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 | 37 | #include "internal.h" |
014bb1de | 38 | #include "swap.h" |
23519073 | 39 | |
d616d512 MK |
40 | struct madvise_walk_private { |
41 | struct mmu_gather *tlb; | |
42 | bool pageout; | |
43 | }; | |
44 | ||
0a27a14a NP |
45 | /* |
46 | * Any behaviour which results in changes to the vma->vm_flags needs to | |
c1e8d7c6 | 47 | * take mmap_lock for writing. Others, which simply traverse vmas, need |
0a27a14a NP |
48 | * to only take it for reading. |
49 | */ | |
50 | static int madvise_need_mmap_write(int behavior) | |
51 | { | |
52 | switch (behavior) { | |
53 | case MADV_REMOVE: | |
54 | case MADV_WILLNEED: | |
55 | case MADV_DONTNEED: | |
9457056a | 56 | case MADV_DONTNEED_LOCKED: |
9c276cc6 | 57 | case MADV_COLD: |
1a4e58cc | 58 | case MADV_PAGEOUT: |
854e9ed0 | 59 | case MADV_FREE: |
4ca9b385 DH |
60 | case MADV_POPULATE_READ: |
61 | case MADV_POPULATE_WRITE: | |
7d8faaf1 | 62 | case MADV_COLLAPSE: |
0a27a14a NP |
63 | return 0; |
64 | default: | |
65 | /* be safe, default to 1. list exceptions explicitly */ | |
66 | return 1; | |
67 | } | |
68 | } | |
69 | ||
9a10064f | 70 | #ifdef CONFIG_ANON_VMA_NAME |
5c26f6ac | 71 | struct anon_vma_name *anon_vma_name_alloc(const char *name) |
78db3412 SB |
72 | { |
73 | struct anon_vma_name *anon_name; | |
74 | size_t count; | |
75 | ||
76 | /* Add 1 for NUL terminator at the end of the anon_name->name */ | |
77 | count = strlen(name) + 1; | |
78 | anon_name = kmalloc(struct_size(anon_name, name, count), GFP_KERNEL); | |
79 | if (anon_name) { | |
80 | kref_init(&anon_name->kref); | |
81 | memcpy(anon_name->name, name, count); | |
82 | } | |
83 | ||
84 | return anon_name; | |
85 | } | |
86 | ||
5c26f6ac | 87 | void anon_vma_name_free(struct kref *kref) |
78db3412 SB |
88 | { |
89 | struct anon_vma_name *anon_name = | |
90 | container_of(kref, struct anon_vma_name, kref); | |
91 | kfree(anon_name); | |
92 | } | |
93 | ||
5c26f6ac | 94 | struct anon_vma_name *anon_vma_name(struct vm_area_struct *vma) |
9a10064f | 95 | { |
9a10064f CC |
96 | mmap_assert_locked(vma->vm_mm); |
97 | ||
5c26f6ac | 98 | return vma->anon_name; |
9a10064f CC |
99 | } |
100 | ||
101 | /* mmap_lock should be write-locked */ | |
5c26f6ac SB |
102 | static int replace_anon_vma_name(struct vm_area_struct *vma, |
103 | struct anon_vma_name *anon_name) | |
9a10064f | 104 | { |
5c26f6ac | 105 | struct anon_vma_name *orig_name = anon_vma_name(vma); |
78db3412 | 106 | |
5c26f6ac SB |
107 | if (!anon_name) { |
108 | vma->anon_name = NULL; | |
109 | anon_vma_name_put(orig_name); | |
9a10064f CC |
110 | return 0; |
111 | } | |
112 | ||
5c26f6ac SB |
113 | if (anon_vma_name_eq(orig_name, anon_name)) |
114 | return 0; | |
9a10064f | 115 | |
96403e11 | 116 | vma->anon_name = anon_vma_name_reuse(anon_name); |
5c26f6ac | 117 | anon_vma_name_put(orig_name); |
9a10064f CC |
118 | |
119 | return 0; | |
120 | } | |
121 | #else /* CONFIG_ANON_VMA_NAME */ | |
5c26f6ac SB |
122 | static int replace_anon_vma_name(struct vm_area_struct *vma, |
123 | struct anon_vma_name *anon_name) | |
9a10064f | 124 | { |
5c26f6ac | 125 | if (anon_name) |
9a10064f CC |
126 | return -EINVAL; |
127 | ||
128 | return 0; | |
129 | } | |
130 | #endif /* CONFIG_ANON_VMA_NAME */ | |
1da177e4 | 131 | /* |
ac1e9acc CC |
132 | * Update the vm_flags on region of a vma, splitting it or merging it as |
133 | * necessary. Must be called with mmap_sem held for writing; | |
942341dc SB |
134 | * Caller should ensure anon_name stability by raising its refcount even when |
135 | * anon_name belongs to a valid vma because this function might free that vma. | |
1da177e4 | 136 | */ |
ac1e9acc CC |
137 | static int madvise_update_vma(struct vm_area_struct *vma, |
138 | struct vm_area_struct **prev, unsigned long start, | |
9a10064f | 139 | unsigned long end, unsigned long new_flags, |
5c26f6ac | 140 | struct anon_vma_name *anon_name) |
1da177e4 | 141 | { |
ec9bed9d | 142 | struct mm_struct *mm = vma->vm_mm; |
ac1e9acc | 143 | int error; |
05b74384 | 144 | pgoff_t pgoff; |
e798c6e8 | 145 | |
5c26f6ac | 146 | if (new_flags == vma->vm_flags && anon_vma_name_eq(anon_vma_name(vma), anon_name)) { |
05b74384 | 147 | *prev = vma; |
ac1e9acc | 148 | return 0; |
05b74384 PM |
149 | } |
150 | ||
151 | pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); | |
152 | *prev = vma_merge(mm, *prev, start, end, new_flags, vma->anon_vma, | |
19a809af | 153 | vma->vm_file, pgoff, vma_policy(vma), |
5c26f6ac | 154 | vma->vm_userfaultfd_ctx, anon_name); |
05b74384 PM |
155 | if (*prev) { |
156 | vma = *prev; | |
157 | goto success; | |
158 | } | |
159 | ||
160 | *prev = vma; | |
1da177e4 LT |
161 | |
162 | if (start != vma->vm_start) { | |
ac1e9acc CC |
163 | if (unlikely(mm->map_count >= sysctl_max_map_count)) |
164 | return -ENOMEM; | |
def5efe0 | 165 | error = __split_vma(mm, vma, start, 1); |
f3bc0dba | 166 | if (error) |
ac1e9acc | 167 | return error; |
1da177e4 LT |
168 | } |
169 | ||
170 | if (end != vma->vm_end) { | |
ac1e9acc CC |
171 | if (unlikely(mm->map_count >= sysctl_max_map_count)) |
172 | return -ENOMEM; | |
def5efe0 | 173 | error = __split_vma(mm, vma, end, 0); |
f3bc0dba | 174 | if (error) |
ac1e9acc | 175 | return error; |
1da177e4 LT |
176 | } |
177 | ||
836d5ffd | 178 | success: |
1da177e4 | 179 | /* |
c1e8d7c6 | 180 | * vm_flags is protected by the mmap_lock held in write mode. |
1da177e4 | 181 | */ |
e798c6e8 | 182 | vma->vm_flags = new_flags; |
d09e8ca6 | 183 | if (!vma->vm_file || vma_is_anon_shmem(vma)) { |
5c26f6ac | 184 | error = replace_anon_vma_name(vma, anon_name); |
9a10064f CC |
185 | if (error) |
186 | return error; | |
187 | } | |
f3bc0dba | 188 | |
ac1e9acc | 189 | return 0; |
1da177e4 LT |
190 | } |
191 | ||
1998cc04 SL |
192 | #ifdef CONFIG_SWAP |
193 | static int swapin_walk_pmd_entry(pmd_t *pmd, unsigned long start, | |
194 | unsigned long end, struct mm_walk *walk) | |
195 | { | |
1998cc04 SL |
196 | struct vm_area_struct *vma = walk->private; |
197 | unsigned long index; | |
5169b844 | 198 | struct swap_iocb *splug = NULL; |
1998cc04 SL |
199 | |
200 | if (pmd_none_or_trans_huge_or_clear_bad(pmd)) | |
201 | return 0; | |
202 | ||
203 | for (index = start; index != end; index += PAGE_SIZE) { | |
204 | pte_t pte; | |
205 | swp_entry_t entry; | |
206 | struct page *page; | |
207 | spinlock_t *ptl; | |
f7cc67ae | 208 | pte_t *ptep; |
1998cc04 | 209 | |
f7cc67ae ML |
210 | ptep = pte_offset_map_lock(vma->vm_mm, pmd, index, &ptl); |
211 | pte = *ptep; | |
212 | pte_unmap_unlock(ptep, ptl); | |
1998cc04 | 213 | |
f7cc67ae | 214 | if (!is_swap_pte(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, | |
5169b844 | 221 | vma, index, false, &splug); |
1998cc04 | 222 | if (page) |
09cbfeaf | 223 | put_page(page); |
1998cc04 | 224 | } |
5169b844 | 225 | swap_read_unplug(splug); |
de2e5171 | 226 | cond_resched(); |
1998cc04 SL |
227 | |
228 | return 0; | |
229 | } | |
230 | ||
7b86ac33 CH |
231 | static const struct mm_walk_ops swapin_walk_ops = { |
232 | .pmd_entry = swapin_walk_pmd_entry, | |
233 | }; | |
1998cc04 SL |
234 | |
235 | static void force_shm_swapin_readahead(struct vm_area_struct *vma, | |
236 | unsigned long start, unsigned long end, | |
237 | struct address_space *mapping) | |
238 | { | |
e6e88712 | 239 | XA_STATE(xas, &mapping->i_pages, linear_page_index(vma, start)); |
66383800 | 240 | pgoff_t end_index = linear_page_index(vma, end + PAGE_SIZE - 1); |
1998cc04 | 241 | struct page *page; |
5169b844 | 242 | struct swap_iocb *splug = NULL; |
1998cc04 | 243 | |
e6e88712 MWO |
244 | rcu_read_lock(); |
245 | xas_for_each(&xas, page, end_index) { | |
246 | swp_entry_t swap; | |
1998cc04 | 247 | |
e6e88712 | 248 | if (!xa_is_value(page)) |
1998cc04 | 249 | continue; |
ba6851b4 ML |
250 | swap = radix_to_swp_entry(page); |
251 | /* There might be swapin error entries in shmem mapping. */ | |
252 | if (non_swap_entry(swap)) | |
253 | continue; | |
e6e88712 MWO |
254 | xas_pause(&xas); |
255 | rcu_read_unlock(); | |
256 | ||
1998cc04 | 257 | page = read_swap_cache_async(swap, GFP_HIGHUSER_MOVABLE, |
5169b844 | 258 | NULL, 0, false, &splug); |
1998cc04 | 259 | if (page) |
09cbfeaf | 260 | put_page(page); |
e6e88712 MWO |
261 | |
262 | rcu_read_lock(); | |
1998cc04 | 263 | } |
e6e88712 | 264 | rcu_read_unlock(); |
5169b844 | 265 | swap_read_unplug(splug); |
1998cc04 SL |
266 | |
267 | lru_add_drain(); /* Push any new pages onto the LRU now */ | |
268 | } | |
269 | #endif /* CONFIG_SWAP */ | |
270 | ||
1da177e4 LT |
271 | /* |
272 | * Schedule all required I/O operations. Do not wait for completion. | |
273 | */ | |
ec9bed9d VC |
274 | static long madvise_willneed(struct vm_area_struct *vma, |
275 | struct vm_area_struct **prev, | |
1da177e4 LT |
276 | unsigned long start, unsigned long end) |
277 | { | |
0726b01e | 278 | struct mm_struct *mm = vma->vm_mm; |
1da177e4 | 279 | struct file *file = vma->vm_file; |
692fe624 | 280 | loff_t offset; |
1da177e4 | 281 | |
6ea8d958 | 282 | *prev = vma; |
1998cc04 | 283 | #ifdef CONFIG_SWAP |
97b713ba | 284 | if (!file) { |
7b86ac33 CH |
285 | walk_page_range(vma->vm_mm, start, end, &swapin_walk_ops, vma); |
286 | lru_add_drain(); /* Push any new pages onto the LRU now */ | |
1998cc04 SL |
287 | return 0; |
288 | } | |
1998cc04 | 289 | |
97b713ba | 290 | if (shmem_mapping(file->f_mapping)) { |
97b713ba CH |
291 | force_shm_swapin_readahead(vma, start, end, |
292 | file->f_mapping); | |
293 | return 0; | |
294 | } | |
295 | #else | |
1bef4003 S |
296 | if (!file) |
297 | return -EBADF; | |
97b713ba | 298 | #endif |
1bef4003 | 299 | |
e748dcd0 | 300 | if (IS_DAX(file_inode(file))) { |
fe77ba6f CO |
301 | /* no bad return value, but ignore advice */ |
302 | return 0; | |
303 | } | |
304 | ||
692fe624 JK |
305 | /* |
306 | * Filesystem's fadvise may need to take various locks. We need to | |
307 | * explicitly grab a reference because the vma (and hence the | |
308 | * vma's reference to the file) can go away as soon as we drop | |
c1e8d7c6 | 309 | * mmap_lock. |
692fe624 | 310 | */ |
c1e8d7c6 | 311 | *prev = NULL; /* tell sys_madvise we drop mmap_lock */ |
692fe624 | 312 | get_file(file); |
692fe624 JK |
313 | offset = (loff_t)(start - vma->vm_start) |
314 | + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); | |
0726b01e | 315 | mmap_read_unlock(mm); |
692fe624 JK |
316 | vfs_fadvise(file, offset, end - start, POSIX_FADV_WILLNEED); |
317 | fput(file); | |
0726b01e | 318 | mmap_read_lock(mm); |
1da177e4 LT |
319 | return 0; |
320 | } | |
321 | ||
fd3b1bc3 PK |
322 | static inline bool can_do_file_pageout(struct vm_area_struct *vma) |
323 | { | |
324 | if (!vma->vm_file) | |
325 | return false; | |
326 | /* | |
327 | * paging out pagecache only for non-anonymous mappings that correspond | |
328 | * to the files the calling process could (if tried) open for writing; | |
329 | * otherwise we'd be including shared non-exclusive mappings, which | |
330 | * opens a side channel. | |
331 | */ | |
332 | return inode_owner_or_capable(&init_user_ns, | |
333 | file_inode(vma->vm_file)) || | |
334 | file_permission(vma->vm_file, MAY_WRITE) == 0; | |
335 | } | |
336 | ||
d616d512 MK |
337 | static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, |
338 | unsigned long addr, unsigned long end, | |
339 | struct mm_walk *walk) | |
9c276cc6 | 340 | { |
d616d512 MK |
341 | struct madvise_walk_private *private = walk->private; |
342 | struct mmu_gather *tlb = private->tlb; | |
343 | bool pageout = private->pageout; | |
9c276cc6 MK |
344 | struct mm_struct *mm = tlb->mm; |
345 | struct vm_area_struct *vma = walk->vma; | |
346 | pte_t *orig_pte, *pte, ptent; | |
347 | spinlock_t *ptl; | |
d616d512 MK |
348 | struct page *page = NULL; |
349 | LIST_HEAD(page_list); | |
fd3b1bc3 | 350 | bool pageout_anon_only_filter; |
d616d512 MK |
351 | |
352 | if (fatal_signal_pending(current)) | |
353 | return -EINTR; | |
9c276cc6 | 354 | |
fd3b1bc3 PK |
355 | pageout_anon_only_filter = pageout && !vma_is_anonymous(vma) && |
356 | !can_do_file_pageout(vma); | |
357 | ||
9c276cc6 MK |
358 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
359 | if (pmd_trans_huge(*pmd)) { | |
360 | pmd_t orig_pmd; | |
361 | unsigned long next = pmd_addr_end(addr, end); | |
362 | ||
363 | tlb_change_page_size(tlb, HPAGE_PMD_SIZE); | |
364 | ptl = pmd_trans_huge_lock(pmd, vma); | |
365 | if (!ptl) | |
366 | return 0; | |
367 | ||
368 | orig_pmd = *pmd; | |
369 | if (is_huge_zero_pmd(orig_pmd)) | |
370 | goto huge_unlock; | |
371 | ||
372 | if (unlikely(!pmd_present(orig_pmd))) { | |
373 | VM_BUG_ON(thp_migration_supported() && | |
374 | !is_pmd_migration_entry(orig_pmd)); | |
375 | goto huge_unlock; | |
376 | } | |
377 | ||
378 | page = pmd_page(orig_pmd); | |
12e967fd MH |
379 | |
380 | /* Do not interfere with other mappings of this page */ | |
381 | if (page_mapcount(page) != 1) | |
382 | goto huge_unlock; | |
383 | ||
fd3b1bc3 PK |
384 | if (pageout_anon_only_filter && !PageAnon(page)) |
385 | goto huge_unlock; | |
386 | ||
9c276cc6 MK |
387 | if (next - addr != HPAGE_PMD_SIZE) { |
388 | int err; | |
389 | ||
9c276cc6 MK |
390 | get_page(page); |
391 | spin_unlock(ptl); | |
392 | lock_page(page); | |
393 | err = split_huge_page(page); | |
394 | unlock_page(page); | |
395 | put_page(page); | |
396 | if (!err) | |
397 | goto regular_page; | |
398 | return 0; | |
399 | } | |
400 | ||
401 | if (pmd_young(orig_pmd)) { | |
402 | pmdp_invalidate(vma, addr, pmd); | |
403 | orig_pmd = pmd_mkold(orig_pmd); | |
404 | ||
405 | set_pmd_at(mm, addr, pmd, orig_pmd); | |
406 | tlb_remove_pmd_tlb_entry(tlb, pmd, addr); | |
407 | } | |
408 | ||
d616d512 | 409 | ClearPageReferenced(page); |
9c276cc6 | 410 | test_and_clear_page_young(page); |
d616d512 | 411 | if (pageout) { |
82072962 | 412 | if (!isolate_lru_page(page)) { |
413 | if (PageUnevictable(page)) | |
414 | putback_lru_page(page); | |
415 | else | |
416 | list_add(&page->lru, &page_list); | |
417 | } | |
d616d512 MK |
418 | } else |
419 | deactivate_page(page); | |
9c276cc6 MK |
420 | huge_unlock: |
421 | spin_unlock(ptl); | |
d616d512 MK |
422 | if (pageout) |
423 | reclaim_pages(&page_list); | |
9c276cc6 MK |
424 | return 0; |
425 | } | |
426 | ||
ce268425 | 427 | regular_page: |
9c276cc6 MK |
428 | if (pmd_trans_unstable(pmd)) |
429 | return 0; | |
9c276cc6 MK |
430 | #endif |
431 | tlb_change_page_size(tlb, PAGE_SIZE); | |
432 | orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
433 | flush_tlb_batched_pending(mm); | |
434 | arch_enter_lazy_mmu_mode(); | |
435 | for (; addr < end; pte++, addr += PAGE_SIZE) { | |
436 | ptent = *pte; | |
437 | ||
438 | if (pte_none(ptent)) | |
439 | continue; | |
440 | ||
441 | if (!pte_present(ptent)) | |
442 | continue; | |
443 | ||
444 | page = vm_normal_page(vma, addr, ptent); | |
3218f871 | 445 | if (!page || is_zone_device_page(page)) |
9c276cc6 MK |
446 | continue; |
447 | ||
448 | /* | |
449 | * Creating a THP page is expensive so split it only if we | |
450 | * are sure it's worth. Split it if we are only owner. | |
451 | */ | |
452 | if (PageTransCompound(page)) { | |
453 | if (page_mapcount(page) != 1) | |
454 | break; | |
fd3b1bc3 PK |
455 | if (pageout_anon_only_filter && !PageAnon(page)) |
456 | break; | |
9c276cc6 MK |
457 | get_page(page); |
458 | if (!trylock_page(page)) { | |
459 | put_page(page); | |
460 | break; | |
461 | } | |
462 | pte_unmap_unlock(orig_pte, ptl); | |
463 | if (split_huge_page(page)) { | |
464 | unlock_page(page); | |
465 | put_page(page); | |
f3b9e8cc | 466 | orig_pte = pte_offset_map_lock(mm, pmd, addr, &ptl); |
9c276cc6 MK |
467 | break; |
468 | } | |
469 | unlock_page(page); | |
470 | put_page(page); | |
f3b9e8cc | 471 | orig_pte = pte = pte_offset_map_lock(mm, pmd, addr, &ptl); |
9c276cc6 MK |
472 | pte--; |
473 | addr -= PAGE_SIZE; | |
474 | continue; | |
475 | } | |
476 | ||
58d426a7 MK |
477 | /* |
478 | * Do not interfere with other mappings of this page and | |
479 | * non-LRU page. | |
480 | */ | |
481 | if (!PageLRU(page) || page_mapcount(page) != 1) | |
12e967fd MH |
482 | continue; |
483 | ||
fd3b1bc3 PK |
484 | if (pageout_anon_only_filter && !PageAnon(page)) |
485 | continue; | |
486 | ||
9c276cc6 MK |
487 | VM_BUG_ON_PAGE(PageTransCompound(page), page); |
488 | ||
489 | if (pte_young(ptent)) { | |
490 | ptent = ptep_get_and_clear_full(mm, addr, pte, | |
491 | tlb->fullmm); | |
492 | ptent = pte_mkold(ptent); | |
493 | set_pte_at(mm, addr, pte, ptent); | |
494 | tlb_remove_tlb_entry(tlb, pte, addr); | |
495 | } | |
496 | ||
497 | /* | |
498 | * We are deactivating a page for accelerating reclaiming. | |
499 | * VM couldn't reclaim the page unless we clear PG_young. | |
500 | * As a side effect, it makes confuse idle-page tracking | |
501 | * because they will miss recent referenced history. | |
502 | */ | |
d616d512 | 503 | ClearPageReferenced(page); |
9c276cc6 | 504 | test_and_clear_page_young(page); |
d616d512 | 505 | if (pageout) { |
82072962 | 506 | if (!isolate_lru_page(page)) { |
507 | if (PageUnevictable(page)) | |
508 | putback_lru_page(page); | |
509 | else | |
510 | list_add(&page->lru, &page_list); | |
511 | } | |
d616d512 MK |
512 | } else |
513 | deactivate_page(page); | |
9c276cc6 MK |
514 | } |
515 | ||
516 | arch_leave_lazy_mmu_mode(); | |
517 | pte_unmap_unlock(orig_pte, ptl); | |
d616d512 MK |
518 | if (pageout) |
519 | reclaim_pages(&page_list); | |
9c276cc6 MK |
520 | cond_resched(); |
521 | ||
522 | return 0; | |
523 | } | |
524 | ||
525 | static const struct mm_walk_ops cold_walk_ops = { | |
d616d512 | 526 | .pmd_entry = madvise_cold_or_pageout_pte_range, |
9c276cc6 MK |
527 | }; |
528 | ||
529 | static void madvise_cold_page_range(struct mmu_gather *tlb, | |
530 | struct vm_area_struct *vma, | |
531 | unsigned long addr, unsigned long end) | |
532 | { | |
d616d512 MK |
533 | struct madvise_walk_private walk_private = { |
534 | .pageout = false, | |
535 | .tlb = tlb, | |
536 | }; | |
537 | ||
9c276cc6 | 538 | tlb_start_vma(tlb, vma); |
d616d512 | 539 | walk_page_range(vma->vm_mm, addr, end, &cold_walk_ops, &walk_private); |
9c276cc6 MK |
540 | tlb_end_vma(tlb, vma); |
541 | } | |
542 | ||
a213e5cf HD |
543 | static inline bool can_madv_lru_vma(struct vm_area_struct *vma) |
544 | { | |
9457056a | 545 | return !(vma->vm_flags & (VM_LOCKED|VM_PFNMAP|VM_HUGETLB)); |
a213e5cf HD |
546 | } |
547 | ||
9c276cc6 MK |
548 | static long madvise_cold(struct vm_area_struct *vma, |
549 | struct vm_area_struct **prev, | |
550 | unsigned long start_addr, unsigned long end_addr) | |
551 | { | |
552 | struct mm_struct *mm = vma->vm_mm; | |
553 | struct mmu_gather tlb; | |
554 | ||
555 | *prev = vma; | |
556 | if (!can_madv_lru_vma(vma)) | |
557 | return -EINVAL; | |
558 | ||
559 | lru_add_drain(); | |
a72afd87 | 560 | tlb_gather_mmu(&tlb, mm); |
9c276cc6 | 561 | madvise_cold_page_range(&tlb, vma, start_addr, end_addr); |
ae8eba8b | 562 | tlb_finish_mmu(&tlb); |
9c276cc6 MK |
563 | |
564 | return 0; | |
565 | } | |
566 | ||
1a4e58cc MK |
567 | static void madvise_pageout_page_range(struct mmu_gather *tlb, |
568 | struct vm_area_struct *vma, | |
569 | unsigned long addr, unsigned long end) | |
570 | { | |
d616d512 MK |
571 | struct madvise_walk_private walk_private = { |
572 | .pageout = true, | |
573 | .tlb = tlb, | |
574 | }; | |
575 | ||
1a4e58cc | 576 | tlb_start_vma(tlb, vma); |
d616d512 | 577 | walk_page_range(vma->vm_mm, addr, end, &cold_walk_ops, &walk_private); |
1a4e58cc MK |
578 | tlb_end_vma(tlb, vma); |
579 | } | |
580 | ||
1a4e58cc MK |
581 | static long madvise_pageout(struct vm_area_struct *vma, |
582 | struct vm_area_struct **prev, | |
583 | unsigned long start_addr, unsigned long end_addr) | |
584 | { | |
585 | struct mm_struct *mm = vma->vm_mm; | |
586 | struct mmu_gather tlb; | |
587 | ||
588 | *prev = vma; | |
589 | if (!can_madv_lru_vma(vma)) | |
590 | return -EINVAL; | |
591 | ||
fd3b1bc3 PK |
592 | /* |
593 | * If the VMA belongs to a private file mapping, there can be private | |
594 | * dirty pages which can be paged out if even this process is neither | |
595 | * owner nor write capable of the file. We allow private file mappings | |
596 | * further to pageout dirty anon pages. | |
597 | */ | |
598 | if (!vma_is_anonymous(vma) && (!can_do_file_pageout(vma) && | |
599 | (vma->vm_flags & VM_MAYSHARE))) | |
1a4e58cc MK |
600 | return 0; |
601 | ||
602 | lru_add_drain(); | |
a72afd87 | 603 | tlb_gather_mmu(&tlb, mm); |
1a4e58cc | 604 | madvise_pageout_page_range(&tlb, vma, start_addr, end_addr); |
ae8eba8b | 605 | tlb_finish_mmu(&tlb); |
1a4e58cc MK |
606 | |
607 | return 0; | |
608 | } | |
609 | ||
854e9ed0 MK |
610 | static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr, |
611 | unsigned long end, struct mm_walk *walk) | |
612 | ||
613 | { | |
614 | struct mmu_gather *tlb = walk->private; | |
615 | struct mm_struct *mm = tlb->mm; | |
616 | struct vm_area_struct *vma = walk->vma; | |
617 | spinlock_t *ptl; | |
618 | pte_t *orig_pte, *pte, ptent; | |
98b211d6 | 619 | struct folio *folio; |
854e9ed0 | 620 | struct page *page; |
64b42bc1 | 621 | int nr_swap = 0; |
b8d3c4c3 MK |
622 | unsigned long next; |
623 | ||
624 | next = pmd_addr_end(addr, end); | |
625 | if (pmd_trans_huge(*pmd)) | |
626 | if (madvise_free_huge_pmd(tlb, vma, pmd, addr, next)) | |
627 | goto next; | |
854e9ed0 | 628 | |
854e9ed0 MK |
629 | if (pmd_trans_unstable(pmd)) |
630 | return 0; | |
631 | ||
ed6a7935 | 632 | tlb_change_page_size(tlb, PAGE_SIZE); |
854e9ed0 | 633 | orig_pte = pte = pte_offset_map_lock(mm, pmd, addr, &ptl); |
3ea27719 | 634 | flush_tlb_batched_pending(mm); |
854e9ed0 MK |
635 | arch_enter_lazy_mmu_mode(); |
636 | for (; addr != end; pte++, addr += PAGE_SIZE) { | |
637 | ptent = *pte; | |
638 | ||
64b42bc1 | 639 | if (pte_none(ptent)) |
854e9ed0 | 640 | continue; |
64b42bc1 MK |
641 | /* |
642 | * If the pte has swp_entry, just clear page table to | |
643 | * prevent swap-in which is more expensive rather than | |
644 | * (page allocation + zeroing). | |
645 | */ | |
646 | if (!pte_present(ptent)) { | |
647 | swp_entry_t entry; | |
648 | ||
649 | entry = pte_to_swp_entry(ptent); | |
7b49514f ML |
650 | if (!non_swap_entry(entry)) { |
651 | nr_swap--; | |
652 | free_swap_and_cache(entry); | |
653 | pte_clear_not_present_full(mm, addr, pte, tlb->fullmm); | |
654 | } else if (is_hwpoison_entry(entry) || | |
655 | is_swapin_error_entry(entry)) { | |
656 | pte_clear_not_present_full(mm, addr, pte, tlb->fullmm); | |
657 | } | |
64b42bc1 MK |
658 | continue; |
659 | } | |
854e9ed0 | 660 | |
25b2995a | 661 | page = vm_normal_page(vma, addr, ptent); |
3218f871 | 662 | if (!page || is_zone_device_page(page)) |
854e9ed0 | 663 | continue; |
98b211d6 | 664 | folio = page_folio(page); |
854e9ed0 MK |
665 | |
666 | /* | |
98b211d6 | 667 | * If pmd isn't transhuge but the folio is large and |
854e9ed0 MK |
668 | * is owned by only this process, split it and |
669 | * deactivate all pages. | |
670 | */ | |
98b211d6 MWO |
671 | if (folio_test_large(folio)) { |
672 | if (folio_mapcount(folio) != 1) | |
854e9ed0 | 673 | goto out; |
98b211d6 MWO |
674 | folio_get(folio); |
675 | if (!folio_trylock(folio)) { | |
676 | folio_put(folio); | |
854e9ed0 MK |
677 | goto out; |
678 | } | |
679 | pte_unmap_unlock(orig_pte, ptl); | |
98b211d6 MWO |
680 | if (split_folio(folio)) { |
681 | folio_unlock(folio); | |
682 | folio_put(folio); | |
f3b9e8cc | 683 | orig_pte = pte_offset_map_lock(mm, pmd, addr, &ptl); |
854e9ed0 MK |
684 | goto out; |
685 | } | |
98b211d6 MWO |
686 | folio_unlock(folio); |
687 | folio_put(folio); | |
f3b9e8cc | 688 | orig_pte = pte = pte_offset_map_lock(mm, pmd, addr, &ptl); |
854e9ed0 MK |
689 | pte--; |
690 | addr -= PAGE_SIZE; | |
691 | continue; | |
692 | } | |
693 | ||
98b211d6 MWO |
694 | if (folio_test_swapcache(folio) || folio_test_dirty(folio)) { |
695 | if (!folio_trylock(folio)) | |
854e9ed0 MK |
696 | continue; |
697 | /* | |
98b211d6 MWO |
698 | * If folio is shared with others, we mustn't clear |
699 | * the folio's dirty flag. | |
854e9ed0 | 700 | */ |
98b211d6 MWO |
701 | if (folio_mapcount(folio) != 1) { |
702 | folio_unlock(folio); | |
854e9ed0 MK |
703 | continue; |
704 | } | |
705 | ||
98b211d6 MWO |
706 | if (folio_test_swapcache(folio) && |
707 | !folio_free_swap(folio)) { | |
708 | folio_unlock(folio); | |
854e9ed0 MK |
709 | continue; |
710 | } | |
711 | ||
98b211d6 MWO |
712 | folio_clear_dirty(folio); |
713 | folio_unlock(folio); | |
854e9ed0 MK |
714 | } |
715 | ||
716 | if (pte_young(ptent) || pte_dirty(ptent)) { | |
717 | /* | |
718 | * Some of architecture(ex, PPC) don't update TLB | |
719 | * with set_pte_at and tlb_remove_tlb_entry so for | |
720 | * the portability, remap the pte with old|clean | |
721 | * after pte clearing. | |
722 | */ | |
723 | ptent = ptep_get_and_clear_full(mm, addr, pte, | |
724 | tlb->fullmm); | |
725 | ||
726 | ptent = pte_mkold(ptent); | |
727 | ptent = pte_mkclean(ptent); | |
728 | set_pte_at(mm, addr, pte, ptent); | |
729 | tlb_remove_tlb_entry(tlb, pte, addr); | |
730 | } | |
98b211d6 | 731 | mark_page_lazyfree(&folio->page); |
854e9ed0 MK |
732 | } |
733 | out: | |
64b42bc1 MK |
734 | if (nr_swap) { |
735 | if (current->mm == mm) | |
736 | sync_mm_rss(mm); | |
737 | ||
738 | add_mm_counter(mm, MM_SWAPENTS, nr_swap); | |
739 | } | |
854e9ed0 MK |
740 | arch_leave_lazy_mmu_mode(); |
741 | pte_unmap_unlock(orig_pte, ptl); | |
742 | cond_resched(); | |
b8d3c4c3 | 743 | next: |
854e9ed0 MK |
744 | return 0; |
745 | } | |
746 | ||
7b86ac33 CH |
747 | static const struct mm_walk_ops madvise_free_walk_ops = { |
748 | .pmd_entry = madvise_free_pte_range, | |
749 | }; | |
854e9ed0 MK |
750 | |
751 | static int madvise_free_single_vma(struct vm_area_struct *vma, | |
752 | unsigned long start_addr, unsigned long end_addr) | |
753 | { | |
854e9ed0 | 754 | struct mm_struct *mm = vma->vm_mm; |
ac46d4f3 | 755 | struct mmu_notifier_range range; |
854e9ed0 MK |
756 | struct mmu_gather tlb; |
757 | ||
854e9ed0 MK |
758 | /* MADV_FREE works for only anon vma at the moment */ |
759 | if (!vma_is_anonymous(vma)) | |
760 | return -EINVAL; | |
761 | ||
ac46d4f3 JG |
762 | range.start = max(vma->vm_start, start_addr); |
763 | if (range.start >= vma->vm_end) | |
854e9ed0 | 764 | return -EINVAL; |
ac46d4f3 JG |
765 | range.end = min(vma->vm_end, end_addr); |
766 | if (range.end <= vma->vm_start) | |
854e9ed0 | 767 | return -EINVAL; |
7269f999 | 768 | mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, |
6f4f13e8 | 769 | range.start, range.end); |
854e9ed0 MK |
770 | |
771 | lru_add_drain(); | |
a72afd87 | 772 | tlb_gather_mmu(&tlb, mm); |
854e9ed0 MK |
773 | update_hiwater_rss(mm); |
774 | ||
ac46d4f3 | 775 | mmu_notifier_invalidate_range_start(&range); |
7b86ac33 CH |
776 | tlb_start_vma(&tlb, vma); |
777 | walk_page_range(vma->vm_mm, range.start, range.end, | |
778 | &madvise_free_walk_ops, &tlb); | |
779 | tlb_end_vma(&tlb, vma); | |
ac46d4f3 | 780 | mmu_notifier_invalidate_range_end(&range); |
ae8eba8b | 781 | tlb_finish_mmu(&tlb); |
854e9ed0 MK |
782 | |
783 | return 0; | |
784 | } | |
785 | ||
1da177e4 LT |
786 | /* |
787 | * Application no longer needs these pages. If the pages are dirty, | |
788 | * it's OK to just throw them away. The app will be more careful about | |
789 | * data it wants to keep. Be sure to free swap resources too. The | |
21b85b09 MK |
790 | * zap_page_range_single call sets things up for shrink_active_list to actually |
791 | * free these pages later if no one else has touched them in the meantime, | |
1da177e4 | 792 | * although we could add these pages to a global reuse list for |
7e6cbea3 | 793 | * shrink_active_list to pick up before reclaiming other pages. |
1da177e4 LT |
794 | * |
795 | * NB: This interface discards data rather than pushes it out to swap, | |
796 | * as some implementations do. This has performance implications for | |
797 | * applications like large transactional databases which want to discard | |
798 | * pages in anonymous maps after committing to backing store the data | |
799 | * that was kept in them. There is no reason to write this data out to | |
800 | * the swap area if the application is discarding it. | |
801 | * | |
802 | * An interface that causes the system to free clean pages and flush | |
803 | * dirty pages is already available as msync(MS_INVALIDATE). | |
804 | */ | |
230ca982 MR |
805 | static long madvise_dontneed_single_vma(struct vm_area_struct *vma, |
806 | unsigned long start, unsigned long end) | |
807 | { | |
21b85b09 | 808 | zap_page_range_single(vma, start, end - start, NULL); |
230ca982 MR |
809 | return 0; |
810 | } | |
811 | ||
90e7e7f5 MK |
812 | static bool madvise_dontneed_free_valid_vma(struct vm_area_struct *vma, |
813 | unsigned long start, | |
814 | unsigned long *end, | |
815 | int behavior) | |
816 | { | |
9457056a JW |
817 | if (!is_vm_hugetlb_page(vma)) { |
818 | unsigned int forbidden = VM_PFNMAP; | |
819 | ||
820 | if (behavior != MADV_DONTNEED_LOCKED) | |
821 | forbidden |= VM_LOCKED; | |
822 | ||
823 | return !(vma->vm_flags & forbidden); | |
824 | } | |
90e7e7f5 | 825 | |
9457056a | 826 | if (behavior != MADV_DONTNEED && behavior != MADV_DONTNEED_LOCKED) |
90e7e7f5 MK |
827 | return false; |
828 | if (start & ~huge_page_mask(hstate_vma(vma))) | |
829 | return false; | |
830 | ||
8ebe0a5e RR |
831 | /* |
832 | * Madvise callers expect the length to be rounded up to PAGE_SIZE | |
833 | * boundaries, and may be unaware that this VMA uses huge pages. | |
834 | * Avoid unexpected data loss by rounding down the number of | |
835 | * huge pages freed. | |
836 | */ | |
837 | *end = ALIGN_DOWN(*end, huge_page_size(hstate_vma(vma))); | |
838 | ||
90e7e7f5 MK |
839 | return true; |
840 | } | |
841 | ||
230ca982 MR |
842 | static long madvise_dontneed_free(struct vm_area_struct *vma, |
843 | struct vm_area_struct **prev, | |
844 | unsigned long start, unsigned long end, | |
845 | int behavior) | |
1da177e4 | 846 | { |
0726b01e MK |
847 | struct mm_struct *mm = vma->vm_mm; |
848 | ||
05b74384 | 849 | *prev = vma; |
90e7e7f5 | 850 | if (!madvise_dontneed_free_valid_vma(vma, start, &end, behavior)) |
1da177e4 LT |
851 | return -EINVAL; |
852 | ||
8ebe0a5e RR |
853 | if (start == end) |
854 | return 0; | |
855 | ||
70ccb92f | 856 | if (!userfaultfd_remove(vma, start, end)) { |
c1e8d7c6 | 857 | *prev = NULL; /* mmap_lock has been dropped, prev is stale */ |
70ccb92f | 858 | |
0726b01e MK |
859 | mmap_read_lock(mm); |
860 | vma = find_vma(mm, start); | |
70ccb92f AA |
861 | if (!vma) |
862 | return -ENOMEM; | |
863 | if (start < vma->vm_start) { | |
864 | /* | |
865 | * This "vma" under revalidation is the one | |
866 | * with the lowest vma->vm_start where start | |
867 | * is also < vma->vm_end. If start < | |
868 | * vma->vm_start it means an hole materialized | |
869 | * in the user address space within the | |
230ca982 MR |
870 | * virtual range passed to MADV_DONTNEED |
871 | * or MADV_FREE. | |
70ccb92f AA |
872 | */ |
873 | return -ENOMEM; | |
874 | } | |
90e7e7f5 MK |
875 | /* |
876 | * Potential end adjustment for hugetlb vma is OK as | |
877 | * the check below keeps end within vma. | |
878 | */ | |
879 | if (!madvise_dontneed_free_valid_vma(vma, start, &end, | |
880 | behavior)) | |
70ccb92f AA |
881 | return -EINVAL; |
882 | if (end > vma->vm_end) { | |
883 | /* | |
884 | * Don't fail if end > vma->vm_end. If the old | |
f0953a1b | 885 | * vma was split while the mmap_lock was |
70ccb92f | 886 | * released the effect of the concurrent |
230ca982 | 887 | * operation may not cause madvise() to |
70ccb92f AA |
888 | * have an undefined result. There may be an |
889 | * adjacent next vma that we'll walk | |
890 | * next. userfaultfd_remove() will generate an | |
891 | * UFFD_EVENT_REMOVE repetition on the | |
892 | * end-vma->vm_end range, but the manager can | |
893 | * handle a repetition fine. | |
894 | */ | |
895 | end = vma->vm_end; | |
896 | } | |
897 | VM_WARN_ON(start >= end); | |
898 | } | |
230ca982 | 899 | |
9457056a | 900 | if (behavior == MADV_DONTNEED || behavior == MADV_DONTNEED_LOCKED) |
230ca982 MR |
901 | return madvise_dontneed_single_vma(vma, start, end); |
902 | else if (behavior == MADV_FREE) | |
903 | return madvise_free_single_vma(vma, start, end); | |
904 | else | |
905 | return -EINVAL; | |
1da177e4 LT |
906 | } |
907 | ||
4ca9b385 DH |
908 | static long madvise_populate(struct vm_area_struct *vma, |
909 | struct vm_area_struct **prev, | |
910 | unsigned long start, unsigned long end, | |
911 | int behavior) | |
912 | { | |
913 | const bool write = behavior == MADV_POPULATE_WRITE; | |
914 | struct mm_struct *mm = vma->vm_mm; | |
915 | unsigned long tmp_end; | |
916 | int locked = 1; | |
917 | long pages; | |
918 | ||
919 | *prev = vma; | |
920 | ||
921 | while (start < end) { | |
922 | /* | |
923 | * We might have temporarily dropped the lock. For example, | |
924 | * our VMA might have been split. | |
925 | */ | |
926 | if (!vma || start >= vma->vm_end) { | |
531037a0 ML |
927 | vma = vma_lookup(mm, start); |
928 | if (!vma) | |
4ca9b385 DH |
929 | return -ENOMEM; |
930 | } | |
931 | ||
932 | tmp_end = min_t(unsigned long, end, vma->vm_end); | |
933 | /* Populate (prefault) page tables readable/writable. */ | |
934 | pages = faultin_vma_page_range(vma, start, tmp_end, write, | |
935 | &locked); | |
936 | if (!locked) { | |
937 | mmap_read_lock(mm); | |
938 | locked = 1; | |
939 | *prev = NULL; | |
940 | vma = NULL; | |
941 | } | |
942 | if (pages < 0) { | |
943 | switch (pages) { | |
944 | case -EINTR: | |
945 | return -EINTR; | |
eb2faa51 | 946 | case -EINVAL: /* Incompatible mappings / permissions. */ |
4ca9b385 DH |
947 | return -EINVAL; |
948 | case -EHWPOISON: | |
949 | return -EHWPOISON; | |
eb2faa51 DH |
950 | case -EFAULT: /* VM_FAULT_SIGBUS or VM_FAULT_SIGSEGV */ |
951 | return -EFAULT; | |
4ca9b385 DH |
952 | default: |
953 | pr_warn_once("%s: unhandled return value: %ld\n", | |
954 | __func__, pages); | |
955 | fallthrough; | |
956 | case -ENOMEM: | |
957 | return -ENOMEM; | |
958 | } | |
959 | } | |
960 | start += pages * PAGE_SIZE; | |
961 | } | |
962 | return 0; | |
963 | } | |
964 | ||
f6b3ec23 BP |
965 | /* |
966 | * Application wants to free up the pages and associated backing store. | |
967 | * This is effectively punching a hole into the middle of a file. | |
f6b3ec23 BP |
968 | */ |
969 | static long madvise_remove(struct vm_area_struct *vma, | |
00e9fa2d | 970 | struct vm_area_struct **prev, |
f6b3ec23 BP |
971 | unsigned long start, unsigned long end) |
972 | { | |
3f31d075 | 973 | loff_t offset; |
90ed52eb | 974 | int error; |
9ab4233d | 975 | struct file *f; |
0726b01e | 976 | struct mm_struct *mm = vma->vm_mm; |
f6b3ec23 | 977 | |
c1e8d7c6 | 978 | *prev = NULL; /* tell sys_madvise we drop mmap_lock */ |
00e9fa2d | 979 | |
72079ba0 | 980 | if (vma->vm_flags & VM_LOCKED) |
f6b3ec23 BP |
981 | return -EINVAL; |
982 | ||
9ab4233d AL |
983 | f = vma->vm_file; |
984 | ||
985 | if (!f || !f->f_mapping || !f->f_mapping->host) { | |
f6b3ec23 BP |
986 | return -EINVAL; |
987 | } | |
988 | ||
69cf0fac HD |
989 | if ((vma->vm_flags & (VM_SHARED|VM_WRITE)) != (VM_SHARED|VM_WRITE)) |
990 | return -EACCES; | |
991 | ||
f6b3ec23 BP |
992 | offset = (loff_t)(start - vma->vm_start) |
993 | + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); | |
90ed52eb | 994 | |
9ab4233d | 995 | /* |
9608703e | 996 | * Filesystem's fallocate may need to take i_rwsem. We need to |
9ab4233d AL |
997 | * explicitly grab a reference because the vma (and hence the |
998 | * vma's reference to the file) can go away as soon as we drop | |
c1e8d7c6 | 999 | * mmap_lock. |
9ab4233d AL |
1000 | */ |
1001 | get_file(f); | |
70ccb92f | 1002 | if (userfaultfd_remove(vma, start, end)) { |
c1e8d7c6 | 1003 | /* mmap_lock was not released by userfaultfd_remove() */ |
0726b01e | 1004 | mmap_read_unlock(mm); |
70ccb92f | 1005 | } |
72c72bdf | 1006 | error = vfs_fallocate(f, |
3f31d075 HD |
1007 | FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, |
1008 | offset, end - start); | |
9ab4233d | 1009 | fput(f); |
0726b01e | 1010 | mmap_read_lock(mm); |
90ed52eb | 1011 | return error; |
f6b3ec23 BP |
1012 | } |
1013 | ||
ac1e9acc CC |
1014 | /* |
1015 | * Apply an madvise behavior to a region of a vma. madvise_update_vma | |
1016 | * will handle splitting a vm area into separate areas, each area with its own | |
1017 | * behavior. | |
1018 | */ | |
1019 | static int madvise_vma_behavior(struct vm_area_struct *vma, | |
1020 | struct vm_area_struct **prev, | |
1021 | unsigned long start, unsigned long end, | |
1022 | unsigned long behavior) | |
1023 | { | |
1024 | int error; | |
942341dc | 1025 | struct anon_vma_name *anon_name; |
ac1e9acc CC |
1026 | unsigned long new_flags = vma->vm_flags; |
1027 | ||
1028 | switch (behavior) { | |
1029 | case MADV_REMOVE: | |
1030 | return madvise_remove(vma, prev, start, end); | |
1031 | case MADV_WILLNEED: | |
1032 | return madvise_willneed(vma, prev, start, end); | |
1033 | case MADV_COLD: | |
1034 | return madvise_cold(vma, prev, start, end); | |
1035 | case MADV_PAGEOUT: | |
1036 | return madvise_pageout(vma, prev, start, end); | |
1037 | case MADV_FREE: | |
1038 | case MADV_DONTNEED: | |
9457056a | 1039 | case MADV_DONTNEED_LOCKED: |
ac1e9acc CC |
1040 | return madvise_dontneed_free(vma, prev, start, end, behavior); |
1041 | case MADV_POPULATE_READ: | |
1042 | case MADV_POPULATE_WRITE: | |
1043 | return madvise_populate(vma, prev, start, end, behavior); | |
1044 | case MADV_NORMAL: | |
1045 | new_flags = new_flags & ~VM_RAND_READ & ~VM_SEQ_READ; | |
1046 | break; | |
1047 | case MADV_SEQUENTIAL: | |
1048 | new_flags = (new_flags & ~VM_RAND_READ) | VM_SEQ_READ; | |
1049 | break; | |
1050 | case MADV_RANDOM: | |
1051 | new_flags = (new_flags & ~VM_SEQ_READ) | VM_RAND_READ; | |
1052 | break; | |
1053 | case MADV_DONTFORK: | |
1054 | new_flags |= VM_DONTCOPY; | |
1055 | break; | |
1056 | case MADV_DOFORK: | |
1057 | if (vma->vm_flags & VM_IO) | |
1058 | return -EINVAL; | |
1059 | new_flags &= ~VM_DONTCOPY; | |
1060 | break; | |
1061 | case MADV_WIPEONFORK: | |
1062 | /* MADV_WIPEONFORK is only supported on anonymous memory. */ | |
1063 | if (vma->vm_file || vma->vm_flags & VM_SHARED) | |
1064 | return -EINVAL; | |
1065 | new_flags |= VM_WIPEONFORK; | |
1066 | break; | |
1067 | case MADV_KEEPONFORK: | |
1068 | new_flags &= ~VM_WIPEONFORK; | |
1069 | break; | |
1070 | case MADV_DONTDUMP: | |
1071 | new_flags |= VM_DONTDUMP; | |
1072 | break; | |
1073 | case MADV_DODUMP: | |
1074 | if (!is_vm_hugetlb_page(vma) && new_flags & VM_SPECIAL) | |
1075 | return -EINVAL; | |
1076 | new_flags &= ~VM_DONTDUMP; | |
1077 | break; | |
1078 | case MADV_MERGEABLE: | |
1079 | case MADV_UNMERGEABLE: | |
1080 | error = ksm_madvise(vma, start, end, behavior, &new_flags); | |
1081 | if (error) | |
1082 | goto out; | |
1083 | break; | |
1084 | case MADV_HUGEPAGE: | |
1085 | case MADV_NOHUGEPAGE: | |
1086 | error = hugepage_madvise(vma, &new_flags, behavior); | |
1087 | if (error) | |
1088 | goto out; | |
1089 | break; | |
7d8faaf1 ZK |
1090 | case MADV_COLLAPSE: |
1091 | return madvise_collapse(vma, prev, start, end); | |
ac1e9acc CC |
1092 | } |
1093 | ||
942341dc SB |
1094 | anon_name = anon_vma_name(vma); |
1095 | anon_vma_name_get(anon_name); | |
9a10064f | 1096 | error = madvise_update_vma(vma, prev, start, end, new_flags, |
942341dc SB |
1097 | anon_name); |
1098 | anon_vma_name_put(anon_name); | |
ac1e9acc CC |
1099 | |
1100 | out: | |
1101 | /* | |
1102 | * madvise() returns EAGAIN if kernel resources, such as | |
1103 | * slab, are temporarily unavailable. | |
1104 | */ | |
1105 | if (error == -ENOMEM) | |
1106 | error = -EAGAIN; | |
1107 | return error; | |
1108 | } | |
1109 | ||
9893e49d AK |
1110 | #ifdef CONFIG_MEMORY_FAILURE |
1111 | /* | |
1112 | * Error injection support for memory error handling. | |
1113 | */ | |
97167a76 AK |
1114 | static int madvise_inject_error(int behavior, |
1115 | unsigned long start, unsigned long end) | |
9893e49d | 1116 | { |
d3cd257c | 1117 | unsigned long size; |
97167a76 | 1118 | |
9893e49d AK |
1119 | if (!capable(CAP_SYS_ADMIN)) |
1120 | return -EPERM; | |
97167a76 | 1121 | |
19bfbe22 | 1122 | |
d3cd257c | 1123 | for (; start < end; start += size) { |
23e7b5c2 | 1124 | unsigned long pfn; |
dc7560b4 | 1125 | struct page *page; |
325c4ef5 AM |
1126 | int ret; |
1127 | ||
97167a76 | 1128 | ret = get_user_pages_fast(start, 1, 0, &page); |
9893e49d AK |
1129 | if (ret != 1) |
1130 | return ret; | |
23e7b5c2 | 1131 | pfn = page_to_pfn(page); |
325c4ef5 | 1132 | |
19bfbe22 AM |
1133 | /* |
1134 | * When soft offlining hugepages, after migrating the page | |
1135 | * we dissolve it, therefore in the second loop "page" will | |
d3cd257c | 1136 | * no longer be a compound page. |
19bfbe22 | 1137 | */ |
d3cd257c | 1138 | size = page_size(compound_head(page)); |
19bfbe22 | 1139 | |
97167a76 AK |
1140 | if (behavior == MADV_SOFT_OFFLINE) { |
1141 | pr_info("Soft offlining pfn %#lx at process virtual address %#lx\n", | |
dc7560b4 | 1142 | pfn, start); |
feec24a6 | 1143 | ret = soft_offline_page(pfn, MF_COUNT_INCREASED); |
dc7560b4 OS |
1144 | } else { |
1145 | pr_info("Injecting memory failure for pfn %#lx at process virtual address %#lx\n", | |
1146 | pfn, start); | |
67f22ba7 | 1147 | ret = memory_failure(pfn, MF_COUNT_INCREASED | MF_SW_SIMULATED); |
d1fe111f | 1148 | if (ret == -EOPNOTSUPP) |
1149 | ret = 0; | |
afcf938e | 1150 | } |
23e7b5c2 | 1151 | |
23a003bf NH |
1152 | if (ret) |
1153 | return ret; | |
9893e49d | 1154 | } |
c461ad6a | 1155 | |
325c4ef5 | 1156 | return 0; |
9893e49d AK |
1157 | } |
1158 | #endif | |
1159 | ||
1ecef9ed | 1160 | static bool |
75927af8 NP |
1161 | madvise_behavior_valid(int behavior) |
1162 | { | |
1163 | switch (behavior) { | |
1164 | case MADV_DOFORK: | |
1165 | case MADV_DONTFORK: | |
1166 | case MADV_NORMAL: | |
1167 | case MADV_SEQUENTIAL: | |
1168 | case MADV_RANDOM: | |
1169 | case MADV_REMOVE: | |
1170 | case MADV_WILLNEED: | |
1171 | case MADV_DONTNEED: | |
9457056a | 1172 | case MADV_DONTNEED_LOCKED: |
854e9ed0 | 1173 | case MADV_FREE: |
9c276cc6 | 1174 | case MADV_COLD: |
1a4e58cc | 1175 | case MADV_PAGEOUT: |
4ca9b385 DH |
1176 | case MADV_POPULATE_READ: |
1177 | case MADV_POPULATE_WRITE: | |
f8af4da3 HD |
1178 | #ifdef CONFIG_KSM |
1179 | case MADV_MERGEABLE: | |
1180 | case MADV_UNMERGEABLE: | |
0af4e98b AA |
1181 | #endif |
1182 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE | |
1183 | case MADV_HUGEPAGE: | |
a664b2d8 | 1184 | case MADV_NOHUGEPAGE: |
7d8faaf1 | 1185 | case MADV_COLLAPSE: |
f8af4da3 | 1186 | #endif |
accb61fe JB |
1187 | case MADV_DONTDUMP: |
1188 | case MADV_DODUMP: | |
d2cd9ede RR |
1189 | case MADV_WIPEONFORK: |
1190 | case MADV_KEEPONFORK: | |
5e451be7 AK |
1191 | #ifdef CONFIG_MEMORY_FAILURE |
1192 | case MADV_SOFT_OFFLINE: | |
1193 | case MADV_HWPOISON: | |
1194 | #endif | |
1ecef9ed | 1195 | return true; |
75927af8 NP |
1196 | |
1197 | default: | |
1ecef9ed | 1198 | return false; |
75927af8 NP |
1199 | } |
1200 | } | |
3866ea90 | 1201 | |
876b4a18 | 1202 | static bool process_madvise_behavior_valid(int behavior) |
ecb8ac8b MK |
1203 | { |
1204 | switch (behavior) { | |
1205 | case MADV_COLD: | |
1206 | case MADV_PAGEOUT: | |
d5fffc5a | 1207 | case MADV_WILLNEED: |
876b4a18 | 1208 | case MADV_COLLAPSE: |
ecb8ac8b MK |
1209 | return true; |
1210 | default: | |
1211 | return false; | |
1212 | } | |
1213 | } | |
1214 | ||
ac1e9acc CC |
1215 | /* |
1216 | * Walk the vmas in range [start,end), and call the visit function on each one. | |
1217 | * The visit function will get start and end parameters that cover the overlap | |
1218 | * between the current vma and the original range. Any unmapped regions in the | |
1219 | * original range will result in this function returning -ENOMEM while still | |
1220 | * calling the visit function on all of the existing vmas in the range. | |
1221 | * Must be called with the mmap_lock held for reading or writing. | |
1222 | */ | |
1223 | static | |
1224 | int madvise_walk_vmas(struct mm_struct *mm, unsigned long start, | |
1225 | unsigned long end, unsigned long arg, | |
1226 | int (*visit)(struct vm_area_struct *vma, | |
1227 | struct vm_area_struct **prev, unsigned long start, | |
1228 | unsigned long end, unsigned long arg)) | |
1229 | { | |
1230 | struct vm_area_struct *vma; | |
1231 | struct vm_area_struct *prev; | |
1232 | unsigned long tmp; | |
1233 | int unmapped_error = 0; | |
1234 | ||
1235 | /* | |
1236 | * If the interval [start,end) covers some unmapped address | |
1237 | * ranges, just ignore them, but return -ENOMEM at the end. | |
1238 | * - different from the way of handling in mlock etc. | |
1239 | */ | |
1240 | vma = find_vma_prev(mm, start, &prev); | |
1241 | if (vma && start > vma->vm_start) | |
1242 | prev = vma; | |
1243 | ||
1244 | for (;;) { | |
1245 | int error; | |
1246 | ||
1247 | /* Still start < end. */ | |
1248 | if (!vma) | |
1249 | return -ENOMEM; | |
1250 | ||
1251 | /* Here start < (end|vma->vm_end). */ | |
1252 | if (start < vma->vm_start) { | |
1253 | unmapped_error = -ENOMEM; | |
1254 | start = vma->vm_start; | |
1255 | if (start >= end) | |
1256 | break; | |
1257 | } | |
1258 | ||
1259 | /* Here vma->vm_start <= start < (end|vma->vm_end) */ | |
1260 | tmp = vma->vm_end; | |
1261 | if (end < tmp) | |
1262 | tmp = end; | |
1263 | ||
1264 | /* Here vma->vm_start <= start < tmp <= (end|vma->vm_end). */ | |
1265 | error = visit(vma, &prev, start, tmp, arg); | |
1266 | if (error) | |
1267 | return error; | |
1268 | start = tmp; | |
1269 | if (prev && start < prev->vm_end) | |
1270 | start = prev->vm_end; | |
1271 | if (start >= end) | |
1272 | break; | |
1273 | if (prev) | |
35474818 | 1274 | vma = find_vma(mm, prev->vm_end); |
ac1e9acc CC |
1275 | else /* madvise_remove dropped mmap_lock */ |
1276 | vma = find_vma(mm, start); | |
1277 | } | |
1278 | ||
1279 | return unmapped_error; | |
1280 | } | |
1281 | ||
9a10064f CC |
1282 | #ifdef CONFIG_ANON_VMA_NAME |
1283 | static int madvise_vma_anon_name(struct vm_area_struct *vma, | |
1284 | struct vm_area_struct **prev, | |
1285 | unsigned long start, unsigned long end, | |
5c26f6ac | 1286 | unsigned long anon_name) |
9a10064f CC |
1287 | { |
1288 | int error; | |
1289 | ||
1290 | /* Only anonymous mappings can be named */ | |
d09e8ca6 | 1291 | if (vma->vm_file && !vma_is_anon_shmem(vma)) |
9a10064f CC |
1292 | return -EBADF; |
1293 | ||
1294 | error = madvise_update_vma(vma, prev, start, end, vma->vm_flags, | |
5c26f6ac | 1295 | (struct anon_vma_name *)anon_name); |
9a10064f CC |
1296 | |
1297 | /* | |
1298 | * madvise() returns EAGAIN if kernel resources, such as | |
1299 | * slab, are temporarily unavailable. | |
1300 | */ | |
1301 | if (error == -ENOMEM) | |
1302 | error = -EAGAIN; | |
1303 | return error; | |
1304 | } | |
1305 | ||
1306 | int madvise_set_anon_name(struct mm_struct *mm, unsigned long start, | |
5c26f6ac | 1307 | unsigned long len_in, struct anon_vma_name *anon_name) |
9a10064f CC |
1308 | { |
1309 | unsigned long end; | |
1310 | unsigned long len; | |
1311 | ||
1312 | if (start & ~PAGE_MASK) | |
1313 | return -EINVAL; | |
1314 | len = (len_in + ~PAGE_MASK) & PAGE_MASK; | |
1315 | ||
1316 | /* Check to see whether len was rounded up from small -ve to zero */ | |
1317 | if (len_in && !len) | |
1318 | return -EINVAL; | |
1319 | ||
1320 | end = start + len; | |
1321 | if (end < start) | |
1322 | return -EINVAL; | |
1323 | ||
1324 | if (end == start) | |
1325 | return 0; | |
1326 | ||
5c26f6ac | 1327 | return madvise_walk_vmas(mm, start, end, (unsigned long)anon_name, |
9a10064f CC |
1328 | madvise_vma_anon_name); |
1329 | } | |
1330 | #endif /* CONFIG_ANON_VMA_NAME */ | |
1da177e4 LT |
1331 | /* |
1332 | * The madvise(2) system call. | |
1333 | * | |
1334 | * Applications can use madvise() to advise the kernel how it should | |
1335 | * handle paging I/O in this VM area. The idea is to help the kernel | |
1336 | * use appropriate read-ahead and caching techniques. The information | |
1337 | * provided is advisory only, and can be safely disregarded by the | |
1338 | * kernel without affecting the correct operation of the application. | |
1339 | * | |
1340 | * behavior values: | |
1341 | * MADV_NORMAL - the default behavior is to read clusters. This | |
1342 | * results in some read-ahead and read-behind. | |
1343 | * MADV_RANDOM - the system should read the minimum amount of data | |
1344 | * on any access, since it is unlikely that the appli- | |
1345 | * cation will need more than what it asks for. | |
1346 | * MADV_SEQUENTIAL - pages in the given range will probably be accessed | |
1347 | * once, so they can be aggressively read ahead, and | |
1348 | * can be freed soon after they are accessed. | |
1349 | * MADV_WILLNEED - the application is notifying the system to read | |
1350 | * some pages ahead. | |
1351 | * MADV_DONTNEED - the application is finished with the given range, | |
1352 | * so the kernel can free resources associated with it. | |
d7206a70 NH |
1353 | * MADV_FREE - the application marks pages in the given range as lazy free, |
1354 | * where actual purges are postponed until memory pressure happens. | |
f6b3ec23 BP |
1355 | * MADV_REMOVE - the application wants to free up the given range of |
1356 | * pages and associated backing store. | |
3866ea90 HD |
1357 | * MADV_DONTFORK - omit this area from child's address space when forking: |
1358 | * typically, to avoid COWing pages pinned by get_user_pages(). | |
1359 | * MADV_DOFORK - cancel MADV_DONTFORK: no longer omit this area when forking. | |
c02c3009 YS |
1360 | * MADV_WIPEONFORK - present the child process with zero-filled memory in this |
1361 | * range after a fork. | |
1362 | * MADV_KEEPONFORK - undo the effect of MADV_WIPEONFORK | |
d7206a70 NH |
1363 | * MADV_HWPOISON - trigger memory error handler as if the given memory range |
1364 | * were corrupted by unrecoverable hardware memory failure. | |
1365 | * MADV_SOFT_OFFLINE - try to soft-offline the given range of memory. | |
f8af4da3 HD |
1366 | * MADV_MERGEABLE - the application recommends that KSM try to merge pages in |
1367 | * this area with pages of identical content from other such areas. | |
1368 | * MADV_UNMERGEABLE- cancel MADV_MERGEABLE: no longer merge pages with others. | |
d7206a70 NH |
1369 | * MADV_HUGEPAGE - the application wants to back the given range by transparent |
1370 | * huge pages in the future. Existing pages might be coalesced and | |
1371 | * new pages might be allocated as THP. | |
1372 | * MADV_NOHUGEPAGE - mark the given range as not worth being backed by | |
1373 | * transparent huge pages so the existing pages will not be | |
1374 | * coalesced into THP and new pages will not be allocated as THP. | |
7d8faaf1 | 1375 | * MADV_COLLAPSE - synchronously coalesce pages into new THP. |
d7206a70 NH |
1376 | * MADV_DONTDUMP - the application wants to prevent pages in the given range |
1377 | * from being included in its core dump. | |
1378 | * MADV_DODUMP - cancel MADV_DONTDUMP: no longer exclude from core dump. | |
ecb8ac8b MK |
1379 | * MADV_COLD - the application is not expected to use this memory soon, |
1380 | * deactivate pages in this range so that they can be reclaimed | |
f0953a1b | 1381 | * easily if memory pressure happens. |
ecb8ac8b MK |
1382 | * MADV_PAGEOUT - the application is not expected to use this memory soon, |
1383 | * page out the pages in this range immediately. | |
4ca9b385 DH |
1384 | * MADV_POPULATE_READ - populate (prefault) page tables readable by |
1385 | * triggering read faults if required | |
1386 | * MADV_POPULATE_WRITE - populate (prefault) page tables writable by | |
1387 | * triggering write faults if required | |
1da177e4 LT |
1388 | * |
1389 | * return values: | |
1390 | * zero - success | |
1391 | * -EINVAL - start + len < 0, start is not page-aligned, | |
1392 | * "behavior" is not a valid value, or application | |
c02c3009 YS |
1393 | * is attempting to release locked or shared pages, |
1394 | * or the specified address range includes file, Huge TLB, | |
1395 | * MAP_SHARED or VMPFNMAP range. | |
1da177e4 LT |
1396 | * -ENOMEM - addresses in the specified range are not currently |
1397 | * mapped, or are outside the AS of the process. | |
1398 | * -EIO - an I/O error occurred while paging in data. | |
1399 | * -EBADF - map exists, but area maps something that isn't a file. | |
1400 | * -EAGAIN - a kernel resource was temporarily unavailable. | |
1401 | */ | |
0726b01e | 1402 | int do_madvise(struct mm_struct *mm, unsigned long start, size_t len_in, int behavior) |
1da177e4 | 1403 | { |
ac1e9acc CC |
1404 | unsigned long end; |
1405 | int error; | |
f7977793 | 1406 | int write; |
1da177e4 | 1407 | size_t len; |
1998cc04 | 1408 | struct blk_plug plug; |
1da177e4 | 1409 | |
057d3389 AK |
1410 | start = untagged_addr(start); |
1411 | ||
75927af8 | 1412 | if (!madvise_behavior_valid(behavior)) |
ac1e9acc | 1413 | return -EINVAL; |
75927af8 | 1414 | |
df6c6500 | 1415 | if (!PAGE_ALIGNED(start)) |
ac1e9acc | 1416 | return -EINVAL; |
df6c6500 | 1417 | len = PAGE_ALIGN(len_in); |
1da177e4 LT |
1418 | |
1419 | /* Check to see whether len was rounded up from small -ve to zero */ | |
1420 | if (len_in && !len) | |
ac1e9acc | 1421 | return -EINVAL; |
1da177e4 LT |
1422 | |
1423 | end = start + len; | |
1424 | if (end < start) | |
ac1e9acc | 1425 | return -EINVAL; |
1da177e4 | 1426 | |
1da177e4 | 1427 | if (end == start) |
ac1e9acc | 1428 | return 0; |
84d96d89 | 1429 | |
5e451be7 AK |
1430 | #ifdef CONFIG_MEMORY_FAILURE |
1431 | if (behavior == MADV_HWPOISON || behavior == MADV_SOFT_OFFLINE) | |
1432 | return madvise_inject_error(behavior, start, start + len_in); | |
1433 | #endif | |
1434 | ||
84d96d89 | 1435 | write = madvise_need_mmap_write(behavior); |
dc0ef0df | 1436 | if (write) { |
0726b01e | 1437 | if (mmap_write_lock_killable(mm)) |
dc0ef0df MH |
1438 | return -EINTR; |
1439 | } else { | |
0726b01e | 1440 | mmap_read_lock(mm); |
dc0ef0df | 1441 | } |
1da177e4 | 1442 | |
1998cc04 | 1443 | blk_start_plug(&plug); |
ac1e9acc CC |
1444 | error = madvise_walk_vmas(mm, start, end, behavior, |
1445 | madvise_vma_behavior); | |
84d96d89 | 1446 | blk_finish_plug(&plug); |
f7977793 | 1447 | if (write) |
0726b01e | 1448 | mmap_write_unlock(mm); |
0a27a14a | 1449 | else |
0726b01e | 1450 | mmap_read_unlock(mm); |
0a27a14a | 1451 | |
1da177e4 LT |
1452 | return error; |
1453 | } | |
db08ca25 JA |
1454 | |
1455 | SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior) | |
1456 | { | |
0726b01e | 1457 | return do_madvise(current->mm, start, len_in, behavior); |
db08ca25 | 1458 | } |
ecb8ac8b MK |
1459 | |
1460 | SYSCALL_DEFINE5(process_madvise, int, pidfd, const struct iovec __user *, vec, | |
1461 | size_t, vlen, int, behavior, unsigned int, flags) | |
1462 | { | |
1463 | ssize_t ret; | |
1464 | struct iovec iovstack[UIO_FASTIOV], iovec; | |
1465 | struct iovec *iov = iovstack; | |
1466 | struct iov_iter iter; | |
ecb8ac8b MK |
1467 | struct task_struct *task; |
1468 | struct mm_struct *mm; | |
1469 | size_t total_len; | |
1470 | unsigned int f_flags; | |
1471 | ||
1472 | if (flags != 0) { | |
1473 | ret = -EINVAL; | |
1474 | goto out; | |
1475 | } | |
1476 | ||
de4eda9d | 1477 | ret = import_iovec(ITER_DEST, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter); |
ecb8ac8b MK |
1478 | if (ret < 0) |
1479 | goto out; | |
1480 | ||
ee9955d6 CB |
1481 | task = pidfd_get_task(pidfd, &f_flags); |
1482 | if (IS_ERR(task)) { | |
1483 | ret = PTR_ERR(task); | |
ecb8ac8b MK |
1484 | goto free_iov; |
1485 | } | |
1486 | ||
a68a0262 | 1487 | if (!process_madvise_behavior_valid(behavior)) { |
ecb8ac8b MK |
1488 | ret = -EINVAL; |
1489 | goto release_task; | |
1490 | } | |
1491 | ||
96cfe2c0 SB |
1492 | /* Require PTRACE_MODE_READ to avoid leaking ASLR metadata. */ |
1493 | mm = mm_access(task, PTRACE_MODE_READ_FSCREDS); | |
ecb8ac8b MK |
1494 | if (IS_ERR_OR_NULL(mm)) { |
1495 | ret = IS_ERR(mm) ? PTR_ERR(mm) : -ESRCH; | |
1496 | goto release_task; | |
1497 | } | |
1498 | ||
96cfe2c0 SB |
1499 | /* |
1500 | * Require CAP_SYS_NICE for influencing process performance. Note that | |
1501 | * only non-destructive hints are currently supported. | |
1502 | */ | |
1503 | if (!capable(CAP_SYS_NICE)) { | |
1504 | ret = -EPERM; | |
1505 | goto release_mm; | |
1506 | } | |
1507 | ||
ecb8ac8b MK |
1508 | total_len = iov_iter_count(&iter); |
1509 | ||
1510 | while (iov_iter_count(&iter)) { | |
1511 | iovec = iov_iter_iovec(&iter); | |
1512 | ret = do_madvise(mm, (unsigned long)iovec.iov_base, | |
1513 | iovec.iov_len, behavior); | |
e6b0a7b3 | 1514 | if (ret < 0) |
ecb8ac8b MK |
1515 | break; |
1516 | iov_iter_advance(&iter, iovec.iov_len); | |
1517 | } | |
1518 | ||
5bd009c7 | 1519 | ret = (total_len - iov_iter_count(&iter)) ? : ret; |
ecb8ac8b | 1520 | |
96cfe2c0 | 1521 | release_mm: |
ecb8ac8b | 1522 | mmput(mm); |
ecb8ac8b MK |
1523 | release_task: |
1524 | put_task_struct(task); | |
ecb8ac8b MK |
1525 | free_iov: |
1526 | kfree(iov); | |
1527 | out: | |
1528 | return ret; | |
1529 | } |