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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/mm/madvise.c | |
3 | * | |
4 | * Copyright (C) 1999 Linus Torvalds | |
5 | * Copyright (C) 2002 Christoph Hellwig | |
6 | */ | |
7 | ||
8 | #include <linux/mman.h> | |
9 | #include <linux/pagemap.h> | |
10 | #include <linux/syscalls.h> | |
05b74384 | 11 | #include <linux/mempolicy.h> |
afcf938e | 12 | #include <linux/page-isolation.h> |
1da177e4 | 13 | #include <linux/hugetlb.h> |
3f31d075 | 14 | #include <linux/falloc.h> |
e8edc6e0 | 15 | #include <linux/sched.h> |
f8af4da3 | 16 | #include <linux/ksm.h> |
3f31d075 | 17 | #include <linux/fs.h> |
9ab4233d | 18 | #include <linux/file.h> |
1998cc04 | 19 | #include <linux/blkdev.h> |
66114cad | 20 | #include <linux/backing-dev.h> |
1998cc04 SL |
21 | #include <linux/swap.h> |
22 | #include <linux/swapops.h> | |
854e9ed0 MK |
23 | #include <linux/mmu_notifier.h> |
24 | ||
25 | #include <asm/tlb.h> | |
1da177e4 | 26 | |
0a27a14a NP |
27 | /* |
28 | * Any behaviour which results in changes to the vma->vm_flags needs to | |
29 | * take mmap_sem for writing. Others, which simply traverse vmas, need | |
30 | * to only take it for reading. | |
31 | */ | |
32 | static int madvise_need_mmap_write(int behavior) | |
33 | { | |
34 | switch (behavior) { | |
35 | case MADV_REMOVE: | |
36 | case MADV_WILLNEED: | |
37 | case MADV_DONTNEED: | |
854e9ed0 | 38 | case MADV_FREE: |
0a27a14a NP |
39 | return 0; |
40 | default: | |
41 | /* be safe, default to 1. list exceptions explicitly */ | |
42 | return 1; | |
43 | } | |
44 | } | |
45 | ||
1da177e4 LT |
46 | /* |
47 | * We can potentially split a vm area into separate | |
48 | * areas, each area with its own behavior. | |
49 | */ | |
ec9bed9d | 50 | static long madvise_behavior(struct vm_area_struct *vma, |
05b74384 PM |
51 | struct vm_area_struct **prev, |
52 | unsigned long start, unsigned long end, int behavior) | |
1da177e4 | 53 | { |
ec9bed9d | 54 | struct mm_struct *mm = vma->vm_mm; |
1da177e4 | 55 | int error = 0; |
05b74384 | 56 | pgoff_t pgoff; |
3866ea90 | 57 | unsigned long new_flags = vma->vm_flags; |
e798c6e8 PM |
58 | |
59 | switch (behavior) { | |
f8225661 MT |
60 | case MADV_NORMAL: |
61 | new_flags = new_flags & ~VM_RAND_READ & ~VM_SEQ_READ; | |
62 | break; | |
e798c6e8 | 63 | case MADV_SEQUENTIAL: |
f8225661 | 64 | new_flags = (new_flags & ~VM_RAND_READ) | VM_SEQ_READ; |
e798c6e8 PM |
65 | break; |
66 | case MADV_RANDOM: | |
f8225661 | 67 | new_flags = (new_flags & ~VM_SEQ_READ) | VM_RAND_READ; |
e798c6e8 | 68 | break; |
f8225661 MT |
69 | case MADV_DONTFORK: |
70 | new_flags |= VM_DONTCOPY; | |
71 | break; | |
72 | case MADV_DOFORK: | |
3866ea90 HD |
73 | if (vma->vm_flags & VM_IO) { |
74 | error = -EINVAL; | |
75 | goto out; | |
76 | } | |
f8225661 | 77 | new_flags &= ~VM_DONTCOPY; |
e798c6e8 | 78 | break; |
accb61fe | 79 | case MADV_DONTDUMP: |
0103bd16 | 80 | new_flags |= VM_DONTDUMP; |
accb61fe JB |
81 | break; |
82 | case MADV_DODUMP: | |
0103bd16 KK |
83 | if (new_flags & VM_SPECIAL) { |
84 | error = -EINVAL; | |
85 | goto out; | |
86 | } | |
87 | new_flags &= ~VM_DONTDUMP; | |
accb61fe | 88 | break; |
f8af4da3 HD |
89 | case MADV_MERGEABLE: |
90 | case MADV_UNMERGEABLE: | |
91 | error = ksm_madvise(vma, start, end, behavior, &new_flags); | |
92 | if (error) | |
93 | goto out; | |
94 | break; | |
0af4e98b | 95 | case MADV_HUGEPAGE: |
a664b2d8 | 96 | case MADV_NOHUGEPAGE: |
60ab3244 | 97 | error = hugepage_madvise(vma, &new_flags, behavior); |
0af4e98b AA |
98 | if (error) |
99 | goto out; | |
100 | break; | |
e798c6e8 PM |
101 | } |
102 | ||
05b74384 PM |
103 | if (new_flags == vma->vm_flags) { |
104 | *prev = vma; | |
836d5ffd | 105 | goto out; |
05b74384 PM |
106 | } |
107 | ||
108 | pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); | |
109 | *prev = vma_merge(mm, *prev, start, end, new_flags, vma->anon_vma, | |
19a809af AA |
110 | vma->vm_file, pgoff, vma_policy(vma), |
111 | vma->vm_userfaultfd_ctx); | |
05b74384 PM |
112 | if (*prev) { |
113 | vma = *prev; | |
114 | goto success; | |
115 | } | |
116 | ||
117 | *prev = vma; | |
1da177e4 LT |
118 | |
119 | if (start != vma->vm_start) { | |
120 | error = split_vma(mm, vma, start, 1); | |
121 | if (error) | |
122 | goto out; | |
123 | } | |
124 | ||
125 | if (end != vma->vm_end) { | |
126 | error = split_vma(mm, vma, end, 0); | |
127 | if (error) | |
128 | goto out; | |
129 | } | |
130 | ||
836d5ffd | 131 | success: |
1da177e4 LT |
132 | /* |
133 | * vm_flags is protected by the mmap_sem held in write mode. | |
134 | */ | |
e798c6e8 | 135 | vma->vm_flags = new_flags; |
1da177e4 LT |
136 | |
137 | out: | |
138 | if (error == -ENOMEM) | |
139 | error = -EAGAIN; | |
140 | return error; | |
141 | } | |
142 | ||
1998cc04 SL |
143 | #ifdef CONFIG_SWAP |
144 | static int swapin_walk_pmd_entry(pmd_t *pmd, unsigned long start, | |
145 | unsigned long end, struct mm_walk *walk) | |
146 | { | |
147 | pte_t *orig_pte; | |
148 | struct vm_area_struct *vma = walk->private; | |
149 | unsigned long index; | |
150 | ||
151 | if (pmd_none_or_trans_huge_or_clear_bad(pmd)) | |
152 | return 0; | |
153 | ||
154 | for (index = start; index != end; index += PAGE_SIZE) { | |
155 | pte_t pte; | |
156 | swp_entry_t entry; | |
157 | struct page *page; | |
158 | spinlock_t *ptl; | |
159 | ||
160 | orig_pte = pte_offset_map_lock(vma->vm_mm, pmd, start, &ptl); | |
161 | pte = *(orig_pte + ((index - start) / PAGE_SIZE)); | |
162 | pte_unmap_unlock(orig_pte, ptl); | |
163 | ||
0661a336 | 164 | if (pte_present(pte) || pte_none(pte)) |
1998cc04 SL |
165 | continue; |
166 | entry = pte_to_swp_entry(pte); | |
167 | if (unlikely(non_swap_entry(entry))) | |
168 | continue; | |
169 | ||
170 | page = read_swap_cache_async(entry, GFP_HIGHUSER_MOVABLE, | |
171 | vma, index); | |
172 | if (page) | |
173 | page_cache_release(page); | |
174 | } | |
175 | ||
176 | return 0; | |
177 | } | |
178 | ||
179 | static void force_swapin_readahead(struct vm_area_struct *vma, | |
180 | unsigned long start, unsigned long end) | |
181 | { | |
182 | struct mm_walk walk = { | |
183 | .mm = vma->vm_mm, | |
184 | .pmd_entry = swapin_walk_pmd_entry, | |
185 | .private = vma, | |
186 | }; | |
187 | ||
188 | walk_page_range(start, end, &walk); | |
189 | ||
190 | lru_add_drain(); /* Push any new pages onto the LRU now */ | |
191 | } | |
192 | ||
193 | static void force_shm_swapin_readahead(struct vm_area_struct *vma, | |
194 | unsigned long start, unsigned long end, | |
195 | struct address_space *mapping) | |
196 | { | |
197 | pgoff_t index; | |
198 | struct page *page; | |
199 | swp_entry_t swap; | |
200 | ||
201 | for (; start < end; start += PAGE_SIZE) { | |
202 | index = ((start - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; | |
203 | ||
55231e5c | 204 | page = find_get_entry(mapping, index); |
1998cc04 SL |
205 | if (!radix_tree_exceptional_entry(page)) { |
206 | if (page) | |
207 | page_cache_release(page); | |
208 | continue; | |
209 | } | |
210 | swap = radix_to_swp_entry(page); | |
211 | page = read_swap_cache_async(swap, GFP_HIGHUSER_MOVABLE, | |
212 | NULL, 0); | |
213 | if (page) | |
214 | page_cache_release(page); | |
215 | } | |
216 | ||
217 | lru_add_drain(); /* Push any new pages onto the LRU now */ | |
218 | } | |
219 | #endif /* CONFIG_SWAP */ | |
220 | ||
1da177e4 LT |
221 | /* |
222 | * Schedule all required I/O operations. Do not wait for completion. | |
223 | */ | |
ec9bed9d VC |
224 | static long madvise_willneed(struct vm_area_struct *vma, |
225 | struct vm_area_struct **prev, | |
1da177e4 LT |
226 | unsigned long start, unsigned long end) |
227 | { | |
228 | struct file *file = vma->vm_file; | |
229 | ||
1998cc04 | 230 | #ifdef CONFIG_SWAP |
97b713ba | 231 | if (!file) { |
1998cc04 | 232 | *prev = vma; |
97b713ba | 233 | force_swapin_readahead(vma, start, end); |
1998cc04 SL |
234 | return 0; |
235 | } | |
1998cc04 | 236 | |
97b713ba CH |
237 | if (shmem_mapping(file->f_mapping)) { |
238 | *prev = vma; | |
239 | force_shm_swapin_readahead(vma, start, end, | |
240 | file->f_mapping); | |
241 | return 0; | |
242 | } | |
243 | #else | |
1bef4003 S |
244 | if (!file) |
245 | return -EBADF; | |
97b713ba | 246 | #endif |
1bef4003 | 247 | |
e748dcd0 | 248 | if (IS_DAX(file_inode(file))) { |
fe77ba6f CO |
249 | /* no bad return value, but ignore advice */ |
250 | return 0; | |
251 | } | |
252 | ||
05b74384 | 253 | *prev = vma; |
1da177e4 LT |
254 | start = ((start - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; |
255 | if (end > vma->vm_end) | |
256 | end = vma->vm_end; | |
257 | end = ((end - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; | |
258 | ||
f7e839dd | 259 | force_page_cache_readahead(file->f_mapping, file, start, end - start); |
1da177e4 LT |
260 | return 0; |
261 | } | |
262 | ||
854e9ed0 MK |
263 | static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr, |
264 | unsigned long end, struct mm_walk *walk) | |
265 | ||
266 | { | |
267 | struct mmu_gather *tlb = walk->private; | |
268 | struct mm_struct *mm = tlb->mm; | |
269 | struct vm_area_struct *vma = walk->vma; | |
270 | spinlock_t *ptl; | |
271 | pte_t *orig_pte, *pte, ptent; | |
272 | struct page *page; | |
64b42bc1 | 273 | int nr_swap = 0; |
854e9ed0 MK |
274 | |
275 | split_huge_pmd(vma, pmd, addr); | |
276 | if (pmd_trans_unstable(pmd)) | |
277 | return 0; | |
278 | ||
279 | orig_pte = pte = pte_offset_map_lock(mm, pmd, addr, &ptl); | |
280 | arch_enter_lazy_mmu_mode(); | |
281 | for (; addr != end; pte++, addr += PAGE_SIZE) { | |
282 | ptent = *pte; | |
283 | ||
64b42bc1 | 284 | if (pte_none(ptent)) |
854e9ed0 | 285 | continue; |
64b42bc1 MK |
286 | /* |
287 | * If the pte has swp_entry, just clear page table to | |
288 | * prevent swap-in which is more expensive rather than | |
289 | * (page allocation + zeroing). | |
290 | */ | |
291 | if (!pte_present(ptent)) { | |
292 | swp_entry_t entry; | |
293 | ||
294 | entry = pte_to_swp_entry(ptent); | |
295 | if (non_swap_entry(entry)) | |
296 | continue; | |
297 | nr_swap--; | |
298 | free_swap_and_cache(entry); | |
299 | pte_clear_not_present_full(mm, addr, pte, tlb->fullmm); | |
300 | continue; | |
301 | } | |
854e9ed0 MK |
302 | |
303 | page = vm_normal_page(vma, addr, ptent); | |
304 | if (!page) | |
305 | continue; | |
306 | ||
307 | /* | |
308 | * If pmd isn't transhuge but the page is THP and | |
309 | * is owned by only this process, split it and | |
310 | * deactivate all pages. | |
311 | */ | |
312 | if (PageTransCompound(page)) { | |
313 | if (page_mapcount(page) != 1) | |
314 | goto out; | |
315 | get_page(page); | |
316 | if (!trylock_page(page)) { | |
317 | put_page(page); | |
318 | goto out; | |
319 | } | |
320 | pte_unmap_unlock(orig_pte, ptl); | |
321 | if (split_huge_page(page)) { | |
322 | unlock_page(page); | |
323 | put_page(page); | |
324 | pte_offset_map_lock(mm, pmd, addr, &ptl); | |
325 | goto out; | |
326 | } | |
327 | put_page(page); | |
328 | unlock_page(page); | |
329 | pte = pte_offset_map_lock(mm, pmd, addr, &ptl); | |
330 | pte--; | |
331 | addr -= PAGE_SIZE; | |
332 | continue; | |
333 | } | |
334 | ||
335 | VM_BUG_ON_PAGE(PageTransCompound(page), page); | |
336 | ||
337 | if (PageSwapCache(page) || PageDirty(page)) { | |
338 | if (!trylock_page(page)) | |
339 | continue; | |
340 | /* | |
341 | * If page is shared with others, we couldn't clear | |
342 | * PG_dirty of the page. | |
343 | */ | |
344 | if (page_mapcount(page) != 1) { | |
345 | unlock_page(page); | |
346 | continue; | |
347 | } | |
348 | ||
349 | if (PageSwapCache(page) && !try_to_free_swap(page)) { | |
350 | unlock_page(page); | |
351 | continue; | |
352 | } | |
353 | ||
354 | ClearPageDirty(page); | |
355 | unlock_page(page); | |
356 | } | |
357 | ||
358 | if (pte_young(ptent) || pte_dirty(ptent)) { | |
359 | /* | |
360 | * Some of architecture(ex, PPC) don't update TLB | |
361 | * with set_pte_at and tlb_remove_tlb_entry so for | |
362 | * the portability, remap the pte with old|clean | |
363 | * after pte clearing. | |
364 | */ | |
365 | ptent = ptep_get_and_clear_full(mm, addr, pte, | |
366 | tlb->fullmm); | |
367 | ||
368 | ptent = pte_mkold(ptent); | |
369 | ptent = pte_mkclean(ptent); | |
370 | set_pte_at(mm, addr, pte, ptent); | |
10853a03 MK |
371 | if (PageActive(page)) |
372 | deactivate_page(page); | |
854e9ed0 MK |
373 | tlb_remove_tlb_entry(tlb, pte, addr); |
374 | } | |
375 | } | |
376 | out: | |
64b42bc1 MK |
377 | if (nr_swap) { |
378 | if (current->mm == mm) | |
379 | sync_mm_rss(mm); | |
380 | ||
381 | add_mm_counter(mm, MM_SWAPENTS, nr_swap); | |
382 | } | |
854e9ed0 MK |
383 | arch_leave_lazy_mmu_mode(); |
384 | pte_unmap_unlock(orig_pte, ptl); | |
385 | cond_resched(); | |
386 | return 0; | |
387 | } | |
388 | ||
389 | static void madvise_free_page_range(struct mmu_gather *tlb, | |
390 | struct vm_area_struct *vma, | |
391 | unsigned long addr, unsigned long end) | |
392 | { | |
393 | struct mm_walk free_walk = { | |
394 | .pmd_entry = madvise_free_pte_range, | |
395 | .mm = vma->vm_mm, | |
396 | .private = tlb, | |
397 | }; | |
398 | ||
399 | tlb_start_vma(tlb, vma); | |
400 | walk_page_range(addr, end, &free_walk); | |
401 | tlb_end_vma(tlb, vma); | |
402 | } | |
403 | ||
404 | static int madvise_free_single_vma(struct vm_area_struct *vma, | |
405 | unsigned long start_addr, unsigned long end_addr) | |
406 | { | |
407 | unsigned long start, end; | |
408 | struct mm_struct *mm = vma->vm_mm; | |
409 | struct mmu_gather tlb; | |
410 | ||
411 | if (vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP)) | |
412 | return -EINVAL; | |
413 | ||
414 | /* MADV_FREE works for only anon vma at the moment */ | |
415 | if (!vma_is_anonymous(vma)) | |
416 | return -EINVAL; | |
417 | ||
418 | start = max(vma->vm_start, start_addr); | |
419 | if (start >= vma->vm_end) | |
420 | return -EINVAL; | |
421 | end = min(vma->vm_end, end_addr); | |
422 | if (end <= vma->vm_start) | |
423 | return -EINVAL; | |
424 | ||
425 | lru_add_drain(); | |
426 | tlb_gather_mmu(&tlb, mm, start, end); | |
427 | update_hiwater_rss(mm); | |
428 | ||
429 | mmu_notifier_invalidate_range_start(mm, start, end); | |
430 | madvise_free_page_range(&tlb, vma, start, end); | |
431 | mmu_notifier_invalidate_range_end(mm, start, end); | |
432 | tlb_finish_mmu(&tlb, start, end); | |
433 | ||
434 | return 0; | |
435 | } | |
436 | ||
437 | static long madvise_free(struct vm_area_struct *vma, | |
438 | struct vm_area_struct **prev, | |
439 | unsigned long start, unsigned long end) | |
440 | { | |
441 | *prev = vma; | |
442 | return madvise_free_single_vma(vma, start, end); | |
443 | } | |
444 | ||
1da177e4 LT |
445 | /* |
446 | * Application no longer needs these pages. If the pages are dirty, | |
447 | * it's OK to just throw them away. The app will be more careful about | |
448 | * data it wants to keep. Be sure to free swap resources too. The | |
7e6cbea3 | 449 | * zap_page_range call sets things up for shrink_active_list to actually free |
1da177e4 LT |
450 | * these pages later if no one else has touched them in the meantime, |
451 | * although we could add these pages to a global reuse list for | |
7e6cbea3 | 452 | * shrink_active_list to pick up before reclaiming other pages. |
1da177e4 LT |
453 | * |
454 | * NB: This interface discards data rather than pushes it out to swap, | |
455 | * as some implementations do. This has performance implications for | |
456 | * applications like large transactional databases which want to discard | |
457 | * pages in anonymous maps after committing to backing store the data | |
458 | * that was kept in them. There is no reason to write this data out to | |
459 | * the swap area if the application is discarding it. | |
460 | * | |
461 | * An interface that causes the system to free clean pages and flush | |
462 | * dirty pages is already available as msync(MS_INVALIDATE). | |
463 | */ | |
ec9bed9d VC |
464 | static long madvise_dontneed(struct vm_area_struct *vma, |
465 | struct vm_area_struct **prev, | |
1da177e4 LT |
466 | unsigned long start, unsigned long end) |
467 | { | |
05b74384 | 468 | *prev = vma; |
6aab341e | 469 | if (vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP)) |
1da177e4 LT |
470 | return -EINVAL; |
471 | ||
8a5f14a2 | 472 | zap_page_range(vma, start, end - start, NULL); |
1da177e4 LT |
473 | return 0; |
474 | } | |
475 | ||
f6b3ec23 BP |
476 | /* |
477 | * Application wants to free up the pages and associated backing store. | |
478 | * This is effectively punching a hole into the middle of a file. | |
f6b3ec23 BP |
479 | */ |
480 | static long madvise_remove(struct vm_area_struct *vma, | |
00e9fa2d | 481 | struct vm_area_struct **prev, |
f6b3ec23 BP |
482 | unsigned long start, unsigned long end) |
483 | { | |
3f31d075 | 484 | loff_t offset; |
90ed52eb | 485 | int error; |
9ab4233d | 486 | struct file *f; |
f6b3ec23 | 487 | |
90ed52eb | 488 | *prev = NULL; /* tell sys_madvise we drop mmap_sem */ |
00e9fa2d | 489 | |
72079ba0 | 490 | if (vma->vm_flags & VM_LOCKED) |
f6b3ec23 BP |
491 | return -EINVAL; |
492 | ||
9ab4233d AL |
493 | f = vma->vm_file; |
494 | ||
495 | if (!f || !f->f_mapping || !f->f_mapping->host) { | |
f6b3ec23 BP |
496 | return -EINVAL; |
497 | } | |
498 | ||
69cf0fac HD |
499 | if ((vma->vm_flags & (VM_SHARED|VM_WRITE)) != (VM_SHARED|VM_WRITE)) |
500 | return -EACCES; | |
501 | ||
f6b3ec23 BP |
502 | offset = (loff_t)(start - vma->vm_start) |
503 | + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); | |
90ed52eb | 504 | |
9ab4233d AL |
505 | /* |
506 | * Filesystem's fallocate may need to take i_mutex. We need to | |
507 | * explicitly grab a reference because the vma (and hence the | |
508 | * vma's reference to the file) can go away as soon as we drop | |
509 | * mmap_sem. | |
510 | */ | |
511 | get_file(f); | |
0a27a14a | 512 | up_read(¤t->mm->mmap_sem); |
72c72bdf | 513 | error = vfs_fallocate(f, |
3f31d075 HD |
514 | FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, |
515 | offset, end - start); | |
9ab4233d | 516 | fput(f); |
0a27a14a | 517 | down_read(¤t->mm->mmap_sem); |
90ed52eb | 518 | return error; |
f6b3ec23 BP |
519 | } |
520 | ||
9893e49d AK |
521 | #ifdef CONFIG_MEMORY_FAILURE |
522 | /* | |
523 | * Error injection support for memory error handling. | |
524 | */ | |
afcf938e | 525 | static int madvise_hwpoison(int bhv, unsigned long start, unsigned long end) |
9893e49d | 526 | { |
20cb6cab | 527 | struct page *p; |
9893e49d AK |
528 | if (!capable(CAP_SYS_ADMIN)) |
529 | return -EPERM; | |
20cb6cab WL |
530 | for (; start < end; start += PAGE_SIZE << |
531 | compound_order(compound_head(p))) { | |
325c4ef5 AM |
532 | int ret; |
533 | ||
534 | ret = get_user_pages_fast(start, 1, 0, &p); | |
9893e49d AK |
535 | if (ret != 1) |
536 | return ret; | |
325c4ef5 | 537 | |
29b4eede WL |
538 | if (PageHWPoison(p)) { |
539 | put_page(p); | |
540 | continue; | |
541 | } | |
afcf938e | 542 | if (bhv == MADV_SOFT_OFFLINE) { |
b194b8cd | 543 | pr_info("Soft offlining page %#lx at %#lx\n", |
afcf938e AK |
544 | page_to_pfn(p), start); |
545 | ret = soft_offline_page(p, MF_COUNT_INCREASED); | |
546 | if (ret) | |
8302423b | 547 | return ret; |
afcf938e AK |
548 | continue; |
549 | } | |
b194b8cd | 550 | pr_info("Injecting memory failure for page %#lx at %#lx\n", |
9893e49d AK |
551 | page_to_pfn(p), start); |
552 | /* Ignore return value for now */ | |
cd42f4a3 | 553 | memory_failure(page_to_pfn(p), 0, MF_COUNT_INCREASED); |
9893e49d | 554 | } |
325c4ef5 | 555 | return 0; |
9893e49d AK |
556 | } |
557 | #endif | |
558 | ||
165cd402 | 559 | static long |
560 | madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev, | |
561 | unsigned long start, unsigned long end, int behavior) | |
1da177e4 | 562 | { |
1da177e4 | 563 | switch (behavior) { |
f6b3ec23 | 564 | case MADV_REMOVE: |
3866ea90 | 565 | return madvise_remove(vma, prev, start, end); |
1da177e4 | 566 | case MADV_WILLNEED: |
3866ea90 | 567 | return madvise_willneed(vma, prev, start, end); |
854e9ed0 MK |
568 | case MADV_FREE: |
569 | /* | |
570 | * XXX: In this implementation, MADV_FREE works like | |
571 | * MADV_DONTNEED on swapless system or full swap. | |
572 | */ | |
573 | if (get_nr_swap_pages() > 0) | |
574 | return madvise_free(vma, prev, start, end); | |
575 | /* passthrough */ | |
1da177e4 | 576 | case MADV_DONTNEED: |
3866ea90 | 577 | return madvise_dontneed(vma, prev, start, end); |
1da177e4 | 578 | default: |
3866ea90 | 579 | return madvise_behavior(vma, prev, start, end, behavior); |
1da177e4 | 580 | } |
1da177e4 LT |
581 | } |
582 | ||
1ecef9ed | 583 | static bool |
75927af8 NP |
584 | madvise_behavior_valid(int behavior) |
585 | { | |
586 | switch (behavior) { | |
587 | case MADV_DOFORK: | |
588 | case MADV_DONTFORK: | |
589 | case MADV_NORMAL: | |
590 | case MADV_SEQUENTIAL: | |
591 | case MADV_RANDOM: | |
592 | case MADV_REMOVE: | |
593 | case MADV_WILLNEED: | |
594 | case MADV_DONTNEED: | |
854e9ed0 | 595 | case MADV_FREE: |
f8af4da3 HD |
596 | #ifdef CONFIG_KSM |
597 | case MADV_MERGEABLE: | |
598 | case MADV_UNMERGEABLE: | |
0af4e98b AA |
599 | #endif |
600 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE | |
601 | case MADV_HUGEPAGE: | |
a664b2d8 | 602 | case MADV_NOHUGEPAGE: |
f8af4da3 | 603 | #endif |
accb61fe JB |
604 | case MADV_DONTDUMP: |
605 | case MADV_DODUMP: | |
1ecef9ed | 606 | return true; |
75927af8 NP |
607 | |
608 | default: | |
1ecef9ed | 609 | return false; |
75927af8 NP |
610 | } |
611 | } | |
3866ea90 | 612 | |
1da177e4 LT |
613 | /* |
614 | * The madvise(2) system call. | |
615 | * | |
616 | * Applications can use madvise() to advise the kernel how it should | |
617 | * handle paging I/O in this VM area. The idea is to help the kernel | |
618 | * use appropriate read-ahead and caching techniques. The information | |
619 | * provided is advisory only, and can be safely disregarded by the | |
620 | * kernel without affecting the correct operation of the application. | |
621 | * | |
622 | * behavior values: | |
623 | * MADV_NORMAL - the default behavior is to read clusters. This | |
624 | * results in some read-ahead and read-behind. | |
625 | * MADV_RANDOM - the system should read the minimum amount of data | |
626 | * on any access, since it is unlikely that the appli- | |
627 | * cation will need more than what it asks for. | |
628 | * MADV_SEQUENTIAL - pages in the given range will probably be accessed | |
629 | * once, so they can be aggressively read ahead, and | |
630 | * can be freed soon after they are accessed. | |
631 | * MADV_WILLNEED - the application is notifying the system to read | |
632 | * some pages ahead. | |
633 | * MADV_DONTNEED - the application is finished with the given range, | |
634 | * so the kernel can free resources associated with it. | |
f6b3ec23 BP |
635 | * MADV_REMOVE - the application wants to free up the given range of |
636 | * pages and associated backing store. | |
3866ea90 HD |
637 | * MADV_DONTFORK - omit this area from child's address space when forking: |
638 | * typically, to avoid COWing pages pinned by get_user_pages(). | |
639 | * MADV_DOFORK - cancel MADV_DONTFORK: no longer omit this area when forking. | |
f8af4da3 HD |
640 | * MADV_MERGEABLE - the application recommends that KSM try to merge pages in |
641 | * this area with pages of identical content from other such areas. | |
642 | * MADV_UNMERGEABLE- cancel MADV_MERGEABLE: no longer merge pages with others. | |
1da177e4 LT |
643 | * |
644 | * return values: | |
645 | * zero - success | |
646 | * -EINVAL - start + len < 0, start is not page-aligned, | |
647 | * "behavior" is not a valid value, or application | |
648 | * is attempting to release locked or shared pages. | |
649 | * -ENOMEM - addresses in the specified range are not currently | |
650 | * mapped, or are outside the AS of the process. | |
651 | * -EIO - an I/O error occurred while paging in data. | |
652 | * -EBADF - map exists, but area maps something that isn't a file. | |
653 | * -EAGAIN - a kernel resource was temporarily unavailable. | |
654 | */ | |
3480b257 | 655 | SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior) |
1da177e4 | 656 | { |
05b74384 | 657 | unsigned long end, tmp; |
ec9bed9d | 658 | struct vm_area_struct *vma, *prev; |
1da177e4 LT |
659 | int unmapped_error = 0; |
660 | int error = -EINVAL; | |
f7977793 | 661 | int write; |
1da177e4 | 662 | size_t len; |
1998cc04 | 663 | struct blk_plug plug; |
1da177e4 | 664 | |
9893e49d | 665 | #ifdef CONFIG_MEMORY_FAILURE |
afcf938e AK |
666 | if (behavior == MADV_HWPOISON || behavior == MADV_SOFT_OFFLINE) |
667 | return madvise_hwpoison(behavior, start, start+len_in); | |
9893e49d | 668 | #endif |
75927af8 NP |
669 | if (!madvise_behavior_valid(behavior)) |
670 | return error; | |
671 | ||
1da177e4 | 672 | if (start & ~PAGE_MASK) |
84d96d89 | 673 | return error; |
1da177e4 LT |
674 | len = (len_in + ~PAGE_MASK) & PAGE_MASK; |
675 | ||
676 | /* Check to see whether len was rounded up from small -ve to zero */ | |
677 | if (len_in && !len) | |
84d96d89 | 678 | return error; |
1da177e4 LT |
679 | |
680 | end = start + len; | |
681 | if (end < start) | |
84d96d89 | 682 | return error; |
1da177e4 LT |
683 | |
684 | error = 0; | |
685 | if (end == start) | |
84d96d89 RV |
686 | return error; |
687 | ||
688 | write = madvise_need_mmap_write(behavior); | |
689 | if (write) | |
690 | down_write(¤t->mm->mmap_sem); | |
691 | else | |
692 | down_read(¤t->mm->mmap_sem); | |
1da177e4 LT |
693 | |
694 | /* | |
695 | * If the interval [start,end) covers some unmapped address | |
696 | * ranges, just ignore them, but return -ENOMEM at the end. | |
05b74384 | 697 | * - different from the way of handling in mlock etc. |
1da177e4 | 698 | */ |
05b74384 | 699 | vma = find_vma_prev(current->mm, start, &prev); |
836d5ffd HD |
700 | if (vma && start > vma->vm_start) |
701 | prev = vma; | |
702 | ||
1998cc04 | 703 | blk_start_plug(&plug); |
1da177e4 LT |
704 | for (;;) { |
705 | /* Still start < end. */ | |
706 | error = -ENOMEM; | |
707 | if (!vma) | |
84d96d89 | 708 | goto out; |
1da177e4 | 709 | |
05b74384 | 710 | /* Here start < (end|vma->vm_end). */ |
1da177e4 LT |
711 | if (start < vma->vm_start) { |
712 | unmapped_error = -ENOMEM; | |
713 | start = vma->vm_start; | |
05b74384 | 714 | if (start >= end) |
84d96d89 | 715 | goto out; |
1da177e4 LT |
716 | } |
717 | ||
05b74384 PM |
718 | /* Here vma->vm_start <= start < (end|vma->vm_end) */ |
719 | tmp = vma->vm_end; | |
720 | if (end < tmp) | |
721 | tmp = end; | |
1da177e4 | 722 | |
05b74384 PM |
723 | /* Here vma->vm_start <= start < tmp <= (end|vma->vm_end). */ |
724 | error = madvise_vma(vma, &prev, start, tmp, behavior); | |
1da177e4 | 725 | if (error) |
84d96d89 | 726 | goto out; |
05b74384 | 727 | start = tmp; |
90ed52eb | 728 | if (prev && start < prev->vm_end) |
05b74384 PM |
729 | start = prev->vm_end; |
730 | error = unmapped_error; | |
731 | if (start >= end) | |
84d96d89 | 732 | goto out; |
90ed52eb HD |
733 | if (prev) |
734 | vma = prev->vm_next; | |
735 | else /* madvise_remove dropped mmap_sem */ | |
736 | vma = find_vma(current->mm, start); | |
1da177e4 | 737 | } |
1da177e4 | 738 | out: |
84d96d89 | 739 | blk_finish_plug(&plug); |
f7977793 | 740 | if (write) |
0a27a14a NP |
741 | up_write(¤t->mm->mmap_sem); |
742 | else | |
743 | up_read(¤t->mm->mmap_sem); | |
744 | ||
1da177e4 LT |
745 | return error; |
746 | } |