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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 SL |
19 | #include <linux/blkdev.h> |
20 | #include <linux/swap.h> | |
21 | #include <linux/swapops.h> | |
1da177e4 | 22 | |
0a27a14a NP |
23 | /* |
24 | * Any behaviour which results in changes to the vma->vm_flags needs to | |
25 | * take mmap_sem for writing. Others, which simply traverse vmas, need | |
26 | * to only take it for reading. | |
27 | */ | |
28 | static int madvise_need_mmap_write(int behavior) | |
29 | { | |
30 | switch (behavior) { | |
31 | case MADV_REMOVE: | |
32 | case MADV_WILLNEED: | |
33 | case MADV_DONTNEED: | |
34 | return 0; | |
35 | default: | |
36 | /* be safe, default to 1. list exceptions explicitly */ | |
37 | return 1; | |
38 | } | |
39 | } | |
40 | ||
1da177e4 LT |
41 | /* |
42 | * We can potentially split a vm area into separate | |
43 | * areas, each area with its own behavior. | |
44 | */ | |
ec9bed9d | 45 | static long madvise_behavior(struct vm_area_struct *vma, |
05b74384 PM |
46 | struct vm_area_struct **prev, |
47 | unsigned long start, unsigned long end, int behavior) | |
1da177e4 | 48 | { |
ec9bed9d | 49 | struct mm_struct *mm = vma->vm_mm; |
1da177e4 | 50 | int error = 0; |
05b74384 | 51 | pgoff_t pgoff; |
3866ea90 | 52 | unsigned long new_flags = vma->vm_flags; |
e798c6e8 PM |
53 | |
54 | switch (behavior) { | |
f8225661 MT |
55 | case MADV_NORMAL: |
56 | new_flags = new_flags & ~VM_RAND_READ & ~VM_SEQ_READ; | |
57 | break; | |
e798c6e8 | 58 | case MADV_SEQUENTIAL: |
f8225661 | 59 | new_flags = (new_flags & ~VM_RAND_READ) | VM_SEQ_READ; |
e798c6e8 PM |
60 | break; |
61 | case MADV_RANDOM: | |
f8225661 | 62 | new_flags = (new_flags & ~VM_SEQ_READ) | VM_RAND_READ; |
e798c6e8 | 63 | break; |
f8225661 MT |
64 | case MADV_DONTFORK: |
65 | new_flags |= VM_DONTCOPY; | |
66 | break; | |
67 | case MADV_DOFORK: | |
3866ea90 HD |
68 | if (vma->vm_flags & VM_IO) { |
69 | error = -EINVAL; | |
70 | goto out; | |
71 | } | |
f8225661 | 72 | new_flags &= ~VM_DONTCOPY; |
e798c6e8 | 73 | break; |
accb61fe | 74 | case MADV_DONTDUMP: |
0103bd16 | 75 | new_flags |= VM_DONTDUMP; |
accb61fe JB |
76 | break; |
77 | case MADV_DODUMP: | |
0103bd16 KK |
78 | if (new_flags & VM_SPECIAL) { |
79 | error = -EINVAL; | |
80 | goto out; | |
81 | } | |
82 | new_flags &= ~VM_DONTDUMP; | |
accb61fe | 83 | break; |
f8af4da3 HD |
84 | case MADV_MERGEABLE: |
85 | case MADV_UNMERGEABLE: | |
86 | error = ksm_madvise(vma, start, end, behavior, &new_flags); | |
87 | if (error) | |
88 | goto out; | |
89 | break; | |
0af4e98b | 90 | case MADV_HUGEPAGE: |
a664b2d8 | 91 | case MADV_NOHUGEPAGE: |
60ab3244 | 92 | error = hugepage_madvise(vma, &new_flags, behavior); |
0af4e98b AA |
93 | if (error) |
94 | goto out; | |
95 | break; | |
e798c6e8 PM |
96 | } |
97 | ||
05b74384 PM |
98 | if (new_flags == vma->vm_flags) { |
99 | *prev = vma; | |
836d5ffd | 100 | goto out; |
05b74384 PM |
101 | } |
102 | ||
103 | pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); | |
104 | *prev = vma_merge(mm, *prev, start, end, new_flags, vma->anon_vma, | |
105 | vma->vm_file, pgoff, vma_policy(vma)); | |
106 | if (*prev) { | |
107 | vma = *prev; | |
108 | goto success; | |
109 | } | |
110 | ||
111 | *prev = vma; | |
1da177e4 LT |
112 | |
113 | if (start != vma->vm_start) { | |
114 | error = split_vma(mm, vma, start, 1); | |
115 | if (error) | |
116 | goto out; | |
117 | } | |
118 | ||
119 | if (end != vma->vm_end) { | |
120 | error = split_vma(mm, vma, end, 0); | |
121 | if (error) | |
122 | goto out; | |
123 | } | |
124 | ||
836d5ffd | 125 | success: |
1da177e4 LT |
126 | /* |
127 | * vm_flags is protected by the mmap_sem held in write mode. | |
128 | */ | |
e798c6e8 | 129 | vma->vm_flags = new_flags; |
1da177e4 LT |
130 | |
131 | out: | |
132 | if (error == -ENOMEM) | |
133 | error = -EAGAIN; | |
134 | return error; | |
135 | } | |
136 | ||
1998cc04 SL |
137 | #ifdef CONFIG_SWAP |
138 | static int swapin_walk_pmd_entry(pmd_t *pmd, unsigned long start, | |
139 | unsigned long end, struct mm_walk *walk) | |
140 | { | |
141 | pte_t *orig_pte; | |
142 | struct vm_area_struct *vma = walk->private; | |
143 | unsigned long index; | |
144 | ||
145 | if (pmd_none_or_trans_huge_or_clear_bad(pmd)) | |
146 | return 0; | |
147 | ||
148 | for (index = start; index != end; index += PAGE_SIZE) { | |
149 | pte_t pte; | |
150 | swp_entry_t entry; | |
151 | struct page *page; | |
152 | spinlock_t *ptl; | |
153 | ||
154 | orig_pte = pte_offset_map_lock(vma->vm_mm, pmd, start, &ptl); | |
155 | pte = *(orig_pte + ((index - start) / PAGE_SIZE)); | |
156 | pte_unmap_unlock(orig_pte, ptl); | |
157 | ||
158 | if (pte_present(pte) || pte_none(pte) || pte_file(pte)) | |
159 | continue; | |
160 | entry = pte_to_swp_entry(pte); | |
161 | if (unlikely(non_swap_entry(entry))) | |
162 | continue; | |
163 | ||
164 | page = read_swap_cache_async(entry, GFP_HIGHUSER_MOVABLE, | |
165 | vma, index); | |
166 | if (page) | |
167 | page_cache_release(page); | |
168 | } | |
169 | ||
170 | return 0; | |
171 | } | |
172 | ||
173 | static void force_swapin_readahead(struct vm_area_struct *vma, | |
174 | unsigned long start, unsigned long end) | |
175 | { | |
176 | struct mm_walk walk = { | |
177 | .mm = vma->vm_mm, | |
178 | .pmd_entry = swapin_walk_pmd_entry, | |
179 | .private = vma, | |
180 | }; | |
181 | ||
182 | walk_page_range(start, end, &walk); | |
183 | ||
184 | lru_add_drain(); /* Push any new pages onto the LRU now */ | |
185 | } | |
186 | ||
187 | static void force_shm_swapin_readahead(struct vm_area_struct *vma, | |
188 | unsigned long start, unsigned long end, | |
189 | struct address_space *mapping) | |
190 | { | |
191 | pgoff_t index; | |
192 | struct page *page; | |
193 | swp_entry_t swap; | |
194 | ||
195 | for (; start < end; start += PAGE_SIZE) { | |
196 | index = ((start - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; | |
197 | ||
55231e5c | 198 | page = find_get_entry(mapping, index); |
1998cc04 SL |
199 | if (!radix_tree_exceptional_entry(page)) { |
200 | if (page) | |
201 | page_cache_release(page); | |
202 | continue; | |
203 | } | |
204 | swap = radix_to_swp_entry(page); | |
205 | page = read_swap_cache_async(swap, GFP_HIGHUSER_MOVABLE, | |
206 | NULL, 0); | |
207 | if (page) | |
208 | page_cache_release(page); | |
209 | } | |
210 | ||
211 | lru_add_drain(); /* Push any new pages onto the LRU now */ | |
212 | } | |
213 | #endif /* CONFIG_SWAP */ | |
214 | ||
1da177e4 LT |
215 | /* |
216 | * Schedule all required I/O operations. Do not wait for completion. | |
217 | */ | |
ec9bed9d VC |
218 | static long madvise_willneed(struct vm_area_struct *vma, |
219 | struct vm_area_struct **prev, | |
1da177e4 LT |
220 | unsigned long start, unsigned long end) |
221 | { | |
222 | struct file *file = vma->vm_file; | |
223 | ||
1998cc04 SL |
224 | #ifdef CONFIG_SWAP |
225 | if (!file || mapping_cap_swap_backed(file->f_mapping)) { | |
226 | *prev = vma; | |
227 | if (!file) | |
228 | force_swapin_readahead(vma, start, end); | |
229 | else | |
230 | force_shm_swapin_readahead(vma, start, end, | |
231 | file->f_mapping); | |
232 | return 0; | |
233 | } | |
234 | #endif | |
235 | ||
1bef4003 S |
236 | if (!file) |
237 | return -EBADF; | |
238 | ||
70688e4d | 239 | if (file->f_mapping->a_ops->get_xip_mem) { |
fe77ba6f CO |
240 | /* no bad return value, but ignore advice */ |
241 | return 0; | |
242 | } | |
243 | ||
05b74384 | 244 | *prev = vma; |
1da177e4 LT |
245 | start = ((start - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; |
246 | if (end > vma->vm_end) | |
247 | end = vma->vm_end; | |
248 | end = ((end - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; | |
249 | ||
f7e839dd | 250 | force_page_cache_readahead(file->f_mapping, file, start, end - start); |
1da177e4 LT |
251 | return 0; |
252 | } | |
253 | ||
254 | /* | |
255 | * Application no longer needs these pages. If the pages are dirty, | |
256 | * it's OK to just throw them away. The app will be more careful about | |
257 | * data it wants to keep. Be sure to free swap resources too. The | |
7e6cbea3 | 258 | * zap_page_range call sets things up for shrink_active_list to actually free |
1da177e4 LT |
259 | * these pages later if no one else has touched them in the meantime, |
260 | * although we could add these pages to a global reuse list for | |
7e6cbea3 | 261 | * shrink_active_list to pick up before reclaiming other pages. |
1da177e4 LT |
262 | * |
263 | * NB: This interface discards data rather than pushes it out to swap, | |
264 | * as some implementations do. This has performance implications for | |
265 | * applications like large transactional databases which want to discard | |
266 | * pages in anonymous maps after committing to backing store the data | |
267 | * that was kept in them. There is no reason to write this data out to | |
268 | * the swap area if the application is discarding it. | |
269 | * | |
270 | * An interface that causes the system to free clean pages and flush | |
271 | * dirty pages is already available as msync(MS_INVALIDATE). | |
272 | */ | |
ec9bed9d VC |
273 | static long madvise_dontneed(struct vm_area_struct *vma, |
274 | struct vm_area_struct **prev, | |
1da177e4 LT |
275 | unsigned long start, unsigned long end) |
276 | { | |
05b74384 | 277 | *prev = vma; |
6aab341e | 278 | if (vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP)) |
1da177e4 LT |
279 | return -EINVAL; |
280 | ||
8a5f14a2 | 281 | zap_page_range(vma, start, end - start, NULL); |
1da177e4 LT |
282 | return 0; |
283 | } | |
284 | ||
f6b3ec23 BP |
285 | /* |
286 | * Application wants to free up the pages and associated backing store. | |
287 | * This is effectively punching a hole into the middle of a file. | |
f6b3ec23 BP |
288 | */ |
289 | static long madvise_remove(struct vm_area_struct *vma, | |
00e9fa2d | 290 | struct vm_area_struct **prev, |
f6b3ec23 BP |
291 | unsigned long start, unsigned long end) |
292 | { | |
3f31d075 | 293 | loff_t offset; |
90ed52eb | 294 | int error; |
9ab4233d | 295 | struct file *f; |
f6b3ec23 | 296 | |
90ed52eb | 297 | *prev = NULL; /* tell sys_madvise we drop mmap_sem */ |
00e9fa2d | 298 | |
f6b3ec23 BP |
299 | if (vma->vm_flags & (VM_LOCKED|VM_NONLINEAR|VM_HUGETLB)) |
300 | return -EINVAL; | |
301 | ||
9ab4233d AL |
302 | f = vma->vm_file; |
303 | ||
304 | if (!f || !f->f_mapping || !f->f_mapping->host) { | |
f6b3ec23 BP |
305 | return -EINVAL; |
306 | } | |
307 | ||
69cf0fac HD |
308 | if ((vma->vm_flags & (VM_SHARED|VM_WRITE)) != (VM_SHARED|VM_WRITE)) |
309 | return -EACCES; | |
310 | ||
f6b3ec23 BP |
311 | offset = (loff_t)(start - vma->vm_start) |
312 | + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); | |
90ed52eb | 313 | |
9ab4233d AL |
314 | /* |
315 | * Filesystem's fallocate may need to take i_mutex. We need to | |
316 | * explicitly grab a reference because the vma (and hence the | |
317 | * vma's reference to the file) can go away as soon as we drop | |
318 | * mmap_sem. | |
319 | */ | |
320 | get_file(f); | |
0a27a14a | 321 | up_read(¤t->mm->mmap_sem); |
72c72bdf | 322 | error = vfs_fallocate(f, |
3f31d075 HD |
323 | FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, |
324 | offset, end - start); | |
9ab4233d | 325 | fput(f); |
0a27a14a | 326 | down_read(¤t->mm->mmap_sem); |
90ed52eb | 327 | return error; |
f6b3ec23 BP |
328 | } |
329 | ||
9893e49d AK |
330 | #ifdef CONFIG_MEMORY_FAILURE |
331 | /* | |
332 | * Error injection support for memory error handling. | |
333 | */ | |
afcf938e | 334 | static int madvise_hwpoison(int bhv, unsigned long start, unsigned long end) |
9893e49d | 335 | { |
20cb6cab | 336 | struct page *p; |
9893e49d AK |
337 | if (!capable(CAP_SYS_ADMIN)) |
338 | return -EPERM; | |
20cb6cab WL |
339 | for (; start < end; start += PAGE_SIZE << |
340 | compound_order(compound_head(p))) { | |
325c4ef5 AM |
341 | int ret; |
342 | ||
343 | ret = get_user_pages_fast(start, 1, 0, &p); | |
9893e49d AK |
344 | if (ret != 1) |
345 | return ret; | |
325c4ef5 | 346 | |
29b4eede WL |
347 | if (PageHWPoison(p)) { |
348 | put_page(p); | |
349 | continue; | |
350 | } | |
afcf938e | 351 | if (bhv == MADV_SOFT_OFFLINE) { |
b194b8cd | 352 | pr_info("Soft offlining page %#lx at %#lx\n", |
afcf938e AK |
353 | page_to_pfn(p), start); |
354 | ret = soft_offline_page(p, MF_COUNT_INCREASED); | |
355 | if (ret) | |
8302423b | 356 | return ret; |
afcf938e AK |
357 | continue; |
358 | } | |
b194b8cd | 359 | pr_info("Injecting memory failure for page %#lx at %#lx\n", |
9893e49d AK |
360 | page_to_pfn(p), start); |
361 | /* Ignore return value for now */ | |
cd42f4a3 | 362 | memory_failure(page_to_pfn(p), 0, MF_COUNT_INCREASED); |
9893e49d | 363 | } |
325c4ef5 | 364 | return 0; |
9893e49d AK |
365 | } |
366 | #endif | |
367 | ||
165cd402 | 368 | static long |
369 | madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev, | |
370 | unsigned long start, unsigned long end, int behavior) | |
1da177e4 | 371 | { |
1da177e4 | 372 | switch (behavior) { |
f6b3ec23 | 373 | case MADV_REMOVE: |
3866ea90 | 374 | return madvise_remove(vma, prev, start, end); |
1da177e4 | 375 | case MADV_WILLNEED: |
3866ea90 | 376 | return madvise_willneed(vma, prev, start, end); |
1da177e4 | 377 | case MADV_DONTNEED: |
3866ea90 | 378 | return madvise_dontneed(vma, prev, start, end); |
1da177e4 | 379 | default: |
3866ea90 | 380 | return madvise_behavior(vma, prev, start, end, behavior); |
1da177e4 | 381 | } |
1da177e4 LT |
382 | } |
383 | ||
75927af8 NP |
384 | static int |
385 | madvise_behavior_valid(int behavior) | |
386 | { | |
387 | switch (behavior) { | |
388 | case MADV_DOFORK: | |
389 | case MADV_DONTFORK: | |
390 | case MADV_NORMAL: | |
391 | case MADV_SEQUENTIAL: | |
392 | case MADV_RANDOM: | |
393 | case MADV_REMOVE: | |
394 | case MADV_WILLNEED: | |
395 | case MADV_DONTNEED: | |
f8af4da3 HD |
396 | #ifdef CONFIG_KSM |
397 | case MADV_MERGEABLE: | |
398 | case MADV_UNMERGEABLE: | |
0af4e98b AA |
399 | #endif |
400 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE | |
401 | case MADV_HUGEPAGE: | |
a664b2d8 | 402 | case MADV_NOHUGEPAGE: |
f8af4da3 | 403 | #endif |
accb61fe JB |
404 | case MADV_DONTDUMP: |
405 | case MADV_DODUMP: | |
75927af8 NP |
406 | return 1; |
407 | ||
408 | default: | |
409 | return 0; | |
410 | } | |
411 | } | |
3866ea90 | 412 | |
1da177e4 LT |
413 | /* |
414 | * The madvise(2) system call. | |
415 | * | |
416 | * Applications can use madvise() to advise the kernel how it should | |
417 | * handle paging I/O in this VM area. The idea is to help the kernel | |
418 | * use appropriate read-ahead and caching techniques. The information | |
419 | * provided is advisory only, and can be safely disregarded by the | |
420 | * kernel without affecting the correct operation of the application. | |
421 | * | |
422 | * behavior values: | |
423 | * MADV_NORMAL - the default behavior is to read clusters. This | |
424 | * results in some read-ahead and read-behind. | |
425 | * MADV_RANDOM - the system should read the minimum amount of data | |
426 | * on any access, since it is unlikely that the appli- | |
427 | * cation will need more than what it asks for. | |
428 | * MADV_SEQUENTIAL - pages in the given range will probably be accessed | |
429 | * once, so they can be aggressively read ahead, and | |
430 | * can be freed soon after they are accessed. | |
431 | * MADV_WILLNEED - the application is notifying the system to read | |
432 | * some pages ahead. | |
433 | * MADV_DONTNEED - the application is finished with the given range, | |
434 | * so the kernel can free resources associated with it. | |
f6b3ec23 BP |
435 | * MADV_REMOVE - the application wants to free up the given range of |
436 | * pages and associated backing store. | |
3866ea90 HD |
437 | * MADV_DONTFORK - omit this area from child's address space when forking: |
438 | * typically, to avoid COWing pages pinned by get_user_pages(). | |
439 | * MADV_DOFORK - cancel MADV_DONTFORK: no longer omit this area when forking. | |
f8af4da3 HD |
440 | * MADV_MERGEABLE - the application recommends that KSM try to merge pages in |
441 | * this area with pages of identical content from other such areas. | |
442 | * MADV_UNMERGEABLE- cancel MADV_MERGEABLE: no longer merge pages with others. | |
1da177e4 LT |
443 | * |
444 | * return values: | |
445 | * zero - success | |
446 | * -EINVAL - start + len < 0, start is not page-aligned, | |
447 | * "behavior" is not a valid value, or application | |
448 | * is attempting to release locked or shared pages. | |
449 | * -ENOMEM - addresses in the specified range are not currently | |
450 | * mapped, or are outside the AS of the process. | |
451 | * -EIO - an I/O error occurred while paging in data. | |
452 | * -EBADF - map exists, but area maps something that isn't a file. | |
453 | * -EAGAIN - a kernel resource was temporarily unavailable. | |
454 | */ | |
3480b257 | 455 | SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior) |
1da177e4 | 456 | { |
05b74384 | 457 | unsigned long end, tmp; |
ec9bed9d | 458 | struct vm_area_struct *vma, *prev; |
1da177e4 LT |
459 | int unmapped_error = 0; |
460 | int error = -EINVAL; | |
f7977793 | 461 | int write; |
1da177e4 | 462 | size_t len; |
1998cc04 | 463 | struct blk_plug plug; |
1da177e4 | 464 | |
9893e49d | 465 | #ifdef CONFIG_MEMORY_FAILURE |
afcf938e AK |
466 | if (behavior == MADV_HWPOISON || behavior == MADV_SOFT_OFFLINE) |
467 | return madvise_hwpoison(behavior, start, start+len_in); | |
9893e49d | 468 | #endif |
75927af8 NP |
469 | if (!madvise_behavior_valid(behavior)) |
470 | return error; | |
471 | ||
1da177e4 | 472 | if (start & ~PAGE_MASK) |
84d96d89 | 473 | return error; |
1da177e4 LT |
474 | len = (len_in + ~PAGE_MASK) & PAGE_MASK; |
475 | ||
476 | /* Check to see whether len was rounded up from small -ve to zero */ | |
477 | if (len_in && !len) | |
84d96d89 | 478 | return error; |
1da177e4 LT |
479 | |
480 | end = start + len; | |
481 | if (end < start) | |
84d96d89 | 482 | return error; |
1da177e4 LT |
483 | |
484 | error = 0; | |
485 | if (end == start) | |
84d96d89 RV |
486 | return error; |
487 | ||
488 | write = madvise_need_mmap_write(behavior); | |
489 | if (write) | |
490 | down_write(¤t->mm->mmap_sem); | |
491 | else | |
492 | down_read(¤t->mm->mmap_sem); | |
1da177e4 LT |
493 | |
494 | /* | |
495 | * If the interval [start,end) covers some unmapped address | |
496 | * ranges, just ignore them, but return -ENOMEM at the end. | |
05b74384 | 497 | * - different from the way of handling in mlock etc. |
1da177e4 | 498 | */ |
05b74384 | 499 | vma = find_vma_prev(current->mm, start, &prev); |
836d5ffd HD |
500 | if (vma && start > vma->vm_start) |
501 | prev = vma; | |
502 | ||
1998cc04 | 503 | blk_start_plug(&plug); |
1da177e4 LT |
504 | for (;;) { |
505 | /* Still start < end. */ | |
506 | error = -ENOMEM; | |
507 | if (!vma) | |
84d96d89 | 508 | goto out; |
1da177e4 | 509 | |
05b74384 | 510 | /* Here start < (end|vma->vm_end). */ |
1da177e4 LT |
511 | if (start < vma->vm_start) { |
512 | unmapped_error = -ENOMEM; | |
513 | start = vma->vm_start; | |
05b74384 | 514 | if (start >= end) |
84d96d89 | 515 | goto out; |
1da177e4 LT |
516 | } |
517 | ||
05b74384 PM |
518 | /* Here vma->vm_start <= start < (end|vma->vm_end) */ |
519 | tmp = vma->vm_end; | |
520 | if (end < tmp) | |
521 | tmp = end; | |
1da177e4 | 522 | |
05b74384 PM |
523 | /* Here vma->vm_start <= start < tmp <= (end|vma->vm_end). */ |
524 | error = madvise_vma(vma, &prev, start, tmp, behavior); | |
1da177e4 | 525 | if (error) |
84d96d89 | 526 | goto out; |
05b74384 | 527 | start = tmp; |
90ed52eb | 528 | if (prev && start < prev->vm_end) |
05b74384 PM |
529 | start = prev->vm_end; |
530 | error = unmapped_error; | |
531 | if (start >= end) | |
84d96d89 | 532 | goto out; |
90ed52eb HD |
533 | if (prev) |
534 | vma = prev->vm_next; | |
535 | else /* madvise_remove dropped mmap_sem */ | |
536 | vma = find_vma(current->mm, start); | |
1da177e4 | 537 | } |
1da177e4 | 538 | out: |
84d96d89 | 539 | blk_finish_plug(&plug); |
f7977793 | 540 | if (write) |
0a27a14a NP |
541 | up_write(¤t->mm->mmap_sem); |
542 | else | |
543 | up_read(¤t->mm->mmap_sem); | |
544 | ||
1da177e4 LT |
545 | return error; |
546 | } |