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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/mm/memory.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds | |
5 | */ | |
6 | ||
7 | /* | |
8 | * demand-loading started 01.12.91 - seems it is high on the list of | |
9 | * things wanted, and it should be easy to implement. - Linus | |
10 | */ | |
11 | ||
12 | /* | |
13 | * Ok, demand-loading was easy, shared pages a little bit tricker. Shared | |
14 | * pages started 02.12.91, seems to work. - Linus. | |
15 | * | |
16 | * Tested sharing by executing about 30 /bin/sh: under the old kernel it | |
17 | * would have taken more than the 6M I have free, but it worked well as | |
18 | * far as I could see. | |
19 | * | |
20 | * Also corrected some "invalidate()"s - I wasn't doing enough of them. | |
21 | */ | |
22 | ||
23 | /* | |
24 | * Real VM (paging to/from disk) started 18.12.91. Much more work and | |
25 | * thought has to go into this. Oh, well.. | |
26 | * 19.12.91 - works, somewhat. Sometimes I get faults, don't know why. | |
27 | * Found it. Everything seems to work now. | |
28 | * 20.12.91 - Ok, making the swap-device changeable like the root. | |
29 | */ | |
30 | ||
31 | /* | |
32 | * 05.04.94 - Multi-page memory management added for v1.1. | |
33 | * Idea by Alex Bligh (alex@cconcepts.co.uk) | |
34 | * | |
35 | * 16.07.99 - Support of BIGMEM added by Gerhard Wichert, Siemens AG | |
36 | * (Gerhard.Wichert@pdb.siemens.de) | |
37 | * | |
38 | * Aug/Sep 2004 Changed to four level page tables (Andi Kleen) | |
39 | */ | |
40 | ||
41 | #include <linux/kernel_stat.h> | |
42 | #include <linux/mm.h> | |
43 | #include <linux/hugetlb.h> | |
44 | #include <linux/mman.h> | |
45 | #include <linux/swap.h> | |
46 | #include <linux/highmem.h> | |
47 | #include <linux/pagemap.h> | |
9a840895 | 48 | #include <linux/ksm.h> |
1da177e4 | 49 | #include <linux/rmap.h> |
b95f1b31 | 50 | #include <linux/export.h> |
0ff92245 | 51 | #include <linux/delayacct.h> |
1da177e4 | 52 | #include <linux/init.h> |
edc79b2a | 53 | #include <linux/writeback.h> |
8a9f3ccd | 54 | #include <linux/memcontrol.h> |
cddb8a5c | 55 | #include <linux/mmu_notifier.h> |
3dc14741 HD |
56 | #include <linux/kallsyms.h> |
57 | #include <linux/swapops.h> | |
58 | #include <linux/elf.h> | |
5a0e3ad6 | 59 | #include <linux/gfp.h> |
4daae3b4 | 60 | #include <linux/migrate.h> |
2fbc57c5 | 61 | #include <linux/string.h> |
0abdd7a8 | 62 | #include <linux/dma-debug.h> |
1592eef0 | 63 | #include <linux/debugfs.h> |
6b251fc9 | 64 | #include <linux/userfaultfd_k.h> |
1da177e4 | 65 | |
6952b61d | 66 | #include <asm/io.h> |
1da177e4 LT |
67 | #include <asm/pgalloc.h> |
68 | #include <asm/uaccess.h> | |
69 | #include <asm/tlb.h> | |
70 | #include <asm/tlbflush.h> | |
71 | #include <asm/pgtable.h> | |
72 | ||
42b77728 JB |
73 | #include "internal.h" |
74 | ||
90572890 PZ |
75 | #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS |
76 | #warning Unfortunate NUMA and NUMA Balancing config, growing page-frame for last_cpupid. | |
75980e97 PZ |
77 | #endif |
78 | ||
d41dee36 | 79 | #ifndef CONFIG_NEED_MULTIPLE_NODES |
1da177e4 LT |
80 | /* use the per-pgdat data instead for discontigmem - mbligh */ |
81 | unsigned long max_mapnr; | |
82 | struct page *mem_map; | |
83 | ||
84 | EXPORT_SYMBOL(max_mapnr); | |
85 | EXPORT_SYMBOL(mem_map); | |
86 | #endif | |
87 | ||
1da177e4 LT |
88 | /* |
89 | * A number of key systems in x86 including ioremap() rely on the assumption | |
90 | * that high_memory defines the upper bound on direct map memory, then end | |
91 | * of ZONE_NORMAL. Under CONFIG_DISCONTIG this means that max_low_pfn and | |
92 | * highstart_pfn must be the same; there must be no gap between ZONE_NORMAL | |
93 | * and ZONE_HIGHMEM. | |
94 | */ | |
95 | void * high_memory; | |
1da177e4 | 96 | |
1da177e4 | 97 | EXPORT_SYMBOL(high_memory); |
1da177e4 | 98 | |
32a93233 IM |
99 | /* |
100 | * Randomize the address space (stacks, mmaps, brk, etc.). | |
101 | * | |
102 | * ( When CONFIG_COMPAT_BRK=y we exclude brk from randomization, | |
103 | * as ancient (libc5 based) binaries can segfault. ) | |
104 | */ | |
105 | int randomize_va_space __read_mostly = | |
106 | #ifdef CONFIG_COMPAT_BRK | |
107 | 1; | |
108 | #else | |
109 | 2; | |
110 | #endif | |
a62eaf15 AK |
111 | |
112 | static int __init disable_randmaps(char *s) | |
113 | { | |
114 | randomize_va_space = 0; | |
9b41046c | 115 | return 1; |
a62eaf15 AK |
116 | } |
117 | __setup("norandmaps", disable_randmaps); | |
118 | ||
62eede62 | 119 | unsigned long zero_pfn __read_mostly; |
03f6462a | 120 | unsigned long highest_memmap_pfn __read_mostly; |
a13ea5b7 | 121 | |
0b70068e AB |
122 | EXPORT_SYMBOL(zero_pfn); |
123 | ||
a13ea5b7 HD |
124 | /* |
125 | * CONFIG_MMU architectures set up ZERO_PAGE in their paging_init() | |
126 | */ | |
127 | static int __init init_zero_pfn(void) | |
128 | { | |
129 | zero_pfn = page_to_pfn(ZERO_PAGE(0)); | |
130 | return 0; | |
131 | } | |
132 | core_initcall(init_zero_pfn); | |
a62eaf15 | 133 | |
d559db08 | 134 | |
34e55232 KH |
135 | #if defined(SPLIT_RSS_COUNTING) |
136 | ||
ea48cf78 | 137 | void sync_mm_rss(struct mm_struct *mm) |
34e55232 KH |
138 | { |
139 | int i; | |
140 | ||
141 | for (i = 0; i < NR_MM_COUNTERS; i++) { | |
05af2e10 DR |
142 | if (current->rss_stat.count[i]) { |
143 | add_mm_counter(mm, i, current->rss_stat.count[i]); | |
144 | current->rss_stat.count[i] = 0; | |
34e55232 KH |
145 | } |
146 | } | |
05af2e10 | 147 | current->rss_stat.events = 0; |
34e55232 KH |
148 | } |
149 | ||
150 | static void add_mm_counter_fast(struct mm_struct *mm, int member, int val) | |
151 | { | |
152 | struct task_struct *task = current; | |
153 | ||
154 | if (likely(task->mm == mm)) | |
155 | task->rss_stat.count[member] += val; | |
156 | else | |
157 | add_mm_counter(mm, member, val); | |
158 | } | |
159 | #define inc_mm_counter_fast(mm, member) add_mm_counter_fast(mm, member, 1) | |
160 | #define dec_mm_counter_fast(mm, member) add_mm_counter_fast(mm, member, -1) | |
161 | ||
162 | /* sync counter once per 64 page faults */ | |
163 | #define TASK_RSS_EVENTS_THRESH (64) | |
164 | static void check_sync_rss_stat(struct task_struct *task) | |
165 | { | |
166 | if (unlikely(task != current)) | |
167 | return; | |
168 | if (unlikely(task->rss_stat.events++ > TASK_RSS_EVENTS_THRESH)) | |
ea48cf78 | 169 | sync_mm_rss(task->mm); |
34e55232 | 170 | } |
9547d01b | 171 | #else /* SPLIT_RSS_COUNTING */ |
34e55232 KH |
172 | |
173 | #define inc_mm_counter_fast(mm, member) inc_mm_counter(mm, member) | |
174 | #define dec_mm_counter_fast(mm, member) dec_mm_counter(mm, member) | |
175 | ||
176 | static void check_sync_rss_stat(struct task_struct *task) | |
177 | { | |
178 | } | |
179 | ||
9547d01b PZ |
180 | #endif /* SPLIT_RSS_COUNTING */ |
181 | ||
182 | #ifdef HAVE_GENERIC_MMU_GATHER | |
183 | ||
ca1d6c7d | 184 | static bool tlb_next_batch(struct mmu_gather *tlb) |
9547d01b PZ |
185 | { |
186 | struct mmu_gather_batch *batch; | |
187 | ||
188 | batch = tlb->active; | |
189 | if (batch->next) { | |
190 | tlb->active = batch->next; | |
ca1d6c7d | 191 | return true; |
9547d01b PZ |
192 | } |
193 | ||
53a59fc6 | 194 | if (tlb->batch_count == MAX_GATHER_BATCH_COUNT) |
ca1d6c7d | 195 | return false; |
53a59fc6 | 196 | |
9547d01b PZ |
197 | batch = (void *)__get_free_pages(GFP_NOWAIT | __GFP_NOWARN, 0); |
198 | if (!batch) | |
ca1d6c7d | 199 | return false; |
9547d01b | 200 | |
53a59fc6 | 201 | tlb->batch_count++; |
9547d01b PZ |
202 | batch->next = NULL; |
203 | batch->nr = 0; | |
204 | batch->max = MAX_GATHER_BATCH; | |
205 | ||
206 | tlb->active->next = batch; | |
207 | tlb->active = batch; | |
208 | ||
ca1d6c7d | 209 | return true; |
9547d01b PZ |
210 | } |
211 | ||
212 | /* tlb_gather_mmu | |
213 | * Called to initialize an (on-stack) mmu_gather structure for page-table | |
214 | * tear-down from @mm. The @fullmm argument is used when @mm is without | |
215 | * users and we're going to destroy the full address space (exit/execve). | |
216 | */ | |
2b047252 | 217 | void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, unsigned long start, unsigned long end) |
9547d01b PZ |
218 | { |
219 | tlb->mm = mm; | |
220 | ||
2b047252 LT |
221 | /* Is it from 0 to ~0? */ |
222 | tlb->fullmm = !(start | (end+1)); | |
1de14c3c | 223 | tlb->need_flush_all = 0; |
9547d01b PZ |
224 | tlb->local.next = NULL; |
225 | tlb->local.nr = 0; | |
226 | tlb->local.max = ARRAY_SIZE(tlb->__pages); | |
227 | tlb->active = &tlb->local; | |
53a59fc6 | 228 | tlb->batch_count = 0; |
9547d01b PZ |
229 | |
230 | #ifdef CONFIG_HAVE_RCU_TABLE_FREE | |
231 | tlb->batch = NULL; | |
232 | #endif | |
fb7332a9 WD |
233 | |
234 | __tlb_reset_range(tlb); | |
9547d01b PZ |
235 | } |
236 | ||
1cf35d47 | 237 | static void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb) |
9547d01b | 238 | { |
721c21c1 WD |
239 | if (!tlb->end) |
240 | return; | |
241 | ||
9547d01b | 242 | tlb_flush(tlb); |
34ee645e | 243 | mmu_notifier_invalidate_range(tlb->mm, tlb->start, tlb->end); |
9547d01b PZ |
244 | #ifdef CONFIG_HAVE_RCU_TABLE_FREE |
245 | tlb_table_flush(tlb); | |
34e55232 | 246 | #endif |
fb7332a9 | 247 | __tlb_reset_range(tlb); |
1cf35d47 LT |
248 | } |
249 | ||
250 | static void tlb_flush_mmu_free(struct mmu_gather *tlb) | |
251 | { | |
252 | struct mmu_gather_batch *batch; | |
34e55232 | 253 | |
721c21c1 | 254 | for (batch = &tlb->local; batch && batch->nr; batch = batch->next) { |
9547d01b PZ |
255 | free_pages_and_swap_cache(batch->pages, batch->nr); |
256 | batch->nr = 0; | |
257 | } | |
258 | tlb->active = &tlb->local; | |
259 | } | |
260 | ||
1cf35d47 LT |
261 | void tlb_flush_mmu(struct mmu_gather *tlb) |
262 | { | |
1cf35d47 LT |
263 | tlb_flush_mmu_tlbonly(tlb); |
264 | tlb_flush_mmu_free(tlb); | |
265 | } | |
266 | ||
9547d01b PZ |
267 | /* tlb_finish_mmu |
268 | * Called at the end of the shootdown operation to free up any resources | |
269 | * that were required. | |
270 | */ | |
271 | void tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end) | |
272 | { | |
273 | struct mmu_gather_batch *batch, *next; | |
274 | ||
275 | tlb_flush_mmu(tlb); | |
276 | ||
277 | /* keep the page table cache within bounds */ | |
278 | check_pgt_cache(); | |
279 | ||
280 | for (batch = tlb->local.next; batch; batch = next) { | |
281 | next = batch->next; | |
282 | free_pages((unsigned long)batch, 0); | |
283 | } | |
284 | tlb->local.next = NULL; | |
285 | } | |
286 | ||
287 | /* __tlb_remove_page | |
288 | * Must perform the equivalent to __free_pte(pte_get_and_clear(ptep)), while | |
289 | * handling the additional races in SMP caused by other CPUs caching valid | |
290 | * mappings in their TLBs. Returns the number of free page slots left. | |
291 | * When out of page slots we must call tlb_flush_mmu(). | |
292 | */ | |
293 | int __tlb_remove_page(struct mmu_gather *tlb, struct page *page) | |
294 | { | |
295 | struct mmu_gather_batch *batch; | |
296 | ||
fb7332a9 | 297 | VM_BUG_ON(!tlb->end); |
9547d01b | 298 | |
9547d01b PZ |
299 | batch = tlb->active; |
300 | batch->pages[batch->nr++] = page; | |
301 | if (batch->nr == batch->max) { | |
302 | if (!tlb_next_batch(tlb)) | |
303 | return 0; | |
0b43c3aa | 304 | batch = tlb->active; |
9547d01b | 305 | } |
309381fe | 306 | VM_BUG_ON_PAGE(batch->nr > batch->max, page); |
9547d01b PZ |
307 | |
308 | return batch->max - batch->nr; | |
309 | } | |
310 | ||
311 | #endif /* HAVE_GENERIC_MMU_GATHER */ | |
312 | ||
26723911 PZ |
313 | #ifdef CONFIG_HAVE_RCU_TABLE_FREE |
314 | ||
315 | /* | |
316 | * See the comment near struct mmu_table_batch. | |
317 | */ | |
318 | ||
319 | static void tlb_remove_table_smp_sync(void *arg) | |
320 | { | |
321 | /* Simply deliver the interrupt */ | |
322 | } | |
323 | ||
324 | static void tlb_remove_table_one(void *table) | |
325 | { | |
326 | /* | |
327 | * This isn't an RCU grace period and hence the page-tables cannot be | |
328 | * assumed to be actually RCU-freed. | |
329 | * | |
330 | * It is however sufficient for software page-table walkers that rely on | |
331 | * IRQ disabling. See the comment near struct mmu_table_batch. | |
332 | */ | |
333 | smp_call_function(tlb_remove_table_smp_sync, NULL, 1); | |
334 | __tlb_remove_table(table); | |
335 | } | |
336 | ||
337 | static void tlb_remove_table_rcu(struct rcu_head *head) | |
338 | { | |
339 | struct mmu_table_batch *batch; | |
340 | int i; | |
341 | ||
342 | batch = container_of(head, struct mmu_table_batch, rcu); | |
343 | ||
344 | for (i = 0; i < batch->nr; i++) | |
345 | __tlb_remove_table(batch->tables[i]); | |
346 | ||
347 | free_page((unsigned long)batch); | |
348 | } | |
349 | ||
350 | void tlb_table_flush(struct mmu_gather *tlb) | |
351 | { | |
352 | struct mmu_table_batch **batch = &tlb->batch; | |
353 | ||
354 | if (*batch) { | |
355 | call_rcu_sched(&(*batch)->rcu, tlb_remove_table_rcu); | |
356 | *batch = NULL; | |
357 | } | |
358 | } | |
359 | ||
360 | void tlb_remove_table(struct mmu_gather *tlb, void *table) | |
361 | { | |
362 | struct mmu_table_batch **batch = &tlb->batch; | |
363 | ||
26723911 PZ |
364 | /* |
365 | * When there's less then two users of this mm there cannot be a | |
366 | * concurrent page-table walk. | |
367 | */ | |
368 | if (atomic_read(&tlb->mm->mm_users) < 2) { | |
369 | __tlb_remove_table(table); | |
370 | return; | |
371 | } | |
372 | ||
373 | if (*batch == NULL) { | |
374 | *batch = (struct mmu_table_batch *)__get_free_page(GFP_NOWAIT | __GFP_NOWARN); | |
375 | if (*batch == NULL) { | |
376 | tlb_remove_table_one(table); | |
377 | return; | |
378 | } | |
379 | (*batch)->nr = 0; | |
380 | } | |
381 | (*batch)->tables[(*batch)->nr++] = table; | |
382 | if ((*batch)->nr == MAX_TABLE_BATCH) | |
383 | tlb_table_flush(tlb); | |
384 | } | |
385 | ||
9547d01b | 386 | #endif /* CONFIG_HAVE_RCU_TABLE_FREE */ |
26723911 | 387 | |
1da177e4 LT |
388 | /* |
389 | * Note: this doesn't free the actual pages themselves. That | |
390 | * has been handled earlier when unmapping all the memory regions. | |
391 | */ | |
9e1b32ca BH |
392 | static void free_pte_range(struct mmu_gather *tlb, pmd_t *pmd, |
393 | unsigned long addr) | |
1da177e4 | 394 | { |
2f569afd | 395 | pgtable_t token = pmd_pgtable(*pmd); |
e0da382c | 396 | pmd_clear(pmd); |
9e1b32ca | 397 | pte_free_tlb(tlb, token, addr); |
e1f56c89 | 398 | atomic_long_dec(&tlb->mm->nr_ptes); |
1da177e4 LT |
399 | } |
400 | ||
e0da382c HD |
401 | static inline void free_pmd_range(struct mmu_gather *tlb, pud_t *pud, |
402 | unsigned long addr, unsigned long end, | |
403 | unsigned long floor, unsigned long ceiling) | |
1da177e4 LT |
404 | { |
405 | pmd_t *pmd; | |
406 | unsigned long next; | |
e0da382c | 407 | unsigned long start; |
1da177e4 | 408 | |
e0da382c | 409 | start = addr; |
1da177e4 | 410 | pmd = pmd_offset(pud, addr); |
1da177e4 LT |
411 | do { |
412 | next = pmd_addr_end(addr, end); | |
413 | if (pmd_none_or_clear_bad(pmd)) | |
414 | continue; | |
9e1b32ca | 415 | free_pte_range(tlb, pmd, addr); |
1da177e4 LT |
416 | } while (pmd++, addr = next, addr != end); |
417 | ||
e0da382c HD |
418 | start &= PUD_MASK; |
419 | if (start < floor) | |
420 | return; | |
421 | if (ceiling) { | |
422 | ceiling &= PUD_MASK; | |
423 | if (!ceiling) | |
424 | return; | |
1da177e4 | 425 | } |
e0da382c HD |
426 | if (end - 1 > ceiling - 1) |
427 | return; | |
428 | ||
429 | pmd = pmd_offset(pud, start); | |
430 | pud_clear(pud); | |
9e1b32ca | 431 | pmd_free_tlb(tlb, pmd, start); |
dc6c9a35 | 432 | mm_dec_nr_pmds(tlb->mm); |
1da177e4 LT |
433 | } |
434 | ||
e0da382c HD |
435 | static inline void free_pud_range(struct mmu_gather *tlb, pgd_t *pgd, |
436 | unsigned long addr, unsigned long end, | |
437 | unsigned long floor, unsigned long ceiling) | |
1da177e4 LT |
438 | { |
439 | pud_t *pud; | |
440 | unsigned long next; | |
e0da382c | 441 | unsigned long start; |
1da177e4 | 442 | |
e0da382c | 443 | start = addr; |
1da177e4 | 444 | pud = pud_offset(pgd, addr); |
1da177e4 LT |
445 | do { |
446 | next = pud_addr_end(addr, end); | |
447 | if (pud_none_or_clear_bad(pud)) | |
448 | continue; | |
e0da382c | 449 | free_pmd_range(tlb, pud, addr, next, floor, ceiling); |
1da177e4 LT |
450 | } while (pud++, addr = next, addr != end); |
451 | ||
e0da382c HD |
452 | start &= PGDIR_MASK; |
453 | if (start < floor) | |
454 | return; | |
455 | if (ceiling) { | |
456 | ceiling &= PGDIR_MASK; | |
457 | if (!ceiling) | |
458 | return; | |
1da177e4 | 459 | } |
e0da382c HD |
460 | if (end - 1 > ceiling - 1) |
461 | return; | |
462 | ||
463 | pud = pud_offset(pgd, start); | |
464 | pgd_clear(pgd); | |
9e1b32ca | 465 | pud_free_tlb(tlb, pud, start); |
1da177e4 LT |
466 | } |
467 | ||
468 | /* | |
e0da382c | 469 | * This function frees user-level page tables of a process. |
1da177e4 | 470 | */ |
42b77728 | 471 | void free_pgd_range(struct mmu_gather *tlb, |
e0da382c HD |
472 | unsigned long addr, unsigned long end, |
473 | unsigned long floor, unsigned long ceiling) | |
1da177e4 LT |
474 | { |
475 | pgd_t *pgd; | |
476 | unsigned long next; | |
e0da382c HD |
477 | |
478 | /* | |
479 | * The next few lines have given us lots of grief... | |
480 | * | |
481 | * Why are we testing PMD* at this top level? Because often | |
482 | * there will be no work to do at all, and we'd prefer not to | |
483 | * go all the way down to the bottom just to discover that. | |
484 | * | |
485 | * Why all these "- 1"s? Because 0 represents both the bottom | |
486 | * of the address space and the top of it (using -1 for the | |
487 | * top wouldn't help much: the masks would do the wrong thing). | |
488 | * The rule is that addr 0 and floor 0 refer to the bottom of | |
489 | * the address space, but end 0 and ceiling 0 refer to the top | |
490 | * Comparisons need to use "end - 1" and "ceiling - 1" (though | |
491 | * that end 0 case should be mythical). | |
492 | * | |
493 | * Wherever addr is brought up or ceiling brought down, we must | |
494 | * be careful to reject "the opposite 0" before it confuses the | |
495 | * subsequent tests. But what about where end is brought down | |
496 | * by PMD_SIZE below? no, end can't go down to 0 there. | |
497 | * | |
498 | * Whereas we round start (addr) and ceiling down, by different | |
499 | * masks at different levels, in order to test whether a table | |
500 | * now has no other vmas using it, so can be freed, we don't | |
501 | * bother to round floor or end up - the tests don't need that. | |
502 | */ | |
1da177e4 | 503 | |
e0da382c HD |
504 | addr &= PMD_MASK; |
505 | if (addr < floor) { | |
506 | addr += PMD_SIZE; | |
507 | if (!addr) | |
508 | return; | |
509 | } | |
510 | if (ceiling) { | |
511 | ceiling &= PMD_MASK; | |
512 | if (!ceiling) | |
513 | return; | |
514 | } | |
515 | if (end - 1 > ceiling - 1) | |
516 | end -= PMD_SIZE; | |
517 | if (addr > end - 1) | |
518 | return; | |
519 | ||
42b77728 | 520 | pgd = pgd_offset(tlb->mm, addr); |
1da177e4 LT |
521 | do { |
522 | next = pgd_addr_end(addr, end); | |
523 | if (pgd_none_or_clear_bad(pgd)) | |
524 | continue; | |
42b77728 | 525 | free_pud_range(tlb, pgd, addr, next, floor, ceiling); |
1da177e4 | 526 | } while (pgd++, addr = next, addr != end); |
e0da382c HD |
527 | } |
528 | ||
42b77728 | 529 | void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *vma, |
3bf5ee95 | 530 | unsigned long floor, unsigned long ceiling) |
e0da382c HD |
531 | { |
532 | while (vma) { | |
533 | struct vm_area_struct *next = vma->vm_next; | |
534 | unsigned long addr = vma->vm_start; | |
535 | ||
8f4f8c16 | 536 | /* |
25d9e2d1 | 537 | * Hide vma from rmap and truncate_pagecache before freeing |
538 | * pgtables | |
8f4f8c16 | 539 | */ |
5beb4930 | 540 | unlink_anon_vmas(vma); |
8f4f8c16 HD |
541 | unlink_file_vma(vma); |
542 | ||
9da61aef | 543 | if (is_vm_hugetlb_page(vma)) { |
3bf5ee95 | 544 | hugetlb_free_pgd_range(tlb, addr, vma->vm_end, |
e0da382c | 545 | floor, next? next->vm_start: ceiling); |
3bf5ee95 HD |
546 | } else { |
547 | /* | |
548 | * Optimization: gather nearby vmas into one call down | |
549 | */ | |
550 | while (next && next->vm_start <= vma->vm_end + PMD_SIZE | |
4866920b | 551 | && !is_vm_hugetlb_page(next)) { |
3bf5ee95 HD |
552 | vma = next; |
553 | next = vma->vm_next; | |
5beb4930 | 554 | unlink_anon_vmas(vma); |
8f4f8c16 | 555 | unlink_file_vma(vma); |
3bf5ee95 HD |
556 | } |
557 | free_pgd_range(tlb, addr, vma->vm_end, | |
558 | floor, next? next->vm_start: ceiling); | |
559 | } | |
e0da382c HD |
560 | vma = next; |
561 | } | |
1da177e4 LT |
562 | } |
563 | ||
8ac1f832 AA |
564 | int __pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma, |
565 | pmd_t *pmd, unsigned long address) | |
1da177e4 | 566 | { |
c4088ebd | 567 | spinlock_t *ptl; |
2f569afd | 568 | pgtable_t new = pte_alloc_one(mm, address); |
8ac1f832 | 569 | int wait_split_huge_page; |
1bb3630e HD |
570 | if (!new) |
571 | return -ENOMEM; | |
572 | ||
362a61ad NP |
573 | /* |
574 | * Ensure all pte setup (eg. pte page lock and page clearing) are | |
575 | * visible before the pte is made visible to other CPUs by being | |
576 | * put into page tables. | |
577 | * | |
578 | * The other side of the story is the pointer chasing in the page | |
579 | * table walking code (when walking the page table without locking; | |
580 | * ie. most of the time). Fortunately, these data accesses consist | |
581 | * of a chain of data-dependent loads, meaning most CPUs (alpha | |
582 | * being the notable exception) will already guarantee loads are | |
583 | * seen in-order. See the alpha page table accessors for the | |
584 | * smp_read_barrier_depends() barriers in page table walking code. | |
585 | */ | |
586 | smp_wmb(); /* Could be smp_wmb__xxx(before|after)_spin_lock */ | |
587 | ||
c4088ebd | 588 | ptl = pmd_lock(mm, pmd); |
8ac1f832 AA |
589 | wait_split_huge_page = 0; |
590 | if (likely(pmd_none(*pmd))) { /* Has another populated it ? */ | |
e1f56c89 | 591 | atomic_long_inc(&mm->nr_ptes); |
1da177e4 | 592 | pmd_populate(mm, pmd, new); |
2f569afd | 593 | new = NULL; |
8ac1f832 AA |
594 | } else if (unlikely(pmd_trans_splitting(*pmd))) |
595 | wait_split_huge_page = 1; | |
c4088ebd | 596 | spin_unlock(ptl); |
2f569afd MS |
597 | if (new) |
598 | pte_free(mm, new); | |
8ac1f832 AA |
599 | if (wait_split_huge_page) |
600 | wait_split_huge_page(vma->anon_vma, pmd); | |
1bb3630e | 601 | return 0; |
1da177e4 LT |
602 | } |
603 | ||
1bb3630e | 604 | int __pte_alloc_kernel(pmd_t *pmd, unsigned long address) |
1da177e4 | 605 | { |
1bb3630e HD |
606 | pte_t *new = pte_alloc_one_kernel(&init_mm, address); |
607 | if (!new) | |
608 | return -ENOMEM; | |
609 | ||
362a61ad NP |
610 | smp_wmb(); /* See comment in __pte_alloc */ |
611 | ||
1bb3630e | 612 | spin_lock(&init_mm.page_table_lock); |
8ac1f832 | 613 | if (likely(pmd_none(*pmd))) { /* Has another populated it ? */ |
1bb3630e | 614 | pmd_populate_kernel(&init_mm, pmd, new); |
2f569afd | 615 | new = NULL; |
8ac1f832 AA |
616 | } else |
617 | VM_BUG_ON(pmd_trans_splitting(*pmd)); | |
1bb3630e | 618 | spin_unlock(&init_mm.page_table_lock); |
2f569afd MS |
619 | if (new) |
620 | pte_free_kernel(&init_mm, new); | |
1bb3630e | 621 | return 0; |
1da177e4 LT |
622 | } |
623 | ||
d559db08 KH |
624 | static inline void init_rss_vec(int *rss) |
625 | { | |
626 | memset(rss, 0, sizeof(int) * NR_MM_COUNTERS); | |
627 | } | |
628 | ||
629 | static inline void add_mm_rss_vec(struct mm_struct *mm, int *rss) | |
ae859762 | 630 | { |
d559db08 KH |
631 | int i; |
632 | ||
34e55232 | 633 | if (current->mm == mm) |
05af2e10 | 634 | sync_mm_rss(mm); |
d559db08 KH |
635 | for (i = 0; i < NR_MM_COUNTERS; i++) |
636 | if (rss[i]) | |
637 | add_mm_counter(mm, i, rss[i]); | |
ae859762 HD |
638 | } |
639 | ||
b5810039 | 640 | /* |
6aab341e LT |
641 | * This function is called to print an error when a bad pte |
642 | * is found. For example, we might have a PFN-mapped pte in | |
643 | * a region that doesn't allow it. | |
b5810039 NP |
644 | * |
645 | * The calling function must still handle the error. | |
646 | */ | |
3dc14741 HD |
647 | static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr, |
648 | pte_t pte, struct page *page) | |
b5810039 | 649 | { |
3dc14741 HD |
650 | pgd_t *pgd = pgd_offset(vma->vm_mm, addr); |
651 | pud_t *pud = pud_offset(pgd, addr); | |
652 | pmd_t *pmd = pmd_offset(pud, addr); | |
653 | struct address_space *mapping; | |
654 | pgoff_t index; | |
d936cf9b HD |
655 | static unsigned long resume; |
656 | static unsigned long nr_shown; | |
657 | static unsigned long nr_unshown; | |
658 | ||
659 | /* | |
660 | * Allow a burst of 60 reports, then keep quiet for that minute; | |
661 | * or allow a steady drip of one report per second. | |
662 | */ | |
663 | if (nr_shown == 60) { | |
664 | if (time_before(jiffies, resume)) { | |
665 | nr_unshown++; | |
666 | return; | |
667 | } | |
668 | if (nr_unshown) { | |
1e9e6365 HD |
669 | printk(KERN_ALERT |
670 | "BUG: Bad page map: %lu messages suppressed\n", | |
d936cf9b HD |
671 | nr_unshown); |
672 | nr_unshown = 0; | |
673 | } | |
674 | nr_shown = 0; | |
675 | } | |
676 | if (nr_shown++ == 0) | |
677 | resume = jiffies + 60 * HZ; | |
3dc14741 HD |
678 | |
679 | mapping = vma->vm_file ? vma->vm_file->f_mapping : NULL; | |
680 | index = linear_page_index(vma, addr); | |
681 | ||
1e9e6365 HD |
682 | printk(KERN_ALERT |
683 | "BUG: Bad page map in process %s pte:%08llx pmd:%08llx\n", | |
3dc14741 HD |
684 | current->comm, |
685 | (long long)pte_val(pte), (long long)pmd_val(*pmd)); | |
718a3821 | 686 | if (page) |
f0b791a3 | 687 | dump_page(page, "bad pte"); |
1e9e6365 | 688 | printk(KERN_ALERT |
3dc14741 HD |
689 | "addr:%p vm_flags:%08lx anon_vma:%p mapping:%p index:%lx\n", |
690 | (void *)addr, vma->vm_flags, vma->anon_vma, mapping, index); | |
691 | /* | |
692 | * Choose text because data symbols depend on CONFIG_KALLSYMS_ALL=y | |
693 | */ | |
2682582a KK |
694 | pr_alert("file:%pD fault:%pf mmap:%pf readpage:%pf\n", |
695 | vma->vm_file, | |
696 | vma->vm_ops ? vma->vm_ops->fault : NULL, | |
697 | vma->vm_file ? vma->vm_file->f_op->mmap : NULL, | |
698 | mapping ? mapping->a_ops->readpage : NULL); | |
b5810039 | 699 | dump_stack(); |
373d4d09 | 700 | add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); |
b5810039 NP |
701 | } |
702 | ||
ee498ed7 | 703 | /* |
7e675137 | 704 | * vm_normal_page -- This function gets the "struct page" associated with a pte. |
6aab341e | 705 | * |
7e675137 NP |
706 | * "Special" mappings do not wish to be associated with a "struct page" (either |
707 | * it doesn't exist, or it exists but they don't want to touch it). In this | |
708 | * case, NULL is returned here. "Normal" mappings do have a struct page. | |
b379d790 | 709 | * |
7e675137 NP |
710 | * There are 2 broad cases. Firstly, an architecture may define a pte_special() |
711 | * pte bit, in which case this function is trivial. Secondly, an architecture | |
712 | * may not have a spare pte bit, which requires a more complicated scheme, | |
713 | * described below. | |
714 | * | |
715 | * A raw VM_PFNMAP mapping (ie. one that is not COWed) is always considered a | |
716 | * special mapping (even if there are underlying and valid "struct pages"). | |
717 | * COWed pages of a VM_PFNMAP are always normal. | |
6aab341e | 718 | * |
b379d790 JH |
719 | * The way we recognize COWed pages within VM_PFNMAP mappings is through the |
720 | * rules set up by "remap_pfn_range()": the vma will have the VM_PFNMAP bit | |
7e675137 NP |
721 | * set, and the vm_pgoff will point to the first PFN mapped: thus every special |
722 | * mapping will always honor the rule | |
6aab341e LT |
723 | * |
724 | * pfn_of_page == vma->vm_pgoff + ((addr - vma->vm_start) >> PAGE_SHIFT) | |
725 | * | |
7e675137 NP |
726 | * And for normal mappings this is false. |
727 | * | |
728 | * This restricts such mappings to be a linear translation from virtual address | |
729 | * to pfn. To get around this restriction, we allow arbitrary mappings so long | |
730 | * as the vma is not a COW mapping; in that case, we know that all ptes are | |
731 | * special (because none can have been COWed). | |
b379d790 | 732 | * |
b379d790 | 733 | * |
7e675137 | 734 | * In order to support COW of arbitrary special mappings, we have VM_MIXEDMAP. |
b379d790 JH |
735 | * |
736 | * VM_MIXEDMAP mappings can likewise contain memory with or without "struct | |
737 | * page" backing, however the difference is that _all_ pages with a struct | |
738 | * page (that is, those where pfn_valid is true) are refcounted and considered | |
739 | * normal pages by the VM. The disadvantage is that pages are refcounted | |
740 | * (which can be slower and simply not an option for some PFNMAP users). The | |
741 | * advantage is that we don't have to follow the strict linearity rule of | |
742 | * PFNMAP mappings in order to support COWable mappings. | |
743 | * | |
ee498ed7 | 744 | */ |
7e675137 NP |
745 | #ifdef __HAVE_ARCH_PTE_SPECIAL |
746 | # define HAVE_PTE_SPECIAL 1 | |
747 | #else | |
748 | # define HAVE_PTE_SPECIAL 0 | |
749 | #endif | |
750 | struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr, | |
751 | pte_t pte) | |
ee498ed7 | 752 | { |
22b31eec | 753 | unsigned long pfn = pte_pfn(pte); |
7e675137 NP |
754 | |
755 | if (HAVE_PTE_SPECIAL) { | |
b38af472 | 756 | if (likely(!pte_special(pte))) |
22b31eec | 757 | goto check_pfn; |
667a0a06 DV |
758 | if (vma->vm_ops && vma->vm_ops->find_special_page) |
759 | return vma->vm_ops->find_special_page(vma, addr); | |
a13ea5b7 HD |
760 | if (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP)) |
761 | return NULL; | |
62eede62 | 762 | if (!is_zero_pfn(pfn)) |
22b31eec | 763 | print_bad_pte(vma, addr, pte, NULL); |
7e675137 NP |
764 | return NULL; |
765 | } | |
766 | ||
767 | /* !HAVE_PTE_SPECIAL case follows: */ | |
768 | ||
b379d790 JH |
769 | if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) { |
770 | if (vma->vm_flags & VM_MIXEDMAP) { | |
771 | if (!pfn_valid(pfn)) | |
772 | return NULL; | |
773 | goto out; | |
774 | } else { | |
7e675137 NP |
775 | unsigned long off; |
776 | off = (addr - vma->vm_start) >> PAGE_SHIFT; | |
b379d790 JH |
777 | if (pfn == vma->vm_pgoff + off) |
778 | return NULL; | |
779 | if (!is_cow_mapping(vma->vm_flags)) | |
780 | return NULL; | |
781 | } | |
6aab341e LT |
782 | } |
783 | ||
b38af472 HD |
784 | if (is_zero_pfn(pfn)) |
785 | return NULL; | |
22b31eec HD |
786 | check_pfn: |
787 | if (unlikely(pfn > highest_memmap_pfn)) { | |
788 | print_bad_pte(vma, addr, pte, NULL); | |
789 | return NULL; | |
790 | } | |
6aab341e LT |
791 | |
792 | /* | |
7e675137 | 793 | * NOTE! We still have PageReserved() pages in the page tables. |
7e675137 | 794 | * eg. VDSO mappings can cause them to exist. |
6aab341e | 795 | */ |
b379d790 | 796 | out: |
6aab341e | 797 | return pfn_to_page(pfn); |
ee498ed7 HD |
798 | } |
799 | ||
1da177e4 LT |
800 | /* |
801 | * copy one vm_area from one task to the other. Assumes the page tables | |
802 | * already present in the new task to be cleared in the whole range | |
803 | * covered by this vma. | |
1da177e4 LT |
804 | */ |
805 | ||
570a335b | 806 | static inline unsigned long |
1da177e4 | 807 | copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm, |
b5810039 | 808 | pte_t *dst_pte, pte_t *src_pte, struct vm_area_struct *vma, |
8c103762 | 809 | unsigned long addr, int *rss) |
1da177e4 | 810 | { |
b5810039 | 811 | unsigned long vm_flags = vma->vm_flags; |
1da177e4 LT |
812 | pte_t pte = *src_pte; |
813 | struct page *page; | |
1da177e4 LT |
814 | |
815 | /* pte contains position in swap or file, so copy. */ | |
816 | if (unlikely(!pte_present(pte))) { | |
0661a336 KS |
817 | swp_entry_t entry = pte_to_swp_entry(pte); |
818 | ||
819 | if (likely(!non_swap_entry(entry))) { | |
820 | if (swap_duplicate(entry) < 0) | |
821 | return entry.val; | |
822 | ||
823 | /* make sure dst_mm is on swapoff's mmlist. */ | |
824 | if (unlikely(list_empty(&dst_mm->mmlist))) { | |
825 | spin_lock(&mmlist_lock); | |
826 | if (list_empty(&dst_mm->mmlist)) | |
827 | list_add(&dst_mm->mmlist, | |
828 | &src_mm->mmlist); | |
829 | spin_unlock(&mmlist_lock); | |
830 | } | |
831 | rss[MM_SWAPENTS]++; | |
832 | } else if (is_migration_entry(entry)) { | |
833 | page = migration_entry_to_page(entry); | |
834 | ||
835 | if (PageAnon(page)) | |
836 | rss[MM_ANONPAGES]++; | |
837 | else | |
838 | rss[MM_FILEPAGES]++; | |
839 | ||
840 | if (is_write_migration_entry(entry) && | |
841 | is_cow_mapping(vm_flags)) { | |
842 | /* | |
843 | * COW mappings require pages in both | |
844 | * parent and child to be set to read. | |
845 | */ | |
846 | make_migration_entry_read(&entry); | |
847 | pte = swp_entry_to_pte(entry); | |
848 | if (pte_swp_soft_dirty(*src_pte)) | |
849 | pte = pte_swp_mksoft_dirty(pte); | |
850 | set_pte_at(src_mm, addr, src_pte, pte); | |
0697212a | 851 | } |
1da177e4 | 852 | } |
ae859762 | 853 | goto out_set_pte; |
1da177e4 LT |
854 | } |
855 | ||
1da177e4 LT |
856 | /* |
857 | * If it's a COW mapping, write protect it both | |
858 | * in the parent and the child | |
859 | */ | |
67121172 | 860 | if (is_cow_mapping(vm_flags)) { |
1da177e4 | 861 | ptep_set_wrprotect(src_mm, addr, src_pte); |
3dc90795 | 862 | pte = pte_wrprotect(pte); |
1da177e4 LT |
863 | } |
864 | ||
865 | /* | |
866 | * If it's a shared mapping, mark it clean in | |
867 | * the child | |
868 | */ | |
869 | if (vm_flags & VM_SHARED) | |
870 | pte = pte_mkclean(pte); | |
871 | pte = pte_mkold(pte); | |
6aab341e LT |
872 | |
873 | page = vm_normal_page(vma, addr, pte); | |
874 | if (page) { | |
875 | get_page(page); | |
21333b2b | 876 | page_dup_rmap(page); |
d559db08 KH |
877 | if (PageAnon(page)) |
878 | rss[MM_ANONPAGES]++; | |
879 | else | |
880 | rss[MM_FILEPAGES]++; | |
6aab341e | 881 | } |
ae859762 HD |
882 | |
883 | out_set_pte: | |
884 | set_pte_at(dst_mm, addr, dst_pte, pte); | |
570a335b | 885 | return 0; |
1da177e4 LT |
886 | } |
887 | ||
21bda264 | 888 | static int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm, |
71e3aac0 AA |
889 | pmd_t *dst_pmd, pmd_t *src_pmd, struct vm_area_struct *vma, |
890 | unsigned long addr, unsigned long end) | |
1da177e4 | 891 | { |
c36987e2 | 892 | pte_t *orig_src_pte, *orig_dst_pte; |
1da177e4 | 893 | pte_t *src_pte, *dst_pte; |
c74df32c | 894 | spinlock_t *src_ptl, *dst_ptl; |
e040f218 | 895 | int progress = 0; |
d559db08 | 896 | int rss[NR_MM_COUNTERS]; |
570a335b | 897 | swp_entry_t entry = (swp_entry_t){0}; |
1da177e4 LT |
898 | |
899 | again: | |
d559db08 KH |
900 | init_rss_vec(rss); |
901 | ||
c74df32c | 902 | dst_pte = pte_alloc_map_lock(dst_mm, dst_pmd, addr, &dst_ptl); |
1da177e4 LT |
903 | if (!dst_pte) |
904 | return -ENOMEM; | |
ece0e2b6 | 905 | src_pte = pte_offset_map(src_pmd, addr); |
4c21e2f2 | 906 | src_ptl = pte_lockptr(src_mm, src_pmd); |
f20dc5f7 | 907 | spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); |
c36987e2 DN |
908 | orig_src_pte = src_pte; |
909 | orig_dst_pte = dst_pte; | |
6606c3e0 | 910 | arch_enter_lazy_mmu_mode(); |
1da177e4 | 911 | |
1da177e4 LT |
912 | do { |
913 | /* | |
914 | * We are holding two locks at this point - either of them | |
915 | * could generate latencies in another task on another CPU. | |
916 | */ | |
e040f218 HD |
917 | if (progress >= 32) { |
918 | progress = 0; | |
919 | if (need_resched() || | |
95c354fe | 920 | spin_needbreak(src_ptl) || spin_needbreak(dst_ptl)) |
e040f218 HD |
921 | break; |
922 | } | |
1da177e4 LT |
923 | if (pte_none(*src_pte)) { |
924 | progress++; | |
925 | continue; | |
926 | } | |
570a335b HD |
927 | entry.val = copy_one_pte(dst_mm, src_mm, dst_pte, src_pte, |
928 | vma, addr, rss); | |
929 | if (entry.val) | |
930 | break; | |
1da177e4 LT |
931 | progress += 8; |
932 | } while (dst_pte++, src_pte++, addr += PAGE_SIZE, addr != end); | |
1da177e4 | 933 | |
6606c3e0 | 934 | arch_leave_lazy_mmu_mode(); |
c74df32c | 935 | spin_unlock(src_ptl); |
ece0e2b6 | 936 | pte_unmap(orig_src_pte); |
d559db08 | 937 | add_mm_rss_vec(dst_mm, rss); |
c36987e2 | 938 | pte_unmap_unlock(orig_dst_pte, dst_ptl); |
c74df32c | 939 | cond_resched(); |
570a335b HD |
940 | |
941 | if (entry.val) { | |
942 | if (add_swap_count_continuation(entry, GFP_KERNEL) < 0) | |
943 | return -ENOMEM; | |
944 | progress = 0; | |
945 | } | |
1da177e4 LT |
946 | if (addr != end) |
947 | goto again; | |
948 | return 0; | |
949 | } | |
950 | ||
951 | static inline int copy_pmd_range(struct mm_struct *dst_mm, struct mm_struct *src_mm, | |
952 | pud_t *dst_pud, pud_t *src_pud, struct vm_area_struct *vma, | |
953 | unsigned long addr, unsigned long end) | |
954 | { | |
955 | pmd_t *src_pmd, *dst_pmd; | |
956 | unsigned long next; | |
957 | ||
958 | dst_pmd = pmd_alloc(dst_mm, dst_pud, addr); | |
959 | if (!dst_pmd) | |
960 | return -ENOMEM; | |
961 | src_pmd = pmd_offset(src_pud, addr); | |
962 | do { | |
963 | next = pmd_addr_end(addr, end); | |
71e3aac0 AA |
964 | if (pmd_trans_huge(*src_pmd)) { |
965 | int err; | |
14d1a55c | 966 | VM_BUG_ON(next-addr != HPAGE_PMD_SIZE); |
71e3aac0 AA |
967 | err = copy_huge_pmd(dst_mm, src_mm, |
968 | dst_pmd, src_pmd, addr, vma); | |
969 | if (err == -ENOMEM) | |
970 | return -ENOMEM; | |
971 | if (!err) | |
972 | continue; | |
973 | /* fall through */ | |
974 | } | |
1da177e4 LT |
975 | if (pmd_none_or_clear_bad(src_pmd)) |
976 | continue; | |
977 | if (copy_pte_range(dst_mm, src_mm, dst_pmd, src_pmd, | |
978 | vma, addr, next)) | |
979 | return -ENOMEM; | |
980 | } while (dst_pmd++, src_pmd++, addr = next, addr != end); | |
981 | return 0; | |
982 | } | |
983 | ||
984 | static inline int copy_pud_range(struct mm_struct *dst_mm, struct mm_struct *src_mm, | |
985 | pgd_t *dst_pgd, pgd_t *src_pgd, struct vm_area_struct *vma, | |
986 | unsigned long addr, unsigned long end) | |
987 | { | |
988 | pud_t *src_pud, *dst_pud; | |
989 | unsigned long next; | |
990 | ||
991 | dst_pud = pud_alloc(dst_mm, dst_pgd, addr); | |
992 | if (!dst_pud) | |
993 | return -ENOMEM; | |
994 | src_pud = pud_offset(src_pgd, addr); | |
995 | do { | |
996 | next = pud_addr_end(addr, end); | |
997 | if (pud_none_or_clear_bad(src_pud)) | |
998 | continue; | |
999 | if (copy_pmd_range(dst_mm, src_mm, dst_pud, src_pud, | |
1000 | vma, addr, next)) | |
1001 | return -ENOMEM; | |
1002 | } while (dst_pud++, src_pud++, addr = next, addr != end); | |
1003 | return 0; | |
1004 | } | |
1005 | ||
1006 | int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm, | |
1007 | struct vm_area_struct *vma) | |
1008 | { | |
1009 | pgd_t *src_pgd, *dst_pgd; | |
1010 | unsigned long next; | |
1011 | unsigned long addr = vma->vm_start; | |
1012 | unsigned long end = vma->vm_end; | |
2ec74c3e SG |
1013 | unsigned long mmun_start; /* For mmu_notifiers */ |
1014 | unsigned long mmun_end; /* For mmu_notifiers */ | |
1015 | bool is_cow; | |
cddb8a5c | 1016 | int ret; |
1da177e4 | 1017 | |
d992895b NP |
1018 | /* |
1019 | * Don't copy ptes where a page fault will fill them correctly. | |
1020 | * Fork becomes much lighter when there are big shared or private | |
1021 | * readonly mappings. The tradeoff is that copy_page_range is more | |
1022 | * efficient than faulting. | |
1023 | */ | |
0661a336 KS |
1024 | if (!(vma->vm_flags & (VM_HUGETLB | VM_PFNMAP | VM_MIXEDMAP)) && |
1025 | !vma->anon_vma) | |
1026 | return 0; | |
d992895b | 1027 | |
1da177e4 LT |
1028 | if (is_vm_hugetlb_page(vma)) |
1029 | return copy_hugetlb_page_range(dst_mm, src_mm, vma); | |
1030 | ||
b3b9c293 | 1031 | if (unlikely(vma->vm_flags & VM_PFNMAP)) { |
2ab64037 | 1032 | /* |
1033 | * We do not free on error cases below as remove_vma | |
1034 | * gets called on error from higher level routine | |
1035 | */ | |
5180da41 | 1036 | ret = track_pfn_copy(vma); |
2ab64037 | 1037 | if (ret) |
1038 | return ret; | |
1039 | } | |
1040 | ||
cddb8a5c AA |
1041 | /* |
1042 | * We need to invalidate the secondary MMU mappings only when | |
1043 | * there could be a permission downgrade on the ptes of the | |
1044 | * parent mm. And a permission downgrade will only happen if | |
1045 | * is_cow_mapping() returns true. | |
1046 | */ | |
2ec74c3e SG |
1047 | is_cow = is_cow_mapping(vma->vm_flags); |
1048 | mmun_start = addr; | |
1049 | mmun_end = end; | |
1050 | if (is_cow) | |
1051 | mmu_notifier_invalidate_range_start(src_mm, mmun_start, | |
1052 | mmun_end); | |
cddb8a5c AA |
1053 | |
1054 | ret = 0; | |
1da177e4 LT |
1055 | dst_pgd = pgd_offset(dst_mm, addr); |
1056 | src_pgd = pgd_offset(src_mm, addr); | |
1057 | do { | |
1058 | next = pgd_addr_end(addr, end); | |
1059 | if (pgd_none_or_clear_bad(src_pgd)) | |
1060 | continue; | |
cddb8a5c AA |
1061 | if (unlikely(copy_pud_range(dst_mm, src_mm, dst_pgd, src_pgd, |
1062 | vma, addr, next))) { | |
1063 | ret = -ENOMEM; | |
1064 | break; | |
1065 | } | |
1da177e4 | 1066 | } while (dst_pgd++, src_pgd++, addr = next, addr != end); |
cddb8a5c | 1067 | |
2ec74c3e SG |
1068 | if (is_cow) |
1069 | mmu_notifier_invalidate_range_end(src_mm, mmun_start, mmun_end); | |
cddb8a5c | 1070 | return ret; |
1da177e4 LT |
1071 | } |
1072 | ||
51c6f666 | 1073 | static unsigned long zap_pte_range(struct mmu_gather *tlb, |
b5810039 | 1074 | struct vm_area_struct *vma, pmd_t *pmd, |
1da177e4 | 1075 | unsigned long addr, unsigned long end, |
97a89413 | 1076 | struct zap_details *details) |
1da177e4 | 1077 | { |
b5810039 | 1078 | struct mm_struct *mm = tlb->mm; |
d16dfc55 | 1079 | int force_flush = 0; |
d559db08 | 1080 | int rss[NR_MM_COUNTERS]; |
97a89413 | 1081 | spinlock_t *ptl; |
5f1a1907 | 1082 | pte_t *start_pte; |
97a89413 | 1083 | pte_t *pte; |
8a5f14a2 | 1084 | swp_entry_t entry; |
d559db08 | 1085 | |
d16dfc55 | 1086 | again: |
e303297e | 1087 | init_rss_vec(rss); |
5f1a1907 SR |
1088 | start_pte = pte_offset_map_lock(mm, pmd, addr, &ptl); |
1089 | pte = start_pte; | |
6606c3e0 | 1090 | arch_enter_lazy_mmu_mode(); |
1da177e4 LT |
1091 | do { |
1092 | pte_t ptent = *pte; | |
51c6f666 | 1093 | if (pte_none(ptent)) { |
1da177e4 | 1094 | continue; |
51c6f666 | 1095 | } |
6f5e6b9e | 1096 | |
1da177e4 | 1097 | if (pte_present(ptent)) { |
ee498ed7 | 1098 | struct page *page; |
51c6f666 | 1099 | |
6aab341e | 1100 | page = vm_normal_page(vma, addr, ptent); |
1da177e4 LT |
1101 | if (unlikely(details) && page) { |
1102 | /* | |
1103 | * unmap_shared_mapping_pages() wants to | |
1104 | * invalidate cache without truncating: | |
1105 | * unmap shared but keep private pages. | |
1106 | */ | |
1107 | if (details->check_mapping && | |
1108 | details->check_mapping != page->mapping) | |
1109 | continue; | |
1da177e4 | 1110 | } |
b5810039 | 1111 | ptent = ptep_get_and_clear_full(mm, addr, pte, |
a600388d | 1112 | tlb->fullmm); |
1da177e4 LT |
1113 | tlb_remove_tlb_entry(tlb, pte, addr); |
1114 | if (unlikely(!page)) | |
1115 | continue; | |
1da177e4 | 1116 | if (PageAnon(page)) |
d559db08 | 1117 | rss[MM_ANONPAGES]--; |
6237bcd9 | 1118 | else { |
1cf35d47 LT |
1119 | if (pte_dirty(ptent)) { |
1120 | force_flush = 1; | |
6237bcd9 | 1121 | set_page_dirty(page); |
1cf35d47 | 1122 | } |
4917e5d0 | 1123 | if (pte_young(ptent) && |
64363aad | 1124 | likely(!(vma->vm_flags & VM_SEQ_READ))) |
bf3f3bc5 | 1125 | mark_page_accessed(page); |
d559db08 | 1126 | rss[MM_FILEPAGES]--; |
6237bcd9 | 1127 | } |
edc315fd | 1128 | page_remove_rmap(page); |
3dc14741 HD |
1129 | if (unlikely(page_mapcount(page) < 0)) |
1130 | print_bad_pte(vma, addr, ptent, page); | |
1cf35d47 LT |
1131 | if (unlikely(!__tlb_remove_page(tlb, page))) { |
1132 | force_flush = 1; | |
ce9ec37b | 1133 | addr += PAGE_SIZE; |
d16dfc55 | 1134 | break; |
1cf35d47 | 1135 | } |
1da177e4 LT |
1136 | continue; |
1137 | } | |
8a5f14a2 | 1138 | /* If details->check_mapping, we leave swap entries. */ |
1da177e4 LT |
1139 | if (unlikely(details)) |
1140 | continue; | |
b084d435 | 1141 | |
8a5f14a2 KS |
1142 | entry = pte_to_swp_entry(ptent); |
1143 | if (!non_swap_entry(entry)) | |
1144 | rss[MM_SWAPENTS]--; | |
1145 | else if (is_migration_entry(entry)) { | |
1146 | struct page *page; | |
9f9f1acd | 1147 | |
8a5f14a2 | 1148 | page = migration_entry_to_page(entry); |
9f9f1acd | 1149 | |
8a5f14a2 KS |
1150 | if (PageAnon(page)) |
1151 | rss[MM_ANONPAGES]--; | |
1152 | else | |
1153 | rss[MM_FILEPAGES]--; | |
b084d435 | 1154 | } |
8a5f14a2 KS |
1155 | if (unlikely(!free_swap_and_cache(entry))) |
1156 | print_bad_pte(vma, addr, ptent, NULL); | |
9888a1ca | 1157 | pte_clear_not_present_full(mm, addr, pte, tlb->fullmm); |
97a89413 | 1158 | } while (pte++, addr += PAGE_SIZE, addr != end); |
ae859762 | 1159 | |
d559db08 | 1160 | add_mm_rss_vec(mm, rss); |
6606c3e0 | 1161 | arch_leave_lazy_mmu_mode(); |
51c6f666 | 1162 | |
1cf35d47 | 1163 | /* Do the actual TLB flush before dropping ptl */ |
fb7332a9 | 1164 | if (force_flush) |
1cf35d47 | 1165 | tlb_flush_mmu_tlbonly(tlb); |
1cf35d47 LT |
1166 | pte_unmap_unlock(start_pte, ptl); |
1167 | ||
1168 | /* | |
1169 | * If we forced a TLB flush (either due to running out of | |
1170 | * batch buffers or because we needed to flush dirty TLB | |
1171 | * entries before releasing the ptl), free the batched | |
1172 | * memory too. Restart if we didn't do everything. | |
1173 | */ | |
1174 | if (force_flush) { | |
1175 | force_flush = 0; | |
1176 | tlb_flush_mmu_free(tlb); | |
2b047252 LT |
1177 | |
1178 | if (addr != end) | |
d16dfc55 PZ |
1179 | goto again; |
1180 | } | |
1181 | ||
51c6f666 | 1182 | return addr; |
1da177e4 LT |
1183 | } |
1184 | ||
51c6f666 | 1185 | static inline unsigned long zap_pmd_range(struct mmu_gather *tlb, |
b5810039 | 1186 | struct vm_area_struct *vma, pud_t *pud, |
1da177e4 | 1187 | unsigned long addr, unsigned long end, |
97a89413 | 1188 | struct zap_details *details) |
1da177e4 LT |
1189 | { |
1190 | pmd_t *pmd; | |
1191 | unsigned long next; | |
1192 | ||
1193 | pmd = pmd_offset(pud, addr); | |
1194 | do { | |
1195 | next = pmd_addr_end(addr, end); | |
71e3aac0 | 1196 | if (pmd_trans_huge(*pmd)) { |
1a5a9906 | 1197 | if (next - addr != HPAGE_PMD_SIZE) { |
e0897d75 DR |
1198 | #ifdef CONFIG_DEBUG_VM |
1199 | if (!rwsem_is_locked(&tlb->mm->mmap_sem)) { | |
1200 | pr_err("%s: mmap_sem is unlocked! addr=0x%lx end=0x%lx vma->vm_start=0x%lx vma->vm_end=0x%lx\n", | |
1201 | __func__, addr, end, | |
1202 | vma->vm_start, | |
1203 | vma->vm_end); | |
1204 | BUG(); | |
1205 | } | |
1206 | #endif | |
e180377f | 1207 | split_huge_page_pmd(vma, addr, pmd); |
f21760b1 | 1208 | } else if (zap_huge_pmd(tlb, vma, pmd, addr)) |
1a5a9906 | 1209 | goto next; |
71e3aac0 AA |
1210 | /* fall through */ |
1211 | } | |
1a5a9906 AA |
1212 | /* |
1213 | * Here there can be other concurrent MADV_DONTNEED or | |
1214 | * trans huge page faults running, and if the pmd is | |
1215 | * none or trans huge it can change under us. This is | |
1216 | * because MADV_DONTNEED holds the mmap_sem in read | |
1217 | * mode. | |
1218 | */ | |
1219 | if (pmd_none_or_trans_huge_or_clear_bad(pmd)) | |
1220 | goto next; | |
97a89413 | 1221 | next = zap_pte_range(tlb, vma, pmd, addr, next, details); |
1a5a9906 | 1222 | next: |
97a89413 PZ |
1223 | cond_resched(); |
1224 | } while (pmd++, addr = next, addr != end); | |
51c6f666 RH |
1225 | |
1226 | return addr; | |
1da177e4 LT |
1227 | } |
1228 | ||
51c6f666 | 1229 | static inline unsigned long zap_pud_range(struct mmu_gather *tlb, |
b5810039 | 1230 | struct vm_area_struct *vma, pgd_t *pgd, |
1da177e4 | 1231 | unsigned long addr, unsigned long end, |
97a89413 | 1232 | struct zap_details *details) |
1da177e4 LT |
1233 | { |
1234 | pud_t *pud; | |
1235 | unsigned long next; | |
1236 | ||
1237 | pud = pud_offset(pgd, addr); | |
1238 | do { | |
1239 | next = pud_addr_end(addr, end); | |
97a89413 | 1240 | if (pud_none_or_clear_bad(pud)) |
1da177e4 | 1241 | continue; |
97a89413 PZ |
1242 | next = zap_pmd_range(tlb, vma, pud, addr, next, details); |
1243 | } while (pud++, addr = next, addr != end); | |
51c6f666 RH |
1244 | |
1245 | return addr; | |
1da177e4 LT |
1246 | } |
1247 | ||
038c7aa1 AV |
1248 | static void unmap_page_range(struct mmu_gather *tlb, |
1249 | struct vm_area_struct *vma, | |
1250 | unsigned long addr, unsigned long end, | |
1251 | struct zap_details *details) | |
1da177e4 LT |
1252 | { |
1253 | pgd_t *pgd; | |
1254 | unsigned long next; | |
1255 | ||
8a5f14a2 | 1256 | if (details && !details->check_mapping) |
1da177e4 LT |
1257 | details = NULL; |
1258 | ||
1259 | BUG_ON(addr >= end); | |
1260 | tlb_start_vma(tlb, vma); | |
1261 | pgd = pgd_offset(vma->vm_mm, addr); | |
1262 | do { | |
1263 | next = pgd_addr_end(addr, end); | |
97a89413 | 1264 | if (pgd_none_or_clear_bad(pgd)) |
1da177e4 | 1265 | continue; |
97a89413 PZ |
1266 | next = zap_pud_range(tlb, vma, pgd, addr, next, details); |
1267 | } while (pgd++, addr = next, addr != end); | |
1da177e4 LT |
1268 | tlb_end_vma(tlb, vma); |
1269 | } | |
51c6f666 | 1270 | |
f5cc4eef AV |
1271 | |
1272 | static void unmap_single_vma(struct mmu_gather *tlb, | |
1273 | struct vm_area_struct *vma, unsigned long start_addr, | |
4f74d2c8 | 1274 | unsigned long end_addr, |
f5cc4eef AV |
1275 | struct zap_details *details) |
1276 | { | |
1277 | unsigned long start = max(vma->vm_start, start_addr); | |
1278 | unsigned long end; | |
1279 | ||
1280 | if (start >= vma->vm_end) | |
1281 | return; | |
1282 | end = min(vma->vm_end, end_addr); | |
1283 | if (end <= vma->vm_start) | |
1284 | return; | |
1285 | ||
cbc91f71 SD |
1286 | if (vma->vm_file) |
1287 | uprobe_munmap(vma, start, end); | |
1288 | ||
b3b9c293 | 1289 | if (unlikely(vma->vm_flags & VM_PFNMAP)) |
5180da41 | 1290 | untrack_pfn(vma, 0, 0); |
f5cc4eef AV |
1291 | |
1292 | if (start != end) { | |
1293 | if (unlikely(is_vm_hugetlb_page(vma))) { | |
1294 | /* | |
1295 | * It is undesirable to test vma->vm_file as it | |
1296 | * should be non-null for valid hugetlb area. | |
1297 | * However, vm_file will be NULL in the error | |
7aa6b4ad | 1298 | * cleanup path of mmap_region. When |
f5cc4eef | 1299 | * hugetlbfs ->mmap method fails, |
7aa6b4ad | 1300 | * mmap_region() nullifies vma->vm_file |
f5cc4eef AV |
1301 | * before calling this function to clean up. |
1302 | * Since no pte has actually been setup, it is | |
1303 | * safe to do nothing in this case. | |
1304 | */ | |
24669e58 | 1305 | if (vma->vm_file) { |
83cde9e8 | 1306 | i_mmap_lock_write(vma->vm_file->f_mapping); |
d833352a | 1307 | __unmap_hugepage_range_final(tlb, vma, start, end, NULL); |
83cde9e8 | 1308 | i_mmap_unlock_write(vma->vm_file->f_mapping); |
24669e58 | 1309 | } |
f5cc4eef AV |
1310 | } else |
1311 | unmap_page_range(tlb, vma, start, end, details); | |
1312 | } | |
1da177e4 LT |
1313 | } |
1314 | ||
1da177e4 LT |
1315 | /** |
1316 | * unmap_vmas - unmap a range of memory covered by a list of vma's | |
0164f69d | 1317 | * @tlb: address of the caller's struct mmu_gather |
1da177e4 LT |
1318 | * @vma: the starting vma |
1319 | * @start_addr: virtual address at which to start unmapping | |
1320 | * @end_addr: virtual address at which to end unmapping | |
1da177e4 | 1321 | * |
508034a3 | 1322 | * Unmap all pages in the vma list. |
1da177e4 | 1323 | * |
1da177e4 LT |
1324 | * Only addresses between `start' and `end' will be unmapped. |
1325 | * | |
1326 | * The VMA list must be sorted in ascending virtual address order. | |
1327 | * | |
1328 | * unmap_vmas() assumes that the caller will flush the whole unmapped address | |
1329 | * range after unmap_vmas() returns. So the only responsibility here is to | |
1330 | * ensure that any thus-far unmapped pages are flushed before unmap_vmas() | |
1331 | * drops the lock and schedules. | |
1332 | */ | |
6e8bb019 | 1333 | void unmap_vmas(struct mmu_gather *tlb, |
1da177e4 | 1334 | struct vm_area_struct *vma, unsigned long start_addr, |
4f74d2c8 | 1335 | unsigned long end_addr) |
1da177e4 | 1336 | { |
cddb8a5c | 1337 | struct mm_struct *mm = vma->vm_mm; |
1da177e4 | 1338 | |
cddb8a5c | 1339 | mmu_notifier_invalidate_range_start(mm, start_addr, end_addr); |
f5cc4eef | 1340 | for ( ; vma && vma->vm_start < end_addr; vma = vma->vm_next) |
4f74d2c8 | 1341 | unmap_single_vma(tlb, vma, start_addr, end_addr, NULL); |
cddb8a5c | 1342 | mmu_notifier_invalidate_range_end(mm, start_addr, end_addr); |
1da177e4 LT |
1343 | } |
1344 | ||
1345 | /** | |
1346 | * zap_page_range - remove user pages in a given range | |
1347 | * @vma: vm_area_struct holding the applicable pages | |
eb4546bb | 1348 | * @start: starting address of pages to zap |
1da177e4 | 1349 | * @size: number of bytes to zap |
8a5f14a2 | 1350 | * @details: details of shared cache invalidation |
f5cc4eef AV |
1351 | * |
1352 | * Caller must protect the VMA list | |
1da177e4 | 1353 | */ |
7e027b14 | 1354 | void zap_page_range(struct vm_area_struct *vma, unsigned long start, |
1da177e4 LT |
1355 | unsigned long size, struct zap_details *details) |
1356 | { | |
1357 | struct mm_struct *mm = vma->vm_mm; | |
d16dfc55 | 1358 | struct mmu_gather tlb; |
7e027b14 | 1359 | unsigned long end = start + size; |
1da177e4 | 1360 | |
1da177e4 | 1361 | lru_add_drain(); |
2b047252 | 1362 | tlb_gather_mmu(&tlb, mm, start, end); |
365e9c87 | 1363 | update_hiwater_rss(mm); |
7e027b14 LT |
1364 | mmu_notifier_invalidate_range_start(mm, start, end); |
1365 | for ( ; vma && vma->vm_start < end; vma = vma->vm_next) | |
4f74d2c8 | 1366 | unmap_single_vma(&tlb, vma, start, end, details); |
7e027b14 LT |
1367 | mmu_notifier_invalidate_range_end(mm, start, end); |
1368 | tlb_finish_mmu(&tlb, start, end); | |
1da177e4 LT |
1369 | } |
1370 | ||
f5cc4eef AV |
1371 | /** |
1372 | * zap_page_range_single - remove user pages in a given range | |
1373 | * @vma: vm_area_struct holding the applicable pages | |
1374 | * @address: starting address of pages to zap | |
1375 | * @size: number of bytes to zap | |
8a5f14a2 | 1376 | * @details: details of shared cache invalidation |
f5cc4eef AV |
1377 | * |
1378 | * The range must fit into one VMA. | |
1da177e4 | 1379 | */ |
f5cc4eef | 1380 | static void zap_page_range_single(struct vm_area_struct *vma, unsigned long address, |
1da177e4 LT |
1381 | unsigned long size, struct zap_details *details) |
1382 | { | |
1383 | struct mm_struct *mm = vma->vm_mm; | |
d16dfc55 | 1384 | struct mmu_gather tlb; |
1da177e4 | 1385 | unsigned long end = address + size; |
1da177e4 | 1386 | |
1da177e4 | 1387 | lru_add_drain(); |
2b047252 | 1388 | tlb_gather_mmu(&tlb, mm, address, end); |
365e9c87 | 1389 | update_hiwater_rss(mm); |
f5cc4eef | 1390 | mmu_notifier_invalidate_range_start(mm, address, end); |
4f74d2c8 | 1391 | unmap_single_vma(&tlb, vma, address, end, details); |
f5cc4eef | 1392 | mmu_notifier_invalidate_range_end(mm, address, end); |
d16dfc55 | 1393 | tlb_finish_mmu(&tlb, address, end); |
1da177e4 LT |
1394 | } |
1395 | ||
c627f9cc JS |
1396 | /** |
1397 | * zap_vma_ptes - remove ptes mapping the vma | |
1398 | * @vma: vm_area_struct holding ptes to be zapped | |
1399 | * @address: starting address of pages to zap | |
1400 | * @size: number of bytes to zap | |
1401 | * | |
1402 | * This function only unmaps ptes assigned to VM_PFNMAP vmas. | |
1403 | * | |
1404 | * The entire address range must be fully contained within the vma. | |
1405 | * | |
1406 | * Returns 0 if successful. | |
1407 | */ | |
1408 | int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address, | |
1409 | unsigned long size) | |
1410 | { | |
1411 | if (address < vma->vm_start || address + size > vma->vm_end || | |
1412 | !(vma->vm_flags & VM_PFNMAP)) | |
1413 | return -1; | |
f5cc4eef | 1414 | zap_page_range_single(vma, address, size, NULL); |
c627f9cc JS |
1415 | return 0; |
1416 | } | |
1417 | EXPORT_SYMBOL_GPL(zap_vma_ptes); | |
1418 | ||
25ca1d6c | 1419 | pte_t *__get_locked_pte(struct mm_struct *mm, unsigned long addr, |
920c7a5d | 1420 | spinlock_t **ptl) |
c9cfcddf LT |
1421 | { |
1422 | pgd_t * pgd = pgd_offset(mm, addr); | |
1423 | pud_t * pud = pud_alloc(mm, pgd, addr); | |
1424 | if (pud) { | |
49c91fb0 | 1425 | pmd_t * pmd = pmd_alloc(mm, pud, addr); |
f66055ab AA |
1426 | if (pmd) { |
1427 | VM_BUG_ON(pmd_trans_huge(*pmd)); | |
c9cfcddf | 1428 | return pte_alloc_map_lock(mm, pmd, addr, ptl); |
f66055ab | 1429 | } |
c9cfcddf LT |
1430 | } |
1431 | return NULL; | |
1432 | } | |
1433 | ||
238f58d8 LT |
1434 | /* |
1435 | * This is the old fallback for page remapping. | |
1436 | * | |
1437 | * For historical reasons, it only allows reserved pages. Only | |
1438 | * old drivers should use this, and they needed to mark their | |
1439 | * pages reserved for the old functions anyway. | |
1440 | */ | |
423bad60 NP |
1441 | static int insert_page(struct vm_area_struct *vma, unsigned long addr, |
1442 | struct page *page, pgprot_t prot) | |
238f58d8 | 1443 | { |
423bad60 | 1444 | struct mm_struct *mm = vma->vm_mm; |
238f58d8 | 1445 | int retval; |
c9cfcddf | 1446 | pte_t *pte; |
8a9f3ccd BS |
1447 | spinlock_t *ptl; |
1448 | ||
238f58d8 | 1449 | retval = -EINVAL; |
a145dd41 | 1450 | if (PageAnon(page)) |
5b4e655e | 1451 | goto out; |
238f58d8 LT |
1452 | retval = -ENOMEM; |
1453 | flush_dcache_page(page); | |
c9cfcddf | 1454 | pte = get_locked_pte(mm, addr, &ptl); |
238f58d8 | 1455 | if (!pte) |
5b4e655e | 1456 | goto out; |
238f58d8 LT |
1457 | retval = -EBUSY; |
1458 | if (!pte_none(*pte)) | |
1459 | goto out_unlock; | |
1460 | ||
1461 | /* Ok, finally just insert the thing.. */ | |
1462 | get_page(page); | |
34e55232 | 1463 | inc_mm_counter_fast(mm, MM_FILEPAGES); |
238f58d8 LT |
1464 | page_add_file_rmap(page); |
1465 | set_pte_at(mm, addr, pte, mk_pte(page, prot)); | |
1466 | ||
1467 | retval = 0; | |
8a9f3ccd BS |
1468 | pte_unmap_unlock(pte, ptl); |
1469 | return retval; | |
238f58d8 LT |
1470 | out_unlock: |
1471 | pte_unmap_unlock(pte, ptl); | |
1472 | out: | |
1473 | return retval; | |
1474 | } | |
1475 | ||
bfa5bf6d REB |
1476 | /** |
1477 | * vm_insert_page - insert single page into user vma | |
1478 | * @vma: user vma to map to | |
1479 | * @addr: target user address of this page | |
1480 | * @page: source kernel page | |
1481 | * | |
a145dd41 LT |
1482 | * This allows drivers to insert individual pages they've allocated |
1483 | * into a user vma. | |
1484 | * | |
1485 | * The page has to be a nice clean _individual_ kernel allocation. | |
1486 | * If you allocate a compound page, you need to have marked it as | |
1487 | * such (__GFP_COMP), or manually just split the page up yourself | |
8dfcc9ba | 1488 | * (see split_page()). |
a145dd41 LT |
1489 | * |
1490 | * NOTE! Traditionally this was done with "remap_pfn_range()" which | |
1491 | * took an arbitrary page protection parameter. This doesn't allow | |
1492 | * that. Your vma protection will have to be set up correctly, which | |
1493 | * means that if you want a shared writable mapping, you'd better | |
1494 | * ask for a shared writable mapping! | |
1495 | * | |
1496 | * The page does not need to be reserved. | |
4b6e1e37 KK |
1497 | * |
1498 | * Usually this function is called from f_op->mmap() handler | |
1499 | * under mm->mmap_sem write-lock, so it can change vma->vm_flags. | |
1500 | * Caller must set VM_MIXEDMAP on vma if it wants to call this | |
1501 | * function from other places, for example from page-fault handler. | |
a145dd41 | 1502 | */ |
423bad60 NP |
1503 | int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, |
1504 | struct page *page) | |
a145dd41 LT |
1505 | { |
1506 | if (addr < vma->vm_start || addr >= vma->vm_end) | |
1507 | return -EFAULT; | |
1508 | if (!page_count(page)) | |
1509 | return -EINVAL; | |
4b6e1e37 KK |
1510 | if (!(vma->vm_flags & VM_MIXEDMAP)) { |
1511 | BUG_ON(down_read_trylock(&vma->vm_mm->mmap_sem)); | |
1512 | BUG_ON(vma->vm_flags & VM_PFNMAP); | |
1513 | vma->vm_flags |= VM_MIXEDMAP; | |
1514 | } | |
423bad60 | 1515 | return insert_page(vma, addr, page, vma->vm_page_prot); |
a145dd41 | 1516 | } |
e3c3374f | 1517 | EXPORT_SYMBOL(vm_insert_page); |
a145dd41 | 1518 | |
423bad60 NP |
1519 | static int insert_pfn(struct vm_area_struct *vma, unsigned long addr, |
1520 | unsigned long pfn, pgprot_t prot) | |
1521 | { | |
1522 | struct mm_struct *mm = vma->vm_mm; | |
1523 | int retval; | |
1524 | pte_t *pte, entry; | |
1525 | spinlock_t *ptl; | |
1526 | ||
1527 | retval = -ENOMEM; | |
1528 | pte = get_locked_pte(mm, addr, &ptl); | |
1529 | if (!pte) | |
1530 | goto out; | |
1531 | retval = -EBUSY; | |
1532 | if (!pte_none(*pte)) | |
1533 | goto out_unlock; | |
1534 | ||
1535 | /* Ok, finally just insert the thing.. */ | |
1536 | entry = pte_mkspecial(pfn_pte(pfn, prot)); | |
1537 | set_pte_at(mm, addr, pte, entry); | |
4b3073e1 | 1538 | update_mmu_cache(vma, addr, pte); /* XXX: why not for insert_page? */ |
423bad60 NP |
1539 | |
1540 | retval = 0; | |
1541 | out_unlock: | |
1542 | pte_unmap_unlock(pte, ptl); | |
1543 | out: | |
1544 | return retval; | |
1545 | } | |
1546 | ||
e0dc0d8f NP |
1547 | /** |
1548 | * vm_insert_pfn - insert single pfn into user vma | |
1549 | * @vma: user vma to map to | |
1550 | * @addr: target user address of this page | |
1551 | * @pfn: source kernel pfn | |
1552 | * | |
c462f179 | 1553 | * Similar to vm_insert_page, this allows drivers to insert individual pages |
e0dc0d8f NP |
1554 | * they've allocated into a user vma. Same comments apply. |
1555 | * | |
1556 | * This function should only be called from a vm_ops->fault handler, and | |
1557 | * in that case the handler should return NULL. | |
0d71d10a NP |
1558 | * |
1559 | * vma cannot be a COW mapping. | |
1560 | * | |
1561 | * As this is called only for pages that do not currently exist, we | |
1562 | * do not need to flush old virtual caches or the TLB. | |
e0dc0d8f NP |
1563 | */ |
1564 | int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr, | |
423bad60 | 1565 | unsigned long pfn) |
e0dc0d8f | 1566 | { |
2ab64037 | 1567 | int ret; |
e4b866ed | 1568 | pgprot_t pgprot = vma->vm_page_prot; |
7e675137 NP |
1569 | /* |
1570 | * Technically, architectures with pte_special can avoid all these | |
1571 | * restrictions (same for remap_pfn_range). However we would like | |
1572 | * consistency in testing and feature parity among all, so we should | |
1573 | * try to keep these invariants in place for everybody. | |
1574 | */ | |
b379d790 JH |
1575 | BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))); |
1576 | BUG_ON((vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) == | |
1577 | (VM_PFNMAP|VM_MIXEDMAP)); | |
1578 | BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags)); | |
1579 | BUG_ON((vma->vm_flags & VM_MIXEDMAP) && pfn_valid(pfn)); | |
e0dc0d8f | 1580 | |
423bad60 NP |
1581 | if (addr < vma->vm_start || addr >= vma->vm_end) |
1582 | return -EFAULT; | |
5180da41 | 1583 | if (track_pfn_insert(vma, &pgprot, pfn)) |
2ab64037 | 1584 | return -EINVAL; |
1585 | ||
e4b866ed | 1586 | ret = insert_pfn(vma, addr, pfn, pgprot); |
2ab64037 | 1587 | |
2ab64037 | 1588 | return ret; |
423bad60 NP |
1589 | } |
1590 | EXPORT_SYMBOL(vm_insert_pfn); | |
e0dc0d8f | 1591 | |
423bad60 NP |
1592 | int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr, |
1593 | unsigned long pfn) | |
1594 | { | |
1595 | BUG_ON(!(vma->vm_flags & VM_MIXEDMAP)); | |
e0dc0d8f | 1596 | |
423bad60 NP |
1597 | if (addr < vma->vm_start || addr >= vma->vm_end) |
1598 | return -EFAULT; | |
e0dc0d8f | 1599 | |
423bad60 NP |
1600 | /* |
1601 | * If we don't have pte special, then we have to use the pfn_valid() | |
1602 | * based VM_MIXEDMAP scheme (see vm_normal_page), and thus we *must* | |
1603 | * refcount the page if pfn_valid is true (hence insert_page rather | |
62eede62 HD |
1604 | * than insert_pfn). If a zero_pfn were inserted into a VM_MIXEDMAP |
1605 | * without pte special, it would there be refcounted as a normal page. | |
423bad60 NP |
1606 | */ |
1607 | if (!HAVE_PTE_SPECIAL && pfn_valid(pfn)) { | |
1608 | struct page *page; | |
1609 | ||
1610 | page = pfn_to_page(pfn); | |
1611 | return insert_page(vma, addr, page, vma->vm_page_prot); | |
1612 | } | |
1613 | return insert_pfn(vma, addr, pfn, vma->vm_page_prot); | |
e0dc0d8f | 1614 | } |
423bad60 | 1615 | EXPORT_SYMBOL(vm_insert_mixed); |
e0dc0d8f | 1616 | |
1da177e4 LT |
1617 | /* |
1618 | * maps a range of physical memory into the requested pages. the old | |
1619 | * mappings are removed. any references to nonexistent pages results | |
1620 | * in null mappings (currently treated as "copy-on-access") | |
1621 | */ | |
1622 | static int remap_pte_range(struct mm_struct *mm, pmd_t *pmd, | |
1623 | unsigned long addr, unsigned long end, | |
1624 | unsigned long pfn, pgprot_t prot) | |
1625 | { | |
1626 | pte_t *pte; | |
c74df32c | 1627 | spinlock_t *ptl; |
1da177e4 | 1628 | |
c74df32c | 1629 | pte = pte_alloc_map_lock(mm, pmd, addr, &ptl); |
1da177e4 LT |
1630 | if (!pte) |
1631 | return -ENOMEM; | |
6606c3e0 | 1632 | arch_enter_lazy_mmu_mode(); |
1da177e4 LT |
1633 | do { |
1634 | BUG_ON(!pte_none(*pte)); | |
7e675137 | 1635 | set_pte_at(mm, addr, pte, pte_mkspecial(pfn_pte(pfn, prot))); |
1da177e4 LT |
1636 | pfn++; |
1637 | } while (pte++, addr += PAGE_SIZE, addr != end); | |
6606c3e0 | 1638 | arch_leave_lazy_mmu_mode(); |
c74df32c | 1639 | pte_unmap_unlock(pte - 1, ptl); |
1da177e4 LT |
1640 | return 0; |
1641 | } | |
1642 | ||
1643 | static inline int remap_pmd_range(struct mm_struct *mm, pud_t *pud, | |
1644 | unsigned long addr, unsigned long end, | |
1645 | unsigned long pfn, pgprot_t prot) | |
1646 | { | |
1647 | pmd_t *pmd; | |
1648 | unsigned long next; | |
1649 | ||
1650 | pfn -= addr >> PAGE_SHIFT; | |
1651 | pmd = pmd_alloc(mm, pud, addr); | |
1652 | if (!pmd) | |
1653 | return -ENOMEM; | |
f66055ab | 1654 | VM_BUG_ON(pmd_trans_huge(*pmd)); |
1da177e4 LT |
1655 | do { |
1656 | next = pmd_addr_end(addr, end); | |
1657 | if (remap_pte_range(mm, pmd, addr, next, | |
1658 | pfn + (addr >> PAGE_SHIFT), prot)) | |
1659 | return -ENOMEM; | |
1660 | } while (pmd++, addr = next, addr != end); | |
1661 | return 0; | |
1662 | } | |
1663 | ||
1664 | static inline int remap_pud_range(struct mm_struct *mm, pgd_t *pgd, | |
1665 | unsigned long addr, unsigned long end, | |
1666 | unsigned long pfn, pgprot_t prot) | |
1667 | { | |
1668 | pud_t *pud; | |
1669 | unsigned long next; | |
1670 | ||
1671 | pfn -= addr >> PAGE_SHIFT; | |
1672 | pud = pud_alloc(mm, pgd, addr); | |
1673 | if (!pud) | |
1674 | return -ENOMEM; | |
1675 | do { | |
1676 | next = pud_addr_end(addr, end); | |
1677 | if (remap_pmd_range(mm, pud, addr, next, | |
1678 | pfn + (addr >> PAGE_SHIFT), prot)) | |
1679 | return -ENOMEM; | |
1680 | } while (pud++, addr = next, addr != end); | |
1681 | return 0; | |
1682 | } | |
1683 | ||
bfa5bf6d REB |
1684 | /** |
1685 | * remap_pfn_range - remap kernel memory to userspace | |
1686 | * @vma: user vma to map to | |
1687 | * @addr: target user address to start at | |
1688 | * @pfn: physical address of kernel memory | |
1689 | * @size: size of map area | |
1690 | * @prot: page protection flags for this mapping | |
1691 | * | |
1692 | * Note: this is only safe if the mm semaphore is held when called. | |
1693 | */ | |
1da177e4 LT |
1694 | int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, |
1695 | unsigned long pfn, unsigned long size, pgprot_t prot) | |
1696 | { | |
1697 | pgd_t *pgd; | |
1698 | unsigned long next; | |
2d15cab8 | 1699 | unsigned long end = addr + PAGE_ALIGN(size); |
1da177e4 LT |
1700 | struct mm_struct *mm = vma->vm_mm; |
1701 | int err; | |
1702 | ||
1703 | /* | |
1704 | * Physically remapped pages are special. Tell the | |
1705 | * rest of the world about it: | |
1706 | * VM_IO tells people not to look at these pages | |
1707 | * (accesses can have side effects). | |
6aab341e LT |
1708 | * VM_PFNMAP tells the core MM that the base pages are just |
1709 | * raw PFN mappings, and do not have a "struct page" associated | |
1710 | * with them. | |
314e51b9 KK |
1711 | * VM_DONTEXPAND |
1712 | * Disable vma merging and expanding with mremap(). | |
1713 | * VM_DONTDUMP | |
1714 | * Omit vma from core dump, even when VM_IO turned off. | |
fb155c16 LT |
1715 | * |
1716 | * There's a horrible special case to handle copy-on-write | |
1717 | * behaviour that some programs depend on. We mark the "original" | |
1718 | * un-COW'ed pages by matching them up with "vma->vm_pgoff". | |
b3b9c293 | 1719 | * See vm_normal_page() for details. |
1da177e4 | 1720 | */ |
b3b9c293 KK |
1721 | if (is_cow_mapping(vma->vm_flags)) { |
1722 | if (addr != vma->vm_start || end != vma->vm_end) | |
1723 | return -EINVAL; | |
fb155c16 | 1724 | vma->vm_pgoff = pfn; |
b3b9c293 KK |
1725 | } |
1726 | ||
1727 | err = track_pfn_remap(vma, &prot, pfn, addr, PAGE_ALIGN(size)); | |
1728 | if (err) | |
3c8bb73a | 1729 | return -EINVAL; |
fb155c16 | 1730 | |
314e51b9 | 1731 | vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP; |
1da177e4 LT |
1732 | |
1733 | BUG_ON(addr >= end); | |
1734 | pfn -= addr >> PAGE_SHIFT; | |
1735 | pgd = pgd_offset(mm, addr); | |
1736 | flush_cache_range(vma, addr, end); | |
1da177e4 LT |
1737 | do { |
1738 | next = pgd_addr_end(addr, end); | |
1739 | err = remap_pud_range(mm, pgd, addr, next, | |
1740 | pfn + (addr >> PAGE_SHIFT), prot); | |
1741 | if (err) | |
1742 | break; | |
1743 | } while (pgd++, addr = next, addr != end); | |
2ab64037 | 1744 | |
1745 | if (err) | |
5180da41 | 1746 | untrack_pfn(vma, pfn, PAGE_ALIGN(size)); |
2ab64037 | 1747 | |
1da177e4 LT |
1748 | return err; |
1749 | } | |
1750 | EXPORT_SYMBOL(remap_pfn_range); | |
1751 | ||
b4cbb197 LT |
1752 | /** |
1753 | * vm_iomap_memory - remap memory to userspace | |
1754 | * @vma: user vma to map to | |
1755 | * @start: start of area | |
1756 | * @len: size of area | |
1757 | * | |
1758 | * This is a simplified io_remap_pfn_range() for common driver use. The | |
1759 | * driver just needs to give us the physical memory range to be mapped, | |
1760 | * we'll figure out the rest from the vma information. | |
1761 | * | |
1762 | * NOTE! Some drivers might want to tweak vma->vm_page_prot first to get | |
1763 | * whatever write-combining details or similar. | |
1764 | */ | |
1765 | int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len) | |
1766 | { | |
1767 | unsigned long vm_len, pfn, pages; | |
1768 | ||
1769 | /* Check that the physical memory area passed in looks valid */ | |
1770 | if (start + len < start) | |
1771 | return -EINVAL; | |
1772 | /* | |
1773 | * You *really* shouldn't map things that aren't page-aligned, | |
1774 | * but we've historically allowed it because IO memory might | |
1775 | * just have smaller alignment. | |
1776 | */ | |
1777 | len += start & ~PAGE_MASK; | |
1778 | pfn = start >> PAGE_SHIFT; | |
1779 | pages = (len + ~PAGE_MASK) >> PAGE_SHIFT; | |
1780 | if (pfn + pages < pfn) | |
1781 | return -EINVAL; | |
1782 | ||
1783 | /* We start the mapping 'vm_pgoff' pages into the area */ | |
1784 | if (vma->vm_pgoff > pages) | |
1785 | return -EINVAL; | |
1786 | pfn += vma->vm_pgoff; | |
1787 | pages -= vma->vm_pgoff; | |
1788 | ||
1789 | /* Can we fit all of the mapping? */ | |
1790 | vm_len = vma->vm_end - vma->vm_start; | |
1791 | if (vm_len >> PAGE_SHIFT > pages) | |
1792 | return -EINVAL; | |
1793 | ||
1794 | /* Ok, let it rip */ | |
1795 | return io_remap_pfn_range(vma, vma->vm_start, pfn, vm_len, vma->vm_page_prot); | |
1796 | } | |
1797 | EXPORT_SYMBOL(vm_iomap_memory); | |
1798 | ||
aee16b3c JF |
1799 | static int apply_to_pte_range(struct mm_struct *mm, pmd_t *pmd, |
1800 | unsigned long addr, unsigned long end, | |
1801 | pte_fn_t fn, void *data) | |
1802 | { | |
1803 | pte_t *pte; | |
1804 | int err; | |
2f569afd | 1805 | pgtable_t token; |
94909914 | 1806 | spinlock_t *uninitialized_var(ptl); |
aee16b3c JF |
1807 | |
1808 | pte = (mm == &init_mm) ? | |
1809 | pte_alloc_kernel(pmd, addr) : | |
1810 | pte_alloc_map_lock(mm, pmd, addr, &ptl); | |
1811 | if (!pte) | |
1812 | return -ENOMEM; | |
1813 | ||
1814 | BUG_ON(pmd_huge(*pmd)); | |
1815 | ||
38e0edb1 JF |
1816 | arch_enter_lazy_mmu_mode(); |
1817 | ||
2f569afd | 1818 | token = pmd_pgtable(*pmd); |
aee16b3c JF |
1819 | |
1820 | do { | |
c36987e2 | 1821 | err = fn(pte++, token, addr, data); |
aee16b3c JF |
1822 | if (err) |
1823 | break; | |
c36987e2 | 1824 | } while (addr += PAGE_SIZE, addr != end); |
aee16b3c | 1825 | |
38e0edb1 JF |
1826 | arch_leave_lazy_mmu_mode(); |
1827 | ||
aee16b3c JF |
1828 | if (mm != &init_mm) |
1829 | pte_unmap_unlock(pte-1, ptl); | |
1830 | return err; | |
1831 | } | |
1832 | ||
1833 | static int apply_to_pmd_range(struct mm_struct *mm, pud_t *pud, | |
1834 | unsigned long addr, unsigned long end, | |
1835 | pte_fn_t fn, void *data) | |
1836 | { | |
1837 | pmd_t *pmd; | |
1838 | unsigned long next; | |
1839 | int err; | |
1840 | ||
ceb86879 AK |
1841 | BUG_ON(pud_huge(*pud)); |
1842 | ||
aee16b3c JF |
1843 | pmd = pmd_alloc(mm, pud, addr); |
1844 | if (!pmd) | |
1845 | return -ENOMEM; | |
1846 | do { | |
1847 | next = pmd_addr_end(addr, end); | |
1848 | err = apply_to_pte_range(mm, pmd, addr, next, fn, data); | |
1849 | if (err) | |
1850 | break; | |
1851 | } while (pmd++, addr = next, addr != end); | |
1852 | return err; | |
1853 | } | |
1854 | ||
1855 | static int apply_to_pud_range(struct mm_struct *mm, pgd_t *pgd, | |
1856 | unsigned long addr, unsigned long end, | |
1857 | pte_fn_t fn, void *data) | |
1858 | { | |
1859 | pud_t *pud; | |
1860 | unsigned long next; | |
1861 | int err; | |
1862 | ||
1863 | pud = pud_alloc(mm, pgd, addr); | |
1864 | if (!pud) | |
1865 | return -ENOMEM; | |
1866 | do { | |
1867 | next = pud_addr_end(addr, end); | |
1868 | err = apply_to_pmd_range(mm, pud, addr, next, fn, data); | |
1869 | if (err) | |
1870 | break; | |
1871 | } while (pud++, addr = next, addr != end); | |
1872 | return err; | |
1873 | } | |
1874 | ||
1875 | /* | |
1876 | * Scan a region of virtual memory, filling in page tables as necessary | |
1877 | * and calling a provided function on each leaf page table. | |
1878 | */ | |
1879 | int apply_to_page_range(struct mm_struct *mm, unsigned long addr, | |
1880 | unsigned long size, pte_fn_t fn, void *data) | |
1881 | { | |
1882 | pgd_t *pgd; | |
1883 | unsigned long next; | |
57250a5b | 1884 | unsigned long end = addr + size; |
aee16b3c JF |
1885 | int err; |
1886 | ||
1887 | BUG_ON(addr >= end); | |
1888 | pgd = pgd_offset(mm, addr); | |
1889 | do { | |
1890 | next = pgd_addr_end(addr, end); | |
1891 | err = apply_to_pud_range(mm, pgd, addr, next, fn, data); | |
1892 | if (err) | |
1893 | break; | |
1894 | } while (pgd++, addr = next, addr != end); | |
57250a5b | 1895 | |
aee16b3c JF |
1896 | return err; |
1897 | } | |
1898 | EXPORT_SYMBOL_GPL(apply_to_page_range); | |
1899 | ||
8f4e2101 | 1900 | /* |
9b4bdd2f KS |
1901 | * handle_pte_fault chooses page fault handler according to an entry which was |
1902 | * read non-atomically. Before making any commitment, on those architectures | |
1903 | * or configurations (e.g. i386 with PAE) which might give a mix of unmatched | |
1904 | * parts, do_swap_page must check under lock before unmapping the pte and | |
1905 | * proceeding (but do_wp_page is only called after already making such a check; | |
a335b2e1 | 1906 | * and do_anonymous_page can safely check later on). |
8f4e2101 | 1907 | */ |
4c21e2f2 | 1908 | static inline int pte_unmap_same(struct mm_struct *mm, pmd_t *pmd, |
8f4e2101 HD |
1909 | pte_t *page_table, pte_t orig_pte) |
1910 | { | |
1911 | int same = 1; | |
1912 | #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT) | |
1913 | if (sizeof(pte_t) > sizeof(unsigned long)) { | |
4c21e2f2 HD |
1914 | spinlock_t *ptl = pte_lockptr(mm, pmd); |
1915 | spin_lock(ptl); | |
8f4e2101 | 1916 | same = pte_same(*page_table, orig_pte); |
4c21e2f2 | 1917 | spin_unlock(ptl); |
8f4e2101 HD |
1918 | } |
1919 | #endif | |
1920 | pte_unmap(page_table); | |
1921 | return same; | |
1922 | } | |
1923 | ||
9de455b2 | 1924 | static inline void cow_user_page(struct page *dst, struct page *src, unsigned long va, struct vm_area_struct *vma) |
6aab341e | 1925 | { |
0abdd7a8 DW |
1926 | debug_dma_assert_idle(src); |
1927 | ||
6aab341e LT |
1928 | /* |
1929 | * If the source page was a PFN mapping, we don't have | |
1930 | * a "struct page" for it. We do a best-effort copy by | |
1931 | * just copying from the original user address. If that | |
1932 | * fails, we just zero-fill it. Live with it. | |
1933 | */ | |
1934 | if (unlikely(!src)) { | |
9b04c5fe | 1935 | void *kaddr = kmap_atomic(dst); |
5d2a2dbb LT |
1936 | void __user *uaddr = (void __user *)(va & PAGE_MASK); |
1937 | ||
1938 | /* | |
1939 | * This really shouldn't fail, because the page is there | |
1940 | * in the page tables. But it might just be unreadable, | |
1941 | * in which case we just give up and fill the result with | |
1942 | * zeroes. | |
1943 | */ | |
1944 | if (__copy_from_user_inatomic(kaddr, uaddr, PAGE_SIZE)) | |
3ecb01df | 1945 | clear_page(kaddr); |
9b04c5fe | 1946 | kunmap_atomic(kaddr); |
c4ec7b0d | 1947 | flush_dcache_page(dst); |
0ed361de NP |
1948 | } else |
1949 | copy_user_highpage(dst, src, va, vma); | |
6aab341e LT |
1950 | } |
1951 | ||
fb09a464 KS |
1952 | /* |
1953 | * Notify the address space that the page is about to become writable so that | |
1954 | * it can prohibit this or wait for the page to get into an appropriate state. | |
1955 | * | |
1956 | * We do this without the lock held, so that it can sleep if it needs to. | |
1957 | */ | |
1958 | static int do_page_mkwrite(struct vm_area_struct *vma, struct page *page, | |
1959 | unsigned long address) | |
1960 | { | |
1961 | struct vm_fault vmf; | |
1962 | int ret; | |
1963 | ||
1964 | vmf.virtual_address = (void __user *)(address & PAGE_MASK); | |
1965 | vmf.pgoff = page->index; | |
1966 | vmf.flags = FAULT_FLAG_WRITE|FAULT_FLAG_MKWRITE; | |
1967 | vmf.page = page; | |
2e4cdab0 | 1968 | vmf.cow_page = NULL; |
fb09a464 KS |
1969 | |
1970 | ret = vma->vm_ops->page_mkwrite(vma, &vmf); | |
1971 | if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE))) | |
1972 | return ret; | |
1973 | if (unlikely(!(ret & VM_FAULT_LOCKED))) { | |
1974 | lock_page(page); | |
1975 | if (!page->mapping) { | |
1976 | unlock_page(page); | |
1977 | return 0; /* retry */ | |
1978 | } | |
1979 | ret |= VM_FAULT_LOCKED; | |
1980 | } else | |
1981 | VM_BUG_ON_PAGE(!PageLocked(page), page); | |
1982 | return ret; | |
1983 | } | |
1984 | ||
4e047f89 SR |
1985 | /* |
1986 | * Handle write page faults for pages that can be reused in the current vma | |
1987 | * | |
1988 | * This can happen either due to the mapping being with the VM_SHARED flag, | |
1989 | * or due to us being the last reference standing to the page. In either | |
1990 | * case, all we need to do here is to mark the page as writable and update | |
1991 | * any related book-keeping. | |
1992 | */ | |
1993 | static inline int wp_page_reuse(struct mm_struct *mm, | |
1994 | struct vm_area_struct *vma, unsigned long address, | |
1995 | pte_t *page_table, spinlock_t *ptl, pte_t orig_pte, | |
1996 | struct page *page, int page_mkwrite, | |
1997 | int dirty_shared) | |
1998 | __releases(ptl) | |
1999 | { | |
2000 | pte_t entry; | |
2001 | /* | |
2002 | * Clear the pages cpupid information as the existing | |
2003 | * information potentially belongs to a now completely | |
2004 | * unrelated process. | |
2005 | */ | |
2006 | if (page) | |
2007 | page_cpupid_xchg_last(page, (1 << LAST_CPUPID_SHIFT) - 1); | |
2008 | ||
2009 | flush_cache_page(vma, address, pte_pfn(orig_pte)); | |
2010 | entry = pte_mkyoung(orig_pte); | |
2011 | entry = maybe_mkwrite(pte_mkdirty(entry), vma); | |
2012 | if (ptep_set_access_flags(vma, address, page_table, entry, 1)) | |
2013 | update_mmu_cache(vma, address, page_table); | |
2014 | pte_unmap_unlock(page_table, ptl); | |
2015 | ||
2016 | if (dirty_shared) { | |
2017 | struct address_space *mapping; | |
2018 | int dirtied; | |
2019 | ||
2020 | if (!page_mkwrite) | |
2021 | lock_page(page); | |
2022 | ||
2023 | dirtied = set_page_dirty(page); | |
2024 | VM_BUG_ON_PAGE(PageAnon(page), page); | |
2025 | mapping = page->mapping; | |
2026 | unlock_page(page); | |
2027 | page_cache_release(page); | |
2028 | ||
2029 | if ((dirtied || page_mkwrite) && mapping) { | |
2030 | /* | |
2031 | * Some device drivers do not set page.mapping | |
2032 | * but still dirty their pages | |
2033 | */ | |
2034 | balance_dirty_pages_ratelimited(mapping); | |
2035 | } | |
2036 | ||
2037 | if (!page_mkwrite) | |
2038 | file_update_time(vma->vm_file); | |
2039 | } | |
2040 | ||
2041 | return VM_FAULT_WRITE; | |
2042 | } | |
2043 | ||
2f38ab2c SR |
2044 | /* |
2045 | * Handle the case of a page which we actually need to copy to a new page. | |
2046 | * | |
2047 | * Called with mmap_sem locked and the old page referenced, but | |
2048 | * without the ptl held. | |
2049 | * | |
2050 | * High level logic flow: | |
2051 | * | |
2052 | * - Allocate a page, copy the content of the old page to the new one. | |
2053 | * - Handle book keeping and accounting - cgroups, mmu-notifiers, etc. | |
2054 | * - Take the PTL. If the pte changed, bail out and release the allocated page | |
2055 | * - If the pte is still the way we remember it, update the page table and all | |
2056 | * relevant references. This includes dropping the reference the page-table | |
2057 | * held to the old page, as well as updating the rmap. | |
2058 | * - In any case, unlock the PTL and drop the reference we took to the old page. | |
2059 | */ | |
2060 | static int wp_page_copy(struct mm_struct *mm, struct vm_area_struct *vma, | |
2061 | unsigned long address, pte_t *page_table, pmd_t *pmd, | |
2062 | pte_t orig_pte, struct page *old_page) | |
2063 | { | |
2064 | struct page *new_page = NULL; | |
2065 | spinlock_t *ptl = NULL; | |
2066 | pte_t entry; | |
2067 | int page_copied = 0; | |
2068 | const unsigned long mmun_start = address & PAGE_MASK; /* For mmu_notifiers */ | |
2069 | const unsigned long mmun_end = mmun_start + PAGE_SIZE; /* For mmu_notifiers */ | |
2070 | struct mem_cgroup *memcg; | |
2071 | ||
2072 | if (unlikely(anon_vma_prepare(vma))) | |
2073 | goto oom; | |
2074 | ||
2075 | if (is_zero_pfn(pte_pfn(orig_pte))) { | |
2076 | new_page = alloc_zeroed_user_highpage_movable(vma, address); | |
2077 | if (!new_page) | |
2078 | goto oom; | |
2079 | } else { | |
2080 | new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address); | |
2081 | if (!new_page) | |
2082 | goto oom; | |
2083 | cow_user_page(new_page, old_page, address, vma); | |
2084 | } | |
2f38ab2c SR |
2085 | |
2086 | if (mem_cgroup_try_charge(new_page, mm, GFP_KERNEL, &memcg)) | |
2087 | goto oom_free_new; | |
2088 | ||
eb3c24f3 MG |
2089 | __SetPageUptodate(new_page); |
2090 | ||
2f38ab2c SR |
2091 | mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end); |
2092 | ||
2093 | /* | |
2094 | * Re-check the pte - we dropped the lock | |
2095 | */ | |
2096 | page_table = pte_offset_map_lock(mm, pmd, address, &ptl); | |
2097 | if (likely(pte_same(*page_table, orig_pte))) { | |
2098 | if (old_page) { | |
2099 | if (!PageAnon(old_page)) { | |
2100 | dec_mm_counter_fast(mm, MM_FILEPAGES); | |
2101 | inc_mm_counter_fast(mm, MM_ANONPAGES); | |
2102 | } | |
2103 | } else { | |
2104 | inc_mm_counter_fast(mm, MM_ANONPAGES); | |
2105 | } | |
2106 | flush_cache_page(vma, address, pte_pfn(orig_pte)); | |
2107 | entry = mk_pte(new_page, vma->vm_page_prot); | |
2108 | entry = maybe_mkwrite(pte_mkdirty(entry), vma); | |
2109 | /* | |
2110 | * Clear the pte entry and flush it first, before updating the | |
2111 | * pte with the new entry. This will avoid a race condition | |
2112 | * seen in the presence of one thread doing SMC and another | |
2113 | * thread doing COW. | |
2114 | */ | |
2115 | ptep_clear_flush_notify(vma, address, page_table); | |
2116 | page_add_new_anon_rmap(new_page, vma, address); | |
2117 | mem_cgroup_commit_charge(new_page, memcg, false); | |
2118 | lru_cache_add_active_or_unevictable(new_page, vma); | |
2119 | /* | |
2120 | * We call the notify macro here because, when using secondary | |
2121 | * mmu page tables (such as kvm shadow page tables), we want the | |
2122 | * new page to be mapped directly into the secondary page table. | |
2123 | */ | |
2124 | set_pte_at_notify(mm, address, page_table, entry); | |
2125 | update_mmu_cache(vma, address, page_table); | |
2126 | if (old_page) { | |
2127 | /* | |
2128 | * Only after switching the pte to the new page may | |
2129 | * we remove the mapcount here. Otherwise another | |
2130 | * process may come and find the rmap count decremented | |
2131 | * before the pte is switched to the new page, and | |
2132 | * "reuse" the old page writing into it while our pte | |
2133 | * here still points into it and can be read by other | |
2134 | * threads. | |
2135 | * | |
2136 | * The critical issue is to order this | |
2137 | * page_remove_rmap with the ptp_clear_flush above. | |
2138 | * Those stores are ordered by (if nothing else,) | |
2139 | * the barrier present in the atomic_add_negative | |
2140 | * in page_remove_rmap. | |
2141 | * | |
2142 | * Then the TLB flush in ptep_clear_flush ensures that | |
2143 | * no process can access the old page before the | |
2144 | * decremented mapcount is visible. And the old page | |
2145 | * cannot be reused until after the decremented | |
2146 | * mapcount is visible. So transitively, TLBs to | |
2147 | * old page will be flushed before it can be reused. | |
2148 | */ | |
2149 | page_remove_rmap(old_page); | |
2150 | } | |
2151 | ||
2152 | /* Free the old page.. */ | |
2153 | new_page = old_page; | |
2154 | page_copied = 1; | |
2155 | } else { | |
2156 | mem_cgroup_cancel_charge(new_page, memcg); | |
2157 | } | |
2158 | ||
2159 | if (new_page) | |
2160 | page_cache_release(new_page); | |
2161 | ||
2162 | pte_unmap_unlock(page_table, ptl); | |
2163 | mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end); | |
2164 | if (old_page) { | |
2165 | /* | |
2166 | * Don't let another task, with possibly unlocked vma, | |
2167 | * keep the mlocked page. | |
2168 | */ | |
2169 | if (page_copied && (vma->vm_flags & VM_LOCKED)) { | |
2170 | lock_page(old_page); /* LRU manipulation */ | |
2171 | munlock_vma_page(old_page); | |
2172 | unlock_page(old_page); | |
2173 | } | |
2174 | page_cache_release(old_page); | |
2175 | } | |
2176 | return page_copied ? VM_FAULT_WRITE : 0; | |
2177 | oom_free_new: | |
2178 | page_cache_release(new_page); | |
2179 | oom: | |
2180 | if (old_page) | |
2181 | page_cache_release(old_page); | |
2182 | return VM_FAULT_OOM; | |
2183 | } | |
2184 | ||
dd906184 BH |
2185 | /* |
2186 | * Handle write page faults for VM_MIXEDMAP or VM_PFNMAP for a VM_SHARED | |
2187 | * mapping | |
2188 | */ | |
2189 | static int wp_pfn_shared(struct mm_struct *mm, | |
2190 | struct vm_area_struct *vma, unsigned long address, | |
2191 | pte_t *page_table, spinlock_t *ptl, pte_t orig_pte, | |
2192 | pmd_t *pmd) | |
2193 | { | |
2194 | if (vma->vm_ops && vma->vm_ops->pfn_mkwrite) { | |
2195 | struct vm_fault vmf = { | |
2196 | .page = NULL, | |
2197 | .pgoff = linear_page_index(vma, address), | |
2198 | .virtual_address = (void __user *)(address & PAGE_MASK), | |
2199 | .flags = FAULT_FLAG_WRITE | FAULT_FLAG_MKWRITE, | |
2200 | }; | |
2201 | int ret; | |
2202 | ||
2203 | pte_unmap_unlock(page_table, ptl); | |
2204 | ret = vma->vm_ops->pfn_mkwrite(vma, &vmf); | |
2205 | if (ret & VM_FAULT_ERROR) | |
2206 | return ret; | |
2207 | page_table = pte_offset_map_lock(mm, pmd, address, &ptl); | |
2208 | /* | |
2209 | * We might have raced with another page fault while we | |
2210 | * released the pte_offset_map_lock. | |
2211 | */ | |
2212 | if (!pte_same(*page_table, orig_pte)) { | |
2213 | pte_unmap_unlock(page_table, ptl); | |
2214 | return 0; | |
2215 | } | |
2216 | } | |
2217 | return wp_page_reuse(mm, vma, address, page_table, ptl, orig_pte, | |
2218 | NULL, 0, 0); | |
2219 | } | |
2220 | ||
93e478d4 SR |
2221 | static int wp_page_shared(struct mm_struct *mm, struct vm_area_struct *vma, |
2222 | unsigned long address, pte_t *page_table, | |
2223 | pmd_t *pmd, spinlock_t *ptl, pte_t orig_pte, | |
2224 | struct page *old_page) | |
2225 | __releases(ptl) | |
2226 | { | |
2227 | int page_mkwrite = 0; | |
2228 | ||
2229 | page_cache_get(old_page); | |
2230 | ||
2231 | /* | |
2232 | * Only catch write-faults on shared writable pages, | |
2233 | * read-only shared pages can get COWed by | |
2234 | * get_user_pages(.write=1, .force=1). | |
2235 | */ | |
2236 | if (vma->vm_ops && vma->vm_ops->page_mkwrite) { | |
2237 | int tmp; | |
2238 | ||
2239 | pte_unmap_unlock(page_table, ptl); | |
2240 | tmp = do_page_mkwrite(vma, old_page, address); | |
2241 | if (unlikely(!tmp || (tmp & | |
2242 | (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))) { | |
2243 | page_cache_release(old_page); | |
2244 | return tmp; | |
2245 | } | |
2246 | /* | |
2247 | * Since we dropped the lock we need to revalidate | |
2248 | * the PTE as someone else may have changed it. If | |
2249 | * they did, we just return, as we can count on the | |
2250 | * MMU to tell us if they didn't also make it writable. | |
2251 | */ | |
2252 | page_table = pte_offset_map_lock(mm, pmd, address, | |
2253 | &ptl); | |
2254 | if (!pte_same(*page_table, orig_pte)) { | |
2255 | unlock_page(old_page); | |
2256 | pte_unmap_unlock(page_table, ptl); | |
2257 | page_cache_release(old_page); | |
2258 | return 0; | |
2259 | } | |
2260 | page_mkwrite = 1; | |
2261 | } | |
2262 | ||
2263 | return wp_page_reuse(mm, vma, address, page_table, ptl, | |
2264 | orig_pte, old_page, page_mkwrite, 1); | |
2265 | } | |
2266 | ||
1da177e4 LT |
2267 | /* |
2268 | * This routine handles present pages, when users try to write | |
2269 | * to a shared page. It is done by copying the page to a new address | |
2270 | * and decrementing the shared-page counter for the old page. | |
2271 | * | |
1da177e4 LT |
2272 | * Note that this routine assumes that the protection checks have been |
2273 | * done by the caller (the low-level page fault routine in most cases). | |
2274 | * Thus we can safely just mark it writable once we've done any necessary | |
2275 | * COW. | |
2276 | * | |
2277 | * We also mark the page dirty at this point even though the page will | |
2278 | * change only once the write actually happens. This avoids a few races, | |
2279 | * and potentially makes it more efficient. | |
2280 | * | |
8f4e2101 HD |
2281 | * We enter with non-exclusive mmap_sem (to exclude vma changes, |
2282 | * but allow concurrent faults), with pte both mapped and locked. | |
2283 | * We return with mmap_sem still held, but pte unmapped and unlocked. | |
1da177e4 | 2284 | */ |
65500d23 HD |
2285 | static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, |
2286 | unsigned long address, pte_t *page_table, pmd_t *pmd, | |
8f4e2101 | 2287 | spinlock_t *ptl, pte_t orig_pte) |
e6219ec8 | 2288 | __releases(ptl) |
1da177e4 | 2289 | { |
2f38ab2c | 2290 | struct page *old_page; |
1da177e4 | 2291 | |
6aab341e | 2292 | old_page = vm_normal_page(vma, address, orig_pte); |
251b97f5 PZ |
2293 | if (!old_page) { |
2294 | /* | |
64e45507 PF |
2295 | * VM_MIXEDMAP !pfn_valid() case, or VM_SOFTDIRTY clear on a |
2296 | * VM_PFNMAP VMA. | |
251b97f5 PZ |
2297 | * |
2298 | * We should not cow pages in a shared writeable mapping. | |
dd906184 | 2299 | * Just mark the pages writable and/or call ops->pfn_mkwrite. |
251b97f5 PZ |
2300 | */ |
2301 | if ((vma->vm_flags & (VM_WRITE|VM_SHARED)) == | |
2302 | (VM_WRITE|VM_SHARED)) | |
dd906184 BH |
2303 | return wp_pfn_shared(mm, vma, address, page_table, ptl, |
2304 | orig_pte, pmd); | |
2f38ab2c SR |
2305 | |
2306 | pte_unmap_unlock(page_table, ptl); | |
2307 | return wp_page_copy(mm, vma, address, page_table, pmd, | |
2308 | orig_pte, old_page); | |
251b97f5 | 2309 | } |
1da177e4 | 2310 | |
d08b3851 | 2311 | /* |
ee6a6457 PZ |
2312 | * Take out anonymous pages first, anonymous shared vmas are |
2313 | * not dirty accountable. | |
d08b3851 | 2314 | */ |
9a840895 | 2315 | if (PageAnon(old_page) && !PageKsm(old_page)) { |
ab967d86 HD |
2316 | if (!trylock_page(old_page)) { |
2317 | page_cache_get(old_page); | |
2318 | pte_unmap_unlock(page_table, ptl); | |
2319 | lock_page(old_page); | |
2320 | page_table = pte_offset_map_lock(mm, pmd, address, | |
2321 | &ptl); | |
2322 | if (!pte_same(*page_table, orig_pte)) { | |
2323 | unlock_page(old_page); | |
28766805 SR |
2324 | pte_unmap_unlock(page_table, ptl); |
2325 | page_cache_release(old_page); | |
2326 | return 0; | |
ab967d86 HD |
2327 | } |
2328 | page_cache_release(old_page); | |
ee6a6457 | 2329 | } |
b009c024 | 2330 | if (reuse_swap_page(old_page)) { |
c44b6743 RR |
2331 | /* |
2332 | * The page is all ours. Move it to our anon_vma so | |
2333 | * the rmap code will not search our parent or siblings. | |
2334 | * Protected against the rmap code by the page lock. | |
2335 | */ | |
2336 | page_move_anon_rmap(old_page, vma, address); | |
b009c024 | 2337 | unlock_page(old_page); |
4e047f89 SR |
2338 | return wp_page_reuse(mm, vma, address, page_table, ptl, |
2339 | orig_pte, old_page, 0, 0); | |
b009c024 | 2340 | } |
ab967d86 | 2341 | unlock_page(old_page); |
ee6a6457 | 2342 | } else if (unlikely((vma->vm_flags & (VM_WRITE|VM_SHARED)) == |
d08b3851 | 2343 | (VM_WRITE|VM_SHARED))) { |
93e478d4 SR |
2344 | return wp_page_shared(mm, vma, address, page_table, pmd, |
2345 | ptl, orig_pte, old_page); | |
1da177e4 | 2346 | } |
1da177e4 LT |
2347 | |
2348 | /* | |
2349 | * Ok, we need to copy. Oh, well.. | |
2350 | */ | |
b5810039 | 2351 | page_cache_get(old_page); |
28766805 | 2352 | |
8f4e2101 | 2353 | pte_unmap_unlock(page_table, ptl); |
2f38ab2c SR |
2354 | return wp_page_copy(mm, vma, address, page_table, pmd, |
2355 | orig_pte, old_page); | |
1da177e4 LT |
2356 | } |
2357 | ||
97a89413 | 2358 | static void unmap_mapping_range_vma(struct vm_area_struct *vma, |
1da177e4 LT |
2359 | unsigned long start_addr, unsigned long end_addr, |
2360 | struct zap_details *details) | |
2361 | { | |
f5cc4eef | 2362 | zap_page_range_single(vma, start_addr, end_addr - start_addr, details); |
1da177e4 LT |
2363 | } |
2364 | ||
6b2dbba8 | 2365 | static inline void unmap_mapping_range_tree(struct rb_root *root, |
1da177e4 LT |
2366 | struct zap_details *details) |
2367 | { | |
2368 | struct vm_area_struct *vma; | |
1da177e4 LT |
2369 | pgoff_t vba, vea, zba, zea; |
2370 | ||
6b2dbba8 | 2371 | vma_interval_tree_foreach(vma, root, |
1da177e4 | 2372 | details->first_index, details->last_index) { |
1da177e4 LT |
2373 | |
2374 | vba = vma->vm_pgoff; | |
d6e93217 | 2375 | vea = vba + vma_pages(vma) - 1; |
1da177e4 LT |
2376 | /* Assume for now that PAGE_CACHE_SHIFT == PAGE_SHIFT */ |
2377 | zba = details->first_index; | |
2378 | if (zba < vba) | |
2379 | zba = vba; | |
2380 | zea = details->last_index; | |
2381 | if (zea > vea) | |
2382 | zea = vea; | |
2383 | ||
97a89413 | 2384 | unmap_mapping_range_vma(vma, |
1da177e4 LT |
2385 | ((zba - vba) << PAGE_SHIFT) + vma->vm_start, |
2386 | ((zea - vba + 1) << PAGE_SHIFT) + vma->vm_start, | |
97a89413 | 2387 | details); |
1da177e4 LT |
2388 | } |
2389 | } | |
2390 | ||
1da177e4 | 2391 | /** |
8a5f14a2 KS |
2392 | * unmap_mapping_range - unmap the portion of all mmaps in the specified |
2393 | * address_space corresponding to the specified page range in the underlying | |
2394 | * file. | |
2395 | * | |
3d41088f | 2396 | * @mapping: the address space containing mmaps to be unmapped. |
1da177e4 LT |
2397 | * @holebegin: byte in first page to unmap, relative to the start of |
2398 | * the underlying file. This will be rounded down to a PAGE_SIZE | |
25d9e2d1 | 2399 | * boundary. Note that this is different from truncate_pagecache(), which |
1da177e4 LT |
2400 | * must keep the partial page. In contrast, we must get rid of |
2401 | * partial pages. | |
2402 | * @holelen: size of prospective hole in bytes. This will be rounded | |
2403 | * up to a PAGE_SIZE boundary. A holelen of zero truncates to the | |
2404 | * end of the file. | |
2405 | * @even_cows: 1 when truncating a file, unmap even private COWed pages; | |
2406 | * but 0 when invalidating pagecache, don't throw away private data. | |
2407 | */ | |
2408 | void unmap_mapping_range(struct address_space *mapping, | |
2409 | loff_t const holebegin, loff_t const holelen, int even_cows) | |
2410 | { | |
2411 | struct zap_details details; | |
2412 | pgoff_t hba = holebegin >> PAGE_SHIFT; | |
2413 | pgoff_t hlen = (holelen + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
2414 | ||
2415 | /* Check for overflow. */ | |
2416 | if (sizeof(holelen) > sizeof(hlen)) { | |
2417 | long long holeend = | |
2418 | (holebegin + holelen + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
2419 | if (holeend & ~(long long)ULONG_MAX) | |
2420 | hlen = ULONG_MAX - hba + 1; | |
2421 | } | |
2422 | ||
2423 | details.check_mapping = even_cows? NULL: mapping; | |
1da177e4 LT |
2424 | details.first_index = hba; |
2425 | details.last_index = hba + hlen - 1; | |
2426 | if (details.last_index < details.first_index) | |
2427 | details.last_index = ULONG_MAX; | |
1da177e4 | 2428 | |
1da177e4 | 2429 | |
283307c7 | 2430 | /* DAX uses i_mmap_lock to serialise file truncate vs page fault */ |
48ec833b | 2431 | i_mmap_lock_write(mapping); |
6b2dbba8 | 2432 | if (unlikely(!RB_EMPTY_ROOT(&mapping->i_mmap))) |
1da177e4 | 2433 | unmap_mapping_range_tree(&mapping->i_mmap, &details); |
48ec833b | 2434 | i_mmap_unlock_write(mapping); |
1da177e4 LT |
2435 | } |
2436 | EXPORT_SYMBOL(unmap_mapping_range); | |
2437 | ||
1da177e4 | 2438 | /* |
8f4e2101 HD |
2439 | * We enter with non-exclusive mmap_sem (to exclude vma changes, |
2440 | * but allow concurrent faults), and pte mapped but not yet locked. | |
9a95f3cf PC |
2441 | * We return with pte unmapped and unlocked. |
2442 | * | |
2443 | * We return with the mmap_sem locked or unlocked in the same cases | |
2444 | * as does filemap_fault(). | |
1da177e4 | 2445 | */ |
65500d23 HD |
2446 | static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma, |
2447 | unsigned long address, pte_t *page_table, pmd_t *pmd, | |
30c9f3a9 | 2448 | unsigned int flags, pte_t orig_pte) |
1da177e4 | 2449 | { |
8f4e2101 | 2450 | spinlock_t *ptl; |
56f31801 | 2451 | struct page *page, *swapcache; |
00501b53 | 2452 | struct mem_cgroup *memcg; |
65500d23 | 2453 | swp_entry_t entry; |
1da177e4 | 2454 | pte_t pte; |
d065bd81 | 2455 | int locked; |
ad8c2ee8 | 2456 | int exclusive = 0; |
83c54070 | 2457 | int ret = 0; |
1da177e4 | 2458 | |
4c21e2f2 | 2459 | if (!pte_unmap_same(mm, pmd, page_table, orig_pte)) |
8f4e2101 | 2460 | goto out; |
65500d23 HD |
2461 | |
2462 | entry = pte_to_swp_entry(orig_pte); | |
d1737fdb AK |
2463 | if (unlikely(non_swap_entry(entry))) { |
2464 | if (is_migration_entry(entry)) { | |
2465 | migration_entry_wait(mm, pmd, address); | |
2466 | } else if (is_hwpoison_entry(entry)) { | |
2467 | ret = VM_FAULT_HWPOISON; | |
2468 | } else { | |
2469 | print_bad_pte(vma, address, orig_pte, NULL); | |
d99be1a8 | 2470 | ret = VM_FAULT_SIGBUS; |
d1737fdb | 2471 | } |
0697212a CL |
2472 | goto out; |
2473 | } | |
0ff92245 | 2474 | delayacct_set_flag(DELAYACCT_PF_SWAPIN); |
1da177e4 LT |
2475 | page = lookup_swap_cache(entry); |
2476 | if (!page) { | |
02098fea HD |
2477 | page = swapin_readahead(entry, |
2478 | GFP_HIGHUSER_MOVABLE, vma, address); | |
1da177e4 LT |
2479 | if (!page) { |
2480 | /* | |
8f4e2101 HD |
2481 | * Back out if somebody else faulted in this pte |
2482 | * while we released the pte lock. | |
1da177e4 | 2483 | */ |
8f4e2101 | 2484 | page_table = pte_offset_map_lock(mm, pmd, address, &ptl); |
1da177e4 LT |
2485 | if (likely(pte_same(*page_table, orig_pte))) |
2486 | ret = VM_FAULT_OOM; | |
0ff92245 | 2487 | delayacct_clear_flag(DELAYACCT_PF_SWAPIN); |
65500d23 | 2488 | goto unlock; |
1da177e4 LT |
2489 | } |
2490 | ||
2491 | /* Had to read the page from swap area: Major fault */ | |
2492 | ret = VM_FAULT_MAJOR; | |
f8891e5e | 2493 | count_vm_event(PGMAJFAULT); |
456f998e | 2494 | mem_cgroup_count_vm_event(mm, PGMAJFAULT); |
d1737fdb | 2495 | } else if (PageHWPoison(page)) { |
71f72525 WF |
2496 | /* |
2497 | * hwpoisoned dirty swapcache pages are kept for killing | |
2498 | * owner processes (which may be unknown at hwpoison time) | |
2499 | */ | |
d1737fdb AK |
2500 | ret = VM_FAULT_HWPOISON; |
2501 | delayacct_clear_flag(DELAYACCT_PF_SWAPIN); | |
56f31801 | 2502 | swapcache = page; |
4779cb31 | 2503 | goto out_release; |
1da177e4 LT |
2504 | } |
2505 | ||
56f31801 | 2506 | swapcache = page; |
d065bd81 | 2507 | locked = lock_page_or_retry(page, mm, flags); |
e709ffd6 | 2508 | |
073e587e | 2509 | delayacct_clear_flag(DELAYACCT_PF_SWAPIN); |
d065bd81 ML |
2510 | if (!locked) { |
2511 | ret |= VM_FAULT_RETRY; | |
2512 | goto out_release; | |
2513 | } | |
073e587e | 2514 | |
4969c119 | 2515 | /* |
31c4a3d3 HD |
2516 | * Make sure try_to_free_swap or reuse_swap_page or swapoff did not |
2517 | * release the swapcache from under us. The page pin, and pte_same | |
2518 | * test below, are not enough to exclude that. Even if it is still | |
2519 | * swapcache, we need to check that the page's swap has not changed. | |
4969c119 | 2520 | */ |
31c4a3d3 | 2521 | if (unlikely(!PageSwapCache(page) || page_private(page) != entry.val)) |
4969c119 AA |
2522 | goto out_page; |
2523 | ||
cbf86cfe HD |
2524 | page = ksm_might_need_to_copy(page, vma, address); |
2525 | if (unlikely(!page)) { | |
2526 | ret = VM_FAULT_OOM; | |
2527 | page = swapcache; | |
cbf86cfe | 2528 | goto out_page; |
5ad64688 HD |
2529 | } |
2530 | ||
00501b53 | 2531 | if (mem_cgroup_try_charge(page, mm, GFP_KERNEL, &memcg)) { |
8a9f3ccd | 2532 | ret = VM_FAULT_OOM; |
bc43f75c | 2533 | goto out_page; |
8a9f3ccd BS |
2534 | } |
2535 | ||
1da177e4 | 2536 | /* |
8f4e2101 | 2537 | * Back out if somebody else already faulted in this pte. |
1da177e4 | 2538 | */ |
8f4e2101 | 2539 | page_table = pte_offset_map_lock(mm, pmd, address, &ptl); |
9e9bef07 | 2540 | if (unlikely(!pte_same(*page_table, orig_pte))) |
b8107480 | 2541 | goto out_nomap; |
b8107480 KK |
2542 | |
2543 | if (unlikely(!PageUptodate(page))) { | |
2544 | ret = VM_FAULT_SIGBUS; | |
2545 | goto out_nomap; | |
1da177e4 LT |
2546 | } |
2547 | ||
8c7c6e34 KH |
2548 | /* |
2549 | * The page isn't present yet, go ahead with the fault. | |
2550 | * | |
2551 | * Be careful about the sequence of operations here. | |
2552 | * To get its accounting right, reuse_swap_page() must be called | |
2553 | * while the page is counted on swap but not yet in mapcount i.e. | |
2554 | * before page_add_anon_rmap() and swap_free(); try_to_free_swap() | |
2555 | * must be called after the swap_free(), or it will never succeed. | |
8c7c6e34 | 2556 | */ |
1da177e4 | 2557 | |
34e55232 | 2558 | inc_mm_counter_fast(mm, MM_ANONPAGES); |
b084d435 | 2559 | dec_mm_counter_fast(mm, MM_SWAPENTS); |
1da177e4 | 2560 | pte = mk_pte(page, vma->vm_page_prot); |
30c9f3a9 | 2561 | if ((flags & FAULT_FLAG_WRITE) && reuse_swap_page(page)) { |
1da177e4 | 2562 | pte = maybe_mkwrite(pte_mkdirty(pte), vma); |
30c9f3a9 | 2563 | flags &= ~FAULT_FLAG_WRITE; |
9a5b489b | 2564 | ret |= VM_FAULT_WRITE; |
ad8c2ee8 | 2565 | exclusive = 1; |
1da177e4 | 2566 | } |
1da177e4 | 2567 | flush_icache_page(vma, page); |
179ef71c CG |
2568 | if (pte_swp_soft_dirty(orig_pte)) |
2569 | pte = pte_mksoft_dirty(pte); | |
1da177e4 | 2570 | set_pte_at(mm, address, page_table, pte); |
00501b53 | 2571 | if (page == swapcache) { |
af34770e | 2572 | do_page_add_anon_rmap(page, vma, address, exclusive); |
00501b53 JW |
2573 | mem_cgroup_commit_charge(page, memcg, true); |
2574 | } else { /* ksm created a completely new copy */ | |
56f31801 | 2575 | page_add_new_anon_rmap(page, vma, address); |
00501b53 JW |
2576 | mem_cgroup_commit_charge(page, memcg, false); |
2577 | lru_cache_add_active_or_unevictable(page, vma); | |
2578 | } | |
1da177e4 | 2579 | |
c475a8ab | 2580 | swap_free(entry); |
b291f000 | 2581 | if (vm_swap_full() || (vma->vm_flags & VM_LOCKED) || PageMlocked(page)) |
a2c43eed | 2582 | try_to_free_swap(page); |
c475a8ab | 2583 | unlock_page(page); |
56f31801 | 2584 | if (page != swapcache) { |
4969c119 AA |
2585 | /* |
2586 | * Hold the lock to avoid the swap entry to be reused | |
2587 | * until we take the PT lock for the pte_same() check | |
2588 | * (to avoid false positives from pte_same). For | |
2589 | * further safety release the lock after the swap_free | |
2590 | * so that the swap count won't change under a | |
2591 | * parallel locked swapcache. | |
2592 | */ | |
2593 | unlock_page(swapcache); | |
2594 | page_cache_release(swapcache); | |
2595 | } | |
c475a8ab | 2596 | |
30c9f3a9 | 2597 | if (flags & FAULT_FLAG_WRITE) { |
61469f1d HD |
2598 | ret |= do_wp_page(mm, vma, address, page_table, pmd, ptl, pte); |
2599 | if (ret & VM_FAULT_ERROR) | |
2600 | ret &= VM_FAULT_ERROR; | |
1da177e4 LT |
2601 | goto out; |
2602 | } | |
2603 | ||
2604 | /* No need to invalidate - it was non-present before */ | |
4b3073e1 | 2605 | update_mmu_cache(vma, address, page_table); |
65500d23 | 2606 | unlock: |
8f4e2101 | 2607 | pte_unmap_unlock(page_table, ptl); |
1da177e4 LT |
2608 | out: |
2609 | return ret; | |
b8107480 | 2610 | out_nomap: |
00501b53 | 2611 | mem_cgroup_cancel_charge(page, memcg); |
8f4e2101 | 2612 | pte_unmap_unlock(page_table, ptl); |
bc43f75c | 2613 | out_page: |
b8107480 | 2614 | unlock_page(page); |
4779cb31 | 2615 | out_release: |
b8107480 | 2616 | page_cache_release(page); |
56f31801 | 2617 | if (page != swapcache) { |
4969c119 AA |
2618 | unlock_page(swapcache); |
2619 | page_cache_release(swapcache); | |
2620 | } | |
65500d23 | 2621 | return ret; |
1da177e4 LT |
2622 | } |
2623 | ||
320b2b8d | 2624 | /* |
8ca3eb08 TL |
2625 | * This is like a special single-page "expand_{down|up}wards()", |
2626 | * except we must first make sure that 'address{-|+}PAGE_SIZE' | |
320b2b8d | 2627 | * doesn't hit another vma. |
320b2b8d LT |
2628 | */ |
2629 | static inline int check_stack_guard_page(struct vm_area_struct *vma, unsigned long address) | |
2630 | { | |
2631 | address &= PAGE_MASK; | |
2632 | if ((vma->vm_flags & VM_GROWSDOWN) && address == vma->vm_start) { | |
0e8e50e2 LT |
2633 | struct vm_area_struct *prev = vma->vm_prev; |
2634 | ||
2635 | /* | |
2636 | * Is there a mapping abutting this one below? | |
2637 | * | |
2638 | * That's only ok if it's the same stack mapping | |
2639 | * that has gotten split.. | |
2640 | */ | |
2641 | if (prev && prev->vm_end == address) | |
2642 | return prev->vm_flags & VM_GROWSDOWN ? 0 : -ENOMEM; | |
320b2b8d | 2643 | |
fee7e49d | 2644 | return expand_downwards(vma, address - PAGE_SIZE); |
320b2b8d | 2645 | } |
8ca3eb08 TL |
2646 | if ((vma->vm_flags & VM_GROWSUP) && address + PAGE_SIZE == vma->vm_end) { |
2647 | struct vm_area_struct *next = vma->vm_next; | |
2648 | ||
2649 | /* As VM_GROWSDOWN but s/below/above/ */ | |
2650 | if (next && next->vm_start == address + PAGE_SIZE) | |
2651 | return next->vm_flags & VM_GROWSUP ? 0 : -ENOMEM; | |
2652 | ||
fee7e49d | 2653 | return expand_upwards(vma, address + PAGE_SIZE); |
8ca3eb08 | 2654 | } |
320b2b8d LT |
2655 | return 0; |
2656 | } | |
2657 | ||
1da177e4 | 2658 | /* |
8f4e2101 HD |
2659 | * We enter with non-exclusive mmap_sem (to exclude vma changes, |
2660 | * but allow concurrent faults), and pte mapped but not yet locked. | |
2661 | * We return with mmap_sem still held, but pte unmapped and unlocked. | |
1da177e4 | 2662 | */ |
65500d23 HD |
2663 | static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, |
2664 | unsigned long address, pte_t *page_table, pmd_t *pmd, | |
30c9f3a9 | 2665 | unsigned int flags) |
1da177e4 | 2666 | { |
00501b53 | 2667 | struct mem_cgroup *memcg; |
8f4e2101 HD |
2668 | struct page *page; |
2669 | spinlock_t *ptl; | |
1da177e4 | 2670 | pte_t entry; |
1da177e4 | 2671 | |
11ac5524 LT |
2672 | pte_unmap(page_table); |
2673 | ||
6b7339f4 KS |
2674 | /* File mapping without ->vm_ops ? */ |
2675 | if (vma->vm_flags & VM_SHARED) | |
2676 | return VM_FAULT_SIGBUS; | |
2677 | ||
11ac5524 LT |
2678 | /* Check if we need to add a guard page to the stack */ |
2679 | if (check_stack_guard_page(vma, address) < 0) | |
9c145c56 | 2680 | return VM_FAULT_SIGSEGV; |
320b2b8d | 2681 | |
11ac5524 | 2682 | /* Use the zero-page for reads */ |
593befa6 | 2683 | if (!(flags & FAULT_FLAG_WRITE) && !mm_forbids_zeropage(mm)) { |
62eede62 HD |
2684 | entry = pte_mkspecial(pfn_pte(my_zero_pfn(address), |
2685 | vma->vm_page_prot)); | |
11ac5524 | 2686 | page_table = pte_offset_map_lock(mm, pmd, address, &ptl); |
a13ea5b7 HD |
2687 | if (!pte_none(*page_table)) |
2688 | goto unlock; | |
6b251fc9 AA |
2689 | /* Deliver the page fault to userland, check inside PT lock */ |
2690 | if (userfaultfd_missing(vma)) { | |
2691 | pte_unmap_unlock(page_table, ptl); | |
2692 | return handle_userfault(vma, address, flags, | |
2693 | VM_UFFD_MISSING); | |
2694 | } | |
a13ea5b7 HD |
2695 | goto setpte; |
2696 | } | |
2697 | ||
557ed1fa | 2698 | /* Allocate our own private page. */ |
557ed1fa NP |
2699 | if (unlikely(anon_vma_prepare(vma))) |
2700 | goto oom; | |
2701 | page = alloc_zeroed_user_highpage_movable(vma, address); | |
2702 | if (!page) | |
2703 | goto oom; | |
eb3c24f3 MG |
2704 | |
2705 | if (mem_cgroup_try_charge(page, mm, GFP_KERNEL, &memcg)) | |
2706 | goto oom_free_page; | |
2707 | ||
52f37629 MK |
2708 | /* |
2709 | * The memory barrier inside __SetPageUptodate makes sure that | |
2710 | * preceeding stores to the page contents become visible before | |
2711 | * the set_pte_at() write. | |
2712 | */ | |
0ed361de | 2713 | __SetPageUptodate(page); |
8f4e2101 | 2714 | |
557ed1fa | 2715 | entry = mk_pte(page, vma->vm_page_prot); |
1ac0cb5d HD |
2716 | if (vma->vm_flags & VM_WRITE) |
2717 | entry = pte_mkwrite(pte_mkdirty(entry)); | |
1da177e4 | 2718 | |
557ed1fa | 2719 | page_table = pte_offset_map_lock(mm, pmd, address, &ptl); |
1c2fb7a4 | 2720 | if (!pte_none(*page_table)) |
557ed1fa | 2721 | goto release; |
9ba69294 | 2722 | |
6b251fc9 AA |
2723 | /* Deliver the page fault to userland, check inside PT lock */ |
2724 | if (userfaultfd_missing(vma)) { | |
2725 | pte_unmap_unlock(page_table, ptl); | |
2726 | mem_cgroup_cancel_charge(page, memcg); | |
2727 | page_cache_release(page); | |
2728 | return handle_userfault(vma, address, flags, | |
2729 | VM_UFFD_MISSING); | |
2730 | } | |
2731 | ||
34e55232 | 2732 | inc_mm_counter_fast(mm, MM_ANONPAGES); |
557ed1fa | 2733 | page_add_new_anon_rmap(page, vma, address); |
00501b53 JW |
2734 | mem_cgroup_commit_charge(page, memcg, false); |
2735 | lru_cache_add_active_or_unevictable(page, vma); | |
a13ea5b7 | 2736 | setpte: |
65500d23 | 2737 | set_pte_at(mm, address, page_table, entry); |
1da177e4 LT |
2738 | |
2739 | /* No need to invalidate - it was non-present before */ | |
4b3073e1 | 2740 | update_mmu_cache(vma, address, page_table); |
65500d23 | 2741 | unlock: |
8f4e2101 | 2742 | pte_unmap_unlock(page_table, ptl); |
83c54070 | 2743 | return 0; |
8f4e2101 | 2744 | release: |
00501b53 | 2745 | mem_cgroup_cancel_charge(page, memcg); |
8f4e2101 HD |
2746 | page_cache_release(page); |
2747 | goto unlock; | |
8a9f3ccd | 2748 | oom_free_page: |
6dbf6d3b | 2749 | page_cache_release(page); |
65500d23 | 2750 | oom: |
1da177e4 LT |
2751 | return VM_FAULT_OOM; |
2752 | } | |
2753 | ||
9a95f3cf PC |
2754 | /* |
2755 | * The mmap_sem must have been held on entry, and may have been | |
2756 | * released depending on flags and vma->vm_ops->fault() return value. | |
2757 | * See filemap_fault() and __lock_page_retry(). | |
2758 | */ | |
7eae74af | 2759 | static int __do_fault(struct vm_area_struct *vma, unsigned long address, |
2e4cdab0 MW |
2760 | pgoff_t pgoff, unsigned int flags, |
2761 | struct page *cow_page, struct page **page) | |
7eae74af KS |
2762 | { |
2763 | struct vm_fault vmf; | |
2764 | int ret; | |
2765 | ||
2766 | vmf.virtual_address = (void __user *)(address & PAGE_MASK); | |
2767 | vmf.pgoff = pgoff; | |
2768 | vmf.flags = flags; | |
2769 | vmf.page = NULL; | |
2e4cdab0 | 2770 | vmf.cow_page = cow_page; |
7eae74af KS |
2771 | |
2772 | ret = vma->vm_ops->fault(vma, &vmf); | |
2773 | if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY))) | |
2774 | return ret; | |
2e4cdab0 MW |
2775 | if (!vmf.page) |
2776 | goto out; | |
7eae74af KS |
2777 | |
2778 | if (unlikely(PageHWPoison(vmf.page))) { | |
2779 | if (ret & VM_FAULT_LOCKED) | |
2780 | unlock_page(vmf.page); | |
2781 | page_cache_release(vmf.page); | |
2782 | return VM_FAULT_HWPOISON; | |
2783 | } | |
2784 | ||
2785 | if (unlikely(!(ret & VM_FAULT_LOCKED))) | |
2786 | lock_page(vmf.page); | |
2787 | else | |
2788 | VM_BUG_ON_PAGE(!PageLocked(vmf.page), vmf.page); | |
2789 | ||
2e4cdab0 | 2790 | out: |
7eae74af KS |
2791 | *page = vmf.page; |
2792 | return ret; | |
2793 | } | |
2794 | ||
8c6e50b0 KS |
2795 | /** |
2796 | * do_set_pte - setup new PTE entry for given page and add reverse page mapping. | |
2797 | * | |
2798 | * @vma: virtual memory area | |
2799 | * @address: user virtual address | |
2800 | * @page: page to map | |
2801 | * @pte: pointer to target page table entry | |
2802 | * @write: true, if new entry is writable | |
2803 | * @anon: true, if it's anonymous page | |
2804 | * | |
2805 | * Caller must hold page table lock relevant for @pte. | |
2806 | * | |
2807 | * Target users are page handler itself and implementations of | |
2808 | * vm_ops->map_pages. | |
2809 | */ | |
2810 | void do_set_pte(struct vm_area_struct *vma, unsigned long address, | |
3bb97794 KS |
2811 | struct page *page, pte_t *pte, bool write, bool anon) |
2812 | { | |
2813 | pte_t entry; | |
2814 | ||
2815 | flush_icache_page(vma, page); | |
2816 | entry = mk_pte(page, vma->vm_page_prot); | |
2817 | if (write) | |
2818 | entry = maybe_mkwrite(pte_mkdirty(entry), vma); | |
3bb97794 KS |
2819 | if (anon) { |
2820 | inc_mm_counter_fast(vma->vm_mm, MM_ANONPAGES); | |
2821 | page_add_new_anon_rmap(page, vma, address); | |
2822 | } else { | |
2823 | inc_mm_counter_fast(vma->vm_mm, MM_FILEPAGES); | |
2824 | page_add_file_rmap(page); | |
2825 | } | |
2826 | set_pte_at(vma->vm_mm, address, pte, entry); | |
2827 | ||
2828 | /* no need to invalidate: a not-present page won't be cached */ | |
2829 | update_mmu_cache(vma, address, pte); | |
2830 | } | |
2831 | ||
3a91053a KS |
2832 | static unsigned long fault_around_bytes __read_mostly = |
2833 | rounddown_pow_of_two(65536); | |
a9b0f861 | 2834 | |
a9b0f861 KS |
2835 | #ifdef CONFIG_DEBUG_FS |
2836 | static int fault_around_bytes_get(void *data, u64 *val) | |
1592eef0 | 2837 | { |
a9b0f861 | 2838 | *val = fault_around_bytes; |
1592eef0 KS |
2839 | return 0; |
2840 | } | |
2841 | ||
b4903d6e AR |
2842 | /* |
2843 | * fault_around_pages() and fault_around_mask() expects fault_around_bytes | |
2844 | * rounded down to nearest page order. It's what do_fault_around() expects to | |
2845 | * see. | |
2846 | */ | |
a9b0f861 | 2847 | static int fault_around_bytes_set(void *data, u64 val) |
1592eef0 | 2848 | { |
a9b0f861 | 2849 | if (val / PAGE_SIZE > PTRS_PER_PTE) |
1592eef0 | 2850 | return -EINVAL; |
b4903d6e AR |
2851 | if (val > PAGE_SIZE) |
2852 | fault_around_bytes = rounddown_pow_of_two(val); | |
2853 | else | |
2854 | fault_around_bytes = PAGE_SIZE; /* rounddown_pow_of_two(0) is undefined */ | |
1592eef0 KS |
2855 | return 0; |
2856 | } | |
a9b0f861 KS |
2857 | DEFINE_SIMPLE_ATTRIBUTE(fault_around_bytes_fops, |
2858 | fault_around_bytes_get, fault_around_bytes_set, "%llu\n"); | |
1592eef0 KS |
2859 | |
2860 | static int __init fault_around_debugfs(void) | |
2861 | { | |
2862 | void *ret; | |
2863 | ||
a9b0f861 KS |
2864 | ret = debugfs_create_file("fault_around_bytes", 0644, NULL, NULL, |
2865 | &fault_around_bytes_fops); | |
1592eef0 | 2866 | if (!ret) |
a9b0f861 | 2867 | pr_warn("Failed to create fault_around_bytes in debugfs"); |
1592eef0 KS |
2868 | return 0; |
2869 | } | |
2870 | late_initcall(fault_around_debugfs); | |
1592eef0 | 2871 | #endif |
8c6e50b0 | 2872 | |
1fdb412b KS |
2873 | /* |
2874 | * do_fault_around() tries to map few pages around the fault address. The hope | |
2875 | * is that the pages will be needed soon and this will lower the number of | |
2876 | * faults to handle. | |
2877 | * | |
2878 | * It uses vm_ops->map_pages() to map the pages, which skips the page if it's | |
2879 | * not ready to be mapped: not up-to-date, locked, etc. | |
2880 | * | |
2881 | * This function is called with the page table lock taken. In the split ptlock | |
2882 | * case the page table lock only protects only those entries which belong to | |
2883 | * the page table corresponding to the fault address. | |
2884 | * | |
2885 | * This function doesn't cross the VMA boundaries, in order to call map_pages() | |
2886 | * only once. | |
2887 | * | |
2888 | * fault_around_pages() defines how many pages we'll try to map. | |
2889 | * do_fault_around() expects it to return a power of two less than or equal to | |
2890 | * PTRS_PER_PTE. | |
2891 | * | |
2892 | * The virtual address of the area that we map is naturally aligned to the | |
2893 | * fault_around_pages() value (and therefore to page order). This way it's | |
2894 | * easier to guarantee that we don't cross page table boundaries. | |
2895 | */ | |
8c6e50b0 KS |
2896 | static void do_fault_around(struct vm_area_struct *vma, unsigned long address, |
2897 | pte_t *pte, pgoff_t pgoff, unsigned int flags) | |
2898 | { | |
aecd6f44 | 2899 | unsigned long start_addr, nr_pages, mask; |
8c6e50b0 KS |
2900 | pgoff_t max_pgoff; |
2901 | struct vm_fault vmf; | |
2902 | int off; | |
2903 | ||
4db0c3c2 | 2904 | nr_pages = READ_ONCE(fault_around_bytes) >> PAGE_SHIFT; |
aecd6f44 KS |
2905 | mask = ~(nr_pages * PAGE_SIZE - 1) & PAGE_MASK; |
2906 | ||
2907 | start_addr = max(address & mask, vma->vm_start); | |
8c6e50b0 KS |
2908 | off = ((address - start_addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1); |
2909 | pte -= off; | |
2910 | pgoff -= off; | |
2911 | ||
2912 | /* | |
2913 | * max_pgoff is either end of page table or end of vma | |
850e9c69 | 2914 | * or fault_around_pages() from pgoff, depending what is nearest. |
8c6e50b0 KS |
2915 | */ |
2916 | max_pgoff = pgoff - ((start_addr >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) + | |
2917 | PTRS_PER_PTE - 1; | |
2918 | max_pgoff = min3(max_pgoff, vma_pages(vma) + vma->vm_pgoff - 1, | |
aecd6f44 | 2919 | pgoff + nr_pages - 1); |
8c6e50b0 KS |
2920 | |
2921 | /* Check if it makes any sense to call ->map_pages */ | |
2922 | while (!pte_none(*pte)) { | |
2923 | if (++pgoff > max_pgoff) | |
2924 | return; | |
2925 | start_addr += PAGE_SIZE; | |
2926 | if (start_addr >= vma->vm_end) | |
2927 | return; | |
2928 | pte++; | |
2929 | } | |
2930 | ||
2931 | vmf.virtual_address = (void __user *) start_addr; | |
2932 | vmf.pte = pte; | |
2933 | vmf.pgoff = pgoff; | |
2934 | vmf.max_pgoff = max_pgoff; | |
2935 | vmf.flags = flags; | |
2936 | vma->vm_ops->map_pages(vma, &vmf); | |
2937 | } | |
2938 | ||
e655fb29 KS |
2939 | static int do_read_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
2940 | unsigned long address, pmd_t *pmd, | |
2941 | pgoff_t pgoff, unsigned int flags, pte_t orig_pte) | |
2942 | { | |
2943 | struct page *fault_page; | |
2944 | spinlock_t *ptl; | |
3bb97794 | 2945 | pte_t *pte; |
8c6e50b0 KS |
2946 | int ret = 0; |
2947 | ||
2948 | /* | |
2949 | * Let's call ->map_pages() first and use ->fault() as fallback | |
2950 | * if page by the offset is not ready to be mapped (cold cache or | |
2951 | * something). | |
2952 | */ | |
9b4bdd2f | 2953 | if (vma->vm_ops->map_pages && fault_around_bytes >> PAGE_SHIFT > 1) { |
8c6e50b0 KS |
2954 | pte = pte_offset_map_lock(mm, pmd, address, &ptl); |
2955 | do_fault_around(vma, address, pte, pgoff, flags); | |
2956 | if (!pte_same(*pte, orig_pte)) | |
2957 | goto unlock_out; | |
2958 | pte_unmap_unlock(pte, ptl); | |
2959 | } | |
e655fb29 | 2960 | |
2e4cdab0 | 2961 | ret = __do_fault(vma, address, pgoff, flags, NULL, &fault_page); |
e655fb29 KS |
2962 | if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY))) |
2963 | return ret; | |
2964 | ||
2965 | pte = pte_offset_map_lock(mm, pmd, address, &ptl); | |
2966 | if (unlikely(!pte_same(*pte, orig_pte))) { | |
2967 | pte_unmap_unlock(pte, ptl); | |
2968 | unlock_page(fault_page); | |
2969 | page_cache_release(fault_page); | |
2970 | return ret; | |
2971 | } | |
3bb97794 | 2972 | do_set_pte(vma, address, fault_page, pte, false, false); |
e655fb29 | 2973 | unlock_page(fault_page); |
8c6e50b0 KS |
2974 | unlock_out: |
2975 | pte_unmap_unlock(pte, ptl); | |
e655fb29 KS |
2976 | return ret; |
2977 | } | |
2978 | ||
ec47c3b9 KS |
2979 | static int do_cow_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
2980 | unsigned long address, pmd_t *pmd, | |
2981 | pgoff_t pgoff, unsigned int flags, pte_t orig_pte) | |
2982 | { | |
2983 | struct page *fault_page, *new_page; | |
00501b53 | 2984 | struct mem_cgroup *memcg; |
ec47c3b9 | 2985 | spinlock_t *ptl; |
3bb97794 | 2986 | pte_t *pte; |
ec47c3b9 KS |
2987 | int ret; |
2988 | ||
2989 | if (unlikely(anon_vma_prepare(vma))) | |
2990 | return VM_FAULT_OOM; | |
2991 | ||
2992 | new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address); | |
2993 | if (!new_page) | |
2994 | return VM_FAULT_OOM; | |
2995 | ||
00501b53 | 2996 | if (mem_cgroup_try_charge(new_page, mm, GFP_KERNEL, &memcg)) { |
ec47c3b9 KS |
2997 | page_cache_release(new_page); |
2998 | return VM_FAULT_OOM; | |
2999 | } | |
3000 | ||
2e4cdab0 | 3001 | ret = __do_fault(vma, address, pgoff, flags, new_page, &fault_page); |
ec47c3b9 KS |
3002 | if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY))) |
3003 | goto uncharge_out; | |
3004 | ||
2e4cdab0 MW |
3005 | if (fault_page) |
3006 | copy_user_highpage(new_page, fault_page, address, vma); | |
ec47c3b9 KS |
3007 | __SetPageUptodate(new_page); |
3008 | ||
3009 | pte = pte_offset_map_lock(mm, pmd, address, &ptl); | |
3010 | if (unlikely(!pte_same(*pte, orig_pte))) { | |
3011 | pte_unmap_unlock(pte, ptl); | |
2e4cdab0 MW |
3012 | if (fault_page) { |
3013 | unlock_page(fault_page); | |
3014 | page_cache_release(fault_page); | |
3015 | } else { | |
3016 | /* | |
3017 | * The fault handler has no page to lock, so it holds | |
3018 | * i_mmap_lock for read to protect against truncate. | |
3019 | */ | |
3020 | i_mmap_unlock_read(vma->vm_file->f_mapping); | |
3021 | } | |
ec47c3b9 KS |
3022 | goto uncharge_out; |
3023 | } | |
3bb97794 | 3024 | do_set_pte(vma, address, new_page, pte, true, true); |
00501b53 JW |
3025 | mem_cgroup_commit_charge(new_page, memcg, false); |
3026 | lru_cache_add_active_or_unevictable(new_page, vma); | |
ec47c3b9 | 3027 | pte_unmap_unlock(pte, ptl); |
2e4cdab0 MW |
3028 | if (fault_page) { |
3029 | unlock_page(fault_page); | |
3030 | page_cache_release(fault_page); | |
3031 | } else { | |
3032 | /* | |
3033 | * The fault handler has no page to lock, so it holds | |
3034 | * i_mmap_lock for read to protect against truncate. | |
3035 | */ | |
3036 | i_mmap_unlock_read(vma->vm_file->f_mapping); | |
3037 | } | |
ec47c3b9 KS |
3038 | return ret; |
3039 | uncharge_out: | |
00501b53 | 3040 | mem_cgroup_cancel_charge(new_page, memcg); |
ec47c3b9 KS |
3041 | page_cache_release(new_page); |
3042 | return ret; | |
3043 | } | |
3044 | ||
f0c6d4d2 | 3045 | static int do_shared_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
16abfa08 | 3046 | unsigned long address, pmd_t *pmd, |
54cb8821 | 3047 | pgoff_t pgoff, unsigned int flags, pte_t orig_pte) |
1da177e4 | 3048 | { |
f0c6d4d2 KS |
3049 | struct page *fault_page; |
3050 | struct address_space *mapping; | |
8f4e2101 | 3051 | spinlock_t *ptl; |
3bb97794 | 3052 | pte_t *pte; |
f0c6d4d2 | 3053 | int dirtied = 0; |
f0c6d4d2 | 3054 | int ret, tmp; |
1d65f86d | 3055 | |
2e4cdab0 | 3056 | ret = __do_fault(vma, address, pgoff, flags, NULL, &fault_page); |
7eae74af | 3057 | if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY))) |
f0c6d4d2 | 3058 | return ret; |
1da177e4 LT |
3059 | |
3060 | /* | |
f0c6d4d2 KS |
3061 | * Check if the backing address space wants to know that the page is |
3062 | * about to become writable | |
1da177e4 | 3063 | */ |
fb09a464 KS |
3064 | if (vma->vm_ops->page_mkwrite) { |
3065 | unlock_page(fault_page); | |
3066 | tmp = do_page_mkwrite(vma, fault_page, address); | |
3067 | if (unlikely(!tmp || | |
3068 | (tmp & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))) { | |
f0c6d4d2 | 3069 | page_cache_release(fault_page); |
fb09a464 | 3070 | return tmp; |
4294621f | 3071 | } |
fb09a464 KS |
3072 | } |
3073 | ||
f0c6d4d2 KS |
3074 | pte = pte_offset_map_lock(mm, pmd, address, &ptl); |
3075 | if (unlikely(!pte_same(*pte, orig_pte))) { | |
3076 | pte_unmap_unlock(pte, ptl); | |
3077 | unlock_page(fault_page); | |
3078 | page_cache_release(fault_page); | |
3079 | return ret; | |
1da177e4 | 3080 | } |
3bb97794 | 3081 | do_set_pte(vma, address, fault_page, pte, true, false); |
f0c6d4d2 | 3082 | pte_unmap_unlock(pte, ptl); |
b827e496 | 3083 | |
f0c6d4d2 KS |
3084 | if (set_page_dirty(fault_page)) |
3085 | dirtied = 1; | |
d82fa87d AM |
3086 | /* |
3087 | * Take a local copy of the address_space - page.mapping may be zeroed | |
3088 | * by truncate after unlock_page(). The address_space itself remains | |
3089 | * pinned by vma->vm_file's reference. We rely on unlock_page()'s | |
3090 | * release semantics to prevent the compiler from undoing this copying. | |
3091 | */ | |
f0c6d4d2 KS |
3092 | mapping = fault_page->mapping; |
3093 | unlock_page(fault_page); | |
3094 | if ((dirtied || vma->vm_ops->page_mkwrite) && mapping) { | |
3095 | /* | |
3096 | * Some device drivers do not set page.mapping but still | |
3097 | * dirty their pages | |
3098 | */ | |
3099 | balance_dirty_pages_ratelimited(mapping); | |
d08b3851 | 3100 | } |
d00806b1 | 3101 | |
74ec6751 | 3102 | if (!vma->vm_ops->page_mkwrite) |
f0c6d4d2 | 3103 | file_update_time(vma->vm_file); |
b827e496 | 3104 | |
1d65f86d | 3105 | return ret; |
54cb8821 | 3106 | } |
d00806b1 | 3107 | |
9a95f3cf PC |
3108 | /* |
3109 | * We enter with non-exclusive mmap_sem (to exclude vma changes, | |
3110 | * but allow concurrent faults). | |
3111 | * The mmap_sem may have been released depending on flags and our | |
3112 | * return value. See filemap_fault() and __lock_page_or_retry(). | |
3113 | */ | |
9b4bdd2f | 3114 | static int do_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
54cb8821 | 3115 | unsigned long address, pte_t *page_table, pmd_t *pmd, |
30c9f3a9 | 3116 | unsigned int flags, pte_t orig_pte) |
54cb8821 NP |
3117 | { |
3118 | pgoff_t pgoff = (((address & PAGE_MASK) | |
0da7e01f | 3119 | - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; |
54cb8821 | 3120 | |
16abfa08 | 3121 | pte_unmap(page_table); |
6b7339f4 KS |
3122 | /* The VMA was not fully populated on mmap() or missing VM_DONTEXPAND */ |
3123 | if (!vma->vm_ops->fault) | |
3124 | return VM_FAULT_SIGBUS; | |
e655fb29 KS |
3125 | if (!(flags & FAULT_FLAG_WRITE)) |
3126 | return do_read_fault(mm, vma, address, pmd, pgoff, flags, | |
3127 | orig_pte); | |
ec47c3b9 KS |
3128 | if (!(vma->vm_flags & VM_SHARED)) |
3129 | return do_cow_fault(mm, vma, address, pmd, pgoff, flags, | |
3130 | orig_pte); | |
f0c6d4d2 | 3131 | return do_shared_fault(mm, vma, address, pmd, pgoff, flags, orig_pte); |
54cb8821 NP |
3132 | } |
3133 | ||
b19a9939 | 3134 | static int numa_migrate_prep(struct page *page, struct vm_area_struct *vma, |
04bb2f94 RR |
3135 | unsigned long addr, int page_nid, |
3136 | int *flags) | |
9532fec1 MG |
3137 | { |
3138 | get_page(page); | |
3139 | ||
3140 | count_vm_numa_event(NUMA_HINT_FAULTS); | |
04bb2f94 | 3141 | if (page_nid == numa_node_id()) { |
9532fec1 | 3142 | count_vm_numa_event(NUMA_HINT_FAULTS_LOCAL); |
04bb2f94 RR |
3143 | *flags |= TNF_FAULT_LOCAL; |
3144 | } | |
9532fec1 MG |
3145 | |
3146 | return mpol_misplaced(page, vma, addr); | |
3147 | } | |
3148 | ||
b19a9939 | 3149 | static int do_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, |
d10e63f2 MG |
3150 | unsigned long addr, pte_t pte, pte_t *ptep, pmd_t *pmd) |
3151 | { | |
4daae3b4 | 3152 | struct page *page = NULL; |
d10e63f2 | 3153 | spinlock_t *ptl; |
8191acbd | 3154 | int page_nid = -1; |
90572890 | 3155 | int last_cpupid; |
cbee9f88 | 3156 | int target_nid; |
b8593bfd | 3157 | bool migrated = false; |
b191f9b1 | 3158 | bool was_writable = pte_write(pte); |
6688cc05 | 3159 | int flags = 0; |
d10e63f2 | 3160 | |
c0e7cad9 MG |
3161 | /* A PROT_NONE fault should not end up here */ |
3162 | BUG_ON(!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE))); | |
3163 | ||
d10e63f2 MG |
3164 | /* |
3165 | * The "pte" at this point cannot be used safely without | |
3166 | * validation through pte_unmap_same(). It's of NUMA type but | |
3167 | * the pfn may be screwed if the read is non atomic. | |
3168 | * | |
4d942466 MG |
3169 | * We can safely just do a "set_pte_at()", because the old |
3170 | * page table entry is not accessible, so there would be no | |
3171 | * concurrent hardware modifications to the PTE. | |
d10e63f2 MG |
3172 | */ |
3173 | ptl = pte_lockptr(mm, pmd); | |
3174 | spin_lock(ptl); | |
4daae3b4 MG |
3175 | if (unlikely(!pte_same(*ptep, pte))) { |
3176 | pte_unmap_unlock(ptep, ptl); | |
3177 | goto out; | |
3178 | } | |
3179 | ||
4d942466 MG |
3180 | /* Make it present again */ |
3181 | pte = pte_modify(pte, vma->vm_page_prot); | |
3182 | pte = pte_mkyoung(pte); | |
b191f9b1 MG |
3183 | if (was_writable) |
3184 | pte = pte_mkwrite(pte); | |
d10e63f2 MG |
3185 | set_pte_at(mm, addr, ptep, pte); |
3186 | update_mmu_cache(vma, addr, ptep); | |
3187 | ||
3188 | page = vm_normal_page(vma, addr, pte); | |
3189 | if (!page) { | |
3190 | pte_unmap_unlock(ptep, ptl); | |
3191 | return 0; | |
3192 | } | |
3193 | ||
6688cc05 | 3194 | /* |
bea66fbd MG |
3195 | * Avoid grouping on RO pages in general. RO pages shouldn't hurt as |
3196 | * much anyway since they can be in shared cache state. This misses | |
3197 | * the case where a mapping is writable but the process never writes | |
3198 | * to it but pte_write gets cleared during protection updates and | |
3199 | * pte_dirty has unpredictable behaviour between PTE scan updates, | |
3200 | * background writeback, dirty balancing and application behaviour. | |
6688cc05 | 3201 | */ |
bea66fbd | 3202 | if (!(vma->vm_flags & VM_WRITE)) |
6688cc05 PZ |
3203 | flags |= TNF_NO_GROUP; |
3204 | ||
dabe1d99 RR |
3205 | /* |
3206 | * Flag if the page is shared between multiple address spaces. This | |
3207 | * is later used when determining whether to group tasks together | |
3208 | */ | |
3209 | if (page_mapcount(page) > 1 && (vma->vm_flags & VM_SHARED)) | |
3210 | flags |= TNF_SHARED; | |
3211 | ||
90572890 | 3212 | last_cpupid = page_cpupid_last(page); |
8191acbd | 3213 | page_nid = page_to_nid(page); |
04bb2f94 | 3214 | target_nid = numa_migrate_prep(page, vma, addr, page_nid, &flags); |
d10e63f2 | 3215 | pte_unmap_unlock(ptep, ptl); |
4daae3b4 | 3216 | if (target_nid == -1) { |
4daae3b4 MG |
3217 | put_page(page); |
3218 | goto out; | |
3219 | } | |
3220 | ||
3221 | /* Migrate to the requested node */ | |
1bc115d8 | 3222 | migrated = migrate_misplaced_page(page, vma, target_nid); |
6688cc05 | 3223 | if (migrated) { |
8191acbd | 3224 | page_nid = target_nid; |
6688cc05 | 3225 | flags |= TNF_MIGRATED; |
074c2381 MG |
3226 | } else |
3227 | flags |= TNF_MIGRATE_FAIL; | |
4daae3b4 MG |
3228 | |
3229 | out: | |
8191acbd | 3230 | if (page_nid != -1) |
6688cc05 | 3231 | task_numa_fault(last_cpupid, page_nid, 1, flags); |
d10e63f2 MG |
3232 | return 0; |
3233 | } | |
3234 | ||
1da177e4 LT |
3235 | /* |
3236 | * These routines also need to handle stuff like marking pages dirty | |
3237 | * and/or accessed for architectures that don't do it in hardware (most | |
3238 | * RISC architectures). The early dirtying is also good on the i386. | |
3239 | * | |
3240 | * There is also a hook called "update_mmu_cache()" that architectures | |
3241 | * with external mmu caches can use to update those (ie the Sparc or | |
3242 | * PowerPC hashed page tables that act as extended TLBs). | |
3243 | * | |
c74df32c HD |
3244 | * We enter with non-exclusive mmap_sem (to exclude vma changes, |
3245 | * but allow concurrent faults), and pte mapped but not yet locked. | |
9a95f3cf PC |
3246 | * We return with pte unmapped and unlocked. |
3247 | * | |
3248 | * The mmap_sem may have been released depending on flags and our | |
3249 | * return value. See filemap_fault() and __lock_page_or_retry(). | |
1da177e4 | 3250 | */ |
c0292554 | 3251 | static int handle_pte_fault(struct mm_struct *mm, |
71e3aac0 AA |
3252 | struct vm_area_struct *vma, unsigned long address, |
3253 | pte_t *pte, pmd_t *pmd, unsigned int flags) | |
1da177e4 LT |
3254 | { |
3255 | pte_t entry; | |
8f4e2101 | 3256 | spinlock_t *ptl; |
1da177e4 | 3257 | |
e37c6982 CB |
3258 | /* |
3259 | * some architectures can have larger ptes than wordsize, | |
3260 | * e.g.ppc44x-defconfig has CONFIG_PTE_64BIT=y and CONFIG_32BIT=y, | |
3261 | * so READ_ONCE or ACCESS_ONCE cannot guarantee atomic accesses. | |
3262 | * The code below just needs a consistent view for the ifs and | |
3263 | * we later double check anyway with the ptl lock held. So here | |
3264 | * a barrier will do. | |
3265 | */ | |
3266 | entry = *pte; | |
3267 | barrier(); | |
1da177e4 | 3268 | if (!pte_present(entry)) { |
65500d23 | 3269 | if (pte_none(entry)) { |
b5330628 ON |
3270 | if (vma_is_anonymous(vma)) |
3271 | return do_anonymous_page(mm, vma, address, | |
3272 | pte, pmd, flags); | |
3273 | else | |
6b7339f4 KS |
3274 | return do_fault(mm, vma, address, pte, pmd, |
3275 | flags, entry); | |
65500d23 | 3276 | } |
65500d23 | 3277 | return do_swap_page(mm, vma, address, |
30c9f3a9 | 3278 | pte, pmd, flags, entry); |
1da177e4 LT |
3279 | } |
3280 | ||
8a0516ed | 3281 | if (pte_protnone(entry)) |
d10e63f2 MG |
3282 | return do_numa_page(mm, vma, address, entry, pte, pmd); |
3283 | ||
4c21e2f2 | 3284 | ptl = pte_lockptr(mm, pmd); |
8f4e2101 HD |
3285 | spin_lock(ptl); |
3286 | if (unlikely(!pte_same(*pte, entry))) | |
3287 | goto unlock; | |
30c9f3a9 | 3288 | if (flags & FAULT_FLAG_WRITE) { |
1da177e4 | 3289 | if (!pte_write(entry)) |
8f4e2101 HD |
3290 | return do_wp_page(mm, vma, address, |
3291 | pte, pmd, ptl, entry); | |
1da177e4 LT |
3292 | entry = pte_mkdirty(entry); |
3293 | } | |
3294 | entry = pte_mkyoung(entry); | |
30c9f3a9 | 3295 | if (ptep_set_access_flags(vma, address, pte, entry, flags & FAULT_FLAG_WRITE)) { |
4b3073e1 | 3296 | update_mmu_cache(vma, address, pte); |
1a44e149 AA |
3297 | } else { |
3298 | /* | |
3299 | * This is needed only for protection faults but the arch code | |
3300 | * is not yet telling us if this is a protection fault or not. | |
3301 | * This still avoids useless tlb flushes for .text page faults | |
3302 | * with threads. | |
3303 | */ | |
30c9f3a9 | 3304 | if (flags & FAULT_FLAG_WRITE) |
61c77326 | 3305 | flush_tlb_fix_spurious_fault(vma, address); |
1a44e149 | 3306 | } |
8f4e2101 HD |
3307 | unlock: |
3308 | pte_unmap_unlock(pte, ptl); | |
83c54070 | 3309 | return 0; |
1da177e4 LT |
3310 | } |
3311 | ||
3312 | /* | |
3313 | * By the time we get here, we already hold the mm semaphore | |
9a95f3cf PC |
3314 | * |
3315 | * The mmap_sem may have been released depending on flags and our | |
3316 | * return value. See filemap_fault() and __lock_page_or_retry(). | |
1da177e4 | 3317 | */ |
519e5247 JW |
3318 | static int __handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
3319 | unsigned long address, unsigned int flags) | |
1da177e4 LT |
3320 | { |
3321 | pgd_t *pgd; | |
3322 | pud_t *pud; | |
3323 | pmd_t *pmd; | |
3324 | pte_t *pte; | |
3325 | ||
ac9b9c66 | 3326 | if (unlikely(is_vm_hugetlb_page(vma))) |
30c9f3a9 | 3327 | return hugetlb_fault(mm, vma, address, flags); |
1da177e4 | 3328 | |
1da177e4 | 3329 | pgd = pgd_offset(mm, address); |
1da177e4 LT |
3330 | pud = pud_alloc(mm, pgd, address); |
3331 | if (!pud) | |
c74df32c | 3332 | return VM_FAULT_OOM; |
1da177e4 LT |
3333 | pmd = pmd_alloc(mm, pud, address); |
3334 | if (!pmd) | |
c74df32c | 3335 | return VM_FAULT_OOM; |
71e3aac0 | 3336 | if (pmd_none(*pmd) && transparent_hugepage_enabled(vma)) { |
c0292554 | 3337 | int ret = VM_FAULT_FALLBACK; |
71e3aac0 | 3338 | if (!vma->vm_ops) |
c0292554 KS |
3339 | ret = do_huge_pmd_anonymous_page(mm, vma, address, |
3340 | pmd, flags); | |
3341 | if (!(ret & VM_FAULT_FALLBACK)) | |
3342 | return ret; | |
71e3aac0 AA |
3343 | } else { |
3344 | pmd_t orig_pmd = *pmd; | |
1f1d06c3 DR |
3345 | int ret; |
3346 | ||
71e3aac0 AA |
3347 | barrier(); |
3348 | if (pmd_trans_huge(orig_pmd)) { | |
a1dd450b WD |
3349 | unsigned int dirty = flags & FAULT_FLAG_WRITE; |
3350 | ||
e53289c0 LT |
3351 | /* |
3352 | * If the pmd is splitting, return and retry the | |
3353 | * the fault. Alternative: wait until the split | |
3354 | * is done, and goto retry. | |
3355 | */ | |
3356 | if (pmd_trans_splitting(orig_pmd)) | |
3357 | return 0; | |
3358 | ||
8a0516ed | 3359 | if (pmd_protnone(orig_pmd)) |
4daae3b4 | 3360 | return do_huge_pmd_numa_page(mm, vma, address, |
d10e63f2 MG |
3361 | orig_pmd, pmd); |
3362 | ||
3d59eebc | 3363 | if (dirty && !pmd_write(orig_pmd)) { |
1f1d06c3 DR |
3364 | ret = do_huge_pmd_wp_page(mm, vma, address, pmd, |
3365 | orig_pmd); | |
9845cbbd KS |
3366 | if (!(ret & VM_FAULT_FALLBACK)) |
3367 | return ret; | |
a1dd450b WD |
3368 | } else { |
3369 | huge_pmd_set_accessed(mm, vma, address, pmd, | |
3370 | orig_pmd, dirty); | |
9845cbbd | 3371 | return 0; |
1f1d06c3 | 3372 | } |
71e3aac0 AA |
3373 | } |
3374 | } | |
3375 | ||
3376 | /* | |
3377 | * Use __pte_alloc instead of pte_alloc_map, because we can't | |
3378 | * run pte_offset_map on the pmd, if an huge pmd could | |
3379 | * materialize from under us from a different thread. | |
3380 | */ | |
4fd01770 MG |
3381 | if (unlikely(pmd_none(*pmd)) && |
3382 | unlikely(__pte_alloc(mm, vma, pmd, address))) | |
c74df32c | 3383 | return VM_FAULT_OOM; |
71e3aac0 AA |
3384 | /* if an huge pmd materialized from under us just retry later */ |
3385 | if (unlikely(pmd_trans_huge(*pmd))) | |
3386 | return 0; | |
3387 | /* | |
3388 | * A regular pmd is established and it can't morph into a huge pmd | |
3389 | * from under us anymore at this point because we hold the mmap_sem | |
3390 | * read mode and khugepaged takes it in write mode. So now it's | |
3391 | * safe to run pte_offset_map(). | |
3392 | */ | |
3393 | pte = pte_offset_map(pmd, address); | |
1da177e4 | 3394 | |
30c9f3a9 | 3395 | return handle_pte_fault(mm, vma, address, pte, pmd, flags); |
1da177e4 LT |
3396 | } |
3397 | ||
9a95f3cf PC |
3398 | /* |
3399 | * By the time we get here, we already hold the mm semaphore | |
3400 | * | |
3401 | * The mmap_sem may have been released depending on flags and our | |
3402 | * return value. See filemap_fault() and __lock_page_or_retry(). | |
3403 | */ | |
519e5247 JW |
3404 | int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
3405 | unsigned long address, unsigned int flags) | |
3406 | { | |
3407 | int ret; | |
3408 | ||
3409 | __set_current_state(TASK_RUNNING); | |
3410 | ||
3411 | count_vm_event(PGFAULT); | |
3412 | mem_cgroup_count_vm_event(mm, PGFAULT); | |
3413 | ||
3414 | /* do counter updates before entering really critical section. */ | |
3415 | check_sync_rss_stat(current); | |
3416 | ||
3417 | /* | |
3418 | * Enable the memcg OOM handling for faults triggered in user | |
3419 | * space. Kernel faults are handled more gracefully. | |
3420 | */ | |
3421 | if (flags & FAULT_FLAG_USER) | |
49426420 | 3422 | mem_cgroup_oom_enable(); |
519e5247 JW |
3423 | |
3424 | ret = __handle_mm_fault(mm, vma, address, flags); | |
3425 | ||
49426420 JW |
3426 | if (flags & FAULT_FLAG_USER) { |
3427 | mem_cgroup_oom_disable(); | |
3428 | /* | |
3429 | * The task may have entered a memcg OOM situation but | |
3430 | * if the allocation error was handled gracefully (no | |
3431 | * VM_FAULT_OOM), there is no need to kill anything. | |
3432 | * Just clean up the OOM state peacefully. | |
3433 | */ | |
3434 | if (task_in_memcg_oom(current) && !(ret & VM_FAULT_OOM)) | |
3435 | mem_cgroup_oom_synchronize(false); | |
3436 | } | |
3812c8c8 | 3437 | |
519e5247 JW |
3438 | return ret; |
3439 | } | |
e1d6d01a | 3440 | EXPORT_SYMBOL_GPL(handle_mm_fault); |
519e5247 | 3441 | |
1da177e4 LT |
3442 | #ifndef __PAGETABLE_PUD_FOLDED |
3443 | /* | |
3444 | * Allocate page upper directory. | |
872fec16 | 3445 | * We've already handled the fast-path in-line. |
1da177e4 | 3446 | */ |
1bb3630e | 3447 | int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address) |
1da177e4 | 3448 | { |
c74df32c HD |
3449 | pud_t *new = pud_alloc_one(mm, address); |
3450 | if (!new) | |
1bb3630e | 3451 | return -ENOMEM; |
1da177e4 | 3452 | |
362a61ad NP |
3453 | smp_wmb(); /* See comment in __pte_alloc */ |
3454 | ||
872fec16 | 3455 | spin_lock(&mm->page_table_lock); |
1bb3630e | 3456 | if (pgd_present(*pgd)) /* Another has populated it */ |
5e541973 | 3457 | pud_free(mm, new); |
1bb3630e HD |
3458 | else |
3459 | pgd_populate(mm, pgd, new); | |
c74df32c | 3460 | spin_unlock(&mm->page_table_lock); |
1bb3630e | 3461 | return 0; |
1da177e4 LT |
3462 | } |
3463 | #endif /* __PAGETABLE_PUD_FOLDED */ | |
3464 | ||
3465 | #ifndef __PAGETABLE_PMD_FOLDED | |
3466 | /* | |
3467 | * Allocate page middle directory. | |
872fec16 | 3468 | * We've already handled the fast-path in-line. |
1da177e4 | 3469 | */ |
1bb3630e | 3470 | int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address) |
1da177e4 | 3471 | { |
c74df32c HD |
3472 | pmd_t *new = pmd_alloc_one(mm, address); |
3473 | if (!new) | |
1bb3630e | 3474 | return -ENOMEM; |
1da177e4 | 3475 | |
362a61ad NP |
3476 | smp_wmb(); /* See comment in __pte_alloc */ |
3477 | ||
872fec16 | 3478 | spin_lock(&mm->page_table_lock); |
1da177e4 | 3479 | #ifndef __ARCH_HAS_4LEVEL_HACK |
dc6c9a35 KS |
3480 | if (!pud_present(*pud)) { |
3481 | mm_inc_nr_pmds(mm); | |
1bb3630e | 3482 | pud_populate(mm, pud, new); |
dc6c9a35 | 3483 | } else /* Another has populated it */ |
5e541973 | 3484 | pmd_free(mm, new); |
dc6c9a35 KS |
3485 | #else |
3486 | if (!pgd_present(*pud)) { | |
3487 | mm_inc_nr_pmds(mm); | |
1bb3630e | 3488 | pgd_populate(mm, pud, new); |
dc6c9a35 KS |
3489 | } else /* Another has populated it */ |
3490 | pmd_free(mm, new); | |
1da177e4 | 3491 | #endif /* __ARCH_HAS_4LEVEL_HACK */ |
c74df32c | 3492 | spin_unlock(&mm->page_table_lock); |
1bb3630e | 3493 | return 0; |
e0f39591 | 3494 | } |
1da177e4 LT |
3495 | #endif /* __PAGETABLE_PMD_FOLDED */ |
3496 | ||
1b36ba81 | 3497 | static int __follow_pte(struct mm_struct *mm, unsigned long address, |
f8ad0f49 JW |
3498 | pte_t **ptepp, spinlock_t **ptlp) |
3499 | { | |
3500 | pgd_t *pgd; | |
3501 | pud_t *pud; | |
3502 | pmd_t *pmd; | |
3503 | pte_t *ptep; | |
3504 | ||
3505 | pgd = pgd_offset(mm, address); | |
3506 | if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd))) | |
3507 | goto out; | |
3508 | ||
3509 | pud = pud_offset(pgd, address); | |
3510 | if (pud_none(*pud) || unlikely(pud_bad(*pud))) | |
3511 | goto out; | |
3512 | ||
3513 | pmd = pmd_offset(pud, address); | |
f66055ab | 3514 | VM_BUG_ON(pmd_trans_huge(*pmd)); |
f8ad0f49 JW |
3515 | if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd))) |
3516 | goto out; | |
3517 | ||
3518 | /* We cannot handle huge page PFN maps. Luckily they don't exist. */ | |
3519 | if (pmd_huge(*pmd)) | |
3520 | goto out; | |
3521 | ||
3522 | ptep = pte_offset_map_lock(mm, pmd, address, ptlp); | |
3523 | if (!ptep) | |
3524 | goto out; | |
3525 | if (!pte_present(*ptep)) | |
3526 | goto unlock; | |
3527 | *ptepp = ptep; | |
3528 | return 0; | |
3529 | unlock: | |
3530 | pte_unmap_unlock(ptep, *ptlp); | |
3531 | out: | |
3532 | return -EINVAL; | |
3533 | } | |
3534 | ||
1b36ba81 NK |
3535 | static inline int follow_pte(struct mm_struct *mm, unsigned long address, |
3536 | pte_t **ptepp, spinlock_t **ptlp) | |
3537 | { | |
3538 | int res; | |
3539 | ||
3540 | /* (void) is needed to make gcc happy */ | |
3541 | (void) __cond_lock(*ptlp, | |
3542 | !(res = __follow_pte(mm, address, ptepp, ptlp))); | |
3543 | return res; | |
3544 | } | |
3545 | ||
3b6748e2 JW |
3546 | /** |
3547 | * follow_pfn - look up PFN at a user virtual address | |
3548 | * @vma: memory mapping | |
3549 | * @address: user virtual address | |
3550 | * @pfn: location to store found PFN | |
3551 | * | |
3552 | * Only IO mappings and raw PFN mappings are allowed. | |
3553 | * | |
3554 | * Returns zero and the pfn at @pfn on success, -ve otherwise. | |
3555 | */ | |
3556 | int follow_pfn(struct vm_area_struct *vma, unsigned long address, | |
3557 | unsigned long *pfn) | |
3558 | { | |
3559 | int ret = -EINVAL; | |
3560 | spinlock_t *ptl; | |
3561 | pte_t *ptep; | |
3562 | ||
3563 | if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) | |
3564 | return ret; | |
3565 | ||
3566 | ret = follow_pte(vma->vm_mm, address, &ptep, &ptl); | |
3567 | if (ret) | |
3568 | return ret; | |
3569 | *pfn = pte_pfn(*ptep); | |
3570 | pte_unmap_unlock(ptep, ptl); | |
3571 | return 0; | |
3572 | } | |
3573 | EXPORT_SYMBOL(follow_pfn); | |
3574 | ||
28b2ee20 | 3575 | #ifdef CONFIG_HAVE_IOREMAP_PROT |
d87fe660 | 3576 | int follow_phys(struct vm_area_struct *vma, |
3577 | unsigned long address, unsigned int flags, | |
3578 | unsigned long *prot, resource_size_t *phys) | |
28b2ee20 | 3579 | { |
03668a4d | 3580 | int ret = -EINVAL; |
28b2ee20 RR |
3581 | pte_t *ptep, pte; |
3582 | spinlock_t *ptl; | |
28b2ee20 | 3583 | |
d87fe660 | 3584 | if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) |
3585 | goto out; | |
28b2ee20 | 3586 | |
03668a4d | 3587 | if (follow_pte(vma->vm_mm, address, &ptep, &ptl)) |
d87fe660 | 3588 | goto out; |
28b2ee20 | 3589 | pte = *ptep; |
03668a4d | 3590 | |
28b2ee20 RR |
3591 | if ((flags & FOLL_WRITE) && !pte_write(pte)) |
3592 | goto unlock; | |
28b2ee20 RR |
3593 | |
3594 | *prot = pgprot_val(pte_pgprot(pte)); | |
03668a4d | 3595 | *phys = (resource_size_t)pte_pfn(pte) << PAGE_SHIFT; |
28b2ee20 | 3596 | |
03668a4d | 3597 | ret = 0; |
28b2ee20 RR |
3598 | unlock: |
3599 | pte_unmap_unlock(ptep, ptl); | |
3600 | out: | |
d87fe660 | 3601 | return ret; |
28b2ee20 RR |
3602 | } |
3603 | ||
3604 | int generic_access_phys(struct vm_area_struct *vma, unsigned long addr, | |
3605 | void *buf, int len, int write) | |
3606 | { | |
3607 | resource_size_t phys_addr; | |
3608 | unsigned long prot = 0; | |
2bc7273b | 3609 | void __iomem *maddr; |
28b2ee20 RR |
3610 | int offset = addr & (PAGE_SIZE-1); |
3611 | ||
d87fe660 | 3612 | if (follow_phys(vma, addr, write, &prot, &phys_addr)) |
28b2ee20 RR |
3613 | return -EINVAL; |
3614 | ||
9cb12d7b | 3615 | maddr = ioremap_prot(phys_addr, PAGE_ALIGN(len + offset), prot); |
28b2ee20 RR |
3616 | if (write) |
3617 | memcpy_toio(maddr + offset, buf, len); | |
3618 | else | |
3619 | memcpy_fromio(buf, maddr + offset, len); | |
3620 | iounmap(maddr); | |
3621 | ||
3622 | return len; | |
3623 | } | |
5a73633e | 3624 | EXPORT_SYMBOL_GPL(generic_access_phys); |
28b2ee20 RR |
3625 | #endif |
3626 | ||
0ec76a11 | 3627 | /* |
206cb636 SW |
3628 | * Access another process' address space as given in mm. If non-NULL, use the |
3629 | * given task for page fault accounting. | |
0ec76a11 | 3630 | */ |
206cb636 SW |
3631 | static int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm, |
3632 | unsigned long addr, void *buf, int len, int write) | |
0ec76a11 | 3633 | { |
0ec76a11 | 3634 | struct vm_area_struct *vma; |
0ec76a11 DH |
3635 | void *old_buf = buf; |
3636 | ||
0ec76a11 | 3637 | down_read(&mm->mmap_sem); |
183ff22b | 3638 | /* ignore errors, just check how much was successfully transferred */ |
0ec76a11 DH |
3639 | while (len) { |
3640 | int bytes, ret, offset; | |
3641 | void *maddr; | |
28b2ee20 | 3642 | struct page *page = NULL; |
0ec76a11 DH |
3643 | |
3644 | ret = get_user_pages(tsk, mm, addr, 1, | |
3645 | write, 1, &page, &vma); | |
28b2ee20 | 3646 | if (ret <= 0) { |
dbffcd03 RR |
3647 | #ifndef CONFIG_HAVE_IOREMAP_PROT |
3648 | break; | |
3649 | #else | |
28b2ee20 RR |
3650 | /* |
3651 | * Check if this is a VM_IO | VM_PFNMAP VMA, which | |
3652 | * we can access using slightly different code. | |
3653 | */ | |
28b2ee20 | 3654 | vma = find_vma(mm, addr); |
fe936dfc | 3655 | if (!vma || vma->vm_start > addr) |
28b2ee20 RR |
3656 | break; |
3657 | if (vma->vm_ops && vma->vm_ops->access) | |
3658 | ret = vma->vm_ops->access(vma, addr, buf, | |
3659 | len, write); | |
3660 | if (ret <= 0) | |
28b2ee20 RR |
3661 | break; |
3662 | bytes = ret; | |
dbffcd03 | 3663 | #endif |
0ec76a11 | 3664 | } else { |
28b2ee20 RR |
3665 | bytes = len; |
3666 | offset = addr & (PAGE_SIZE-1); | |
3667 | if (bytes > PAGE_SIZE-offset) | |
3668 | bytes = PAGE_SIZE-offset; | |
3669 | ||
3670 | maddr = kmap(page); | |
3671 | if (write) { | |
3672 | copy_to_user_page(vma, page, addr, | |
3673 | maddr + offset, buf, bytes); | |
3674 | set_page_dirty_lock(page); | |
3675 | } else { | |
3676 | copy_from_user_page(vma, page, addr, | |
3677 | buf, maddr + offset, bytes); | |
3678 | } | |
3679 | kunmap(page); | |
3680 | page_cache_release(page); | |
0ec76a11 | 3681 | } |
0ec76a11 DH |
3682 | len -= bytes; |
3683 | buf += bytes; | |
3684 | addr += bytes; | |
3685 | } | |
3686 | up_read(&mm->mmap_sem); | |
0ec76a11 DH |
3687 | |
3688 | return buf - old_buf; | |
3689 | } | |
03252919 | 3690 | |
5ddd36b9 | 3691 | /** |
ae91dbfc | 3692 | * access_remote_vm - access another process' address space |
5ddd36b9 SW |
3693 | * @mm: the mm_struct of the target address space |
3694 | * @addr: start address to access | |
3695 | * @buf: source or destination buffer | |
3696 | * @len: number of bytes to transfer | |
3697 | * @write: whether the access is a write | |
3698 | * | |
3699 | * The caller must hold a reference on @mm. | |
3700 | */ | |
3701 | int access_remote_vm(struct mm_struct *mm, unsigned long addr, | |
3702 | void *buf, int len, int write) | |
3703 | { | |
3704 | return __access_remote_vm(NULL, mm, addr, buf, len, write); | |
3705 | } | |
3706 | ||
206cb636 SW |
3707 | /* |
3708 | * Access another process' address space. | |
3709 | * Source/target buffer must be kernel space, | |
3710 | * Do not walk the page table directly, use get_user_pages | |
3711 | */ | |
3712 | int access_process_vm(struct task_struct *tsk, unsigned long addr, | |
3713 | void *buf, int len, int write) | |
3714 | { | |
3715 | struct mm_struct *mm; | |
3716 | int ret; | |
3717 | ||
3718 | mm = get_task_mm(tsk); | |
3719 | if (!mm) | |
3720 | return 0; | |
3721 | ||
3722 | ret = __access_remote_vm(tsk, mm, addr, buf, len, write); | |
3723 | mmput(mm); | |
3724 | ||
3725 | return ret; | |
3726 | } | |
3727 | ||
03252919 AK |
3728 | /* |
3729 | * Print the name of a VMA. | |
3730 | */ | |
3731 | void print_vma_addr(char *prefix, unsigned long ip) | |
3732 | { | |
3733 | struct mm_struct *mm = current->mm; | |
3734 | struct vm_area_struct *vma; | |
3735 | ||
e8bff74a IM |
3736 | /* |
3737 | * Do not print if we are in atomic | |
3738 | * contexts (in exception stacks, etc.): | |
3739 | */ | |
3740 | if (preempt_count()) | |
3741 | return; | |
3742 | ||
03252919 AK |
3743 | down_read(&mm->mmap_sem); |
3744 | vma = find_vma(mm, ip); | |
3745 | if (vma && vma->vm_file) { | |
3746 | struct file *f = vma->vm_file; | |
3747 | char *buf = (char *)__get_free_page(GFP_KERNEL); | |
3748 | if (buf) { | |
2fbc57c5 | 3749 | char *p; |
03252919 | 3750 | |
9bf39ab2 | 3751 | p = file_path(f, buf, PAGE_SIZE); |
03252919 AK |
3752 | if (IS_ERR(p)) |
3753 | p = "?"; | |
2fbc57c5 | 3754 | printk("%s%s[%lx+%lx]", prefix, kbasename(p), |
03252919 AK |
3755 | vma->vm_start, |
3756 | vma->vm_end - vma->vm_start); | |
3757 | free_page((unsigned long)buf); | |
3758 | } | |
3759 | } | |
51a07e50 | 3760 | up_read(&mm->mmap_sem); |
03252919 | 3761 | } |
3ee1afa3 | 3762 | |
662bbcb2 | 3763 | #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP) |
9ec23531 | 3764 | void __might_fault(const char *file, int line) |
3ee1afa3 | 3765 | { |
95156f00 PZ |
3766 | /* |
3767 | * Some code (nfs/sunrpc) uses socket ops on kernel memory while | |
3768 | * holding the mmap_sem, this is safe because kernel memory doesn't | |
3769 | * get paged out, therefore we'll never actually fault, and the | |
3770 | * below annotations will generate false positives. | |
3771 | */ | |
3772 | if (segment_eq(get_fs(), KERNEL_DS)) | |
3773 | return; | |
9ec23531 | 3774 | if (pagefault_disabled()) |
662bbcb2 | 3775 | return; |
9ec23531 DH |
3776 | __might_sleep(file, line, 0); |
3777 | #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) | |
662bbcb2 | 3778 | if (current->mm) |
3ee1afa3 | 3779 | might_lock_read(¤t->mm->mmap_sem); |
9ec23531 | 3780 | #endif |
3ee1afa3 | 3781 | } |
9ec23531 | 3782 | EXPORT_SYMBOL(__might_fault); |
3ee1afa3 | 3783 | #endif |
47ad8475 AA |
3784 | |
3785 | #if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLBFS) | |
3786 | static void clear_gigantic_page(struct page *page, | |
3787 | unsigned long addr, | |
3788 | unsigned int pages_per_huge_page) | |
3789 | { | |
3790 | int i; | |
3791 | struct page *p = page; | |
3792 | ||
3793 | might_sleep(); | |
3794 | for (i = 0; i < pages_per_huge_page; | |
3795 | i++, p = mem_map_next(p, page, i)) { | |
3796 | cond_resched(); | |
3797 | clear_user_highpage(p, addr + i * PAGE_SIZE); | |
3798 | } | |
3799 | } | |
3800 | void clear_huge_page(struct page *page, | |
3801 | unsigned long addr, unsigned int pages_per_huge_page) | |
3802 | { | |
3803 | int i; | |
3804 | ||
3805 | if (unlikely(pages_per_huge_page > MAX_ORDER_NR_PAGES)) { | |
3806 | clear_gigantic_page(page, addr, pages_per_huge_page); | |
3807 | return; | |
3808 | } | |
3809 | ||
3810 | might_sleep(); | |
3811 | for (i = 0; i < pages_per_huge_page; i++) { | |
3812 | cond_resched(); | |
3813 | clear_user_highpage(page + i, addr + i * PAGE_SIZE); | |
3814 | } | |
3815 | } | |
3816 | ||
3817 | static void copy_user_gigantic_page(struct page *dst, struct page *src, | |
3818 | unsigned long addr, | |
3819 | struct vm_area_struct *vma, | |
3820 | unsigned int pages_per_huge_page) | |
3821 | { | |
3822 | int i; | |
3823 | struct page *dst_base = dst; | |
3824 | struct page *src_base = src; | |
3825 | ||
3826 | for (i = 0; i < pages_per_huge_page; ) { | |
3827 | cond_resched(); | |
3828 | copy_user_highpage(dst, src, addr + i*PAGE_SIZE, vma); | |
3829 | ||
3830 | i++; | |
3831 | dst = mem_map_next(dst, dst_base, i); | |
3832 | src = mem_map_next(src, src_base, i); | |
3833 | } | |
3834 | } | |
3835 | ||
3836 | void copy_user_huge_page(struct page *dst, struct page *src, | |
3837 | unsigned long addr, struct vm_area_struct *vma, | |
3838 | unsigned int pages_per_huge_page) | |
3839 | { | |
3840 | int i; | |
3841 | ||
3842 | if (unlikely(pages_per_huge_page > MAX_ORDER_NR_PAGES)) { | |
3843 | copy_user_gigantic_page(dst, src, addr, vma, | |
3844 | pages_per_huge_page); | |
3845 | return; | |
3846 | } | |
3847 | ||
3848 | might_sleep(); | |
3849 | for (i = 0; i < pages_per_huge_page; i++) { | |
3850 | cond_resched(); | |
3851 | copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma); | |
3852 | } | |
3853 | } | |
3854 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLBFS */ | |
49076ec2 | 3855 | |
40b64acd | 3856 | #if USE_SPLIT_PTE_PTLOCKS && ALLOC_SPLIT_PTLOCKS |
b35f1819 KS |
3857 | |
3858 | static struct kmem_cache *page_ptl_cachep; | |
3859 | ||
3860 | void __init ptlock_cache_init(void) | |
3861 | { | |
3862 | page_ptl_cachep = kmem_cache_create("page->ptl", sizeof(spinlock_t), 0, | |
3863 | SLAB_PANIC, NULL); | |
3864 | } | |
3865 | ||
539edb58 | 3866 | bool ptlock_alloc(struct page *page) |
49076ec2 KS |
3867 | { |
3868 | spinlock_t *ptl; | |
3869 | ||
b35f1819 | 3870 | ptl = kmem_cache_alloc(page_ptl_cachep, GFP_KERNEL); |
49076ec2 KS |
3871 | if (!ptl) |
3872 | return false; | |
539edb58 | 3873 | page->ptl = ptl; |
49076ec2 KS |
3874 | return true; |
3875 | } | |
3876 | ||
539edb58 | 3877 | void ptlock_free(struct page *page) |
49076ec2 | 3878 | { |
b35f1819 | 3879 | kmem_cache_free(page_ptl_cachep, page->ptl); |
49076ec2 KS |
3880 | } |
3881 | #endif |