |
261 | struct file *file = vma->vm_file; | |
692fe624 | 262 | loff_t offset; |
1da177e4 | 263 | |
6ea8d958 | 264 | *prev = vma; |
1998cc04 | 265 | #ifdef CONFIG_SWAP |
97b713ba | 266 | if (!file) { |
7b86ac33 CH |
267 | walk_page_range(vma->vm_mm, start, end, &swapin_walk_ops, vma); |
268 | lru_add_drain(); /* Push any new pages onto the LRU now */ | |
1998cc04 SL |
269 | return 0; |
270 | } | |
1998cc04 | 271 | |
97b713ba | 272 | if (shmem_mapping(file->f_mapping)) { |
97b713ba CH |
273 | force_shm_swapin_readahead(vma, start, end, |
274 | file->f_mapping); | |
275 | return 0; | |
276 | } | |
277 | #else | |
1bef4003 S |
278 | if (!file) |
279 | return -EBADF; | |
97b713ba | 280 | #endif |
1bef4003 | 281 | |
e748dcd0 | 282 | if (IS_DAX(file_inode(file))) { |
fe77ba6f CO |
283 | /* no bad return value, but ignore advice */ |
284 | return 0; | |
285 | } | |
286 | ||
692fe624 JK |
287 | /* |
288 | * Filesystem's fadvise may need to take various locks. We need to | |
289 | * explicitly grab a reference because the vma (and hence the | |
290 | * vma's reference to the file) can go away as soon as we drop | |
c1e8d7c6 | 291 | * mmap_lock. |
692fe624 | 292 | */ |
c1e8d7c6 | 293 | *prev = NULL; /* tell sys_madvise we drop mmap_lock */ |
692fe624 | 294 | get_file(file); |
692fe624 JK |
295 | offset = (loff_t)(start - vma->vm_start) |
296 | + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); | |
7867fd7c | 297 | mmap_read_unlock(current->mm); |
692fe624 JK |
298 | vfs_fadvise(file, offset, end - start, POSIX_FADV_WILLNEED); |
299 | fput(file); | |
d8ed45c5 | 300 | mmap_read_lock(current->mm); |
1da177e4 LT |
301 | return 0; |
302 | } | |
303 | ||
d616d512 MK |
304 | static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, |
305 | unsigned long addr, unsigned long end, | |
306 | struct mm_walk *walk) | |
9c276cc6 | 307 | { |
d616d512 MK |
308 | struct madvise_walk_private *private = walk->private; |
309 | struct mmu_gather *tlb = private->tlb; | |
310 | bool pageout = private->pageout; | |
9c276cc6 MK |
311 | struct mm_struct *mm = tlb->mm; |
312 | struct vm_area_struct *vma = walk->vma; | |
313 | pte_t *orig_pte, *pte, ptent; | |
314 | spinlock_t *ptl; | |
d616d512 MK |
315 | struct page *page = NULL; |
316 | LIST_HEAD(page_list); | |
317 | ||
318 | if (fatal_signal_pending(current)) | |
319 | return -EINTR; | |
9c276cc6 MK |
320 | |
321 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE | |
322 | if (pmd_trans_huge(*pmd)) { | |
323 | pmd_t orig_pmd; | |
324 | unsigned long next = pmd_addr_end(addr, end); | |
325 | ||
326 | tlb_change_page_size(tlb, HPAGE_PMD_SIZE); | |
327 | ptl = pmd_trans_huge_lock(pmd, vma); | |
328 | if (!ptl) | |
329 | return 0; | |
330 | ||
331 | orig_pmd = *pmd; | |
332 | if (is_huge_zero_pmd(orig_pmd)) | |
333 | goto huge_unlock; | |
334 | ||
335 | if (unlikely(!pmd_present(orig_pmd))) { | |
336 | VM_BUG_ON(thp_migration_supported() && | |
337 | !is_pmd_migration_entry(orig_pmd)); | |
338 | goto huge_unlock; | |
339 | } | |
340 | ||
341 | page = pmd_page(orig_pmd); | |
12e967fd MH |
342 | |
343 | /* Do not interfere with other mappings of this page */ | |
344 | if (page_mapcount(page) != 1) | |
345 | goto huge_unlock; | |
346 | ||
9c276cc6 MK |
347 | if (next - addr != HPAGE_PMD_SIZE) { |
348 | int err; | |
349 | ||
9c276cc6 MK |
350 | get_page(page); |
351 | spin_unlock(ptl); | |
352 | lock_page(page); | |
353 | err = split_huge_page(page); | |
354 | unlock_page(page); | |
355 | put_page(page); | |
356 | if (!err) | |
357 | goto regular_page; | |
358 | return 0; | |
359 | } | |
360 | ||
361 | if (pmd_young(orig_pmd)) { | |
362 | pmdp_invalidate(vma, addr, pmd); | |
363 | orig_pmd = pmd_mkold(orig_pmd); | |
364 | ||
365 | set_pmd_at(mm, addr, pmd, orig_pmd); | |
366 | tlb_remove_pmd_tlb_entry(tlb, pmd, addr); | |
367 | } | |
368 | ||
d616d512 | 369 | ClearPageReferenced(page); |
9c276cc6 | 370 | test_and_clear_page_young(page); |
d616d512 | 371 | if (pageout) { |
82072962 | 372 | if (!isolate_lru_page(page)) { |
373 | if (PageUnevictable(page)) | |
374 | putback_lru_page(page); | |
375 | else | |
376 | list_add(&page->lru, &page_list); | |
377 | } | |
d616d512 MK |
378 | } else |
379 | deactivate_page(page); | |
9c276cc6 MK |
380 | huge_unlock: |
381 | spin_unlock(ptl); | |
d616d512 MK |
382 | if (pageout) |
383 | reclaim_pages(&page_list); | |
9c276cc6 MK |
384 | return 0; |
385 | } | |
386 | ||
ce268425 | 387 | regular_page: |
9c276cc6 MK |
388 | if (pmd_trans_unstable(pmd)) |
389 | return 0; | |
9c276cc6 MK |
390 | #endif |
391 | tlb_change_page_size(tlb, PAGE_SIZE); | |
392 | orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
393 | flush_tlb_batched_pending(mm); | |
394 | arch_enter_lazy_mmu_mode(); | |
395 | for (; addr < end; pte++, addr += PAGE_SIZE) { | |
396 | ptent = *pte; | |
397 | ||
398 | if (pte_none(ptent)) | |
399 | continue; | |
400 | ||
401 | if (!pte_present(ptent)) | |
402 | continue; | |
403 | ||
404 | page = vm_normal_page(vma, addr, ptent); | |
405 | if (!page) | |
406 | continue; | |
407 | ||
408 | /* | |
409 | * Creating a THP page is expensive so split it only if we | |
410 | * are sure it's worth. Split it if we are only owner. | |
411 | */ | |
412 | if (PageTransCompound(page)) { | |
413 | if (page_mapcount(page) != 1) | |
414 | break; | |
415 | get_page(page); | |
416 | if (!trylock_page(page)) { | |
417 | put_page(page); | |
418 | break; | |
419 | } | |
420 | pte_unmap_unlock(orig_pte, ptl); | |
421 | if (split_huge_page(page)) { | |
422 | unlock_page(page); | |
423 | put_page(page); | |
424 | pte_offset_map_lock(mm, pmd, addr, &ptl); | |
425 | break; | |
426 | } | |
427 | unlock_page(page); | |
428 | put_page(page); | |
429 | pte = pte_offset_map_lock(mm, pmd, addr, &ptl); | |
430 | pte--; | |
431 | addr -= PAGE_SIZE; | |
432 | continue; | |
433 | } | |
434 | ||
12e967fd MH |
435 | /* Do not interfere with other mappings of this page */ |
436 | if (page_mapcount(page) != 1) | |
437 | continue; | |
438 | ||
9c276cc6 MK |
439 | VM_BUG_ON_PAGE(PageTransCompound(page), page); |
440 | ||
441 | if (pte_young(ptent)) { | |
442 | ptent = ptep_get_and_clear_full(mm, addr, pte, | |
443 | tlb->fullmm); | |
444 | ptent = pte_mkold(ptent); | |
445 | set_pte_at(mm, addr, pte, ptent); | |
446 | tlb_remove_tlb_entry(tlb, pte, addr); | |
447 | } | |
448 | ||
449 | /* | |
450 | * We are deactivating a page for accelerating reclaiming. | |
451 | * VM couldn't reclaim the page unless we clear PG_young. | |
452 | * As a side effect, it makes confuse idle-page tracking | |
453 | * because they will miss recent referenced history. | |
454 | */ | |
d616d512 | 455 | ClearPageReferenced(page); |
9c276cc6 | 456 | test_and_clear_page_young(page); |
d616d512 | 457 | if (pageout) { |
82072962 | 458 | if (!isolate_lru_page(page)) { |
459 | if (PageUnevictable(page)) | |
460 | putback_lru_page(page); | |
461 | else | |
462 | list_add(&page->lru, &page_list); | |
463 | } | |
d616d512 MK |
464 | } else |
465 | deactivate_page(page); | |
9c276cc6 MK |
466 | } |
467 | ||
468 | arch_leave_lazy_mmu_mode(); | |
469 | pte_unmap_unlock(orig_pte, ptl); | |
d616d512 MK |
470 | if (pageout) |
471 | reclaim_pages(&page_list); | |
9c276cc6 MK |
472 | cond_resched(); |
473 | ||
474 | return 0; | |
475 | } | |
476 | ||
477 | static const struct mm_walk_ops cold_walk_ops = { | |
d616d512 | 478 | .pmd_entry = madvise_cold_or_pageout_pte_range, |
9c276cc6 MK |
479 | }; |
480 | ||
481 | static void madvise_cold_page_range(struct mmu_gather *tlb, | |
482 | struct vm_area_struct *vma, | |
483 | unsigned long addr, unsigned long end) | |
484 | { | |
d616d512 MK |
485 | struct madvise_walk_private walk_private = { |
486 | .pageout = false, | |
487 | .tlb = tlb, | |
488 | }; | |
489 | ||
9c276cc6 | 490 | tlb_start_vma(tlb, vma); |
d616d512 | 491 | walk_page_range(vma->vm_mm, addr, end, &cold_walk_ops, &walk_private); |
9c276cc6 MK |
492 | tlb_end_vma(tlb, vma); |
493 | } | |
494 | ||
495 | static long madvise_cold(struct vm_area_struct *vma, | |
496 | struct vm_area_struct **prev, | |
497 | unsigned long start_addr, unsigned long end_addr) | |
498 | { | |
499 | struct mm_struct *mm = vma->vm_mm; | |
500 | struct mmu_gather tlb; | |
501 | ||
502 | *prev = vma; | |
503 | if (!can_madv_lru_vma(vma)) | |
504 | return -EINVAL; | |
505 | ||
506 | lru_add_drain(); | |
507 | tlb_gather_mmu(&tlb, mm, start_addr, end_addr); | |
508 | madvise_cold_page_range(&tlb, vma, start_addr, end_addr); | |
509 | tlb_finish_mmu(&tlb, start_addr, end_addr); | |
510 | ||
511 | return 0; | |
512 | } | |
513 | ||
1a4e58cc MK |
514 | static void madvise_pageout_page_range(struct mmu_gather *tlb, |
515 | struct vm_area_struct *vma, | |
516 | unsigned long addr, unsigned long end) | |
517 | { | |
d616d512 MK |
518 | struct madvise_walk_private walk_private = { |
519 | .pageout = true, | |
520 | .tlb = tlb, | |
521 | }; | |
522 | ||
1a4e58cc | 523 | tlb_start_vma(tlb, vma); |
d616d512 | 524 | walk_page_range(vma->vm_mm, addr, end, &cold_walk_ops, &walk_private); |
1a4e58cc MK |
525 | tlb_end_vma(tlb, vma); |
526 | } | |
527 | ||
528 | static inline bool can_do_pageout(struct vm_area_struct *vma) | |
529 | { | |
530 | if (vma_is_anonymous(vma)) | |
531 | return true; | |
532 | if (!vma->vm_file) | |
533 | return false; | |
534 | /* | |
535 | * paging out pagecache only for non-anonymous mappings that correspond | |
536 | * to the files the calling process could (if tried) open for writing; | |
537 | * otherwise we'd be including shared non-exclusive mappings, which | |
538 | * opens a side channel. | |
539 | */ | |
540 | return inode_owner_or_capable(file_inode(vma->vm_file)) || | |
541 | inode_permission(file_inode(vma->vm_file), MAY_WRITE) == 0; | |
542 | } | |
543 | ||
544 | static long madvise_pageout(struct vm_area_struct *vma, | |
545 | struct vm_area_struct **prev, | |
546 | unsigned long start_addr, unsigned long end_addr) | |
547 | { | |
548 | struct mm_struct *mm = vma->vm_mm; | |
549 | struct mmu_gather tlb; | |
550 | ||
551 | *prev = vma; | |
552 | if (!can_madv_lru_vma(vma)) | |
553 | return -EINVAL; | |
554 | ||
555 | if (!can_do_pageout(vma)) | |
556 | return 0; | |
557 | ||
558 | lru_add_drain(); | |
559 | tlb_gather_mmu(&tlb, mm, start_addr, end_addr); | |
560 | madvise_pageout_page_range(&tlb, vma, start_addr, end_addr); | |
561 | tlb_finish_mmu(&tlb, start_addr, end_addr); | |
562 | ||
563 | return 0; | |
564 | } | |
565 | ||
854e9ed0 MK |
566 | static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr, |
567 | unsigned long end, struct mm_walk *walk) | |
568 | ||
569 | { | |
570 | struct mmu_gather *tlb = walk->private; | |
571 | struct mm_struct *mm = tlb->mm; | |
572 | struct vm_area_struct *vma = walk->vma; | |
573 | spinlock_t *ptl; | |
574 | pte_t *orig_pte, *pte, ptent; | |
575 | struct page *page; | |
64b42bc1 | 576 | int nr_swap = 0; |
b8d3c4c3 MK |
577 | unsigned long next; |
578 | ||
579 | next = pmd_addr_end(addr, end); | |
580 | if (pmd_trans_huge(*pmd)) | |
581 | if (madvise_free_huge_pmd(tlb, vma, pmd, addr, next)) | |
582 | goto next; | |
854e9ed0 | 583 | |
854e9ed0 MK |
584 | if (pmd_trans_unstable(pmd)) |
585 | return 0; | |
586 | ||
ed6a7935 | 587 | tlb_change_page_size(tlb, PAGE_SIZE); |
854e9ed0 | 588 | orig_pte = pte = pte_offset_map_lock(mm, pmd, addr, &ptl); |
3ea27719 | 589 | flush_tlb_batched_pending(mm); |
854e9ed0 MK |
590 | arch_enter_lazy_mmu_mode(); |
591 | for (; addr != end; pte++, addr += PAGE_SIZE) { | |
592 | ptent = *pte; | |
593 | ||
64b42bc1 | 594 | if (pte_none(ptent)) |
854e9ed0 | 595 | continue; |
64b42bc1 MK |
596 | /* |
597 | * If the pte has swp_entry, just clear page table to | |
598 | * prevent swap-in which is more expensive rather than | |
599 | * (page allocation + zeroing). | |
600 | */ | |
601 | if (!pte_present(ptent)) { | |
602 | swp_entry_t entry; | |
603 | ||
604 | entry = pte_to_swp_entry(ptent); | |
605 | if (non_swap_entry(entry)) | |
606 | continue; | |
607 | nr_swap--; | |
608 | free_swap_and_cache(entry); | |
609 | pte_clear_not_present_full(mm, addr, pte, tlb->fullmm); | |
610 | continue; | |
611 | } | |
854e9ed0 | 612 | |
25b2995a | 613 | page = vm_normal_page(vma, addr, ptent); |
854e9ed0 MK |
614 | if (!page) |
615 | continue; | |
616 | ||
617 | /* | |
618 | * If pmd isn't transhuge but the page is THP and | |
619 | * is owned by only this process, split it and | |
620 | * deactivate all pages. | |
621 | */ | |
622 | if (PageTransCompound(page)) { | |
623 | if (page_mapcount(page) != 1) | |
624 | goto out; | |
625 | get_page(page); | |
626 | if (!trylock_page(page)) { | |
627 | put_page(page); | |
628 | goto out; | |
629 | } | |
630 | pte_unmap_unlock(orig_pte, ptl); | |
631 | if (split_huge_page(page)) { | |
632 | unlock_page(page); | |
633 | put_page(page); | |
634 | pte_offset_map_lock(mm, pmd, addr, &ptl); | |
635 | goto out; | |
636 | } | |
854e9ed0 | 637 | unlock_page(page); |
263630e8 | 638 | put_page(page); |
854e9ed0 MK |
639 | pte = pte_offset_map_lock(mm, pmd, addr, &ptl); |
640 | pte--; | |
641 | addr -= PAGE_SIZE; | |
642 | continue; | |
643 | } | |
644 | ||
645 | VM_BUG_ON_PAGE(PageTransCompound(page), page); | |
646 | ||
647 | if (PageSwapCache(page) || PageDirty(page)) { | |
648 | if (!trylock_page(page)) | |
649 | continue; | |
650 | /* | |
651 | * If page is shared with others, we couldn't clear | |
652 | * PG_dirty of the page. | |
653 | */ | |
654 | if (page_mapcount(page) != 1) { | |
655 | unlock_page(page); | |
656 | continue; | |
657 | } | |
658 | ||
659 | if (PageSwapCache(page) && !try_to_free_swap(page)) { | |
660 | unlock_page(page); | |
661 | continue; | |
662 | } | |
663 | ||
664 | ClearPageDirty(page); | |
665 | unlock_page(page); | |
666 | } | |
667 | ||
668 | if (pte_young(ptent) || pte_dirty(ptent)) { | |
669 | /* | |
670 | * Some of architecture(ex, PPC) don't update TLB | |
671 | * with set_pte_at and tlb_remove_tlb_entry so for | |
672 | * the portability, remap the pte with old|clean | |
673 | * after pte clearing. | |
674 | */ | |
675 | ptent = ptep_get_and_clear_full(mm, addr, pte, | |
676 | tlb->fullmm); | |
677 | ||
678 | ptent = pte_mkold(ptent); | |
679 | ptent = pte_mkclean(ptent); | |
680 | set_pte_at(mm, addr, pte, ptent); | |
681 | tlb_remove_tlb_entry(tlb, pte, addr); | |
682 | } | |
802a3a92 | 683 | mark_page_lazyfree(page); |
854e9ed0 MK |
684 | } |
685 | out: | |
64b42bc1 MK |
686 | if (nr_swap) { |
687 | if (current->mm == mm) | |
688 | sync_mm_rss(mm); | |
689 | ||
690 | add_mm_counter(mm, MM_SWAPENTS, nr_swap); | |
691 | } | |
854e9ed0 MK |
692 | arch_leave_lazy_mmu_mode(); |
693 | pte_unmap_unlock(orig_pte, ptl); | |
694 | cond_resched(); | |
b8d3c4c3 | 695 | next: |
854e9ed0 MK |
696 | return 0; |
697 | } | |
698 | ||
7b86ac33 CH |
699 | static const struct mm_walk_ops madvise_free_walk_ops = { |
700 | .pmd_entry = madvise_free_pte_range, | |
701 | }; | |
854e9ed0 MK |
702 | |
703 | static int madvise_free_single_vma(struct vm_area_struct *vma, | |
704 | unsigned long start_addr, unsigned long end_addr) | |
705 | { | |
854e9ed0 | 706 | struct mm_struct *mm = vma->vm_mm; |
ac46d4f3 | 707 | struct mmu_notifier_range range; |
854e9ed0 MK |
708 | struct mmu_gather tlb; |
709 | ||
854e9ed0 MK |
710 | /* MADV_FREE works for only anon vma at the moment */ |
711 | if (!vma_is_anonymous(vma)) | |
712 | return -EINVAL; | |
713 | ||
ac46d4f3 JG |
714 | range.start = max(vma->vm_start, start_addr); |
715 | if (range.start >= vma->vm_end) | |
854e9ed0 | 716 | return -EINVAL; |
ac46d4f3 JG |
717 | range.end = min(vma->vm_end, end_addr); |
718 | if (range.end <= vma->vm_start) | |
854e9ed0 | 719 | return -EINVAL; |
7269f999 | 720 | mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, |
6f4f13e8 | 721 | range.start, range.end); |
854e9ed0 MK |
722 | |
723 | lru_add_drain(); | |
ac46d4f3 | 724 | tlb_gather_mmu(&tlb, mm, range.start, range.end); |
854e9ed0 MK |
725 | update_hiwater_rss(mm); |
726 | ||
ac46d4f3 | 727 | mmu_notifier_invalidate_range_start(&range); |
7b86ac33 CH |
728 | tlb_start_vma(&tlb, vma); |
729 | walk_page_range(vma->vm_mm, range.start, range.end, | |
730 | &madvise_free_walk_ops, &tlb); | |
731 | tlb_end_vma(&tlb, vma); | |
ac46d4f3 JG |
732 | mmu_notifier_invalidate_range_end(&range); |
733 | tlb_finish_mmu(&tlb, range.start, range.end); | |
854e9ed0 MK |
734 | |
735 | return 0; | |
736 | } | |
737 | ||
1da177e4 LT |
738 | /* |
739 | * Application no longer needs these pages. If the pages are dirty, | |
740 | * it's OK to just throw them away. The app will be more careful about | |
741 | * data it wants to keep. Be sure to free swap resources too. The | |
7e6cbea3 | 742 | * zap_page_range call sets things up for shrink_active_list to actually free |
1da177e4 LT |
743 | * these pages later if no one else has touched them in the meantime, |
744 | * although we could add these pages to a global reuse list for | |
7e6cbea3 | 745 | * shrink_active_list to pick up before reclaiming other pages. |
1da177e4 LT |
746 | * |
747 | * NB: This interface discards data rather than pushes it out to swap, | |
748 | * as some implementations do. This has performance implications for | |
749 | * applications like large transactional databases which want to discard | |
750 | * pages in anonymous maps after committing to backing store the data | |
751 | * that was kept in them. There is no reason to write this data out to | |
752 | * the swap area if the application is discarding it. | |
753 | * | |
754 | * An interface that causes the system to free clean pages and flush | |
755 | * dirty pages is already available as msync(MS_INVALIDATE). | |
756 | */ | |
230ca982 MR |
757 | static long madvise_dontneed_single_vma(struct vm_area_struct *vma, |
758 | unsigned long start, unsigned long end) | |
759 | { | |
760 | zap_page_range(vma, start, end - start); | |
761 | return 0; | |
762 | } | |
763 | ||
764 | static long madvise_dontneed_free(struct vm_area_struct *vma, | |
765 | struct vm_area_struct **prev, | |
766 | unsigned long start, unsigned long end, | |
767 | int behavior) | |
1da177e4 | 768 | { |
05b74384 | 769 | *prev = vma; |
9c276cc6 | 770 | if (!can_madv_lru_vma(vma)) |
1da177e4 LT |
771 | return -EINVAL; |
772 | ||
70ccb92f | 773 | if (!userfaultfd_remove(vma, start, end)) { |
c1e8d7c6 | 774 | *prev = NULL; /* mmap_lock has been dropped, prev is stale */ |
70ccb92f | 775 | |
d8ed45c5 | 776 | mmap_read_lock(current->mm); |
70ccb92f AA |
777 | vma = find_vma(current->mm, start); |
778 | if (!vma) | |
779 | return -ENOMEM; | |
780 | if (start < vma->vm_start) { | |
781 | /* | |
782 | * This "vma" under revalidation is the one | |
783 | * with the lowest vma->vm_start where start | |
784 | * is also < vma->vm_end. If start < | |
785 | * vma->vm_start it means an hole materialized | |
786 | * in the user address space within the | |
230ca982 MR |
787 | * virtual range passed to MADV_DONTNEED |
788 | * or MADV_FREE. | |
70ccb92f AA |
789 | */ |
790 | return -ENOMEM; | |
791 | } | |
9c276cc6 | 792 | if (!can_madv_lru_vma(vma)) |
70ccb92f AA |
793 | return -EINVAL; |
794 | if (end > vma->vm_end) { | |
795 | /* | |
796 | * Don't fail if end > vma->vm_end. If the old | |
c1e8d7c6 | 797 | * vma was splitted while the mmap_lock was |
70ccb92f | 798 | * released the effect of the concurrent |
230ca982 | 799 | * operation may not cause madvise() to |
70ccb92f AA |
800 | * have an undefined result. There may be an |
801 | * adjacent next vma that we'll walk | |
802 | * next. userfaultfd_remove() will generate an | |
803 | * UFFD_EVENT_REMOVE repetition on the | |
804 | * end-vma->vm_end range, but the manager can | |
805 | * handle a repetition fine. | |
806 | */ | |
807 | end = vma->vm_end; | |
808 | } | |
809 | VM_WARN_ON(start >= end); | |
810 | } | |
230ca982 MR |
811 | |
812 | if (behavior == MADV_DONTNEED) | |
813 | return madvise_dontneed_single_vma(vma, start, end); | |
814 | else if (behavior == MADV_FREE) | |
815 | return madvise_free_single_vma(vma, start, end); | |
816 | else | |
817 | return -EINVAL; | |
1da177e4 LT |
818 | } |
819 | ||
f6b3ec23 BP |
820 | /* |
821 | * Application wants to free up the pages and associated backing store. | |
822 | * This is effectively punching a hole into the middle of a file. | |
f6b3ec23 BP |
823 | */ |
824 | static long madvise_remove(struct vm_area_struct *vma, | |
00e9fa2d | 825 | struct vm_area_struct **prev, |
f6b3ec23 BP |
826 | unsigned long start, unsigned long end) |
827 | { | |
3f31d075 | 828 | loff_t offset; |
90ed52eb | 829 | int error; |
9ab4233d | 830 | struct file *f; |
f6b3ec23 | 831 | |
c1e8d7c6 | 832 | *prev = NULL; /* tell sys_madvise we drop mmap_lock */ |
00e9fa2d | 833 | |
72079ba0 | 834 | if (vma->vm_flags & VM_LOCKED) |
f6b3ec23 BP |
835 | return -EINVAL; |
836 | ||
9ab4233d AL |
837 | f = vma->vm_file; |
838 | ||
839 | if (!f || !f->f_mapping || !f->f_mapping->host) { | |
f6b3ec23 BP |
840 | return -EINVAL; |
841 | } | |
842 | ||
69cf0fac HD |
843 | if ((vma->vm_flags & (VM_SHARED|VM_WRITE)) != (VM_SHARED|VM_WRITE)) |
844 | return -EACCES; | |
845 | ||
f6b3ec23 BP |
846 | offset = (loff_t)(start - vma->vm_start) |
847 | + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); | |
90ed52eb | 848 | |
9ab4233d AL |
849 | /* |
850 | * Filesystem's fallocate may need to take i_mutex. We need to | |
851 | * explicitly grab a reference because the vma (and hence the | |
852 | * vma's reference to the file) can go away as soon as we drop | |
c1e8d7c6 | 853 | * mmap_lock. |
9ab4233d AL |
854 | */ |
855 | get_file(f); | |
70ccb92f | 856 | if (userfaultfd_remove(vma, start, end)) { |
c1e8d7c6 | 857 | /* mmap_lock was not released by userfaultfd_remove() */ |
d8ed45c5 | 858 | mmap_read_unlock(current->mm); |
70ccb92f | 859 | } |
72c72bdf | 860 | error = vfs_fallocate(f, |
3f31d075 HD |
861 | FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, |
862 | offset, end - start); | |
9ab4233d | 863 | fput(f); |
d8ed45c5 | 864 | mmap_read_lock(current->mm); |
90ed52eb | 865 | return error; |
f6b3ec23 BP |
866 | } |
867 | ||
9893e49d AK |
868 | #ifdef CONFIG_MEMORY_FAILURE |
869 | /* | |
870 | * Error injection support for memory error handling. | |
871 | */ | |
97167a76 AK |
872 | static int madvise_inject_error(int behavior, |
873 | unsigned long start, unsigned long end) | |
9893e49d | 874 | { |
97167a76 | 875 | struct page *page; |
c461ad6a | 876 | struct zone *zone; |
d3cd257c | 877 | unsigned long size; |
97167a76 | 878 | |
9893e49d AK |
879 | if (!capable(CAP_SYS_ADMIN)) |
880 | return -EPERM; | |
97167a76 | 881 | |
19bfbe22 | 882 | |
d3cd257c | 883 | for (; start < end; start += size) { |
23e7b5c2 | 884 | unsigned long pfn; |
325c4ef5 AM |
885 | int ret; |
886 | ||
97167a76 | 887 | ret = get_user_pages_fast(start, 1, 0, &page); |
9893e49d AK |
888 | if (ret != 1) |
889 | return ret; | |
23e7b5c2 | 890 | pfn = page_to_pfn(page); |
325c4ef5 | 891 | |
19bfbe22 AM |
892 | /* |
893 | * When soft offlining hugepages, after migrating the page | |
894 | * we dissolve it, therefore in the second loop "page" will | |
d3cd257c | 895 | * no longer be a compound page. |
19bfbe22 | 896 | */ |
d3cd257c | 897 | size = page_size(compound_head(page)); |
19bfbe22 | 898 | |
97167a76 AK |
899 | if (PageHWPoison(page)) { |
900 | put_page(page); | |
29b4eede WL |
901 | continue; |
902 | } | |
97167a76 AK |
903 | |
904 | if (behavior == MADV_SOFT_OFFLINE) { | |
905 | pr_info("Soft offlining pfn %#lx at process virtual address %#lx\n", | |
23e7b5c2 | 906 | pfn, start); |
97167a76 | 907 | |
feec24a6 | 908 | ret = soft_offline_page(pfn, MF_COUNT_INCREASED); |
afcf938e | 909 | if (ret) |
8302423b | 910 | return ret; |
afcf938e AK |
911 | continue; |
912 | } | |
23e7b5c2 | 913 | |
97167a76 | 914 | pr_info("Injecting memory failure for pfn %#lx at process virtual address %#lx\n", |
23e7b5c2 | 915 | pfn, start); |
97167a76 | 916 | |
23e7b5c2 DW |
917 | /* |
918 | * Drop the page reference taken by get_user_pages_fast(). In | |
919 | * the absence of MF_COUNT_INCREASED the memory_failure() | |
920 | * routine is responsible for pinning the page to prevent it | |
921 | * from being released back to the page allocator. | |
922 | */ | |
923 | put_page(page); | |
924 | ret = memory_failure(pfn, 0); | |
23a003bf NH |
925 | if (ret) |
926 | return ret; | |
9893e49d | 927 | } |
c461ad6a MG |
928 | |
929 | /* Ensure that all poisoned pages are removed from per-cpu lists */ | |
930 | for_each_populated_zone(zone) | |
931 | drain_all_pages(zone); | |
932 | ||
325c4ef5 | 933 | return 0; |
9893e49d AK |
934 | } |
935 | #endif | |
936 | ||
165cd402 | 937 | static long |
938 | madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev, | |
939 | unsigned long start, unsigned long end, int behavior) | |
1da177e4 | 940 | { |
1da177e4 | 941 | switch (behavior) { |
f6b3ec23 | 942 | case MADV_REMOVE: |
3866ea90 | 943 | return madvise_remove(vma, prev, start, end); |
1da177e4 | 944 | case MADV_WILLNEED: |
3866ea90 | 945 | return madvise_willneed(vma, prev, start, end); |
9c276cc6 MK |
946 | case MADV_COLD: |
947 | return madvise_cold(vma, prev, start, end); | |
1a4e58cc MK |
948 | case MADV_PAGEOUT: |
949 | return madvise_pageout(vma, prev, start, end); | |
854e9ed0 | 950 | case MADV_FREE: |
1da177e4 | 951 | case MADV_DONTNEED: |
230ca982 | 952 | return madvise_dontneed_free(vma, prev, start, end, behavior); |
1da177e4 | 953 | default: |
3866ea90 | 954 | return madvise_behavior(vma, prev, start, end, behavior); |
1da177e4 | 955 | } |
1da177e4 LT |
956 | } |
957 | ||
1ecef9ed | 958 | static bool |
75927af8 NP |
959 | madvise_behavior_valid(int behavior) |
960 | { | |
961 | switch (behavior) { | |
962 | case MADV_DOFORK: | |
963 | case MADV_DONTFORK: | |
964 | case MADV_NORMAL: | |
965 | case MADV_SEQUENTIAL: | |
966 | case MADV_RANDOM: | |
967 | case MADV_REMOVE: | |
968 | case MADV_WILLNEED: | |
969 | case MADV_DONTNEED: | |
854e9ed0 | 970 | case MADV_FREE: |
9c276cc6 | 971 | case MADV_COLD: |
1a4e58cc | 972 | case MADV_PAGEOUT: |
f8af4da3 HD |
973 | #ifdef CONFIG_KSM |
974 | case MADV_MERGEABLE: | |
975 | case MADV_UNMERGEABLE: | |
0af4e98b AA |
976 | #endif |
977 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE | |
978 | case MADV_HUGEPAGE: | |
a664b2d8 | 979 | case MADV_NOHUGEPAGE: |
f8af4da3 | 980 | #endif |
accb61fe JB |
981 | case MADV_DONTDUMP: |
982 | case MADV_DODUMP: | |
d2cd9ede RR |
983 | case MADV_WIPEONFORK: |
984 | case MADV_KEEPONFORK: | |
5e451be7 AK |
985 | #ifdef CONFIG_MEMORY_FAILURE |
986 | case MADV_SOFT_OFFLINE: | |
987 | case MADV_HWPOISON: | |
988 | #endif | |
1ecef9ed | 989 | return true; |
75927af8 NP |
990 | |
991 | default: | |
1ecef9ed | 992 | return false; |
75927af8 NP |
993 | } |
994 | } | |
3866ea90 | 995 | |
1da177e4 LT |
996 | /* |
997 | * The madvise(2) system call. | |
998 | * | |
999 | * Applications can use madvise() to advise the kernel how it should | |
1000 | * handle paging I/O in this VM area. The idea is to help the kernel | |
1001 | * use appropriate read-ahead and caching techniques. The information | |
1002 | * provided is advisory only, and can be safely disregarded by the | |
1003 | * kernel without affecting the correct operation of the application. | |
1004 | * | |
1005 | * behavior values: | |
1006 | * MADV_NORMAL - the default behavior is to read clusters. This | |
1007 | * results in some read-ahead and read-behind. | |
1008 | * MADV_RANDOM - the system should read the minimum amount of data | |
1009 | * on any access, since it is unlikely that the appli- | |
1010 | * cation will need more than what it asks for. | |
1011 | * MADV_SEQUENTIAL - pages in the given range will probably be accessed | |
1012 | * once, so they can be aggressively read ahead, and | |
1013 | * can be freed soon after they are accessed. | |
1014 | * MADV_WILLNEED - the application is notifying the system to read | |
1015 | * some pages ahead. | |
1016 | * MADV_DONTNEED - the application is finished with the given range, | |
1017 | * so the kernel can free resources associated with it. | |
d7206a70 NH |
1018 | * MADV_FREE - the application marks pages in the given range as lazy free, |
1019 | * where actual purges are postponed until memory pressure happens. | |
f6b3ec23 BP |
1020 | * MADV_REMOVE - the application wants to free up the given range of |
1021 | * pages and associated backing store. | |
3866ea90 HD |
1022 | * MADV_DONTFORK - omit this area from child's address space when forking: |
1023 | * typically, to avoid COWing pages pinned by get_user_pages(). | |
1024 | * MADV_DOFORK - cancel MADV_DONTFORK: no longer omit this area when forking. | |
c02c3009 YS |
1025 | * MADV_WIPEONFORK - present the child process with zero-filled memory in this |
1026 | * range after a fork. | |
1027 | * MADV_KEEPONFORK - undo the effect of MADV_WIPEONFORK | |
d7206a70 NH |
1028 | * MADV_HWPOISON - trigger memory error handler as if the given memory range |
1029 | * were corrupted by unrecoverable hardware memory failure. | |
1030 | * MADV_SOFT_OFFLINE - try to soft-offline the given range of memory. | |
f8af4da3 HD |
1031 | * MADV_MERGEABLE - the application recommends that KSM try to merge pages in |
1032 | * this area with pages of identical content from other such areas. | |
1033 | * MADV_UNMERGEABLE- cancel MADV_MERGEABLE: no longer merge pages with others. | |
d7206a70 NH |
1034 | * MADV_HUGEPAGE - the application wants to back the given range by transparent |
1035 | * huge pages in the future. Existing pages might be coalesced and | |
1036 | * new pages might be allocated as THP. | |
1037 | * MADV_NOHUGEPAGE - mark the given range as not worth being backed by | |
1038 | * transparent huge pages so the existing pages will not be | |
1039 | * coalesced into THP and new pages will not be allocated as THP. | |
1040 | * MADV_DONTDUMP - the application wants to prevent pages in the given range | |
1041 | * from being included in its core dump. | |
1042 | * MADV_DODUMP - cancel MADV_DONTDUMP: no longer exclude from core dump. | |
1da177e4 LT |
1043 | * |
1044 | * return values: | |
1045 | * zero - success | |
1046 | * -EINVAL - start + len < 0, start is not page-aligned, | |
1047 | * "behavior" is not a valid value, or application | |
c02c3009 YS |
1048 | * is attempting to release locked or shared pages, |
1049 | * or the specified address range includes file, Huge TLB, | |
1050 | * MAP_SHARED or VMPFNMAP range. | |
1da177e4 LT |
1051 | * -ENOMEM - addresses in the specified range are not currently |
1052 | * mapped, or are outside the AS of the process. | |
1053 | * -EIO - an I/O error occurred while paging in data. | |
1054 | * -EBADF - map exists, but area maps something that isn't a file. | |
1055 | * -EAGAIN - a kernel resource was temporarily unavailable. | |
1056 | */ | |
db08ca25 | 1057 | int do_madvise(unsigned long start, size_t len_in, int behavior) |
1da177e4 | 1058 | { |
05b74384 | 1059 | unsigned long end, tmp; |
ec9bed9d | 1060 | struct vm_area_struct *vma, *prev; |
1da177e4 LT |
1061 | int unmapped_error = 0; |
1062 | int error = -EINVAL; | |
f7977793 | 1063 | int write; |
1da177e4 | 1064 | size_t len; |
1998cc04 | 1065 | struct blk_plug plug; |
1da177e4 | 1066 | |
057d3389 AK |
1067 | start = untagged_addr(start); |
1068 | ||
75927af8 NP |
1069 | if (!madvise_behavior_valid(behavior)) |
1070 | return error; | |
1071 | ||
df6c6500 | 1072 | if (!PAGE_ALIGNED(start)) |
84d96d89 | 1073 | return error; |
df6c6500 | 1074 | len = PAGE_ALIGN(len_in); |
1da177e4 LT |
1075 | |
1076 | /* Check to see whether len was rounded up from small -ve to zero */ | |
1077 | if (len_in && !len) | |
84d96d89 | 1078 | return error; |
1da177e4 LT |
1079 | |
1080 | end = start + len; | |
1081 | if (end < start) | |
84d96d89 | 1082 | return error; |
1da177e4 LT |
1083 | |
1084 | error = 0; | |
1085 | if (end == start) | |
84d96d89 RV |
1086 | return error; |
1087 | ||
5e451be7 AK |
1088 | #ifdef CONFIG_MEMORY_FAILURE |
1089 | if (behavior == MADV_HWPOISON || behavior == MADV_SOFT_OFFLINE) | |
1090 | return madvise_inject_error(behavior, start, start + len_in); | |
1091 | #endif | |
1092 | ||
84d96d89 | 1093 | write = madvise_need_mmap_write(behavior); |
dc0ef0df | 1094 | if (write) { |
d8ed45c5 | 1095 | if (mmap_write_lock_killable(current->mm)) |
dc0ef0df | 1096 | return -EINTR; |
bc0c4d1e LT |
1097 | |
1098 | /* | |
1099 | * We may have stolen the mm from another process | |
1100 | * that is undergoing core dumping. | |
1101 | * | |
1102 | * Right now that's io_ring, in the future it may | |
1103 | * be remote process management and not "current" | |
1104 | * at all. | |
1105 | * | |
1106 | * We need to fix core dumping to not do this, | |
1107 | * but for now we have the mmget_still_valid() | |
1108 | * model. | |
1109 | */ | |
1110 | if (!mmget_still_valid(current->mm)) { | |
d8ed45c5 | 1111 | mmap_write_unlock(current->mm); |
bc0c4d1e LT |
1112 | return -EINTR; |
1113 | } | |
dc0ef0df | 1114 | } else { |
d8ed45c5 | 1115 | mmap_read_lock(current->mm); |
dc0ef0df | 1116 | } |
1da177e4 LT |
1117 | |
1118 | /* | |
1119 | * If the interval [start,end) covers some unmapped address | |
1120 | * ranges, just ignore them, but return -ENOMEM at the end. | |
05b74384 | 1121 | * - different from the way of handling in mlock etc. |
1da177e4 | 1122 | */ |
05b74384 | 1123 | vma = find_vma_prev(current->mm, start, &prev); |
836d5ffd HD |
1124 | if (vma && start > vma->vm_start) |
1125 | prev = vma; | |
1126 | ||
1998cc04 | 1127 | blk_start_plug(&plug); |
1da177e4 LT |
1128 | for (;;) { |
1129 | /* Still start < end. */ | |
1130 | error = -ENOMEM; | |
1131 | if (!vma) | |
84d96d89 | 1132 | goto out; |
1da177e4 | 1133 | |
05b74384 | 1134 | /* Here start < (end|vma->vm_end). */ |
1da177e4 LT |
1135 | if (start < vma->vm_start) { |
1136 | unmapped_error = -ENOMEM; | |
1137 | start = vma->vm_start; | |
05b74384 | 1138 | if (start >= end) |
84d96d89 | 1139 | goto out; |
1da177e4 LT |
1140 | } |
1141 | ||
05b74384 PM |
1142 | /* Here vma->vm_start <= start < (end|vma->vm_end) */ |
1143 | tmp = vma->vm_end; | |
1144 | if (end < tmp) | |
1145 | tmp = end; | |
1da177e4 | 1146 | |
05b74384 PM |
1147 | /* Here vma->vm_start <= start < tmp <= (end|vma->vm_end). */ |
1148 | error = madvise_vma(vma, &prev, start, tmp, behavior); | |
1da177e4 | 1149 | if (error) |
84d96d89 | 1150 | goto out; |
05b74384 | 1151 | start = tmp; |
90ed52eb | 1152 | if (prev && start < prev->vm_end) |
05b74384 PM |
1153 | start = prev->vm_end; |
1154 | error = unmapped_error; | |
1155 | if (start >= end) | |
84d96d89 | 1156 | goto out; |
90ed52eb HD |
1157 | if (prev) |
1158 | vma = prev->vm_next; | |
c1e8d7c6 | 1159 | else /* madvise_remove dropped mmap_lock */ |
90ed52eb | 1160 | vma = find_vma(current->mm, start); |
1da177e4 | 1161 | } |
1da177e4 | 1162 | out: |
84d96d89 | 1163 | blk_finish_plug(&plug); |
f7977793 | 1164 | if (write) |
d8ed45c5 | 1165 | mmap_write_unlock(current->mm); |
0a27a14a | 1166 | else |
d8ed45c5 | 1167 | mmap_read_unlock(current->mm); |
0a27a14a | 1168 | |
1da177e4 LT |
1169 | return error; |
1170 | } | |
db08ca25 JA |
1171 | |
1172 | SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior) | |
1173 | { | |
1174 | return do_madvise(start, len_in, behavior); | |
1175 | } |