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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> |
05ce7724 | 13 | #include <linux/userfaultfd_k.h> |
1da177e4 | 14 | #include <linux/hugetlb.h> |
3f31d075 | 15 | #include <linux/falloc.h> |
e8edc6e0 | 16 | #include <linux/sched.h> |
f8af4da3 | 17 | #include <linux/ksm.h> |
3f31d075 | 18 | #include <linux/fs.h> |
9ab4233d | 19 | #include <linux/file.h> |
1998cc04 | 20 | #include <linux/blkdev.h> |
66114cad | 21 | #include <linux/backing-dev.h> |
1998cc04 SL |
22 | #include <linux/swap.h> |
23 | #include <linux/swapops.h> | |
854e9ed0 MK |
24 | #include <linux/mmu_notifier.h> |
25 | ||
26 | #include <asm/tlb.h> | |
1da177e4 | 27 | |
23519073 KS |
28 | #include "internal.h" |
29 | ||
0a27a14a NP |
30 | /* |
31 | * Any behaviour which results in changes to the vma->vm_flags needs to | |
32 | * take mmap_sem for writing. Others, which simply traverse vmas, need | |
33 | * to only take it for reading. | |
34 | */ | |
35 | static int madvise_need_mmap_write(int behavior) | |
36 | { | |
37 | switch (behavior) { | |
38 | case MADV_REMOVE: | |
39 | case MADV_WILLNEED: | |
40 | case MADV_DONTNEED: | |
854e9ed0 | 41 | case MADV_FREE: |
0a27a14a NP |
42 | return 0; |
43 | default: | |
44 | /* be safe, default to 1. list exceptions explicitly */ | |
45 | return 1; | |
46 | } | |
47 | } | |
48 | ||
1da177e4 LT |
49 | /* |
50 | * We can potentially split a vm area into separate | |
51 | * areas, each area with its own behavior. | |
52 | */ | |
ec9bed9d | 53 | static long madvise_behavior(struct vm_area_struct *vma, |
05b74384 PM |
54 | struct vm_area_struct **prev, |
55 | unsigned long start, unsigned long end, int behavior) | |
1da177e4 | 56 | { |
ec9bed9d | 57 | struct mm_struct *mm = vma->vm_mm; |
1da177e4 | 58 | int error = 0; |
05b74384 | 59 | pgoff_t pgoff; |
3866ea90 | 60 | unsigned long new_flags = vma->vm_flags; |
e798c6e8 PM |
61 | |
62 | switch (behavior) { | |
f8225661 MT |
63 | case MADV_NORMAL: |
64 | new_flags = new_flags & ~VM_RAND_READ & ~VM_SEQ_READ; | |
65 | break; | |
e798c6e8 | 66 | case MADV_SEQUENTIAL: |
f8225661 | 67 | new_flags = (new_flags & ~VM_RAND_READ) | VM_SEQ_READ; |
e798c6e8 PM |
68 | break; |
69 | case MADV_RANDOM: | |
f8225661 | 70 | new_flags = (new_flags & ~VM_SEQ_READ) | VM_RAND_READ; |
e798c6e8 | 71 | break; |
f8225661 MT |
72 | case MADV_DONTFORK: |
73 | new_flags |= VM_DONTCOPY; | |
74 | break; | |
75 | case MADV_DOFORK: | |
3866ea90 HD |
76 | if (vma->vm_flags & VM_IO) { |
77 | error = -EINVAL; | |
78 | goto out; | |
79 | } | |
f8225661 | 80 | new_flags &= ~VM_DONTCOPY; |
e798c6e8 | 81 | break; |
accb61fe | 82 | case MADV_DONTDUMP: |
0103bd16 | 83 | new_flags |= VM_DONTDUMP; |
accb61fe JB |
84 | break; |
85 | case MADV_DODUMP: | |
0103bd16 KK |
86 | if (new_flags & VM_SPECIAL) { |
87 | error = -EINVAL; | |
88 | goto out; | |
89 | } | |
90 | new_flags &= ~VM_DONTDUMP; | |
accb61fe | 91 | break; |
f8af4da3 HD |
92 | case MADV_MERGEABLE: |
93 | case MADV_UNMERGEABLE: | |
94 | error = ksm_madvise(vma, start, end, behavior, &new_flags); | |
95 | if (error) | |
96 | goto out; | |
97 | break; | |
0af4e98b | 98 | case MADV_HUGEPAGE: |
a664b2d8 | 99 | case MADV_NOHUGEPAGE: |
60ab3244 | 100 | error = hugepage_madvise(vma, &new_flags, behavior); |
0af4e98b AA |
101 | if (error) |
102 | goto out; | |
103 | break; | |
e798c6e8 PM |
104 | } |
105 | ||
05b74384 PM |
106 | if (new_flags == vma->vm_flags) { |
107 | *prev = vma; | |
836d5ffd | 108 | goto out; |
05b74384 PM |
109 | } |
110 | ||
111 | pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); | |
112 | *prev = vma_merge(mm, *prev, start, end, new_flags, vma->anon_vma, | |
19a809af AA |
113 | vma->vm_file, pgoff, vma_policy(vma), |
114 | vma->vm_userfaultfd_ctx); | |
05b74384 PM |
115 | if (*prev) { |
116 | vma = *prev; | |
117 | goto success; | |
118 | } | |
119 | ||
120 | *prev = vma; | |
1da177e4 LT |
121 | |
122 | if (start != vma->vm_start) { | |
123 | error = split_vma(mm, vma, start, 1); | |
124 | if (error) | |
125 | goto out; | |
126 | } | |
127 | ||
128 | if (end != vma->vm_end) { | |
129 | error = split_vma(mm, vma, end, 0); | |
130 | if (error) | |
131 | goto out; | |
132 | } | |
133 | ||
836d5ffd | 134 | success: |
1da177e4 LT |
135 | /* |
136 | * vm_flags is protected by the mmap_sem held in write mode. | |
137 | */ | |
e798c6e8 | 138 | vma->vm_flags = new_flags; |
1da177e4 LT |
139 | |
140 | out: | |
141 | if (error == -ENOMEM) | |
142 | error = -EAGAIN; | |
143 | return error; | |
144 | } | |
145 | ||
1998cc04 SL |
146 | #ifdef CONFIG_SWAP |
147 | static int swapin_walk_pmd_entry(pmd_t *pmd, unsigned long start, | |
148 | unsigned long end, struct mm_walk *walk) | |
149 | { | |
150 | pte_t *orig_pte; | |
151 | struct vm_area_struct *vma = walk->private; | |
152 | unsigned long index; | |
153 | ||
154 | if (pmd_none_or_trans_huge_or_clear_bad(pmd)) | |
155 | return 0; | |
156 | ||
157 | for (index = start; index != end; index += PAGE_SIZE) { | |
158 | pte_t pte; | |
159 | swp_entry_t entry; | |
160 | struct page *page; | |
161 | spinlock_t *ptl; | |
162 | ||
163 | orig_pte = pte_offset_map_lock(vma->vm_mm, pmd, start, &ptl); | |
164 | pte = *(orig_pte + ((index - start) / PAGE_SIZE)); | |
165 | pte_unmap_unlock(orig_pte, ptl); | |
166 | ||
0661a336 | 167 | if (pte_present(pte) || pte_none(pte)) |
1998cc04 SL |
168 | continue; |
169 | entry = pte_to_swp_entry(pte); | |
170 | if (unlikely(non_swap_entry(entry))) | |
171 | continue; | |
172 | ||
173 | page = read_swap_cache_async(entry, GFP_HIGHUSER_MOVABLE, | |
174 | vma, index); | |
175 | if (page) | |
09cbfeaf | 176 | put_page(page); |
1998cc04 SL |
177 | } |
178 | ||
179 | return 0; | |
180 | } | |
181 | ||
182 | static void force_swapin_readahead(struct vm_area_struct *vma, | |
183 | unsigned long start, unsigned long end) | |
184 | { | |
185 | struct mm_walk walk = { | |
186 | .mm = vma->vm_mm, | |
187 | .pmd_entry = swapin_walk_pmd_entry, | |
188 | .private = vma, | |
189 | }; | |
190 | ||
191 | walk_page_range(start, end, &walk); | |
192 | ||
193 | lru_add_drain(); /* Push any new pages onto the LRU now */ | |
194 | } | |
195 | ||
196 | static void force_shm_swapin_readahead(struct vm_area_struct *vma, | |
197 | unsigned long start, unsigned long end, | |
198 | struct address_space *mapping) | |
199 | { | |
200 | pgoff_t index; | |
201 | struct page *page; | |
202 | swp_entry_t swap; | |
203 | ||
204 | for (; start < end; start += PAGE_SIZE) { | |
205 | index = ((start - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; | |
206 | ||
55231e5c | 207 | page = find_get_entry(mapping, index); |
1998cc04 SL |
208 | if (!radix_tree_exceptional_entry(page)) { |
209 | if (page) | |
09cbfeaf | 210 | put_page(page); |
1998cc04 SL |
211 | continue; |
212 | } | |
213 | swap = radix_to_swp_entry(page); | |
214 | page = read_swap_cache_async(swap, GFP_HIGHUSER_MOVABLE, | |
215 | NULL, 0); | |
216 | if (page) | |
09cbfeaf | 217 | put_page(page); |
1998cc04 SL |
218 | } |
219 | ||
220 | lru_add_drain(); /* Push any new pages onto the LRU now */ | |
221 | } | |
222 | #endif /* CONFIG_SWAP */ | |
223 | ||
1da177e4 LT |
224 | /* |
225 | * Schedule all required I/O operations. Do not wait for completion. | |
226 | */ | |
ec9bed9d VC |
227 | static long madvise_willneed(struct vm_area_struct *vma, |
228 | struct vm_area_struct **prev, | |
1da177e4 LT |
229 | unsigned long start, unsigned long end) |
230 | { | |
231 | struct file *file = vma->vm_file; | |
232 | ||
1998cc04 | 233 | #ifdef CONFIG_SWAP |
97b713ba | 234 | if (!file) { |
1998cc04 | 235 | *prev = vma; |
97b713ba | 236 | force_swapin_readahead(vma, start, end); |
1998cc04 SL |
237 | return 0; |
238 | } | |
1998cc04 | 239 | |
97b713ba CH |
240 | if (shmem_mapping(file->f_mapping)) { |
241 | *prev = vma; | |
242 | force_shm_swapin_readahead(vma, start, end, | |
243 | file->f_mapping); | |
244 | return 0; | |
245 | } | |
246 | #else | |
1bef4003 S |
247 | if (!file) |
248 | return -EBADF; | |
97b713ba | 249 | #endif |
1bef4003 | 250 | |
e748dcd0 | 251 | if (IS_DAX(file_inode(file))) { |
fe77ba6f CO |
252 | /* no bad return value, but ignore advice */ |
253 | return 0; | |
254 | } | |
255 | ||
05b74384 | 256 | *prev = vma; |
1da177e4 LT |
257 | start = ((start - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; |
258 | if (end > vma->vm_end) | |
259 | end = vma->vm_end; | |
260 | end = ((end - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; | |
261 | ||
f7e839dd | 262 | force_page_cache_readahead(file->f_mapping, file, start, end - start); |
1da177e4 LT |
263 | return 0; |
264 | } | |
265 | ||
854e9ed0 MK |
266 | static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr, |
267 | unsigned long end, struct mm_walk *walk) | |
268 | ||
269 | { | |
270 | struct mmu_gather *tlb = walk->private; | |
271 | struct mm_struct *mm = tlb->mm; | |
272 | struct vm_area_struct *vma = walk->vma; | |
273 | spinlock_t *ptl; | |
274 | pte_t *orig_pte, *pte, ptent; | |
275 | struct page *page; | |
64b42bc1 | 276 | int nr_swap = 0; |
b8d3c4c3 MK |
277 | unsigned long next; |
278 | ||
279 | next = pmd_addr_end(addr, end); | |
280 | if (pmd_trans_huge(*pmd)) | |
281 | if (madvise_free_huge_pmd(tlb, vma, pmd, addr, next)) | |
282 | goto next; | |
854e9ed0 | 283 | |
854e9ed0 MK |
284 | if (pmd_trans_unstable(pmd)) |
285 | return 0; | |
286 | ||
07e32661 | 287 | tlb_remove_check_page_size_change(tlb, PAGE_SIZE); |
854e9ed0 MK |
288 | orig_pte = pte = pte_offset_map_lock(mm, pmd, addr, &ptl); |
289 | arch_enter_lazy_mmu_mode(); | |
290 | for (; addr != end; pte++, addr += PAGE_SIZE) { | |
291 | ptent = *pte; | |
292 | ||
64b42bc1 | 293 | if (pte_none(ptent)) |
854e9ed0 | 294 | continue; |
64b42bc1 MK |
295 | /* |
296 | * If the pte has swp_entry, just clear page table to | |
297 | * prevent swap-in which is more expensive rather than | |
298 | * (page allocation + zeroing). | |
299 | */ | |
300 | if (!pte_present(ptent)) { | |
301 | swp_entry_t entry; | |
302 | ||
303 | entry = pte_to_swp_entry(ptent); | |
304 | if (non_swap_entry(entry)) | |
305 | continue; | |
306 | nr_swap--; | |
307 | free_swap_and_cache(entry); | |
308 | pte_clear_not_present_full(mm, addr, pte, tlb->fullmm); | |
309 | continue; | |
310 | } | |
854e9ed0 MK |
311 | |
312 | page = vm_normal_page(vma, addr, ptent); | |
313 | if (!page) | |
314 | continue; | |
315 | ||
316 | /* | |
317 | * If pmd isn't transhuge but the page is THP and | |
318 | * is owned by only this process, split it and | |
319 | * deactivate all pages. | |
320 | */ | |
321 | if (PageTransCompound(page)) { | |
322 | if (page_mapcount(page) != 1) | |
323 | goto out; | |
324 | get_page(page); | |
325 | if (!trylock_page(page)) { | |
326 | put_page(page); | |
327 | goto out; | |
328 | } | |
329 | pte_unmap_unlock(orig_pte, ptl); | |
330 | if (split_huge_page(page)) { | |
331 | unlock_page(page); | |
332 | put_page(page); | |
333 | pte_offset_map_lock(mm, pmd, addr, &ptl); | |
334 | goto out; | |
335 | } | |
336 | put_page(page); | |
337 | unlock_page(page); | |
338 | pte = pte_offset_map_lock(mm, pmd, addr, &ptl); | |
339 | pte--; | |
340 | addr -= PAGE_SIZE; | |
341 | continue; | |
342 | } | |
343 | ||
344 | VM_BUG_ON_PAGE(PageTransCompound(page), page); | |
345 | ||
346 | if (PageSwapCache(page) || PageDirty(page)) { | |
347 | if (!trylock_page(page)) | |
348 | continue; | |
349 | /* | |
350 | * If page is shared with others, we couldn't clear | |
351 | * PG_dirty of the page. | |
352 | */ | |
353 | if (page_mapcount(page) != 1) { | |
354 | unlock_page(page); | |
355 | continue; | |
356 | } | |
357 | ||
358 | if (PageSwapCache(page) && !try_to_free_swap(page)) { | |
359 | unlock_page(page); | |
360 | continue; | |
361 | } | |
362 | ||
363 | ClearPageDirty(page); | |
364 | unlock_page(page); | |
365 | } | |
366 | ||
367 | if (pte_young(ptent) || pte_dirty(ptent)) { | |
368 | /* | |
369 | * Some of architecture(ex, PPC) don't update TLB | |
370 | * with set_pte_at and tlb_remove_tlb_entry so for | |
371 | * the portability, remap the pte with old|clean | |
372 | * after pte clearing. | |
373 | */ | |
374 | ptent = ptep_get_and_clear_full(mm, addr, pte, | |
375 | tlb->fullmm); | |
376 | ||
377 | ptent = pte_mkold(ptent); | |
378 | ptent = pte_mkclean(ptent); | |
379 | set_pte_at(mm, addr, pte, ptent); | |
10853a03 MK |
380 | if (PageActive(page)) |
381 | deactivate_page(page); | |
854e9ed0 MK |
382 | tlb_remove_tlb_entry(tlb, pte, addr); |
383 | } | |
384 | } | |
385 | out: | |
64b42bc1 MK |
386 | if (nr_swap) { |
387 | if (current->mm == mm) | |
388 | sync_mm_rss(mm); | |
389 | ||
390 | add_mm_counter(mm, MM_SWAPENTS, nr_swap); | |
391 | } | |
854e9ed0 MK |
392 | arch_leave_lazy_mmu_mode(); |
393 | pte_unmap_unlock(orig_pte, ptl); | |
394 | cond_resched(); | |
b8d3c4c3 | 395 | next: |
854e9ed0 MK |
396 | return 0; |
397 | } | |
398 | ||
399 | static void madvise_free_page_range(struct mmu_gather *tlb, | |
400 | struct vm_area_struct *vma, | |
401 | unsigned long addr, unsigned long end) | |
402 | { | |
403 | struct mm_walk free_walk = { | |
404 | .pmd_entry = madvise_free_pte_range, | |
405 | .mm = vma->vm_mm, | |
406 | .private = tlb, | |
407 | }; | |
408 | ||
409 | tlb_start_vma(tlb, vma); | |
410 | walk_page_range(addr, end, &free_walk); | |
411 | tlb_end_vma(tlb, vma); | |
412 | } | |
413 | ||
414 | static int madvise_free_single_vma(struct vm_area_struct *vma, | |
415 | unsigned long start_addr, unsigned long end_addr) | |
416 | { | |
417 | unsigned long start, end; | |
418 | struct mm_struct *mm = vma->vm_mm; | |
419 | struct mmu_gather tlb; | |
420 | ||
421 | if (vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP)) | |
422 | return -EINVAL; | |
423 | ||
424 | /* MADV_FREE works for only anon vma at the moment */ | |
425 | if (!vma_is_anonymous(vma)) | |
426 | return -EINVAL; | |
427 | ||
428 | start = max(vma->vm_start, start_addr); | |
429 | if (start >= vma->vm_end) | |
430 | return -EINVAL; | |
431 | end = min(vma->vm_end, end_addr); | |
432 | if (end <= vma->vm_start) | |
433 | return -EINVAL; | |
434 | ||
435 | lru_add_drain(); | |
436 | tlb_gather_mmu(&tlb, mm, start, end); | |
437 | update_hiwater_rss(mm); | |
438 | ||
439 | mmu_notifier_invalidate_range_start(mm, start, end); | |
440 | madvise_free_page_range(&tlb, vma, start, end); | |
441 | mmu_notifier_invalidate_range_end(mm, start, end); | |
442 | tlb_finish_mmu(&tlb, start, end); | |
443 | ||
444 | return 0; | |
445 | } | |
446 | ||
447 | static long madvise_free(struct vm_area_struct *vma, | |
448 | struct vm_area_struct **prev, | |
449 | unsigned long start, unsigned long end) | |
450 | { | |
451 | *prev = vma; | |
452 | return madvise_free_single_vma(vma, start, end); | |
453 | } | |
454 | ||
1da177e4 LT |
455 | /* |
456 | * Application no longer needs these pages. If the pages are dirty, | |
457 | * it's OK to just throw them away. The app will be more careful about | |
458 | * data it wants to keep. Be sure to free swap resources too. The | |
7e6cbea3 | 459 | * zap_page_range call sets things up for shrink_active_list to actually free |
1da177e4 LT |
460 | * these pages later if no one else has touched them in the meantime, |
461 | * although we could add these pages to a global reuse list for | |
7e6cbea3 | 462 | * shrink_active_list to pick up before reclaiming other pages. |
1da177e4 LT |
463 | * |
464 | * NB: This interface discards data rather than pushes it out to swap, | |
465 | * as some implementations do. This has performance implications for | |
466 | * applications like large transactional databases which want to discard | |
467 | * pages in anonymous maps after committing to backing store the data | |
468 | * that was kept in them. There is no reason to write this data out to | |
469 | * the swap area if the application is discarding it. | |
470 | * | |
471 | * An interface that causes the system to free clean pages and flush | |
472 | * dirty pages is already available as msync(MS_INVALIDATE). | |
473 | */ | |
ec9bed9d VC |
474 | static long madvise_dontneed(struct vm_area_struct *vma, |
475 | struct vm_area_struct **prev, | |
1da177e4 LT |
476 | unsigned long start, unsigned long end) |
477 | { | |
05b74384 | 478 | *prev = vma; |
23519073 | 479 | if (!can_madv_dontneed_vma(vma)) |
1da177e4 LT |
480 | return -EINVAL; |
481 | ||
d811914d | 482 | userfaultfd_remove(vma, prev, start, end); |
ecf1385d | 483 | zap_page_range(vma, start, end - start); |
1da177e4 LT |
484 | return 0; |
485 | } | |
486 | ||
f6b3ec23 BP |
487 | /* |
488 | * Application wants to free up the pages and associated backing store. | |
489 | * This is effectively punching a hole into the middle of a file. | |
f6b3ec23 BP |
490 | */ |
491 | static long madvise_remove(struct vm_area_struct *vma, | |
00e9fa2d | 492 | struct vm_area_struct **prev, |
f6b3ec23 BP |
493 | unsigned long start, unsigned long end) |
494 | { | |
3f31d075 | 495 | loff_t offset; |
90ed52eb | 496 | int error; |
9ab4233d | 497 | struct file *f; |
f6b3ec23 | 498 | |
90ed52eb | 499 | *prev = NULL; /* tell sys_madvise we drop mmap_sem */ |
00e9fa2d | 500 | |
72079ba0 | 501 | if (vma->vm_flags & VM_LOCKED) |
f6b3ec23 BP |
502 | return -EINVAL; |
503 | ||
9ab4233d AL |
504 | f = vma->vm_file; |
505 | ||
506 | if (!f || !f->f_mapping || !f->f_mapping->host) { | |
f6b3ec23 BP |
507 | return -EINVAL; |
508 | } | |
509 | ||
69cf0fac HD |
510 | if ((vma->vm_flags & (VM_SHARED|VM_WRITE)) != (VM_SHARED|VM_WRITE)) |
511 | return -EACCES; | |
512 | ||
f6b3ec23 BP |
513 | offset = (loff_t)(start - vma->vm_start) |
514 | + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); | |
90ed52eb | 515 | |
9ab4233d AL |
516 | /* |
517 | * Filesystem's fallocate may need to take i_mutex. We need to | |
518 | * explicitly grab a reference because the vma (and hence the | |
519 | * vma's reference to the file) can go away as soon as we drop | |
520 | * mmap_sem. | |
521 | */ | |
522 | get_file(f); | |
a6bf53eb | 523 | userfaultfd_remove(vma, prev, start, end); |
0a27a14a | 524 | up_read(¤t->mm->mmap_sem); |
72c72bdf | 525 | error = vfs_fallocate(f, |
3f31d075 HD |
526 | FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, |
527 | offset, end - start); | |
9ab4233d | 528 | fput(f); |
0a27a14a | 529 | down_read(¤t->mm->mmap_sem); |
90ed52eb | 530 | return error; |
f6b3ec23 BP |
531 | } |
532 | ||
9893e49d AK |
533 | #ifdef CONFIG_MEMORY_FAILURE |
534 | /* | |
535 | * Error injection support for memory error handling. | |
536 | */ | |
afcf938e | 537 | static int madvise_hwpoison(int bhv, unsigned long start, unsigned long end) |
9893e49d | 538 | { |
20cb6cab | 539 | struct page *p; |
9893e49d AK |
540 | if (!capable(CAP_SYS_ADMIN)) |
541 | return -EPERM; | |
20cb6cab WL |
542 | for (; start < end; start += PAGE_SIZE << |
543 | compound_order(compound_head(p))) { | |
325c4ef5 AM |
544 | int ret; |
545 | ||
546 | ret = get_user_pages_fast(start, 1, 0, &p); | |
9893e49d AK |
547 | if (ret != 1) |
548 | return ret; | |
325c4ef5 | 549 | |
29b4eede WL |
550 | if (PageHWPoison(p)) { |
551 | put_page(p); | |
552 | continue; | |
553 | } | |
afcf938e | 554 | if (bhv == MADV_SOFT_OFFLINE) { |
b194b8cd | 555 | pr_info("Soft offlining page %#lx at %#lx\n", |
afcf938e AK |
556 | page_to_pfn(p), start); |
557 | ret = soft_offline_page(p, MF_COUNT_INCREASED); | |
558 | if (ret) | |
8302423b | 559 | return ret; |
afcf938e AK |
560 | continue; |
561 | } | |
b194b8cd | 562 | pr_info("Injecting memory failure for page %#lx at %#lx\n", |
9893e49d | 563 | page_to_pfn(p), start); |
23a003bf NH |
564 | ret = memory_failure(page_to_pfn(p), 0, MF_COUNT_INCREASED); |
565 | if (ret) | |
566 | return ret; | |
9893e49d | 567 | } |
325c4ef5 | 568 | return 0; |
9893e49d AK |
569 | } |
570 | #endif | |
571 | ||
165cd402 | 572 | static long |
573 | madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev, | |
574 | unsigned long start, unsigned long end, int behavior) | |
1da177e4 | 575 | { |
1da177e4 | 576 | switch (behavior) { |
f6b3ec23 | 577 | case MADV_REMOVE: |
3866ea90 | 578 | return madvise_remove(vma, prev, start, end); |
1da177e4 | 579 | case MADV_WILLNEED: |
3866ea90 | 580 | return madvise_willneed(vma, prev, start, end); |
854e9ed0 MK |
581 | case MADV_FREE: |
582 | /* | |
583 | * XXX: In this implementation, MADV_FREE works like | |
584 | * MADV_DONTNEED on swapless system or full swap. | |
585 | */ | |
586 | if (get_nr_swap_pages() > 0) | |
587 | return madvise_free(vma, prev, start, end); | |
588 | /* passthrough */ | |
1da177e4 | 589 | case MADV_DONTNEED: |
3866ea90 | 590 | return madvise_dontneed(vma, prev, start, end); |
1da177e4 | 591 | default: |
3866ea90 | 592 | return madvise_behavior(vma, prev, start, end, behavior); |
1da177e4 | 593 | } |
1da177e4 LT |
594 | } |
595 | ||
1ecef9ed | 596 | static bool |
75927af8 NP |
597 | madvise_behavior_valid(int behavior) |
598 | { | |
599 | switch (behavior) { | |
600 | case MADV_DOFORK: | |
601 | case MADV_DONTFORK: | |
602 | case MADV_NORMAL: | |
603 | case MADV_SEQUENTIAL: | |
604 | case MADV_RANDOM: | |
605 | case MADV_REMOVE: | |
606 | case MADV_WILLNEED: | |
607 | case MADV_DONTNEED: | |
854e9ed0 | 608 | case MADV_FREE: |
f8af4da3 HD |
609 | #ifdef CONFIG_KSM |
610 | case MADV_MERGEABLE: | |
611 | case MADV_UNMERGEABLE: | |
0af4e98b AA |
612 | #endif |
613 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE | |
614 | case MADV_HUGEPAGE: | |
a664b2d8 | 615 | case MADV_NOHUGEPAGE: |
f8af4da3 | 616 | #endif |
accb61fe JB |
617 | case MADV_DONTDUMP: |
618 | case MADV_DODUMP: | |
1ecef9ed | 619 | return true; |
75927af8 NP |
620 | |
621 | default: | |
1ecef9ed | 622 | return false; |
75927af8 NP |
623 | } |
624 | } | |
3866ea90 | 625 | |
1da177e4 LT |
626 | /* |
627 | * The madvise(2) system call. | |
628 | * | |
629 | * Applications can use madvise() to advise the kernel how it should | |
630 | * handle paging I/O in this VM area. The idea is to help the kernel | |
631 | * use appropriate read-ahead and caching techniques. The information | |
632 | * provided is advisory only, and can be safely disregarded by the | |
633 | * kernel without affecting the correct operation of the application. | |
634 | * | |
635 | * behavior values: | |
636 | * MADV_NORMAL - the default behavior is to read clusters. This | |
637 | * results in some read-ahead and read-behind. | |
638 | * MADV_RANDOM - the system should read the minimum amount of data | |
639 | * on any access, since it is unlikely that the appli- | |
640 | * cation will need more than what it asks for. | |
641 | * MADV_SEQUENTIAL - pages in the given range will probably be accessed | |
642 | * once, so they can be aggressively read ahead, and | |
643 | * can be freed soon after they are accessed. | |
644 | * MADV_WILLNEED - the application is notifying the system to read | |
645 | * some pages ahead. | |
646 | * MADV_DONTNEED - the application is finished with the given range, | |
647 | * so the kernel can free resources associated with it. | |
d7206a70 NH |
648 | * MADV_FREE - the application marks pages in the given range as lazy free, |
649 | * where actual purges are postponed until memory pressure happens. | |
f6b3ec23 BP |
650 | * MADV_REMOVE - the application wants to free up the given range of |
651 | * pages and associated backing store. | |
3866ea90 HD |
652 | * MADV_DONTFORK - omit this area from child's address space when forking: |
653 | * typically, to avoid COWing pages pinned by get_user_pages(). | |
654 | * MADV_DOFORK - cancel MADV_DONTFORK: no longer omit this area when forking. | |
d7206a70 NH |
655 | * MADV_HWPOISON - trigger memory error handler as if the given memory range |
656 | * were corrupted by unrecoverable hardware memory failure. | |
657 | * MADV_SOFT_OFFLINE - try to soft-offline the given range of memory. | |
f8af4da3 HD |
658 | * MADV_MERGEABLE - the application recommends that KSM try to merge pages in |
659 | * this area with pages of identical content from other such areas. | |
660 | * MADV_UNMERGEABLE- cancel MADV_MERGEABLE: no longer merge pages with others. | |
d7206a70 NH |
661 | * MADV_HUGEPAGE - the application wants to back the given range by transparent |
662 | * huge pages in the future. Existing pages might be coalesced and | |
663 | * new pages might be allocated as THP. | |
664 | * MADV_NOHUGEPAGE - mark the given range as not worth being backed by | |
665 | * transparent huge pages so the existing pages will not be | |
666 | * coalesced into THP and new pages will not be allocated as THP. | |
667 | * MADV_DONTDUMP - the application wants to prevent pages in the given range | |
668 | * from being included in its core dump. | |
669 | * MADV_DODUMP - cancel MADV_DONTDUMP: no longer exclude from core dump. | |
1da177e4 LT |
670 | * |
671 | * return values: | |
672 | * zero - success | |
673 | * -EINVAL - start + len < 0, start is not page-aligned, | |
674 | * "behavior" is not a valid value, or application | |
675 | * is attempting to release locked or shared pages. | |
676 | * -ENOMEM - addresses in the specified range are not currently | |
677 | * mapped, or are outside the AS of the process. | |
678 | * -EIO - an I/O error occurred while paging in data. | |
679 | * -EBADF - map exists, but area maps something that isn't a file. | |
680 | * -EAGAIN - a kernel resource was temporarily unavailable. | |
681 | */ | |
3480b257 | 682 | SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior) |
1da177e4 | 683 | { |
05b74384 | 684 | unsigned long end, tmp; |
ec9bed9d | 685 | struct vm_area_struct *vma, *prev; |
1da177e4 LT |
686 | int unmapped_error = 0; |
687 | int error = -EINVAL; | |
f7977793 | 688 | int write; |
1da177e4 | 689 | size_t len; |
1998cc04 | 690 | struct blk_plug plug; |
1da177e4 | 691 | |
9893e49d | 692 | #ifdef CONFIG_MEMORY_FAILURE |
afcf938e AK |
693 | if (behavior == MADV_HWPOISON || behavior == MADV_SOFT_OFFLINE) |
694 | return madvise_hwpoison(behavior, start, start+len_in); | |
9893e49d | 695 | #endif |
75927af8 NP |
696 | if (!madvise_behavior_valid(behavior)) |
697 | return error; | |
698 | ||
1da177e4 | 699 | if (start & ~PAGE_MASK) |
84d96d89 | 700 | return error; |
1da177e4 LT |
701 | len = (len_in + ~PAGE_MASK) & PAGE_MASK; |
702 | ||
703 | /* Check to see whether len was rounded up from small -ve to zero */ | |
704 | if (len_in && !len) | |
84d96d89 | 705 | return error; |
1da177e4 LT |
706 | |
707 | end = start + len; | |
708 | if (end < start) | |
84d96d89 | 709 | return error; |
1da177e4 LT |
710 | |
711 | error = 0; | |
712 | if (end == start) | |
84d96d89 RV |
713 | return error; |
714 | ||
715 | write = madvise_need_mmap_write(behavior); | |
dc0ef0df MH |
716 | if (write) { |
717 | if (down_write_killable(¤t->mm->mmap_sem)) | |
718 | return -EINTR; | |
719 | } else { | |
84d96d89 | 720 | down_read(¤t->mm->mmap_sem); |
dc0ef0df | 721 | } |
1da177e4 LT |
722 | |
723 | /* | |
724 | * If the interval [start,end) covers some unmapped address | |
725 | * ranges, just ignore them, but return -ENOMEM at the end. | |
05b74384 | 726 | * - different from the way of handling in mlock etc. |
1da177e4 | 727 | */ |
05b74384 | 728 | vma = find_vma_prev(current->mm, start, &prev); |
836d5ffd HD |
729 | if (vma && start > vma->vm_start) |
730 | prev = vma; | |
731 | ||
1998cc04 | 732 | blk_start_plug(&plug); |
1da177e4 LT |
733 | for (;;) { |
734 | /* Still start < end. */ | |
735 | error = -ENOMEM; | |
736 | if (!vma) | |
84d96d89 | 737 | goto out; |
1da177e4 | 738 | |
05b74384 | 739 | /* Here start < (end|vma->vm_end). */ |
1da177e4 LT |
740 | if (start < vma->vm_start) { |
741 | unmapped_error = -ENOMEM; | |
742 | start = vma->vm_start; | |
05b74384 | 743 | if (start >= end) |
84d96d89 | 744 | goto out; |
1da177e4 LT |
745 | } |
746 | ||
05b74384 PM |
747 | /* Here vma->vm_start <= start < (end|vma->vm_end) */ |
748 | tmp = vma->vm_end; | |
749 | if (end < tmp) | |
750 | tmp = end; | |
1da177e4 | 751 | |
05b74384 PM |
752 | /* Here vma->vm_start <= start < tmp <= (end|vma->vm_end). */ |
753 | error = madvise_vma(vma, &prev, start, tmp, behavior); | |
1da177e4 | 754 | if (error) |
84d96d89 | 755 | goto out; |
05b74384 | 756 | start = tmp; |
90ed52eb | 757 | if (prev && start < prev->vm_end) |
05b74384 PM |
758 | start = prev->vm_end; |
759 | error = unmapped_error; | |
760 | if (start >= end) | |
84d96d89 | 761 | goto out; |
90ed52eb HD |
762 | if (prev) |
763 | vma = prev->vm_next; | |
764 | else /* madvise_remove dropped mmap_sem */ | |
765 | vma = find_vma(current->mm, start); | |
1da177e4 | 766 | } |
1da177e4 | 767 | out: |
84d96d89 | 768 | blk_finish_plug(&plug); |
f7977793 | 769 | if (write) |
0a27a14a NP |
770 | up_write(¤t->mm->mmap_sem); |
771 | else | |
772 | up_read(¤t->mm->mmap_sem); | |
773 | ||
1da177e4 LT |
774 | return error; |
775 | } |