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: | |
9457056a | 55 | case MADV_DONTNEED_LOCKED: |
9c276cc6 | 56 | case MADV_COLD: |
1a4e58cc | 57 | case MADV_PAGEOUT: |
854e9ed0 | 58 | case MADV_FREE: |
4ca9b385 DH |
59 | case MADV_POPULATE_READ: |
60 | case MADV_POPULATE_WRITE: | |
0a27a14a NP |
61 | return 0; |
62 | default: | |
63 | /* be safe, default to 1. list exceptions explicitly */ | |
64 | return 1; | |
65 | } | |
66 | } | |
67 | ||
9a10064f | 68 | #ifdef CONFIG_ANON_VMA_NAME |
5c26f6ac | 69 | struct anon_vma_name *anon_vma_name_alloc(const char *name) |
78db3412 SB |
70 | { |
71 | struct anon_vma_name *anon_name; | |
72 | size_t count; | |
73 | ||
74 | /* Add 1 for NUL terminator at the end of the anon_name->name */ | |
75 | count = strlen(name) + 1; | |
76 | anon_name = kmalloc(struct_size(anon_name, name, count), GFP_KERNEL); | |
77 | if (anon_name) { | |
78 | kref_init(&anon_name->kref); | |
79 | memcpy(anon_name->name, name, count); | |
80 | } | |
81 | ||
82 | return anon_name; | |
83 | } | |
84 | ||
5c26f6ac | 85 | void anon_vma_name_free(struct kref *kref) |
78db3412 SB |
86 | { |
87 | struct anon_vma_name *anon_name = | |
88 | container_of(kref, struct anon_vma_name, kref); | |
89 | kfree(anon_name); | |
90 | } | |
91 | ||
5c26f6ac | 92 | struct anon_vma_name *anon_vma_name(struct vm_area_struct *vma) |
9a10064f | 93 | { |
9a10064f CC |
94 | mmap_assert_locked(vma->vm_mm); |
95 | ||
5c26f6ac SB |
96 | if (vma->vm_file) |
97 | return NULL; | |
9a10064f | 98 | |
5c26f6ac | 99 | return vma->anon_name; |
9a10064f CC |
100 | } |
101 | ||
102 | /* mmap_lock should be write-locked */ | |
5c26f6ac SB |
103 | static int replace_anon_vma_name(struct vm_area_struct *vma, |
104 | struct anon_vma_name *anon_name) | |
9a10064f | 105 | { |
5c26f6ac | 106 | struct anon_vma_name *orig_name = anon_vma_name(vma); |
78db3412 | 107 | |
5c26f6ac SB |
108 | if (!anon_name) { |
109 | vma->anon_name = NULL; | |
110 | anon_vma_name_put(orig_name); | |
9a10064f CC |
111 | return 0; |
112 | } | |
113 | ||
5c26f6ac SB |
114 | if (anon_vma_name_eq(orig_name, anon_name)) |
115 | return 0; | |
9a10064f | 116 | |
96403e11 | 117 | vma->anon_name = anon_vma_name_reuse(anon_name); |
5c26f6ac | 118 | anon_vma_name_put(orig_name); |
9a10064f CC |
119 | |
120 | return 0; | |
121 | } | |
122 | #else /* CONFIG_ANON_VMA_NAME */ | |
5c26f6ac SB |
123 | static int replace_anon_vma_name(struct vm_area_struct *vma, |
124 | struct anon_vma_name *anon_name) | |
9a10064f | 125 | { |
5c26f6ac | 126 | if (anon_name) |
9a10064f CC |
127 | return -EINVAL; |
128 | ||
129 | return 0; | |
130 | } | |
131 | #endif /* CONFIG_ANON_VMA_NAME */ | |
1da177e4 | 132 | /* |
ac1e9acc CC |
133 | * Update the vm_flags on region of a vma, splitting it or merging it as |
134 | * necessary. Must be called with mmap_sem held for writing; | |
942341dc SB |
135 | * Caller should ensure anon_name stability by raising its refcount even when |
136 | * anon_name belongs to a valid vma because this function might free that vma. | |
1da177e4 | 137 | */ |
ac1e9acc CC |
138 | static int madvise_update_vma(struct vm_area_struct *vma, |
139 | struct vm_area_struct **prev, unsigned long start, | |
9a10064f | 140 | unsigned long end, unsigned long new_flags, |
5c26f6ac | 141 | struct anon_vma_name *anon_name) |
1da177e4 | 142 | { |
ec9bed9d | 143 | struct mm_struct *mm = vma->vm_mm; |
ac1e9acc | 144 | int error; |
05b74384 | 145 | pgoff_t pgoff; |
e798c6e8 | 146 | |
5c26f6ac | 147 | if (new_flags == vma->vm_flags && anon_vma_name_eq(anon_vma_name(vma), anon_name)) { |
05b74384 | 148 | *prev = vma; |
ac1e9acc | 149 | return 0; |
05b74384 PM |
150 | } |
151 | ||
152 | pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); | |
153 | *prev = vma_merge(mm, *prev, start, end, new_flags, vma->anon_vma, | |
19a809af | 154 | vma->vm_file, pgoff, vma_policy(vma), |
5c26f6ac | 155 | vma->vm_userfaultfd_ctx, anon_name); |
05b74384 PM |
156 | if (*prev) { |
157 | vma = *prev; | |
158 | goto success; | |
159 | } | |
160 | ||
161 | *prev = vma; | |
1da177e4 LT |
162 | |
163 | if (start != vma->vm_start) { | |
ac1e9acc CC |
164 | if (unlikely(mm->map_count >= sysctl_max_map_count)) |
165 | return -ENOMEM; | |
def5efe0 | 166 | error = __split_vma(mm, vma, start, 1); |
f3bc0dba | 167 | if (error) |
ac1e9acc | 168 | return error; |
1da177e4 LT |
169 | } |
170 | ||
171 | if (end != vma->vm_end) { | |
ac1e9acc CC |
172 | if (unlikely(mm->map_count >= sysctl_max_map_count)) |
173 | return -ENOMEM; | |
def5efe0 | 174 | error = __split_vma(mm, vma, end, 0); |
f3bc0dba | 175 | if (error) |
ac1e9acc | 176 | return error; |
1da177e4 LT |
177 | } |
178 | ||
836d5ffd | 179 | success: |
1da177e4 | 180 | /* |
c1e8d7c6 | 181 | * vm_flags is protected by the mmap_lock held in write mode. |
1da177e4 | 182 | */ |
e798c6e8 | 183 | vma->vm_flags = new_flags; |
9a10064f | 184 | if (!vma->vm_file) { |
5c26f6ac | 185 | error = replace_anon_vma_name(vma, anon_name); |
9a10064f CC |
186 | if (error) |
187 | return error; | |
188 | } | |
f3bc0dba | 189 | |
ac1e9acc | 190 | return 0; |
1da177e4 LT |
191 | } |
192 | ||
1998cc04 SL |
193 | #ifdef CONFIG_SWAP |
194 | static int swapin_walk_pmd_entry(pmd_t *pmd, unsigned long start, | |
195 | unsigned long end, struct mm_walk *walk) | |
196 | { | |
197 | pte_t *orig_pte; | |
198 | struct vm_area_struct *vma = walk->private; | |
199 | unsigned long index; | |
200 | ||
201 | if (pmd_none_or_trans_huge_or_clear_bad(pmd)) | |
202 | return 0; | |
203 | ||
204 | for (index = start; index != end; index += PAGE_SIZE) { | |
205 | pte_t pte; | |
206 | swp_entry_t entry; | |
207 | struct page *page; | |
208 | spinlock_t *ptl; | |
209 | ||
210 | orig_pte = pte_offset_map_lock(vma->vm_mm, pmd, start, &ptl); | |
211 | pte = *(orig_pte + ((index - start) / PAGE_SIZE)); | |
212 | pte_unmap_unlock(orig_pte, ptl); | |
213 | ||
0661a336 | 214 | if (pte_present(pte) || pte_none(pte)) |
1998cc04 SL |
215 | continue; |
216 | entry = pte_to_swp_entry(pte); | |
217 | if (unlikely(non_swap_entry(entry))) | |
218 | continue; | |
219 | ||
220 | page = read_swap_cache_async(entry, GFP_HIGHUSER_MOVABLE, | |
23955622 | 221 | vma, index, false); |
1998cc04 | 222 | if (page) |
09cbfeaf | 223 | put_page(page); |
1998cc04 SL |
224 | } |
225 | ||
226 | return 0; | |
227 | } | |
228 | ||
7b86ac33 CH |
229 | static const struct mm_walk_ops swapin_walk_ops = { |
230 | .pmd_entry = swapin_walk_pmd_entry, | |
231 | }; | |
1998cc04 SL |
232 | |
233 | static void force_shm_swapin_readahead(struct vm_area_struct *vma, | |
234 | unsigned long start, unsigned long end, | |
235 | struct address_space *mapping) | |
236 | { | |
e6e88712 | 237 | XA_STATE(xas, &mapping->i_pages, linear_page_index(vma, start)); |
66383800 | 238 | pgoff_t end_index = linear_page_index(vma, end + PAGE_SIZE - 1); |
1998cc04 | 239 | struct page *page; |
1998cc04 | 240 | |
e6e88712 MWO |
241 | rcu_read_lock(); |
242 | xas_for_each(&xas, page, end_index) { | |
243 | swp_entry_t swap; | |
1998cc04 | 244 | |
e6e88712 | 245 | if (!xa_is_value(page)) |
1998cc04 | 246 | continue; |
e6e88712 MWO |
247 | xas_pause(&xas); |
248 | rcu_read_unlock(); | |
249 | ||
1998cc04 SL |
250 | swap = radix_to_swp_entry(page); |
251 | page = read_swap_cache_async(swap, GFP_HIGHUSER_MOVABLE, | |
23955622 | 252 | NULL, 0, false); |
1998cc04 | 253 | if (page) |
09cbfeaf | 254 | put_page(page); |
e6e88712 MWO |
255 | |
256 | rcu_read_lock(); | |
1998cc04 | 257 | } |
e6e88712 | 258 | rcu_read_unlock(); |
1998cc04 SL |
259 | |
260 | lru_add_drain(); /* Push any new pages onto the LRU now */ | |
261 | } | |
262 | #endif /* CONFIG_SWAP */ | |
263 | ||
1da177e4 LT |
264 | /* |
265 | * Schedule all required I/O operations. Do not wait for completion. | |
266 | */ | |
ec9bed9d VC |
267 | static long madvise_willneed(struct vm_area_struct *vma, |
268 | struct vm_area_struct **prev, | |
1da177e4 LT |
269 | unsigned long start, unsigned long end) |
270 | { | |
0726b01e | 271 | struct mm_struct *mm = vma->vm_mm; |
1da177e4 | 272 | struct file *file = vma->vm_file; |
692fe624 | 273 | loff_t offset; |
1da177e4 | 274 | |
6ea8d958 | 275 | *prev = vma; |
1998cc04 | 276 | #ifdef CONFIG_SWAP |
97b713ba | 277 | if (!file) { |
7b86ac33 CH |
278 | walk_page_range(vma->vm_mm, start, end, &swapin_walk_ops, vma); |
279 | lru_add_drain(); /* Push any new pages onto the LRU now */ | |
1998cc04 SL |
280 | return 0; |
281 | } | |
1998cc04 | 282 | |
97b713ba | 283 | if (shmem_mapping(file->f_mapping)) { |
97b713ba CH |
284 | force_shm_swapin_readahead(vma, start, end, |
285 | file->f_mapping); | |
286 | return 0; | |
287 | } | |
288 | #else | |
1bef4003 S |
289 | if (!file) |
290 | return -EBADF; | |
97b713ba | 291 | #endif |
1bef4003 | 292 | |
e748dcd0 | 293 | if (IS_DAX(file_inode(file))) { |
fe77ba6f CO |
294 | /* no bad return value, but ignore advice */ |
295 | return 0; | |
296 | } | |
297 | ||
692fe624 JK |
298 | /* |
299 | * Filesystem's fadvise may need to take various locks. We need to | |
300 | * explicitly grab a reference because the vma (and hence the | |
301 | * vma's reference to the file) can go away as soon as we drop | |
c1e8d7c6 | 302 | * mmap_lock. |
692fe624 | 303 | */ |
c1e8d7c6 | 304 | *prev = NULL; /* tell sys_madvise we drop mmap_lock */ |
692fe624 | 305 | get_file(file); |
692fe624 JK |
306 | offset = (loff_t)(start - vma->vm_start) |
307 | + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); | |
0726b01e | 308 | mmap_read_unlock(mm); |
692fe624 JK |
309 | vfs_fadvise(file, offset, end - start, POSIX_FADV_WILLNEED); |
310 | fput(file); | |
0726b01e | 311 | mmap_read_lock(mm); |
1da177e4 LT |
312 | return 0; |
313 | } | |
314 | ||
d616d512 MK |
315 | static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, |
316 | unsigned long addr, unsigned long end, | |
317 | struct mm_walk *walk) | |
9c276cc6 | 318 | { |
d616d512 MK |
319 | struct madvise_walk_private *private = walk->private; |
320 | struct mmu_gather *tlb = private->tlb; | |
321 | bool pageout = private->pageout; | |
9c276cc6 MK |
322 | struct mm_struct *mm = tlb->mm; |
323 | struct vm_area_struct *vma = walk->vma; | |
324 | pte_t *orig_pte, *pte, ptent; | |
325 | spinlock_t *ptl; | |
d616d512 MK |
326 | struct page *page = NULL; |
327 | LIST_HEAD(page_list); | |
328 | ||
329 | if (fatal_signal_pending(current)) | |
330 | return -EINTR; | |
9c276cc6 MK |
331 | |
332 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE | |
333 | if (pmd_trans_huge(*pmd)) { | |
334 | pmd_t orig_pmd; | |
335 | unsigned long next = pmd_addr_end(addr, end); | |
336 | ||
337 | tlb_change_page_size(tlb, HPAGE_PMD_SIZE); | |
338 | ptl = pmd_trans_huge_lock(pmd, vma); | |
339 | if (!ptl) | |
340 | return 0; | |
341 | ||
342 | orig_pmd = *pmd; | |
343 | if (is_huge_zero_pmd(orig_pmd)) | |
344 | goto huge_unlock; | |
345 | ||
346 | if (unlikely(!pmd_present(orig_pmd))) { | |
347 | VM_BUG_ON(thp_migration_supported() && | |
348 | !is_pmd_migration_entry(orig_pmd)); | |
349 | goto huge_unlock; | |
350 | } | |
351 | ||
352 | page = pmd_page(orig_pmd); | |
12e967fd MH |
353 | |
354 | /* Do not interfere with other mappings of this page */ | |
355 | if (page_mapcount(page) != 1) | |
356 | goto huge_unlock; | |
357 | ||
9c276cc6 MK |
358 | if (next - addr != HPAGE_PMD_SIZE) { |
359 | int err; | |
360 | ||
9c276cc6 MK |
361 | get_page(page); |
362 | spin_unlock(ptl); | |
363 | lock_page(page); | |
364 | err = split_huge_page(page); | |
365 | unlock_page(page); | |
366 | put_page(page); | |
367 | if (!err) | |
368 | goto regular_page; | |
369 | return 0; | |
370 | } | |
371 | ||
372 | if (pmd_young(orig_pmd)) { | |
373 | pmdp_invalidate(vma, addr, pmd); | |
374 | orig_pmd = pmd_mkold(orig_pmd); | |
375 | ||
376 | set_pmd_at(mm, addr, pmd, orig_pmd); | |
377 | tlb_remove_pmd_tlb_entry(tlb, pmd, addr); | |
378 | } | |
379 | ||
d616d512 | 380 | ClearPageReferenced(page); |
9c276cc6 | 381 | test_and_clear_page_young(page); |
d616d512 | 382 | if (pageout) { |
82072962 | 383 | if (!isolate_lru_page(page)) { |
384 | if (PageUnevictable(page)) | |
385 | putback_lru_page(page); | |
386 | else | |
387 | list_add(&page->lru, &page_list); | |
388 | } | |
d616d512 MK |
389 | } else |
390 | deactivate_page(page); | |
9c276cc6 MK |
391 | huge_unlock: |
392 | spin_unlock(ptl); | |
d616d512 MK |
393 | if (pageout) |
394 | reclaim_pages(&page_list); | |
9c276cc6 MK |
395 | return 0; |
396 | } | |
397 | ||
ce268425 | 398 | regular_page: |
9c276cc6 MK |
399 | if (pmd_trans_unstable(pmd)) |
400 | return 0; | |
9c276cc6 MK |
401 | #endif |
402 | tlb_change_page_size(tlb, PAGE_SIZE); | |
403 | orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
404 | flush_tlb_batched_pending(mm); | |
405 | arch_enter_lazy_mmu_mode(); | |
406 | for (; addr < end; pte++, addr += PAGE_SIZE) { | |
407 | ptent = *pte; | |
408 | ||
409 | if (pte_none(ptent)) | |
410 | continue; | |
411 | ||
412 | if (!pte_present(ptent)) | |
413 | continue; | |
414 | ||
415 | page = vm_normal_page(vma, addr, ptent); | |
416 | if (!page) | |
417 | continue; | |
418 | ||
419 | /* | |
420 | * Creating a THP page is expensive so split it only if we | |
421 | * are sure it's worth. Split it if we are only owner. | |
422 | */ | |
423 | if (PageTransCompound(page)) { | |
424 | if (page_mapcount(page) != 1) | |
425 | break; | |
426 | get_page(page); | |
427 | if (!trylock_page(page)) { | |
428 | put_page(page); | |
429 | break; | |
430 | } | |
431 | pte_unmap_unlock(orig_pte, ptl); | |
432 | if (split_huge_page(page)) { | |
433 | unlock_page(page); | |
434 | put_page(page); | |
435 | pte_offset_map_lock(mm, pmd, addr, &ptl); | |
436 | break; | |
437 | } | |
438 | unlock_page(page); | |
439 | put_page(page); | |
440 | pte = pte_offset_map_lock(mm, pmd, addr, &ptl); | |
441 | pte--; | |
442 | addr -= PAGE_SIZE; | |
443 | continue; | |
444 | } | |
445 | ||
12e967fd MH |
446 | /* Do not interfere with other mappings of this page */ |
447 | if (page_mapcount(page) != 1) | |
448 | continue; | |
449 | ||
9c276cc6 MK |
450 | VM_BUG_ON_PAGE(PageTransCompound(page), page); |
451 | ||
452 | if (pte_young(ptent)) { | |
453 | ptent = ptep_get_and_clear_full(mm, addr, pte, | |
454 | tlb->fullmm); | |
455 | ptent = pte_mkold(ptent); | |
456 | set_pte_at(mm, addr, pte, ptent); | |
457 | tlb_remove_tlb_entry(tlb, pte, addr); | |
458 | } | |
459 | ||
460 | /* | |
461 | * We are deactivating a page for accelerating reclaiming. | |
462 | * VM couldn't reclaim the page unless we clear PG_young. | |
463 | * As a side effect, it makes confuse idle-page tracking | |
464 | * because they will miss recent referenced history. | |
465 | */ | |
d616d512 | 466 | ClearPageReferenced(page); |
9c276cc6 | 467 | test_and_clear_page_young(page); |
d616d512 | 468 | if (pageout) { |
82072962 | 469 | if (!isolate_lru_page(page)) { |
470 | if (PageUnevictable(page)) | |
471 | putback_lru_page(page); | |
472 | else | |
473 | list_add(&page->lru, &page_list); | |
474 | } | |
d616d512 MK |
475 | } else |
476 | deactivate_page(page); | |
9c276cc6 MK |
477 | } |
478 | ||
479 | arch_leave_lazy_mmu_mode(); | |
480 | pte_unmap_unlock(orig_pte, ptl); | |
d616d512 MK |
481 | if (pageout) |
482 | reclaim_pages(&page_list); | |
9c276cc6 MK |
483 | cond_resched(); |
484 | ||
485 | return 0; | |
486 | } | |
487 | ||
488 | static const struct mm_walk_ops cold_walk_ops = { | |
d616d512 | 489 | .pmd_entry = madvise_cold_or_pageout_pte_range, |
9c276cc6 MK |
490 | }; |
491 | ||
492 | static void madvise_cold_page_range(struct mmu_gather *tlb, | |
493 | struct vm_area_struct *vma, | |
494 | unsigned long addr, unsigned long end) | |
495 | { | |
d616d512 MK |
496 | struct madvise_walk_private walk_private = { |
497 | .pageout = false, | |
498 | .tlb = tlb, | |
499 | }; | |
500 | ||
9c276cc6 | 501 | tlb_start_vma(tlb, vma); |
d616d512 | 502 | walk_page_range(vma->vm_mm, addr, end, &cold_walk_ops, &walk_private); |
9c276cc6 MK |
503 | tlb_end_vma(tlb, vma); |
504 | } | |
505 | ||
a213e5cf HD |
506 | static inline bool can_madv_lru_vma(struct vm_area_struct *vma) |
507 | { | |
9457056a | 508 | return !(vma->vm_flags & (VM_LOCKED|VM_PFNMAP|VM_HUGETLB)); |
a213e5cf HD |
509 | } |
510 | ||
9c276cc6 MK |
511 | static long madvise_cold(struct vm_area_struct *vma, |
512 | struct vm_area_struct **prev, | |
513 | unsigned long start_addr, unsigned long end_addr) | |
514 | { | |
515 | struct mm_struct *mm = vma->vm_mm; | |
516 | struct mmu_gather tlb; | |
517 | ||
518 | *prev = vma; | |
519 | if (!can_madv_lru_vma(vma)) | |
520 | return -EINVAL; | |
521 | ||
522 | lru_add_drain(); | |
a72afd87 | 523 | tlb_gather_mmu(&tlb, mm); |
9c276cc6 | 524 | madvise_cold_page_range(&tlb, vma, start_addr, end_addr); |
ae8eba8b | 525 | tlb_finish_mmu(&tlb); |
9c276cc6 MK |
526 | |
527 | return 0; | |
528 | } | |
529 | ||
1a4e58cc MK |
530 | static void madvise_pageout_page_range(struct mmu_gather *tlb, |
531 | struct vm_area_struct *vma, | |
532 | unsigned long addr, unsigned long end) | |
533 | { | |
d616d512 MK |
534 | struct madvise_walk_private walk_private = { |
535 | .pageout = true, | |
536 | .tlb = tlb, | |
537 | }; | |
538 | ||
1a4e58cc | 539 | tlb_start_vma(tlb, vma); |
d616d512 | 540 | walk_page_range(vma->vm_mm, addr, end, &cold_walk_ops, &walk_private); |
1a4e58cc MK |
541 | tlb_end_vma(tlb, vma); |
542 | } | |
543 | ||
544 | static inline bool can_do_pageout(struct vm_area_struct *vma) | |
545 | { | |
546 | if (vma_is_anonymous(vma)) | |
547 | return true; | |
548 | if (!vma->vm_file) | |
549 | return false; | |
550 | /* | |
551 | * paging out pagecache only for non-anonymous mappings that correspond | |
552 | * to the files the calling process could (if tried) open for writing; | |
553 | * otherwise we'd be including shared non-exclusive mappings, which | |
554 | * opens a side channel. | |
555 | */ | |
21cb47be CB |
556 | return inode_owner_or_capable(&init_user_ns, |
557 | file_inode(vma->vm_file)) || | |
02f92b38 | 558 | file_permission(vma->vm_file, MAY_WRITE) == 0; |
1a4e58cc MK |
559 | } |
560 | ||
561 | static long madvise_pageout(struct vm_area_struct *vma, | |
562 | struct vm_area_struct **prev, | |
563 | unsigned long start_addr, unsigned long end_addr) | |
564 | { | |
565 | struct mm_struct *mm = vma->vm_mm; | |
566 | struct mmu_gather tlb; | |
567 | ||
568 | *prev = vma; | |
569 | if (!can_madv_lru_vma(vma)) | |
570 | return -EINVAL; | |
571 | ||
572 | if (!can_do_pageout(vma)) | |
573 | return 0; | |
574 | ||
575 | lru_add_drain(); | |
a72afd87 | 576 | tlb_gather_mmu(&tlb, mm); |
1a4e58cc | 577 | madvise_pageout_page_range(&tlb, vma, start_addr, end_addr); |
ae8eba8b | 578 | tlb_finish_mmu(&tlb); |
1a4e58cc MK |
579 | |
580 | return 0; | |
581 | } | |
582 | ||
854e9ed0 MK |
583 | static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr, |
584 | unsigned long end, struct mm_walk *walk) | |
585 | ||
586 | { | |
587 | struct mmu_gather *tlb = walk->private; | |
588 | struct mm_struct *mm = tlb->mm; | |
589 | struct vm_area_struct *vma = walk->vma; | |
590 | spinlock_t *ptl; | |
591 | pte_t *orig_pte, *pte, ptent; | |
592 | struct page *page; | |
64b42bc1 | 593 | int nr_swap = 0; |
b8d3c4c3 MK |
594 | unsigned long next; |
595 | ||
596 | next = pmd_addr_end(addr, end); | |
597 | if (pmd_trans_huge(*pmd)) | |
598 | if (madvise_free_huge_pmd(tlb, vma, pmd, addr, next)) | |
599 | goto next; | |
854e9ed0 | 600 | |
854e9ed0 MK |
601 | if (pmd_trans_unstable(pmd)) |
602 | return 0; | |
603 | ||
ed6a7935 | 604 | tlb_change_page_size(tlb, PAGE_SIZE); |
854e9ed0 | 605 | orig_pte = pte = pte_offset_map_lock(mm, pmd, addr, &ptl); |
3ea27719 | 606 | flush_tlb_batched_pending(mm); |
854e9ed0 MK |
607 | arch_enter_lazy_mmu_mode(); |
608 | for (; addr != end; pte++, addr += PAGE_SIZE) { | |
609 | ptent = *pte; | |
610 | ||
64b42bc1 | 611 | if (pte_none(ptent)) |
854e9ed0 | 612 | continue; |
64b42bc1 MK |
613 | /* |
614 | * If the pte has swp_entry, just clear page table to | |
615 | * prevent swap-in which is more expensive rather than | |
616 | * (page allocation + zeroing). | |
617 | */ | |
618 | if (!pte_present(ptent)) { | |
619 | swp_entry_t entry; | |
620 | ||
621 | entry = pte_to_swp_entry(ptent); | |
622 | if (non_swap_entry(entry)) | |
623 | continue; | |
624 | nr_swap--; | |
625 | free_swap_and_cache(entry); | |
626 | pte_clear_not_present_full(mm, addr, pte, tlb->fullmm); | |
627 | continue; | |
628 | } | |
854e9ed0 | 629 | |
25b2995a | 630 | page = vm_normal_page(vma, addr, ptent); |
854e9ed0 MK |
631 | if (!page) |
632 | continue; | |
633 | ||
634 | /* | |
635 | * If pmd isn't transhuge but the page is THP and | |
636 | * is owned by only this process, split it and | |
637 | * deactivate all pages. | |
638 | */ | |
639 | if (PageTransCompound(page)) { | |
640 | if (page_mapcount(page) != 1) | |
641 | goto out; | |
642 | get_page(page); | |
643 | if (!trylock_page(page)) { | |
644 | put_page(page); | |
645 | goto out; | |
646 | } | |
647 | pte_unmap_unlock(orig_pte, ptl); | |
648 | if (split_huge_page(page)) { | |
649 | unlock_page(page); | |
650 | put_page(page); | |
651 | pte_offset_map_lock(mm, pmd, addr, &ptl); | |
652 | goto out; | |
653 | } | |
854e9ed0 | 654 | unlock_page(page); |
263630e8 | 655 | put_page(page); |
854e9ed0 MK |
656 | pte = pte_offset_map_lock(mm, pmd, addr, &ptl); |
657 | pte--; | |
658 | addr -= PAGE_SIZE; | |
659 | continue; | |
660 | } | |
661 | ||
662 | VM_BUG_ON_PAGE(PageTransCompound(page), page); | |
663 | ||
664 | if (PageSwapCache(page) || PageDirty(page)) { | |
665 | if (!trylock_page(page)) | |
666 | continue; | |
667 | /* | |
668 | * If page is shared with others, we couldn't clear | |
669 | * PG_dirty of the page. | |
670 | */ | |
671 | if (page_mapcount(page) != 1) { | |
672 | unlock_page(page); | |
673 | continue; | |
674 | } | |
675 | ||
676 | if (PageSwapCache(page) && !try_to_free_swap(page)) { | |
677 | unlock_page(page); | |
678 | continue; | |
679 | } | |
680 | ||
681 | ClearPageDirty(page); | |
682 | unlock_page(page); | |
683 | } | |
684 | ||
685 | if (pte_young(ptent) || pte_dirty(ptent)) { | |
686 | /* | |
687 | * Some of architecture(ex, PPC) don't update TLB | |
688 | * with set_pte_at and tlb_remove_tlb_entry so for | |
689 | * the portability, remap the pte with old|clean | |
690 | * after pte clearing. | |
691 | */ | |
692 | ptent = ptep_get_and_clear_full(mm, addr, pte, | |
693 | tlb->fullmm); | |
694 | ||
695 | ptent = pte_mkold(ptent); | |
696 | ptent = pte_mkclean(ptent); | |
697 | set_pte_at(mm, addr, pte, ptent); | |
698 | tlb_remove_tlb_entry(tlb, pte, addr); | |
699 | } | |
802a3a92 | 700 | mark_page_lazyfree(page); |
854e9ed0 MK |
701 | } |
702 | out: | |
64b42bc1 MK |
703 | if (nr_swap) { |
704 | if (current->mm == mm) | |
705 | sync_mm_rss(mm); | |
706 | ||
707 | add_mm_counter(mm, MM_SWAPENTS, nr_swap); | |
708 | } | |
854e9ed0 MK |
709 | arch_leave_lazy_mmu_mode(); |
710 | pte_unmap_unlock(orig_pte, ptl); | |
711 | cond_resched(); | |
b8d3c4c3 | 712 | next: |
854e9ed0 MK |
713 | return 0; |
714 | } | |
715 | ||
7b86ac33 CH |
716 | static const struct mm_walk_ops madvise_free_walk_ops = { |
717 | .pmd_entry = madvise_free_pte_range, | |
718 | }; | |
854e9ed0 MK |
719 | |
720 | static int madvise_free_single_vma(struct vm_area_struct *vma, | |
721 | unsigned long start_addr, unsigned long end_addr) | |
722 | { | |
854e9ed0 | 723 | struct mm_struct *mm = vma->vm_mm; |
ac46d4f3 | 724 | struct mmu_notifier_range range; |
854e9ed0 MK |
725 | struct mmu_gather tlb; |
726 | ||
854e9ed0 MK |
727 | /* MADV_FREE works for only anon vma at the moment */ |
728 | if (!vma_is_anonymous(vma)) | |
729 | return -EINVAL; | |
730 | ||
ac46d4f3 JG |
731 | range.start = max(vma->vm_start, start_addr); |
732 | if (range.start >= vma->vm_end) | |
854e9ed0 | 733 | return -EINVAL; |
ac46d4f3 JG |
734 | range.end = min(vma->vm_end, end_addr); |
735 | if (range.end <= vma->vm_start) | |
854e9ed0 | 736 | return -EINVAL; |
7269f999 | 737 | mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, |
6f4f13e8 | 738 | range.start, range.end); |
854e9ed0 MK |
739 | |
740 | lru_add_drain(); | |
a72afd87 | 741 | tlb_gather_mmu(&tlb, mm); |
854e9ed0 MK |
742 | update_hiwater_rss(mm); |
743 | ||
ac46d4f3 | 744 | mmu_notifier_invalidate_range_start(&range); |
7b86ac33 CH |
745 | tlb_start_vma(&tlb, vma); |
746 | walk_page_range(vma->vm_mm, range.start, range.end, | |
747 | &madvise_free_walk_ops, &tlb); | |
748 | tlb_end_vma(&tlb, vma); | |
ac46d4f3 | 749 | mmu_notifier_invalidate_range_end(&range); |
ae8eba8b | 750 | tlb_finish_mmu(&tlb); |
854e9ed0 MK |
751 | |
752 | return 0; | |
753 | } | |
754 | ||
1da177e4 LT |
755 | /* |
756 | * Application no longer needs these pages. If the pages are dirty, | |
757 | * it's OK to just throw them away. The app will be more careful about | |
758 | * data it wants to keep. Be sure to free swap resources too. The | |
7e6cbea3 | 759 | * zap_page_range call sets things up for shrink_active_list to actually free |
1da177e4 LT |
760 | * these pages later if no one else has touched them in the meantime, |
761 | * although we could add these pages to a global reuse list for | |
7e6cbea3 | 762 | * shrink_active_list to pick up before reclaiming other pages. |
1da177e4 LT |
763 | * |
764 | * NB: This interface discards data rather than pushes it out to swap, | |
765 | * as some implementations do. This has performance implications for | |
766 | * applications like large transactional databases which want to discard | |
767 | * pages in anonymous maps after committing to backing store the data | |
768 | * that was kept in them. There is no reason to write this data out to | |
769 | * the swap area if the application is discarding it. | |
770 | * | |
771 | * An interface that causes the system to free clean pages and flush | |
772 | * dirty pages is already available as msync(MS_INVALIDATE). | |
773 | */ | |
230ca982 MR |
774 | static long madvise_dontneed_single_vma(struct vm_area_struct *vma, |
775 | unsigned long start, unsigned long end) | |
776 | { | |
777 | zap_page_range(vma, start, end - start); | |
778 | return 0; | |
779 | } | |
780 | ||
90e7e7f5 MK |
781 | static bool madvise_dontneed_free_valid_vma(struct vm_area_struct *vma, |
782 | unsigned long start, | |
783 | unsigned long *end, | |
784 | int behavior) | |
785 | { | |
9457056a JW |
786 | if (!is_vm_hugetlb_page(vma)) { |
787 | unsigned int forbidden = VM_PFNMAP; | |
788 | ||
789 | if (behavior != MADV_DONTNEED_LOCKED) | |
790 | forbidden |= VM_LOCKED; | |
791 | ||
792 | return !(vma->vm_flags & forbidden); | |
793 | } | |
90e7e7f5 | 794 | |
9457056a | 795 | if (behavior != MADV_DONTNEED && behavior != MADV_DONTNEED_LOCKED) |
90e7e7f5 MK |
796 | return false; |
797 | if (start & ~huge_page_mask(hstate_vma(vma))) | |
798 | return false; | |
799 | ||
800 | *end = ALIGN(*end, huge_page_size(hstate_vma(vma))); | |
801 | return true; | |
802 | } | |
803 | ||
230ca982 MR |
804 | static long madvise_dontneed_free(struct vm_area_struct *vma, |
805 | struct vm_area_struct **prev, | |
806 | unsigned long start, unsigned long end, | |
807 | int behavior) | |
1da177e4 | 808 | { |
0726b01e MK |
809 | struct mm_struct *mm = vma->vm_mm; |
810 | ||
05b74384 | 811 | *prev = vma; |
90e7e7f5 | 812 | if (!madvise_dontneed_free_valid_vma(vma, start, &end, behavior)) |
1da177e4 LT |
813 | return -EINVAL; |
814 | ||
70ccb92f | 815 | if (!userfaultfd_remove(vma, start, end)) { |
c1e8d7c6 | 816 | *prev = NULL; /* mmap_lock has been dropped, prev is stale */ |
70ccb92f | 817 | |
0726b01e MK |
818 | mmap_read_lock(mm); |
819 | vma = find_vma(mm, start); | |
70ccb92f AA |
820 | if (!vma) |
821 | return -ENOMEM; | |
822 | if (start < vma->vm_start) { | |
823 | /* | |
824 | * This "vma" under revalidation is the one | |
825 | * with the lowest vma->vm_start where start | |
826 | * is also < vma->vm_end. If start < | |
827 | * vma->vm_start it means an hole materialized | |
828 | * in the user address space within the | |
230ca982 MR |
829 | * virtual range passed to MADV_DONTNEED |
830 | * or MADV_FREE. | |
70ccb92f AA |
831 | */ |
832 | return -ENOMEM; | |
833 | } | |
90e7e7f5 MK |
834 | /* |
835 | * Potential end adjustment for hugetlb vma is OK as | |
836 | * the check below keeps end within vma. | |
837 | */ | |
838 | if (!madvise_dontneed_free_valid_vma(vma, start, &end, | |
839 | behavior)) | |
70ccb92f AA |
840 | return -EINVAL; |
841 | if (end > vma->vm_end) { | |
842 | /* | |
843 | * Don't fail if end > vma->vm_end. If the old | |
f0953a1b | 844 | * vma was split while the mmap_lock was |
70ccb92f | 845 | * released the effect of the concurrent |
230ca982 | 846 | * operation may not cause madvise() to |
70ccb92f AA |
847 | * have an undefined result. There may be an |
848 | * adjacent next vma that we'll walk | |
849 | * next. userfaultfd_remove() will generate an | |
850 | * UFFD_EVENT_REMOVE repetition on the | |
851 | * end-vma->vm_end range, but the manager can | |
852 | * handle a repetition fine. | |
853 | */ | |
854 | end = vma->vm_end; | |
855 | } | |
856 | VM_WARN_ON(start >= end); | |
857 | } | |
230ca982 | 858 | |
9457056a | 859 | if (behavior == MADV_DONTNEED || behavior == MADV_DONTNEED_LOCKED) |
230ca982 MR |
860 | return madvise_dontneed_single_vma(vma, start, end); |
861 | else if (behavior == MADV_FREE) | |
862 | return madvise_free_single_vma(vma, start, end); | |
863 | else | |
864 | return -EINVAL; | |
1da177e4 LT |
865 | } |
866 | ||
4ca9b385 DH |
867 | static long madvise_populate(struct vm_area_struct *vma, |
868 | struct vm_area_struct **prev, | |
869 | unsigned long start, unsigned long end, | |
870 | int behavior) | |
871 | { | |
872 | const bool write = behavior == MADV_POPULATE_WRITE; | |
873 | struct mm_struct *mm = vma->vm_mm; | |
874 | unsigned long tmp_end; | |
875 | int locked = 1; | |
876 | long pages; | |
877 | ||
878 | *prev = vma; | |
879 | ||
880 | while (start < end) { | |
881 | /* | |
882 | * We might have temporarily dropped the lock. For example, | |
883 | * our VMA might have been split. | |
884 | */ | |
885 | if (!vma || start >= vma->vm_end) { | |
531037a0 ML |
886 | vma = vma_lookup(mm, start); |
887 | if (!vma) | |
4ca9b385 DH |
888 | return -ENOMEM; |
889 | } | |
890 | ||
891 | tmp_end = min_t(unsigned long, end, vma->vm_end); | |
892 | /* Populate (prefault) page tables readable/writable. */ | |
893 | pages = faultin_vma_page_range(vma, start, tmp_end, write, | |
894 | &locked); | |
895 | if (!locked) { | |
896 | mmap_read_lock(mm); | |
897 | locked = 1; | |
898 | *prev = NULL; | |
899 | vma = NULL; | |
900 | } | |
901 | if (pages < 0) { | |
902 | switch (pages) { | |
903 | case -EINTR: | |
904 | return -EINTR; | |
eb2faa51 | 905 | case -EINVAL: /* Incompatible mappings / permissions. */ |
4ca9b385 DH |
906 | return -EINVAL; |
907 | case -EHWPOISON: | |
908 | return -EHWPOISON; | |
eb2faa51 DH |
909 | case -EFAULT: /* VM_FAULT_SIGBUS or VM_FAULT_SIGSEGV */ |
910 | return -EFAULT; | |
4ca9b385 DH |
911 | default: |
912 | pr_warn_once("%s: unhandled return value: %ld\n", | |
913 | __func__, pages); | |
914 | fallthrough; | |
915 | case -ENOMEM: | |
916 | return -ENOMEM; | |
917 | } | |
918 | } | |
919 | start += pages * PAGE_SIZE; | |
920 | } | |
921 | return 0; | |
922 | } | |
923 | ||
f6b3ec23 BP |
924 | /* |
925 | * Application wants to free up the pages and associated backing store. | |
926 | * This is effectively punching a hole into the middle of a file. | |
f6b3ec23 BP |
927 | */ |
928 | static long madvise_remove(struct vm_area_struct *vma, | |
00e9fa2d | 929 | struct vm_area_struct **prev, |
f6b3ec23 BP |
930 | unsigned long start, unsigned long end) |
931 | { | |
3f31d075 | 932 | loff_t offset; |
90ed52eb | 933 | int error; |
9ab4233d | 934 | struct file *f; |
0726b01e | 935 | struct mm_struct *mm = vma->vm_mm; |
f6b3ec23 | 936 | |
c1e8d7c6 | 937 | *prev = NULL; /* tell sys_madvise we drop mmap_lock */ |
00e9fa2d | 938 | |
72079ba0 | 939 | if (vma->vm_flags & VM_LOCKED) |
f6b3ec23 BP |
940 | return -EINVAL; |
941 | ||
9ab4233d AL |
942 | f = vma->vm_file; |
943 | ||
944 | if (!f || !f->f_mapping || !f->f_mapping->host) { | |
f6b3ec23 BP |
945 | return -EINVAL; |
946 | } | |
947 | ||
69cf0fac HD |
948 | if ((vma->vm_flags & (VM_SHARED|VM_WRITE)) != (VM_SHARED|VM_WRITE)) |
949 | return -EACCES; | |
950 | ||
f6b3ec23 BP |
951 | offset = (loff_t)(start - vma->vm_start) |
952 | + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); | |
90ed52eb | 953 | |
9ab4233d | 954 | /* |
9608703e | 955 | * Filesystem's fallocate may need to take i_rwsem. We need to |
9ab4233d AL |
956 | * explicitly grab a reference because the vma (and hence the |
957 | * vma's reference to the file) can go away as soon as we drop | |
c1e8d7c6 | 958 | * mmap_lock. |
9ab4233d AL |
959 | */ |
960 | get_file(f); | |
70ccb92f | 961 | if (userfaultfd_remove(vma, start, end)) { |
c1e8d7c6 | 962 | /* mmap_lock was not released by userfaultfd_remove() */ |
0726b01e | 963 | mmap_read_unlock(mm); |
70ccb92f | 964 | } |
72c72bdf | 965 | error = vfs_fallocate(f, |
3f31d075 HD |
966 | FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, |
967 | offset, end - start); | |
9ab4233d | 968 | fput(f); |
0726b01e | 969 | mmap_read_lock(mm); |
90ed52eb | 970 | return error; |
f6b3ec23 BP |
971 | } |
972 | ||
ac1e9acc CC |
973 | /* |
974 | * Apply an madvise behavior to a region of a vma. madvise_update_vma | |
975 | * will handle splitting a vm area into separate areas, each area with its own | |
976 | * behavior. | |
977 | */ | |
978 | static int madvise_vma_behavior(struct vm_area_struct *vma, | |
979 | struct vm_area_struct **prev, | |
980 | unsigned long start, unsigned long end, | |
981 | unsigned long behavior) | |
982 | { | |
983 | int error; | |
942341dc | 984 | struct anon_vma_name *anon_name; |
ac1e9acc CC |
985 | unsigned long new_flags = vma->vm_flags; |
986 | ||
987 | switch (behavior) { | |
988 | case MADV_REMOVE: | |
989 | return madvise_remove(vma, prev, start, end); | |
990 | case MADV_WILLNEED: | |
991 | return madvise_willneed(vma, prev, start, end); | |
992 | case MADV_COLD: | |
993 | return madvise_cold(vma, prev, start, end); | |
994 | case MADV_PAGEOUT: | |
995 | return madvise_pageout(vma, prev, start, end); | |
996 | case MADV_FREE: | |
997 | case MADV_DONTNEED: | |
9457056a | 998 | case MADV_DONTNEED_LOCKED: |
ac1e9acc CC |
999 | return madvise_dontneed_free(vma, prev, start, end, behavior); |
1000 | case MADV_POPULATE_READ: | |
1001 | case MADV_POPULATE_WRITE: | |
1002 | return madvise_populate(vma, prev, start, end, behavior); | |
1003 | case MADV_NORMAL: | |
1004 | new_flags = new_flags & ~VM_RAND_READ & ~VM_SEQ_READ; | |
1005 | break; | |
1006 | case MADV_SEQUENTIAL: | |
1007 | new_flags = (new_flags & ~VM_RAND_READ) | VM_SEQ_READ; | |
1008 | break; | |
1009 | case MADV_RANDOM: | |
1010 | new_flags = (new_flags & ~VM_SEQ_READ) | VM_RAND_READ; | |
1011 | break; | |
1012 | case MADV_DONTFORK: | |
1013 | new_flags |= VM_DONTCOPY; | |
1014 | break; | |
1015 | case MADV_DOFORK: | |
1016 | if (vma->vm_flags & VM_IO) | |
1017 | return -EINVAL; | |
1018 | new_flags &= ~VM_DONTCOPY; | |
1019 | break; | |
1020 | case MADV_WIPEONFORK: | |
1021 | /* MADV_WIPEONFORK is only supported on anonymous memory. */ | |
1022 | if (vma->vm_file || vma->vm_flags & VM_SHARED) | |
1023 | return -EINVAL; | |
1024 | new_flags |= VM_WIPEONFORK; | |
1025 | break; | |
1026 | case MADV_KEEPONFORK: | |
1027 | new_flags &= ~VM_WIPEONFORK; | |
1028 | break; | |
1029 | case MADV_DONTDUMP: | |
1030 | new_flags |= VM_DONTDUMP; | |
1031 | break; | |
1032 | case MADV_DODUMP: | |
1033 | if (!is_vm_hugetlb_page(vma) && new_flags & VM_SPECIAL) | |
1034 | return -EINVAL; | |
1035 | new_flags &= ~VM_DONTDUMP; | |
1036 | break; | |
1037 | case MADV_MERGEABLE: | |
1038 | case MADV_UNMERGEABLE: | |
1039 | error = ksm_madvise(vma, start, end, behavior, &new_flags); | |
1040 | if (error) | |
1041 | goto out; | |
1042 | break; | |
1043 | case MADV_HUGEPAGE: | |
1044 | case MADV_NOHUGEPAGE: | |
1045 | error = hugepage_madvise(vma, &new_flags, behavior); | |
1046 | if (error) | |
1047 | goto out; | |
1048 | break; | |
1049 | } | |
1050 | ||
942341dc SB |
1051 | anon_name = anon_vma_name(vma); |
1052 | anon_vma_name_get(anon_name); | |
9a10064f | 1053 | error = madvise_update_vma(vma, prev, start, end, new_flags, |
942341dc SB |
1054 | anon_name); |
1055 | anon_vma_name_put(anon_name); | |
ac1e9acc CC |
1056 | |
1057 | out: | |
1058 | /* | |
1059 | * madvise() returns EAGAIN if kernel resources, such as | |
1060 | * slab, are temporarily unavailable. | |
1061 | */ | |
1062 | if (error == -ENOMEM) | |
1063 | error = -EAGAIN; | |
1064 | return error; | |
1065 | } | |
1066 | ||
9893e49d AK |
1067 | #ifdef CONFIG_MEMORY_FAILURE |
1068 | /* | |
1069 | * Error injection support for memory error handling. | |
1070 | */ | |
97167a76 AK |
1071 | static int madvise_inject_error(int behavior, |
1072 | unsigned long start, unsigned long end) | |
9893e49d | 1073 | { |
d3cd257c | 1074 | unsigned long size; |
97167a76 | 1075 | |
9893e49d AK |
1076 | if (!capable(CAP_SYS_ADMIN)) |
1077 | return -EPERM; | |
97167a76 | 1078 | |
19bfbe22 | 1079 | |
d3cd257c | 1080 | for (; start < end; start += size) { |
23e7b5c2 | 1081 | unsigned long pfn; |
dc7560b4 | 1082 | struct page *page; |
325c4ef5 AM |
1083 | int ret; |
1084 | ||
97167a76 | 1085 | ret = get_user_pages_fast(start, 1, 0, &page); |
9893e49d AK |
1086 | if (ret != 1) |
1087 | return ret; | |
23e7b5c2 | 1088 | pfn = page_to_pfn(page); |
325c4ef5 | 1089 | |
19bfbe22 AM |
1090 | /* |
1091 | * When soft offlining hugepages, after migrating the page | |
1092 | * we dissolve it, therefore in the second loop "page" will | |
d3cd257c | 1093 | * no longer be a compound page. |
19bfbe22 | 1094 | */ |
d3cd257c | 1095 | size = page_size(compound_head(page)); |
19bfbe22 | 1096 | |
97167a76 AK |
1097 | if (behavior == MADV_SOFT_OFFLINE) { |
1098 | pr_info("Soft offlining pfn %#lx at process virtual address %#lx\n", | |
dc7560b4 | 1099 | pfn, start); |
feec24a6 | 1100 | ret = soft_offline_page(pfn, MF_COUNT_INCREASED); |
dc7560b4 OS |
1101 | } else { |
1102 | pr_info("Injecting memory failure for pfn %#lx at process virtual address %#lx\n", | |
1103 | pfn, start); | |
1e8aaedb | 1104 | ret = memory_failure(pfn, MF_COUNT_INCREASED); |
d1fe111f | 1105 | if (ret == -EOPNOTSUPP) |
1106 | ret = 0; | |
afcf938e | 1107 | } |
23e7b5c2 | 1108 | |
23a003bf NH |
1109 | if (ret) |
1110 | return ret; | |
9893e49d | 1111 | } |
c461ad6a | 1112 | |
325c4ef5 | 1113 | return 0; |
9893e49d AK |
1114 | } |
1115 | #endif | |
1116 | ||
1ecef9ed | 1117 | static bool |
75927af8 NP |
1118 | madvise_behavior_valid(int behavior) |
1119 | { | |
1120 | switch (behavior) { | |
1121 | case MADV_DOFORK: | |
1122 | case MADV_DONTFORK: | |
1123 | case MADV_NORMAL: | |
1124 | case MADV_SEQUENTIAL: | |
1125 | case MADV_RANDOM: | |
1126 | case MADV_REMOVE: | |
1127 | case MADV_WILLNEED: | |
1128 | case MADV_DONTNEED: | |
9457056a | 1129 | case MADV_DONTNEED_LOCKED: |
854e9ed0 | 1130 | case MADV_FREE: |
9c276cc6 | 1131 | case MADV_COLD: |
1a4e58cc | 1132 | case MADV_PAGEOUT: |
4ca9b385 DH |
1133 | case MADV_POPULATE_READ: |
1134 | case MADV_POPULATE_WRITE: | |
f8af4da3 HD |
1135 | #ifdef CONFIG_KSM |
1136 | case MADV_MERGEABLE: | |
1137 | case MADV_UNMERGEABLE: | |
0af4e98b AA |
1138 | #endif |
1139 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE | |
1140 | case MADV_HUGEPAGE: | |
a664b2d8 | 1141 | case MADV_NOHUGEPAGE: |
f8af4da3 | 1142 | #endif |
accb61fe JB |
1143 | case MADV_DONTDUMP: |
1144 | case MADV_DODUMP: | |
d2cd9ede RR |
1145 | case MADV_WIPEONFORK: |
1146 | case MADV_KEEPONFORK: | |
5e451be7 AK |
1147 | #ifdef CONFIG_MEMORY_FAILURE |
1148 | case MADV_SOFT_OFFLINE: | |
1149 | case MADV_HWPOISON: | |
1150 | #endif | |
1ecef9ed | 1151 | return true; |
75927af8 NP |
1152 | |
1153 | default: | |
1ecef9ed | 1154 | return false; |
75927af8 NP |
1155 | } |
1156 | } | |
3866ea90 | 1157 | |
ecb8ac8b MK |
1158 | static bool |
1159 | process_madvise_behavior_valid(int behavior) | |
1160 | { | |
1161 | switch (behavior) { | |
1162 | case MADV_COLD: | |
1163 | case MADV_PAGEOUT: | |
d5fffc5a | 1164 | case MADV_WILLNEED: |
ecb8ac8b MK |
1165 | return true; |
1166 | default: | |
1167 | return false; | |
1168 | } | |
1169 | } | |
1170 | ||
ac1e9acc CC |
1171 | /* |
1172 | * Walk the vmas in range [start,end), and call the visit function on each one. | |
1173 | * The visit function will get start and end parameters that cover the overlap | |
1174 | * between the current vma and the original range. Any unmapped regions in the | |
1175 | * original range will result in this function returning -ENOMEM while still | |
1176 | * calling the visit function on all of the existing vmas in the range. | |
1177 | * Must be called with the mmap_lock held for reading or writing. | |
1178 | */ | |
1179 | static | |
1180 | int madvise_walk_vmas(struct mm_struct *mm, unsigned long start, | |
1181 | unsigned long end, unsigned long arg, | |
1182 | int (*visit)(struct vm_area_struct *vma, | |
1183 | struct vm_area_struct **prev, unsigned long start, | |
1184 | unsigned long end, unsigned long arg)) | |
1185 | { | |
1186 | struct vm_area_struct *vma; | |
1187 | struct vm_area_struct *prev; | |
1188 | unsigned long tmp; | |
1189 | int unmapped_error = 0; | |
1190 | ||
1191 | /* | |
1192 | * If the interval [start,end) covers some unmapped address | |
1193 | * ranges, just ignore them, but return -ENOMEM at the end. | |
1194 | * - different from the way of handling in mlock etc. | |
1195 | */ | |
1196 | vma = find_vma_prev(mm, start, &prev); | |
1197 | if (vma && start > vma->vm_start) | |
1198 | prev = vma; | |
1199 | ||
1200 | for (;;) { | |
1201 | int error; | |
1202 | ||
1203 | /* Still start < end. */ | |
1204 | if (!vma) | |
1205 | return -ENOMEM; | |
1206 | ||
1207 | /* Here start < (end|vma->vm_end). */ | |
1208 | if (start < vma->vm_start) { | |
1209 | unmapped_error = -ENOMEM; | |
1210 | start = vma->vm_start; | |
1211 | if (start >= end) | |
1212 | break; | |
1213 | } | |
1214 | ||
1215 | /* Here vma->vm_start <= start < (end|vma->vm_end) */ | |
1216 | tmp = vma->vm_end; | |
1217 | if (end < tmp) | |
1218 | tmp = end; | |
1219 | ||
1220 | /* Here vma->vm_start <= start < tmp <= (end|vma->vm_end). */ | |
1221 | error = visit(vma, &prev, start, tmp, arg); | |
1222 | if (error) | |
1223 | return error; | |
1224 | start = tmp; | |
1225 | if (prev && start < prev->vm_end) | |
1226 | start = prev->vm_end; | |
1227 | if (start >= end) | |
1228 | break; | |
1229 | if (prev) | |
1230 | vma = prev->vm_next; | |
1231 | else /* madvise_remove dropped mmap_lock */ | |
1232 | vma = find_vma(mm, start); | |
1233 | } | |
1234 | ||
1235 | return unmapped_error; | |
1236 | } | |
1237 | ||
9a10064f CC |
1238 | #ifdef CONFIG_ANON_VMA_NAME |
1239 | static int madvise_vma_anon_name(struct vm_area_struct *vma, | |
1240 | struct vm_area_struct **prev, | |
1241 | unsigned long start, unsigned long end, | |
5c26f6ac | 1242 | unsigned long anon_name) |
9a10064f CC |
1243 | { |
1244 | int error; | |
1245 | ||
1246 | /* Only anonymous mappings can be named */ | |
1247 | if (vma->vm_file) | |
1248 | return -EBADF; | |
1249 | ||
1250 | error = madvise_update_vma(vma, prev, start, end, vma->vm_flags, | |
5c26f6ac | 1251 | (struct anon_vma_name *)anon_name); |
9a10064f CC |
1252 | |
1253 | /* | |
1254 | * madvise() returns EAGAIN if kernel resources, such as | |
1255 | * slab, are temporarily unavailable. | |
1256 | */ | |
1257 | if (error == -ENOMEM) | |
1258 | error = -EAGAIN; | |
1259 | return error; | |
1260 | } | |
1261 | ||
1262 | int madvise_set_anon_name(struct mm_struct *mm, unsigned long start, | |
5c26f6ac | 1263 | unsigned long len_in, struct anon_vma_name *anon_name) |
9a10064f CC |
1264 | { |
1265 | unsigned long end; | |
1266 | unsigned long len; | |
1267 | ||
1268 | if (start & ~PAGE_MASK) | |
1269 | return -EINVAL; | |
1270 | len = (len_in + ~PAGE_MASK) & PAGE_MASK; | |
1271 | ||
1272 | /* Check to see whether len was rounded up from small -ve to zero */ | |
1273 | if (len_in && !len) | |
1274 | return -EINVAL; | |
1275 | ||
1276 | end = start + len; | |
1277 | if (end < start) | |
1278 | return -EINVAL; | |
1279 | ||
1280 | if (end == start) | |
1281 | return 0; | |
1282 | ||
5c26f6ac | 1283 | return madvise_walk_vmas(mm, start, end, (unsigned long)anon_name, |
9a10064f CC |
1284 | madvise_vma_anon_name); |
1285 | } | |
1286 | #endif /* CONFIG_ANON_VMA_NAME */ | |
1da177e4 LT |
1287 | /* |
1288 | * The madvise(2) system call. | |
1289 | * | |
1290 | * Applications can use madvise() to advise the kernel how it should | |
1291 | * handle paging I/O in this VM area. The idea is to help the kernel | |
1292 | * use appropriate read-ahead and caching techniques. The information | |
1293 | * provided is advisory only, and can be safely disregarded by the | |
1294 | * kernel without affecting the correct operation of the application. | |
1295 | * | |
1296 | * behavior values: | |
1297 | * MADV_NORMAL - the default behavior is to read clusters. This | |
1298 | * results in some read-ahead and read-behind. | |
1299 | * MADV_RANDOM - the system should read the minimum amount of data | |
1300 | * on any access, since it is unlikely that the appli- | |
1301 | * cation will need more than what it asks for. | |
1302 | * MADV_SEQUENTIAL - pages in the given range will probably be accessed | |
1303 | * once, so they can be aggressively read ahead, and | |
1304 | * can be freed soon after they are accessed. | |
1305 | * MADV_WILLNEED - the application is notifying the system to read | |
1306 | * some pages ahead. | |
1307 | * MADV_DONTNEED - the application is finished with the given range, | |
1308 | * so the kernel can free resources associated with it. | |
d7206a70 NH |
1309 | * MADV_FREE - the application marks pages in the given range as lazy free, |
1310 | * where actual purges are postponed until memory pressure happens. | |
f6b3ec23 BP |
1311 | * MADV_REMOVE - the application wants to free up the given range of |
1312 | * pages and associated backing store. | |
3866ea90 HD |
1313 | * MADV_DONTFORK - omit this area from child's address space when forking: |
1314 | * typically, to avoid COWing pages pinned by get_user_pages(). | |
1315 | * MADV_DOFORK - cancel MADV_DONTFORK: no longer omit this area when forking. | |
c02c3009 YS |
1316 | * MADV_WIPEONFORK - present the child process with zero-filled memory in this |
1317 | * range after a fork. | |
1318 | * MADV_KEEPONFORK - undo the effect of MADV_WIPEONFORK | |
d7206a70 NH |
1319 | * MADV_HWPOISON - trigger memory error handler as if the given memory range |
1320 | * were corrupted by unrecoverable hardware memory failure. | |
1321 | * MADV_SOFT_OFFLINE - try to soft-offline the given range of memory. | |
f8af4da3 HD |
1322 | * MADV_MERGEABLE - the application recommends that KSM try to merge pages in |
1323 | * this area with pages of identical content from other such areas. | |
1324 | * MADV_UNMERGEABLE- cancel MADV_MERGEABLE: no longer merge pages with others. | |
d7206a70 NH |
1325 | * MADV_HUGEPAGE - the application wants to back the given range by transparent |
1326 | * huge pages in the future. Existing pages might be coalesced and | |
1327 | * new pages might be allocated as THP. | |
1328 | * MADV_NOHUGEPAGE - mark the given range as not worth being backed by | |
1329 | * transparent huge pages so the existing pages will not be | |
1330 | * coalesced into THP and new pages will not be allocated as THP. | |
1331 | * MADV_DONTDUMP - the application wants to prevent pages in the given range | |
1332 | * from being included in its core dump. | |
1333 | * MADV_DODUMP - cancel MADV_DONTDUMP: no longer exclude from core dump. | |
ecb8ac8b MK |
1334 | * MADV_COLD - the application is not expected to use this memory soon, |
1335 | * deactivate pages in this range so that they can be reclaimed | |
f0953a1b | 1336 | * easily if memory pressure happens. |
ecb8ac8b MK |
1337 | * MADV_PAGEOUT - the application is not expected to use this memory soon, |
1338 | * page out the pages in this range immediately. | |
4ca9b385 DH |
1339 | * MADV_POPULATE_READ - populate (prefault) page tables readable by |
1340 | * triggering read faults if required | |
1341 | * MADV_POPULATE_WRITE - populate (prefault) page tables writable by | |
1342 | * triggering write faults if required | |
1da177e4 LT |
1343 | * |
1344 | * return values: | |
1345 | * zero - success | |
1346 | * -EINVAL - start + len < 0, start is not page-aligned, | |
1347 | * "behavior" is not a valid value, or application | |
c02c3009 YS |
1348 | * is attempting to release locked or shared pages, |
1349 | * or the specified address range includes file, Huge TLB, | |
1350 | * MAP_SHARED or VMPFNMAP range. | |
1da177e4 LT |
1351 | * -ENOMEM - addresses in the specified range are not currently |
1352 | * mapped, or are outside the AS of the process. | |
1353 | * -EIO - an I/O error occurred while paging in data. | |
1354 | * -EBADF - map exists, but area maps something that isn't a file. | |
1355 | * -EAGAIN - a kernel resource was temporarily unavailable. | |
1356 | */ | |
0726b01e | 1357 | int do_madvise(struct mm_struct *mm, unsigned long start, size_t len_in, int behavior) |
1da177e4 | 1358 | { |
ac1e9acc CC |
1359 | unsigned long end; |
1360 | int error; | |
f7977793 | 1361 | int write; |
1da177e4 | 1362 | size_t len; |
1998cc04 | 1363 | struct blk_plug plug; |
1da177e4 | 1364 | |
057d3389 AK |
1365 | start = untagged_addr(start); |
1366 | ||
75927af8 | 1367 | if (!madvise_behavior_valid(behavior)) |
ac1e9acc | 1368 | return -EINVAL; |
75927af8 | 1369 | |
df6c6500 | 1370 | if (!PAGE_ALIGNED(start)) |
ac1e9acc | 1371 | return -EINVAL; |
df6c6500 | 1372 | len = PAGE_ALIGN(len_in); |
1da177e4 LT |
1373 | |
1374 | /* Check to see whether len was rounded up from small -ve to zero */ | |
1375 | if (len_in && !len) | |
ac1e9acc | 1376 | return -EINVAL; |
1da177e4 LT |
1377 | |
1378 | end = start + len; | |
1379 | if (end < start) | |
ac1e9acc | 1380 | return -EINVAL; |
1da177e4 | 1381 | |
1da177e4 | 1382 | if (end == start) |
ac1e9acc | 1383 | return 0; |
84d96d89 | 1384 | |
5e451be7 AK |
1385 | #ifdef CONFIG_MEMORY_FAILURE |
1386 | if (behavior == MADV_HWPOISON || behavior == MADV_SOFT_OFFLINE) | |
1387 | return madvise_inject_error(behavior, start, start + len_in); | |
1388 | #endif | |
1389 | ||
84d96d89 | 1390 | write = madvise_need_mmap_write(behavior); |
dc0ef0df | 1391 | if (write) { |
0726b01e | 1392 | if (mmap_write_lock_killable(mm)) |
dc0ef0df MH |
1393 | return -EINTR; |
1394 | } else { | |
0726b01e | 1395 | mmap_read_lock(mm); |
dc0ef0df | 1396 | } |
1da177e4 | 1397 | |
1998cc04 | 1398 | blk_start_plug(&plug); |
ac1e9acc CC |
1399 | error = madvise_walk_vmas(mm, start, end, behavior, |
1400 | madvise_vma_behavior); | |
84d96d89 | 1401 | blk_finish_plug(&plug); |
f7977793 | 1402 | if (write) |
0726b01e | 1403 | mmap_write_unlock(mm); |
0a27a14a | 1404 | else |
0726b01e | 1405 | mmap_read_unlock(mm); |
0a27a14a | 1406 | |
1da177e4 LT |
1407 | return error; |
1408 | } | |
db08ca25 JA |
1409 | |
1410 | SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior) | |
1411 | { | |
0726b01e | 1412 | return do_madvise(current->mm, start, len_in, behavior); |
db08ca25 | 1413 | } |
ecb8ac8b MK |
1414 | |
1415 | SYSCALL_DEFINE5(process_madvise, int, pidfd, const struct iovec __user *, vec, | |
1416 | size_t, vlen, int, behavior, unsigned int, flags) | |
1417 | { | |
1418 | ssize_t ret; | |
1419 | struct iovec iovstack[UIO_FASTIOV], iovec; | |
1420 | struct iovec *iov = iovstack; | |
1421 | struct iov_iter iter; | |
ecb8ac8b MK |
1422 | struct task_struct *task; |
1423 | struct mm_struct *mm; | |
1424 | size_t total_len; | |
1425 | unsigned int f_flags; | |
1426 | ||
1427 | if (flags != 0) { | |
1428 | ret = -EINVAL; | |
1429 | goto out; | |
1430 | } | |
1431 | ||
1432 | ret = import_iovec(READ, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter); | |
1433 | if (ret < 0) | |
1434 | goto out; | |
1435 | ||
ee9955d6 CB |
1436 | task = pidfd_get_task(pidfd, &f_flags); |
1437 | if (IS_ERR(task)) { | |
1438 | ret = PTR_ERR(task); | |
ecb8ac8b MK |
1439 | goto free_iov; |
1440 | } | |
1441 | ||
a68a0262 | 1442 | if (!process_madvise_behavior_valid(behavior)) { |
ecb8ac8b MK |
1443 | ret = -EINVAL; |
1444 | goto release_task; | |
1445 | } | |
1446 | ||
96cfe2c0 SB |
1447 | /* Require PTRACE_MODE_READ to avoid leaking ASLR metadata. */ |
1448 | mm = mm_access(task, PTRACE_MODE_READ_FSCREDS); | |
ecb8ac8b MK |
1449 | if (IS_ERR_OR_NULL(mm)) { |
1450 | ret = IS_ERR(mm) ? PTR_ERR(mm) : -ESRCH; | |
1451 | goto release_task; | |
1452 | } | |
1453 | ||
96cfe2c0 SB |
1454 | /* |
1455 | * Require CAP_SYS_NICE for influencing process performance. Note that | |
1456 | * only non-destructive hints are currently supported. | |
1457 | */ | |
1458 | if (!capable(CAP_SYS_NICE)) { | |
1459 | ret = -EPERM; | |
1460 | goto release_mm; | |
1461 | } | |
1462 | ||
ecb8ac8b MK |
1463 | total_len = iov_iter_count(&iter); |
1464 | ||
1465 | while (iov_iter_count(&iter)) { | |
1466 | iovec = iov_iter_iovec(&iter); | |
1467 | ret = do_madvise(mm, (unsigned long)iovec.iov_base, | |
1468 | iovec.iov_len, behavior); | |
e6b0a7b3 | 1469 | if (ret < 0) |
ecb8ac8b MK |
1470 | break; |
1471 | iov_iter_advance(&iter, iovec.iov_len); | |
1472 | } | |
1473 | ||
5bd009c7 | 1474 | ret = (total_len - iov_iter_count(&iter)) ? : ret; |
ecb8ac8b | 1475 | |
96cfe2c0 | 1476 | release_mm: |
ecb8ac8b | 1477 | mmput(mm); |
ecb8ac8b MK |
1478 | release_task: |
1479 | put_task_struct(task); | |
ecb8ac8b MK |
1480 | free_iov: |
1481 | kfree(iov); | |
1482 | out: | |
1483 | return ret; | |
1484 | } |