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> |
ecb8ac8b | 20 | #include <linux/sched/mm.h> |
17fca131 | 21 | #include <linux/mm_inline.h> |
9a10064f | 22 | #include <linux/string.h> |
ecb8ac8b | 23 | #include <linux/uio.h> |
f8af4da3 | 24 | #include <linux/ksm.h> |
3f31d075 | 25 | #include <linux/fs.h> |
9ab4233d | 26 | #include <linux/file.h> |
1998cc04 | 27 | #include <linux/blkdev.h> |
66114cad | 28 | #include <linux/backing-dev.h> |
a520110e | 29 | #include <linux/pagewalk.h> |
1998cc04 SL |
30 | #include <linux/swap.h> |
31 | #include <linux/swapops.h> | |
3a4f8a0b | 32 | #include <linux/shmem_fs.h> |
854e9ed0 MK |
33 | #include <linux/mmu_notifier.h> |
34 | ||
35 | #include <asm/tlb.h> | |
1da177e4 | 36 | |
23519073 KS |
37 | #include "internal.h" |
38 | ||
d616d512 MK |
39 | struct madvise_walk_private { |
40 | struct mmu_gather *tlb; | |
41 | bool pageout; | |
42 | }; | |
43 | ||
0a27a14a NP |
44 | /* |
45 | * Any behaviour which results in changes to the vma->vm_flags needs to | |
c1e8d7c6 | 46 | * take mmap_lock for writing. Others, which simply traverse vmas, need |
0a27a14a NP |
47 | * to only take it for reading. |
48 | */ | |
49 | static int madvise_need_mmap_write(int behavior) | |
50 | { | |
51 | switch (behavior) { | |
52 | case MADV_REMOVE: | |
53 | case MADV_WILLNEED: | |
54 | case MADV_DONTNEED: | |
9c276cc6 | 55 | case MADV_COLD: |
1a4e58cc | 56 | case MADV_PAGEOUT: |
854e9ed0 | 57 | case MADV_FREE: |
4ca9b385 DH |
58 | case MADV_POPULATE_READ: |
59 | case MADV_POPULATE_WRITE: | |
0a27a14a NP |
60 | return 0; |
61 | default: | |
62 | /* be safe, default to 1. list exceptions explicitly */ | |
63 | return 1; | |
64 | } | |
65 | } | |
66 | ||
9a10064f | 67 | #ifdef CONFIG_ANON_VMA_NAME |
78db3412 SB |
68 | static struct anon_vma_name *anon_vma_name_alloc(const char *name) |
69 | { | |
70 | struct anon_vma_name *anon_name; | |
71 | size_t count; | |
72 | ||
73 | /* Add 1 for NUL terminator at the end of the anon_name->name */ | |
74 | count = strlen(name) + 1; | |
75 | anon_name = kmalloc(struct_size(anon_name, name, count), GFP_KERNEL); | |
76 | if (anon_name) { | |
77 | kref_init(&anon_name->kref); | |
78 | memcpy(anon_name->name, name, count); | |
79 | } | |
80 | ||
81 | return anon_name; | |
82 | } | |
83 | ||
84 | static void vma_anon_name_free(struct kref *kref) | |
85 | { | |
86 | struct anon_vma_name *anon_name = | |
87 | container_of(kref, struct anon_vma_name, kref); | |
88 | kfree(anon_name); | |
89 | } | |
90 | ||
9a10064f CC |
91 | static inline bool has_vma_anon_name(struct vm_area_struct *vma) |
92 | { | |
93 | return !vma->vm_file && vma->anon_name; | |
94 | } | |
95 | ||
96 | const char *vma_anon_name(struct vm_area_struct *vma) | |
97 | { | |
98 | if (!has_vma_anon_name(vma)) | |
99 | return NULL; | |
100 | ||
101 | mmap_assert_locked(vma->vm_mm); | |
102 | ||
78db3412 | 103 | return vma->anon_name->name; |
9a10064f CC |
104 | } |
105 | ||
106 | void dup_vma_anon_name(struct vm_area_struct *orig_vma, | |
107 | struct vm_area_struct *new_vma) | |
108 | { | |
109 | if (!has_vma_anon_name(orig_vma)) | |
110 | return; | |
111 | ||
78db3412 SB |
112 | kref_get(&orig_vma->anon_name->kref); |
113 | new_vma->anon_name = orig_vma->anon_name; | |
9a10064f CC |
114 | } |
115 | ||
116 | void free_vma_anon_name(struct vm_area_struct *vma) | |
117 | { | |
78db3412 SB |
118 | struct anon_vma_name *anon_name; |
119 | ||
9a10064f CC |
120 | if (!has_vma_anon_name(vma)) |
121 | return; | |
122 | ||
78db3412 | 123 | anon_name = vma->anon_name; |
9a10064f | 124 | vma->anon_name = NULL; |
78db3412 | 125 | kref_put(&anon_name->kref, vma_anon_name_free); |
9a10064f CC |
126 | } |
127 | ||
128 | /* mmap_lock should be write-locked */ | |
129 | static int replace_vma_anon_name(struct vm_area_struct *vma, const char *name) | |
130 | { | |
78db3412 SB |
131 | const char *anon_name; |
132 | ||
9a10064f CC |
133 | if (!name) { |
134 | free_vma_anon_name(vma); | |
135 | return 0; | |
136 | } | |
137 | ||
78db3412 SB |
138 | anon_name = vma_anon_name(vma); |
139 | if (anon_name) { | |
9a10064f | 140 | /* Same name, nothing to do here */ |
78db3412 | 141 | if (!strcmp(name, anon_name)) |
9a10064f CC |
142 | return 0; |
143 | ||
144 | free_vma_anon_name(vma); | |
145 | } | |
78db3412 | 146 | vma->anon_name = anon_vma_name_alloc(name); |
9a10064f CC |
147 | if (!vma->anon_name) |
148 | return -ENOMEM; | |
149 | ||
150 | return 0; | |
151 | } | |
152 | #else /* CONFIG_ANON_VMA_NAME */ | |
153 | static int replace_vma_anon_name(struct vm_area_struct *vma, const char *name) | |
154 | { | |
155 | if (name) | |
156 | return -EINVAL; | |
157 | ||
158 | return 0; | |
159 | } | |
160 | #endif /* CONFIG_ANON_VMA_NAME */ | |
1da177e4 | 161 | /* |
ac1e9acc CC |
162 | * Update the vm_flags on region of a vma, splitting it or merging it as |
163 | * necessary. Must be called with mmap_sem held for writing; | |
1da177e4 | 164 | */ |
ac1e9acc CC |
165 | static int madvise_update_vma(struct vm_area_struct *vma, |
166 | struct vm_area_struct **prev, unsigned long start, | |
9a10064f CC |
167 | unsigned long end, unsigned long new_flags, |
168 | const char *name) | |
1da177e4 | 169 | { |
ec9bed9d | 170 | struct mm_struct *mm = vma->vm_mm; |
ac1e9acc | 171 | int error; |
05b74384 | 172 | pgoff_t pgoff; |
e798c6e8 | 173 | |
9a10064f | 174 | if (new_flags == vma->vm_flags && is_same_vma_anon_name(vma, name)) { |
05b74384 | 175 | *prev = vma; |
ac1e9acc | 176 | return 0; |
05b74384 PM |
177 | } |
178 | ||
179 | pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); | |
180 | *prev = vma_merge(mm, *prev, start, end, new_flags, vma->anon_vma, | |
19a809af | 181 | vma->vm_file, pgoff, vma_policy(vma), |
9a10064f | 182 | vma->vm_userfaultfd_ctx, name); |
05b74384 PM |
183 | if (*prev) { |
184 | vma = *prev; | |
185 | goto success; | |
186 | } | |
187 | ||
188 | *prev = vma; | |
1da177e4 LT |
189 | |
190 | if (start != vma->vm_start) { | |
ac1e9acc CC |
191 | if (unlikely(mm->map_count >= sysctl_max_map_count)) |
192 | return -ENOMEM; | |
def5efe0 | 193 | error = __split_vma(mm, vma, start, 1); |
f3bc0dba | 194 | if (error) |
ac1e9acc | 195 | return error; |
1da177e4 LT |
196 | } |
197 | ||
198 | if (end != vma->vm_end) { | |
ac1e9acc CC |
199 | if (unlikely(mm->map_count >= sysctl_max_map_count)) |
200 | return -ENOMEM; | |
def5efe0 | 201 | error = __split_vma(mm, vma, end, 0); |
f3bc0dba | 202 | if (error) |
ac1e9acc | 203 | return error; |
1da177e4 LT |
204 | } |
205 | ||
836d5ffd | 206 | success: |
1da177e4 | 207 | /* |
c1e8d7c6 | 208 | * vm_flags is protected by the mmap_lock held in write mode. |
1da177e4 | 209 | */ |
e798c6e8 | 210 | vma->vm_flags = new_flags; |
9a10064f CC |
211 | if (!vma->vm_file) { |
212 | error = replace_vma_anon_name(vma, name); | |
213 | if (error) | |
214 | return error; | |
215 | } | |
f3bc0dba | 216 | |
ac1e9acc | 217 | return 0; |
1da177e4 LT |
218 | } |
219 | ||
1998cc04 SL |
220 | #ifdef CONFIG_SWAP |
221 | static int swapin_walk_pmd_entry(pmd_t *pmd, unsigned long start, | |
222 | unsigned long end, struct mm_walk *walk) | |
223 | { | |
224 | pte_t *orig_pte; | |
225 | struct vm_area_struct *vma = walk->private; | |
226 | unsigned long index; | |
227 | ||
228 | if (pmd_none_or_trans_huge_or_clear_bad(pmd)) | |
229 | return 0; | |
230 | ||
231 | for (index = start; index != end; index += PAGE_SIZE) { | |
232 | pte_t pte; | |
233 | swp_entry_t entry; | |
234 | struct page *page; | |
235 | spinlock_t *ptl; | |
236 | ||
237 | orig_pte = pte_offset_map_lock(vma->vm_mm, pmd, start, &ptl); | |
238 | pte = *(orig_pte + ((index - start) / PAGE_SIZE)); | |
239 | pte_unmap_unlock(orig_pte, ptl); | |
240 | ||
0661a336 | 241 | if (pte_present(pte) || pte_none(pte)) |
1998cc04 SL |
242 | continue; |
243 | entry = pte_to_swp_entry(pte); | |
244 | if (unlikely(non_swap_entry(entry))) | |
245 | continue; | |
246 | ||
247 | page = read_swap_cache_async(entry, GFP_HIGHUSER_MOVABLE, | |
23955622 | 248 | vma, index, false); |
1998cc04 | 249 | if (page) |
09cbfeaf | 250 | put_page(page); |
1998cc04 SL |
251 | } |
252 | ||
253 | return 0; | |
254 | } | |
255 | ||
7b86ac33 CH |
256 | static const struct mm_walk_ops swapin_walk_ops = { |
257 | .pmd_entry = swapin_walk_pmd_entry, | |
258 | }; | |
1998cc04 SL |
259 | |
260 | static void force_shm_swapin_readahead(struct vm_area_struct *vma, | |
261 | unsigned long start, unsigned long end, | |
262 | struct address_space *mapping) | |
263 | { | |
e6e88712 | 264 | XA_STATE(xas, &mapping->i_pages, linear_page_index(vma, start)); |
66383800 | 265 | pgoff_t end_index = linear_page_index(vma, end + PAGE_SIZE - 1); |
1998cc04 | 266 | struct page *page; |
1998cc04 | 267 | |
e6e88712 MWO |
268 | rcu_read_lock(); |
269 | xas_for_each(&xas, page, end_index) { | |
270 | swp_entry_t swap; | |
1998cc04 | 271 | |
e6e88712 | 272 | if (!xa_is_value(page)) |
1998cc04 | 273 | continue; |
e6e88712 MWO |
274 | xas_pause(&xas); |
275 | rcu_read_unlock(); | |
276 | ||
1998cc04 SL |
277 | swap = radix_to_swp_entry(page); |
278 | page = read_swap_cache_async(swap, GFP_HIGHUSER_MOVABLE, | |
23955622 | 279 | NULL, 0, false); |
1998cc04 | 280 | if (page) |
09cbfeaf | 281 | put_page(page); |
e6e88712 MWO |
282 | |
283 | rcu_read_lock(); | |
1998cc04 | 284 | } |
e6e88712 | 285 | rcu_read_unlock(); |
1998cc04 SL |
286 | |
287 | lru_add_drain(); /* Push any new pages onto the LRU now */ | |
288 | } | |
289 | #endif /* CONFIG_SWAP */ | |
290 | ||
1da177e4 LT |
291 | /* |
292 | * Schedule all required I/O operations. Do not wait for completion. | |
293 | */ | |
ec9bed9d VC |
294 | static long madvise_willneed(struct vm_area_struct *vma, |
295 | struct vm_area_struct **prev, | |
1da177e4 LT |
296 | unsigned long start, unsigned long end) |
297 | { | |
0726b01e | 298 | struct mm_struct *mm = vma->vm_mm; |
1da177e4 | 299 | struct file *file = vma->vm_file; |
692fe624 | 300 | loff_t offset; |
1da177e4 | 301 | |
6ea8d958 | 302 | *prev = vma; |
1998cc04 | 303 | #ifdef CONFIG_SWAP |
97b713ba | 304 | if (!file) { |
7b86ac33 CH |
305 | walk_page_range(vma->vm_mm, start, end, &swapin_walk_ops, vma); |
306 | lru_add_drain(); /* Push any new pages onto the LRU now */ | |
1998cc04 SL |
307 | return 0; |
308 | } | |
1998cc04 | 309 | |
97b713ba | 310 | if (shmem_mapping(file->f_mapping)) { |
97b713ba CH |
311 | force_shm_swapin_readahead(vma, start, end, |
312 | file->f_mapping); | |
313 | return 0; | |
314 | } | |
315 | #else | |
1bef4003 S |
316 | if (!file) |
317 | return -EBADF; | |
97b713ba | 318 | #endif |
1bef4003 | 319 | |
e748dcd0 | 320 | if (IS_DAX(file_inode(file))) { |
fe77ba6f CO |
321 | /* no bad return value, but ignore advice */ |
322 | return 0; | |
323 | } | |
324 | ||
692fe624 JK |
325 | /* |
326 | * Filesystem's fadvise may need to take various locks. We need to | |
327 | * explicitly grab a reference because the vma (and hence the | |
328 | * vma's reference to the file) can go away as soon as we drop | |
c1e8d7c6 | 329 | * mmap_lock. |
692fe624 | 330 | */ |
c1e8d7c6 | 331 | *prev = NULL; /* tell sys_madvise we drop mmap_lock */ |
692fe624 | 332 | get_file(file); |
692fe624 JK |
333 | offset = (loff_t)(start - vma->vm_start) |
334 | + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); | |
0726b01e | 335 | mmap_read_unlock(mm); |
692fe624 JK |
336 | vfs_fadvise(file, offset, end - start, POSIX_FADV_WILLNEED); |
337 | fput(file); | |
0726b01e | 338 | mmap_read_lock(mm); |
1da177e4 LT |
339 | return 0; |
340 | } | |
341 | ||
d616d512 MK |
342 | static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, |
343 | unsigned long addr, unsigned long end, | |
344 | struct mm_walk *walk) | |
9c276cc6 | 345 | { |
d616d512 MK |
346 | struct madvise_walk_private *private = walk->private; |
347 | struct mmu_gather *tlb = private->tlb; | |
348 | bool pageout = private->pageout; | |
9c276cc6 MK |
349 | struct mm_struct *mm = tlb->mm; |
350 | struct vm_area_struct *vma = walk->vma; | |
351 | pte_t *orig_pte, *pte, ptent; | |
352 | spinlock_t *ptl; | |
d616d512 MK |
353 | struct page *page = NULL; |
354 | LIST_HEAD(page_list); | |
355 | ||
356 | if (fatal_signal_pending(current)) | |
357 | return -EINTR; | |
9c276cc6 MK |
358 | |
359 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE | |
360 | if (pmd_trans_huge(*pmd)) { | |
361 | pmd_t orig_pmd; | |
362 | unsigned long next = pmd_addr_end(addr, end); | |
363 | ||
364 | tlb_change_page_size(tlb, HPAGE_PMD_SIZE); | |
365 | ptl = pmd_trans_huge_lock(pmd, vma); | |
366 | if (!ptl) | |
367 | return 0; | |
368 | ||
369 | orig_pmd = *pmd; | |
370 | if (is_huge_zero_pmd(orig_pmd)) | |
371 | goto huge_unlock; | |
372 | ||
373 | if (unlikely(!pmd_present(orig_pmd))) { | |
374 | VM_BUG_ON(thp_migration_supported() && | |
375 | !is_pmd_migration_entry(orig_pmd)); | |
376 | goto huge_unlock; | |
377 | } | |
378 | ||
379 | page = pmd_page(orig_pmd); | |
12e967fd MH |
380 | |
381 | /* Do not interfere with other mappings of this page */ | |
382 | if (page_mapcount(page) != 1) | |
383 | goto huge_unlock; | |
384 | ||
9c276cc6 MK |
385 | if (next - addr != HPAGE_PMD_SIZE) { |
386 | int err; | |
387 | ||
9c276cc6 MK |
388 | get_page(page); |
389 | spin_unlock(ptl); | |
390 | lock_page(page); | |
391 | err = split_huge_page(page); | |
392 | unlock_page(page); | |
393 | put_page(page); | |
394 | if (!err) | |
395 | goto regular_page; | |
396 | return 0; | |
397 | } | |
398 | ||
399 | if (pmd_young(orig_pmd)) { | |
400 | pmdp_invalidate(vma, addr, pmd); | |
401 | orig_pmd = pmd_mkold(orig_pmd); | |
402 | ||
403 | set_pmd_at(mm, addr, pmd, orig_pmd); | |
404 | tlb_remove_pmd_tlb_entry(tlb, pmd, addr); | |
405 | } | |
406 | ||
d616d512 | 407 | ClearPageReferenced(page); |
9c276cc6 | 408 | test_and_clear_page_young(page); |
d616d512 | 409 | if (pageout) { |
82072962 | 410 | if (!isolate_lru_page(page)) { |
411 | if (PageUnevictable(page)) | |
412 | putback_lru_page(page); | |
413 | else | |
414 | list_add(&page->lru, &page_list); | |
415 | } | |
d616d512 MK |
416 | } else |
417 | deactivate_page(page); | |
9c276cc6 MK |
418 | huge_unlock: |
419 | spin_unlock(ptl); | |
d616d512 MK |
420 | if (pageout) |
421 | reclaim_pages(&page_list); | |
9c276cc6 MK |
422 | return 0; |
423 | } | |
424 | ||
ce268425 | 425 | regular_page: |
9c276cc6 MK |
426 | if (pmd_trans_unstable(pmd)) |
427 | return 0; | |
9c276cc6 MK |
428 | #endif |
429 | tlb_change_page_size(tlb, PAGE_SIZE); | |
430 | orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
431 | flush_tlb_batched_pending(mm); | |
432 | arch_enter_lazy_mmu_mode(); | |
433 | for (; addr < end; pte++, addr += PAGE_SIZE) { | |
434 | ptent = *pte; | |
435 | ||
436 | if (pte_none(ptent)) | |
437 | continue; | |
438 | ||
439 | if (!pte_present(ptent)) | |
440 | continue; | |
441 | ||
442 | page = vm_normal_page(vma, addr, ptent); | |
443 | if (!page) | |
444 | continue; | |
445 | ||
446 | /* | |
447 | * Creating a THP page is expensive so split it only if we | |
448 | * are sure it's worth. Split it if we are only owner. | |
449 | */ | |
450 | if (PageTransCompound(page)) { | |
451 | if (page_mapcount(page) != 1) | |
452 | break; | |
453 | get_page(page); | |
454 | if (!trylock_page(page)) { | |
455 | put_page(page); | |
456 | break; | |
457 | } | |
458 | pte_unmap_unlock(orig_pte, ptl); | |
459 | if (split_huge_page(page)) { | |
460 | unlock_page(page); | |
461 | put_page(page); | |
462 | pte_offset_map_lock(mm, pmd, addr, &ptl); | |
463 | break; | |
464 | } | |
465 | unlock_page(page); | |
466 | put_page(page); | |
467 | pte = pte_offset_map_lock(mm, pmd, addr, &ptl); | |
468 | pte--; | |
469 | addr -= PAGE_SIZE; | |
470 | continue; | |
471 | } | |
472 | ||
12e967fd MH |
473 | /* Do not interfere with other mappings of this page */ |
474 | if (page_mapcount(page) != 1) | |
475 | continue; | |
476 | ||
9c276cc6 MK |
477 | VM_BUG_ON_PAGE(PageTransCompound(page), page); |
478 | ||
479 | if (pte_young(ptent)) { | |
480 | ptent = ptep_get_and_clear_full(mm, addr, pte, | |
481 | tlb->fullmm); | |
482 | ptent = pte_mkold(ptent); | |
483 | set_pte_at(mm, addr, pte, ptent); | |
484 | tlb_remove_tlb_entry(tlb, pte, addr); | |
485 | } | |
486 | ||
487 | /* | |
488 | * We are deactivating a page for accelerating reclaiming. | |
489 | * VM couldn't reclaim the page unless we clear PG_young. | |
490 | * As a side effect, it makes confuse idle-page tracking | |
491 | * because they will miss recent referenced history. | |
492 | */ | |
d616d512 | 493 | ClearPageReferenced(page); |
9c276cc6 | 494 | test_and_clear_page_young(page); |
d616d512 | 495 | if (pageout) { |
82072962 | 496 | if (!isolate_lru_page(page)) { |
497 | if (PageUnevictable(page)) | |
498 | putback_lru_page(page); | |
499 | else | |
500 | list_add(&page->lru, &page_list); | |
501 | } | |
d616d512 MK |
502 | } else |
503 | deactivate_page(page); | |
9c276cc6 MK |
504 | } |
505 | ||
506 | arch_leave_lazy_mmu_mode(); | |
507 | pte_unmap_unlock(orig_pte, ptl); | |
d616d512 MK |
508 | if (pageout) |
509 | reclaim_pages(&page_list); | |
9c276cc6 MK |
510 | cond_resched(); |
511 | ||
512 | return 0; | |
513 | } | |
514 | ||
515 | static const struct mm_walk_ops cold_walk_ops = { | |
d616d512 | 516 | .pmd_entry = madvise_cold_or_pageout_pte_range, |
9c276cc6 MK |
517 | }; |
518 | ||
519 | static void madvise_cold_page_range(struct mmu_gather *tlb, | |
520 | struct vm_area_struct *vma, | |
521 | unsigned long addr, unsigned long end) | |
522 | { | |
d616d512 MK |
523 | struct madvise_walk_private walk_private = { |
524 | .pageout = false, | |
525 | .tlb = tlb, | |
526 | }; | |
527 | ||
9c276cc6 | 528 | tlb_start_vma(tlb, vma); |
d616d512 | 529 | walk_page_range(vma->vm_mm, addr, end, &cold_walk_ops, &walk_private); |
9c276cc6 MK |
530 | tlb_end_vma(tlb, vma); |
531 | } | |
532 | ||
533 | static long madvise_cold(struct vm_area_struct *vma, | |
534 | struct vm_area_struct **prev, | |
535 | unsigned long start_addr, unsigned long end_addr) | |
536 | { | |
537 | struct mm_struct *mm = vma->vm_mm; | |
538 | struct mmu_gather tlb; | |
539 | ||
540 | *prev = vma; | |
541 | if (!can_madv_lru_vma(vma)) | |
542 | return -EINVAL; | |
543 | ||
544 | lru_add_drain(); | |
a72afd87 | 545 | tlb_gather_mmu(&tlb, mm); |
9c276cc6 | 546 | madvise_cold_page_range(&tlb, vma, start_addr, end_addr); |
ae8eba8b | 547 | tlb_finish_mmu(&tlb); |
9c276cc6 MK |
548 | |
549 | return 0; | |
550 | } | |
551 | ||
1a4e58cc MK |
552 | static void madvise_pageout_page_range(struct mmu_gather *tlb, |
553 | struct vm_area_struct *vma, | |
554 | unsigned long addr, unsigned long end) | |
555 | { | |
d616d512 MK |
556 | struct madvise_walk_private walk_private = { |
557 | .pageout = true, | |
558 | .tlb = tlb, | |
559 | }; | |
560 | ||
1a4e58cc | 561 | tlb_start_vma(tlb, vma); |
d616d512 | 562 | walk_page_range(vma->vm_mm, addr, end, &cold_walk_ops, &walk_private); |
1a4e58cc MK |
563 | tlb_end_vma(tlb, vma); |
564 | } | |
565 | ||
566 | static inline bool can_do_pageout(struct vm_area_struct *vma) | |
567 | { | |
568 | if (vma_is_anonymous(vma)) | |
569 | return true; | |
570 | if (!vma->vm_file) | |
571 | return false; | |
572 | /* | |
573 | * paging out pagecache only for non-anonymous mappings that correspond | |
574 | * to the files the calling process could (if tried) open for writing; | |
575 | * otherwise we'd be including shared non-exclusive mappings, which | |
576 | * opens a side channel. | |
577 | */ | |
21cb47be CB |
578 | return inode_owner_or_capable(&init_user_ns, |
579 | file_inode(vma->vm_file)) || | |
02f92b38 | 580 | file_permission(vma->vm_file, MAY_WRITE) == 0; |
1a4e58cc MK |
581 | } |
582 | ||
583 | static long madvise_pageout(struct vm_area_struct *vma, | |
584 | struct vm_area_struct **prev, | |
585 | unsigned long start_addr, unsigned long end_addr) | |
586 | { | |
587 | struct mm_struct *mm = vma->vm_mm; | |
588 | struct mmu_gather tlb; | |
589 | ||
590 | *prev = vma; | |
591 | if (!can_madv_lru_vma(vma)) | |
592 | return -EINVAL; | |
593 | ||
594 | if (!can_do_pageout(vma)) | |
595 | return 0; | |
596 | ||
597 | lru_add_drain(); | |
a72afd87 | 598 | tlb_gather_mmu(&tlb, mm); |
1a4e58cc | 599 | madvise_pageout_page_range(&tlb, vma, start_addr, end_addr); |
ae8eba8b | 600 | tlb_finish_mmu(&tlb); |
1a4e58cc MK |
601 | |
602 | return 0; | |
603 | } | |
604 | ||
854e9ed0 MK |
605 | static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr, |
606 | unsigned long end, struct mm_walk *walk) | |
607 | ||
608 | { | |
609 | struct mmu_gather *tlb = walk->private; | |
610 | struct mm_struct *mm = tlb->mm; | |
611 | struct vm_area_struct *vma = walk->vma; | |
612 | spinlock_t *ptl; | |
613 | pte_t *orig_pte, *pte, ptent; | |
614 | struct page *page; | |
64b42bc1 | 615 | int nr_swap = 0; |
b8d3c4c3 MK |
616 | unsigned long next; |
617 | ||
618 | next = pmd_addr_end(addr, end); | |
619 | if (pmd_trans_huge(*pmd)) | |
620 | if (madvise_free_huge_pmd(tlb, vma, pmd, addr, next)) | |
621 | goto next; | |
854e9ed0 | 622 | |
854e9ed0 MK |
623 | if (pmd_trans_unstable(pmd)) |
624 | return 0; | |
625 | ||
ed6a7935 | 626 | tlb_change_page_size(tlb, PAGE_SIZE); |
854e9ed0 | 627 | orig_pte = pte = pte_offset_map_lock(mm, pmd, addr, &ptl); |
3ea27719 | 628 | flush_tlb_batched_pending(mm); |
854e9ed0 MK |
629 | arch_enter_lazy_mmu_mode(); |
630 | for (; addr != end; pte++, addr += PAGE_SIZE) { | |
631 | ptent = *pte; | |
632 | ||
64b42bc1 | 633 | if (pte_none(ptent)) |
854e9ed0 | 634 | continue; |
64b42bc1 MK |
635 | /* |
636 | * If the pte has swp_entry, just clear page table to | |
637 | * prevent swap-in which is more expensive rather than | |
638 | * (page allocation + zeroing). | |
639 | */ | |
640 | if (!pte_present(ptent)) { | |
641 | swp_entry_t entry; | |
642 | ||
643 | entry = pte_to_swp_entry(ptent); | |
644 | if (non_swap_entry(entry)) | |
645 | continue; | |
646 | nr_swap--; | |
647 | free_swap_and_cache(entry); | |
648 | pte_clear_not_present_full(mm, addr, pte, tlb->fullmm); | |
649 | continue; | |
650 | } | |
854e9ed0 | 651 | |
25b2995a | 652 | page = vm_normal_page(vma, addr, ptent); |
854e9ed0 MK |
653 | if (!page) |
654 | continue; | |
655 | ||
656 | /* | |
657 | * If pmd isn't transhuge but the page is THP and | |
658 | * is owned by only this process, split it and | |
659 | * deactivate all pages. | |
660 | */ | |
661 | if (PageTransCompound(page)) { | |
662 | if (page_mapcount(page) != 1) | |
663 | goto out; | |
664 | get_page(page); | |
665 | if (!trylock_page(page)) { | |
666 | put_page(page); | |
667 | goto out; | |
668 | } | |
669 | pte_unmap_unlock(orig_pte, ptl); | |
670 | if (split_huge_page(page)) { | |
671 | unlock_page(page); | |
672 | put_page(page); | |
673 | pte_offset_map_lock(mm, pmd, addr, &ptl); | |
674 | goto out; | |
675 | } | |
854e9ed0 | 676 | unlock_page(page); |
263630e8 | 677 | put_page(page); |
854e9ed0 MK |
678 | pte = pte_offset_map_lock(mm, pmd, addr, &ptl); |
679 | pte--; | |
680 | addr -= PAGE_SIZE; | |
681 | continue; | |
682 | } | |
683 | ||
684 | VM_BUG_ON_PAGE(PageTransCompound(page), page); | |
685 | ||
686 | if (PageSwapCache(page) || PageDirty(page)) { | |
687 | if (!trylock_page(page)) | |
688 | continue; | |
689 | /* | |
690 | * If page is shared with others, we couldn't clear | |
691 | * PG_dirty of the page. | |
692 | */ | |
693 | if (page_mapcount(page) != 1) { | |
694 | unlock_page(page); | |
695 | continue; | |
696 | } | |
697 | ||
698 | if (PageSwapCache(page) && !try_to_free_swap(page)) { | |
699 | unlock_page(page); | |
700 | continue; | |
701 | } | |
702 | ||
703 | ClearPageDirty(page); | |
704 | unlock_page(page); | |
705 | } | |
706 | ||
707 | if (pte_young(ptent) || pte_dirty(ptent)) { | |
708 | /* | |
709 | * Some of architecture(ex, PPC) don't update TLB | |
710 | * with set_pte_at and tlb_remove_tlb_entry so for | |
711 | * the portability, remap the pte with old|clean | |
712 | * after pte clearing. | |
713 | */ | |
714 | ptent = ptep_get_and_clear_full(mm, addr, pte, | |
715 | tlb->fullmm); | |
716 | ||
717 | ptent = pte_mkold(ptent); | |
718 | ptent = pte_mkclean(ptent); | |
719 | set_pte_at(mm, addr, pte, ptent); | |
720 | tlb_remove_tlb_entry(tlb, pte, addr); | |
721 | } | |
802a3a92 | 722 | mark_page_lazyfree(page); |
854e9ed0 MK |
723 | } |
724 | out: | |
64b42bc1 MK |
725 | if (nr_swap) { |
726 | if (current->mm == mm) | |
727 | sync_mm_rss(mm); | |
728 | ||
729 | add_mm_counter(mm, MM_SWAPENTS, nr_swap); | |
730 | } | |
854e9ed0 MK |
731 | arch_leave_lazy_mmu_mode(); |
732 | pte_unmap_unlock(orig_pte, ptl); | |
733 | cond_resched(); | |
b8d3c4c3 | 734 | next: |
854e9ed0 MK |
735 | return 0; |
736 | } | |
737 | ||
7b86ac33 CH |
738 | static const struct mm_walk_ops madvise_free_walk_ops = { |
739 | .pmd_entry = madvise_free_pte_range, | |
740 | }; | |
854e9ed0 MK |
741 | |
742 | static int madvise_free_single_vma(struct vm_area_struct *vma, | |
743 | unsigned long start_addr, unsigned long end_addr) | |
744 | { | |
854e9ed0 | 745 | struct mm_struct *mm = vma->vm_mm; |
ac46d4f3 | 746 | struct mmu_notifier_range range; |
854e9ed0 MK |
747 | struct mmu_gather tlb; |
748 | ||
854e9ed0 MK |
749 | /* MADV_FREE works for only anon vma at the moment */ |
750 | if (!vma_is_anonymous(vma)) | |
751 | return -EINVAL; | |
752 | ||
ac46d4f3 JG |
753 | range.start = max(vma->vm_start, start_addr); |
754 | if (range.start >= vma->vm_end) | |
854e9ed0 | 755 | return -EINVAL; |
ac46d4f3 JG |
756 | range.end = min(vma->vm_end, end_addr); |
757 | if (range.end <= vma->vm_start) | |
854e9ed0 | 758 | return -EINVAL; |
7269f999 | 759 | mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, |
6f4f13e8 | 760 | range.start, range.end); |
854e9ed0 MK |
761 | |
762 | lru_add_drain(); | |
a72afd87 | 763 | tlb_gather_mmu(&tlb, mm); |
854e9ed0 MK |
764 | update_hiwater_rss(mm); |
765 | ||
ac46d4f3 | 766 | mmu_notifier_invalidate_range_start(&range); |
7b86ac33 CH |
767 | tlb_start_vma(&tlb, vma); |
768 | walk_page_range(vma->vm_mm, range.start, range.end, | |
769 | &madvise_free_walk_ops, &tlb); | |
770 | tlb_end_vma(&tlb, vma); | |
ac46d4f3 | 771 | mmu_notifier_invalidate_range_end(&range); |
ae8eba8b | 772 | tlb_finish_mmu(&tlb); |
854e9ed0 MK |
773 | |
774 | return 0; | |
775 | } | |
776 | ||
1da177e4 LT |
777 | /* |
778 | * Application no longer needs these pages. If the pages are dirty, | |
779 | * it's OK to just throw them away. The app will be more careful about | |
780 | * data it wants to keep. Be sure to free swap resources too. The | |
7e6cbea3 | 781 | * zap_page_range call sets things up for shrink_active_list to actually free |
1da177e4 LT |
782 | * these pages later if no one else has touched them in the meantime, |
783 | * although we could add these pages to a global reuse list for | |
7e6cbea3 | 784 | * shrink_active_list to pick up before reclaiming other pages. |
1da177e4 LT |
785 | * |
786 | * NB: This interface discards data rather than pushes it out to swap, | |
787 | * as some implementations do. This has performance implications for | |
788 | * applications like large transactional databases which want to discard | |
789 | * pages in anonymous maps after committing to backing store the data | |
790 | * that was kept in them. There is no reason to write this data out to | |
791 | * the swap area if the application is discarding it. | |
792 | * | |
793 | * An interface that causes the system to free clean pages and flush | |
794 | * dirty pages is already available as msync(MS_INVALIDATE). | |
795 | */ | |
230ca982 MR |
796 | static long madvise_dontneed_single_vma(struct vm_area_struct *vma, |
797 | unsigned long start, unsigned long end) | |
798 | { | |
799 | zap_page_range(vma, start, end - start); | |
800 | return 0; | |
801 | } | |
802 | ||
803 | static long madvise_dontneed_free(struct vm_area_struct *vma, | |
804 | struct vm_area_struct **prev, | |
805 | unsigned long start, unsigned long end, | |
806 | int behavior) | |
1da177e4 | 807 | { |
0726b01e MK |
808 | struct mm_struct *mm = vma->vm_mm; |
809 | ||
05b74384 | 810 | *prev = vma; |
9c276cc6 | 811 | if (!can_madv_lru_vma(vma)) |
1da177e4 LT |
812 | return -EINVAL; |
813 | ||
70ccb92f | 814 | if (!userfaultfd_remove(vma, start, end)) { |
c1e8d7c6 | 815 | *prev = NULL; /* mmap_lock has been dropped, prev is stale */ |
70ccb92f | 816 | |
0726b01e MK |
817 | mmap_read_lock(mm); |
818 | vma = find_vma(mm, start); | |
70ccb92f AA |
819 | if (!vma) |
820 | return -ENOMEM; | |
821 | if (start < vma->vm_start) { | |
822 | /* | |
823 | * This "vma" under revalidation is the one | |
824 | * with the lowest vma->vm_start where start | |
825 | * is also < vma->vm_end. If start < | |
826 | * vma->vm_start it means an hole materialized | |
827 | * in the user address space within the | |
230ca982 MR |
828 | * virtual range passed to MADV_DONTNEED |
829 | * or MADV_FREE. | |
70ccb92f AA |
830 | */ |
831 | return -ENOMEM; | |
832 | } | |
9c276cc6 | 833 | if (!can_madv_lru_vma(vma)) |
70ccb92f AA |
834 | return -EINVAL; |
835 | if (end > vma->vm_end) { | |
836 | /* | |
837 | * Don't fail if end > vma->vm_end. If the old | |
f0953a1b | 838 | * vma was split while the mmap_lock was |
70ccb92f | 839 | * released the effect of the concurrent |
230ca982 | 840 | * operation may not cause madvise() to |
70ccb92f AA |
841 | * have an undefined result. There may be an |
842 | * adjacent next vma that we'll walk | |
843 | * next. userfaultfd_remove() will generate an | |
844 | * UFFD_EVENT_REMOVE repetition on the | |
845 | * end-vma->vm_end range, but the manager can | |
846 | * handle a repetition fine. | |
847 | */ | |
848 | end = vma->vm_end; | |
849 | } | |
850 | VM_WARN_ON(start >= end); | |
851 | } | |
230ca982 MR |
852 | |
853 | if (behavior == MADV_DONTNEED) | |
854 | return madvise_dontneed_single_vma(vma, start, end); | |
855 | else if (behavior == MADV_FREE) | |
856 | return madvise_free_single_vma(vma, start, end); | |
857 | else | |
858 | return -EINVAL; | |
1da177e4 LT |
859 | } |
860 | ||
4ca9b385 DH |
861 | static long madvise_populate(struct vm_area_struct *vma, |
862 | struct vm_area_struct **prev, | |
863 | unsigned long start, unsigned long end, | |
864 | int behavior) | |
865 | { | |
866 | const bool write = behavior == MADV_POPULATE_WRITE; | |
867 | struct mm_struct *mm = vma->vm_mm; | |
868 | unsigned long tmp_end; | |
869 | int locked = 1; | |
870 | long pages; | |
871 | ||
872 | *prev = vma; | |
873 | ||
874 | while (start < end) { | |
875 | /* | |
876 | * We might have temporarily dropped the lock. For example, | |
877 | * our VMA might have been split. | |
878 | */ | |
879 | if (!vma || start >= vma->vm_end) { | |
880 | vma = find_vma(mm, start); | |
881 | if (!vma || start < vma->vm_start) | |
882 | return -ENOMEM; | |
883 | } | |
884 | ||
885 | tmp_end = min_t(unsigned long, end, vma->vm_end); | |
886 | /* Populate (prefault) page tables readable/writable. */ | |
887 | pages = faultin_vma_page_range(vma, start, tmp_end, write, | |
888 | &locked); | |
889 | if (!locked) { | |
890 | mmap_read_lock(mm); | |
891 | locked = 1; | |
892 | *prev = NULL; | |
893 | vma = NULL; | |
894 | } | |
895 | if (pages < 0) { | |
896 | switch (pages) { | |
897 | case -EINTR: | |
898 | return -EINTR; | |
eb2faa51 | 899 | case -EINVAL: /* Incompatible mappings / permissions. */ |
4ca9b385 DH |
900 | return -EINVAL; |
901 | case -EHWPOISON: | |
902 | return -EHWPOISON; | |
eb2faa51 DH |
903 | case -EFAULT: /* VM_FAULT_SIGBUS or VM_FAULT_SIGSEGV */ |
904 | return -EFAULT; | |
4ca9b385 DH |
905 | default: |
906 | pr_warn_once("%s: unhandled return value: %ld\n", | |
907 | __func__, pages); | |
908 | fallthrough; | |
909 | case -ENOMEM: | |
910 | return -ENOMEM; | |
911 | } | |
912 | } | |
913 | start += pages * PAGE_SIZE; | |
914 | } | |
915 | return 0; | |
916 | } | |
917 | ||
f6b3ec23 BP |
918 | /* |
919 | * Application wants to free up the pages and associated backing store. | |
920 | * This is effectively punching a hole into the middle of a file. | |
f6b3ec23 BP |
921 | */ |
922 | static long madvise_remove(struct vm_area_struct *vma, | |
00e9fa2d | 923 | struct vm_area_struct **prev, |
f6b3ec23 BP |
924 | unsigned long start, unsigned long end) |
925 | { | |
3f31d075 | 926 | loff_t offset; |
90ed52eb | 927 | int error; |
9ab4233d | 928 | struct file *f; |
0726b01e | 929 | struct mm_struct *mm = vma->vm_mm; |
f6b3ec23 | 930 | |
c1e8d7c6 | 931 | *prev = NULL; /* tell sys_madvise we drop mmap_lock */ |
00e9fa2d | 932 | |
72079ba0 | 933 | if (vma->vm_flags & VM_LOCKED) |
f6b3ec23 BP |
934 | return -EINVAL; |
935 | ||
9ab4233d AL |
936 | f = vma->vm_file; |
937 | ||
938 | if (!f || !f->f_mapping || !f->f_mapping->host) { | |
f6b3ec23 BP |
939 | return -EINVAL; |
940 | } | |
941 | ||
69cf0fac HD |
942 | if ((vma->vm_flags & (VM_SHARED|VM_WRITE)) != (VM_SHARED|VM_WRITE)) |
943 | return -EACCES; | |
944 | ||
f6b3ec23 BP |
945 | offset = (loff_t)(start - vma->vm_start) |
946 | + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); | |
90ed52eb | 947 | |
9ab4233d | 948 | /* |
9608703e | 949 | * Filesystem's fallocate may need to take i_rwsem. We need to |
9ab4233d AL |
950 | * explicitly grab a reference because the vma (and hence the |
951 | * vma's reference to the file) can go away as soon as we drop | |
c1e8d7c6 | 952 | * mmap_lock. |
9ab4233d AL |
953 | */ |
954 | get_file(f); | |
70ccb92f | 955 | if (userfaultfd_remove(vma, start, end)) { |
c1e8d7c6 | 956 | /* mmap_lock was not released by userfaultfd_remove() */ |
0726b01e | 957 | mmap_read_unlock(mm); |
70ccb92f | 958 | } |
72c72bdf | 959 | error = vfs_fallocate(f, |
3f31d075 HD |
960 | FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, |
961 | offset, end - start); | |
9ab4233d | 962 | fput(f); |
0726b01e | 963 | mmap_read_lock(mm); |
90ed52eb | 964 | return error; |
f6b3ec23 BP |
965 | } |
966 | ||
ac1e9acc CC |
967 | /* |
968 | * Apply an madvise behavior to a region of a vma. madvise_update_vma | |
969 | * will handle splitting a vm area into separate areas, each area with its own | |
970 | * behavior. | |
971 | */ | |
972 | static int madvise_vma_behavior(struct vm_area_struct *vma, | |
973 | struct vm_area_struct **prev, | |
974 | unsigned long start, unsigned long end, | |
975 | unsigned long behavior) | |
976 | { | |
977 | int error; | |
978 | unsigned long new_flags = vma->vm_flags; | |
979 | ||
980 | switch (behavior) { | |
981 | case MADV_REMOVE: | |
982 | return madvise_remove(vma, prev, start, end); | |
983 | case MADV_WILLNEED: | |
984 | return madvise_willneed(vma, prev, start, end); | |
985 | case MADV_COLD: | |
986 | return madvise_cold(vma, prev, start, end); | |
987 | case MADV_PAGEOUT: | |
988 | return madvise_pageout(vma, prev, start, end); | |
989 | case MADV_FREE: | |
990 | case MADV_DONTNEED: | |
991 | return madvise_dontneed_free(vma, prev, start, end, behavior); | |
992 | case MADV_POPULATE_READ: | |
993 | case MADV_POPULATE_WRITE: | |
994 | return madvise_populate(vma, prev, start, end, behavior); | |
995 | case MADV_NORMAL: | |
996 | new_flags = new_flags & ~VM_RAND_READ & ~VM_SEQ_READ; | |
997 | break; | |
998 | case MADV_SEQUENTIAL: | |
999 | new_flags = (new_flags & ~VM_RAND_READ) | VM_SEQ_READ; | |
1000 | break; | |
1001 | case MADV_RANDOM: | |
1002 | new_flags = (new_flags & ~VM_SEQ_READ) | VM_RAND_READ; | |
1003 | break; | |
1004 | case MADV_DONTFORK: | |
1005 | new_flags |= VM_DONTCOPY; | |
1006 | break; | |
1007 | case MADV_DOFORK: | |
1008 | if (vma->vm_flags & VM_IO) | |
1009 | return -EINVAL; | |
1010 | new_flags &= ~VM_DONTCOPY; | |
1011 | break; | |
1012 | case MADV_WIPEONFORK: | |
1013 | /* MADV_WIPEONFORK is only supported on anonymous memory. */ | |
1014 | if (vma->vm_file || vma->vm_flags & VM_SHARED) | |
1015 | return -EINVAL; | |
1016 | new_flags |= VM_WIPEONFORK; | |
1017 | break; | |
1018 | case MADV_KEEPONFORK: | |
1019 | new_flags &= ~VM_WIPEONFORK; | |
1020 | break; | |
1021 | case MADV_DONTDUMP: | |
1022 | new_flags |= VM_DONTDUMP; | |
1023 | break; | |
1024 | case MADV_DODUMP: | |
1025 | if (!is_vm_hugetlb_page(vma) && new_flags & VM_SPECIAL) | |
1026 | return -EINVAL; | |
1027 | new_flags &= ~VM_DONTDUMP; | |
1028 | break; | |
1029 | case MADV_MERGEABLE: | |
1030 | case MADV_UNMERGEABLE: | |
1031 | error = ksm_madvise(vma, start, end, behavior, &new_flags); | |
1032 | if (error) | |
1033 | goto out; | |
1034 | break; | |
1035 | case MADV_HUGEPAGE: | |
1036 | case MADV_NOHUGEPAGE: | |
1037 | error = hugepage_madvise(vma, &new_flags, behavior); | |
1038 | if (error) | |
1039 | goto out; | |
1040 | break; | |
1041 | } | |
1042 | ||
9a10064f CC |
1043 | error = madvise_update_vma(vma, prev, start, end, new_flags, |
1044 | vma_anon_name(vma)); | |
ac1e9acc CC |
1045 | |
1046 | out: | |
1047 | /* | |
1048 | * madvise() returns EAGAIN if kernel resources, such as | |
1049 | * slab, are temporarily unavailable. | |
1050 | */ | |
1051 | if (error == -ENOMEM) | |
1052 | error = -EAGAIN; | |
1053 | return error; | |
1054 | } | |
1055 | ||
9893e49d AK |
1056 | #ifdef CONFIG_MEMORY_FAILURE |
1057 | /* | |
1058 | * Error injection support for memory error handling. | |
1059 | */ | |
97167a76 AK |
1060 | static int madvise_inject_error(int behavior, |
1061 | unsigned long start, unsigned long end) | |
9893e49d | 1062 | { |
d3cd257c | 1063 | unsigned long size; |
97167a76 | 1064 | |
9893e49d AK |
1065 | if (!capable(CAP_SYS_ADMIN)) |
1066 | return -EPERM; | |
97167a76 | 1067 | |
19bfbe22 | 1068 | |
d3cd257c | 1069 | for (; start < end; start += size) { |
23e7b5c2 | 1070 | unsigned long pfn; |
dc7560b4 | 1071 | struct page *page; |
325c4ef5 AM |
1072 | int ret; |
1073 | ||
97167a76 | 1074 | ret = get_user_pages_fast(start, 1, 0, &page); |
9893e49d AK |
1075 | if (ret != 1) |
1076 | return ret; | |
23e7b5c2 | 1077 | pfn = page_to_pfn(page); |
325c4ef5 | 1078 | |
19bfbe22 AM |
1079 | /* |
1080 | * When soft offlining hugepages, after migrating the page | |
1081 | * we dissolve it, therefore in the second loop "page" will | |
d3cd257c | 1082 | * no longer be a compound page. |
19bfbe22 | 1083 | */ |
d3cd257c | 1084 | size = page_size(compound_head(page)); |
19bfbe22 | 1085 | |
97167a76 AK |
1086 | if (behavior == MADV_SOFT_OFFLINE) { |
1087 | pr_info("Soft offlining pfn %#lx at process virtual address %#lx\n", | |
dc7560b4 | 1088 | pfn, start); |
feec24a6 | 1089 | ret = soft_offline_page(pfn, MF_COUNT_INCREASED); |
dc7560b4 OS |
1090 | } else { |
1091 | pr_info("Injecting memory failure for pfn %#lx at process virtual address %#lx\n", | |
1092 | pfn, start); | |
1e8aaedb | 1093 | ret = memory_failure(pfn, MF_COUNT_INCREASED); |
afcf938e | 1094 | } |
23e7b5c2 | 1095 | |
23a003bf NH |
1096 | if (ret) |
1097 | return ret; | |
9893e49d | 1098 | } |
c461ad6a | 1099 | |
325c4ef5 | 1100 | return 0; |
9893e49d AK |
1101 | } |
1102 | #endif | |
1103 | ||
1ecef9ed | 1104 | static bool |
75927af8 NP |
1105 | madvise_behavior_valid(int behavior) |
1106 | { | |
1107 | switch (behavior) { | |
1108 | case MADV_DOFORK: | |
1109 | case MADV_DONTFORK: | |
1110 | case MADV_NORMAL: | |
1111 | case MADV_SEQUENTIAL: | |
1112 | case MADV_RANDOM: | |
1113 | case MADV_REMOVE: | |
1114 | case MADV_WILLNEED: | |
1115 | case MADV_DONTNEED: | |
854e9ed0 | 1116 | case MADV_FREE: |
9c276cc6 | 1117 | case MADV_COLD: |
1a4e58cc | 1118 | case MADV_PAGEOUT: |
4ca9b385 DH |
1119 | case MADV_POPULATE_READ: |
1120 | case MADV_POPULATE_WRITE: | |
f8af4da3 HD |
1121 | #ifdef CONFIG_KSM |
1122 | case MADV_MERGEABLE: | |
1123 | case MADV_UNMERGEABLE: | |
0af4e98b AA |
1124 | #endif |
1125 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE | |
1126 | case MADV_HUGEPAGE: | |
a664b2d8 | 1127 | case MADV_NOHUGEPAGE: |
f8af4da3 | 1128 | #endif |
accb61fe JB |
1129 | case MADV_DONTDUMP: |
1130 | case MADV_DODUMP: | |
d2cd9ede RR |
1131 | case MADV_WIPEONFORK: |
1132 | case MADV_KEEPONFORK: | |
5e451be7 AK |
1133 | #ifdef CONFIG_MEMORY_FAILURE |
1134 | case MADV_SOFT_OFFLINE: | |
1135 | case MADV_HWPOISON: | |
1136 | #endif | |
1ecef9ed | 1137 | return true; |
75927af8 NP |
1138 | |
1139 | default: | |
1ecef9ed | 1140 | return false; |
75927af8 NP |
1141 | } |
1142 | } | |
3866ea90 | 1143 | |
ecb8ac8b MK |
1144 | static bool |
1145 | process_madvise_behavior_valid(int behavior) | |
1146 | { | |
1147 | switch (behavior) { | |
1148 | case MADV_COLD: | |
1149 | case MADV_PAGEOUT: | |
d5fffc5a | 1150 | case MADV_WILLNEED: |
ecb8ac8b MK |
1151 | return true; |
1152 | default: | |
1153 | return false; | |
1154 | } | |
1155 | } | |
1156 | ||
ac1e9acc CC |
1157 | /* |
1158 | * Walk the vmas in range [start,end), and call the visit function on each one. | |
1159 | * The visit function will get start and end parameters that cover the overlap | |
1160 | * between the current vma and the original range. Any unmapped regions in the | |
1161 | * original range will result in this function returning -ENOMEM while still | |
1162 | * calling the visit function on all of the existing vmas in the range. | |
1163 | * Must be called with the mmap_lock held for reading or writing. | |
1164 | */ | |
1165 | static | |
1166 | int madvise_walk_vmas(struct mm_struct *mm, unsigned long start, | |
1167 | unsigned long end, unsigned long arg, | |
1168 | int (*visit)(struct vm_area_struct *vma, | |
1169 | struct vm_area_struct **prev, unsigned long start, | |
1170 | unsigned long end, unsigned long arg)) | |
1171 | { | |
1172 | struct vm_area_struct *vma; | |
1173 | struct vm_area_struct *prev; | |
1174 | unsigned long tmp; | |
1175 | int unmapped_error = 0; | |
1176 | ||
1177 | /* | |
1178 | * If the interval [start,end) covers some unmapped address | |
1179 | * ranges, just ignore them, but return -ENOMEM at the end. | |
1180 | * - different from the way of handling in mlock etc. | |
1181 | */ | |
1182 | vma = find_vma_prev(mm, start, &prev); | |
1183 | if (vma && start > vma->vm_start) | |
1184 | prev = vma; | |
1185 | ||
1186 | for (;;) { | |
1187 | int error; | |
1188 | ||
1189 | /* Still start < end. */ | |
1190 | if (!vma) | |
1191 | return -ENOMEM; | |
1192 | ||
1193 | /* Here start < (end|vma->vm_end). */ | |
1194 | if (start < vma->vm_start) { | |
1195 | unmapped_error = -ENOMEM; | |
1196 | start = vma->vm_start; | |
1197 | if (start >= end) | |
1198 | break; | |
1199 | } | |
1200 | ||
1201 | /* Here vma->vm_start <= start < (end|vma->vm_end) */ | |
1202 | tmp = vma->vm_end; | |
1203 | if (end < tmp) | |
1204 | tmp = end; | |
1205 | ||
1206 | /* Here vma->vm_start <= start < tmp <= (end|vma->vm_end). */ | |
1207 | error = visit(vma, &prev, start, tmp, arg); | |
1208 | if (error) | |
1209 | return error; | |
1210 | start = tmp; | |
1211 | if (prev && start < prev->vm_end) | |
1212 | start = prev->vm_end; | |
1213 | if (start >= end) | |
1214 | break; | |
1215 | if (prev) | |
1216 | vma = prev->vm_next; | |
1217 | else /* madvise_remove dropped mmap_lock */ | |
1218 | vma = find_vma(mm, start); | |
1219 | } | |
1220 | ||
1221 | return unmapped_error; | |
1222 | } | |
1223 | ||
9a10064f CC |
1224 | #ifdef CONFIG_ANON_VMA_NAME |
1225 | static int madvise_vma_anon_name(struct vm_area_struct *vma, | |
1226 | struct vm_area_struct **prev, | |
1227 | unsigned long start, unsigned long end, | |
1228 | unsigned long name) | |
1229 | { | |
1230 | int error; | |
1231 | ||
1232 | /* Only anonymous mappings can be named */ | |
1233 | if (vma->vm_file) | |
1234 | return -EBADF; | |
1235 | ||
1236 | error = madvise_update_vma(vma, prev, start, end, vma->vm_flags, | |
1237 | (const char *)name); | |
1238 | ||
1239 | /* | |
1240 | * madvise() returns EAGAIN if kernel resources, such as | |
1241 | * slab, are temporarily unavailable. | |
1242 | */ | |
1243 | if (error == -ENOMEM) | |
1244 | error = -EAGAIN; | |
1245 | return error; | |
1246 | } | |
1247 | ||
1248 | int madvise_set_anon_name(struct mm_struct *mm, unsigned long start, | |
1249 | unsigned long len_in, const char *name) | |
1250 | { | |
1251 | unsigned long end; | |
1252 | unsigned long len; | |
1253 | ||
1254 | if (start & ~PAGE_MASK) | |
1255 | return -EINVAL; | |
1256 | len = (len_in + ~PAGE_MASK) & PAGE_MASK; | |
1257 | ||
1258 | /* Check to see whether len was rounded up from small -ve to zero */ | |
1259 | if (len_in && !len) | |
1260 | return -EINVAL; | |
1261 | ||
1262 | end = start + len; | |
1263 | if (end < start) | |
1264 | return -EINVAL; | |
1265 | ||
1266 | if (end == start) | |
1267 | return 0; | |
1268 | ||
1269 | return madvise_walk_vmas(mm, start, end, (unsigned long)name, | |
1270 | madvise_vma_anon_name); | |
1271 | } | |
1272 | #endif /* CONFIG_ANON_VMA_NAME */ | |
1da177e4 LT |
1273 | /* |
1274 | * The madvise(2) system call. | |
1275 | * | |
1276 | * Applications can use madvise() to advise the kernel how it should | |
1277 | * handle paging I/O in this VM area. The idea is to help the kernel | |
1278 | * use appropriate read-ahead and caching techniques. The information | |
1279 | * provided is advisory only, and can be safely disregarded by the | |
1280 | * kernel without affecting the correct operation of the application. | |
1281 | * | |
1282 | * behavior values: | |
1283 | * MADV_NORMAL - the default behavior is to read clusters. This | |
1284 | * results in some read-ahead and read-behind. | |
1285 | * MADV_RANDOM - the system should read the minimum amount of data | |
1286 | * on any access, since it is unlikely that the appli- | |
1287 | * cation will need more than what it asks for. | |
1288 | * MADV_SEQUENTIAL - pages in the given range will probably be accessed | |
1289 | * once, so they can be aggressively read ahead, and | |
1290 | * can be freed soon after they are accessed. | |
1291 | * MADV_WILLNEED - the application is notifying the system to read | |
1292 | * some pages ahead. | |
1293 | * MADV_DONTNEED - the application is finished with the given range, | |
1294 | * so the kernel can free resources associated with it. | |
d7206a70 NH |
1295 | * MADV_FREE - the application marks pages in the given range as lazy free, |
1296 | * where actual purges are postponed until memory pressure happens. | |
f6b3ec23 BP |
1297 | * MADV_REMOVE - the application wants to free up the given range of |
1298 | * pages and associated backing store. | |
3866ea90 HD |
1299 | * MADV_DONTFORK - omit this area from child's address space when forking: |
1300 | * typically, to avoid COWing pages pinned by get_user_pages(). | |
1301 | * MADV_DOFORK - cancel MADV_DONTFORK: no longer omit this area when forking. | |
c02c3009 YS |
1302 | * MADV_WIPEONFORK - present the child process with zero-filled memory in this |
1303 | * range after a fork. | |
1304 | * MADV_KEEPONFORK - undo the effect of MADV_WIPEONFORK | |
d7206a70 NH |
1305 | * MADV_HWPOISON - trigger memory error handler as if the given memory range |
1306 | * were corrupted by unrecoverable hardware memory failure. | |
1307 | * MADV_SOFT_OFFLINE - try to soft-offline the given range of memory. | |
f8af4da3 HD |
1308 | * MADV_MERGEABLE - the application recommends that KSM try to merge pages in |
1309 | * this area with pages of identical content from other such areas. | |
1310 | * MADV_UNMERGEABLE- cancel MADV_MERGEABLE: no longer merge pages with others. | |
d7206a70 NH |
1311 | * MADV_HUGEPAGE - the application wants to back the given range by transparent |
1312 | * huge pages in the future. Existing pages might be coalesced and | |
1313 | * new pages might be allocated as THP. | |
1314 | * MADV_NOHUGEPAGE - mark the given range as not worth being backed by | |
1315 | * transparent huge pages so the existing pages will not be | |
1316 | * coalesced into THP and new pages will not be allocated as THP. | |
1317 | * MADV_DONTDUMP - the application wants to prevent pages in the given range | |
1318 | * from being included in its core dump. | |
1319 | * MADV_DODUMP - cancel MADV_DONTDUMP: no longer exclude from core dump. | |
ecb8ac8b MK |
1320 | * MADV_COLD - the application is not expected to use this memory soon, |
1321 | * deactivate pages in this range so that they can be reclaimed | |
f0953a1b | 1322 | * easily if memory pressure happens. |
ecb8ac8b MK |
1323 | * MADV_PAGEOUT - the application is not expected to use this memory soon, |
1324 | * page out the pages in this range immediately. | |
4ca9b385 DH |
1325 | * MADV_POPULATE_READ - populate (prefault) page tables readable by |
1326 | * triggering read faults if required | |
1327 | * MADV_POPULATE_WRITE - populate (prefault) page tables writable by | |
1328 | * triggering write faults if required | |
1da177e4 LT |
1329 | * |
1330 | * return values: | |
1331 | * zero - success | |
1332 | * -EINVAL - start + len < 0, start is not page-aligned, | |
1333 | * "behavior" is not a valid value, or application | |
c02c3009 YS |
1334 | * is attempting to release locked or shared pages, |
1335 | * or the specified address range includes file, Huge TLB, | |
1336 | * MAP_SHARED or VMPFNMAP range. | |
1da177e4 LT |
1337 | * -ENOMEM - addresses in the specified range are not currently |
1338 | * mapped, or are outside the AS of the process. | |
1339 | * -EIO - an I/O error occurred while paging in data. | |
1340 | * -EBADF - map exists, but area maps something that isn't a file. | |
1341 | * -EAGAIN - a kernel resource was temporarily unavailable. | |
1342 | */ | |
0726b01e | 1343 | int do_madvise(struct mm_struct *mm, unsigned long start, size_t len_in, int behavior) |
1da177e4 | 1344 | { |
ac1e9acc CC |
1345 | unsigned long end; |
1346 | int error; | |
f7977793 | 1347 | int write; |
1da177e4 | 1348 | size_t len; |
1998cc04 | 1349 | struct blk_plug plug; |
1da177e4 | 1350 | |
057d3389 AK |
1351 | start = untagged_addr(start); |
1352 | ||
75927af8 | 1353 | if (!madvise_behavior_valid(behavior)) |
ac1e9acc | 1354 | return -EINVAL; |
75927af8 | 1355 | |
df6c6500 | 1356 | if (!PAGE_ALIGNED(start)) |
ac1e9acc | 1357 | return -EINVAL; |
df6c6500 | 1358 | len = PAGE_ALIGN(len_in); |
1da177e4 LT |
1359 | |
1360 | /* Check to see whether len was rounded up from small -ve to zero */ | |
1361 | if (len_in && !len) | |
ac1e9acc | 1362 | return -EINVAL; |
1da177e4 LT |
1363 | |
1364 | end = start + len; | |
1365 | if (end < start) | |
ac1e9acc | 1366 | return -EINVAL; |
1da177e4 | 1367 | |
1da177e4 | 1368 | if (end == start) |
ac1e9acc | 1369 | return 0; |
84d96d89 | 1370 | |
5e451be7 AK |
1371 | #ifdef CONFIG_MEMORY_FAILURE |
1372 | if (behavior == MADV_HWPOISON || behavior == MADV_SOFT_OFFLINE) | |
1373 | return madvise_inject_error(behavior, start, start + len_in); | |
1374 | #endif | |
1375 | ||
84d96d89 | 1376 | write = madvise_need_mmap_write(behavior); |
dc0ef0df | 1377 | if (write) { |
0726b01e | 1378 | if (mmap_write_lock_killable(mm)) |
dc0ef0df MH |
1379 | return -EINTR; |
1380 | } else { | |
0726b01e | 1381 | mmap_read_lock(mm); |
dc0ef0df | 1382 | } |
1da177e4 | 1383 | |
1998cc04 | 1384 | blk_start_plug(&plug); |
ac1e9acc CC |
1385 | error = madvise_walk_vmas(mm, start, end, behavior, |
1386 | madvise_vma_behavior); | |
84d96d89 | 1387 | blk_finish_plug(&plug); |
f7977793 | 1388 | if (write) |
0726b01e | 1389 | mmap_write_unlock(mm); |
0a27a14a | 1390 | else |
0726b01e | 1391 | mmap_read_unlock(mm); |
0a27a14a | 1392 | |
1da177e4 LT |
1393 | return error; |
1394 | } | |
db08ca25 JA |
1395 | |
1396 | SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior) | |
1397 | { | |
0726b01e | 1398 | return do_madvise(current->mm, start, len_in, behavior); |
db08ca25 | 1399 | } |
ecb8ac8b MK |
1400 | |
1401 | SYSCALL_DEFINE5(process_madvise, int, pidfd, const struct iovec __user *, vec, | |
1402 | size_t, vlen, int, behavior, unsigned int, flags) | |
1403 | { | |
1404 | ssize_t ret; | |
1405 | struct iovec iovstack[UIO_FASTIOV], iovec; | |
1406 | struct iovec *iov = iovstack; | |
1407 | struct iov_iter iter; | |
ecb8ac8b MK |
1408 | struct task_struct *task; |
1409 | struct mm_struct *mm; | |
1410 | size_t total_len; | |
1411 | unsigned int f_flags; | |
1412 | ||
1413 | if (flags != 0) { | |
1414 | ret = -EINVAL; | |
1415 | goto out; | |
1416 | } | |
1417 | ||
1418 | ret = import_iovec(READ, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter); | |
1419 | if (ret < 0) | |
1420 | goto out; | |
1421 | ||
ee9955d6 CB |
1422 | task = pidfd_get_task(pidfd, &f_flags); |
1423 | if (IS_ERR(task)) { | |
1424 | ret = PTR_ERR(task); | |
ecb8ac8b MK |
1425 | goto free_iov; |
1426 | } | |
1427 | ||
a68a0262 | 1428 | if (!process_madvise_behavior_valid(behavior)) { |
ecb8ac8b MK |
1429 | ret = -EINVAL; |
1430 | goto release_task; | |
1431 | } | |
1432 | ||
96cfe2c0 SB |
1433 | /* Require PTRACE_MODE_READ to avoid leaking ASLR metadata. */ |
1434 | mm = mm_access(task, PTRACE_MODE_READ_FSCREDS); | |
ecb8ac8b MK |
1435 | if (IS_ERR_OR_NULL(mm)) { |
1436 | ret = IS_ERR(mm) ? PTR_ERR(mm) : -ESRCH; | |
1437 | goto release_task; | |
1438 | } | |
1439 | ||
96cfe2c0 SB |
1440 | /* |
1441 | * Require CAP_SYS_NICE for influencing process performance. Note that | |
1442 | * only non-destructive hints are currently supported. | |
1443 | */ | |
1444 | if (!capable(CAP_SYS_NICE)) { | |
1445 | ret = -EPERM; | |
1446 | goto release_mm; | |
1447 | } | |
1448 | ||
ecb8ac8b MK |
1449 | total_len = iov_iter_count(&iter); |
1450 | ||
1451 | while (iov_iter_count(&iter)) { | |
1452 | iovec = iov_iter_iovec(&iter); | |
1453 | ret = do_madvise(mm, (unsigned long)iovec.iov_base, | |
1454 | iovec.iov_len, behavior); | |
1455 | if (ret < 0) | |
1456 | break; | |
1457 | iov_iter_advance(&iter, iovec.iov_len); | |
1458 | } | |
1459 | ||
1460 | if (ret == 0) | |
1461 | ret = total_len - iov_iter_count(&iter); | |
1462 | ||
96cfe2c0 | 1463 | release_mm: |
ecb8ac8b | 1464 | mmput(mm); |
ecb8ac8b MK |
1465 | release_task: |
1466 | put_task_struct(task); | |
ecb8ac8b MK |
1467 | free_iov: |
1468 | kfree(iov); | |
1469 | out: | |
1470 | return ret; | |
1471 | } |