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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> | |
48 | #include <linux/rmap.h> | |
49 | #include <linux/module.h> | |
50 | #include <linux/init.h> | |
51 | ||
52 | #include <asm/pgalloc.h> | |
53 | #include <asm/uaccess.h> | |
54 | #include <asm/tlb.h> | |
55 | #include <asm/tlbflush.h> | |
56 | #include <asm/pgtable.h> | |
57 | ||
58 | #include <linux/swapops.h> | |
59 | #include <linux/elf.h> | |
60 | ||
d41dee36 | 61 | #ifndef CONFIG_NEED_MULTIPLE_NODES |
1da177e4 LT |
62 | /* use the per-pgdat data instead for discontigmem - mbligh */ |
63 | unsigned long max_mapnr; | |
64 | struct page *mem_map; | |
65 | ||
66 | EXPORT_SYMBOL(max_mapnr); | |
67 | EXPORT_SYMBOL(mem_map); | |
68 | #endif | |
69 | ||
70 | unsigned long num_physpages; | |
71 | /* | |
72 | * A number of key systems in x86 including ioremap() rely on the assumption | |
73 | * that high_memory defines the upper bound on direct map memory, then end | |
74 | * of ZONE_NORMAL. Under CONFIG_DISCONTIG this means that max_low_pfn and | |
75 | * highstart_pfn must be the same; there must be no gap between ZONE_NORMAL | |
76 | * and ZONE_HIGHMEM. | |
77 | */ | |
78 | void * high_memory; | |
79 | unsigned long vmalloc_earlyreserve; | |
80 | ||
81 | EXPORT_SYMBOL(num_physpages); | |
82 | EXPORT_SYMBOL(high_memory); | |
83 | EXPORT_SYMBOL(vmalloc_earlyreserve); | |
84 | ||
85 | /* | |
86 | * If a p?d_bad entry is found while walking page tables, report | |
87 | * the error, before resetting entry to p?d_none. Usually (but | |
88 | * very seldom) called out from the p?d_none_or_clear_bad macros. | |
89 | */ | |
90 | ||
91 | void pgd_clear_bad(pgd_t *pgd) | |
92 | { | |
93 | pgd_ERROR(*pgd); | |
94 | pgd_clear(pgd); | |
95 | } | |
96 | ||
97 | void pud_clear_bad(pud_t *pud) | |
98 | { | |
99 | pud_ERROR(*pud); | |
100 | pud_clear(pud); | |
101 | } | |
102 | ||
103 | void pmd_clear_bad(pmd_t *pmd) | |
104 | { | |
105 | pmd_ERROR(*pmd); | |
106 | pmd_clear(pmd); | |
107 | } | |
108 | ||
109 | /* | |
110 | * Note: this doesn't free the actual pages themselves. That | |
111 | * has been handled earlier when unmapping all the memory regions. | |
112 | */ | |
e0da382c | 113 | static void free_pte_range(struct mmu_gather *tlb, pmd_t *pmd) |
1da177e4 | 114 | { |
e0da382c HD |
115 | struct page *page = pmd_page(*pmd); |
116 | pmd_clear(pmd); | |
117 | pte_free_tlb(tlb, page); | |
118 | dec_page_state(nr_page_table_pages); | |
119 | tlb->mm->nr_ptes--; | |
1da177e4 LT |
120 | } |
121 | ||
e0da382c HD |
122 | static inline void free_pmd_range(struct mmu_gather *tlb, pud_t *pud, |
123 | unsigned long addr, unsigned long end, | |
124 | unsigned long floor, unsigned long ceiling) | |
1da177e4 LT |
125 | { |
126 | pmd_t *pmd; | |
127 | unsigned long next; | |
e0da382c | 128 | unsigned long start; |
1da177e4 | 129 | |
e0da382c | 130 | start = addr; |
1da177e4 | 131 | pmd = pmd_offset(pud, addr); |
1da177e4 LT |
132 | do { |
133 | next = pmd_addr_end(addr, end); | |
134 | if (pmd_none_or_clear_bad(pmd)) | |
135 | continue; | |
e0da382c | 136 | free_pte_range(tlb, pmd); |
1da177e4 LT |
137 | } while (pmd++, addr = next, addr != end); |
138 | ||
e0da382c HD |
139 | start &= PUD_MASK; |
140 | if (start < floor) | |
141 | return; | |
142 | if (ceiling) { | |
143 | ceiling &= PUD_MASK; | |
144 | if (!ceiling) | |
145 | return; | |
1da177e4 | 146 | } |
e0da382c HD |
147 | if (end - 1 > ceiling - 1) |
148 | return; | |
149 | ||
150 | pmd = pmd_offset(pud, start); | |
151 | pud_clear(pud); | |
152 | pmd_free_tlb(tlb, pmd); | |
1da177e4 LT |
153 | } |
154 | ||
e0da382c HD |
155 | static inline void free_pud_range(struct mmu_gather *tlb, pgd_t *pgd, |
156 | unsigned long addr, unsigned long end, | |
157 | unsigned long floor, unsigned long ceiling) | |
1da177e4 LT |
158 | { |
159 | pud_t *pud; | |
160 | unsigned long next; | |
e0da382c | 161 | unsigned long start; |
1da177e4 | 162 | |
e0da382c | 163 | start = addr; |
1da177e4 | 164 | pud = pud_offset(pgd, addr); |
1da177e4 LT |
165 | do { |
166 | next = pud_addr_end(addr, end); | |
167 | if (pud_none_or_clear_bad(pud)) | |
168 | continue; | |
e0da382c | 169 | free_pmd_range(tlb, pud, addr, next, floor, ceiling); |
1da177e4 LT |
170 | } while (pud++, addr = next, addr != end); |
171 | ||
e0da382c HD |
172 | start &= PGDIR_MASK; |
173 | if (start < floor) | |
174 | return; | |
175 | if (ceiling) { | |
176 | ceiling &= PGDIR_MASK; | |
177 | if (!ceiling) | |
178 | return; | |
1da177e4 | 179 | } |
e0da382c HD |
180 | if (end - 1 > ceiling - 1) |
181 | return; | |
182 | ||
183 | pud = pud_offset(pgd, start); | |
184 | pgd_clear(pgd); | |
185 | pud_free_tlb(tlb, pud); | |
1da177e4 LT |
186 | } |
187 | ||
188 | /* | |
e0da382c HD |
189 | * This function frees user-level page tables of a process. |
190 | * | |
1da177e4 LT |
191 | * Must be called with pagetable lock held. |
192 | */ | |
3bf5ee95 | 193 | void free_pgd_range(struct mmu_gather **tlb, |
e0da382c HD |
194 | unsigned long addr, unsigned long end, |
195 | unsigned long floor, unsigned long ceiling) | |
1da177e4 LT |
196 | { |
197 | pgd_t *pgd; | |
198 | unsigned long next; | |
e0da382c HD |
199 | unsigned long start; |
200 | ||
201 | /* | |
202 | * The next few lines have given us lots of grief... | |
203 | * | |
204 | * Why are we testing PMD* at this top level? Because often | |
205 | * there will be no work to do at all, and we'd prefer not to | |
206 | * go all the way down to the bottom just to discover that. | |
207 | * | |
208 | * Why all these "- 1"s? Because 0 represents both the bottom | |
209 | * of the address space and the top of it (using -1 for the | |
210 | * top wouldn't help much: the masks would do the wrong thing). | |
211 | * The rule is that addr 0 and floor 0 refer to the bottom of | |
212 | * the address space, but end 0 and ceiling 0 refer to the top | |
213 | * Comparisons need to use "end - 1" and "ceiling - 1" (though | |
214 | * that end 0 case should be mythical). | |
215 | * | |
216 | * Wherever addr is brought up or ceiling brought down, we must | |
217 | * be careful to reject "the opposite 0" before it confuses the | |
218 | * subsequent tests. But what about where end is brought down | |
219 | * by PMD_SIZE below? no, end can't go down to 0 there. | |
220 | * | |
221 | * Whereas we round start (addr) and ceiling down, by different | |
222 | * masks at different levels, in order to test whether a table | |
223 | * now has no other vmas using it, so can be freed, we don't | |
224 | * bother to round floor or end up - the tests don't need that. | |
225 | */ | |
1da177e4 | 226 | |
e0da382c HD |
227 | addr &= PMD_MASK; |
228 | if (addr < floor) { | |
229 | addr += PMD_SIZE; | |
230 | if (!addr) | |
231 | return; | |
232 | } | |
233 | if (ceiling) { | |
234 | ceiling &= PMD_MASK; | |
235 | if (!ceiling) | |
236 | return; | |
237 | } | |
238 | if (end - 1 > ceiling - 1) | |
239 | end -= PMD_SIZE; | |
240 | if (addr > end - 1) | |
241 | return; | |
242 | ||
243 | start = addr; | |
3bf5ee95 | 244 | pgd = pgd_offset((*tlb)->mm, addr); |
1da177e4 LT |
245 | do { |
246 | next = pgd_addr_end(addr, end); | |
247 | if (pgd_none_or_clear_bad(pgd)) | |
248 | continue; | |
3bf5ee95 | 249 | free_pud_range(*tlb, pgd, addr, next, floor, ceiling); |
1da177e4 | 250 | } while (pgd++, addr = next, addr != end); |
e0da382c | 251 | |
3bf5ee95 HD |
252 | if (!tlb_is_full_mm(*tlb)) |
253 | flush_tlb_pgtables((*tlb)->mm, start, end); | |
e0da382c HD |
254 | } |
255 | ||
256 | void free_pgtables(struct mmu_gather **tlb, struct vm_area_struct *vma, | |
3bf5ee95 | 257 | unsigned long floor, unsigned long ceiling) |
e0da382c HD |
258 | { |
259 | while (vma) { | |
260 | struct vm_area_struct *next = vma->vm_next; | |
261 | unsigned long addr = vma->vm_start; | |
262 | ||
3bf5ee95 HD |
263 | if (is_hugepage_only_range(vma->vm_mm, addr, HPAGE_SIZE)) { |
264 | hugetlb_free_pgd_range(tlb, addr, vma->vm_end, | |
e0da382c | 265 | floor, next? next->vm_start: ceiling); |
3bf5ee95 HD |
266 | } else { |
267 | /* | |
268 | * Optimization: gather nearby vmas into one call down | |
269 | */ | |
270 | while (next && next->vm_start <= vma->vm_end + PMD_SIZE | |
271 | && !is_hugepage_only_range(vma->vm_mm, next->vm_start, | |
272 | HPAGE_SIZE)) { | |
273 | vma = next; | |
274 | next = vma->vm_next; | |
275 | } | |
276 | free_pgd_range(tlb, addr, vma->vm_end, | |
277 | floor, next? next->vm_start: ceiling); | |
278 | } | |
e0da382c HD |
279 | vma = next; |
280 | } | |
1da177e4 LT |
281 | } |
282 | ||
3bf5ee95 HD |
283 | pte_t fastcall *pte_alloc_map(struct mm_struct *mm, pmd_t *pmd, |
284 | unsigned long address) | |
1da177e4 LT |
285 | { |
286 | if (!pmd_present(*pmd)) { | |
287 | struct page *new; | |
288 | ||
289 | spin_unlock(&mm->page_table_lock); | |
290 | new = pte_alloc_one(mm, address); | |
291 | spin_lock(&mm->page_table_lock); | |
292 | if (!new) | |
293 | return NULL; | |
294 | /* | |
295 | * Because we dropped the lock, we should re-check the | |
296 | * entry, as somebody else could have populated it.. | |
297 | */ | |
298 | if (pmd_present(*pmd)) { | |
299 | pte_free(new); | |
300 | goto out; | |
301 | } | |
302 | mm->nr_ptes++; | |
303 | inc_page_state(nr_page_table_pages); | |
304 | pmd_populate(mm, pmd, new); | |
305 | } | |
306 | out: | |
307 | return pte_offset_map(pmd, address); | |
308 | } | |
309 | ||
310 | pte_t fastcall * pte_alloc_kernel(struct mm_struct *mm, pmd_t *pmd, unsigned long address) | |
311 | { | |
312 | if (!pmd_present(*pmd)) { | |
313 | pte_t *new; | |
314 | ||
315 | spin_unlock(&mm->page_table_lock); | |
316 | new = pte_alloc_one_kernel(mm, address); | |
317 | spin_lock(&mm->page_table_lock); | |
318 | if (!new) | |
319 | return NULL; | |
320 | ||
321 | /* | |
322 | * Because we dropped the lock, we should re-check the | |
323 | * entry, as somebody else could have populated it.. | |
324 | */ | |
325 | if (pmd_present(*pmd)) { | |
326 | pte_free_kernel(new); | |
327 | goto out; | |
328 | } | |
329 | pmd_populate_kernel(mm, pmd, new); | |
330 | } | |
331 | out: | |
332 | return pte_offset_kernel(pmd, address); | |
333 | } | |
334 | ||
335 | /* | |
336 | * copy one vm_area from one task to the other. Assumes the page tables | |
337 | * already present in the new task to be cleared in the whole range | |
338 | * covered by this vma. | |
339 | * | |
340 | * dst->page_table_lock is held on entry and exit, | |
341 | * but may be dropped within p[mg]d_alloc() and pte_alloc_map(). | |
342 | */ | |
343 | ||
344 | static inline void | |
345 | copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm, | |
346 | pte_t *dst_pte, pte_t *src_pte, unsigned long vm_flags, | |
347 | unsigned long addr) | |
348 | { | |
349 | pte_t pte = *src_pte; | |
350 | struct page *page; | |
351 | unsigned long pfn; | |
352 | ||
353 | /* pte contains position in swap or file, so copy. */ | |
354 | if (unlikely(!pte_present(pte))) { | |
355 | if (!pte_file(pte)) { | |
356 | swap_duplicate(pte_to_swp_entry(pte)); | |
357 | /* make sure dst_mm is on swapoff's mmlist. */ | |
358 | if (unlikely(list_empty(&dst_mm->mmlist))) { | |
359 | spin_lock(&mmlist_lock); | |
360 | list_add(&dst_mm->mmlist, &src_mm->mmlist); | |
361 | spin_unlock(&mmlist_lock); | |
362 | } | |
363 | } | |
364 | set_pte_at(dst_mm, addr, dst_pte, pte); | |
365 | return; | |
366 | } | |
367 | ||
368 | pfn = pte_pfn(pte); | |
369 | /* the pte points outside of valid memory, the | |
370 | * mapping is assumed to be good, meaningful | |
371 | * and not mapped via rmap - duplicate the | |
372 | * mapping as is. | |
373 | */ | |
374 | page = NULL; | |
375 | if (pfn_valid(pfn)) | |
376 | page = pfn_to_page(pfn); | |
377 | ||
378 | if (!page || PageReserved(page)) { | |
379 | set_pte_at(dst_mm, addr, dst_pte, pte); | |
380 | return; | |
381 | } | |
382 | ||
383 | /* | |
384 | * If it's a COW mapping, write protect it both | |
385 | * in the parent and the child | |
386 | */ | |
387 | if ((vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE) { | |
388 | ptep_set_wrprotect(src_mm, addr, src_pte); | |
389 | pte = *src_pte; | |
390 | } | |
391 | ||
392 | /* | |
393 | * If it's a shared mapping, mark it clean in | |
394 | * the child | |
395 | */ | |
396 | if (vm_flags & VM_SHARED) | |
397 | pte = pte_mkclean(pte); | |
398 | pte = pte_mkold(pte); | |
399 | get_page(page); | |
400 | inc_mm_counter(dst_mm, rss); | |
401 | if (PageAnon(page)) | |
402 | inc_mm_counter(dst_mm, anon_rss); | |
403 | set_pte_at(dst_mm, addr, dst_pte, pte); | |
404 | page_dup_rmap(page); | |
405 | } | |
406 | ||
407 | static int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm, | |
408 | pmd_t *dst_pmd, pmd_t *src_pmd, struct vm_area_struct *vma, | |
409 | unsigned long addr, unsigned long end) | |
410 | { | |
411 | pte_t *src_pte, *dst_pte; | |
412 | unsigned long vm_flags = vma->vm_flags; | |
413 | int progress; | |
414 | ||
415 | again: | |
416 | dst_pte = pte_alloc_map(dst_mm, dst_pmd, addr); | |
417 | if (!dst_pte) | |
418 | return -ENOMEM; | |
419 | src_pte = pte_offset_map_nested(src_pmd, addr); | |
420 | ||
421 | progress = 0; | |
422 | spin_lock(&src_mm->page_table_lock); | |
423 | do { | |
424 | /* | |
425 | * We are holding two locks at this point - either of them | |
426 | * could generate latencies in another task on another CPU. | |
427 | */ | |
428 | if (progress >= 32 && (need_resched() || | |
429 | need_lockbreak(&src_mm->page_table_lock) || | |
430 | need_lockbreak(&dst_mm->page_table_lock))) | |
431 | break; | |
432 | if (pte_none(*src_pte)) { | |
433 | progress++; | |
434 | continue; | |
435 | } | |
436 | copy_one_pte(dst_mm, src_mm, dst_pte, src_pte, vm_flags, addr); | |
437 | progress += 8; | |
438 | } while (dst_pte++, src_pte++, addr += PAGE_SIZE, addr != end); | |
439 | spin_unlock(&src_mm->page_table_lock); | |
440 | ||
441 | pte_unmap_nested(src_pte - 1); | |
442 | pte_unmap(dst_pte - 1); | |
443 | cond_resched_lock(&dst_mm->page_table_lock); | |
444 | if (addr != end) | |
445 | goto again; | |
446 | return 0; | |
447 | } | |
448 | ||
449 | static inline int copy_pmd_range(struct mm_struct *dst_mm, struct mm_struct *src_mm, | |
450 | pud_t *dst_pud, pud_t *src_pud, struct vm_area_struct *vma, | |
451 | unsigned long addr, unsigned long end) | |
452 | { | |
453 | pmd_t *src_pmd, *dst_pmd; | |
454 | unsigned long next; | |
455 | ||
456 | dst_pmd = pmd_alloc(dst_mm, dst_pud, addr); | |
457 | if (!dst_pmd) | |
458 | return -ENOMEM; | |
459 | src_pmd = pmd_offset(src_pud, addr); | |
460 | do { | |
461 | next = pmd_addr_end(addr, end); | |
462 | if (pmd_none_or_clear_bad(src_pmd)) | |
463 | continue; | |
464 | if (copy_pte_range(dst_mm, src_mm, dst_pmd, src_pmd, | |
465 | vma, addr, next)) | |
466 | return -ENOMEM; | |
467 | } while (dst_pmd++, src_pmd++, addr = next, addr != end); | |
468 | return 0; | |
469 | } | |
470 | ||
471 | static inline int copy_pud_range(struct mm_struct *dst_mm, struct mm_struct *src_mm, | |
472 | pgd_t *dst_pgd, pgd_t *src_pgd, struct vm_area_struct *vma, | |
473 | unsigned long addr, unsigned long end) | |
474 | { | |
475 | pud_t *src_pud, *dst_pud; | |
476 | unsigned long next; | |
477 | ||
478 | dst_pud = pud_alloc(dst_mm, dst_pgd, addr); | |
479 | if (!dst_pud) | |
480 | return -ENOMEM; | |
481 | src_pud = pud_offset(src_pgd, addr); | |
482 | do { | |
483 | next = pud_addr_end(addr, end); | |
484 | if (pud_none_or_clear_bad(src_pud)) | |
485 | continue; | |
486 | if (copy_pmd_range(dst_mm, src_mm, dst_pud, src_pud, | |
487 | vma, addr, next)) | |
488 | return -ENOMEM; | |
489 | } while (dst_pud++, src_pud++, addr = next, addr != end); | |
490 | return 0; | |
491 | } | |
492 | ||
493 | int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm, | |
494 | struct vm_area_struct *vma) | |
495 | { | |
496 | pgd_t *src_pgd, *dst_pgd; | |
497 | unsigned long next; | |
498 | unsigned long addr = vma->vm_start; | |
499 | unsigned long end = vma->vm_end; | |
500 | ||
d992895b NP |
501 | /* |
502 | * Don't copy ptes where a page fault will fill them correctly. | |
503 | * Fork becomes much lighter when there are big shared or private | |
504 | * readonly mappings. The tradeoff is that copy_page_range is more | |
505 | * efficient than faulting. | |
506 | */ | |
507 | if (!(vma->vm_flags & (VM_HUGETLB|VM_NONLINEAR|VM_RESERVED))) { | |
508 | if (!vma->anon_vma) | |
509 | return 0; | |
510 | } | |
511 | ||
1da177e4 LT |
512 | if (is_vm_hugetlb_page(vma)) |
513 | return copy_hugetlb_page_range(dst_mm, src_mm, vma); | |
514 | ||
515 | dst_pgd = pgd_offset(dst_mm, addr); | |
516 | src_pgd = pgd_offset(src_mm, addr); | |
517 | do { | |
518 | next = pgd_addr_end(addr, end); | |
519 | if (pgd_none_or_clear_bad(src_pgd)) | |
520 | continue; | |
521 | if (copy_pud_range(dst_mm, src_mm, dst_pgd, src_pgd, | |
522 | vma, addr, next)) | |
523 | return -ENOMEM; | |
524 | } while (dst_pgd++, src_pgd++, addr = next, addr != end); | |
525 | return 0; | |
526 | } | |
527 | ||
528 | static void zap_pte_range(struct mmu_gather *tlb, pmd_t *pmd, | |
529 | unsigned long addr, unsigned long end, | |
530 | struct zap_details *details) | |
531 | { | |
532 | pte_t *pte; | |
533 | ||
534 | pte = pte_offset_map(pmd, addr); | |
535 | do { | |
536 | pte_t ptent = *pte; | |
537 | if (pte_none(ptent)) | |
538 | continue; | |
539 | if (pte_present(ptent)) { | |
540 | struct page *page = NULL; | |
541 | unsigned long pfn = pte_pfn(ptent); | |
542 | if (pfn_valid(pfn)) { | |
543 | page = pfn_to_page(pfn); | |
544 | if (PageReserved(page)) | |
545 | page = NULL; | |
546 | } | |
547 | if (unlikely(details) && page) { | |
548 | /* | |
549 | * unmap_shared_mapping_pages() wants to | |
550 | * invalidate cache without truncating: | |
551 | * unmap shared but keep private pages. | |
552 | */ | |
553 | if (details->check_mapping && | |
554 | details->check_mapping != page->mapping) | |
555 | continue; | |
556 | /* | |
557 | * Each page->index must be checked when | |
558 | * invalidating or truncating nonlinear. | |
559 | */ | |
560 | if (details->nonlinear_vma && | |
561 | (page->index < details->first_index || | |
562 | page->index > details->last_index)) | |
563 | continue; | |
564 | } | |
a600388d ZA |
565 | ptent = ptep_get_and_clear_full(tlb->mm, addr, pte, |
566 | tlb->fullmm); | |
1da177e4 LT |
567 | tlb_remove_tlb_entry(tlb, pte, addr); |
568 | if (unlikely(!page)) | |
569 | continue; | |
570 | if (unlikely(details) && details->nonlinear_vma | |
571 | && linear_page_index(details->nonlinear_vma, | |
572 | addr) != page->index) | |
573 | set_pte_at(tlb->mm, addr, pte, | |
574 | pgoff_to_pte(page->index)); | |
575 | if (pte_dirty(ptent)) | |
576 | set_page_dirty(page); | |
577 | if (PageAnon(page)) | |
578 | dec_mm_counter(tlb->mm, anon_rss); | |
579 | else if (pte_young(ptent)) | |
580 | mark_page_accessed(page); | |
581 | tlb->freed++; | |
582 | page_remove_rmap(page); | |
583 | tlb_remove_page(tlb, page); | |
584 | continue; | |
585 | } | |
586 | /* | |
587 | * If details->check_mapping, we leave swap entries; | |
588 | * if details->nonlinear_vma, we leave file entries. | |
589 | */ | |
590 | if (unlikely(details)) | |
591 | continue; | |
592 | if (!pte_file(ptent)) | |
593 | free_swap_and_cache(pte_to_swp_entry(ptent)); | |
a600388d | 594 | pte_clear_full(tlb->mm, addr, pte, tlb->fullmm); |
1da177e4 LT |
595 | } while (pte++, addr += PAGE_SIZE, addr != end); |
596 | pte_unmap(pte - 1); | |
597 | } | |
598 | ||
599 | static inline void zap_pmd_range(struct mmu_gather *tlb, pud_t *pud, | |
600 | unsigned long addr, unsigned long end, | |
601 | struct zap_details *details) | |
602 | { | |
603 | pmd_t *pmd; | |
604 | unsigned long next; | |
605 | ||
606 | pmd = pmd_offset(pud, addr); | |
607 | do { | |
608 | next = pmd_addr_end(addr, end); | |
609 | if (pmd_none_or_clear_bad(pmd)) | |
610 | continue; | |
611 | zap_pte_range(tlb, pmd, addr, next, details); | |
612 | } while (pmd++, addr = next, addr != end); | |
613 | } | |
614 | ||
615 | static inline void zap_pud_range(struct mmu_gather *tlb, pgd_t *pgd, | |
616 | unsigned long addr, unsigned long end, | |
617 | struct zap_details *details) | |
618 | { | |
619 | pud_t *pud; | |
620 | unsigned long next; | |
621 | ||
622 | pud = pud_offset(pgd, addr); | |
623 | do { | |
624 | next = pud_addr_end(addr, end); | |
625 | if (pud_none_or_clear_bad(pud)) | |
626 | continue; | |
627 | zap_pmd_range(tlb, pud, addr, next, details); | |
628 | } while (pud++, addr = next, addr != end); | |
629 | } | |
630 | ||
631 | static void unmap_page_range(struct mmu_gather *tlb, struct vm_area_struct *vma, | |
632 | unsigned long addr, unsigned long end, | |
633 | struct zap_details *details) | |
634 | { | |
635 | pgd_t *pgd; | |
636 | unsigned long next; | |
637 | ||
638 | if (details && !details->check_mapping && !details->nonlinear_vma) | |
639 | details = NULL; | |
640 | ||
641 | BUG_ON(addr >= end); | |
642 | tlb_start_vma(tlb, vma); | |
643 | pgd = pgd_offset(vma->vm_mm, addr); | |
644 | do { | |
645 | next = pgd_addr_end(addr, end); | |
646 | if (pgd_none_or_clear_bad(pgd)) | |
647 | continue; | |
648 | zap_pud_range(tlb, pgd, addr, next, details); | |
649 | } while (pgd++, addr = next, addr != end); | |
650 | tlb_end_vma(tlb, vma); | |
651 | } | |
652 | ||
653 | #ifdef CONFIG_PREEMPT | |
654 | # define ZAP_BLOCK_SIZE (8 * PAGE_SIZE) | |
655 | #else | |
656 | /* No preempt: go for improved straight-line efficiency */ | |
657 | # define ZAP_BLOCK_SIZE (1024 * PAGE_SIZE) | |
658 | #endif | |
659 | ||
660 | /** | |
661 | * unmap_vmas - unmap a range of memory covered by a list of vma's | |
662 | * @tlbp: address of the caller's struct mmu_gather | |
663 | * @mm: the controlling mm_struct | |
664 | * @vma: the starting vma | |
665 | * @start_addr: virtual address at which to start unmapping | |
666 | * @end_addr: virtual address at which to end unmapping | |
667 | * @nr_accounted: Place number of unmapped pages in vm-accountable vma's here | |
668 | * @details: details of nonlinear truncation or shared cache invalidation | |
669 | * | |
ee39b37b | 670 | * Returns the end address of the unmapping (restart addr if interrupted). |
1da177e4 LT |
671 | * |
672 | * Unmap all pages in the vma list. Called under page_table_lock. | |
673 | * | |
674 | * We aim to not hold page_table_lock for too long (for scheduling latency | |
675 | * reasons). So zap pages in ZAP_BLOCK_SIZE bytecounts. This means we need to | |
676 | * return the ending mmu_gather to the caller. | |
677 | * | |
678 | * Only addresses between `start' and `end' will be unmapped. | |
679 | * | |
680 | * The VMA list must be sorted in ascending virtual address order. | |
681 | * | |
682 | * unmap_vmas() assumes that the caller will flush the whole unmapped address | |
683 | * range after unmap_vmas() returns. So the only responsibility here is to | |
684 | * ensure that any thus-far unmapped pages are flushed before unmap_vmas() | |
685 | * drops the lock and schedules. | |
686 | */ | |
ee39b37b | 687 | unsigned long unmap_vmas(struct mmu_gather **tlbp, struct mm_struct *mm, |
1da177e4 LT |
688 | struct vm_area_struct *vma, unsigned long start_addr, |
689 | unsigned long end_addr, unsigned long *nr_accounted, | |
690 | struct zap_details *details) | |
691 | { | |
692 | unsigned long zap_bytes = ZAP_BLOCK_SIZE; | |
693 | unsigned long tlb_start = 0; /* For tlb_finish_mmu */ | |
694 | int tlb_start_valid = 0; | |
ee39b37b | 695 | unsigned long start = start_addr; |
1da177e4 LT |
696 | spinlock_t *i_mmap_lock = details? details->i_mmap_lock: NULL; |
697 | int fullmm = tlb_is_full_mm(*tlbp); | |
698 | ||
699 | for ( ; vma && vma->vm_start < end_addr; vma = vma->vm_next) { | |
1da177e4 LT |
700 | unsigned long end; |
701 | ||
702 | start = max(vma->vm_start, start_addr); | |
703 | if (start >= vma->vm_end) | |
704 | continue; | |
705 | end = min(vma->vm_end, end_addr); | |
706 | if (end <= vma->vm_start) | |
707 | continue; | |
708 | ||
709 | if (vma->vm_flags & VM_ACCOUNT) | |
710 | *nr_accounted += (end - start) >> PAGE_SHIFT; | |
711 | ||
1da177e4 LT |
712 | while (start != end) { |
713 | unsigned long block; | |
714 | ||
715 | if (!tlb_start_valid) { | |
716 | tlb_start = start; | |
717 | tlb_start_valid = 1; | |
718 | } | |
719 | ||
720 | if (is_vm_hugetlb_page(vma)) { | |
721 | block = end - start; | |
722 | unmap_hugepage_range(vma, start, end); | |
723 | } else { | |
724 | block = min(zap_bytes, end - start); | |
725 | unmap_page_range(*tlbp, vma, start, | |
726 | start + block, details); | |
727 | } | |
728 | ||
729 | start += block; | |
730 | zap_bytes -= block; | |
731 | if ((long)zap_bytes > 0) | |
732 | continue; | |
733 | ||
734 | tlb_finish_mmu(*tlbp, tlb_start, start); | |
735 | ||
736 | if (need_resched() || | |
737 | need_lockbreak(&mm->page_table_lock) || | |
738 | (i_mmap_lock && need_lockbreak(i_mmap_lock))) { | |
739 | if (i_mmap_lock) { | |
740 | /* must reset count of rss freed */ | |
741 | *tlbp = tlb_gather_mmu(mm, fullmm); | |
1da177e4 LT |
742 | goto out; |
743 | } | |
744 | spin_unlock(&mm->page_table_lock); | |
745 | cond_resched(); | |
746 | spin_lock(&mm->page_table_lock); | |
747 | } | |
748 | ||
749 | *tlbp = tlb_gather_mmu(mm, fullmm); | |
750 | tlb_start_valid = 0; | |
751 | zap_bytes = ZAP_BLOCK_SIZE; | |
752 | } | |
753 | } | |
754 | out: | |
ee39b37b | 755 | return start; /* which is now the end (or restart) address */ |
1da177e4 LT |
756 | } |
757 | ||
758 | /** | |
759 | * zap_page_range - remove user pages in a given range | |
760 | * @vma: vm_area_struct holding the applicable pages | |
761 | * @address: starting address of pages to zap | |
762 | * @size: number of bytes to zap | |
763 | * @details: details of nonlinear truncation or shared cache invalidation | |
764 | */ | |
ee39b37b | 765 | unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address, |
1da177e4 LT |
766 | unsigned long size, struct zap_details *details) |
767 | { | |
768 | struct mm_struct *mm = vma->vm_mm; | |
769 | struct mmu_gather *tlb; | |
770 | unsigned long end = address + size; | |
771 | unsigned long nr_accounted = 0; | |
772 | ||
773 | if (is_vm_hugetlb_page(vma)) { | |
774 | zap_hugepage_range(vma, address, size); | |
ee39b37b | 775 | return end; |
1da177e4 LT |
776 | } |
777 | ||
778 | lru_add_drain(); | |
779 | spin_lock(&mm->page_table_lock); | |
780 | tlb = tlb_gather_mmu(mm, 0); | |
ee39b37b | 781 | end = unmap_vmas(&tlb, mm, vma, address, end, &nr_accounted, details); |
1da177e4 LT |
782 | tlb_finish_mmu(tlb, address, end); |
783 | spin_unlock(&mm->page_table_lock); | |
ee39b37b | 784 | return end; |
1da177e4 LT |
785 | } |
786 | ||
787 | /* | |
788 | * Do a quick page-table lookup for a single page. | |
789 | * mm->page_table_lock must be held. | |
790 | */ | |
1aaf18ff AM |
791 | static struct page *__follow_page(struct mm_struct *mm, unsigned long address, |
792 | int read, int write, int accessed) | |
1da177e4 LT |
793 | { |
794 | pgd_t *pgd; | |
795 | pud_t *pud; | |
796 | pmd_t *pmd; | |
797 | pte_t *ptep, pte; | |
798 | unsigned long pfn; | |
799 | struct page *page; | |
800 | ||
801 | page = follow_huge_addr(mm, address, write); | |
802 | if (! IS_ERR(page)) | |
803 | return page; | |
804 | ||
805 | pgd = pgd_offset(mm, address); | |
806 | if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd))) | |
807 | goto out; | |
808 | ||
809 | pud = pud_offset(pgd, address); | |
810 | if (pud_none(*pud) || unlikely(pud_bad(*pud))) | |
811 | goto out; | |
812 | ||
813 | pmd = pmd_offset(pud, address); | |
814 | if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd))) | |
815 | goto out; | |
816 | if (pmd_huge(*pmd)) | |
817 | return follow_huge_pmd(mm, address, pmd, write); | |
818 | ||
819 | ptep = pte_offset_map(pmd, address); | |
820 | if (!ptep) | |
821 | goto out; | |
822 | ||
823 | pte = *ptep; | |
824 | pte_unmap(ptep); | |
825 | if (pte_present(pte)) { | |
f33ea7f4 | 826 | if (write && !pte_write(pte)) |
1da177e4 LT |
827 | goto out; |
828 | if (read && !pte_read(pte)) | |
829 | goto out; | |
830 | pfn = pte_pfn(pte); | |
831 | if (pfn_valid(pfn)) { | |
832 | page = pfn_to_page(pfn); | |
f33ea7f4 NP |
833 | if (accessed) { |
834 | if (write && !pte_dirty(pte) &&!PageDirty(page)) | |
835 | set_page_dirty(page); | |
1aaf18ff | 836 | mark_page_accessed(page); |
f33ea7f4 | 837 | } |
1da177e4 LT |
838 | return page; |
839 | } | |
840 | } | |
841 | ||
842 | out: | |
843 | return NULL; | |
844 | } | |
845 | ||
1aaf18ff | 846 | inline struct page * |
1da177e4 LT |
847 | follow_page(struct mm_struct *mm, unsigned long address, int write) |
848 | { | |
1aaf18ff | 849 | return __follow_page(mm, address, 0, write, 1); |
1da177e4 LT |
850 | } |
851 | ||
1aaf18ff AM |
852 | /* |
853 | * check_user_page_readable() can be called frm niterrupt context by oprofile, | |
854 | * so we need to avoid taking any non-irq-safe locks | |
855 | */ | |
856 | int check_user_page_readable(struct mm_struct *mm, unsigned long address) | |
1da177e4 | 857 | { |
1aaf18ff | 858 | return __follow_page(mm, address, 1, 0, 0) != NULL; |
1da177e4 | 859 | } |
1da177e4 LT |
860 | EXPORT_SYMBOL(check_user_page_readable); |
861 | ||
1da177e4 LT |
862 | static inline int |
863 | untouched_anonymous_page(struct mm_struct* mm, struct vm_area_struct *vma, | |
864 | unsigned long address) | |
865 | { | |
866 | pgd_t *pgd; | |
867 | pud_t *pud; | |
868 | pmd_t *pmd; | |
869 | ||
870 | /* Check if the vma is for an anonymous mapping. */ | |
871 | if (vma->vm_ops && vma->vm_ops->nopage) | |
872 | return 0; | |
873 | ||
874 | /* Check if page directory entry exists. */ | |
875 | pgd = pgd_offset(mm, address); | |
876 | if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd))) | |
877 | return 1; | |
878 | ||
879 | pud = pud_offset(pgd, address); | |
880 | if (pud_none(*pud) || unlikely(pud_bad(*pud))) | |
881 | return 1; | |
882 | ||
883 | /* Check if page middle directory entry exists. */ | |
884 | pmd = pmd_offset(pud, address); | |
885 | if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd))) | |
886 | return 1; | |
887 | ||
888 | /* There is a pte slot for 'address' in 'mm'. */ | |
889 | return 0; | |
890 | } | |
891 | ||
1da177e4 LT |
892 | int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, |
893 | unsigned long start, int len, int write, int force, | |
894 | struct page **pages, struct vm_area_struct **vmas) | |
895 | { | |
896 | int i; | |
897 | unsigned int flags; | |
898 | ||
899 | /* | |
900 | * Require read or write permissions. | |
901 | * If 'force' is set, we only require the "MAY" flags. | |
902 | */ | |
903 | flags = write ? (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD); | |
904 | flags &= force ? (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE); | |
905 | i = 0; | |
906 | ||
907 | do { | |
908 | struct vm_area_struct * vma; | |
909 | ||
910 | vma = find_extend_vma(mm, start); | |
911 | if (!vma && in_gate_area(tsk, start)) { | |
912 | unsigned long pg = start & PAGE_MASK; | |
913 | struct vm_area_struct *gate_vma = get_gate_vma(tsk); | |
914 | pgd_t *pgd; | |
915 | pud_t *pud; | |
916 | pmd_t *pmd; | |
917 | pte_t *pte; | |
918 | if (write) /* user gate pages are read-only */ | |
919 | return i ? : -EFAULT; | |
920 | if (pg > TASK_SIZE) | |
921 | pgd = pgd_offset_k(pg); | |
922 | else | |
923 | pgd = pgd_offset_gate(mm, pg); | |
924 | BUG_ON(pgd_none(*pgd)); | |
925 | pud = pud_offset(pgd, pg); | |
926 | BUG_ON(pud_none(*pud)); | |
927 | pmd = pmd_offset(pud, pg); | |
690dbe1c HD |
928 | if (pmd_none(*pmd)) |
929 | return i ? : -EFAULT; | |
1da177e4 | 930 | pte = pte_offset_map(pmd, pg); |
690dbe1c HD |
931 | if (pte_none(*pte)) { |
932 | pte_unmap(pte); | |
933 | return i ? : -EFAULT; | |
934 | } | |
1da177e4 LT |
935 | if (pages) { |
936 | pages[i] = pte_page(*pte); | |
937 | get_page(pages[i]); | |
938 | } | |
939 | pte_unmap(pte); | |
940 | if (vmas) | |
941 | vmas[i] = gate_vma; | |
942 | i++; | |
943 | start += PAGE_SIZE; | |
944 | len--; | |
945 | continue; | |
946 | } | |
947 | ||
948 | if (!vma || (vma->vm_flags & VM_IO) | |
949 | || !(flags & vma->vm_flags)) | |
950 | return i ? : -EFAULT; | |
951 | ||
952 | if (is_vm_hugetlb_page(vma)) { | |
953 | i = follow_hugetlb_page(mm, vma, pages, vmas, | |
954 | &start, &len, i); | |
955 | continue; | |
956 | } | |
957 | spin_lock(&mm->page_table_lock); | |
958 | do { | |
f33ea7f4 | 959 | int write_access = write; |
08ef4729 | 960 | struct page *page; |
1da177e4 LT |
961 | |
962 | cond_resched_lock(&mm->page_table_lock); | |
f33ea7f4 | 963 | while (!(page = follow_page(mm, start, write_access))) { |
a68d2ebc LT |
964 | int ret; |
965 | ||
1da177e4 LT |
966 | /* |
967 | * Shortcut for anonymous pages. We don't want | |
968 | * to force the creation of pages tables for | |
08ef4729 | 969 | * insanely big anonymously mapped areas that |
1da177e4 LT |
970 | * nobody touched so far. This is important |
971 | * for doing a core dump for these mappings. | |
972 | */ | |
4ceb5db9 | 973 | if (!write && untouched_anonymous_page(mm,vma,start)) { |
08ef4729 | 974 | page = ZERO_PAGE(start); |
1da177e4 LT |
975 | break; |
976 | } | |
977 | spin_unlock(&mm->page_table_lock); | |
a68d2ebc LT |
978 | ret = __handle_mm_fault(mm, vma, start, write_access); |
979 | ||
980 | /* | |
981 | * The VM_FAULT_WRITE bit tells us that do_wp_page has | |
982 | * broken COW when necessary, even if maybe_mkwrite | |
983 | * decided not to set pte_write. We can thus safely do | |
984 | * subsequent page lookups as if they were reads. | |
985 | */ | |
986 | if (ret & VM_FAULT_WRITE) | |
f33ea7f4 | 987 | write_access = 0; |
a68d2ebc LT |
988 | |
989 | switch (ret & ~VM_FAULT_WRITE) { | |
1da177e4 LT |
990 | case VM_FAULT_MINOR: |
991 | tsk->min_flt++; | |
992 | break; | |
993 | case VM_FAULT_MAJOR: | |
994 | tsk->maj_flt++; | |
995 | break; | |
996 | case VM_FAULT_SIGBUS: | |
997 | return i ? i : -EFAULT; | |
998 | case VM_FAULT_OOM: | |
999 | return i ? i : -ENOMEM; | |
1000 | default: | |
1001 | BUG(); | |
1002 | } | |
1da177e4 LT |
1003 | spin_lock(&mm->page_table_lock); |
1004 | } | |
1005 | if (pages) { | |
08ef4729 HD |
1006 | pages[i] = page; |
1007 | flush_dcache_page(page); | |
1008 | if (!PageReserved(page)) | |
1009 | page_cache_get(page); | |
1da177e4 LT |
1010 | } |
1011 | if (vmas) | |
1012 | vmas[i] = vma; | |
1013 | i++; | |
1014 | start += PAGE_SIZE; | |
1015 | len--; | |
08ef4729 | 1016 | } while (len && start < vma->vm_end); |
1da177e4 | 1017 | spin_unlock(&mm->page_table_lock); |
08ef4729 | 1018 | } while (len); |
1da177e4 LT |
1019 | return i; |
1020 | } | |
1da177e4 LT |
1021 | EXPORT_SYMBOL(get_user_pages); |
1022 | ||
1023 | static int zeromap_pte_range(struct mm_struct *mm, pmd_t *pmd, | |
1024 | unsigned long addr, unsigned long end, pgprot_t prot) | |
1025 | { | |
1026 | pte_t *pte; | |
1027 | ||
1028 | pte = pte_alloc_map(mm, pmd, addr); | |
1029 | if (!pte) | |
1030 | return -ENOMEM; | |
1031 | do { | |
1032 | pte_t zero_pte = pte_wrprotect(mk_pte(ZERO_PAGE(addr), prot)); | |
1033 | BUG_ON(!pte_none(*pte)); | |
1034 | set_pte_at(mm, addr, pte, zero_pte); | |
1035 | } while (pte++, addr += PAGE_SIZE, addr != end); | |
1036 | pte_unmap(pte - 1); | |
1037 | return 0; | |
1038 | } | |
1039 | ||
1040 | static inline int zeromap_pmd_range(struct mm_struct *mm, pud_t *pud, | |
1041 | unsigned long addr, unsigned long end, pgprot_t prot) | |
1042 | { | |
1043 | pmd_t *pmd; | |
1044 | unsigned long next; | |
1045 | ||
1046 | pmd = pmd_alloc(mm, pud, addr); | |
1047 | if (!pmd) | |
1048 | return -ENOMEM; | |
1049 | do { | |
1050 | next = pmd_addr_end(addr, end); | |
1051 | if (zeromap_pte_range(mm, pmd, addr, next, prot)) | |
1052 | return -ENOMEM; | |
1053 | } while (pmd++, addr = next, addr != end); | |
1054 | return 0; | |
1055 | } | |
1056 | ||
1057 | static inline int zeromap_pud_range(struct mm_struct *mm, pgd_t *pgd, | |
1058 | unsigned long addr, unsigned long end, pgprot_t prot) | |
1059 | { | |
1060 | pud_t *pud; | |
1061 | unsigned long next; | |
1062 | ||
1063 | pud = pud_alloc(mm, pgd, addr); | |
1064 | if (!pud) | |
1065 | return -ENOMEM; | |
1066 | do { | |
1067 | next = pud_addr_end(addr, end); | |
1068 | if (zeromap_pmd_range(mm, pud, addr, next, prot)) | |
1069 | return -ENOMEM; | |
1070 | } while (pud++, addr = next, addr != end); | |
1071 | return 0; | |
1072 | } | |
1073 | ||
1074 | int zeromap_page_range(struct vm_area_struct *vma, | |
1075 | unsigned long addr, unsigned long size, pgprot_t prot) | |
1076 | { | |
1077 | pgd_t *pgd; | |
1078 | unsigned long next; | |
1079 | unsigned long end = addr + size; | |
1080 | struct mm_struct *mm = vma->vm_mm; | |
1081 | int err; | |
1082 | ||
1083 | BUG_ON(addr >= end); | |
1084 | pgd = pgd_offset(mm, addr); | |
1085 | flush_cache_range(vma, addr, end); | |
1086 | spin_lock(&mm->page_table_lock); | |
1087 | do { | |
1088 | next = pgd_addr_end(addr, end); | |
1089 | err = zeromap_pud_range(mm, pgd, addr, next, prot); | |
1090 | if (err) | |
1091 | break; | |
1092 | } while (pgd++, addr = next, addr != end); | |
1093 | spin_unlock(&mm->page_table_lock); | |
1094 | return err; | |
1095 | } | |
1096 | ||
1097 | /* | |
1098 | * maps a range of physical memory into the requested pages. the old | |
1099 | * mappings are removed. any references to nonexistent pages results | |
1100 | * in null mappings (currently treated as "copy-on-access") | |
1101 | */ | |
1102 | static int remap_pte_range(struct mm_struct *mm, pmd_t *pmd, | |
1103 | unsigned long addr, unsigned long end, | |
1104 | unsigned long pfn, pgprot_t prot) | |
1105 | { | |
1106 | pte_t *pte; | |
1107 | ||
1108 | pte = pte_alloc_map(mm, pmd, addr); | |
1109 | if (!pte) | |
1110 | return -ENOMEM; | |
1111 | do { | |
1112 | BUG_ON(!pte_none(*pte)); | |
1113 | if (!pfn_valid(pfn) || PageReserved(pfn_to_page(pfn))) | |
1114 | set_pte_at(mm, addr, pte, pfn_pte(pfn, prot)); | |
1115 | pfn++; | |
1116 | } while (pte++, addr += PAGE_SIZE, addr != end); | |
1117 | pte_unmap(pte - 1); | |
1118 | return 0; | |
1119 | } | |
1120 | ||
1121 | static inline int remap_pmd_range(struct mm_struct *mm, pud_t *pud, | |
1122 | unsigned long addr, unsigned long end, | |
1123 | unsigned long pfn, pgprot_t prot) | |
1124 | { | |
1125 | pmd_t *pmd; | |
1126 | unsigned long next; | |
1127 | ||
1128 | pfn -= addr >> PAGE_SHIFT; | |
1129 | pmd = pmd_alloc(mm, pud, addr); | |
1130 | if (!pmd) | |
1131 | return -ENOMEM; | |
1132 | do { | |
1133 | next = pmd_addr_end(addr, end); | |
1134 | if (remap_pte_range(mm, pmd, addr, next, | |
1135 | pfn + (addr >> PAGE_SHIFT), prot)) | |
1136 | return -ENOMEM; | |
1137 | } while (pmd++, addr = next, addr != end); | |
1138 | return 0; | |
1139 | } | |
1140 | ||
1141 | static inline int remap_pud_range(struct mm_struct *mm, pgd_t *pgd, | |
1142 | unsigned long addr, unsigned long end, | |
1143 | unsigned long pfn, pgprot_t prot) | |
1144 | { | |
1145 | pud_t *pud; | |
1146 | unsigned long next; | |
1147 | ||
1148 | pfn -= addr >> PAGE_SHIFT; | |
1149 | pud = pud_alloc(mm, pgd, addr); | |
1150 | if (!pud) | |
1151 | return -ENOMEM; | |
1152 | do { | |
1153 | next = pud_addr_end(addr, end); | |
1154 | if (remap_pmd_range(mm, pud, addr, next, | |
1155 | pfn + (addr >> PAGE_SHIFT), prot)) | |
1156 | return -ENOMEM; | |
1157 | } while (pud++, addr = next, addr != end); | |
1158 | return 0; | |
1159 | } | |
1160 | ||
1161 | /* Note: this is only safe if the mm semaphore is held when called. */ | |
1162 | int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, | |
1163 | unsigned long pfn, unsigned long size, pgprot_t prot) | |
1164 | { | |
1165 | pgd_t *pgd; | |
1166 | unsigned long next; | |
2d15cab8 | 1167 | unsigned long end = addr + PAGE_ALIGN(size); |
1da177e4 LT |
1168 | struct mm_struct *mm = vma->vm_mm; |
1169 | int err; | |
1170 | ||
1171 | /* | |
1172 | * Physically remapped pages are special. Tell the | |
1173 | * rest of the world about it: | |
1174 | * VM_IO tells people not to look at these pages | |
1175 | * (accesses can have side effects). | |
1176 | * VM_RESERVED tells swapout not to try to touch | |
1177 | * this region. | |
1178 | */ | |
1179 | vma->vm_flags |= VM_IO | VM_RESERVED; | |
1180 | ||
1181 | BUG_ON(addr >= end); | |
1182 | pfn -= addr >> PAGE_SHIFT; | |
1183 | pgd = pgd_offset(mm, addr); | |
1184 | flush_cache_range(vma, addr, end); | |
1185 | spin_lock(&mm->page_table_lock); | |
1186 | do { | |
1187 | next = pgd_addr_end(addr, end); | |
1188 | err = remap_pud_range(mm, pgd, addr, next, | |
1189 | pfn + (addr >> PAGE_SHIFT), prot); | |
1190 | if (err) | |
1191 | break; | |
1192 | } while (pgd++, addr = next, addr != end); | |
1193 | spin_unlock(&mm->page_table_lock); | |
1194 | return err; | |
1195 | } | |
1196 | EXPORT_SYMBOL(remap_pfn_range); | |
1197 | ||
1198 | /* | |
1199 | * Do pte_mkwrite, but only if the vma says VM_WRITE. We do this when | |
1200 | * servicing faults for write access. In the normal case, do always want | |
1201 | * pte_mkwrite. But get_user_pages can cause write faults for mappings | |
1202 | * that do not have writing enabled, when used by access_process_vm. | |
1203 | */ | |
1204 | static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) | |
1205 | { | |
1206 | if (likely(vma->vm_flags & VM_WRITE)) | |
1207 | pte = pte_mkwrite(pte); | |
1208 | return pte; | |
1209 | } | |
1210 | ||
1211 | /* | |
1212 | * We hold the mm semaphore for reading and vma->vm_mm->page_table_lock | |
1213 | */ | |
1214 | static inline void break_cow(struct vm_area_struct * vma, struct page * new_page, unsigned long address, | |
1215 | pte_t *page_table) | |
1216 | { | |
1217 | pte_t entry; | |
1218 | ||
1219 | entry = maybe_mkwrite(pte_mkdirty(mk_pte(new_page, vma->vm_page_prot)), | |
1220 | vma); | |
1221 | ptep_establish(vma, address, page_table, entry); | |
1222 | update_mmu_cache(vma, address, entry); | |
1223 | lazy_mmu_prot_update(entry); | |
1224 | } | |
1225 | ||
1226 | /* | |
1227 | * This routine handles present pages, when users try to write | |
1228 | * to a shared page. It is done by copying the page to a new address | |
1229 | * and decrementing the shared-page counter for the old page. | |
1230 | * | |
1231 | * Goto-purists beware: the only reason for goto's here is that it results | |
1232 | * in better assembly code.. The "default" path will see no jumps at all. | |
1233 | * | |
1234 | * Note that this routine assumes that the protection checks have been | |
1235 | * done by the caller (the low-level page fault routine in most cases). | |
1236 | * Thus we can safely just mark it writable once we've done any necessary | |
1237 | * COW. | |
1238 | * | |
1239 | * We also mark the page dirty at this point even though the page will | |
1240 | * change only once the write actually happens. This avoids a few races, | |
1241 | * and potentially makes it more efficient. | |
1242 | * | |
1243 | * We hold the mm semaphore and the page_table_lock on entry and exit | |
1244 | * with the page_table_lock released. | |
1245 | */ | |
1246 | static int do_wp_page(struct mm_struct *mm, struct vm_area_struct * vma, | |
1247 | unsigned long address, pte_t *page_table, pmd_t *pmd, pte_t pte) | |
1248 | { | |
1249 | struct page *old_page, *new_page; | |
1250 | unsigned long pfn = pte_pfn(pte); | |
1251 | pte_t entry; | |
f33ea7f4 | 1252 | int ret; |
1da177e4 LT |
1253 | |
1254 | if (unlikely(!pfn_valid(pfn))) { | |
1255 | /* | |
1256 | * This should really halt the system so it can be debugged or | |
1257 | * at least the kernel stops what it's doing before it corrupts | |
1258 | * data, but for the moment just pretend this is OOM. | |
1259 | */ | |
1260 | pte_unmap(page_table); | |
1261 | printk(KERN_ERR "do_wp_page: bogus page at address %08lx\n", | |
1262 | address); | |
1263 | spin_unlock(&mm->page_table_lock); | |
1264 | return VM_FAULT_OOM; | |
1265 | } | |
1266 | old_page = pfn_to_page(pfn); | |
1267 | ||
d296e9cd | 1268 | if (PageAnon(old_page) && !TestSetPageLocked(old_page)) { |
1da177e4 LT |
1269 | int reuse = can_share_swap_page(old_page); |
1270 | unlock_page(old_page); | |
1271 | if (reuse) { | |
1272 | flush_cache_page(vma, address, pfn); | |
1273 | entry = maybe_mkwrite(pte_mkyoung(pte_mkdirty(pte)), | |
1274 | vma); | |
1275 | ptep_set_access_flags(vma, address, page_table, entry, 1); | |
1276 | update_mmu_cache(vma, address, entry); | |
1277 | lazy_mmu_prot_update(entry); | |
1278 | pte_unmap(page_table); | |
1279 | spin_unlock(&mm->page_table_lock); | |
f33ea7f4 | 1280 | return VM_FAULT_MINOR|VM_FAULT_WRITE; |
1da177e4 LT |
1281 | } |
1282 | } | |
1283 | pte_unmap(page_table); | |
1284 | ||
1285 | /* | |
1286 | * Ok, we need to copy. Oh, well.. | |
1287 | */ | |
1288 | if (!PageReserved(old_page)) | |
1289 | page_cache_get(old_page); | |
1290 | spin_unlock(&mm->page_table_lock); | |
1291 | ||
1292 | if (unlikely(anon_vma_prepare(vma))) | |
1293 | goto no_new_page; | |
1294 | if (old_page == ZERO_PAGE(address)) { | |
1295 | new_page = alloc_zeroed_user_highpage(vma, address); | |
1296 | if (!new_page) | |
1297 | goto no_new_page; | |
1298 | } else { | |
1299 | new_page = alloc_page_vma(GFP_HIGHUSER, vma, address); | |
1300 | if (!new_page) | |
1301 | goto no_new_page; | |
1302 | copy_user_highpage(new_page, old_page, address); | |
1303 | } | |
1304 | /* | |
1305 | * Re-check the pte - we dropped the lock | |
1306 | */ | |
f33ea7f4 | 1307 | ret = VM_FAULT_MINOR; |
1da177e4 LT |
1308 | spin_lock(&mm->page_table_lock); |
1309 | page_table = pte_offset_map(pmd, address); | |
1310 | if (likely(pte_same(*page_table, pte))) { | |
1311 | if (PageAnon(old_page)) | |
1312 | dec_mm_counter(mm, anon_rss); | |
1313 | if (PageReserved(old_page)) | |
1314 | inc_mm_counter(mm, rss); | |
1315 | else | |
1316 | page_remove_rmap(old_page); | |
1317 | flush_cache_page(vma, address, pfn); | |
1318 | break_cow(vma, new_page, address, page_table); | |
1319 | lru_cache_add_active(new_page); | |
1320 | page_add_anon_rmap(new_page, vma, address); | |
1321 | ||
1322 | /* Free the old page.. */ | |
1323 | new_page = old_page; | |
f33ea7f4 | 1324 | ret |= VM_FAULT_WRITE; |
1da177e4 LT |
1325 | } |
1326 | pte_unmap(page_table); | |
1327 | page_cache_release(new_page); | |
1328 | page_cache_release(old_page); | |
1329 | spin_unlock(&mm->page_table_lock); | |
f33ea7f4 | 1330 | return ret; |
1da177e4 LT |
1331 | |
1332 | no_new_page: | |
1333 | page_cache_release(old_page); | |
1334 | return VM_FAULT_OOM; | |
1335 | } | |
1336 | ||
1337 | /* | |
1338 | * Helper functions for unmap_mapping_range(). | |
1339 | * | |
1340 | * __ Notes on dropping i_mmap_lock to reduce latency while unmapping __ | |
1341 | * | |
1342 | * We have to restart searching the prio_tree whenever we drop the lock, | |
1343 | * since the iterator is only valid while the lock is held, and anyway | |
1344 | * a later vma might be split and reinserted earlier while lock dropped. | |
1345 | * | |
1346 | * The list of nonlinear vmas could be handled more efficiently, using | |
1347 | * a placeholder, but handle it in the same way until a need is shown. | |
1348 | * It is important to search the prio_tree before nonlinear list: a vma | |
1349 | * may become nonlinear and be shifted from prio_tree to nonlinear list | |
1350 | * while the lock is dropped; but never shifted from list to prio_tree. | |
1351 | * | |
1352 | * In order to make forward progress despite restarting the search, | |
1353 | * vm_truncate_count is used to mark a vma as now dealt with, so we can | |
1354 | * quickly skip it next time around. Since the prio_tree search only | |
1355 | * shows us those vmas affected by unmapping the range in question, we | |
1356 | * can't efficiently keep all vmas in step with mapping->truncate_count: | |
1357 | * so instead reset them all whenever it wraps back to 0 (then go to 1). | |
1358 | * mapping->truncate_count and vma->vm_truncate_count are protected by | |
1359 | * i_mmap_lock. | |
1360 | * | |
1361 | * In order to make forward progress despite repeatedly restarting some | |
ee39b37b | 1362 | * large vma, note the restart_addr from unmap_vmas when it breaks out: |
1da177e4 LT |
1363 | * and restart from that address when we reach that vma again. It might |
1364 | * have been split or merged, shrunk or extended, but never shifted: so | |
1365 | * restart_addr remains valid so long as it remains in the vma's range. | |
1366 | * unmap_mapping_range forces truncate_count to leap over page-aligned | |
1367 | * values so we can save vma's restart_addr in its truncate_count field. | |
1368 | */ | |
1369 | #define is_restart_addr(truncate_count) (!((truncate_count) & ~PAGE_MASK)) | |
1370 | ||
1371 | static void reset_vma_truncate_counts(struct address_space *mapping) | |
1372 | { | |
1373 | struct vm_area_struct *vma; | |
1374 | struct prio_tree_iter iter; | |
1375 | ||
1376 | vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, 0, ULONG_MAX) | |
1377 | vma->vm_truncate_count = 0; | |
1378 | list_for_each_entry(vma, &mapping->i_mmap_nonlinear, shared.vm_set.list) | |
1379 | vma->vm_truncate_count = 0; | |
1380 | } | |
1381 | ||
1382 | static int unmap_mapping_range_vma(struct vm_area_struct *vma, | |
1383 | unsigned long start_addr, unsigned long end_addr, | |
1384 | struct zap_details *details) | |
1385 | { | |
1386 | unsigned long restart_addr; | |
1387 | int need_break; | |
1388 | ||
1389 | again: | |
1390 | restart_addr = vma->vm_truncate_count; | |
1391 | if (is_restart_addr(restart_addr) && start_addr < restart_addr) { | |
1392 | start_addr = restart_addr; | |
1393 | if (start_addr >= end_addr) { | |
1394 | /* Top of vma has been split off since last time */ | |
1395 | vma->vm_truncate_count = details->truncate_count; | |
1396 | return 0; | |
1397 | } | |
1398 | } | |
1399 | ||
ee39b37b HD |
1400 | restart_addr = zap_page_range(vma, start_addr, |
1401 | end_addr - start_addr, details); | |
1da177e4 LT |
1402 | |
1403 | /* | |
1404 | * We cannot rely on the break test in unmap_vmas: | |
1405 | * on the one hand, we don't want to restart our loop | |
1406 | * just because that broke out for the page_table_lock; | |
1407 | * on the other hand, it does no test when vma is small. | |
1408 | */ | |
1409 | need_break = need_resched() || | |
1410 | need_lockbreak(details->i_mmap_lock); | |
1411 | ||
ee39b37b | 1412 | if (restart_addr >= end_addr) { |
1da177e4 LT |
1413 | /* We have now completed this vma: mark it so */ |
1414 | vma->vm_truncate_count = details->truncate_count; | |
1415 | if (!need_break) | |
1416 | return 0; | |
1417 | } else { | |
1418 | /* Note restart_addr in vma's truncate_count field */ | |
ee39b37b | 1419 | vma->vm_truncate_count = restart_addr; |
1da177e4 LT |
1420 | if (!need_break) |
1421 | goto again; | |
1422 | } | |
1423 | ||
1424 | spin_unlock(details->i_mmap_lock); | |
1425 | cond_resched(); | |
1426 | spin_lock(details->i_mmap_lock); | |
1427 | return -EINTR; | |
1428 | } | |
1429 | ||
1430 | static inline void unmap_mapping_range_tree(struct prio_tree_root *root, | |
1431 | struct zap_details *details) | |
1432 | { | |
1433 | struct vm_area_struct *vma; | |
1434 | struct prio_tree_iter iter; | |
1435 | pgoff_t vba, vea, zba, zea; | |
1436 | ||
1437 | restart: | |
1438 | vma_prio_tree_foreach(vma, &iter, root, | |
1439 | details->first_index, details->last_index) { | |
1440 | /* Skip quickly over those we have already dealt with */ | |
1441 | if (vma->vm_truncate_count == details->truncate_count) | |
1442 | continue; | |
1443 | ||
1444 | vba = vma->vm_pgoff; | |
1445 | vea = vba + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) - 1; | |
1446 | /* Assume for now that PAGE_CACHE_SHIFT == PAGE_SHIFT */ | |
1447 | zba = details->first_index; | |
1448 | if (zba < vba) | |
1449 | zba = vba; | |
1450 | zea = details->last_index; | |
1451 | if (zea > vea) | |
1452 | zea = vea; | |
1453 | ||
1454 | if (unmap_mapping_range_vma(vma, | |
1455 | ((zba - vba) << PAGE_SHIFT) + vma->vm_start, | |
1456 | ((zea - vba + 1) << PAGE_SHIFT) + vma->vm_start, | |
1457 | details) < 0) | |
1458 | goto restart; | |
1459 | } | |
1460 | } | |
1461 | ||
1462 | static inline void unmap_mapping_range_list(struct list_head *head, | |
1463 | struct zap_details *details) | |
1464 | { | |
1465 | struct vm_area_struct *vma; | |
1466 | ||
1467 | /* | |
1468 | * In nonlinear VMAs there is no correspondence between virtual address | |
1469 | * offset and file offset. So we must perform an exhaustive search | |
1470 | * across *all* the pages in each nonlinear VMA, not just the pages | |
1471 | * whose virtual address lies outside the file truncation point. | |
1472 | */ | |
1473 | restart: | |
1474 | list_for_each_entry(vma, head, shared.vm_set.list) { | |
1475 | /* Skip quickly over those we have already dealt with */ | |
1476 | if (vma->vm_truncate_count == details->truncate_count) | |
1477 | continue; | |
1478 | details->nonlinear_vma = vma; | |
1479 | if (unmap_mapping_range_vma(vma, vma->vm_start, | |
1480 | vma->vm_end, details) < 0) | |
1481 | goto restart; | |
1482 | } | |
1483 | } | |
1484 | ||
1485 | /** | |
1486 | * unmap_mapping_range - unmap the portion of all mmaps | |
1487 | * in the specified address_space corresponding to the specified | |
1488 | * page range in the underlying file. | |
3d41088f | 1489 | * @mapping: the address space containing mmaps to be unmapped. |
1da177e4 LT |
1490 | * @holebegin: byte in first page to unmap, relative to the start of |
1491 | * the underlying file. This will be rounded down to a PAGE_SIZE | |
1492 | * boundary. Note that this is different from vmtruncate(), which | |
1493 | * must keep the partial page. In contrast, we must get rid of | |
1494 | * partial pages. | |
1495 | * @holelen: size of prospective hole in bytes. This will be rounded | |
1496 | * up to a PAGE_SIZE boundary. A holelen of zero truncates to the | |
1497 | * end of the file. | |
1498 | * @even_cows: 1 when truncating a file, unmap even private COWed pages; | |
1499 | * but 0 when invalidating pagecache, don't throw away private data. | |
1500 | */ | |
1501 | void unmap_mapping_range(struct address_space *mapping, | |
1502 | loff_t const holebegin, loff_t const holelen, int even_cows) | |
1503 | { | |
1504 | struct zap_details details; | |
1505 | pgoff_t hba = holebegin >> PAGE_SHIFT; | |
1506 | pgoff_t hlen = (holelen + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
1507 | ||
1508 | /* Check for overflow. */ | |
1509 | if (sizeof(holelen) > sizeof(hlen)) { | |
1510 | long long holeend = | |
1511 | (holebegin + holelen + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
1512 | if (holeend & ~(long long)ULONG_MAX) | |
1513 | hlen = ULONG_MAX - hba + 1; | |
1514 | } | |
1515 | ||
1516 | details.check_mapping = even_cows? NULL: mapping; | |
1517 | details.nonlinear_vma = NULL; | |
1518 | details.first_index = hba; | |
1519 | details.last_index = hba + hlen - 1; | |
1520 | if (details.last_index < details.first_index) | |
1521 | details.last_index = ULONG_MAX; | |
1522 | details.i_mmap_lock = &mapping->i_mmap_lock; | |
1523 | ||
1524 | spin_lock(&mapping->i_mmap_lock); | |
1525 | ||
1526 | /* serialize i_size write against truncate_count write */ | |
1527 | smp_wmb(); | |
1528 | /* Protect against page faults, and endless unmapping loops */ | |
1529 | mapping->truncate_count++; | |
1530 | /* | |
1531 | * For archs where spin_lock has inclusive semantics like ia64 | |
1532 | * this smp_mb() will prevent to read pagetable contents | |
1533 | * before the truncate_count increment is visible to | |
1534 | * other cpus. | |
1535 | */ | |
1536 | smp_mb(); | |
1537 | if (unlikely(is_restart_addr(mapping->truncate_count))) { | |
1538 | if (mapping->truncate_count == 0) | |
1539 | reset_vma_truncate_counts(mapping); | |
1540 | mapping->truncate_count++; | |
1541 | } | |
1542 | details.truncate_count = mapping->truncate_count; | |
1543 | ||
1544 | if (unlikely(!prio_tree_empty(&mapping->i_mmap))) | |
1545 | unmap_mapping_range_tree(&mapping->i_mmap, &details); | |
1546 | if (unlikely(!list_empty(&mapping->i_mmap_nonlinear))) | |
1547 | unmap_mapping_range_list(&mapping->i_mmap_nonlinear, &details); | |
1548 | spin_unlock(&mapping->i_mmap_lock); | |
1549 | } | |
1550 | EXPORT_SYMBOL(unmap_mapping_range); | |
1551 | ||
1552 | /* | |
1553 | * Handle all mappings that got truncated by a "truncate()" | |
1554 | * system call. | |
1555 | * | |
1556 | * NOTE! We have to be ready to update the memory sharing | |
1557 | * between the file and the memory map for a potential last | |
1558 | * incomplete page. Ugly, but necessary. | |
1559 | */ | |
1560 | int vmtruncate(struct inode * inode, loff_t offset) | |
1561 | { | |
1562 | struct address_space *mapping = inode->i_mapping; | |
1563 | unsigned long limit; | |
1564 | ||
1565 | if (inode->i_size < offset) | |
1566 | goto do_expand; | |
1567 | /* | |
1568 | * truncation of in-use swapfiles is disallowed - it would cause | |
1569 | * subsequent swapout to scribble on the now-freed blocks. | |
1570 | */ | |
1571 | if (IS_SWAPFILE(inode)) | |
1572 | goto out_busy; | |
1573 | i_size_write(inode, offset); | |
1574 | unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1); | |
1575 | truncate_inode_pages(mapping, offset); | |
1576 | goto out_truncate; | |
1577 | ||
1578 | do_expand: | |
1579 | limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur; | |
1580 | if (limit != RLIM_INFINITY && offset > limit) | |
1581 | goto out_sig; | |
1582 | if (offset > inode->i_sb->s_maxbytes) | |
1583 | goto out_big; | |
1584 | i_size_write(inode, offset); | |
1585 | ||
1586 | out_truncate: | |
1587 | if (inode->i_op && inode->i_op->truncate) | |
1588 | inode->i_op->truncate(inode); | |
1589 | return 0; | |
1590 | out_sig: | |
1591 | send_sig(SIGXFSZ, current, 0); | |
1592 | out_big: | |
1593 | return -EFBIG; | |
1594 | out_busy: | |
1595 | return -ETXTBSY; | |
1596 | } | |
1597 | ||
1598 | EXPORT_SYMBOL(vmtruncate); | |
1599 | ||
1600 | /* | |
1601 | * Primitive swap readahead code. We simply read an aligned block of | |
1602 | * (1 << page_cluster) entries in the swap area. This method is chosen | |
1603 | * because it doesn't cost us any seek time. We also make sure to queue | |
1604 | * the 'original' request together with the readahead ones... | |
1605 | * | |
1606 | * This has been extended to use the NUMA policies from the mm triggering | |
1607 | * the readahead. | |
1608 | * | |
1609 | * Caller must hold down_read on the vma->vm_mm if vma is not NULL. | |
1610 | */ | |
1611 | void swapin_readahead(swp_entry_t entry, unsigned long addr,struct vm_area_struct *vma) | |
1612 | { | |
1613 | #ifdef CONFIG_NUMA | |
1614 | struct vm_area_struct *next_vma = vma ? vma->vm_next : NULL; | |
1615 | #endif | |
1616 | int i, num; | |
1617 | struct page *new_page; | |
1618 | unsigned long offset; | |
1619 | ||
1620 | /* | |
1621 | * Get the number of handles we should do readahead io to. | |
1622 | */ | |
1623 | num = valid_swaphandles(entry, &offset); | |
1624 | for (i = 0; i < num; offset++, i++) { | |
1625 | /* Ok, do the async read-ahead now */ | |
1626 | new_page = read_swap_cache_async(swp_entry(swp_type(entry), | |
1627 | offset), vma, addr); | |
1628 | if (!new_page) | |
1629 | break; | |
1630 | page_cache_release(new_page); | |
1631 | #ifdef CONFIG_NUMA | |
1632 | /* | |
1633 | * Find the next applicable VMA for the NUMA policy. | |
1634 | */ | |
1635 | addr += PAGE_SIZE; | |
1636 | if (addr == 0) | |
1637 | vma = NULL; | |
1638 | if (vma) { | |
1639 | if (addr >= vma->vm_end) { | |
1640 | vma = next_vma; | |
1641 | next_vma = vma ? vma->vm_next : NULL; | |
1642 | } | |
1643 | if (vma && addr < vma->vm_start) | |
1644 | vma = NULL; | |
1645 | } else { | |
1646 | if (next_vma && addr >= next_vma->vm_start) { | |
1647 | vma = next_vma; | |
1648 | next_vma = vma->vm_next; | |
1649 | } | |
1650 | } | |
1651 | #endif | |
1652 | } | |
1653 | lru_add_drain(); /* Push any new pages onto the LRU now */ | |
1654 | } | |
1655 | ||
1656 | /* | |
1657 | * We hold the mm semaphore and the page_table_lock on entry and | |
1658 | * should release the pagetable lock on exit.. | |
1659 | */ | |
1660 | static int do_swap_page(struct mm_struct * mm, | |
1661 | struct vm_area_struct * vma, unsigned long address, | |
1662 | pte_t *page_table, pmd_t *pmd, pte_t orig_pte, int write_access) | |
1663 | { | |
1664 | struct page *page; | |
1665 | swp_entry_t entry = pte_to_swp_entry(orig_pte); | |
1666 | pte_t pte; | |
1667 | int ret = VM_FAULT_MINOR; | |
1668 | ||
1669 | pte_unmap(page_table); | |
1670 | spin_unlock(&mm->page_table_lock); | |
1671 | page = lookup_swap_cache(entry); | |
1672 | if (!page) { | |
1673 | swapin_readahead(entry, address, vma); | |
1674 | page = read_swap_cache_async(entry, vma, address); | |
1675 | if (!page) { | |
1676 | /* | |
1677 | * Back out if somebody else faulted in this pte while | |
1678 | * we released the page table lock. | |
1679 | */ | |
1680 | spin_lock(&mm->page_table_lock); | |
1681 | page_table = pte_offset_map(pmd, address); | |
1682 | if (likely(pte_same(*page_table, orig_pte))) | |
1683 | ret = VM_FAULT_OOM; | |
1684 | else | |
1685 | ret = VM_FAULT_MINOR; | |
1686 | pte_unmap(page_table); | |
1687 | spin_unlock(&mm->page_table_lock); | |
1688 | goto out; | |
1689 | } | |
1690 | ||
1691 | /* Had to read the page from swap area: Major fault */ | |
1692 | ret = VM_FAULT_MAJOR; | |
1693 | inc_page_state(pgmajfault); | |
1694 | grab_swap_token(); | |
1695 | } | |
1696 | ||
1697 | mark_page_accessed(page); | |
1698 | lock_page(page); | |
1699 | ||
1700 | /* | |
1701 | * Back out if somebody else faulted in this pte while we | |
1702 | * released the page table lock. | |
1703 | */ | |
1704 | spin_lock(&mm->page_table_lock); | |
1705 | page_table = pte_offset_map(pmd, address); | |
1706 | if (unlikely(!pte_same(*page_table, orig_pte))) { | |
1da177e4 | 1707 | ret = VM_FAULT_MINOR; |
b8107480 KK |
1708 | goto out_nomap; |
1709 | } | |
1710 | ||
1711 | if (unlikely(!PageUptodate(page))) { | |
1712 | ret = VM_FAULT_SIGBUS; | |
1713 | goto out_nomap; | |
1da177e4 LT |
1714 | } |
1715 | ||
1716 | /* The page isn't present yet, go ahead with the fault. */ | |
1da177e4 LT |
1717 | |
1718 | inc_mm_counter(mm, rss); | |
1719 | pte = mk_pte(page, vma->vm_page_prot); | |
1720 | if (write_access && can_share_swap_page(page)) { | |
1721 | pte = maybe_mkwrite(pte_mkdirty(pte), vma); | |
1722 | write_access = 0; | |
1723 | } | |
1da177e4 LT |
1724 | |
1725 | flush_icache_page(vma, page); | |
1726 | set_pte_at(mm, address, page_table, pte); | |
1727 | page_add_anon_rmap(page, vma, address); | |
1728 | ||
c475a8ab HD |
1729 | swap_free(entry); |
1730 | if (vm_swap_full()) | |
1731 | remove_exclusive_swap_page(page); | |
1732 | unlock_page(page); | |
1733 | ||
1da177e4 LT |
1734 | if (write_access) { |
1735 | if (do_wp_page(mm, vma, address, | |
1736 | page_table, pmd, pte) == VM_FAULT_OOM) | |
1737 | ret = VM_FAULT_OOM; | |
1738 | goto out; | |
1739 | } | |
1740 | ||
1741 | /* No need to invalidate - it was non-present before */ | |
1742 | update_mmu_cache(vma, address, pte); | |
1743 | lazy_mmu_prot_update(pte); | |
1744 | pte_unmap(page_table); | |
1745 | spin_unlock(&mm->page_table_lock); | |
1746 | out: | |
1747 | return ret; | |
b8107480 KK |
1748 | out_nomap: |
1749 | pte_unmap(page_table); | |
1750 | spin_unlock(&mm->page_table_lock); | |
1751 | unlock_page(page); | |
1752 | page_cache_release(page); | |
1753 | goto out; | |
1da177e4 LT |
1754 | } |
1755 | ||
1756 | /* | |
1757 | * We are called with the MM semaphore and page_table_lock | |
1758 | * spinlock held to protect against concurrent faults in | |
1759 | * multithreaded programs. | |
1760 | */ | |
1761 | static int | |
1762 | do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, | |
1763 | pte_t *page_table, pmd_t *pmd, int write_access, | |
1764 | unsigned long addr) | |
1765 | { | |
1766 | pte_t entry; | |
1767 | struct page * page = ZERO_PAGE(addr); | |
1768 | ||
1769 | /* Read-only mapping of ZERO_PAGE. */ | |
1770 | entry = pte_wrprotect(mk_pte(ZERO_PAGE(addr), vma->vm_page_prot)); | |
1771 | ||
1772 | /* ..except if it's a write access */ | |
1773 | if (write_access) { | |
1774 | /* Allocate our own private page. */ | |
1775 | pte_unmap(page_table); | |
1776 | spin_unlock(&mm->page_table_lock); | |
1777 | ||
1778 | if (unlikely(anon_vma_prepare(vma))) | |
1779 | goto no_mem; | |
1780 | page = alloc_zeroed_user_highpage(vma, addr); | |
1781 | if (!page) | |
1782 | goto no_mem; | |
1783 | ||
1784 | spin_lock(&mm->page_table_lock); | |
1785 | page_table = pte_offset_map(pmd, addr); | |
1786 | ||
1787 | if (!pte_none(*page_table)) { | |
1788 | pte_unmap(page_table); | |
1789 | page_cache_release(page); | |
1790 | spin_unlock(&mm->page_table_lock); | |
1791 | goto out; | |
1792 | } | |
1793 | inc_mm_counter(mm, rss); | |
1794 | entry = maybe_mkwrite(pte_mkdirty(mk_pte(page, | |
1795 | vma->vm_page_prot)), | |
1796 | vma); | |
1797 | lru_cache_add_active(page); | |
1798 | SetPageReferenced(page); | |
1799 | page_add_anon_rmap(page, vma, addr); | |
1800 | } | |
1801 | ||
1802 | set_pte_at(mm, addr, page_table, entry); | |
1803 | pte_unmap(page_table); | |
1804 | ||
1805 | /* No need to invalidate - it was non-present before */ | |
1806 | update_mmu_cache(vma, addr, entry); | |
1807 | lazy_mmu_prot_update(entry); | |
1808 | spin_unlock(&mm->page_table_lock); | |
1809 | out: | |
1810 | return VM_FAULT_MINOR; | |
1811 | no_mem: | |
1812 | return VM_FAULT_OOM; | |
1813 | } | |
1814 | ||
1815 | /* | |
1816 | * do_no_page() tries to create a new page mapping. It aggressively | |
1817 | * tries to share with existing pages, but makes a separate copy if | |
1818 | * the "write_access" parameter is true in order to avoid the next | |
1819 | * page fault. | |
1820 | * | |
1821 | * As this is called only for pages that do not currently exist, we | |
1822 | * do not need to flush old virtual caches or the TLB. | |
1823 | * | |
1824 | * This is called with the MM semaphore held and the page table | |
1825 | * spinlock held. Exit with the spinlock released. | |
1826 | */ | |
1827 | static int | |
1828 | do_no_page(struct mm_struct *mm, struct vm_area_struct *vma, | |
1829 | unsigned long address, int write_access, pte_t *page_table, pmd_t *pmd) | |
1830 | { | |
1831 | struct page * new_page; | |
1832 | struct address_space *mapping = NULL; | |
1833 | pte_t entry; | |
1834 | unsigned int sequence = 0; | |
1835 | int ret = VM_FAULT_MINOR; | |
1836 | int anon = 0; | |
1837 | ||
1838 | if (!vma->vm_ops || !vma->vm_ops->nopage) | |
1839 | return do_anonymous_page(mm, vma, page_table, | |
1840 | pmd, write_access, address); | |
1841 | pte_unmap(page_table); | |
1842 | spin_unlock(&mm->page_table_lock); | |
1843 | ||
1844 | if (vma->vm_file) { | |
1845 | mapping = vma->vm_file->f_mapping; | |
1846 | sequence = mapping->truncate_count; | |
1847 | smp_rmb(); /* serializes i_size against truncate_count */ | |
1848 | } | |
1849 | retry: | |
1850 | cond_resched(); | |
1851 | new_page = vma->vm_ops->nopage(vma, address & PAGE_MASK, &ret); | |
1852 | /* | |
1853 | * No smp_rmb is needed here as long as there's a full | |
1854 | * spin_lock/unlock sequence inside the ->nopage callback | |
1855 | * (for the pagecache lookup) that acts as an implicit | |
1856 | * smp_mb() and prevents the i_size read to happen | |
1857 | * after the next truncate_count read. | |
1858 | */ | |
1859 | ||
1860 | /* no page was available -- either SIGBUS or OOM */ | |
1861 | if (new_page == NOPAGE_SIGBUS) | |
1862 | return VM_FAULT_SIGBUS; | |
1863 | if (new_page == NOPAGE_OOM) | |
1864 | return VM_FAULT_OOM; | |
1865 | ||
1866 | /* | |
1867 | * Should we do an early C-O-W break? | |
1868 | */ | |
1869 | if (write_access && !(vma->vm_flags & VM_SHARED)) { | |
1870 | struct page *page; | |
1871 | ||
1872 | if (unlikely(anon_vma_prepare(vma))) | |
1873 | goto oom; | |
1874 | page = alloc_page_vma(GFP_HIGHUSER, vma, address); | |
1875 | if (!page) | |
1876 | goto oom; | |
1877 | copy_user_highpage(page, new_page, address); | |
1878 | page_cache_release(new_page); | |
1879 | new_page = page; | |
1880 | anon = 1; | |
1881 | } | |
1882 | ||
1883 | spin_lock(&mm->page_table_lock); | |
1884 | /* | |
1885 | * For a file-backed vma, someone could have truncated or otherwise | |
1886 | * invalidated this page. If unmap_mapping_range got called, | |
1887 | * retry getting the page. | |
1888 | */ | |
1889 | if (mapping && unlikely(sequence != mapping->truncate_count)) { | |
1890 | sequence = mapping->truncate_count; | |
1891 | spin_unlock(&mm->page_table_lock); | |
1892 | page_cache_release(new_page); | |
1893 | goto retry; | |
1894 | } | |
1895 | page_table = pte_offset_map(pmd, address); | |
1896 | ||
1897 | /* | |
1898 | * This silly early PAGE_DIRTY setting removes a race | |
1899 | * due to the bad i386 page protection. But it's valid | |
1900 | * for other architectures too. | |
1901 | * | |
1902 | * Note that if write_access is true, we either now have | |
1903 | * an exclusive copy of the page, or this is a shared mapping, | |
1904 | * so we can make it writable and dirty to avoid having to | |
1905 | * handle that later. | |
1906 | */ | |
1907 | /* Only go through if we didn't race with anybody else... */ | |
1908 | if (pte_none(*page_table)) { | |
1909 | if (!PageReserved(new_page)) | |
1910 | inc_mm_counter(mm, rss); | |
1911 | ||
1912 | flush_icache_page(vma, new_page); | |
1913 | entry = mk_pte(new_page, vma->vm_page_prot); | |
1914 | if (write_access) | |
1915 | entry = maybe_mkwrite(pte_mkdirty(entry), vma); | |
1916 | set_pte_at(mm, address, page_table, entry); | |
1917 | if (anon) { | |
1918 | lru_cache_add_active(new_page); | |
1919 | page_add_anon_rmap(new_page, vma, address); | |
1920 | } else | |
1921 | page_add_file_rmap(new_page); | |
1922 | pte_unmap(page_table); | |
1923 | } else { | |
1924 | /* One of our sibling threads was faster, back out. */ | |
1925 | pte_unmap(page_table); | |
1926 | page_cache_release(new_page); | |
1927 | spin_unlock(&mm->page_table_lock); | |
1928 | goto out; | |
1929 | } | |
1930 | ||
1931 | /* no need to invalidate: a not-present page shouldn't be cached */ | |
1932 | update_mmu_cache(vma, address, entry); | |
1933 | lazy_mmu_prot_update(entry); | |
1934 | spin_unlock(&mm->page_table_lock); | |
1935 | out: | |
1936 | return ret; | |
1937 | oom: | |
1938 | page_cache_release(new_page); | |
1939 | ret = VM_FAULT_OOM; | |
1940 | goto out; | |
1941 | } | |
1942 | ||
1943 | /* | |
1944 | * Fault of a previously existing named mapping. Repopulate the pte | |
1945 | * from the encoded file_pte if possible. This enables swappable | |
1946 | * nonlinear vmas. | |
1947 | */ | |
1948 | static int do_file_page(struct mm_struct * mm, struct vm_area_struct * vma, | |
1949 | unsigned long address, int write_access, pte_t *pte, pmd_t *pmd) | |
1950 | { | |
1951 | unsigned long pgoff; | |
1952 | int err; | |
1953 | ||
1954 | BUG_ON(!vma->vm_ops || !vma->vm_ops->nopage); | |
1955 | /* | |
1956 | * Fall back to the linear mapping if the fs does not support | |
1957 | * ->populate: | |
1958 | */ | |
4944e76d | 1959 | if (!vma->vm_ops->populate || |
1da177e4 LT |
1960 | (write_access && !(vma->vm_flags & VM_SHARED))) { |
1961 | pte_clear(mm, address, pte); | |
1962 | return do_no_page(mm, vma, address, write_access, pte, pmd); | |
1963 | } | |
1964 | ||
1965 | pgoff = pte_to_pgoff(*pte); | |
1966 | ||
1967 | pte_unmap(pte); | |
1968 | spin_unlock(&mm->page_table_lock); | |
1969 | ||
1970 | err = vma->vm_ops->populate(vma, address & PAGE_MASK, PAGE_SIZE, vma->vm_page_prot, pgoff, 0); | |
1971 | if (err == -ENOMEM) | |
1972 | return VM_FAULT_OOM; | |
1973 | if (err) | |
1974 | return VM_FAULT_SIGBUS; | |
1975 | return VM_FAULT_MAJOR; | |
1976 | } | |
1977 | ||
1978 | /* | |
1979 | * These routines also need to handle stuff like marking pages dirty | |
1980 | * and/or accessed for architectures that don't do it in hardware (most | |
1981 | * RISC architectures). The early dirtying is also good on the i386. | |
1982 | * | |
1983 | * There is also a hook called "update_mmu_cache()" that architectures | |
1984 | * with external mmu caches can use to update those (ie the Sparc or | |
1985 | * PowerPC hashed page tables that act as extended TLBs). | |
1986 | * | |
1987 | * Note the "page_table_lock". It is to protect against kswapd removing | |
1988 | * pages from under us. Note that kswapd only ever _removes_ pages, never | |
1989 | * adds them. As such, once we have noticed that the page is not present, | |
1990 | * we can drop the lock early. | |
1991 | * | |
1992 | * The adding of pages is protected by the MM semaphore (which we hold), | |
1993 | * so we don't need to worry about a page being suddenly been added into | |
1994 | * our VM. | |
1995 | * | |
1996 | * We enter with the pagetable spinlock held, we are supposed to | |
1997 | * release it when done. | |
1998 | */ | |
1999 | static inline int handle_pte_fault(struct mm_struct *mm, | |
2000 | struct vm_area_struct * vma, unsigned long address, | |
2001 | int write_access, pte_t *pte, pmd_t *pmd) | |
2002 | { | |
2003 | pte_t entry; | |
2004 | ||
2005 | entry = *pte; | |
2006 | if (!pte_present(entry)) { | |
2007 | /* | |
2008 | * If it truly wasn't present, we know that kswapd | |
2009 | * and the PTE updates will not touch it later. So | |
2010 | * drop the lock. | |
2011 | */ | |
2012 | if (pte_none(entry)) | |
2013 | return do_no_page(mm, vma, address, write_access, pte, pmd); | |
2014 | if (pte_file(entry)) | |
2015 | return do_file_page(mm, vma, address, write_access, pte, pmd); | |
2016 | return do_swap_page(mm, vma, address, pte, pmd, entry, write_access); | |
2017 | } | |
2018 | ||
2019 | if (write_access) { | |
2020 | if (!pte_write(entry)) | |
2021 | return do_wp_page(mm, vma, address, pte, pmd, entry); | |
1da177e4 LT |
2022 | entry = pte_mkdirty(entry); |
2023 | } | |
2024 | entry = pte_mkyoung(entry); | |
2025 | ptep_set_access_flags(vma, address, pte, entry, write_access); | |
2026 | update_mmu_cache(vma, address, entry); | |
2027 | lazy_mmu_prot_update(entry); | |
2028 | pte_unmap(pte); | |
2029 | spin_unlock(&mm->page_table_lock); | |
2030 | return VM_FAULT_MINOR; | |
2031 | } | |
2032 | ||
2033 | /* | |
2034 | * By the time we get here, we already hold the mm semaphore | |
2035 | */ | |
f33ea7f4 | 2036 | int __handle_mm_fault(struct mm_struct *mm, struct vm_area_struct * vma, |
1da177e4 LT |
2037 | unsigned long address, int write_access) |
2038 | { | |
2039 | pgd_t *pgd; | |
2040 | pud_t *pud; | |
2041 | pmd_t *pmd; | |
2042 | pte_t *pte; | |
2043 | ||
2044 | __set_current_state(TASK_RUNNING); | |
2045 | ||
2046 | inc_page_state(pgfault); | |
2047 | ||
2048 | if (is_vm_hugetlb_page(vma)) | |
2049 | return VM_FAULT_SIGBUS; /* mapping truncation does this. */ | |
2050 | ||
2051 | /* | |
2052 | * We need the page table lock to synchronize with kswapd | |
2053 | * and the SMP-safe atomic PTE updates. | |
2054 | */ | |
2055 | pgd = pgd_offset(mm, address); | |
2056 | spin_lock(&mm->page_table_lock); | |
2057 | ||
2058 | pud = pud_alloc(mm, pgd, address); | |
2059 | if (!pud) | |
2060 | goto oom; | |
2061 | ||
2062 | pmd = pmd_alloc(mm, pud, address); | |
2063 | if (!pmd) | |
2064 | goto oom; | |
2065 | ||
2066 | pte = pte_alloc_map(mm, pmd, address); | |
2067 | if (!pte) | |
2068 | goto oom; | |
2069 | ||
2070 | return handle_pte_fault(mm, vma, address, write_access, pte, pmd); | |
2071 | ||
2072 | oom: | |
2073 | spin_unlock(&mm->page_table_lock); | |
2074 | return VM_FAULT_OOM; | |
2075 | } | |
2076 | ||
2077 | #ifndef __PAGETABLE_PUD_FOLDED | |
2078 | /* | |
2079 | * Allocate page upper directory. | |
2080 | * | |
2081 | * We've already handled the fast-path in-line, and we own the | |
2082 | * page table lock. | |
2083 | */ | |
2084 | pud_t fastcall *__pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address) | |
2085 | { | |
2086 | pud_t *new; | |
2087 | ||
2088 | spin_unlock(&mm->page_table_lock); | |
2089 | new = pud_alloc_one(mm, address); | |
2090 | spin_lock(&mm->page_table_lock); | |
2091 | if (!new) | |
2092 | return NULL; | |
2093 | ||
2094 | /* | |
2095 | * Because we dropped the lock, we should re-check the | |
2096 | * entry, as somebody else could have populated it.. | |
2097 | */ | |
2098 | if (pgd_present(*pgd)) { | |
2099 | pud_free(new); | |
2100 | goto out; | |
2101 | } | |
2102 | pgd_populate(mm, pgd, new); | |
2103 | out: | |
2104 | return pud_offset(pgd, address); | |
2105 | } | |
2106 | #endif /* __PAGETABLE_PUD_FOLDED */ | |
2107 | ||
2108 | #ifndef __PAGETABLE_PMD_FOLDED | |
2109 | /* | |
2110 | * Allocate page middle directory. | |
2111 | * | |
2112 | * We've already handled the fast-path in-line, and we own the | |
2113 | * page table lock. | |
2114 | */ | |
2115 | pmd_t fastcall *__pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address) | |
2116 | { | |
2117 | pmd_t *new; | |
2118 | ||
2119 | spin_unlock(&mm->page_table_lock); | |
2120 | new = pmd_alloc_one(mm, address); | |
2121 | spin_lock(&mm->page_table_lock); | |
2122 | if (!new) | |
2123 | return NULL; | |
2124 | ||
2125 | /* | |
2126 | * Because we dropped the lock, we should re-check the | |
2127 | * entry, as somebody else could have populated it.. | |
2128 | */ | |
2129 | #ifndef __ARCH_HAS_4LEVEL_HACK | |
2130 | if (pud_present(*pud)) { | |
2131 | pmd_free(new); | |
2132 | goto out; | |
2133 | } | |
2134 | pud_populate(mm, pud, new); | |
2135 | #else | |
2136 | if (pgd_present(*pud)) { | |
2137 | pmd_free(new); | |
2138 | goto out; | |
2139 | } | |
2140 | pgd_populate(mm, pud, new); | |
2141 | #endif /* __ARCH_HAS_4LEVEL_HACK */ | |
2142 | ||
2143 | out: | |
2144 | return pmd_offset(pud, address); | |
2145 | } | |
2146 | #endif /* __PAGETABLE_PMD_FOLDED */ | |
2147 | ||
2148 | int make_pages_present(unsigned long addr, unsigned long end) | |
2149 | { | |
2150 | int ret, len, write; | |
2151 | struct vm_area_struct * vma; | |
2152 | ||
2153 | vma = find_vma(current->mm, addr); | |
2154 | if (!vma) | |
2155 | return -1; | |
2156 | write = (vma->vm_flags & VM_WRITE) != 0; | |
2157 | if (addr >= end) | |
2158 | BUG(); | |
2159 | if (end > vma->vm_end) | |
2160 | BUG(); | |
2161 | len = (end+PAGE_SIZE-1)/PAGE_SIZE-addr/PAGE_SIZE; | |
2162 | ret = get_user_pages(current, current->mm, addr, | |
2163 | len, write, 0, NULL, NULL); | |
2164 | if (ret < 0) | |
2165 | return ret; | |
2166 | return ret == len ? 0 : -1; | |
2167 | } | |
2168 | ||
2169 | /* | |
2170 | * Map a vmalloc()-space virtual address to the physical page. | |
2171 | */ | |
2172 | struct page * vmalloc_to_page(void * vmalloc_addr) | |
2173 | { | |
2174 | unsigned long addr = (unsigned long) vmalloc_addr; | |
2175 | struct page *page = NULL; | |
2176 | pgd_t *pgd = pgd_offset_k(addr); | |
2177 | pud_t *pud; | |
2178 | pmd_t *pmd; | |
2179 | pte_t *ptep, pte; | |
2180 | ||
2181 | if (!pgd_none(*pgd)) { | |
2182 | pud = pud_offset(pgd, addr); | |
2183 | if (!pud_none(*pud)) { | |
2184 | pmd = pmd_offset(pud, addr); | |
2185 | if (!pmd_none(*pmd)) { | |
2186 | ptep = pte_offset_map(pmd, addr); | |
2187 | pte = *ptep; | |
2188 | if (pte_present(pte)) | |
2189 | page = pte_page(pte); | |
2190 | pte_unmap(ptep); | |
2191 | } | |
2192 | } | |
2193 | } | |
2194 | return page; | |
2195 | } | |
2196 | ||
2197 | EXPORT_SYMBOL(vmalloc_to_page); | |
2198 | ||
2199 | /* | |
2200 | * Map a vmalloc()-space virtual address to the physical page frame number. | |
2201 | */ | |
2202 | unsigned long vmalloc_to_pfn(void * vmalloc_addr) | |
2203 | { | |
2204 | return page_to_pfn(vmalloc_to_page(vmalloc_addr)); | |
2205 | } | |
2206 | ||
2207 | EXPORT_SYMBOL(vmalloc_to_pfn); | |
2208 | ||
2209 | /* | |
2210 | * update_mem_hiwater | |
2211 | * - update per process rss and vm high water data | |
2212 | */ | |
2213 | void update_mem_hiwater(struct task_struct *tsk) | |
2214 | { | |
2215 | if (tsk->mm) { | |
2216 | unsigned long rss = get_mm_counter(tsk->mm, rss); | |
2217 | ||
2218 | if (tsk->mm->hiwater_rss < rss) | |
2219 | tsk->mm->hiwater_rss = rss; | |
2220 | if (tsk->mm->hiwater_vm < tsk->mm->total_vm) | |
2221 | tsk->mm->hiwater_vm = tsk->mm->total_vm; | |
2222 | } | |
2223 | } | |
2224 | ||
2225 | #if !defined(__HAVE_ARCH_GATE_AREA) | |
2226 | ||
2227 | #if defined(AT_SYSINFO_EHDR) | |
2228 | struct vm_area_struct gate_vma; | |
2229 | ||
2230 | static int __init gate_vma_init(void) | |
2231 | { | |
2232 | gate_vma.vm_mm = NULL; | |
2233 | gate_vma.vm_start = FIXADDR_USER_START; | |
2234 | gate_vma.vm_end = FIXADDR_USER_END; | |
2235 | gate_vma.vm_page_prot = PAGE_READONLY; | |
2236 | gate_vma.vm_flags = 0; | |
2237 | return 0; | |
2238 | } | |
2239 | __initcall(gate_vma_init); | |
2240 | #endif | |
2241 | ||
2242 | struct vm_area_struct *get_gate_vma(struct task_struct *tsk) | |
2243 | { | |
2244 | #ifdef AT_SYSINFO_EHDR | |
2245 | return &gate_vma; | |
2246 | #else | |
2247 | return NULL; | |
2248 | #endif | |
2249 | } | |
2250 | ||
2251 | int in_gate_area_no_task(unsigned long addr) | |
2252 | { | |
2253 | #ifdef AT_SYSINFO_EHDR | |
2254 | if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END)) | |
2255 | return 1; | |
2256 | #endif | |
2257 | return 0; | |
2258 | } | |
2259 | ||
2260 | #endif /* __HAVE_ARCH_GATE_AREA */ |