Commit | Line | Data |
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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 MK |
29 | #include <linux/mmu_notifier.h> |
30 | ||
31 | #include <asm/tlb.h> | |
1da177e4 | 32 | |
23519073 KS |
33 | #include "internal.h" |
34 | ||
d616d512 MK |
35 | struct madvise_walk_private { |
36 | struct mmu_gather *tlb; | |
37 | bool pageout; | |
38 | }; | |
39 | ||
0a27a14a NP |
40 | /* |
41 | * Any behaviour which results in changes to the vma->vm_flags needs to | |
42 | * take mmap_sem for writing. Others, which simply traverse vmas, need | |
43 | * to only take it for reading. | |
44 | */ | |
45 | static int madvise_need_mmap_write(int behavior) | |
46 | { | |
47 | switch (behavior) { | |
48 | case MADV_REMOVE: | |
49 | case MADV_WILLNEED: | |
50 | case MADV_DONTNEED: | |
9c276cc6 | 51 | case MADV_COLD: |
1a4e58cc | 52 | case MADV_PAGEOUT: |
854e9ed0 | 53 | case MADV_FREE: |
0a27a14a NP |
54 | return 0; |
55 | default: | |
56 | /* be safe, default to 1. list exceptions explicitly */ | |
57 | return 1; | |
58 | } | |
59 | } | |
60 | ||
1da177e4 LT |
61 | /* |
62 | * We can potentially split a vm area into separate | |
63 | * areas, each area with its own behavior. | |
64 | */ | |
ec9bed9d | 65 | static long madvise_behavior(struct vm_area_struct *vma, |
05b74384 PM |
66 | struct vm_area_struct **prev, |
67 | unsigned long start, unsigned long end, int behavior) | |
1da177e4 | 68 | { |
ec9bed9d | 69 | struct mm_struct *mm = vma->vm_mm; |
1da177e4 | 70 | int error = 0; |
05b74384 | 71 | pgoff_t pgoff; |
3866ea90 | 72 | unsigned long new_flags = vma->vm_flags; |
e798c6e8 PM |
73 | |
74 | switch (behavior) { | |
f8225661 MT |
75 | case MADV_NORMAL: |
76 | new_flags = new_flags & ~VM_RAND_READ & ~VM_SEQ_READ; | |
77 | break; | |
e798c6e8 | 78 | case MADV_SEQUENTIAL: |
f8225661 | 79 | new_flags = (new_flags & ~VM_RAND_READ) | VM_SEQ_READ; |
e798c6e8 PM |
80 | break; |
81 | case MADV_RANDOM: | |
f8225661 | 82 | new_flags = (new_flags & ~VM_SEQ_READ) | VM_RAND_READ; |
e798c6e8 | 83 | break; |
f8225661 MT |
84 | case MADV_DONTFORK: |
85 | new_flags |= VM_DONTCOPY; | |
86 | break; | |
87 | case MADV_DOFORK: | |
3866ea90 HD |
88 | if (vma->vm_flags & VM_IO) { |
89 | error = -EINVAL; | |
90 | goto out; | |
91 | } | |
f8225661 | 92 | new_flags &= ~VM_DONTCOPY; |
e798c6e8 | 93 | break; |
d2cd9ede RR |
94 | case MADV_WIPEONFORK: |
95 | /* MADV_WIPEONFORK is only supported on anonymous memory. */ | |
96 | if (vma->vm_file || vma->vm_flags & VM_SHARED) { | |
97 | error = -EINVAL; | |
98 | goto out; | |
99 | } | |
100 | new_flags |= VM_WIPEONFORK; | |
101 | break; | |
102 | case MADV_KEEPONFORK: | |
103 | new_flags &= ~VM_WIPEONFORK; | |
104 | break; | |
accb61fe | 105 | case MADV_DONTDUMP: |
0103bd16 | 106 | new_flags |= VM_DONTDUMP; |
accb61fe JB |
107 | break; |
108 | case MADV_DODUMP: | |
d41aa525 | 109 | if (!is_vm_hugetlb_page(vma) && new_flags & VM_SPECIAL) { |
0103bd16 KK |
110 | error = -EINVAL; |
111 | goto out; | |
112 | } | |
113 | new_flags &= ~VM_DONTDUMP; | |
accb61fe | 114 | break; |
f8af4da3 HD |
115 | case MADV_MERGEABLE: |
116 | case MADV_UNMERGEABLE: | |
117 | error = ksm_madvise(vma, start, end, behavior, &new_flags); | |
f3bc0dba MR |
118 | if (error) |
119 | goto out_convert_errno; | |
f8af4da3 | 120 | break; |
0af4e98b | 121 | case MADV_HUGEPAGE: |
a664b2d8 | 122 | case MADV_NOHUGEPAGE: |
60ab3244 | 123 | error = hugepage_madvise(vma, &new_flags, behavior); |
f3bc0dba MR |
124 | if (error) |
125 | goto out_convert_errno; | |
0af4e98b | 126 | break; |
e798c6e8 PM |
127 | } |
128 | ||
05b74384 PM |
129 | if (new_flags == vma->vm_flags) { |
130 | *prev = vma; | |
836d5ffd | 131 | goto out; |
05b74384 PM |
132 | } |
133 | ||
134 | pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); | |
135 | *prev = vma_merge(mm, *prev, start, end, new_flags, vma->anon_vma, | |
19a809af AA |
136 | vma->vm_file, pgoff, vma_policy(vma), |
137 | vma->vm_userfaultfd_ctx); | |
05b74384 PM |
138 | if (*prev) { |
139 | vma = *prev; | |
140 | goto success; | |
141 | } | |
142 | ||
143 | *prev = vma; | |
1da177e4 LT |
144 | |
145 | if (start != vma->vm_start) { | |
def5efe0 DR |
146 | if (unlikely(mm->map_count >= sysctl_max_map_count)) { |
147 | error = -ENOMEM; | |
1da177e4 | 148 | goto out; |
def5efe0 DR |
149 | } |
150 | error = __split_vma(mm, vma, start, 1); | |
f3bc0dba MR |
151 | if (error) |
152 | goto out_convert_errno; | |
1da177e4 LT |
153 | } |
154 | ||
155 | if (end != vma->vm_end) { | |
def5efe0 DR |
156 | if (unlikely(mm->map_count >= sysctl_max_map_count)) { |
157 | error = -ENOMEM; | |
1da177e4 | 158 | goto out; |
def5efe0 DR |
159 | } |
160 | error = __split_vma(mm, vma, end, 0); | |
f3bc0dba MR |
161 | if (error) |
162 | goto out_convert_errno; | |
1da177e4 LT |
163 | } |
164 | ||
836d5ffd | 165 | success: |
1da177e4 LT |
166 | /* |
167 | * vm_flags is protected by the mmap_sem held in write mode. | |
168 | */ | |
e798c6e8 | 169 | vma->vm_flags = new_flags; |
f3bc0dba MR |
170 | |
171 | out_convert_errno: | |
172 | /* | |
173 | * madvise() returns EAGAIN if kernel resources, such as | |
174 | * slab, are temporarily unavailable. | |
175 | */ | |
176 | if (error == -ENOMEM) | |
177 | error = -EAGAIN; | |
1da177e4 | 178 | out: |
1da177e4 LT |
179 | return error; |
180 | } | |
181 | ||
1998cc04 SL |
182 | #ifdef CONFIG_SWAP |
183 | static int swapin_walk_pmd_entry(pmd_t *pmd, unsigned long start, | |
184 | unsigned long end, struct mm_walk *walk) | |
185 | { | |
186 | pte_t *orig_pte; | |
187 | struct vm_area_struct *vma = walk->private; | |
188 | unsigned long index; | |
189 | ||
190 | if (pmd_none_or_trans_huge_or_clear_bad(pmd)) | |
191 | return 0; | |
192 | ||
193 | for (index = start; index != end; index += PAGE_SIZE) { | |
194 | pte_t pte; | |
195 | swp_entry_t entry; | |
196 | struct page *page; | |
197 | spinlock_t *ptl; | |
198 | ||
199 | orig_pte = pte_offset_map_lock(vma->vm_mm, pmd, start, &ptl); | |
200 | pte = *(orig_pte + ((index - start) / PAGE_SIZE)); | |
201 | pte_unmap_unlock(orig_pte, ptl); | |
202 | ||
0661a336 | 203 | if (pte_present(pte) || pte_none(pte)) |
1998cc04 SL |
204 | continue; |
205 | entry = pte_to_swp_entry(pte); | |
206 | if (unlikely(non_swap_entry(entry))) | |
207 | continue; | |
208 | ||
209 | page = read_swap_cache_async(entry, GFP_HIGHUSER_MOVABLE, | |
23955622 | 210 | vma, index, false); |
1998cc04 | 211 | if (page) |
09cbfeaf | 212 | put_page(page); |
1998cc04 SL |
213 | } |
214 | ||
215 | return 0; | |
216 | } | |
217 | ||
7b86ac33 CH |
218 | static const struct mm_walk_ops swapin_walk_ops = { |
219 | .pmd_entry = swapin_walk_pmd_entry, | |
220 | }; | |
1998cc04 SL |
221 | |
222 | static void force_shm_swapin_readahead(struct vm_area_struct *vma, | |
223 | unsigned long start, unsigned long end, | |
224 | struct address_space *mapping) | |
225 | { | |
226 | pgoff_t index; | |
227 | struct page *page; | |
228 | swp_entry_t swap; | |
229 | ||
230 | for (; start < end; start += PAGE_SIZE) { | |
231 | index = ((start - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; | |
232 | ||
55231e5c | 233 | page = find_get_entry(mapping, index); |
3159f943 | 234 | if (!xa_is_value(page)) { |
1998cc04 | 235 | if (page) |
09cbfeaf | 236 | put_page(page); |
1998cc04 SL |
237 | continue; |
238 | } | |
239 | swap = radix_to_swp_entry(page); | |
240 | page = read_swap_cache_async(swap, GFP_HIGHUSER_MOVABLE, | |
23955622 | 241 | NULL, 0, false); |
1998cc04 | 242 | if (page) |
09cbfeaf | 243 | put_page(page); |
1998cc04 SL |
244 | } |
245 | ||
246 | lru_add_drain(); /* Push any new pages onto the LRU now */ | |
247 | } | |
248 | #endif /* CONFIG_SWAP */ | |
249 | ||
1da177e4 LT |
250 | /* |
251 | * Schedule all required I/O operations. Do not wait for completion. | |
252 | */ | |
ec9bed9d VC |
253 | static long madvise_willneed(struct vm_area_struct *vma, |
254 | struct vm_area_struct **prev, | |
1da177e4 LT |
255 | unsigned long start, unsigned long end) |
256 | { | |
257 | struct file *file = vma->vm_file; | |
692fe624 | 258 | loff_t offset; |
1da177e4 | 259 | |
6ea8d958 | 260 | *prev = vma; |
1998cc04 | 261 | #ifdef CONFIG_SWAP |
97b713ba | 262 | if (!file) { |
7b86ac33 CH |
263 | walk_page_range(vma->vm_mm, start, end, &swapin_walk_ops, vma); |
264 | lru_add_drain(); /* Push any new pages onto the LRU now */ | |
1998cc04 SL |
265 | return 0; |
266 | } | |
1998cc04 | 267 | |
97b713ba | 268 | if (shmem_mapping(file->f_mapping)) { |
97b713ba CH |
269 | force_shm_swapin_readahead(vma, start, end, |
270 | file->f_mapping); | |
271 | return 0; | |
272 | } | |
273 | #else | |
1bef4003 S |
274 | if (!file) |
275 | return -EBADF; | |
97b713ba | 276 | #endif |
1bef4003 | 277 | |
e748dcd0 | 278 | if (IS_DAX(file_inode(file))) { |
fe77ba6f CO |
279 | /* no bad return value, but ignore advice */ |
280 | return 0; | |
281 | } | |
282 | ||
692fe624 JK |
283 | /* |
284 | * Filesystem's fadvise may need to take various locks. We need to | |
285 | * explicitly grab a reference because the vma (and hence the | |
286 | * vma's reference to the file) can go away as soon as we drop | |
287 | * mmap_sem. | |
288 | */ | |
289 | *prev = NULL; /* tell sys_madvise we drop mmap_sem */ | |
290 | get_file(file); | |
291 | up_read(¤t->mm->mmap_sem); | |
292 | offset = (loff_t)(start - vma->vm_start) | |
293 | + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); | |
294 | vfs_fadvise(file, offset, end - start, POSIX_FADV_WILLNEED); | |
295 | fput(file); | |
296 | down_read(¤t->mm->mmap_sem); | |
1da177e4 LT |
297 | return 0; |
298 | } | |
299 | ||
d616d512 MK |
300 | static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, |
301 | unsigned long addr, unsigned long end, | |
302 | struct mm_walk *walk) | |
9c276cc6 | 303 | { |
d616d512 MK |
304 | struct madvise_walk_private *private = walk->private; |
305 | struct mmu_gather *tlb = private->tlb; | |
306 | bool pageout = private->pageout; | |
9c276cc6 MK |
307 | struct mm_struct *mm = tlb->mm; |
308 | struct vm_area_struct *vma = walk->vma; | |
309 | pte_t *orig_pte, *pte, ptent; | |
310 | spinlock_t *ptl; | |
d616d512 MK |
311 | struct page *page = NULL; |
312 | LIST_HEAD(page_list); | |
313 | ||
314 | if (fatal_signal_pending(current)) | |
315 | return -EINTR; | |
9c276cc6 MK |
316 | |
317 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE | |
318 | if (pmd_trans_huge(*pmd)) { | |
319 | pmd_t orig_pmd; | |
320 | unsigned long next = pmd_addr_end(addr, end); | |
321 | ||
322 | tlb_change_page_size(tlb, HPAGE_PMD_SIZE); | |
323 | ptl = pmd_trans_huge_lock(pmd, vma); | |
324 | if (!ptl) | |
325 | return 0; | |
326 | ||
327 | orig_pmd = *pmd; | |
328 | if (is_huge_zero_pmd(orig_pmd)) | |
329 | goto huge_unlock; | |
330 | ||
331 | if (unlikely(!pmd_present(orig_pmd))) { | |
332 | VM_BUG_ON(thp_migration_supported() && | |
333 | !is_pmd_migration_entry(orig_pmd)); | |
334 | goto huge_unlock; | |
335 | } | |
336 | ||
337 | page = pmd_page(orig_pmd); | |
338 | if (next - addr != HPAGE_PMD_SIZE) { | |
339 | int err; | |
340 | ||
341 | if (page_mapcount(page) != 1) | |
342 | goto huge_unlock; | |
343 | ||
344 | get_page(page); | |
345 | spin_unlock(ptl); | |
346 | lock_page(page); | |
347 | err = split_huge_page(page); | |
348 | unlock_page(page); | |
349 | put_page(page); | |
350 | if (!err) | |
351 | goto regular_page; | |
352 | return 0; | |
353 | } | |
354 | ||
355 | if (pmd_young(orig_pmd)) { | |
356 | pmdp_invalidate(vma, addr, pmd); | |
357 | orig_pmd = pmd_mkold(orig_pmd); | |
358 | ||
359 | set_pmd_at(mm, addr, pmd, orig_pmd); | |
360 | tlb_remove_pmd_tlb_entry(tlb, pmd, addr); | |
361 | } | |
362 | ||
d616d512 | 363 | ClearPageReferenced(page); |
9c276cc6 | 364 | test_and_clear_page_young(page); |
d616d512 MK |
365 | if (pageout) { |
366 | if (!isolate_lru_page(page)) | |
367 | list_add(&page->lru, &page_list); | |
368 | } else | |
369 | deactivate_page(page); | |
9c276cc6 MK |
370 | huge_unlock: |
371 | spin_unlock(ptl); | |
d616d512 MK |
372 | if (pageout) |
373 | reclaim_pages(&page_list); | |
9c276cc6 MK |
374 | return 0; |
375 | } | |
376 | ||
377 | if (pmd_trans_unstable(pmd)) | |
378 | return 0; | |
379 | regular_page: | |
380 | #endif | |
381 | tlb_change_page_size(tlb, PAGE_SIZE); | |
382 | orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
383 | flush_tlb_batched_pending(mm); | |
384 | arch_enter_lazy_mmu_mode(); | |
385 | for (; addr < end; pte++, addr += PAGE_SIZE) { | |
386 | ptent = *pte; | |
387 | ||
388 | if (pte_none(ptent)) | |
389 | continue; | |
390 | ||
391 | if (!pte_present(ptent)) | |
392 | continue; | |
393 | ||
394 | page = vm_normal_page(vma, addr, ptent); | |
395 | if (!page) | |
396 | continue; | |
397 | ||
398 | /* | |
399 | * Creating a THP page is expensive so split it only if we | |
400 | * are sure it's worth. Split it if we are only owner. | |
401 | */ | |
402 | if (PageTransCompound(page)) { | |
403 | if (page_mapcount(page) != 1) | |
404 | break; | |
405 | get_page(page); | |
406 | if (!trylock_page(page)) { | |
407 | put_page(page); | |
408 | break; | |
409 | } | |
410 | pte_unmap_unlock(orig_pte, ptl); | |
411 | if (split_huge_page(page)) { | |
412 | unlock_page(page); | |
413 | put_page(page); | |
414 | pte_offset_map_lock(mm, pmd, addr, &ptl); | |
415 | break; | |
416 | } | |
417 | unlock_page(page); | |
418 | put_page(page); | |
419 | pte = pte_offset_map_lock(mm, pmd, addr, &ptl); | |
420 | pte--; | |
421 | addr -= PAGE_SIZE; | |
422 | continue; | |
423 | } | |
424 | ||
425 | VM_BUG_ON_PAGE(PageTransCompound(page), page); | |
426 | ||
427 | if (pte_young(ptent)) { | |
428 | ptent = ptep_get_and_clear_full(mm, addr, pte, | |
429 | tlb->fullmm); | |
430 | ptent = pte_mkold(ptent); | |
431 | set_pte_at(mm, addr, pte, ptent); | |
432 | tlb_remove_tlb_entry(tlb, pte, addr); | |
433 | } | |
434 | ||
435 | /* | |
436 | * We are deactivating a page for accelerating reclaiming. | |
437 | * VM couldn't reclaim the page unless we clear PG_young. | |
438 | * As a side effect, it makes confuse idle-page tracking | |
439 | * because they will miss recent referenced history. | |
440 | */ | |
d616d512 | 441 | ClearPageReferenced(page); |
9c276cc6 | 442 | test_and_clear_page_young(page); |
d616d512 MK |
443 | if (pageout) { |
444 | if (!isolate_lru_page(page)) | |
445 | list_add(&page->lru, &page_list); | |
446 | } else | |
447 | deactivate_page(page); | |
9c276cc6 MK |
448 | } |
449 | ||
450 | arch_leave_lazy_mmu_mode(); | |
451 | pte_unmap_unlock(orig_pte, ptl); | |
d616d512 MK |
452 | if (pageout) |
453 | reclaim_pages(&page_list); | |
9c276cc6 MK |
454 | cond_resched(); |
455 | ||
456 | return 0; | |
457 | } | |
458 | ||
459 | static const struct mm_walk_ops cold_walk_ops = { | |
d616d512 | 460 | .pmd_entry = madvise_cold_or_pageout_pte_range, |
9c276cc6 MK |
461 | }; |
462 | ||
463 | static void madvise_cold_page_range(struct mmu_gather *tlb, | |
464 | struct vm_area_struct *vma, | |
465 | unsigned long addr, unsigned long end) | |
466 | { | |
d616d512 MK |
467 | struct madvise_walk_private walk_private = { |
468 | .pageout = false, | |
469 | .tlb = tlb, | |
470 | }; | |
471 | ||
9c276cc6 | 472 | tlb_start_vma(tlb, vma); |
d616d512 | 473 | walk_page_range(vma->vm_mm, addr, end, &cold_walk_ops, &walk_private); |
9c276cc6 MK |
474 | tlb_end_vma(tlb, vma); |
475 | } | |
476 | ||
477 | static long madvise_cold(struct vm_area_struct *vma, | |
478 | struct vm_area_struct **prev, | |
479 | unsigned long start_addr, unsigned long end_addr) | |
480 | { | |
481 | struct mm_struct *mm = vma->vm_mm; | |
482 | struct mmu_gather tlb; | |
483 | ||
484 | *prev = vma; | |
485 | if (!can_madv_lru_vma(vma)) | |
486 | return -EINVAL; | |
487 | ||
488 | lru_add_drain(); | |
489 | tlb_gather_mmu(&tlb, mm, start_addr, end_addr); | |
490 | madvise_cold_page_range(&tlb, vma, start_addr, end_addr); | |
491 | tlb_finish_mmu(&tlb, start_addr, end_addr); | |
492 | ||
493 | return 0; | |
494 | } | |
495 | ||
1a4e58cc MK |
496 | static void madvise_pageout_page_range(struct mmu_gather *tlb, |
497 | struct vm_area_struct *vma, | |
498 | unsigned long addr, unsigned long end) | |
499 | { | |
d616d512 MK |
500 | struct madvise_walk_private walk_private = { |
501 | .pageout = true, | |
502 | .tlb = tlb, | |
503 | }; | |
504 | ||
1a4e58cc | 505 | tlb_start_vma(tlb, vma); |
d616d512 | 506 | walk_page_range(vma->vm_mm, addr, end, &cold_walk_ops, &walk_private); |
1a4e58cc MK |
507 | tlb_end_vma(tlb, vma); |
508 | } | |
509 | ||
510 | static inline bool can_do_pageout(struct vm_area_struct *vma) | |
511 | { | |
512 | if (vma_is_anonymous(vma)) | |
513 | return true; | |
514 | if (!vma->vm_file) | |
515 | return false; | |
516 | /* | |
517 | * paging out pagecache only for non-anonymous mappings that correspond | |
518 | * to the files the calling process could (if tried) open for writing; | |
519 | * otherwise we'd be including shared non-exclusive mappings, which | |
520 | * opens a side channel. | |
521 | */ | |
522 | return inode_owner_or_capable(file_inode(vma->vm_file)) || | |
523 | inode_permission(file_inode(vma->vm_file), MAY_WRITE) == 0; | |
524 | } | |
525 | ||
526 | static long madvise_pageout(struct vm_area_struct *vma, | |
527 | struct vm_area_struct **prev, | |
528 | unsigned long start_addr, unsigned long end_addr) | |
529 | { | |
530 | struct mm_struct *mm = vma->vm_mm; | |
531 | struct mmu_gather tlb; | |
532 | ||
533 | *prev = vma; | |
534 | if (!can_madv_lru_vma(vma)) | |
535 | return -EINVAL; | |
536 | ||
537 | if (!can_do_pageout(vma)) | |
538 | return 0; | |
539 | ||
540 | lru_add_drain(); | |
541 | tlb_gather_mmu(&tlb, mm, start_addr, end_addr); | |
542 | madvise_pageout_page_range(&tlb, vma, start_addr, end_addr); | |
543 | tlb_finish_mmu(&tlb, start_addr, end_addr); | |
544 | ||
545 | return 0; | |
546 | } | |
547 | ||
854e9ed0 MK |
548 | static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr, |
549 | unsigned long end, struct mm_walk *walk) | |
550 | ||
551 | { | |
552 | struct mmu_gather *tlb = walk->private; | |
553 | struct mm_struct *mm = tlb->mm; | |
554 | struct vm_area_struct *vma = walk->vma; | |
555 | spinlock_t *ptl; | |
556 | pte_t *orig_pte, *pte, ptent; | |
557 | struct page *page; | |
64b42bc1 | 558 | int nr_swap = 0; |
b8d3c4c3 MK |
559 | unsigned long next; |
560 | ||
561 | next = pmd_addr_end(addr, end); | |
562 | if (pmd_trans_huge(*pmd)) | |
563 | if (madvise_free_huge_pmd(tlb, vma, pmd, addr, next)) | |
564 | goto next; | |
854e9ed0 | 565 | |
854e9ed0 MK |
566 | if (pmd_trans_unstable(pmd)) |
567 | return 0; | |
568 | ||
ed6a7935 | 569 | tlb_change_page_size(tlb, PAGE_SIZE); |
854e9ed0 | 570 | orig_pte = pte = pte_offset_map_lock(mm, pmd, addr, &ptl); |
3ea27719 | 571 | flush_tlb_batched_pending(mm); |
854e9ed0 MK |
572 | arch_enter_lazy_mmu_mode(); |
573 | for (; addr != end; pte++, addr += PAGE_SIZE) { | |
574 | ptent = *pte; | |
575 | ||
64b42bc1 | 576 | if (pte_none(ptent)) |
854e9ed0 | 577 | continue; |
64b42bc1 MK |
578 | /* |
579 | * If the pte has swp_entry, just clear page table to | |
580 | * prevent swap-in which is more expensive rather than | |
581 | * (page allocation + zeroing). | |
582 | */ | |
583 | if (!pte_present(ptent)) { | |
584 | swp_entry_t entry; | |
585 | ||
586 | entry = pte_to_swp_entry(ptent); | |
587 | if (non_swap_entry(entry)) | |
588 | continue; | |
589 | nr_swap--; | |
590 | free_swap_and_cache(entry); | |
591 | pte_clear_not_present_full(mm, addr, pte, tlb->fullmm); | |
592 | continue; | |
593 | } | |
854e9ed0 | 594 | |
25b2995a | 595 | page = vm_normal_page(vma, addr, ptent); |
854e9ed0 MK |
596 | if (!page) |
597 | continue; | |
598 | ||
599 | /* | |
600 | * If pmd isn't transhuge but the page is THP and | |
601 | * is owned by only this process, split it and | |
602 | * deactivate all pages. | |
603 | */ | |
604 | if (PageTransCompound(page)) { | |
605 | if (page_mapcount(page) != 1) | |
606 | goto out; | |
607 | get_page(page); | |
608 | if (!trylock_page(page)) { | |
609 | put_page(page); | |
610 | goto out; | |
611 | } | |
612 | pte_unmap_unlock(orig_pte, ptl); | |
613 | if (split_huge_page(page)) { | |
614 | unlock_page(page); | |
615 | put_page(page); | |
616 | pte_offset_map_lock(mm, pmd, addr, &ptl); | |
617 | goto out; | |
618 | } | |
854e9ed0 | 619 | unlock_page(page); |
263630e8 | 620 | put_page(page); |
854e9ed0 MK |
621 | pte = pte_offset_map_lock(mm, pmd, addr, &ptl); |
622 | pte--; | |
623 | addr -= PAGE_SIZE; | |
624 | continue; | |
625 | } | |
626 | ||
627 | VM_BUG_ON_PAGE(PageTransCompound(page), page); | |
628 | ||
629 | if (PageSwapCache(page) || PageDirty(page)) { | |
630 | if (!trylock_page(page)) | |
631 | continue; | |
632 | /* | |
633 | * If page is shared with others, we couldn't clear | |
634 | * PG_dirty of the page. | |
635 | */ | |
636 | if (page_mapcount(page) != 1) { | |
637 | unlock_page(page); | |
638 | continue; | |
639 | } | |
640 | ||
641 | if (PageSwapCache(page) && !try_to_free_swap(page)) { | |
642 | unlock_page(page); | |
643 | continue; | |
644 | } | |
645 | ||
646 | ClearPageDirty(page); | |
647 | unlock_page(page); | |
648 | } | |
649 | ||
650 | if (pte_young(ptent) || pte_dirty(ptent)) { | |
651 | /* | |
652 | * Some of architecture(ex, PPC) don't update TLB | |
653 | * with set_pte_at and tlb_remove_tlb_entry so for | |
654 | * the portability, remap the pte with old|clean | |
655 | * after pte clearing. | |
656 | */ | |
657 | ptent = ptep_get_and_clear_full(mm, addr, pte, | |
658 | tlb->fullmm); | |
659 | ||
660 | ptent = pte_mkold(ptent); | |
661 | ptent = pte_mkclean(ptent); | |
662 | set_pte_at(mm, addr, pte, ptent); | |
663 | tlb_remove_tlb_entry(tlb, pte, addr); | |
664 | } | |
802a3a92 | 665 | mark_page_lazyfree(page); |
854e9ed0 MK |
666 | } |
667 | out: | |
64b42bc1 MK |
668 | if (nr_swap) { |
669 | if (current->mm == mm) | |
670 | sync_mm_rss(mm); | |
671 | ||
672 | add_mm_counter(mm, MM_SWAPENTS, nr_swap); | |
673 | } | |
854e9ed0 MK |
674 | arch_leave_lazy_mmu_mode(); |
675 | pte_unmap_unlock(orig_pte, ptl); | |
676 | cond_resched(); | |
b8d3c4c3 | 677 | next: |
854e9ed0 MK |
678 | return 0; |
679 | } | |
680 | ||
7b86ac33 CH |
681 | static const struct mm_walk_ops madvise_free_walk_ops = { |
682 | .pmd_entry = madvise_free_pte_range, | |
683 | }; | |
854e9ed0 MK |
684 | |
685 | static int madvise_free_single_vma(struct vm_area_struct *vma, | |
686 | unsigned long start_addr, unsigned long end_addr) | |
687 | { | |
854e9ed0 | 688 | struct mm_struct *mm = vma->vm_mm; |
ac46d4f3 | 689 | struct mmu_notifier_range range; |
854e9ed0 MK |
690 | struct mmu_gather tlb; |
691 | ||
854e9ed0 MK |
692 | /* MADV_FREE works for only anon vma at the moment */ |
693 | if (!vma_is_anonymous(vma)) | |
694 | return -EINVAL; | |
695 | ||
ac46d4f3 JG |
696 | range.start = max(vma->vm_start, start_addr); |
697 | if (range.start >= vma->vm_end) | |
854e9ed0 | 698 | return -EINVAL; |
ac46d4f3 JG |
699 | range.end = min(vma->vm_end, end_addr); |
700 | if (range.end <= vma->vm_start) | |
854e9ed0 | 701 | return -EINVAL; |
7269f999 | 702 | mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, |
6f4f13e8 | 703 | range.start, range.end); |
854e9ed0 MK |
704 | |
705 | lru_add_drain(); | |
ac46d4f3 | 706 | tlb_gather_mmu(&tlb, mm, range.start, range.end); |
854e9ed0 MK |
707 | update_hiwater_rss(mm); |
708 | ||
ac46d4f3 | 709 | mmu_notifier_invalidate_range_start(&range); |
7b86ac33 CH |
710 | tlb_start_vma(&tlb, vma); |
711 | walk_page_range(vma->vm_mm, range.start, range.end, | |
712 | &madvise_free_walk_ops, &tlb); | |
713 | tlb_end_vma(&tlb, vma); | |
ac46d4f3 JG |
714 | mmu_notifier_invalidate_range_end(&range); |
715 | tlb_finish_mmu(&tlb, range.start, range.end); | |
854e9ed0 MK |
716 | |
717 | return 0; | |
718 | } | |
719 | ||
1da177e4 LT |
720 | /* |
721 | * Application no longer needs these pages. If the pages are dirty, | |
722 | * it's OK to just throw them away. The app will be more careful about | |
723 | * data it wants to keep. Be sure to free swap resources too. The | |
7e6cbea3 | 724 | * zap_page_range call sets things up for shrink_active_list to actually free |
1da177e4 LT |
725 | * these pages later if no one else has touched them in the meantime, |
726 | * although we could add these pages to a global reuse list for | |
7e6cbea3 | 727 | * shrink_active_list to pick up before reclaiming other pages. |
1da177e4 LT |
728 | * |
729 | * NB: This interface discards data rather than pushes it out to swap, | |
730 | * as some implementations do. This has performance implications for | |
731 | * applications like large transactional databases which want to discard | |
732 | * pages in anonymous maps after committing to backing store the data | |
733 | * that was kept in them. There is no reason to write this data out to | |
734 | * the swap area if the application is discarding it. | |
735 | * | |
736 | * An interface that causes the system to free clean pages and flush | |
737 | * dirty pages is already available as msync(MS_INVALIDATE). | |
738 | */ | |
230ca982 MR |
739 | static long madvise_dontneed_single_vma(struct vm_area_struct *vma, |
740 | unsigned long start, unsigned long end) | |
741 | { | |
742 | zap_page_range(vma, start, end - start); | |
743 | return 0; | |
744 | } | |
745 | ||
746 | static long madvise_dontneed_free(struct vm_area_struct *vma, | |
747 | struct vm_area_struct **prev, | |
748 | unsigned long start, unsigned long end, | |
749 | int behavior) | |
1da177e4 | 750 | { |
05b74384 | 751 | *prev = vma; |
9c276cc6 | 752 | if (!can_madv_lru_vma(vma)) |
1da177e4 LT |
753 | return -EINVAL; |
754 | ||
70ccb92f AA |
755 | if (!userfaultfd_remove(vma, start, end)) { |
756 | *prev = NULL; /* mmap_sem has been dropped, prev is stale */ | |
757 | ||
758 | down_read(¤t->mm->mmap_sem); | |
759 | vma = find_vma(current->mm, start); | |
760 | if (!vma) | |
761 | return -ENOMEM; | |
762 | if (start < vma->vm_start) { | |
763 | /* | |
764 | * This "vma" under revalidation is the one | |
765 | * with the lowest vma->vm_start where start | |
766 | * is also < vma->vm_end. If start < | |
767 | * vma->vm_start it means an hole materialized | |
768 | * in the user address space within the | |
230ca982 MR |
769 | * virtual range passed to MADV_DONTNEED |
770 | * or MADV_FREE. | |
70ccb92f AA |
771 | */ |
772 | return -ENOMEM; | |
773 | } | |
9c276cc6 | 774 | if (!can_madv_lru_vma(vma)) |
70ccb92f AA |
775 | return -EINVAL; |
776 | if (end > vma->vm_end) { | |
777 | /* | |
778 | * Don't fail if end > vma->vm_end. If the old | |
779 | * vma was splitted while the mmap_sem was | |
780 | * released the effect of the concurrent | |
230ca982 | 781 | * operation may not cause madvise() to |
70ccb92f AA |
782 | * have an undefined result. There may be an |
783 | * adjacent next vma that we'll walk | |
784 | * next. userfaultfd_remove() will generate an | |
785 | * UFFD_EVENT_REMOVE repetition on the | |
786 | * end-vma->vm_end range, but the manager can | |
787 | * handle a repetition fine. | |
788 | */ | |
789 | end = vma->vm_end; | |
790 | } | |
791 | VM_WARN_ON(start >= end); | |
792 | } | |
230ca982 MR |
793 | |
794 | if (behavior == MADV_DONTNEED) | |
795 | return madvise_dontneed_single_vma(vma, start, end); | |
796 | else if (behavior == MADV_FREE) | |
797 | return madvise_free_single_vma(vma, start, end); | |
798 | else | |
799 | return -EINVAL; | |
1da177e4 LT |
800 | } |
801 | ||
f6b3ec23 BP |
802 | /* |
803 | * Application wants to free up the pages and associated backing store. | |
804 | * This is effectively punching a hole into the middle of a file. | |
f6b3ec23 BP |
805 | */ |
806 | static long madvise_remove(struct vm_area_struct *vma, | |
00e9fa2d | 807 | struct vm_area_struct **prev, |
f6b3ec23 BP |
808 | unsigned long start, unsigned long end) |
809 | { | |
3f31d075 | 810 | loff_t offset; |
90ed52eb | 811 | int error; |
9ab4233d | 812 | struct file *f; |
f6b3ec23 | 813 | |
90ed52eb | 814 | *prev = NULL; /* tell sys_madvise we drop mmap_sem */ |
00e9fa2d | 815 | |
72079ba0 | 816 | if (vma->vm_flags & VM_LOCKED) |
f6b3ec23 BP |
817 | return -EINVAL; |
818 | ||
9ab4233d AL |
819 | f = vma->vm_file; |
820 | ||
821 | if (!f || !f->f_mapping || !f->f_mapping->host) { | |
f6b3ec23 BP |
822 | return -EINVAL; |
823 | } | |
824 | ||
69cf0fac HD |
825 | if ((vma->vm_flags & (VM_SHARED|VM_WRITE)) != (VM_SHARED|VM_WRITE)) |
826 | return -EACCES; | |
827 | ||
f6b3ec23 BP |
828 | offset = (loff_t)(start - vma->vm_start) |
829 | + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); | |
90ed52eb | 830 | |
9ab4233d AL |
831 | /* |
832 | * Filesystem's fallocate may need to take i_mutex. We need to | |
833 | * explicitly grab a reference because the vma (and hence the | |
834 | * vma's reference to the file) can go away as soon as we drop | |
835 | * mmap_sem. | |
836 | */ | |
837 | get_file(f); | |
70ccb92f AA |
838 | if (userfaultfd_remove(vma, start, end)) { |
839 | /* mmap_sem was not released by userfaultfd_remove() */ | |
840 | up_read(¤t->mm->mmap_sem); | |
841 | } | |
72c72bdf | 842 | error = vfs_fallocate(f, |
3f31d075 HD |
843 | FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, |
844 | offset, end - start); | |
9ab4233d | 845 | fput(f); |
0a27a14a | 846 | down_read(¤t->mm->mmap_sem); |
90ed52eb | 847 | return error; |
f6b3ec23 BP |
848 | } |
849 | ||
9893e49d AK |
850 | #ifdef CONFIG_MEMORY_FAILURE |
851 | /* | |
852 | * Error injection support for memory error handling. | |
853 | */ | |
97167a76 AK |
854 | static int madvise_inject_error(int behavior, |
855 | unsigned long start, unsigned long end) | |
9893e49d | 856 | { |
97167a76 | 857 | struct page *page; |
c461ad6a | 858 | struct zone *zone; |
19bfbe22 | 859 | unsigned int order; |
97167a76 | 860 | |
9893e49d AK |
861 | if (!capable(CAP_SYS_ADMIN)) |
862 | return -EPERM; | |
97167a76 | 863 | |
19bfbe22 AM |
864 | |
865 | for (; start < end; start += PAGE_SIZE << order) { | |
23e7b5c2 | 866 | unsigned long pfn; |
325c4ef5 AM |
867 | int ret; |
868 | ||
97167a76 | 869 | ret = get_user_pages_fast(start, 1, 0, &page); |
9893e49d AK |
870 | if (ret != 1) |
871 | return ret; | |
23e7b5c2 | 872 | pfn = page_to_pfn(page); |
325c4ef5 | 873 | |
19bfbe22 AM |
874 | /* |
875 | * When soft offlining hugepages, after migrating the page | |
876 | * we dissolve it, therefore in the second loop "page" will | |
877 | * no longer be a compound page, and order will be 0. | |
878 | */ | |
879 | order = compound_order(compound_head(page)); | |
880 | ||
97167a76 AK |
881 | if (PageHWPoison(page)) { |
882 | put_page(page); | |
29b4eede WL |
883 | continue; |
884 | } | |
97167a76 AK |
885 | |
886 | if (behavior == MADV_SOFT_OFFLINE) { | |
887 | pr_info("Soft offlining pfn %#lx at process virtual address %#lx\n", | |
23e7b5c2 | 888 | pfn, start); |
97167a76 AK |
889 | |
890 | ret = soft_offline_page(page, MF_COUNT_INCREASED); | |
afcf938e | 891 | if (ret) |
8302423b | 892 | return ret; |
afcf938e AK |
893 | continue; |
894 | } | |
23e7b5c2 | 895 | |
97167a76 | 896 | pr_info("Injecting memory failure for pfn %#lx at process virtual address %#lx\n", |
23e7b5c2 | 897 | pfn, start); |
97167a76 | 898 | |
23e7b5c2 DW |
899 | /* |
900 | * Drop the page reference taken by get_user_pages_fast(). In | |
901 | * the absence of MF_COUNT_INCREASED the memory_failure() | |
902 | * routine is responsible for pinning the page to prevent it | |
903 | * from being released back to the page allocator. | |
904 | */ | |
905 | put_page(page); | |
906 | ret = memory_failure(pfn, 0); | |
23a003bf NH |
907 | if (ret) |
908 | return ret; | |
9893e49d | 909 | } |
c461ad6a MG |
910 | |
911 | /* Ensure that all poisoned pages are removed from per-cpu lists */ | |
912 | for_each_populated_zone(zone) | |
913 | drain_all_pages(zone); | |
914 | ||
325c4ef5 | 915 | return 0; |
9893e49d AK |
916 | } |
917 | #endif | |
918 | ||
165cd402 | 919 | static long |
920 | madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev, | |
921 | unsigned long start, unsigned long end, int behavior) | |
1da177e4 | 922 | { |
1da177e4 | 923 | switch (behavior) { |
f6b3ec23 | 924 | case MADV_REMOVE: |
3866ea90 | 925 | return madvise_remove(vma, prev, start, end); |
1da177e4 | 926 | case MADV_WILLNEED: |
3866ea90 | 927 | return madvise_willneed(vma, prev, start, end); |
9c276cc6 MK |
928 | case MADV_COLD: |
929 | return madvise_cold(vma, prev, start, end); | |
1a4e58cc MK |
930 | case MADV_PAGEOUT: |
931 | return madvise_pageout(vma, prev, start, end); | |
854e9ed0 | 932 | case MADV_FREE: |
1da177e4 | 933 | case MADV_DONTNEED: |
230ca982 | 934 | return madvise_dontneed_free(vma, prev, start, end, behavior); |
1da177e4 | 935 | default: |
3866ea90 | 936 | return madvise_behavior(vma, prev, start, end, behavior); |
1da177e4 | 937 | } |
1da177e4 LT |
938 | } |
939 | ||
1ecef9ed | 940 | static bool |
75927af8 NP |
941 | madvise_behavior_valid(int behavior) |
942 | { | |
943 | switch (behavior) { | |
944 | case MADV_DOFORK: | |
945 | case MADV_DONTFORK: | |
946 | case MADV_NORMAL: | |
947 | case MADV_SEQUENTIAL: | |
948 | case MADV_RANDOM: | |
949 | case MADV_REMOVE: | |
950 | case MADV_WILLNEED: | |
951 | case MADV_DONTNEED: | |
854e9ed0 | 952 | case MADV_FREE: |
9c276cc6 | 953 | case MADV_COLD: |
1a4e58cc | 954 | case MADV_PAGEOUT: |
f8af4da3 HD |
955 | #ifdef CONFIG_KSM |
956 | case MADV_MERGEABLE: | |
957 | case MADV_UNMERGEABLE: | |
0af4e98b AA |
958 | #endif |
959 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE | |
960 | case MADV_HUGEPAGE: | |
a664b2d8 | 961 | case MADV_NOHUGEPAGE: |
f8af4da3 | 962 | #endif |
accb61fe JB |
963 | case MADV_DONTDUMP: |
964 | case MADV_DODUMP: | |
d2cd9ede RR |
965 | case MADV_WIPEONFORK: |
966 | case MADV_KEEPONFORK: | |
5e451be7 AK |
967 | #ifdef CONFIG_MEMORY_FAILURE |
968 | case MADV_SOFT_OFFLINE: | |
969 | case MADV_HWPOISON: | |
970 | #endif | |
1ecef9ed | 971 | return true; |
75927af8 NP |
972 | |
973 | default: | |
1ecef9ed | 974 | return false; |
75927af8 NP |
975 | } |
976 | } | |
3866ea90 | 977 | |
1da177e4 LT |
978 | /* |
979 | * The madvise(2) system call. | |
980 | * | |
981 | * Applications can use madvise() to advise the kernel how it should | |
982 | * handle paging I/O in this VM area. The idea is to help the kernel | |
983 | * use appropriate read-ahead and caching techniques. The information | |
984 | * provided is advisory only, and can be safely disregarded by the | |
985 | * kernel without affecting the correct operation of the application. | |
986 | * | |
987 | * behavior values: | |
988 | * MADV_NORMAL - the default behavior is to read clusters. This | |
989 | * results in some read-ahead and read-behind. | |
990 | * MADV_RANDOM - the system should read the minimum amount of data | |
991 | * on any access, since it is unlikely that the appli- | |
992 | * cation will need more than what it asks for. | |
993 | * MADV_SEQUENTIAL - pages in the given range will probably be accessed | |
994 | * once, so they can be aggressively read ahead, and | |
995 | * can be freed soon after they are accessed. | |
996 | * MADV_WILLNEED - the application is notifying the system to read | |
997 | * some pages ahead. | |
998 | * MADV_DONTNEED - the application is finished with the given range, | |
999 | * so the kernel can free resources associated with it. | |
d7206a70 NH |
1000 | * MADV_FREE - the application marks pages in the given range as lazy free, |
1001 | * where actual purges are postponed until memory pressure happens. | |
f6b3ec23 BP |
1002 | * MADV_REMOVE - the application wants to free up the given range of |
1003 | * pages and associated backing store. | |
3866ea90 HD |
1004 | * MADV_DONTFORK - omit this area from child's address space when forking: |
1005 | * typically, to avoid COWing pages pinned by get_user_pages(). | |
1006 | * MADV_DOFORK - cancel MADV_DONTFORK: no longer omit this area when forking. | |
c02c3009 YS |
1007 | * MADV_WIPEONFORK - present the child process with zero-filled memory in this |
1008 | * range after a fork. | |
1009 | * MADV_KEEPONFORK - undo the effect of MADV_WIPEONFORK | |
d7206a70 NH |
1010 | * MADV_HWPOISON - trigger memory error handler as if the given memory range |
1011 | * were corrupted by unrecoverable hardware memory failure. | |
1012 | * MADV_SOFT_OFFLINE - try to soft-offline the given range of memory. | |
f8af4da3 HD |
1013 | * MADV_MERGEABLE - the application recommends that KSM try to merge pages in |
1014 | * this area with pages of identical content from other such areas. | |
1015 | * MADV_UNMERGEABLE- cancel MADV_MERGEABLE: no longer merge pages with others. | |
d7206a70 NH |
1016 | * MADV_HUGEPAGE - the application wants to back the given range by transparent |
1017 | * huge pages in the future. Existing pages might be coalesced and | |
1018 | * new pages might be allocated as THP. | |
1019 | * MADV_NOHUGEPAGE - mark the given range as not worth being backed by | |
1020 | * transparent huge pages so the existing pages will not be | |
1021 | * coalesced into THP and new pages will not be allocated as THP. | |
1022 | * MADV_DONTDUMP - the application wants to prevent pages in the given range | |
1023 | * from being included in its core dump. | |
1024 | * MADV_DODUMP - cancel MADV_DONTDUMP: no longer exclude from core dump. | |
1da177e4 LT |
1025 | * |
1026 | * return values: | |
1027 | * zero - success | |
1028 | * -EINVAL - start + len < 0, start is not page-aligned, | |
1029 | * "behavior" is not a valid value, or application | |
c02c3009 YS |
1030 | * is attempting to release locked or shared pages, |
1031 | * or the specified address range includes file, Huge TLB, | |
1032 | * MAP_SHARED or VMPFNMAP range. | |
1da177e4 LT |
1033 | * -ENOMEM - addresses in the specified range are not currently |
1034 | * mapped, or are outside the AS of the process. | |
1035 | * -EIO - an I/O error occurred while paging in data. | |
1036 | * -EBADF - map exists, but area maps something that isn't a file. | |
1037 | * -EAGAIN - a kernel resource was temporarily unavailable. | |
1038 | */ | |
3480b257 | 1039 | SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior) |
1da177e4 | 1040 | { |
05b74384 | 1041 | unsigned long end, tmp; |
ec9bed9d | 1042 | struct vm_area_struct *vma, *prev; |
1da177e4 LT |
1043 | int unmapped_error = 0; |
1044 | int error = -EINVAL; | |
f7977793 | 1045 | int write; |
1da177e4 | 1046 | size_t len; |
1998cc04 | 1047 | struct blk_plug plug; |
1da177e4 | 1048 | |
057d3389 AK |
1049 | start = untagged_addr(start); |
1050 | ||
75927af8 NP |
1051 | if (!madvise_behavior_valid(behavior)) |
1052 | return error; | |
1053 | ||
1da177e4 | 1054 | if (start & ~PAGE_MASK) |
84d96d89 | 1055 | return error; |
1da177e4 LT |
1056 | len = (len_in + ~PAGE_MASK) & PAGE_MASK; |
1057 | ||
1058 | /* Check to see whether len was rounded up from small -ve to zero */ | |
1059 | if (len_in && !len) | |
84d96d89 | 1060 | return error; |
1da177e4 LT |
1061 | |
1062 | end = start + len; | |
1063 | if (end < start) | |
84d96d89 | 1064 | return error; |
1da177e4 LT |
1065 | |
1066 | error = 0; | |
1067 | if (end == start) | |
84d96d89 RV |
1068 | return error; |
1069 | ||
5e451be7 AK |
1070 | #ifdef CONFIG_MEMORY_FAILURE |
1071 | if (behavior == MADV_HWPOISON || behavior == MADV_SOFT_OFFLINE) | |
1072 | return madvise_inject_error(behavior, start, start + len_in); | |
1073 | #endif | |
1074 | ||
84d96d89 | 1075 | write = madvise_need_mmap_write(behavior); |
dc0ef0df MH |
1076 | if (write) { |
1077 | if (down_write_killable(¤t->mm->mmap_sem)) | |
1078 | return -EINTR; | |
1079 | } else { | |
84d96d89 | 1080 | down_read(¤t->mm->mmap_sem); |
dc0ef0df | 1081 | } |
1da177e4 LT |
1082 | |
1083 | /* | |
1084 | * If the interval [start,end) covers some unmapped address | |
1085 | * ranges, just ignore them, but return -ENOMEM at the end. | |
05b74384 | 1086 | * - different from the way of handling in mlock etc. |
1da177e4 | 1087 | */ |
05b74384 | 1088 | vma = find_vma_prev(current->mm, start, &prev); |
836d5ffd HD |
1089 | if (vma && start > vma->vm_start) |
1090 | prev = vma; | |
1091 | ||
1998cc04 | 1092 | blk_start_plug(&plug); |
1da177e4 LT |
1093 | for (;;) { |
1094 | /* Still start < end. */ | |
1095 | error = -ENOMEM; | |
1096 | if (!vma) | |
84d96d89 | 1097 | goto out; |
1da177e4 | 1098 | |
05b74384 | 1099 | /* Here start < (end|vma->vm_end). */ |
1da177e4 LT |
1100 | if (start < vma->vm_start) { |
1101 | unmapped_error = -ENOMEM; | |
1102 | start = vma->vm_start; | |
05b74384 | 1103 | if (start >= end) |
84d96d89 | 1104 | goto out; |
1da177e4 LT |
1105 | } |
1106 | ||
05b74384 PM |
1107 | /* Here vma->vm_start <= start < (end|vma->vm_end) */ |
1108 | tmp = vma->vm_end; | |
1109 | if (end < tmp) | |
1110 | tmp = end; | |
1da177e4 | 1111 | |
05b74384 PM |
1112 | /* Here vma->vm_start <= start < tmp <= (end|vma->vm_end). */ |
1113 | error = madvise_vma(vma, &prev, start, tmp, behavior); | |
1da177e4 | 1114 | if (error) |
84d96d89 | 1115 | goto out; |
05b74384 | 1116 | start = tmp; |
90ed52eb | 1117 | if (prev && start < prev->vm_end) |
05b74384 PM |
1118 | start = prev->vm_end; |
1119 | error = unmapped_error; | |
1120 | if (start >= end) | |
84d96d89 | 1121 | goto out; |
90ed52eb HD |
1122 | if (prev) |
1123 | vma = prev->vm_next; | |
1124 | else /* madvise_remove dropped mmap_sem */ | |
1125 | vma = find_vma(current->mm, start); | |
1da177e4 | 1126 | } |
1da177e4 | 1127 | out: |
84d96d89 | 1128 | blk_finish_plug(&plug); |
f7977793 | 1129 | if (write) |
0a27a14a NP |
1130 | up_write(¤t->mm->mmap_sem); |
1131 | else | |
1132 | up_read(¤t->mm->mmap_sem); | |
1133 | ||
1da177e4 LT |
1134 | return error; |
1135 | } |