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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); | |
4c21e2f2 | 117 | pte_lock_deinit(page); |
e0da382c HD |
118 | pte_free_tlb(tlb, page); |
119 | dec_page_state(nr_page_table_pages); | |
120 | tlb->mm->nr_ptes--; | |
1da177e4 LT |
121 | } |
122 | ||
e0da382c HD |
123 | static inline void free_pmd_range(struct mmu_gather *tlb, pud_t *pud, |
124 | unsigned long addr, unsigned long end, | |
125 | unsigned long floor, unsigned long ceiling) | |
1da177e4 LT |
126 | { |
127 | pmd_t *pmd; | |
128 | unsigned long next; | |
e0da382c | 129 | unsigned long start; |
1da177e4 | 130 | |
e0da382c | 131 | start = addr; |
1da177e4 | 132 | pmd = pmd_offset(pud, addr); |
1da177e4 LT |
133 | do { |
134 | next = pmd_addr_end(addr, end); | |
135 | if (pmd_none_or_clear_bad(pmd)) | |
136 | continue; | |
e0da382c | 137 | free_pte_range(tlb, pmd); |
1da177e4 LT |
138 | } while (pmd++, addr = next, addr != end); |
139 | ||
e0da382c HD |
140 | start &= PUD_MASK; |
141 | if (start < floor) | |
142 | return; | |
143 | if (ceiling) { | |
144 | ceiling &= PUD_MASK; | |
145 | if (!ceiling) | |
146 | return; | |
1da177e4 | 147 | } |
e0da382c HD |
148 | if (end - 1 > ceiling - 1) |
149 | return; | |
150 | ||
151 | pmd = pmd_offset(pud, start); | |
152 | pud_clear(pud); | |
153 | pmd_free_tlb(tlb, pmd); | |
1da177e4 LT |
154 | } |
155 | ||
e0da382c HD |
156 | static inline void free_pud_range(struct mmu_gather *tlb, pgd_t *pgd, |
157 | unsigned long addr, unsigned long end, | |
158 | unsigned long floor, unsigned long ceiling) | |
1da177e4 LT |
159 | { |
160 | pud_t *pud; | |
161 | unsigned long next; | |
e0da382c | 162 | unsigned long start; |
1da177e4 | 163 | |
e0da382c | 164 | start = addr; |
1da177e4 | 165 | pud = pud_offset(pgd, addr); |
1da177e4 LT |
166 | do { |
167 | next = pud_addr_end(addr, end); | |
168 | if (pud_none_or_clear_bad(pud)) | |
169 | continue; | |
e0da382c | 170 | free_pmd_range(tlb, pud, addr, next, floor, ceiling); |
1da177e4 LT |
171 | } while (pud++, addr = next, addr != end); |
172 | ||
e0da382c HD |
173 | start &= PGDIR_MASK; |
174 | if (start < floor) | |
175 | return; | |
176 | if (ceiling) { | |
177 | ceiling &= PGDIR_MASK; | |
178 | if (!ceiling) | |
179 | return; | |
1da177e4 | 180 | } |
e0da382c HD |
181 | if (end - 1 > ceiling - 1) |
182 | return; | |
183 | ||
184 | pud = pud_offset(pgd, start); | |
185 | pgd_clear(pgd); | |
186 | pud_free_tlb(tlb, pud); | |
1da177e4 LT |
187 | } |
188 | ||
189 | /* | |
e0da382c HD |
190 | * This function frees user-level page tables of a process. |
191 | * | |
1da177e4 LT |
192 | * Must be called with pagetable lock held. |
193 | */ | |
3bf5ee95 | 194 | void free_pgd_range(struct mmu_gather **tlb, |
e0da382c HD |
195 | unsigned long addr, unsigned long end, |
196 | unsigned long floor, unsigned long ceiling) | |
1da177e4 LT |
197 | { |
198 | pgd_t *pgd; | |
199 | unsigned long next; | |
e0da382c HD |
200 | unsigned long start; |
201 | ||
202 | /* | |
203 | * The next few lines have given us lots of grief... | |
204 | * | |
205 | * Why are we testing PMD* at this top level? Because often | |
206 | * there will be no work to do at all, and we'd prefer not to | |
207 | * go all the way down to the bottom just to discover that. | |
208 | * | |
209 | * Why all these "- 1"s? Because 0 represents both the bottom | |
210 | * of the address space and the top of it (using -1 for the | |
211 | * top wouldn't help much: the masks would do the wrong thing). | |
212 | * The rule is that addr 0 and floor 0 refer to the bottom of | |
213 | * the address space, but end 0 and ceiling 0 refer to the top | |
214 | * Comparisons need to use "end - 1" and "ceiling - 1" (though | |
215 | * that end 0 case should be mythical). | |
216 | * | |
217 | * Wherever addr is brought up or ceiling brought down, we must | |
218 | * be careful to reject "the opposite 0" before it confuses the | |
219 | * subsequent tests. But what about where end is brought down | |
220 | * by PMD_SIZE below? no, end can't go down to 0 there. | |
221 | * | |
222 | * Whereas we round start (addr) and ceiling down, by different | |
223 | * masks at different levels, in order to test whether a table | |
224 | * now has no other vmas using it, so can be freed, we don't | |
225 | * bother to round floor or end up - the tests don't need that. | |
226 | */ | |
1da177e4 | 227 | |
e0da382c HD |
228 | addr &= PMD_MASK; |
229 | if (addr < floor) { | |
230 | addr += PMD_SIZE; | |
231 | if (!addr) | |
232 | return; | |
233 | } | |
234 | if (ceiling) { | |
235 | ceiling &= PMD_MASK; | |
236 | if (!ceiling) | |
237 | return; | |
238 | } | |
239 | if (end - 1 > ceiling - 1) | |
240 | end -= PMD_SIZE; | |
241 | if (addr > end - 1) | |
242 | return; | |
243 | ||
244 | start = addr; | |
3bf5ee95 | 245 | pgd = pgd_offset((*tlb)->mm, addr); |
1da177e4 LT |
246 | do { |
247 | next = pgd_addr_end(addr, end); | |
248 | if (pgd_none_or_clear_bad(pgd)) | |
249 | continue; | |
3bf5ee95 | 250 | free_pud_range(*tlb, pgd, addr, next, floor, ceiling); |
1da177e4 | 251 | } while (pgd++, addr = next, addr != end); |
e0da382c | 252 | |
4d6ddfa9 | 253 | if (!(*tlb)->fullmm) |
3bf5ee95 | 254 | flush_tlb_pgtables((*tlb)->mm, start, end); |
e0da382c HD |
255 | } |
256 | ||
257 | void free_pgtables(struct mmu_gather **tlb, struct vm_area_struct *vma, | |
3bf5ee95 | 258 | unsigned long floor, unsigned long ceiling) |
e0da382c HD |
259 | { |
260 | while (vma) { | |
261 | struct vm_area_struct *next = vma->vm_next; | |
262 | unsigned long addr = vma->vm_start; | |
263 | ||
8f4f8c16 HD |
264 | /* |
265 | * Hide vma from rmap and vmtruncate before freeing pgtables | |
266 | */ | |
267 | anon_vma_unlink(vma); | |
268 | unlink_file_vma(vma); | |
269 | ||
3bf5ee95 HD |
270 | if (is_hugepage_only_range(vma->vm_mm, addr, HPAGE_SIZE)) { |
271 | hugetlb_free_pgd_range(tlb, addr, vma->vm_end, | |
e0da382c | 272 | floor, next? next->vm_start: ceiling); |
3bf5ee95 HD |
273 | } else { |
274 | /* | |
275 | * Optimization: gather nearby vmas into one call down | |
276 | */ | |
277 | while (next && next->vm_start <= vma->vm_end + PMD_SIZE | |
278 | && !is_hugepage_only_range(vma->vm_mm, next->vm_start, | |
279 | HPAGE_SIZE)) { | |
280 | vma = next; | |
281 | next = vma->vm_next; | |
8f4f8c16 HD |
282 | anon_vma_unlink(vma); |
283 | unlink_file_vma(vma); | |
3bf5ee95 HD |
284 | } |
285 | free_pgd_range(tlb, addr, vma->vm_end, | |
286 | floor, next? next->vm_start: ceiling); | |
287 | } | |
e0da382c HD |
288 | vma = next; |
289 | } | |
1da177e4 LT |
290 | } |
291 | ||
1bb3630e | 292 | int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address) |
1da177e4 | 293 | { |
c74df32c | 294 | struct page *new = pte_alloc_one(mm, address); |
1bb3630e HD |
295 | if (!new) |
296 | return -ENOMEM; | |
297 | ||
4c21e2f2 | 298 | pte_lock_init(new); |
c74df32c | 299 | spin_lock(&mm->page_table_lock); |
4c21e2f2 HD |
300 | if (pmd_present(*pmd)) { /* Another has populated it */ |
301 | pte_lock_deinit(new); | |
1bb3630e | 302 | pte_free(new); |
4c21e2f2 | 303 | } else { |
1da177e4 LT |
304 | mm->nr_ptes++; |
305 | inc_page_state(nr_page_table_pages); | |
306 | pmd_populate(mm, pmd, new); | |
307 | } | |
c74df32c | 308 | spin_unlock(&mm->page_table_lock); |
1bb3630e | 309 | return 0; |
1da177e4 LT |
310 | } |
311 | ||
1bb3630e | 312 | int __pte_alloc_kernel(pmd_t *pmd, unsigned long address) |
1da177e4 | 313 | { |
1bb3630e HD |
314 | pte_t *new = pte_alloc_one_kernel(&init_mm, address); |
315 | if (!new) | |
316 | return -ENOMEM; | |
317 | ||
318 | spin_lock(&init_mm.page_table_lock); | |
319 | if (pmd_present(*pmd)) /* Another has populated it */ | |
320 | pte_free_kernel(new); | |
321 | else | |
322 | pmd_populate_kernel(&init_mm, pmd, new); | |
323 | spin_unlock(&init_mm.page_table_lock); | |
324 | return 0; | |
1da177e4 LT |
325 | } |
326 | ||
ae859762 HD |
327 | static inline void add_mm_rss(struct mm_struct *mm, int file_rss, int anon_rss) |
328 | { | |
329 | if (file_rss) | |
330 | add_mm_counter(mm, file_rss, file_rss); | |
331 | if (anon_rss) | |
332 | add_mm_counter(mm, anon_rss, anon_rss); | |
333 | } | |
334 | ||
b5810039 NP |
335 | /* |
336 | * This function is called to print an error when a pte in a | |
337 | * !VM_RESERVED region is found pointing to an invalid pfn (which | |
338 | * is an error. | |
339 | * | |
340 | * The calling function must still handle the error. | |
341 | */ | |
342 | void print_bad_pte(struct vm_area_struct *vma, pte_t pte, unsigned long vaddr) | |
343 | { | |
344 | printk(KERN_ERR "Bad pte = %08llx, process = %s, " | |
345 | "vm_flags = %lx, vaddr = %lx\n", | |
346 | (long long)pte_val(pte), | |
347 | (vma->vm_mm == current->mm ? current->comm : "???"), | |
348 | vma->vm_flags, vaddr); | |
349 | dump_stack(); | |
350 | } | |
351 | ||
1da177e4 LT |
352 | /* |
353 | * copy one vm_area from one task to the other. Assumes the page tables | |
354 | * already present in the new task to be cleared in the whole range | |
355 | * covered by this vma. | |
1da177e4 LT |
356 | */ |
357 | ||
8c103762 | 358 | static inline void |
1da177e4 | 359 | copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm, |
b5810039 | 360 | pte_t *dst_pte, pte_t *src_pte, struct vm_area_struct *vma, |
8c103762 | 361 | unsigned long addr, int *rss) |
1da177e4 | 362 | { |
b5810039 | 363 | unsigned long vm_flags = vma->vm_flags; |
1da177e4 LT |
364 | pte_t pte = *src_pte; |
365 | struct page *page; | |
366 | unsigned long pfn; | |
367 | ||
368 | /* pte contains position in swap or file, so copy. */ | |
369 | if (unlikely(!pte_present(pte))) { | |
370 | if (!pte_file(pte)) { | |
371 | swap_duplicate(pte_to_swp_entry(pte)); | |
372 | /* make sure dst_mm is on swapoff's mmlist. */ | |
373 | if (unlikely(list_empty(&dst_mm->mmlist))) { | |
374 | spin_lock(&mmlist_lock); | |
375 | list_add(&dst_mm->mmlist, &src_mm->mmlist); | |
376 | spin_unlock(&mmlist_lock); | |
377 | } | |
378 | } | |
ae859762 | 379 | goto out_set_pte; |
1da177e4 LT |
380 | } |
381 | ||
b5810039 NP |
382 | /* If the region is VM_RESERVED, the mapping is not |
383 | * mapped via rmap - duplicate the pte as is. | |
384 | */ | |
385 | if (vm_flags & VM_RESERVED) | |
386 | goto out_set_pte; | |
387 | ||
1da177e4 | 388 | pfn = pte_pfn(pte); |
b5810039 NP |
389 | /* If the pte points outside of valid memory but |
390 | * the region is not VM_RESERVED, we have a problem. | |
1da177e4 | 391 | */ |
b5810039 NP |
392 | if (unlikely(!pfn_valid(pfn))) { |
393 | print_bad_pte(vma, pte, addr); | |
394 | goto out_set_pte; /* try to do something sane */ | |
395 | } | |
1da177e4 | 396 | |
b5810039 | 397 | page = pfn_to_page(pfn); |
1da177e4 LT |
398 | |
399 | /* | |
400 | * If it's a COW mapping, write protect it both | |
401 | * in the parent and the child | |
402 | */ | |
403 | if ((vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE) { | |
404 | ptep_set_wrprotect(src_mm, addr, src_pte); | |
405 | pte = *src_pte; | |
406 | } | |
407 | ||
408 | /* | |
409 | * If it's a shared mapping, mark it clean in | |
410 | * the child | |
411 | */ | |
412 | if (vm_flags & VM_SHARED) | |
413 | pte = pte_mkclean(pte); | |
414 | pte = pte_mkold(pte); | |
415 | get_page(page); | |
1da177e4 | 416 | page_dup_rmap(page); |
8c103762 | 417 | rss[!!PageAnon(page)]++; |
ae859762 HD |
418 | |
419 | out_set_pte: | |
420 | set_pte_at(dst_mm, addr, dst_pte, pte); | |
1da177e4 LT |
421 | } |
422 | ||
423 | static int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm, | |
424 | pmd_t *dst_pmd, pmd_t *src_pmd, struct vm_area_struct *vma, | |
425 | unsigned long addr, unsigned long end) | |
426 | { | |
427 | pte_t *src_pte, *dst_pte; | |
c74df32c | 428 | spinlock_t *src_ptl, *dst_ptl; |
e040f218 | 429 | int progress = 0; |
8c103762 | 430 | int rss[2]; |
1da177e4 LT |
431 | |
432 | again: | |
ae859762 | 433 | rss[1] = rss[0] = 0; |
c74df32c | 434 | dst_pte = pte_alloc_map_lock(dst_mm, dst_pmd, addr, &dst_ptl); |
1da177e4 LT |
435 | if (!dst_pte) |
436 | return -ENOMEM; | |
437 | src_pte = pte_offset_map_nested(src_pmd, addr); | |
4c21e2f2 | 438 | src_ptl = pte_lockptr(src_mm, src_pmd); |
c74df32c | 439 | spin_lock(src_ptl); |
1da177e4 | 440 | |
1da177e4 LT |
441 | do { |
442 | /* | |
443 | * We are holding two locks at this point - either of them | |
444 | * could generate latencies in another task on another CPU. | |
445 | */ | |
e040f218 HD |
446 | if (progress >= 32) { |
447 | progress = 0; | |
448 | if (need_resched() || | |
c74df32c HD |
449 | need_lockbreak(src_ptl) || |
450 | need_lockbreak(dst_ptl)) | |
e040f218 HD |
451 | break; |
452 | } | |
1da177e4 LT |
453 | if (pte_none(*src_pte)) { |
454 | progress++; | |
455 | continue; | |
456 | } | |
8c103762 | 457 | copy_one_pte(dst_mm, src_mm, dst_pte, src_pte, vma, addr, rss); |
1da177e4 LT |
458 | progress += 8; |
459 | } while (dst_pte++, src_pte++, addr += PAGE_SIZE, addr != end); | |
1da177e4 | 460 | |
c74df32c | 461 | spin_unlock(src_ptl); |
1da177e4 | 462 | pte_unmap_nested(src_pte - 1); |
ae859762 | 463 | add_mm_rss(dst_mm, rss[0], rss[1]); |
c74df32c HD |
464 | pte_unmap_unlock(dst_pte - 1, dst_ptl); |
465 | cond_resched(); | |
1da177e4 LT |
466 | if (addr != end) |
467 | goto again; | |
468 | return 0; | |
469 | } | |
470 | ||
471 | static inline int copy_pmd_range(struct mm_struct *dst_mm, struct mm_struct *src_mm, | |
472 | pud_t *dst_pud, pud_t *src_pud, struct vm_area_struct *vma, | |
473 | unsigned long addr, unsigned long end) | |
474 | { | |
475 | pmd_t *src_pmd, *dst_pmd; | |
476 | unsigned long next; | |
477 | ||
478 | dst_pmd = pmd_alloc(dst_mm, dst_pud, addr); | |
479 | if (!dst_pmd) | |
480 | return -ENOMEM; | |
481 | src_pmd = pmd_offset(src_pud, addr); | |
482 | do { | |
483 | next = pmd_addr_end(addr, end); | |
484 | if (pmd_none_or_clear_bad(src_pmd)) | |
485 | continue; | |
486 | if (copy_pte_range(dst_mm, src_mm, dst_pmd, src_pmd, | |
487 | vma, addr, next)) | |
488 | return -ENOMEM; | |
489 | } while (dst_pmd++, src_pmd++, addr = next, addr != end); | |
490 | return 0; | |
491 | } | |
492 | ||
493 | static inline int copy_pud_range(struct mm_struct *dst_mm, struct mm_struct *src_mm, | |
494 | pgd_t *dst_pgd, pgd_t *src_pgd, struct vm_area_struct *vma, | |
495 | unsigned long addr, unsigned long end) | |
496 | { | |
497 | pud_t *src_pud, *dst_pud; | |
498 | unsigned long next; | |
499 | ||
500 | dst_pud = pud_alloc(dst_mm, dst_pgd, addr); | |
501 | if (!dst_pud) | |
502 | return -ENOMEM; | |
503 | src_pud = pud_offset(src_pgd, addr); | |
504 | do { | |
505 | next = pud_addr_end(addr, end); | |
506 | if (pud_none_or_clear_bad(src_pud)) | |
507 | continue; | |
508 | if (copy_pmd_range(dst_mm, src_mm, dst_pud, src_pud, | |
509 | vma, addr, next)) | |
510 | return -ENOMEM; | |
511 | } while (dst_pud++, src_pud++, addr = next, addr != end); | |
512 | return 0; | |
513 | } | |
514 | ||
515 | int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm, | |
516 | struct vm_area_struct *vma) | |
517 | { | |
518 | pgd_t *src_pgd, *dst_pgd; | |
519 | unsigned long next; | |
520 | unsigned long addr = vma->vm_start; | |
521 | unsigned long end = vma->vm_end; | |
522 | ||
d992895b NP |
523 | /* |
524 | * Don't copy ptes where a page fault will fill them correctly. | |
525 | * Fork becomes much lighter when there are big shared or private | |
526 | * readonly mappings. The tradeoff is that copy_page_range is more | |
527 | * efficient than faulting. | |
528 | */ | |
529 | if (!(vma->vm_flags & (VM_HUGETLB|VM_NONLINEAR|VM_RESERVED))) { | |
530 | if (!vma->anon_vma) | |
531 | return 0; | |
532 | } | |
533 | ||
1da177e4 LT |
534 | if (is_vm_hugetlb_page(vma)) |
535 | return copy_hugetlb_page_range(dst_mm, src_mm, vma); | |
536 | ||
537 | dst_pgd = pgd_offset(dst_mm, addr); | |
538 | src_pgd = pgd_offset(src_mm, addr); | |
539 | do { | |
540 | next = pgd_addr_end(addr, end); | |
541 | if (pgd_none_or_clear_bad(src_pgd)) | |
542 | continue; | |
543 | if (copy_pud_range(dst_mm, src_mm, dst_pgd, src_pgd, | |
544 | vma, addr, next)) | |
545 | return -ENOMEM; | |
546 | } while (dst_pgd++, src_pgd++, addr = next, addr != end); | |
547 | return 0; | |
548 | } | |
549 | ||
b5810039 NP |
550 | static void zap_pte_range(struct mmu_gather *tlb, |
551 | struct vm_area_struct *vma, pmd_t *pmd, | |
1da177e4 LT |
552 | unsigned long addr, unsigned long end, |
553 | struct zap_details *details) | |
554 | { | |
b5810039 | 555 | struct mm_struct *mm = tlb->mm; |
1da177e4 | 556 | pte_t *pte; |
508034a3 | 557 | spinlock_t *ptl; |
ae859762 HD |
558 | int file_rss = 0; |
559 | int anon_rss = 0; | |
1da177e4 | 560 | |
508034a3 | 561 | pte = pte_offset_map_lock(mm, pmd, addr, &ptl); |
1da177e4 LT |
562 | do { |
563 | pte_t ptent = *pte; | |
564 | if (pte_none(ptent)) | |
565 | continue; | |
566 | if (pte_present(ptent)) { | |
567 | struct page *page = NULL; | |
b5810039 NP |
568 | if (!(vma->vm_flags & VM_RESERVED)) { |
569 | unsigned long pfn = pte_pfn(ptent); | |
570 | if (unlikely(!pfn_valid(pfn))) | |
571 | print_bad_pte(vma, ptent, addr); | |
572 | else | |
573 | page = pfn_to_page(pfn); | |
1da177e4 LT |
574 | } |
575 | if (unlikely(details) && page) { | |
576 | /* | |
577 | * unmap_shared_mapping_pages() wants to | |
578 | * invalidate cache without truncating: | |
579 | * unmap shared but keep private pages. | |
580 | */ | |
581 | if (details->check_mapping && | |
582 | details->check_mapping != page->mapping) | |
583 | continue; | |
584 | /* | |
585 | * Each page->index must be checked when | |
586 | * invalidating or truncating nonlinear. | |
587 | */ | |
588 | if (details->nonlinear_vma && | |
589 | (page->index < details->first_index || | |
590 | page->index > details->last_index)) | |
591 | continue; | |
592 | } | |
b5810039 | 593 | ptent = ptep_get_and_clear_full(mm, addr, pte, |
a600388d | 594 | tlb->fullmm); |
1da177e4 LT |
595 | tlb_remove_tlb_entry(tlb, pte, addr); |
596 | if (unlikely(!page)) | |
597 | continue; | |
598 | if (unlikely(details) && details->nonlinear_vma | |
599 | && linear_page_index(details->nonlinear_vma, | |
600 | addr) != page->index) | |
b5810039 | 601 | set_pte_at(mm, addr, pte, |
1da177e4 | 602 | pgoff_to_pte(page->index)); |
1da177e4 | 603 | if (PageAnon(page)) |
86d912f4 | 604 | anon_rss--; |
6237bcd9 HD |
605 | else { |
606 | if (pte_dirty(ptent)) | |
607 | set_page_dirty(page); | |
608 | if (pte_young(ptent)) | |
609 | mark_page_accessed(page); | |
86d912f4 | 610 | file_rss--; |
6237bcd9 | 611 | } |
1da177e4 LT |
612 | page_remove_rmap(page); |
613 | tlb_remove_page(tlb, page); | |
614 | continue; | |
615 | } | |
616 | /* | |
617 | * If details->check_mapping, we leave swap entries; | |
618 | * if details->nonlinear_vma, we leave file entries. | |
619 | */ | |
620 | if (unlikely(details)) | |
621 | continue; | |
622 | if (!pte_file(ptent)) | |
623 | free_swap_and_cache(pte_to_swp_entry(ptent)); | |
b5810039 | 624 | pte_clear_full(mm, addr, pte, tlb->fullmm); |
1da177e4 | 625 | } while (pte++, addr += PAGE_SIZE, addr != end); |
ae859762 | 626 | |
86d912f4 | 627 | add_mm_rss(mm, file_rss, anon_rss); |
508034a3 | 628 | pte_unmap_unlock(pte - 1, ptl); |
1da177e4 LT |
629 | } |
630 | ||
b5810039 NP |
631 | static inline void zap_pmd_range(struct mmu_gather *tlb, |
632 | struct vm_area_struct *vma, pud_t *pud, | |
1da177e4 LT |
633 | unsigned long addr, unsigned long end, |
634 | struct zap_details *details) | |
635 | { | |
636 | pmd_t *pmd; | |
637 | unsigned long next; | |
638 | ||
639 | pmd = pmd_offset(pud, addr); | |
640 | do { | |
641 | next = pmd_addr_end(addr, end); | |
642 | if (pmd_none_or_clear_bad(pmd)) | |
643 | continue; | |
b5810039 | 644 | zap_pte_range(tlb, vma, pmd, addr, next, details); |
1da177e4 LT |
645 | } while (pmd++, addr = next, addr != end); |
646 | } | |
647 | ||
b5810039 NP |
648 | static inline void zap_pud_range(struct mmu_gather *tlb, |
649 | struct vm_area_struct *vma, pgd_t *pgd, | |
1da177e4 LT |
650 | unsigned long addr, unsigned long end, |
651 | struct zap_details *details) | |
652 | { | |
653 | pud_t *pud; | |
654 | unsigned long next; | |
655 | ||
656 | pud = pud_offset(pgd, addr); | |
657 | do { | |
658 | next = pud_addr_end(addr, end); | |
659 | if (pud_none_or_clear_bad(pud)) | |
660 | continue; | |
b5810039 | 661 | zap_pmd_range(tlb, vma, pud, addr, next, details); |
1da177e4 LT |
662 | } while (pud++, addr = next, addr != end); |
663 | } | |
664 | ||
665 | static void unmap_page_range(struct mmu_gather *tlb, struct vm_area_struct *vma, | |
666 | unsigned long addr, unsigned long end, | |
667 | struct zap_details *details) | |
668 | { | |
669 | pgd_t *pgd; | |
670 | unsigned long next; | |
671 | ||
672 | if (details && !details->check_mapping && !details->nonlinear_vma) | |
673 | details = NULL; | |
674 | ||
675 | BUG_ON(addr >= end); | |
676 | tlb_start_vma(tlb, vma); | |
677 | pgd = pgd_offset(vma->vm_mm, addr); | |
678 | do { | |
679 | next = pgd_addr_end(addr, end); | |
680 | if (pgd_none_or_clear_bad(pgd)) | |
681 | continue; | |
b5810039 | 682 | zap_pud_range(tlb, vma, pgd, addr, next, details); |
1da177e4 LT |
683 | } while (pgd++, addr = next, addr != end); |
684 | tlb_end_vma(tlb, vma); | |
685 | } | |
686 | ||
687 | #ifdef CONFIG_PREEMPT | |
688 | # define ZAP_BLOCK_SIZE (8 * PAGE_SIZE) | |
689 | #else | |
690 | /* No preempt: go for improved straight-line efficiency */ | |
691 | # define ZAP_BLOCK_SIZE (1024 * PAGE_SIZE) | |
692 | #endif | |
693 | ||
694 | /** | |
695 | * unmap_vmas - unmap a range of memory covered by a list of vma's | |
696 | * @tlbp: address of the caller's struct mmu_gather | |
1da177e4 LT |
697 | * @vma: the starting vma |
698 | * @start_addr: virtual address at which to start unmapping | |
699 | * @end_addr: virtual address at which to end unmapping | |
700 | * @nr_accounted: Place number of unmapped pages in vm-accountable vma's here | |
701 | * @details: details of nonlinear truncation or shared cache invalidation | |
702 | * | |
ee39b37b | 703 | * Returns the end address of the unmapping (restart addr if interrupted). |
1da177e4 | 704 | * |
508034a3 | 705 | * Unmap all pages in the vma list. |
1da177e4 | 706 | * |
508034a3 HD |
707 | * We aim to not hold locks for too long (for scheduling latency reasons). |
708 | * So zap pages in ZAP_BLOCK_SIZE bytecounts. This means we need to | |
1da177e4 LT |
709 | * return the ending mmu_gather to the caller. |
710 | * | |
711 | * Only addresses between `start' and `end' will be unmapped. | |
712 | * | |
713 | * The VMA list must be sorted in ascending virtual address order. | |
714 | * | |
715 | * unmap_vmas() assumes that the caller will flush the whole unmapped address | |
716 | * range after unmap_vmas() returns. So the only responsibility here is to | |
717 | * ensure that any thus-far unmapped pages are flushed before unmap_vmas() | |
718 | * drops the lock and schedules. | |
719 | */ | |
508034a3 | 720 | unsigned long unmap_vmas(struct mmu_gather **tlbp, |
1da177e4 LT |
721 | struct vm_area_struct *vma, unsigned long start_addr, |
722 | unsigned long end_addr, unsigned long *nr_accounted, | |
723 | struct zap_details *details) | |
724 | { | |
725 | unsigned long zap_bytes = ZAP_BLOCK_SIZE; | |
726 | unsigned long tlb_start = 0; /* For tlb_finish_mmu */ | |
727 | int tlb_start_valid = 0; | |
ee39b37b | 728 | unsigned long start = start_addr; |
1da177e4 | 729 | spinlock_t *i_mmap_lock = details? details->i_mmap_lock: NULL; |
4d6ddfa9 | 730 | int fullmm = (*tlbp)->fullmm; |
1da177e4 LT |
731 | |
732 | for ( ; vma && vma->vm_start < end_addr; vma = vma->vm_next) { | |
1da177e4 LT |
733 | unsigned long end; |
734 | ||
735 | start = max(vma->vm_start, start_addr); | |
736 | if (start >= vma->vm_end) | |
737 | continue; | |
738 | end = min(vma->vm_end, end_addr); | |
739 | if (end <= vma->vm_start) | |
740 | continue; | |
741 | ||
742 | if (vma->vm_flags & VM_ACCOUNT) | |
743 | *nr_accounted += (end - start) >> PAGE_SHIFT; | |
744 | ||
1da177e4 LT |
745 | while (start != end) { |
746 | unsigned long block; | |
747 | ||
748 | if (!tlb_start_valid) { | |
749 | tlb_start = start; | |
750 | tlb_start_valid = 1; | |
751 | } | |
752 | ||
753 | if (is_vm_hugetlb_page(vma)) { | |
754 | block = end - start; | |
755 | unmap_hugepage_range(vma, start, end); | |
756 | } else { | |
757 | block = min(zap_bytes, end - start); | |
758 | unmap_page_range(*tlbp, vma, start, | |
759 | start + block, details); | |
760 | } | |
761 | ||
762 | start += block; | |
763 | zap_bytes -= block; | |
764 | if ((long)zap_bytes > 0) | |
765 | continue; | |
766 | ||
767 | tlb_finish_mmu(*tlbp, tlb_start, start); | |
768 | ||
769 | if (need_resched() || | |
1da177e4 LT |
770 | (i_mmap_lock && need_lockbreak(i_mmap_lock))) { |
771 | if (i_mmap_lock) { | |
508034a3 | 772 | *tlbp = NULL; |
1da177e4 LT |
773 | goto out; |
774 | } | |
1da177e4 | 775 | cond_resched(); |
1da177e4 LT |
776 | } |
777 | ||
508034a3 | 778 | *tlbp = tlb_gather_mmu(vma->vm_mm, fullmm); |
1da177e4 LT |
779 | tlb_start_valid = 0; |
780 | zap_bytes = ZAP_BLOCK_SIZE; | |
781 | } | |
782 | } | |
783 | out: | |
ee39b37b | 784 | return start; /* which is now the end (or restart) address */ |
1da177e4 LT |
785 | } |
786 | ||
787 | /** | |
788 | * zap_page_range - remove user pages in a given range | |
789 | * @vma: vm_area_struct holding the applicable pages | |
790 | * @address: starting address of pages to zap | |
791 | * @size: number of bytes to zap | |
792 | * @details: details of nonlinear truncation or shared cache invalidation | |
793 | */ | |
ee39b37b | 794 | unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address, |
1da177e4 LT |
795 | unsigned long size, struct zap_details *details) |
796 | { | |
797 | struct mm_struct *mm = vma->vm_mm; | |
798 | struct mmu_gather *tlb; | |
799 | unsigned long end = address + size; | |
800 | unsigned long nr_accounted = 0; | |
801 | ||
1da177e4 | 802 | lru_add_drain(); |
1da177e4 | 803 | tlb = tlb_gather_mmu(mm, 0); |
365e9c87 | 804 | update_hiwater_rss(mm); |
508034a3 HD |
805 | end = unmap_vmas(&tlb, vma, address, end, &nr_accounted, details); |
806 | if (tlb) | |
807 | tlb_finish_mmu(tlb, address, end); | |
ee39b37b | 808 | return end; |
1da177e4 LT |
809 | } |
810 | ||
811 | /* | |
812 | * Do a quick page-table lookup for a single page. | |
1da177e4 | 813 | */ |
deceb6cd HD |
814 | struct page *follow_page(struct mm_struct *mm, unsigned long address, |
815 | unsigned int flags) | |
1da177e4 LT |
816 | { |
817 | pgd_t *pgd; | |
818 | pud_t *pud; | |
819 | pmd_t *pmd; | |
820 | pte_t *ptep, pte; | |
deceb6cd | 821 | spinlock_t *ptl; |
1da177e4 LT |
822 | unsigned long pfn; |
823 | struct page *page; | |
824 | ||
deceb6cd HD |
825 | page = follow_huge_addr(mm, address, flags & FOLL_WRITE); |
826 | if (!IS_ERR(page)) { | |
827 | BUG_ON(flags & FOLL_GET); | |
828 | goto out; | |
829 | } | |
1da177e4 | 830 | |
deceb6cd | 831 | page = NULL; |
1da177e4 LT |
832 | pgd = pgd_offset(mm, address); |
833 | if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd))) | |
deceb6cd | 834 | goto no_page_table; |
1da177e4 LT |
835 | |
836 | pud = pud_offset(pgd, address); | |
837 | if (pud_none(*pud) || unlikely(pud_bad(*pud))) | |
deceb6cd | 838 | goto no_page_table; |
1da177e4 LT |
839 | |
840 | pmd = pmd_offset(pud, address); | |
841 | if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd))) | |
deceb6cd HD |
842 | goto no_page_table; |
843 | ||
844 | if (pmd_huge(*pmd)) { | |
845 | BUG_ON(flags & FOLL_GET); | |
846 | page = follow_huge_pmd(mm, address, pmd, flags & FOLL_WRITE); | |
1da177e4 | 847 | goto out; |
deceb6cd | 848 | } |
1da177e4 | 849 | |
deceb6cd | 850 | ptep = pte_offset_map_lock(mm, pmd, address, &ptl); |
1da177e4 LT |
851 | if (!ptep) |
852 | goto out; | |
853 | ||
854 | pte = *ptep; | |
deceb6cd HD |
855 | if (!pte_present(pte)) |
856 | goto unlock; | |
857 | if ((flags & FOLL_WRITE) && !pte_write(pte)) | |
858 | goto unlock; | |
859 | pfn = pte_pfn(pte); | |
860 | if (!pfn_valid(pfn)) | |
861 | goto unlock; | |
1da177e4 | 862 | |
deceb6cd HD |
863 | page = pfn_to_page(pfn); |
864 | if (flags & FOLL_GET) | |
865 | get_page(page); | |
866 | if (flags & FOLL_TOUCH) { | |
867 | if ((flags & FOLL_WRITE) && | |
868 | !pte_dirty(pte) && !PageDirty(page)) | |
869 | set_page_dirty(page); | |
870 | mark_page_accessed(page); | |
871 | } | |
872 | unlock: | |
873 | pte_unmap_unlock(ptep, ptl); | |
1da177e4 | 874 | out: |
deceb6cd | 875 | return page; |
1da177e4 | 876 | |
deceb6cd HD |
877 | no_page_table: |
878 | /* | |
879 | * When core dumping an enormous anonymous area that nobody | |
880 | * has touched so far, we don't want to allocate page tables. | |
881 | */ | |
882 | if (flags & FOLL_ANON) { | |
883 | page = ZERO_PAGE(address); | |
884 | if (flags & FOLL_GET) | |
885 | get_page(page); | |
886 | BUG_ON(flags & FOLL_WRITE); | |
887 | } | |
888 | return page; | |
1da177e4 LT |
889 | } |
890 | ||
1da177e4 LT |
891 | int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, |
892 | unsigned long start, int len, int write, int force, | |
893 | struct page **pages, struct vm_area_struct **vmas) | |
894 | { | |
895 | int i; | |
deceb6cd | 896 | unsigned int vm_flags; |
1da177e4 LT |
897 | |
898 | /* | |
899 | * Require read or write permissions. | |
900 | * If 'force' is set, we only require the "MAY" flags. | |
901 | */ | |
deceb6cd HD |
902 | vm_flags = write ? (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD); |
903 | vm_flags &= force ? (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE); | |
1da177e4 LT |
904 | i = 0; |
905 | ||
906 | do { | |
deceb6cd HD |
907 | struct vm_area_struct *vma; |
908 | unsigned int foll_flags; | |
1da177e4 LT |
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 | ||
b5810039 | 948 | if (!vma || (vma->vm_flags & (VM_IO | VM_RESERVED)) |
deceb6cd | 949 | || !(vm_flags & vma->vm_flags)) |
1da177e4 LT |
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 | } | |
deceb6cd HD |
957 | |
958 | foll_flags = FOLL_TOUCH; | |
959 | if (pages) | |
960 | foll_flags |= FOLL_GET; | |
961 | if (!write && !(vma->vm_flags & VM_LOCKED) && | |
962 | (!vma->vm_ops || !vma->vm_ops->nopage)) | |
963 | foll_flags |= FOLL_ANON; | |
964 | ||
1da177e4 | 965 | do { |
08ef4729 | 966 | struct page *page; |
1da177e4 | 967 | |
deceb6cd HD |
968 | if (write) |
969 | foll_flags |= FOLL_WRITE; | |
a68d2ebc | 970 | |
deceb6cd HD |
971 | cond_resched(); |
972 | while (!(page = follow_page(mm, start, foll_flags))) { | |
973 | int ret; | |
974 | ret = __handle_mm_fault(mm, vma, start, | |
975 | foll_flags & FOLL_WRITE); | |
a68d2ebc LT |
976 | /* |
977 | * The VM_FAULT_WRITE bit tells us that do_wp_page has | |
978 | * broken COW when necessary, even if maybe_mkwrite | |
979 | * decided not to set pte_write. We can thus safely do | |
980 | * subsequent page lookups as if they were reads. | |
981 | */ | |
982 | if (ret & VM_FAULT_WRITE) | |
deceb6cd | 983 | foll_flags &= ~FOLL_WRITE; |
a68d2ebc LT |
984 | |
985 | switch (ret & ~VM_FAULT_WRITE) { | |
1da177e4 LT |
986 | case VM_FAULT_MINOR: |
987 | tsk->min_flt++; | |
988 | break; | |
989 | case VM_FAULT_MAJOR: | |
990 | tsk->maj_flt++; | |
991 | break; | |
992 | case VM_FAULT_SIGBUS: | |
993 | return i ? i : -EFAULT; | |
994 | case VM_FAULT_OOM: | |
995 | return i ? i : -ENOMEM; | |
996 | default: | |
997 | BUG(); | |
998 | } | |
1da177e4 LT |
999 | } |
1000 | if (pages) { | |
08ef4729 HD |
1001 | pages[i] = page; |
1002 | flush_dcache_page(page); | |
1da177e4 LT |
1003 | } |
1004 | if (vmas) | |
1005 | vmas[i] = vma; | |
1006 | i++; | |
1007 | start += PAGE_SIZE; | |
1008 | len--; | |
08ef4729 | 1009 | } while (len && start < vma->vm_end); |
08ef4729 | 1010 | } while (len); |
1da177e4 LT |
1011 | return i; |
1012 | } | |
1da177e4 LT |
1013 | EXPORT_SYMBOL(get_user_pages); |
1014 | ||
1015 | static int zeromap_pte_range(struct mm_struct *mm, pmd_t *pmd, | |
1016 | unsigned long addr, unsigned long end, pgprot_t prot) | |
1017 | { | |
1018 | pte_t *pte; | |
c74df32c | 1019 | spinlock_t *ptl; |
1da177e4 | 1020 | |
c74df32c | 1021 | pte = pte_alloc_map_lock(mm, pmd, addr, &ptl); |
1da177e4 LT |
1022 | if (!pte) |
1023 | return -ENOMEM; | |
1024 | do { | |
b5810039 NP |
1025 | struct page *page = ZERO_PAGE(addr); |
1026 | pte_t zero_pte = pte_wrprotect(mk_pte(page, prot)); | |
1027 | page_cache_get(page); | |
1028 | page_add_file_rmap(page); | |
1029 | inc_mm_counter(mm, file_rss); | |
1da177e4 LT |
1030 | BUG_ON(!pte_none(*pte)); |
1031 | set_pte_at(mm, addr, pte, zero_pte); | |
1032 | } while (pte++, addr += PAGE_SIZE, addr != end); | |
c74df32c | 1033 | pte_unmap_unlock(pte - 1, ptl); |
1da177e4 LT |
1034 | return 0; |
1035 | } | |
1036 | ||
1037 | static inline int zeromap_pmd_range(struct mm_struct *mm, pud_t *pud, | |
1038 | unsigned long addr, unsigned long end, pgprot_t prot) | |
1039 | { | |
1040 | pmd_t *pmd; | |
1041 | unsigned long next; | |
1042 | ||
1043 | pmd = pmd_alloc(mm, pud, addr); | |
1044 | if (!pmd) | |
1045 | return -ENOMEM; | |
1046 | do { | |
1047 | next = pmd_addr_end(addr, end); | |
1048 | if (zeromap_pte_range(mm, pmd, addr, next, prot)) | |
1049 | return -ENOMEM; | |
1050 | } while (pmd++, addr = next, addr != end); | |
1051 | return 0; | |
1052 | } | |
1053 | ||
1054 | static inline int zeromap_pud_range(struct mm_struct *mm, pgd_t *pgd, | |
1055 | unsigned long addr, unsigned long end, pgprot_t prot) | |
1056 | { | |
1057 | pud_t *pud; | |
1058 | unsigned long next; | |
1059 | ||
1060 | pud = pud_alloc(mm, pgd, addr); | |
1061 | if (!pud) | |
1062 | return -ENOMEM; | |
1063 | do { | |
1064 | next = pud_addr_end(addr, end); | |
1065 | if (zeromap_pmd_range(mm, pud, addr, next, prot)) | |
1066 | return -ENOMEM; | |
1067 | } while (pud++, addr = next, addr != end); | |
1068 | return 0; | |
1069 | } | |
1070 | ||
1071 | int zeromap_page_range(struct vm_area_struct *vma, | |
1072 | unsigned long addr, unsigned long size, pgprot_t prot) | |
1073 | { | |
1074 | pgd_t *pgd; | |
1075 | unsigned long next; | |
1076 | unsigned long end = addr + size; | |
1077 | struct mm_struct *mm = vma->vm_mm; | |
1078 | int err; | |
1079 | ||
1080 | BUG_ON(addr >= end); | |
1081 | pgd = pgd_offset(mm, addr); | |
1082 | flush_cache_range(vma, addr, end); | |
1da177e4 LT |
1083 | do { |
1084 | next = pgd_addr_end(addr, end); | |
1085 | err = zeromap_pud_range(mm, pgd, addr, next, prot); | |
1086 | if (err) | |
1087 | break; | |
1088 | } while (pgd++, addr = next, addr != end); | |
1da177e4 LT |
1089 | return err; |
1090 | } | |
1091 | ||
1092 | /* | |
1093 | * maps a range of physical memory into the requested pages. the old | |
1094 | * mappings are removed. any references to nonexistent pages results | |
1095 | * in null mappings (currently treated as "copy-on-access") | |
1096 | */ | |
1097 | static int remap_pte_range(struct mm_struct *mm, pmd_t *pmd, | |
1098 | unsigned long addr, unsigned long end, | |
1099 | unsigned long pfn, pgprot_t prot) | |
1100 | { | |
1101 | pte_t *pte; | |
c74df32c | 1102 | spinlock_t *ptl; |
1da177e4 | 1103 | |
c74df32c | 1104 | pte = pte_alloc_map_lock(mm, pmd, addr, &ptl); |
1da177e4 LT |
1105 | if (!pte) |
1106 | return -ENOMEM; | |
1107 | do { | |
1108 | BUG_ON(!pte_none(*pte)); | |
b5810039 | 1109 | set_pte_at(mm, addr, pte, pfn_pte(pfn, prot)); |
1da177e4 LT |
1110 | pfn++; |
1111 | } while (pte++, addr += PAGE_SIZE, addr != end); | |
c74df32c | 1112 | pte_unmap_unlock(pte - 1, ptl); |
1da177e4 LT |
1113 | return 0; |
1114 | } | |
1115 | ||
1116 | static inline int remap_pmd_range(struct mm_struct *mm, pud_t *pud, | |
1117 | unsigned long addr, unsigned long end, | |
1118 | unsigned long pfn, pgprot_t prot) | |
1119 | { | |
1120 | pmd_t *pmd; | |
1121 | unsigned long next; | |
1122 | ||
1123 | pfn -= addr >> PAGE_SHIFT; | |
1124 | pmd = pmd_alloc(mm, pud, addr); | |
1125 | if (!pmd) | |
1126 | return -ENOMEM; | |
1127 | do { | |
1128 | next = pmd_addr_end(addr, end); | |
1129 | if (remap_pte_range(mm, pmd, addr, next, | |
1130 | pfn + (addr >> PAGE_SHIFT), prot)) | |
1131 | return -ENOMEM; | |
1132 | } while (pmd++, addr = next, addr != end); | |
1133 | return 0; | |
1134 | } | |
1135 | ||
1136 | static inline int remap_pud_range(struct mm_struct *mm, pgd_t *pgd, | |
1137 | unsigned long addr, unsigned long end, | |
1138 | unsigned long pfn, pgprot_t prot) | |
1139 | { | |
1140 | pud_t *pud; | |
1141 | unsigned long next; | |
1142 | ||
1143 | pfn -= addr >> PAGE_SHIFT; | |
1144 | pud = pud_alloc(mm, pgd, addr); | |
1145 | if (!pud) | |
1146 | return -ENOMEM; | |
1147 | do { | |
1148 | next = pud_addr_end(addr, end); | |
1149 | if (remap_pmd_range(mm, pud, addr, next, | |
1150 | pfn + (addr >> PAGE_SHIFT), prot)) | |
1151 | return -ENOMEM; | |
1152 | } while (pud++, addr = next, addr != end); | |
1153 | return 0; | |
1154 | } | |
1155 | ||
1156 | /* Note: this is only safe if the mm semaphore is held when called. */ | |
1157 | int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, | |
1158 | unsigned long pfn, unsigned long size, pgprot_t prot) | |
1159 | { | |
1160 | pgd_t *pgd; | |
1161 | unsigned long next; | |
2d15cab8 | 1162 | unsigned long end = addr + PAGE_ALIGN(size); |
1da177e4 LT |
1163 | struct mm_struct *mm = vma->vm_mm; |
1164 | int err; | |
1165 | ||
1166 | /* | |
1167 | * Physically remapped pages are special. Tell the | |
1168 | * rest of the world about it: | |
1169 | * VM_IO tells people not to look at these pages | |
1170 | * (accesses can have side effects). | |
b5810039 NP |
1171 | * VM_RESERVED tells the core MM not to "manage" these pages |
1172 | * (e.g. refcount, mapcount, try to swap them out). | |
1da177e4 LT |
1173 | */ |
1174 | vma->vm_flags |= VM_IO | VM_RESERVED; | |
1175 | ||
1176 | BUG_ON(addr >= end); | |
1177 | pfn -= addr >> PAGE_SHIFT; | |
1178 | pgd = pgd_offset(mm, addr); | |
1179 | flush_cache_range(vma, addr, end); | |
1da177e4 LT |
1180 | do { |
1181 | next = pgd_addr_end(addr, end); | |
1182 | err = remap_pud_range(mm, pgd, addr, next, | |
1183 | pfn + (addr >> PAGE_SHIFT), prot); | |
1184 | if (err) | |
1185 | break; | |
1186 | } while (pgd++, addr = next, addr != end); | |
1da177e4 LT |
1187 | return err; |
1188 | } | |
1189 | EXPORT_SYMBOL(remap_pfn_range); | |
1190 | ||
8f4e2101 HD |
1191 | /* |
1192 | * handle_pte_fault chooses page fault handler according to an entry | |
1193 | * which was read non-atomically. Before making any commitment, on | |
1194 | * those architectures or configurations (e.g. i386 with PAE) which | |
1195 | * might give a mix of unmatched parts, do_swap_page and do_file_page | |
1196 | * must check under lock before unmapping the pte and proceeding | |
1197 | * (but do_wp_page is only called after already making such a check; | |
1198 | * and do_anonymous_page and do_no_page can safely check later on). | |
1199 | */ | |
4c21e2f2 | 1200 | static inline int pte_unmap_same(struct mm_struct *mm, pmd_t *pmd, |
8f4e2101 HD |
1201 | pte_t *page_table, pte_t orig_pte) |
1202 | { | |
1203 | int same = 1; | |
1204 | #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT) | |
1205 | if (sizeof(pte_t) > sizeof(unsigned long)) { | |
4c21e2f2 HD |
1206 | spinlock_t *ptl = pte_lockptr(mm, pmd); |
1207 | spin_lock(ptl); | |
8f4e2101 | 1208 | same = pte_same(*page_table, orig_pte); |
4c21e2f2 | 1209 | spin_unlock(ptl); |
8f4e2101 HD |
1210 | } |
1211 | #endif | |
1212 | pte_unmap(page_table); | |
1213 | return same; | |
1214 | } | |
1215 | ||
1da177e4 LT |
1216 | /* |
1217 | * Do pte_mkwrite, but only if the vma says VM_WRITE. We do this when | |
1218 | * servicing faults for write access. In the normal case, do always want | |
1219 | * pte_mkwrite. But get_user_pages can cause write faults for mappings | |
1220 | * that do not have writing enabled, when used by access_process_vm. | |
1221 | */ | |
1222 | static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) | |
1223 | { | |
1224 | if (likely(vma->vm_flags & VM_WRITE)) | |
1225 | pte = pte_mkwrite(pte); | |
1226 | return pte; | |
1227 | } | |
1228 | ||
1da177e4 LT |
1229 | /* |
1230 | * This routine handles present pages, when users try to write | |
1231 | * to a shared page. It is done by copying the page to a new address | |
1232 | * and decrementing the shared-page counter for the old page. | |
1233 | * | |
1da177e4 LT |
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 | * | |
8f4e2101 HD |
1243 | * We enter with non-exclusive mmap_sem (to exclude vma changes, |
1244 | * but allow concurrent faults), with pte both mapped and locked. | |
1245 | * We return with mmap_sem still held, but pte unmapped and unlocked. | |
1da177e4 | 1246 | */ |
65500d23 HD |
1247 | static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, |
1248 | unsigned long address, pte_t *page_table, pmd_t *pmd, | |
8f4e2101 | 1249 | spinlock_t *ptl, pte_t orig_pte) |
1da177e4 LT |
1250 | { |
1251 | struct page *old_page, *new_page; | |
65500d23 | 1252 | unsigned long pfn = pte_pfn(orig_pte); |
1da177e4 | 1253 | pte_t entry; |
65500d23 | 1254 | int ret = VM_FAULT_MINOR; |
1da177e4 | 1255 | |
b5810039 NP |
1256 | BUG_ON(vma->vm_flags & VM_RESERVED); |
1257 | ||
1da177e4 LT |
1258 | if (unlikely(!pfn_valid(pfn))) { |
1259 | /* | |
65500d23 | 1260 | * Page table corrupted: show pte and kill process. |
1da177e4 | 1261 | */ |
b5810039 | 1262 | print_bad_pte(vma, orig_pte, address); |
65500d23 HD |
1263 | ret = VM_FAULT_OOM; |
1264 | goto unlock; | |
1da177e4 LT |
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); | |
65500d23 HD |
1273 | entry = pte_mkyoung(orig_pte); |
1274 | entry = maybe_mkwrite(pte_mkdirty(entry), vma); | |
1da177e4 LT |
1275 | ptep_set_access_flags(vma, address, page_table, entry, 1); |
1276 | update_mmu_cache(vma, address, entry); | |
1277 | lazy_mmu_prot_update(entry); | |
65500d23 HD |
1278 | ret |= VM_FAULT_WRITE; |
1279 | goto unlock; | |
1da177e4 LT |
1280 | } |
1281 | } | |
1da177e4 LT |
1282 | |
1283 | /* | |
1284 | * Ok, we need to copy. Oh, well.. | |
1285 | */ | |
b5810039 | 1286 | page_cache_get(old_page); |
8f4e2101 | 1287 | pte_unmap_unlock(page_table, ptl); |
1da177e4 LT |
1288 | |
1289 | if (unlikely(anon_vma_prepare(vma))) | |
65500d23 | 1290 | goto oom; |
1da177e4 LT |
1291 | if (old_page == ZERO_PAGE(address)) { |
1292 | new_page = alloc_zeroed_user_highpage(vma, address); | |
1293 | if (!new_page) | |
65500d23 | 1294 | goto oom; |
1da177e4 LT |
1295 | } else { |
1296 | new_page = alloc_page_vma(GFP_HIGHUSER, vma, address); | |
1297 | if (!new_page) | |
65500d23 | 1298 | goto oom; |
1da177e4 LT |
1299 | copy_user_highpage(new_page, old_page, address); |
1300 | } | |
65500d23 | 1301 | |
1da177e4 LT |
1302 | /* |
1303 | * Re-check the pte - we dropped the lock | |
1304 | */ | |
8f4e2101 | 1305 | page_table = pte_offset_map_lock(mm, pmd, address, &ptl); |
65500d23 | 1306 | if (likely(pte_same(*page_table, orig_pte))) { |
b5810039 NP |
1307 | page_remove_rmap(old_page); |
1308 | if (!PageAnon(old_page)) { | |
4294621f | 1309 | inc_mm_counter(mm, anon_rss); |
b5810039 | 1310 | dec_mm_counter(mm, file_rss); |
4294621f | 1311 | } |
1da177e4 | 1312 | flush_cache_page(vma, address, pfn); |
65500d23 HD |
1313 | entry = mk_pte(new_page, vma->vm_page_prot); |
1314 | entry = maybe_mkwrite(pte_mkdirty(entry), vma); | |
1315 | ptep_establish(vma, address, page_table, entry); | |
1316 | update_mmu_cache(vma, address, entry); | |
1317 | lazy_mmu_prot_update(entry); | |
1da177e4 LT |
1318 | lru_cache_add_active(new_page); |
1319 | page_add_anon_rmap(new_page, vma, address); | |
1320 | ||
1321 | /* Free the old page.. */ | |
1322 | new_page = old_page; | |
f33ea7f4 | 1323 | ret |= VM_FAULT_WRITE; |
1da177e4 | 1324 | } |
1da177e4 LT |
1325 | page_cache_release(new_page); |
1326 | page_cache_release(old_page); | |
65500d23 | 1327 | unlock: |
8f4e2101 | 1328 | pte_unmap_unlock(page_table, ptl); |
f33ea7f4 | 1329 | return ret; |
65500d23 | 1330 | oom: |
1da177e4 LT |
1331 | page_cache_release(old_page); |
1332 | return VM_FAULT_OOM; | |
1333 | } | |
1334 | ||
1335 | /* | |
1336 | * Helper functions for unmap_mapping_range(). | |
1337 | * | |
1338 | * __ Notes on dropping i_mmap_lock to reduce latency while unmapping __ | |
1339 | * | |
1340 | * We have to restart searching the prio_tree whenever we drop the lock, | |
1341 | * since the iterator is only valid while the lock is held, and anyway | |
1342 | * a later vma might be split and reinserted earlier while lock dropped. | |
1343 | * | |
1344 | * The list of nonlinear vmas could be handled more efficiently, using | |
1345 | * a placeholder, but handle it in the same way until a need is shown. | |
1346 | * It is important to search the prio_tree before nonlinear list: a vma | |
1347 | * may become nonlinear and be shifted from prio_tree to nonlinear list | |
1348 | * while the lock is dropped; but never shifted from list to prio_tree. | |
1349 | * | |
1350 | * In order to make forward progress despite restarting the search, | |
1351 | * vm_truncate_count is used to mark a vma as now dealt with, so we can | |
1352 | * quickly skip it next time around. Since the prio_tree search only | |
1353 | * shows us those vmas affected by unmapping the range in question, we | |
1354 | * can't efficiently keep all vmas in step with mapping->truncate_count: | |
1355 | * so instead reset them all whenever it wraps back to 0 (then go to 1). | |
1356 | * mapping->truncate_count and vma->vm_truncate_count are protected by | |
1357 | * i_mmap_lock. | |
1358 | * | |
1359 | * In order to make forward progress despite repeatedly restarting some | |
ee39b37b | 1360 | * large vma, note the restart_addr from unmap_vmas when it breaks out: |
1da177e4 LT |
1361 | * and restart from that address when we reach that vma again. It might |
1362 | * have been split or merged, shrunk or extended, but never shifted: so | |
1363 | * restart_addr remains valid so long as it remains in the vma's range. | |
1364 | * unmap_mapping_range forces truncate_count to leap over page-aligned | |
1365 | * values so we can save vma's restart_addr in its truncate_count field. | |
1366 | */ | |
1367 | #define is_restart_addr(truncate_count) (!((truncate_count) & ~PAGE_MASK)) | |
1368 | ||
1369 | static void reset_vma_truncate_counts(struct address_space *mapping) | |
1370 | { | |
1371 | struct vm_area_struct *vma; | |
1372 | struct prio_tree_iter iter; | |
1373 | ||
1374 | vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, 0, ULONG_MAX) | |
1375 | vma->vm_truncate_count = 0; | |
1376 | list_for_each_entry(vma, &mapping->i_mmap_nonlinear, shared.vm_set.list) | |
1377 | vma->vm_truncate_count = 0; | |
1378 | } | |
1379 | ||
1380 | static int unmap_mapping_range_vma(struct vm_area_struct *vma, | |
1381 | unsigned long start_addr, unsigned long end_addr, | |
1382 | struct zap_details *details) | |
1383 | { | |
1384 | unsigned long restart_addr; | |
1385 | int need_break; | |
1386 | ||
1387 | again: | |
1388 | restart_addr = vma->vm_truncate_count; | |
1389 | if (is_restart_addr(restart_addr) && start_addr < restart_addr) { | |
1390 | start_addr = restart_addr; | |
1391 | if (start_addr >= end_addr) { | |
1392 | /* Top of vma has been split off since last time */ | |
1393 | vma->vm_truncate_count = details->truncate_count; | |
1394 | return 0; | |
1395 | } | |
1396 | } | |
1397 | ||
ee39b37b HD |
1398 | restart_addr = zap_page_range(vma, start_addr, |
1399 | end_addr - start_addr, details); | |
1da177e4 LT |
1400 | need_break = need_resched() || |
1401 | need_lockbreak(details->i_mmap_lock); | |
1402 | ||
ee39b37b | 1403 | if (restart_addr >= end_addr) { |
1da177e4 LT |
1404 | /* We have now completed this vma: mark it so */ |
1405 | vma->vm_truncate_count = details->truncate_count; | |
1406 | if (!need_break) | |
1407 | return 0; | |
1408 | } else { | |
1409 | /* Note restart_addr in vma's truncate_count field */ | |
ee39b37b | 1410 | vma->vm_truncate_count = restart_addr; |
1da177e4 LT |
1411 | if (!need_break) |
1412 | goto again; | |
1413 | } | |
1414 | ||
1415 | spin_unlock(details->i_mmap_lock); | |
1416 | cond_resched(); | |
1417 | spin_lock(details->i_mmap_lock); | |
1418 | return -EINTR; | |
1419 | } | |
1420 | ||
1421 | static inline void unmap_mapping_range_tree(struct prio_tree_root *root, | |
1422 | struct zap_details *details) | |
1423 | { | |
1424 | struct vm_area_struct *vma; | |
1425 | struct prio_tree_iter iter; | |
1426 | pgoff_t vba, vea, zba, zea; | |
1427 | ||
1428 | restart: | |
1429 | vma_prio_tree_foreach(vma, &iter, root, | |
1430 | details->first_index, details->last_index) { | |
1431 | /* Skip quickly over those we have already dealt with */ | |
1432 | if (vma->vm_truncate_count == details->truncate_count) | |
1433 | continue; | |
1434 | ||
1435 | vba = vma->vm_pgoff; | |
1436 | vea = vba + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) - 1; | |
1437 | /* Assume for now that PAGE_CACHE_SHIFT == PAGE_SHIFT */ | |
1438 | zba = details->first_index; | |
1439 | if (zba < vba) | |
1440 | zba = vba; | |
1441 | zea = details->last_index; | |
1442 | if (zea > vea) | |
1443 | zea = vea; | |
1444 | ||
1445 | if (unmap_mapping_range_vma(vma, | |
1446 | ((zba - vba) << PAGE_SHIFT) + vma->vm_start, | |
1447 | ((zea - vba + 1) << PAGE_SHIFT) + vma->vm_start, | |
1448 | details) < 0) | |
1449 | goto restart; | |
1450 | } | |
1451 | } | |
1452 | ||
1453 | static inline void unmap_mapping_range_list(struct list_head *head, | |
1454 | struct zap_details *details) | |
1455 | { | |
1456 | struct vm_area_struct *vma; | |
1457 | ||
1458 | /* | |
1459 | * In nonlinear VMAs there is no correspondence between virtual address | |
1460 | * offset and file offset. So we must perform an exhaustive search | |
1461 | * across *all* the pages in each nonlinear VMA, not just the pages | |
1462 | * whose virtual address lies outside the file truncation point. | |
1463 | */ | |
1464 | restart: | |
1465 | list_for_each_entry(vma, head, shared.vm_set.list) { | |
1466 | /* Skip quickly over those we have already dealt with */ | |
1467 | if (vma->vm_truncate_count == details->truncate_count) | |
1468 | continue; | |
1469 | details->nonlinear_vma = vma; | |
1470 | if (unmap_mapping_range_vma(vma, vma->vm_start, | |
1471 | vma->vm_end, details) < 0) | |
1472 | goto restart; | |
1473 | } | |
1474 | } | |
1475 | ||
1476 | /** | |
1477 | * unmap_mapping_range - unmap the portion of all mmaps | |
1478 | * in the specified address_space corresponding to the specified | |
1479 | * page range in the underlying file. | |
3d41088f | 1480 | * @mapping: the address space containing mmaps to be unmapped. |
1da177e4 LT |
1481 | * @holebegin: byte in first page to unmap, relative to the start of |
1482 | * the underlying file. This will be rounded down to a PAGE_SIZE | |
1483 | * boundary. Note that this is different from vmtruncate(), which | |
1484 | * must keep the partial page. In contrast, we must get rid of | |
1485 | * partial pages. | |
1486 | * @holelen: size of prospective hole in bytes. This will be rounded | |
1487 | * up to a PAGE_SIZE boundary. A holelen of zero truncates to the | |
1488 | * end of the file. | |
1489 | * @even_cows: 1 when truncating a file, unmap even private COWed pages; | |
1490 | * but 0 when invalidating pagecache, don't throw away private data. | |
1491 | */ | |
1492 | void unmap_mapping_range(struct address_space *mapping, | |
1493 | loff_t const holebegin, loff_t const holelen, int even_cows) | |
1494 | { | |
1495 | struct zap_details details; | |
1496 | pgoff_t hba = holebegin >> PAGE_SHIFT; | |
1497 | pgoff_t hlen = (holelen + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
1498 | ||
1499 | /* Check for overflow. */ | |
1500 | if (sizeof(holelen) > sizeof(hlen)) { | |
1501 | long long holeend = | |
1502 | (holebegin + holelen + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
1503 | if (holeend & ~(long long)ULONG_MAX) | |
1504 | hlen = ULONG_MAX - hba + 1; | |
1505 | } | |
1506 | ||
1507 | details.check_mapping = even_cows? NULL: mapping; | |
1508 | details.nonlinear_vma = NULL; | |
1509 | details.first_index = hba; | |
1510 | details.last_index = hba + hlen - 1; | |
1511 | if (details.last_index < details.first_index) | |
1512 | details.last_index = ULONG_MAX; | |
1513 | details.i_mmap_lock = &mapping->i_mmap_lock; | |
1514 | ||
1515 | spin_lock(&mapping->i_mmap_lock); | |
1516 | ||
1517 | /* serialize i_size write against truncate_count write */ | |
1518 | smp_wmb(); | |
1519 | /* Protect against page faults, and endless unmapping loops */ | |
1520 | mapping->truncate_count++; | |
1521 | /* | |
1522 | * For archs where spin_lock has inclusive semantics like ia64 | |
1523 | * this smp_mb() will prevent to read pagetable contents | |
1524 | * before the truncate_count increment is visible to | |
1525 | * other cpus. | |
1526 | */ | |
1527 | smp_mb(); | |
1528 | if (unlikely(is_restart_addr(mapping->truncate_count))) { | |
1529 | if (mapping->truncate_count == 0) | |
1530 | reset_vma_truncate_counts(mapping); | |
1531 | mapping->truncate_count++; | |
1532 | } | |
1533 | details.truncate_count = mapping->truncate_count; | |
1534 | ||
1535 | if (unlikely(!prio_tree_empty(&mapping->i_mmap))) | |
1536 | unmap_mapping_range_tree(&mapping->i_mmap, &details); | |
1537 | if (unlikely(!list_empty(&mapping->i_mmap_nonlinear))) | |
1538 | unmap_mapping_range_list(&mapping->i_mmap_nonlinear, &details); | |
1539 | spin_unlock(&mapping->i_mmap_lock); | |
1540 | } | |
1541 | EXPORT_SYMBOL(unmap_mapping_range); | |
1542 | ||
1543 | /* | |
1544 | * Handle all mappings that got truncated by a "truncate()" | |
1545 | * system call. | |
1546 | * | |
1547 | * NOTE! We have to be ready to update the memory sharing | |
1548 | * between the file and the memory map for a potential last | |
1549 | * incomplete page. Ugly, but necessary. | |
1550 | */ | |
1551 | int vmtruncate(struct inode * inode, loff_t offset) | |
1552 | { | |
1553 | struct address_space *mapping = inode->i_mapping; | |
1554 | unsigned long limit; | |
1555 | ||
1556 | if (inode->i_size < offset) | |
1557 | goto do_expand; | |
1558 | /* | |
1559 | * truncation of in-use swapfiles is disallowed - it would cause | |
1560 | * subsequent swapout to scribble on the now-freed blocks. | |
1561 | */ | |
1562 | if (IS_SWAPFILE(inode)) | |
1563 | goto out_busy; | |
1564 | i_size_write(inode, offset); | |
1565 | unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1); | |
1566 | truncate_inode_pages(mapping, offset); | |
1567 | goto out_truncate; | |
1568 | ||
1569 | do_expand: | |
1570 | limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur; | |
1571 | if (limit != RLIM_INFINITY && offset > limit) | |
1572 | goto out_sig; | |
1573 | if (offset > inode->i_sb->s_maxbytes) | |
1574 | goto out_big; | |
1575 | i_size_write(inode, offset); | |
1576 | ||
1577 | out_truncate: | |
1578 | if (inode->i_op && inode->i_op->truncate) | |
1579 | inode->i_op->truncate(inode); | |
1580 | return 0; | |
1581 | out_sig: | |
1582 | send_sig(SIGXFSZ, current, 0); | |
1583 | out_big: | |
1584 | return -EFBIG; | |
1585 | out_busy: | |
1586 | return -ETXTBSY; | |
1587 | } | |
1588 | ||
1589 | EXPORT_SYMBOL(vmtruncate); | |
1590 | ||
1591 | /* | |
1592 | * Primitive swap readahead code. We simply read an aligned block of | |
1593 | * (1 << page_cluster) entries in the swap area. This method is chosen | |
1594 | * because it doesn't cost us any seek time. We also make sure to queue | |
1595 | * the 'original' request together with the readahead ones... | |
1596 | * | |
1597 | * This has been extended to use the NUMA policies from the mm triggering | |
1598 | * the readahead. | |
1599 | * | |
1600 | * Caller must hold down_read on the vma->vm_mm if vma is not NULL. | |
1601 | */ | |
1602 | void swapin_readahead(swp_entry_t entry, unsigned long addr,struct vm_area_struct *vma) | |
1603 | { | |
1604 | #ifdef CONFIG_NUMA | |
1605 | struct vm_area_struct *next_vma = vma ? vma->vm_next : NULL; | |
1606 | #endif | |
1607 | int i, num; | |
1608 | struct page *new_page; | |
1609 | unsigned long offset; | |
1610 | ||
1611 | /* | |
1612 | * Get the number of handles we should do readahead io to. | |
1613 | */ | |
1614 | num = valid_swaphandles(entry, &offset); | |
1615 | for (i = 0; i < num; offset++, i++) { | |
1616 | /* Ok, do the async read-ahead now */ | |
1617 | new_page = read_swap_cache_async(swp_entry(swp_type(entry), | |
1618 | offset), vma, addr); | |
1619 | if (!new_page) | |
1620 | break; | |
1621 | page_cache_release(new_page); | |
1622 | #ifdef CONFIG_NUMA | |
1623 | /* | |
1624 | * Find the next applicable VMA for the NUMA policy. | |
1625 | */ | |
1626 | addr += PAGE_SIZE; | |
1627 | if (addr == 0) | |
1628 | vma = NULL; | |
1629 | if (vma) { | |
1630 | if (addr >= vma->vm_end) { | |
1631 | vma = next_vma; | |
1632 | next_vma = vma ? vma->vm_next : NULL; | |
1633 | } | |
1634 | if (vma && addr < vma->vm_start) | |
1635 | vma = NULL; | |
1636 | } else { | |
1637 | if (next_vma && addr >= next_vma->vm_start) { | |
1638 | vma = next_vma; | |
1639 | next_vma = vma->vm_next; | |
1640 | } | |
1641 | } | |
1642 | #endif | |
1643 | } | |
1644 | lru_add_drain(); /* Push any new pages onto the LRU now */ | |
1645 | } | |
1646 | ||
1647 | /* | |
8f4e2101 HD |
1648 | * We enter with non-exclusive mmap_sem (to exclude vma changes, |
1649 | * but allow concurrent faults), and pte mapped but not yet locked. | |
1650 | * We return with mmap_sem still held, but pte unmapped and unlocked. | |
1da177e4 | 1651 | */ |
65500d23 HD |
1652 | static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma, |
1653 | unsigned long address, pte_t *page_table, pmd_t *pmd, | |
1654 | int write_access, pte_t orig_pte) | |
1da177e4 | 1655 | { |
8f4e2101 | 1656 | spinlock_t *ptl; |
1da177e4 | 1657 | struct page *page; |
65500d23 | 1658 | swp_entry_t entry; |
1da177e4 LT |
1659 | pte_t pte; |
1660 | int ret = VM_FAULT_MINOR; | |
1661 | ||
4c21e2f2 | 1662 | if (!pte_unmap_same(mm, pmd, page_table, orig_pte)) |
8f4e2101 | 1663 | goto out; |
65500d23 HD |
1664 | |
1665 | entry = pte_to_swp_entry(orig_pte); | |
1da177e4 LT |
1666 | page = lookup_swap_cache(entry); |
1667 | if (!page) { | |
1668 | swapin_readahead(entry, address, vma); | |
1669 | page = read_swap_cache_async(entry, vma, address); | |
1670 | if (!page) { | |
1671 | /* | |
8f4e2101 HD |
1672 | * Back out if somebody else faulted in this pte |
1673 | * while we released the pte lock. | |
1da177e4 | 1674 | */ |
8f4e2101 | 1675 | page_table = pte_offset_map_lock(mm, pmd, address, &ptl); |
1da177e4 LT |
1676 | if (likely(pte_same(*page_table, orig_pte))) |
1677 | ret = VM_FAULT_OOM; | |
65500d23 | 1678 | goto unlock; |
1da177e4 LT |
1679 | } |
1680 | ||
1681 | /* Had to read the page from swap area: Major fault */ | |
1682 | ret = VM_FAULT_MAJOR; | |
1683 | inc_page_state(pgmajfault); | |
1684 | grab_swap_token(); | |
1685 | } | |
1686 | ||
1687 | mark_page_accessed(page); | |
1688 | lock_page(page); | |
1689 | ||
1690 | /* | |
8f4e2101 | 1691 | * Back out if somebody else already faulted in this pte. |
1da177e4 | 1692 | */ |
8f4e2101 | 1693 | page_table = pte_offset_map_lock(mm, pmd, address, &ptl); |
9e9bef07 | 1694 | if (unlikely(!pte_same(*page_table, orig_pte))) |
b8107480 | 1695 | goto out_nomap; |
b8107480 KK |
1696 | |
1697 | if (unlikely(!PageUptodate(page))) { | |
1698 | ret = VM_FAULT_SIGBUS; | |
1699 | goto out_nomap; | |
1da177e4 LT |
1700 | } |
1701 | ||
1702 | /* The page isn't present yet, go ahead with the fault. */ | |
1da177e4 | 1703 | |
4294621f | 1704 | inc_mm_counter(mm, anon_rss); |
1da177e4 LT |
1705 | pte = mk_pte(page, vma->vm_page_prot); |
1706 | if (write_access && can_share_swap_page(page)) { | |
1707 | pte = maybe_mkwrite(pte_mkdirty(pte), vma); | |
1708 | write_access = 0; | |
1709 | } | |
1da177e4 LT |
1710 | |
1711 | flush_icache_page(vma, page); | |
1712 | set_pte_at(mm, address, page_table, pte); | |
1713 | page_add_anon_rmap(page, vma, address); | |
1714 | ||
c475a8ab HD |
1715 | swap_free(entry); |
1716 | if (vm_swap_full()) | |
1717 | remove_exclusive_swap_page(page); | |
1718 | unlock_page(page); | |
1719 | ||
1da177e4 LT |
1720 | if (write_access) { |
1721 | if (do_wp_page(mm, vma, address, | |
8f4e2101 | 1722 | page_table, pmd, ptl, pte) == VM_FAULT_OOM) |
1da177e4 LT |
1723 | ret = VM_FAULT_OOM; |
1724 | goto out; | |
1725 | } | |
1726 | ||
1727 | /* No need to invalidate - it was non-present before */ | |
1728 | update_mmu_cache(vma, address, pte); | |
1729 | lazy_mmu_prot_update(pte); | |
65500d23 | 1730 | unlock: |
8f4e2101 | 1731 | pte_unmap_unlock(page_table, ptl); |
1da177e4 LT |
1732 | out: |
1733 | return ret; | |
b8107480 | 1734 | out_nomap: |
8f4e2101 | 1735 | pte_unmap_unlock(page_table, ptl); |
b8107480 KK |
1736 | unlock_page(page); |
1737 | page_cache_release(page); | |
65500d23 | 1738 | return ret; |
1da177e4 LT |
1739 | } |
1740 | ||
1741 | /* | |
8f4e2101 HD |
1742 | * We enter with non-exclusive mmap_sem (to exclude vma changes, |
1743 | * but allow concurrent faults), and pte mapped but not yet locked. | |
1744 | * We return with mmap_sem still held, but pte unmapped and unlocked. | |
1da177e4 | 1745 | */ |
65500d23 HD |
1746 | static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, |
1747 | unsigned long address, pte_t *page_table, pmd_t *pmd, | |
1748 | int write_access) | |
1da177e4 | 1749 | { |
8f4e2101 HD |
1750 | struct page *page; |
1751 | spinlock_t *ptl; | |
1da177e4 | 1752 | pte_t entry; |
1da177e4 | 1753 | |
1da177e4 LT |
1754 | if (write_access) { |
1755 | /* Allocate our own private page. */ | |
1756 | pte_unmap(page_table); | |
1da177e4 LT |
1757 | |
1758 | if (unlikely(anon_vma_prepare(vma))) | |
65500d23 HD |
1759 | goto oom; |
1760 | page = alloc_zeroed_user_highpage(vma, address); | |
1da177e4 | 1761 | if (!page) |
65500d23 | 1762 | goto oom; |
1da177e4 | 1763 | |
65500d23 HD |
1764 | entry = mk_pte(page, vma->vm_page_prot); |
1765 | entry = maybe_mkwrite(pte_mkdirty(entry), vma); | |
8f4e2101 HD |
1766 | |
1767 | page_table = pte_offset_map_lock(mm, pmd, address, &ptl); | |
1768 | if (!pte_none(*page_table)) | |
1769 | goto release; | |
1770 | inc_mm_counter(mm, anon_rss); | |
1da177e4 LT |
1771 | lru_cache_add_active(page); |
1772 | SetPageReferenced(page); | |
65500d23 | 1773 | page_add_anon_rmap(page, vma, address); |
b5810039 | 1774 | } else { |
8f4e2101 HD |
1775 | /* Map the ZERO_PAGE - vm_page_prot is readonly */ |
1776 | page = ZERO_PAGE(address); | |
1777 | page_cache_get(page); | |
1778 | entry = mk_pte(page, vma->vm_page_prot); | |
1779 | ||
4c21e2f2 | 1780 | ptl = pte_lockptr(mm, pmd); |
8f4e2101 HD |
1781 | spin_lock(ptl); |
1782 | if (!pte_none(*page_table)) | |
1783 | goto release; | |
b5810039 NP |
1784 | inc_mm_counter(mm, file_rss); |
1785 | page_add_file_rmap(page); | |
1da177e4 LT |
1786 | } |
1787 | ||
65500d23 | 1788 | set_pte_at(mm, address, page_table, entry); |
1da177e4 LT |
1789 | |
1790 | /* No need to invalidate - it was non-present before */ | |
65500d23 | 1791 | update_mmu_cache(vma, address, entry); |
1da177e4 | 1792 | lazy_mmu_prot_update(entry); |
65500d23 | 1793 | unlock: |
8f4e2101 | 1794 | pte_unmap_unlock(page_table, ptl); |
1da177e4 | 1795 | return VM_FAULT_MINOR; |
8f4e2101 HD |
1796 | release: |
1797 | page_cache_release(page); | |
1798 | goto unlock; | |
65500d23 | 1799 | oom: |
1da177e4 LT |
1800 | return VM_FAULT_OOM; |
1801 | } | |
1802 | ||
1803 | /* | |
1804 | * do_no_page() tries to create a new page mapping. It aggressively | |
1805 | * tries to share with existing pages, but makes a separate copy if | |
1806 | * the "write_access" parameter is true in order to avoid the next | |
1807 | * page fault. | |
1808 | * | |
1809 | * As this is called only for pages that do not currently exist, we | |
1810 | * do not need to flush old virtual caches or the TLB. | |
1811 | * | |
8f4e2101 HD |
1812 | * We enter with non-exclusive mmap_sem (to exclude vma changes, |
1813 | * but allow concurrent faults), and pte mapped but not yet locked. | |
1814 | * We return with mmap_sem still held, but pte unmapped and unlocked. | |
1da177e4 | 1815 | */ |
65500d23 HD |
1816 | static int do_no_page(struct mm_struct *mm, struct vm_area_struct *vma, |
1817 | unsigned long address, pte_t *page_table, pmd_t *pmd, | |
1818 | int write_access) | |
1da177e4 | 1819 | { |
8f4e2101 | 1820 | spinlock_t *ptl; |
65500d23 | 1821 | struct page *new_page; |
1da177e4 LT |
1822 | struct address_space *mapping = NULL; |
1823 | pte_t entry; | |
1824 | unsigned int sequence = 0; | |
1825 | int ret = VM_FAULT_MINOR; | |
1826 | int anon = 0; | |
1827 | ||
1da177e4 | 1828 | pte_unmap(page_table); |
1da177e4 LT |
1829 | |
1830 | if (vma->vm_file) { | |
1831 | mapping = vma->vm_file->f_mapping; | |
1832 | sequence = mapping->truncate_count; | |
1833 | smp_rmb(); /* serializes i_size against truncate_count */ | |
1834 | } | |
1835 | retry: | |
1da177e4 LT |
1836 | new_page = vma->vm_ops->nopage(vma, address & PAGE_MASK, &ret); |
1837 | /* | |
1838 | * No smp_rmb is needed here as long as there's a full | |
1839 | * spin_lock/unlock sequence inside the ->nopage callback | |
1840 | * (for the pagecache lookup) that acts as an implicit | |
1841 | * smp_mb() and prevents the i_size read to happen | |
1842 | * after the next truncate_count read. | |
1843 | */ | |
1844 | ||
1845 | /* no page was available -- either SIGBUS or OOM */ | |
1846 | if (new_page == NOPAGE_SIGBUS) | |
1847 | return VM_FAULT_SIGBUS; | |
1848 | if (new_page == NOPAGE_OOM) | |
1849 | return VM_FAULT_OOM; | |
1850 | ||
1851 | /* | |
1852 | * Should we do an early C-O-W break? | |
1853 | */ | |
1854 | if (write_access && !(vma->vm_flags & VM_SHARED)) { | |
1855 | struct page *page; | |
1856 | ||
1857 | if (unlikely(anon_vma_prepare(vma))) | |
1858 | goto oom; | |
1859 | page = alloc_page_vma(GFP_HIGHUSER, vma, address); | |
1860 | if (!page) | |
1861 | goto oom; | |
1862 | copy_user_highpage(page, new_page, address); | |
1863 | page_cache_release(new_page); | |
1864 | new_page = page; | |
1865 | anon = 1; | |
1866 | } | |
1867 | ||
8f4e2101 | 1868 | page_table = pte_offset_map_lock(mm, pmd, address, &ptl); |
1da177e4 LT |
1869 | /* |
1870 | * For a file-backed vma, someone could have truncated or otherwise | |
1871 | * invalidated this page. If unmap_mapping_range got called, | |
1872 | * retry getting the page. | |
1873 | */ | |
1874 | if (mapping && unlikely(sequence != mapping->truncate_count)) { | |
8f4e2101 | 1875 | pte_unmap_unlock(page_table, ptl); |
1da177e4 | 1876 | page_cache_release(new_page); |
65500d23 HD |
1877 | cond_resched(); |
1878 | sequence = mapping->truncate_count; | |
1879 | smp_rmb(); | |
1da177e4 LT |
1880 | goto retry; |
1881 | } | |
1da177e4 LT |
1882 | |
1883 | /* | |
1884 | * This silly early PAGE_DIRTY setting removes a race | |
1885 | * due to the bad i386 page protection. But it's valid | |
1886 | * for other architectures too. | |
1887 | * | |
1888 | * Note that if write_access is true, we either now have | |
1889 | * an exclusive copy of the page, or this is a shared mapping, | |
1890 | * so we can make it writable and dirty to avoid having to | |
1891 | * handle that later. | |
1892 | */ | |
1893 | /* Only go through if we didn't race with anybody else... */ | |
1894 | if (pte_none(*page_table)) { | |
1da177e4 LT |
1895 | flush_icache_page(vma, new_page); |
1896 | entry = mk_pte(new_page, vma->vm_page_prot); | |
1897 | if (write_access) | |
1898 | entry = maybe_mkwrite(pte_mkdirty(entry), vma); | |
1899 | set_pte_at(mm, address, page_table, entry); | |
1900 | if (anon) { | |
4294621f | 1901 | inc_mm_counter(mm, anon_rss); |
1da177e4 LT |
1902 | lru_cache_add_active(new_page); |
1903 | page_add_anon_rmap(new_page, vma, address); | |
b5810039 | 1904 | } else if (!(vma->vm_flags & VM_RESERVED)) { |
4294621f | 1905 | inc_mm_counter(mm, file_rss); |
1da177e4 | 1906 | page_add_file_rmap(new_page); |
4294621f | 1907 | } |
1da177e4 LT |
1908 | } else { |
1909 | /* One of our sibling threads was faster, back out. */ | |
1da177e4 | 1910 | page_cache_release(new_page); |
65500d23 | 1911 | goto unlock; |
1da177e4 LT |
1912 | } |
1913 | ||
1914 | /* no need to invalidate: a not-present page shouldn't be cached */ | |
1915 | update_mmu_cache(vma, address, entry); | |
1916 | lazy_mmu_prot_update(entry); | |
65500d23 | 1917 | unlock: |
8f4e2101 | 1918 | pte_unmap_unlock(page_table, ptl); |
1da177e4 LT |
1919 | return ret; |
1920 | oom: | |
1921 | page_cache_release(new_page); | |
65500d23 | 1922 | return VM_FAULT_OOM; |
1da177e4 LT |
1923 | } |
1924 | ||
1925 | /* | |
1926 | * Fault of a previously existing named mapping. Repopulate the pte | |
1927 | * from the encoded file_pte if possible. This enables swappable | |
1928 | * nonlinear vmas. | |
8f4e2101 HD |
1929 | * |
1930 | * We enter with non-exclusive mmap_sem (to exclude vma changes, | |
1931 | * but allow concurrent faults), and pte mapped but not yet locked. | |
1932 | * We return with mmap_sem still held, but pte unmapped and unlocked. | |
1da177e4 | 1933 | */ |
65500d23 HD |
1934 | static int do_file_page(struct mm_struct *mm, struct vm_area_struct *vma, |
1935 | unsigned long address, pte_t *page_table, pmd_t *pmd, | |
1936 | int write_access, pte_t orig_pte) | |
1da177e4 | 1937 | { |
65500d23 | 1938 | pgoff_t pgoff; |
1da177e4 LT |
1939 | int err; |
1940 | ||
4c21e2f2 | 1941 | if (!pte_unmap_same(mm, pmd, page_table, orig_pte)) |
8f4e2101 | 1942 | return VM_FAULT_MINOR; |
1da177e4 | 1943 | |
65500d23 HD |
1944 | if (unlikely(!(vma->vm_flags & VM_NONLINEAR))) { |
1945 | /* | |
1946 | * Page table corrupted: show pte and kill process. | |
1947 | */ | |
b5810039 | 1948 | print_bad_pte(vma, orig_pte, address); |
65500d23 HD |
1949 | return VM_FAULT_OOM; |
1950 | } | |
1951 | /* We can then assume vm->vm_ops && vma->vm_ops->populate */ | |
1952 | ||
1953 | pgoff = pte_to_pgoff(orig_pte); | |
1954 | err = vma->vm_ops->populate(vma, address & PAGE_MASK, PAGE_SIZE, | |
1955 | vma->vm_page_prot, pgoff, 0); | |
1da177e4 LT |
1956 | if (err == -ENOMEM) |
1957 | return VM_FAULT_OOM; | |
1958 | if (err) | |
1959 | return VM_FAULT_SIGBUS; | |
1960 | return VM_FAULT_MAJOR; | |
1961 | } | |
1962 | ||
1963 | /* | |
1964 | * These routines also need to handle stuff like marking pages dirty | |
1965 | * and/or accessed for architectures that don't do it in hardware (most | |
1966 | * RISC architectures). The early dirtying is also good on the i386. | |
1967 | * | |
1968 | * There is also a hook called "update_mmu_cache()" that architectures | |
1969 | * with external mmu caches can use to update those (ie the Sparc or | |
1970 | * PowerPC hashed page tables that act as extended TLBs). | |
1971 | * | |
c74df32c HD |
1972 | * We enter with non-exclusive mmap_sem (to exclude vma changes, |
1973 | * but allow concurrent faults), and pte mapped but not yet locked. | |
1974 | * We return with mmap_sem still held, but pte unmapped and unlocked. | |
1da177e4 LT |
1975 | */ |
1976 | static inline int handle_pte_fault(struct mm_struct *mm, | |
65500d23 HD |
1977 | struct vm_area_struct *vma, unsigned long address, |
1978 | pte_t *pte, pmd_t *pmd, int write_access) | |
1da177e4 LT |
1979 | { |
1980 | pte_t entry; | |
8f4e2101 | 1981 | spinlock_t *ptl; |
1da177e4 LT |
1982 | |
1983 | entry = *pte; | |
1984 | if (!pte_present(entry)) { | |
65500d23 HD |
1985 | if (pte_none(entry)) { |
1986 | if (!vma->vm_ops || !vma->vm_ops->nopage) | |
1987 | return do_anonymous_page(mm, vma, address, | |
1988 | pte, pmd, write_access); | |
1989 | return do_no_page(mm, vma, address, | |
1990 | pte, pmd, write_access); | |
1991 | } | |
1da177e4 | 1992 | if (pte_file(entry)) |
65500d23 HD |
1993 | return do_file_page(mm, vma, address, |
1994 | pte, pmd, write_access, entry); | |
1995 | return do_swap_page(mm, vma, address, | |
1996 | pte, pmd, write_access, entry); | |
1da177e4 LT |
1997 | } |
1998 | ||
4c21e2f2 | 1999 | ptl = pte_lockptr(mm, pmd); |
8f4e2101 HD |
2000 | spin_lock(ptl); |
2001 | if (unlikely(!pte_same(*pte, entry))) | |
2002 | goto unlock; | |
1da177e4 LT |
2003 | if (write_access) { |
2004 | if (!pte_write(entry)) | |
8f4e2101 HD |
2005 | return do_wp_page(mm, vma, address, |
2006 | pte, pmd, ptl, entry); | |
1da177e4 LT |
2007 | entry = pte_mkdirty(entry); |
2008 | } | |
2009 | entry = pte_mkyoung(entry); | |
2010 | ptep_set_access_flags(vma, address, pte, entry, write_access); | |
2011 | update_mmu_cache(vma, address, entry); | |
2012 | lazy_mmu_prot_update(entry); | |
8f4e2101 HD |
2013 | unlock: |
2014 | pte_unmap_unlock(pte, ptl); | |
1da177e4 LT |
2015 | return VM_FAULT_MINOR; |
2016 | } | |
2017 | ||
2018 | /* | |
2019 | * By the time we get here, we already hold the mm semaphore | |
2020 | */ | |
65500d23 | 2021 | int __handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
1da177e4 LT |
2022 | unsigned long address, int write_access) |
2023 | { | |
2024 | pgd_t *pgd; | |
2025 | pud_t *pud; | |
2026 | pmd_t *pmd; | |
2027 | pte_t *pte; | |
2028 | ||
2029 | __set_current_state(TASK_RUNNING); | |
2030 | ||
2031 | inc_page_state(pgfault); | |
2032 | ||
ac9b9c66 HD |
2033 | if (unlikely(is_vm_hugetlb_page(vma))) |
2034 | return hugetlb_fault(mm, vma, address, write_access); | |
1da177e4 | 2035 | |
1da177e4 | 2036 | pgd = pgd_offset(mm, address); |
1da177e4 LT |
2037 | pud = pud_alloc(mm, pgd, address); |
2038 | if (!pud) | |
c74df32c | 2039 | return VM_FAULT_OOM; |
1da177e4 LT |
2040 | pmd = pmd_alloc(mm, pud, address); |
2041 | if (!pmd) | |
c74df32c | 2042 | return VM_FAULT_OOM; |
1da177e4 LT |
2043 | pte = pte_alloc_map(mm, pmd, address); |
2044 | if (!pte) | |
c74df32c | 2045 | return VM_FAULT_OOM; |
1da177e4 | 2046 | |
c74df32c | 2047 | return handle_pte_fault(mm, vma, address, pte, pmd, write_access); |
1da177e4 LT |
2048 | } |
2049 | ||
2050 | #ifndef __PAGETABLE_PUD_FOLDED | |
2051 | /* | |
2052 | * Allocate page upper directory. | |
872fec16 | 2053 | * We've already handled the fast-path in-line. |
1da177e4 | 2054 | */ |
1bb3630e | 2055 | int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address) |
1da177e4 | 2056 | { |
c74df32c HD |
2057 | pud_t *new = pud_alloc_one(mm, address); |
2058 | if (!new) | |
1bb3630e | 2059 | return -ENOMEM; |
1da177e4 | 2060 | |
872fec16 | 2061 | spin_lock(&mm->page_table_lock); |
1bb3630e | 2062 | if (pgd_present(*pgd)) /* Another has populated it */ |
1da177e4 | 2063 | pud_free(new); |
1bb3630e HD |
2064 | else |
2065 | pgd_populate(mm, pgd, new); | |
c74df32c | 2066 | spin_unlock(&mm->page_table_lock); |
1bb3630e | 2067 | return 0; |
1da177e4 LT |
2068 | } |
2069 | #endif /* __PAGETABLE_PUD_FOLDED */ | |
2070 | ||
2071 | #ifndef __PAGETABLE_PMD_FOLDED | |
2072 | /* | |
2073 | * Allocate page middle directory. | |
872fec16 | 2074 | * We've already handled the fast-path in-line. |
1da177e4 | 2075 | */ |
1bb3630e | 2076 | int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address) |
1da177e4 | 2077 | { |
c74df32c HD |
2078 | pmd_t *new = pmd_alloc_one(mm, address); |
2079 | if (!new) | |
1bb3630e | 2080 | return -ENOMEM; |
1da177e4 | 2081 | |
872fec16 | 2082 | spin_lock(&mm->page_table_lock); |
1da177e4 | 2083 | #ifndef __ARCH_HAS_4LEVEL_HACK |
1bb3630e | 2084 | if (pud_present(*pud)) /* Another has populated it */ |
1da177e4 | 2085 | pmd_free(new); |
1bb3630e HD |
2086 | else |
2087 | pud_populate(mm, pud, new); | |
1da177e4 | 2088 | #else |
1bb3630e | 2089 | if (pgd_present(*pud)) /* Another has populated it */ |
1da177e4 | 2090 | pmd_free(new); |
1bb3630e HD |
2091 | else |
2092 | pgd_populate(mm, pud, new); | |
1da177e4 | 2093 | #endif /* __ARCH_HAS_4LEVEL_HACK */ |
c74df32c | 2094 | spin_unlock(&mm->page_table_lock); |
1bb3630e | 2095 | return 0; |
1da177e4 LT |
2096 | } |
2097 | #endif /* __PAGETABLE_PMD_FOLDED */ | |
2098 | ||
2099 | int make_pages_present(unsigned long addr, unsigned long end) | |
2100 | { | |
2101 | int ret, len, write; | |
2102 | struct vm_area_struct * vma; | |
2103 | ||
2104 | vma = find_vma(current->mm, addr); | |
2105 | if (!vma) | |
2106 | return -1; | |
2107 | write = (vma->vm_flags & VM_WRITE) != 0; | |
2108 | if (addr >= end) | |
2109 | BUG(); | |
2110 | if (end > vma->vm_end) | |
2111 | BUG(); | |
2112 | len = (end+PAGE_SIZE-1)/PAGE_SIZE-addr/PAGE_SIZE; | |
2113 | ret = get_user_pages(current, current->mm, addr, | |
2114 | len, write, 0, NULL, NULL); | |
2115 | if (ret < 0) | |
2116 | return ret; | |
2117 | return ret == len ? 0 : -1; | |
2118 | } | |
2119 | ||
2120 | /* | |
2121 | * Map a vmalloc()-space virtual address to the physical page. | |
2122 | */ | |
2123 | struct page * vmalloc_to_page(void * vmalloc_addr) | |
2124 | { | |
2125 | unsigned long addr = (unsigned long) vmalloc_addr; | |
2126 | struct page *page = NULL; | |
2127 | pgd_t *pgd = pgd_offset_k(addr); | |
2128 | pud_t *pud; | |
2129 | pmd_t *pmd; | |
2130 | pte_t *ptep, pte; | |
2131 | ||
2132 | if (!pgd_none(*pgd)) { | |
2133 | pud = pud_offset(pgd, addr); | |
2134 | if (!pud_none(*pud)) { | |
2135 | pmd = pmd_offset(pud, addr); | |
2136 | if (!pmd_none(*pmd)) { | |
2137 | ptep = pte_offset_map(pmd, addr); | |
2138 | pte = *ptep; | |
2139 | if (pte_present(pte)) | |
2140 | page = pte_page(pte); | |
2141 | pte_unmap(ptep); | |
2142 | } | |
2143 | } | |
2144 | } | |
2145 | return page; | |
2146 | } | |
2147 | ||
2148 | EXPORT_SYMBOL(vmalloc_to_page); | |
2149 | ||
2150 | /* | |
2151 | * Map a vmalloc()-space virtual address to the physical page frame number. | |
2152 | */ | |
2153 | unsigned long vmalloc_to_pfn(void * vmalloc_addr) | |
2154 | { | |
2155 | return page_to_pfn(vmalloc_to_page(vmalloc_addr)); | |
2156 | } | |
2157 | ||
2158 | EXPORT_SYMBOL(vmalloc_to_pfn); | |
2159 | ||
1da177e4 LT |
2160 | #if !defined(__HAVE_ARCH_GATE_AREA) |
2161 | ||
2162 | #if defined(AT_SYSINFO_EHDR) | |
5ce7852c | 2163 | static struct vm_area_struct gate_vma; |
1da177e4 LT |
2164 | |
2165 | static int __init gate_vma_init(void) | |
2166 | { | |
2167 | gate_vma.vm_mm = NULL; | |
2168 | gate_vma.vm_start = FIXADDR_USER_START; | |
2169 | gate_vma.vm_end = FIXADDR_USER_END; | |
2170 | gate_vma.vm_page_prot = PAGE_READONLY; | |
b5810039 | 2171 | gate_vma.vm_flags = VM_RESERVED; |
1da177e4 LT |
2172 | return 0; |
2173 | } | |
2174 | __initcall(gate_vma_init); | |
2175 | #endif | |
2176 | ||
2177 | struct vm_area_struct *get_gate_vma(struct task_struct *tsk) | |
2178 | { | |
2179 | #ifdef AT_SYSINFO_EHDR | |
2180 | return &gate_vma; | |
2181 | #else | |
2182 | return NULL; | |
2183 | #endif | |
2184 | } | |
2185 | ||
2186 | int in_gate_area_no_task(unsigned long addr) | |
2187 | { | |
2188 | #ifdef AT_SYSINFO_EHDR | |
2189 | if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END)) | |
2190 | return 1; | |
2191 | #endif | |
2192 | return 0; | |
2193 | } | |
2194 | ||
2195 | #endif /* __HAVE_ARCH_GATE_AREA */ |