Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * mm/mmap.c | |
3 | * | |
4 | * Written by obz. | |
5 | * | |
046c6884 | 6 | * Address space accounting code <alan@lxorguk.ukuu.org.uk> |
1da177e4 LT |
7 | */ |
8 | ||
9 | #include <linux/slab.h> | |
4af3c9cc | 10 | #include <linux/backing-dev.h> |
1da177e4 LT |
11 | #include <linux/mm.h> |
12 | #include <linux/shm.h> | |
13 | #include <linux/mman.h> | |
14 | #include <linux/pagemap.h> | |
15 | #include <linux/swap.h> | |
16 | #include <linux/syscalls.h> | |
c59ede7b | 17 | #include <linux/capability.h> |
1da177e4 LT |
18 | #include <linux/init.h> |
19 | #include <linux/file.h> | |
20 | #include <linux/fs.h> | |
21 | #include <linux/personality.h> | |
22 | #include <linux/security.h> | |
23 | #include <linux/hugetlb.h> | |
24 | #include <linux/profile.h> | |
25 | #include <linux/module.h> | |
26 | #include <linux/mount.h> | |
27 | #include <linux/mempolicy.h> | |
28 | #include <linux/rmap.h> | |
cddb8a5c | 29 | #include <linux/mmu_notifier.h> |
cdd6c482 | 30 | #include <linux/perf_event.h> |
1da177e4 LT |
31 | |
32 | #include <asm/uaccess.h> | |
33 | #include <asm/cacheflush.h> | |
34 | #include <asm/tlb.h> | |
d6dd61c8 | 35 | #include <asm/mmu_context.h> |
1da177e4 | 36 | |
42b77728 JB |
37 | #include "internal.h" |
38 | ||
3a459756 KK |
39 | #ifndef arch_mmap_check |
40 | #define arch_mmap_check(addr, len, flags) (0) | |
41 | #endif | |
42 | ||
08e7d9b5 MS |
43 | #ifndef arch_rebalance_pgtables |
44 | #define arch_rebalance_pgtables(addr, len) (addr) | |
45 | #endif | |
46 | ||
e0da382c HD |
47 | static void unmap_region(struct mm_struct *mm, |
48 | struct vm_area_struct *vma, struct vm_area_struct *prev, | |
49 | unsigned long start, unsigned long end); | |
50 | ||
1da177e4 LT |
51 | /* |
52 | * WARNING: the debugging will use recursive algorithms so never enable this | |
53 | * unless you know what you are doing. | |
54 | */ | |
55 | #undef DEBUG_MM_RB | |
56 | ||
57 | /* description of effects of mapping type and prot in current implementation. | |
58 | * this is due to the limited x86 page protection hardware. The expected | |
59 | * behavior is in parens: | |
60 | * | |
61 | * map_type prot | |
62 | * PROT_NONE PROT_READ PROT_WRITE PROT_EXEC | |
63 | * MAP_SHARED r: (no) no r: (yes) yes r: (no) yes r: (no) yes | |
64 | * w: (no) no w: (no) no w: (yes) yes w: (no) no | |
65 | * x: (no) no x: (no) yes x: (no) yes x: (yes) yes | |
66 | * | |
67 | * MAP_PRIVATE r: (no) no r: (yes) yes r: (no) yes r: (no) yes | |
68 | * w: (no) no w: (no) no w: (copy) copy w: (no) no | |
69 | * x: (no) no x: (no) yes x: (no) yes x: (yes) yes | |
70 | * | |
71 | */ | |
72 | pgprot_t protection_map[16] = { | |
73 | __P000, __P001, __P010, __P011, __P100, __P101, __P110, __P111, | |
74 | __S000, __S001, __S010, __S011, __S100, __S101, __S110, __S111 | |
75 | }; | |
76 | ||
804af2cf HD |
77 | pgprot_t vm_get_page_prot(unsigned long vm_flags) |
78 | { | |
b845f313 DK |
79 | return __pgprot(pgprot_val(protection_map[vm_flags & |
80 | (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]) | | |
81 | pgprot_val(arch_vm_get_page_prot(vm_flags))); | |
804af2cf HD |
82 | } |
83 | EXPORT_SYMBOL(vm_get_page_prot); | |
84 | ||
1da177e4 LT |
85 | int sysctl_overcommit_memory = OVERCOMMIT_GUESS; /* heuristic overcommit */ |
86 | int sysctl_overcommit_ratio = 50; /* default is 50% */ | |
c3d8c141 | 87 | int sysctl_max_map_count __read_mostly = DEFAULT_MAX_MAP_COUNT; |
00a62ce9 | 88 | struct percpu_counter vm_committed_as; |
1da177e4 LT |
89 | |
90 | /* | |
91 | * Check that a process has enough memory to allocate a new virtual | |
92 | * mapping. 0 means there is enough memory for the allocation to | |
93 | * succeed and -ENOMEM implies there is not. | |
94 | * | |
95 | * We currently support three overcommit policies, which are set via the | |
96 | * vm.overcommit_memory sysctl. See Documentation/vm/overcommit-accounting | |
97 | * | |
98 | * Strict overcommit modes added 2002 Feb 26 by Alan Cox. | |
99 | * Additional code 2002 Jul 20 by Robert Love. | |
100 | * | |
101 | * cap_sys_admin is 1 if the process has admin privileges, 0 otherwise. | |
102 | * | |
103 | * Note this is a helper function intended to be used by LSMs which | |
104 | * wish to use this logic. | |
105 | */ | |
34b4e4aa | 106 | int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin) |
1da177e4 LT |
107 | { |
108 | unsigned long free, allowed; | |
109 | ||
110 | vm_acct_memory(pages); | |
111 | ||
112 | /* | |
113 | * Sometimes we want to use more memory than we have | |
114 | */ | |
115 | if (sysctl_overcommit_memory == OVERCOMMIT_ALWAYS) | |
116 | return 0; | |
117 | ||
118 | if (sysctl_overcommit_memory == OVERCOMMIT_GUESS) { | |
119 | unsigned long n; | |
120 | ||
347ce434 | 121 | free = global_page_state(NR_FILE_PAGES); |
1da177e4 LT |
122 | free += nr_swap_pages; |
123 | ||
124 | /* | |
125 | * Any slabs which are created with the | |
126 | * SLAB_RECLAIM_ACCOUNT flag claim to have contents | |
127 | * which are reclaimable, under pressure. The dentry | |
128 | * cache and most inode caches should fall into this | |
129 | */ | |
972d1a7b | 130 | free += global_page_state(NR_SLAB_RECLAIMABLE); |
1da177e4 LT |
131 | |
132 | /* | |
133 | * Leave the last 3% for root | |
134 | */ | |
135 | if (!cap_sys_admin) | |
136 | free -= free / 32; | |
137 | ||
138 | if (free > pages) | |
139 | return 0; | |
140 | ||
141 | /* | |
142 | * nr_free_pages() is very expensive on large systems, | |
143 | * only call if we're about to fail. | |
144 | */ | |
145 | n = nr_free_pages(); | |
6d9f7839 HA |
146 | |
147 | /* | |
148 | * Leave reserved pages. The pages are not for anonymous pages. | |
149 | */ | |
150 | if (n <= totalreserve_pages) | |
151 | goto error; | |
152 | else | |
153 | n -= totalreserve_pages; | |
154 | ||
155 | /* | |
156 | * Leave the last 3% for root | |
157 | */ | |
1da177e4 LT |
158 | if (!cap_sys_admin) |
159 | n -= n / 32; | |
160 | free += n; | |
161 | ||
162 | if (free > pages) | |
163 | return 0; | |
6d9f7839 HA |
164 | |
165 | goto error; | |
1da177e4 LT |
166 | } |
167 | ||
168 | allowed = (totalram_pages - hugetlb_total_pages()) | |
169 | * sysctl_overcommit_ratio / 100; | |
170 | /* | |
171 | * Leave the last 3% for root | |
172 | */ | |
173 | if (!cap_sys_admin) | |
174 | allowed -= allowed / 32; | |
175 | allowed += total_swap_pages; | |
176 | ||
177 | /* Don't let a single process grow too big: | |
178 | leave 3% of the size of this process for other processes */ | |
731572d3 AC |
179 | if (mm) |
180 | allowed -= mm->total_vm / 32; | |
1da177e4 | 181 | |
00a62ce9 | 182 | if (percpu_counter_read_positive(&vm_committed_as) < allowed) |
1da177e4 | 183 | return 0; |
6d9f7839 | 184 | error: |
1da177e4 LT |
185 | vm_unacct_memory(pages); |
186 | ||
187 | return -ENOMEM; | |
188 | } | |
189 | ||
1da177e4 LT |
190 | /* |
191 | * Requires inode->i_mapping->i_mmap_lock | |
192 | */ | |
193 | static void __remove_shared_vm_struct(struct vm_area_struct *vma, | |
194 | struct file *file, struct address_space *mapping) | |
195 | { | |
196 | if (vma->vm_flags & VM_DENYWRITE) | |
d3ac7f89 | 197 | atomic_inc(&file->f_path.dentry->d_inode->i_writecount); |
1da177e4 LT |
198 | if (vma->vm_flags & VM_SHARED) |
199 | mapping->i_mmap_writable--; | |
200 | ||
201 | flush_dcache_mmap_lock(mapping); | |
202 | if (unlikely(vma->vm_flags & VM_NONLINEAR)) | |
203 | list_del_init(&vma->shared.vm_set.list); | |
204 | else | |
205 | vma_prio_tree_remove(vma, &mapping->i_mmap); | |
206 | flush_dcache_mmap_unlock(mapping); | |
207 | } | |
208 | ||
209 | /* | |
a8fb5618 HD |
210 | * Unlink a file-based vm structure from its prio_tree, to hide |
211 | * vma from rmap and vmtruncate before freeing its page tables. | |
1da177e4 | 212 | */ |
a8fb5618 | 213 | void unlink_file_vma(struct vm_area_struct *vma) |
1da177e4 LT |
214 | { |
215 | struct file *file = vma->vm_file; | |
216 | ||
1da177e4 LT |
217 | if (file) { |
218 | struct address_space *mapping = file->f_mapping; | |
219 | spin_lock(&mapping->i_mmap_lock); | |
220 | __remove_shared_vm_struct(vma, file, mapping); | |
221 | spin_unlock(&mapping->i_mmap_lock); | |
222 | } | |
a8fb5618 HD |
223 | } |
224 | ||
225 | /* | |
226 | * Close a vm structure and free it, returning the next. | |
227 | */ | |
228 | static struct vm_area_struct *remove_vma(struct vm_area_struct *vma) | |
229 | { | |
230 | struct vm_area_struct *next = vma->vm_next; | |
231 | ||
a8fb5618 | 232 | might_sleep(); |
1da177e4 LT |
233 | if (vma->vm_ops && vma->vm_ops->close) |
234 | vma->vm_ops->close(vma); | |
925d1c40 | 235 | if (vma->vm_file) { |
a8fb5618 | 236 | fput(vma->vm_file); |
925d1c40 MH |
237 | if (vma->vm_flags & VM_EXECUTABLE) |
238 | removed_exe_file_vma(vma->vm_mm); | |
239 | } | |
f0be3d32 | 240 | mpol_put(vma_policy(vma)); |
1da177e4 | 241 | kmem_cache_free(vm_area_cachep, vma); |
a8fb5618 | 242 | return next; |
1da177e4 LT |
243 | } |
244 | ||
6a6160a7 | 245 | SYSCALL_DEFINE1(brk, unsigned long, brk) |
1da177e4 LT |
246 | { |
247 | unsigned long rlim, retval; | |
248 | unsigned long newbrk, oldbrk; | |
249 | struct mm_struct *mm = current->mm; | |
a5b4592c | 250 | unsigned long min_brk; |
1da177e4 LT |
251 | |
252 | down_write(&mm->mmap_sem); | |
253 | ||
a5b4592c JK |
254 | #ifdef CONFIG_COMPAT_BRK |
255 | min_brk = mm->end_code; | |
256 | #else | |
257 | min_brk = mm->start_brk; | |
258 | #endif | |
259 | if (brk < min_brk) | |
1da177e4 | 260 | goto out; |
1e624196 RG |
261 | |
262 | /* | |
263 | * Check against rlimit here. If this check is done later after the test | |
264 | * of oldbrk with newbrk then it can escape the test and let the data | |
265 | * segment grow beyond its set limit the in case where the limit is | |
266 | * not page aligned -Ram Gupta | |
267 | */ | |
59e99e5b | 268 | rlim = rlimit(RLIMIT_DATA); |
c1d171a0 JK |
269 | if (rlim < RLIM_INFINITY && (brk - mm->start_brk) + |
270 | (mm->end_data - mm->start_data) > rlim) | |
1e624196 RG |
271 | goto out; |
272 | ||
1da177e4 LT |
273 | newbrk = PAGE_ALIGN(brk); |
274 | oldbrk = PAGE_ALIGN(mm->brk); | |
275 | if (oldbrk == newbrk) | |
276 | goto set_brk; | |
277 | ||
278 | /* Always allow shrinking brk. */ | |
279 | if (brk <= mm->brk) { | |
280 | if (!do_munmap(mm, newbrk, oldbrk-newbrk)) | |
281 | goto set_brk; | |
282 | goto out; | |
283 | } | |
284 | ||
1da177e4 LT |
285 | /* Check against existing mmap mappings. */ |
286 | if (find_vma_intersection(mm, oldbrk, newbrk+PAGE_SIZE)) | |
287 | goto out; | |
288 | ||
289 | /* Ok, looks good - let it rip. */ | |
290 | if (do_brk(oldbrk, newbrk-oldbrk) != oldbrk) | |
291 | goto out; | |
292 | set_brk: | |
293 | mm->brk = brk; | |
294 | out: | |
295 | retval = mm->brk; | |
296 | up_write(&mm->mmap_sem); | |
297 | return retval; | |
298 | } | |
299 | ||
300 | #ifdef DEBUG_MM_RB | |
301 | static int browse_rb(struct rb_root *root) | |
302 | { | |
303 | int i = 0, j; | |
304 | struct rb_node *nd, *pn = NULL; | |
305 | unsigned long prev = 0, pend = 0; | |
306 | ||
307 | for (nd = rb_first(root); nd; nd = rb_next(nd)) { | |
308 | struct vm_area_struct *vma; | |
309 | vma = rb_entry(nd, struct vm_area_struct, vm_rb); | |
310 | if (vma->vm_start < prev) | |
311 | printk("vm_start %lx prev %lx\n", vma->vm_start, prev), i = -1; | |
312 | if (vma->vm_start < pend) | |
313 | printk("vm_start %lx pend %lx\n", vma->vm_start, pend); | |
314 | if (vma->vm_start > vma->vm_end) | |
315 | printk("vm_end %lx < vm_start %lx\n", vma->vm_end, vma->vm_start); | |
316 | i++; | |
317 | pn = nd; | |
d1af65d1 DM |
318 | prev = vma->vm_start; |
319 | pend = vma->vm_end; | |
1da177e4 LT |
320 | } |
321 | j = 0; | |
322 | for (nd = pn; nd; nd = rb_prev(nd)) { | |
323 | j++; | |
324 | } | |
325 | if (i != j) | |
326 | printk("backwards %d, forwards %d\n", j, i), i = 0; | |
327 | return i; | |
328 | } | |
329 | ||
330 | void validate_mm(struct mm_struct *mm) | |
331 | { | |
332 | int bug = 0; | |
333 | int i = 0; | |
334 | struct vm_area_struct *tmp = mm->mmap; | |
335 | while (tmp) { | |
336 | tmp = tmp->vm_next; | |
337 | i++; | |
338 | } | |
339 | if (i != mm->map_count) | |
340 | printk("map_count %d vm_next %d\n", mm->map_count, i), bug = 1; | |
341 | i = browse_rb(&mm->mm_rb); | |
342 | if (i != mm->map_count) | |
343 | printk("map_count %d rb %d\n", mm->map_count, i), bug = 1; | |
46a350ef | 344 | BUG_ON(bug); |
1da177e4 LT |
345 | } |
346 | #else | |
347 | #define validate_mm(mm) do { } while (0) | |
348 | #endif | |
349 | ||
350 | static struct vm_area_struct * | |
351 | find_vma_prepare(struct mm_struct *mm, unsigned long addr, | |
352 | struct vm_area_struct **pprev, struct rb_node ***rb_link, | |
353 | struct rb_node ** rb_parent) | |
354 | { | |
355 | struct vm_area_struct * vma; | |
356 | struct rb_node ** __rb_link, * __rb_parent, * rb_prev; | |
357 | ||
358 | __rb_link = &mm->mm_rb.rb_node; | |
359 | rb_prev = __rb_parent = NULL; | |
360 | vma = NULL; | |
361 | ||
362 | while (*__rb_link) { | |
363 | struct vm_area_struct *vma_tmp; | |
364 | ||
365 | __rb_parent = *__rb_link; | |
366 | vma_tmp = rb_entry(__rb_parent, struct vm_area_struct, vm_rb); | |
367 | ||
368 | if (vma_tmp->vm_end > addr) { | |
369 | vma = vma_tmp; | |
370 | if (vma_tmp->vm_start <= addr) | |
dfe195fb | 371 | break; |
1da177e4 LT |
372 | __rb_link = &__rb_parent->rb_left; |
373 | } else { | |
374 | rb_prev = __rb_parent; | |
375 | __rb_link = &__rb_parent->rb_right; | |
376 | } | |
377 | } | |
378 | ||
379 | *pprev = NULL; | |
380 | if (rb_prev) | |
381 | *pprev = rb_entry(rb_prev, struct vm_area_struct, vm_rb); | |
382 | *rb_link = __rb_link; | |
383 | *rb_parent = __rb_parent; | |
384 | return vma; | |
385 | } | |
386 | ||
387 | static inline void | |
388 | __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma, | |
389 | struct vm_area_struct *prev, struct rb_node *rb_parent) | |
390 | { | |
391 | if (prev) { | |
392 | vma->vm_next = prev->vm_next; | |
393 | prev->vm_next = vma; | |
394 | } else { | |
395 | mm->mmap = vma; | |
396 | if (rb_parent) | |
397 | vma->vm_next = rb_entry(rb_parent, | |
398 | struct vm_area_struct, vm_rb); | |
399 | else | |
400 | vma->vm_next = NULL; | |
401 | } | |
402 | } | |
403 | ||
404 | void __vma_link_rb(struct mm_struct *mm, struct vm_area_struct *vma, | |
405 | struct rb_node **rb_link, struct rb_node *rb_parent) | |
406 | { | |
407 | rb_link_node(&vma->vm_rb, rb_parent, rb_link); | |
408 | rb_insert_color(&vma->vm_rb, &mm->mm_rb); | |
409 | } | |
410 | ||
cb8f488c | 411 | static void __vma_link_file(struct vm_area_struct *vma) |
1da177e4 | 412 | { |
48aae425 | 413 | struct file *file; |
1da177e4 LT |
414 | |
415 | file = vma->vm_file; | |
416 | if (file) { | |
417 | struct address_space *mapping = file->f_mapping; | |
418 | ||
419 | if (vma->vm_flags & VM_DENYWRITE) | |
d3ac7f89 | 420 | atomic_dec(&file->f_path.dentry->d_inode->i_writecount); |
1da177e4 LT |
421 | if (vma->vm_flags & VM_SHARED) |
422 | mapping->i_mmap_writable++; | |
423 | ||
424 | flush_dcache_mmap_lock(mapping); | |
425 | if (unlikely(vma->vm_flags & VM_NONLINEAR)) | |
426 | vma_nonlinear_insert(vma, &mapping->i_mmap_nonlinear); | |
427 | else | |
428 | vma_prio_tree_insert(vma, &mapping->i_mmap); | |
429 | flush_dcache_mmap_unlock(mapping); | |
430 | } | |
431 | } | |
432 | ||
433 | static void | |
434 | __vma_link(struct mm_struct *mm, struct vm_area_struct *vma, | |
435 | struct vm_area_struct *prev, struct rb_node **rb_link, | |
436 | struct rb_node *rb_parent) | |
437 | { | |
438 | __vma_link_list(mm, vma, prev, rb_parent); | |
439 | __vma_link_rb(mm, vma, rb_link, rb_parent); | |
1da177e4 LT |
440 | } |
441 | ||
442 | static void vma_link(struct mm_struct *mm, struct vm_area_struct *vma, | |
443 | struct vm_area_struct *prev, struct rb_node **rb_link, | |
444 | struct rb_node *rb_parent) | |
445 | { | |
446 | struct address_space *mapping = NULL; | |
447 | ||
448 | if (vma->vm_file) | |
449 | mapping = vma->vm_file->f_mapping; | |
450 | ||
451 | if (mapping) { | |
452 | spin_lock(&mapping->i_mmap_lock); | |
453 | vma->vm_truncate_count = mapping->truncate_count; | |
454 | } | |
455 | anon_vma_lock(vma); | |
456 | ||
457 | __vma_link(mm, vma, prev, rb_link, rb_parent); | |
458 | __vma_link_file(vma); | |
459 | ||
460 | anon_vma_unlock(vma); | |
461 | if (mapping) | |
462 | spin_unlock(&mapping->i_mmap_lock); | |
463 | ||
464 | mm->map_count++; | |
465 | validate_mm(mm); | |
466 | } | |
467 | ||
468 | /* | |
469 | * Helper for vma_adjust in the split_vma insert case: | |
470 | * insert vm structure into list and rbtree and anon_vma, | |
471 | * but it has already been inserted into prio_tree earlier. | |
472 | */ | |
48aae425 | 473 | static void __insert_vm_struct(struct mm_struct *mm, struct vm_area_struct *vma) |
1da177e4 | 474 | { |
48aae425 Z |
475 | struct vm_area_struct *__vma, *prev; |
476 | struct rb_node **rb_link, *rb_parent; | |
1da177e4 LT |
477 | |
478 | __vma = find_vma_prepare(mm, vma->vm_start,&prev, &rb_link, &rb_parent); | |
46a350ef | 479 | BUG_ON(__vma && __vma->vm_start < vma->vm_end); |
1da177e4 LT |
480 | __vma_link(mm, vma, prev, rb_link, rb_parent); |
481 | mm->map_count++; | |
482 | } | |
483 | ||
484 | static inline void | |
485 | __vma_unlink(struct mm_struct *mm, struct vm_area_struct *vma, | |
486 | struct vm_area_struct *prev) | |
487 | { | |
488 | prev->vm_next = vma->vm_next; | |
489 | rb_erase(&vma->vm_rb, &mm->mm_rb); | |
490 | if (mm->mmap_cache == vma) | |
491 | mm->mmap_cache = prev; | |
492 | } | |
493 | ||
494 | /* | |
495 | * We cannot adjust vm_start, vm_end, vm_pgoff fields of a vma that | |
496 | * is already present in an i_mmap tree without adjusting the tree. | |
497 | * The following helper function should be used when such adjustments | |
498 | * are necessary. The "insert" vma (if any) is to be inserted | |
499 | * before we drop the necessary locks. | |
500 | */ | |
5beb4930 | 501 | int vma_adjust(struct vm_area_struct *vma, unsigned long start, |
1da177e4 LT |
502 | unsigned long end, pgoff_t pgoff, struct vm_area_struct *insert) |
503 | { | |
504 | struct mm_struct *mm = vma->vm_mm; | |
505 | struct vm_area_struct *next = vma->vm_next; | |
506 | struct vm_area_struct *importer = NULL; | |
507 | struct address_space *mapping = NULL; | |
508 | struct prio_tree_root *root = NULL; | |
509 | struct file *file = vma->vm_file; | |
510 | struct anon_vma *anon_vma = NULL; | |
511 | long adjust_next = 0; | |
512 | int remove_next = 0; | |
513 | ||
514 | if (next && !insert) { | |
515 | if (end >= next->vm_end) { | |
516 | /* | |
517 | * vma expands, overlapping all the next, and | |
518 | * perhaps the one after too (mprotect case 6). | |
519 | */ | |
520 | again: remove_next = 1 + (end > next->vm_end); | |
521 | end = next->vm_end; | |
522 | anon_vma = next->anon_vma; | |
523 | importer = vma; | |
524 | } else if (end > next->vm_start) { | |
525 | /* | |
526 | * vma expands, overlapping part of the next: | |
527 | * mprotect case 5 shifting the boundary up. | |
528 | */ | |
529 | adjust_next = (end - next->vm_start) >> PAGE_SHIFT; | |
530 | anon_vma = next->anon_vma; | |
531 | importer = vma; | |
532 | } else if (end < vma->vm_end) { | |
533 | /* | |
534 | * vma shrinks, and !insert tells it's not | |
535 | * split_vma inserting another: so it must be | |
536 | * mprotect case 4 shifting the boundary down. | |
537 | */ | |
538 | adjust_next = - ((vma->vm_end - end) >> PAGE_SHIFT); | |
539 | anon_vma = next->anon_vma; | |
540 | importer = next; | |
541 | } | |
542 | } | |
543 | ||
5beb4930 RR |
544 | /* |
545 | * When changing only vma->vm_end, we don't really need anon_vma lock. | |
546 | */ | |
547 | if (vma->anon_vma && (insert || importer || start != vma->vm_start)) | |
548 | anon_vma = vma->anon_vma; | |
549 | if (anon_vma) { | |
550 | /* | |
551 | * Easily overlooked: when mprotect shifts the boundary, | |
552 | * make sure the expanding vma has anon_vma set if the | |
553 | * shrinking vma had, to cover any anon pages imported. | |
554 | */ | |
555 | if (importer && !importer->anon_vma) { | |
556 | /* Block reverse map lookups until things are set up. */ | |
5beb4930 | 557 | if (anon_vma_clone(importer, vma)) { |
5beb4930 RR |
558 | return -ENOMEM; |
559 | } | |
560 | importer->anon_vma = anon_vma; | |
561 | } | |
562 | } | |
563 | ||
1da177e4 LT |
564 | if (file) { |
565 | mapping = file->f_mapping; | |
566 | if (!(vma->vm_flags & VM_NONLINEAR)) | |
567 | root = &mapping->i_mmap; | |
568 | spin_lock(&mapping->i_mmap_lock); | |
569 | if (importer && | |
570 | vma->vm_truncate_count != next->vm_truncate_count) { | |
571 | /* | |
572 | * unmap_mapping_range might be in progress: | |
573 | * ensure that the expanding vma is rescanned. | |
574 | */ | |
575 | importer->vm_truncate_count = 0; | |
576 | } | |
577 | if (insert) { | |
578 | insert->vm_truncate_count = vma->vm_truncate_count; | |
579 | /* | |
580 | * Put into prio_tree now, so instantiated pages | |
581 | * are visible to arm/parisc __flush_dcache_page | |
582 | * throughout; but we cannot insert into address | |
583 | * space until vma start or end is updated. | |
584 | */ | |
585 | __vma_link_file(insert); | |
586 | } | |
587 | } | |
588 | ||
1da177e4 LT |
589 | if (root) { |
590 | flush_dcache_mmap_lock(mapping); | |
591 | vma_prio_tree_remove(vma, root); | |
592 | if (adjust_next) | |
593 | vma_prio_tree_remove(next, root); | |
594 | } | |
595 | ||
596 | vma->vm_start = start; | |
597 | vma->vm_end = end; | |
598 | vma->vm_pgoff = pgoff; | |
599 | if (adjust_next) { | |
600 | next->vm_start += adjust_next << PAGE_SHIFT; | |
601 | next->vm_pgoff += adjust_next; | |
602 | } | |
603 | ||
604 | if (root) { | |
605 | if (adjust_next) | |
606 | vma_prio_tree_insert(next, root); | |
607 | vma_prio_tree_insert(vma, root); | |
608 | flush_dcache_mmap_unlock(mapping); | |
609 | } | |
610 | ||
611 | if (remove_next) { | |
612 | /* | |
613 | * vma_merge has merged next into vma, and needs | |
614 | * us to remove next before dropping the locks. | |
615 | */ | |
616 | __vma_unlink(mm, next, vma); | |
617 | if (file) | |
618 | __remove_shared_vm_struct(next, file, mapping); | |
1da177e4 LT |
619 | } else if (insert) { |
620 | /* | |
621 | * split_vma has split insert from vma, and needs | |
622 | * us to insert it before dropping the locks | |
623 | * (it may either follow vma or precede it). | |
624 | */ | |
625 | __insert_vm_struct(mm, insert); | |
626 | } | |
627 | ||
1da177e4 LT |
628 | if (mapping) |
629 | spin_unlock(&mapping->i_mmap_lock); | |
630 | ||
631 | if (remove_next) { | |
925d1c40 | 632 | if (file) { |
1da177e4 | 633 | fput(file); |
925d1c40 MH |
634 | if (next->vm_flags & VM_EXECUTABLE) |
635 | removed_exe_file_vma(mm); | |
636 | } | |
5beb4930 RR |
637 | if (next->anon_vma) |
638 | anon_vma_merge(vma, next); | |
1da177e4 | 639 | mm->map_count--; |
f0be3d32 | 640 | mpol_put(vma_policy(next)); |
1da177e4 LT |
641 | kmem_cache_free(vm_area_cachep, next); |
642 | /* | |
643 | * In mprotect's case 6 (see comments on vma_merge), | |
644 | * we must remove another next too. It would clutter | |
645 | * up the code too much to do both in one go. | |
646 | */ | |
647 | if (remove_next == 2) { | |
648 | next = vma->vm_next; | |
649 | goto again; | |
650 | } | |
651 | } | |
652 | ||
653 | validate_mm(mm); | |
5beb4930 RR |
654 | |
655 | return 0; | |
1da177e4 LT |
656 | } |
657 | ||
658 | /* | |
659 | * If the vma has a ->close operation then the driver probably needs to release | |
660 | * per-vma resources, so we don't attempt to merge those. | |
661 | */ | |
1da177e4 LT |
662 | static inline int is_mergeable_vma(struct vm_area_struct *vma, |
663 | struct file *file, unsigned long vm_flags) | |
664 | { | |
8314c4f2 HD |
665 | /* VM_CAN_NONLINEAR may get set later by f_op->mmap() */ |
666 | if ((vma->vm_flags ^ vm_flags) & ~VM_CAN_NONLINEAR) | |
1da177e4 LT |
667 | return 0; |
668 | if (vma->vm_file != file) | |
669 | return 0; | |
670 | if (vma->vm_ops && vma->vm_ops->close) | |
671 | return 0; | |
672 | return 1; | |
673 | } | |
674 | ||
675 | static inline int is_mergeable_anon_vma(struct anon_vma *anon_vma1, | |
676 | struct anon_vma *anon_vma2) | |
677 | { | |
678 | return !anon_vma1 || !anon_vma2 || (anon_vma1 == anon_vma2); | |
679 | } | |
680 | ||
681 | /* | |
682 | * Return true if we can merge this (vm_flags,anon_vma,file,vm_pgoff) | |
683 | * in front of (at a lower virtual address and file offset than) the vma. | |
684 | * | |
685 | * We cannot merge two vmas if they have differently assigned (non-NULL) | |
686 | * anon_vmas, nor if same anon_vma is assigned but offsets incompatible. | |
687 | * | |
688 | * We don't check here for the merged mmap wrapping around the end of pagecache | |
689 | * indices (16TB on ia32) because do_mmap_pgoff() does not permit mmap's which | |
690 | * wrap, nor mmaps which cover the final page at index -1UL. | |
691 | */ | |
692 | static int | |
693 | can_vma_merge_before(struct vm_area_struct *vma, unsigned long vm_flags, | |
694 | struct anon_vma *anon_vma, struct file *file, pgoff_t vm_pgoff) | |
695 | { | |
696 | if (is_mergeable_vma(vma, file, vm_flags) && | |
697 | is_mergeable_anon_vma(anon_vma, vma->anon_vma)) { | |
698 | if (vma->vm_pgoff == vm_pgoff) | |
699 | return 1; | |
700 | } | |
701 | return 0; | |
702 | } | |
703 | ||
704 | /* | |
705 | * Return true if we can merge this (vm_flags,anon_vma,file,vm_pgoff) | |
706 | * beyond (at a higher virtual address and file offset than) the vma. | |
707 | * | |
708 | * We cannot merge two vmas if they have differently assigned (non-NULL) | |
709 | * anon_vmas, nor if same anon_vma is assigned but offsets incompatible. | |
710 | */ | |
711 | static int | |
712 | can_vma_merge_after(struct vm_area_struct *vma, unsigned long vm_flags, | |
713 | struct anon_vma *anon_vma, struct file *file, pgoff_t vm_pgoff) | |
714 | { | |
715 | if (is_mergeable_vma(vma, file, vm_flags) && | |
716 | is_mergeable_anon_vma(anon_vma, vma->anon_vma)) { | |
717 | pgoff_t vm_pglen; | |
718 | vm_pglen = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; | |
719 | if (vma->vm_pgoff + vm_pglen == vm_pgoff) | |
720 | return 1; | |
721 | } | |
722 | return 0; | |
723 | } | |
724 | ||
725 | /* | |
726 | * Given a mapping request (addr,end,vm_flags,file,pgoff), figure out | |
727 | * whether that can be merged with its predecessor or its successor. | |
728 | * Or both (it neatly fills a hole). | |
729 | * | |
730 | * In most cases - when called for mmap, brk or mremap - [addr,end) is | |
731 | * certain not to be mapped by the time vma_merge is called; but when | |
732 | * called for mprotect, it is certain to be already mapped (either at | |
733 | * an offset within prev, or at the start of next), and the flags of | |
734 | * this area are about to be changed to vm_flags - and the no-change | |
735 | * case has already been eliminated. | |
736 | * | |
737 | * The following mprotect cases have to be considered, where AAAA is | |
738 | * the area passed down from mprotect_fixup, never extending beyond one | |
739 | * vma, PPPPPP is the prev vma specified, and NNNNNN the next vma after: | |
740 | * | |
741 | * AAAA AAAA AAAA AAAA | |
742 | * PPPPPPNNNNNN PPPPPPNNNNNN PPPPPPNNNNNN PPPPNNNNXXXX | |
743 | * cannot merge might become might become might become | |
744 | * PPNNNNNNNNNN PPPPPPPPPPNN PPPPPPPPPPPP 6 or | |
745 | * mmap, brk or case 4 below case 5 below PPPPPPPPXXXX 7 or | |
746 | * mremap move: PPPPNNNNNNNN 8 | |
747 | * AAAA | |
748 | * PPPP NNNN PPPPPPPPPPPP PPPPPPPPNNNN PPPPNNNNNNNN | |
749 | * might become case 1 below case 2 below case 3 below | |
750 | * | |
751 | * Odd one out? Case 8, because it extends NNNN but needs flags of XXXX: | |
752 | * mprotect_fixup updates vm_flags & vm_page_prot on successful return. | |
753 | */ | |
754 | struct vm_area_struct *vma_merge(struct mm_struct *mm, | |
755 | struct vm_area_struct *prev, unsigned long addr, | |
756 | unsigned long end, unsigned long vm_flags, | |
757 | struct anon_vma *anon_vma, struct file *file, | |
758 | pgoff_t pgoff, struct mempolicy *policy) | |
759 | { | |
760 | pgoff_t pglen = (end - addr) >> PAGE_SHIFT; | |
761 | struct vm_area_struct *area, *next; | |
5beb4930 | 762 | int err; |
1da177e4 LT |
763 | |
764 | /* | |
765 | * We later require that vma->vm_flags == vm_flags, | |
766 | * so this tests vma->vm_flags & VM_SPECIAL, too. | |
767 | */ | |
768 | if (vm_flags & VM_SPECIAL) | |
769 | return NULL; | |
770 | ||
771 | if (prev) | |
772 | next = prev->vm_next; | |
773 | else | |
774 | next = mm->mmap; | |
775 | area = next; | |
776 | if (next && next->vm_end == end) /* cases 6, 7, 8 */ | |
777 | next = next->vm_next; | |
778 | ||
779 | /* | |
780 | * Can it merge with the predecessor? | |
781 | */ | |
782 | if (prev && prev->vm_end == addr && | |
783 | mpol_equal(vma_policy(prev), policy) && | |
784 | can_vma_merge_after(prev, vm_flags, | |
785 | anon_vma, file, pgoff)) { | |
786 | /* | |
787 | * OK, it can. Can we now merge in the successor as well? | |
788 | */ | |
789 | if (next && end == next->vm_start && | |
790 | mpol_equal(policy, vma_policy(next)) && | |
791 | can_vma_merge_before(next, vm_flags, | |
792 | anon_vma, file, pgoff+pglen) && | |
793 | is_mergeable_anon_vma(prev->anon_vma, | |
794 | next->anon_vma)) { | |
795 | /* cases 1, 6 */ | |
5beb4930 | 796 | err = vma_adjust(prev, prev->vm_start, |
1da177e4 LT |
797 | next->vm_end, prev->vm_pgoff, NULL); |
798 | } else /* cases 2, 5, 7 */ | |
5beb4930 | 799 | err = vma_adjust(prev, prev->vm_start, |
1da177e4 | 800 | end, prev->vm_pgoff, NULL); |
5beb4930 RR |
801 | if (err) |
802 | return NULL; | |
1da177e4 LT |
803 | return prev; |
804 | } | |
805 | ||
806 | /* | |
807 | * Can this new request be merged in front of next? | |
808 | */ | |
809 | if (next && end == next->vm_start && | |
810 | mpol_equal(policy, vma_policy(next)) && | |
811 | can_vma_merge_before(next, vm_flags, | |
812 | anon_vma, file, pgoff+pglen)) { | |
813 | if (prev && addr < prev->vm_end) /* case 4 */ | |
5beb4930 | 814 | err = vma_adjust(prev, prev->vm_start, |
1da177e4 LT |
815 | addr, prev->vm_pgoff, NULL); |
816 | else /* cases 3, 8 */ | |
5beb4930 | 817 | err = vma_adjust(area, addr, next->vm_end, |
1da177e4 | 818 | next->vm_pgoff - pglen, NULL); |
5beb4930 RR |
819 | if (err) |
820 | return NULL; | |
1da177e4 LT |
821 | return area; |
822 | } | |
823 | ||
824 | return NULL; | |
825 | } | |
826 | ||
827 | /* | |
828 | * find_mergeable_anon_vma is used by anon_vma_prepare, to check | |
829 | * neighbouring vmas for a suitable anon_vma, before it goes off | |
830 | * to allocate a new anon_vma. It checks because a repetitive | |
831 | * sequence of mprotects and faults may otherwise lead to distinct | |
832 | * anon_vmas being allocated, preventing vma merge in subsequent | |
833 | * mprotect. | |
834 | */ | |
835 | struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *vma) | |
836 | { | |
837 | struct vm_area_struct *near; | |
838 | unsigned long vm_flags; | |
839 | ||
840 | near = vma->vm_next; | |
841 | if (!near) | |
842 | goto try_prev; | |
843 | ||
844 | /* | |
845 | * Since only mprotect tries to remerge vmas, match flags | |
846 | * which might be mprotected into each other later on. | |
847 | * Neither mlock nor madvise tries to remerge at present, | |
848 | * so leave their flags as obstructing a merge. | |
849 | */ | |
850 | vm_flags = vma->vm_flags & ~(VM_READ|VM_WRITE|VM_EXEC); | |
851 | vm_flags |= near->vm_flags & (VM_READ|VM_WRITE|VM_EXEC); | |
852 | ||
853 | if (near->anon_vma && vma->vm_end == near->vm_start && | |
854 | mpol_equal(vma_policy(vma), vma_policy(near)) && | |
855 | can_vma_merge_before(near, vm_flags, | |
856 | NULL, vma->vm_file, vma->vm_pgoff + | |
857 | ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT))) | |
858 | return near->anon_vma; | |
859 | try_prev: | |
860 | /* | |
861 | * It is potentially slow to have to call find_vma_prev here. | |
862 | * But it's only on the first write fault on the vma, not | |
863 | * every time, and we could devise a way to avoid it later | |
864 | * (e.g. stash info in next's anon_vma_node when assigning | |
865 | * an anon_vma, or when trying vma_merge). Another time. | |
866 | */ | |
46a350ef | 867 | BUG_ON(find_vma_prev(vma->vm_mm, vma->vm_start, &near) != vma); |
1da177e4 LT |
868 | if (!near) |
869 | goto none; | |
870 | ||
871 | vm_flags = vma->vm_flags & ~(VM_READ|VM_WRITE|VM_EXEC); | |
872 | vm_flags |= near->vm_flags & (VM_READ|VM_WRITE|VM_EXEC); | |
873 | ||
874 | if (near->anon_vma && near->vm_end == vma->vm_start && | |
875 | mpol_equal(vma_policy(near), vma_policy(vma)) && | |
876 | can_vma_merge_after(near, vm_flags, | |
877 | NULL, vma->vm_file, vma->vm_pgoff)) | |
878 | return near->anon_vma; | |
879 | none: | |
880 | /* | |
881 | * There's no absolute need to look only at touching neighbours: | |
882 | * we could search further afield for "compatible" anon_vmas. | |
883 | * But it would probably just be a waste of time searching, | |
884 | * or lead to too many vmas hanging off the same anon_vma. | |
885 | * We're trying to allow mprotect remerging later on, | |
886 | * not trying to minimize memory used for anon_vmas. | |
887 | */ | |
888 | return NULL; | |
889 | } | |
890 | ||
891 | #ifdef CONFIG_PROC_FS | |
ab50b8ed | 892 | void vm_stat_account(struct mm_struct *mm, unsigned long flags, |
1da177e4 LT |
893 | struct file *file, long pages) |
894 | { | |
895 | const unsigned long stack_flags | |
896 | = VM_STACK_FLAGS & (VM_GROWSUP|VM_GROWSDOWN); | |
897 | ||
1da177e4 LT |
898 | if (file) { |
899 | mm->shared_vm += pages; | |
900 | if ((flags & (VM_EXEC|VM_WRITE)) == VM_EXEC) | |
901 | mm->exec_vm += pages; | |
902 | } else if (flags & stack_flags) | |
903 | mm->stack_vm += pages; | |
904 | if (flags & (VM_RESERVED|VM_IO)) | |
905 | mm->reserved_vm += pages; | |
906 | } | |
907 | #endif /* CONFIG_PROC_FS */ | |
908 | ||
909 | /* | |
27f5de79 | 910 | * The caller must hold down_write(¤t->mm->mmap_sem). |
1da177e4 LT |
911 | */ |
912 | ||
48aae425 | 913 | unsigned long do_mmap_pgoff(struct file *file, unsigned long addr, |
1da177e4 LT |
914 | unsigned long len, unsigned long prot, |
915 | unsigned long flags, unsigned long pgoff) | |
916 | { | |
917 | struct mm_struct * mm = current->mm; | |
1da177e4 LT |
918 | struct inode *inode; |
919 | unsigned int vm_flags; | |
1da177e4 | 920 | int error; |
0165ab44 | 921 | unsigned long reqprot = prot; |
1da177e4 | 922 | |
1da177e4 LT |
923 | /* |
924 | * Does the application expect PROT_READ to imply PROT_EXEC? | |
925 | * | |
926 | * (the exception is when the underlying filesystem is noexec | |
927 | * mounted, in which case we dont add PROT_EXEC.) | |
928 | */ | |
929 | if ((prot & PROT_READ) && (current->personality & READ_IMPLIES_EXEC)) | |
d3ac7f89 | 930 | if (!(file && (file->f_path.mnt->mnt_flags & MNT_NOEXEC))) |
1da177e4 LT |
931 | prot |= PROT_EXEC; |
932 | ||
933 | if (!len) | |
934 | return -EINVAL; | |
935 | ||
7cd94146 EP |
936 | if (!(flags & MAP_FIXED)) |
937 | addr = round_hint_to_min(addr); | |
938 | ||
1da177e4 LT |
939 | /* Careful about overflows.. */ |
940 | len = PAGE_ALIGN(len); | |
9206de95 | 941 | if (!len) |
1da177e4 LT |
942 | return -ENOMEM; |
943 | ||
944 | /* offset overflow? */ | |
945 | if ((pgoff + (len >> PAGE_SHIFT)) < pgoff) | |
946 | return -EOVERFLOW; | |
947 | ||
948 | /* Too many mappings? */ | |
949 | if (mm->map_count > sysctl_max_map_count) | |
950 | return -ENOMEM; | |
951 | ||
952 | /* Obtain the address to map to. we verify (or select) it and ensure | |
953 | * that it represents a valid section of the address space. | |
954 | */ | |
955 | addr = get_unmapped_area(file, addr, len, pgoff, flags); | |
956 | if (addr & ~PAGE_MASK) | |
957 | return addr; | |
958 | ||
959 | /* Do simple checking here so the lower-level routines won't have | |
960 | * to. we assume access permissions have been handled by the open | |
961 | * of the memory object, so we don't do any here. | |
962 | */ | |
963 | vm_flags = calc_vm_prot_bits(prot) | calc_vm_flag_bits(flags) | | |
964 | mm->def_flags | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC; | |
965 | ||
cdf7b341 | 966 | if (flags & MAP_LOCKED) |
1da177e4 LT |
967 | if (!can_do_mlock()) |
968 | return -EPERM; | |
ba470de4 | 969 | |
1da177e4 LT |
970 | /* mlock MCL_FUTURE? */ |
971 | if (vm_flags & VM_LOCKED) { | |
972 | unsigned long locked, lock_limit; | |
93ea1d0a CW |
973 | locked = len >> PAGE_SHIFT; |
974 | locked += mm->locked_vm; | |
59e99e5b | 975 | lock_limit = rlimit(RLIMIT_MEMLOCK); |
93ea1d0a | 976 | lock_limit >>= PAGE_SHIFT; |
1da177e4 LT |
977 | if (locked > lock_limit && !capable(CAP_IPC_LOCK)) |
978 | return -EAGAIN; | |
979 | } | |
980 | ||
d3ac7f89 | 981 | inode = file ? file->f_path.dentry->d_inode : NULL; |
1da177e4 LT |
982 | |
983 | if (file) { | |
984 | switch (flags & MAP_TYPE) { | |
985 | case MAP_SHARED: | |
986 | if ((prot&PROT_WRITE) && !(file->f_mode&FMODE_WRITE)) | |
987 | return -EACCES; | |
988 | ||
989 | /* | |
990 | * Make sure we don't allow writing to an append-only | |
991 | * file.. | |
992 | */ | |
993 | if (IS_APPEND(inode) && (file->f_mode & FMODE_WRITE)) | |
994 | return -EACCES; | |
995 | ||
996 | /* | |
997 | * Make sure there are no mandatory locks on the file. | |
998 | */ | |
999 | if (locks_verify_locked(inode)) | |
1000 | return -EAGAIN; | |
1001 | ||
1002 | vm_flags |= VM_SHARED | VM_MAYSHARE; | |
1003 | if (!(file->f_mode & FMODE_WRITE)) | |
1004 | vm_flags &= ~(VM_MAYWRITE | VM_SHARED); | |
1005 | ||
1006 | /* fall through */ | |
1007 | case MAP_PRIVATE: | |
1008 | if (!(file->f_mode & FMODE_READ)) | |
1009 | return -EACCES; | |
d3ac7f89 | 1010 | if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) { |
80c5606c LT |
1011 | if (vm_flags & VM_EXEC) |
1012 | return -EPERM; | |
1013 | vm_flags &= ~VM_MAYEXEC; | |
1014 | } | |
80c5606c LT |
1015 | |
1016 | if (!file->f_op || !file->f_op->mmap) | |
1017 | return -ENODEV; | |
1da177e4 LT |
1018 | break; |
1019 | ||
1020 | default: | |
1021 | return -EINVAL; | |
1022 | } | |
1023 | } else { | |
1024 | switch (flags & MAP_TYPE) { | |
1025 | case MAP_SHARED: | |
ce363942 TH |
1026 | /* |
1027 | * Ignore pgoff. | |
1028 | */ | |
1029 | pgoff = 0; | |
1da177e4 LT |
1030 | vm_flags |= VM_SHARED | VM_MAYSHARE; |
1031 | break; | |
1032 | case MAP_PRIVATE: | |
1033 | /* | |
1034 | * Set pgoff according to addr for anon_vma. | |
1035 | */ | |
1036 | pgoff = addr >> PAGE_SHIFT; | |
1037 | break; | |
1038 | default: | |
1039 | return -EINVAL; | |
1040 | } | |
1041 | } | |
1042 | ||
ed032189 | 1043 | error = security_file_mmap(file, reqprot, prot, flags, addr, 0); |
1da177e4 LT |
1044 | if (error) |
1045 | return error; | |
ed032189 | 1046 | |
5a6fe125 | 1047 | return mmap_region(file, addr, len, flags, vm_flags, pgoff); |
0165ab44 MS |
1048 | } |
1049 | EXPORT_SYMBOL(do_mmap_pgoff); | |
1050 | ||
66f0dc48 HD |
1051 | SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len, |
1052 | unsigned long, prot, unsigned long, flags, | |
1053 | unsigned long, fd, unsigned long, pgoff) | |
1054 | { | |
1055 | struct file *file = NULL; | |
1056 | unsigned long retval = -EBADF; | |
1057 | ||
1058 | if (!(flags & MAP_ANONYMOUS)) { | |
1059 | if (unlikely(flags & MAP_HUGETLB)) | |
1060 | return -EINVAL; | |
1061 | file = fget(fd); | |
1062 | if (!file) | |
1063 | goto out; | |
1064 | } else if (flags & MAP_HUGETLB) { | |
1065 | struct user_struct *user = NULL; | |
1066 | /* | |
1067 | * VM_NORESERVE is used because the reservations will be | |
1068 | * taken when vm_ops->mmap() is called | |
1069 | * A dummy user value is used because we are not locking | |
1070 | * memory so no accounting is necessary | |
1071 | */ | |
1072 | len = ALIGN(len, huge_page_size(&default_hstate)); | |
1073 | file = hugetlb_file_setup(HUGETLB_ANON_FILE, len, VM_NORESERVE, | |
1074 | &user, HUGETLB_ANONHUGE_INODE); | |
1075 | if (IS_ERR(file)) | |
1076 | return PTR_ERR(file); | |
1077 | } | |
1078 | ||
1079 | flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE); | |
1080 | ||
1081 | down_write(¤t->mm->mmap_sem); | |
1082 | retval = do_mmap_pgoff(file, addr, len, prot, flags, pgoff); | |
1083 | up_write(¤t->mm->mmap_sem); | |
1084 | ||
1085 | if (file) | |
1086 | fput(file); | |
1087 | out: | |
1088 | return retval; | |
1089 | } | |
1090 | ||
4e950f6f AD |
1091 | /* |
1092 | * Some shared mappigns will want the pages marked read-only | |
1093 | * to track write events. If so, we'll downgrade vm_page_prot | |
1094 | * to the private version (using protection_map[] without the | |
1095 | * VM_SHARED bit). | |
1096 | */ | |
1097 | int vma_wants_writenotify(struct vm_area_struct *vma) | |
1098 | { | |
1099 | unsigned int vm_flags = vma->vm_flags; | |
1100 | ||
1101 | /* If it was private or non-writable, the write bit is already clear */ | |
1102 | if ((vm_flags & (VM_WRITE|VM_SHARED)) != ((VM_WRITE|VM_SHARED))) | |
1103 | return 0; | |
1104 | ||
1105 | /* The backer wishes to know when pages are first written to? */ | |
1106 | if (vma->vm_ops && vma->vm_ops->page_mkwrite) | |
1107 | return 1; | |
1108 | ||
1109 | /* The open routine did something to the protections already? */ | |
1110 | if (pgprot_val(vma->vm_page_prot) != | |
3ed75eb8 | 1111 | pgprot_val(vm_get_page_prot(vm_flags))) |
4e950f6f AD |
1112 | return 0; |
1113 | ||
1114 | /* Specialty mapping? */ | |
1115 | if (vm_flags & (VM_PFNMAP|VM_INSERTPAGE)) | |
1116 | return 0; | |
1117 | ||
1118 | /* Can the mapping track the dirty pages? */ | |
1119 | return vma->vm_file && vma->vm_file->f_mapping && | |
1120 | mapping_cap_account_dirty(vma->vm_file->f_mapping); | |
1121 | } | |
1122 | ||
fc8744ad LT |
1123 | /* |
1124 | * We account for memory if it's a private writeable mapping, | |
5a6fe125 | 1125 | * not hugepages and VM_NORESERVE wasn't set. |
fc8744ad | 1126 | */ |
5a6fe125 | 1127 | static inline int accountable_mapping(struct file *file, unsigned int vm_flags) |
fc8744ad | 1128 | { |
5a6fe125 MG |
1129 | /* |
1130 | * hugetlb has its own accounting separate from the core VM | |
1131 | * VM_HUGETLB may not be set yet so we cannot check for that flag. | |
1132 | */ | |
1133 | if (file && is_file_hugepages(file)) | |
1134 | return 0; | |
1135 | ||
fc8744ad LT |
1136 | return (vm_flags & (VM_NORESERVE | VM_SHARED | VM_WRITE)) == VM_WRITE; |
1137 | } | |
1138 | ||
0165ab44 MS |
1139 | unsigned long mmap_region(struct file *file, unsigned long addr, |
1140 | unsigned long len, unsigned long flags, | |
5a6fe125 | 1141 | unsigned int vm_flags, unsigned long pgoff) |
0165ab44 MS |
1142 | { |
1143 | struct mm_struct *mm = current->mm; | |
1144 | struct vm_area_struct *vma, *prev; | |
1145 | int correct_wcount = 0; | |
1146 | int error; | |
1147 | struct rb_node **rb_link, *rb_parent; | |
1148 | unsigned long charged = 0; | |
1149 | struct inode *inode = file ? file->f_path.dentry->d_inode : NULL; | |
1150 | ||
1da177e4 LT |
1151 | /* Clear old maps */ |
1152 | error = -ENOMEM; | |
1153 | munmap_back: | |
1154 | vma = find_vma_prepare(mm, addr, &prev, &rb_link, &rb_parent); | |
1155 | if (vma && vma->vm_start < addr + len) { | |
1156 | if (do_munmap(mm, addr, len)) | |
1157 | return -ENOMEM; | |
1158 | goto munmap_back; | |
1159 | } | |
1160 | ||
1161 | /* Check against address space limit. */ | |
119f657c | 1162 | if (!may_expand_vm(mm, len >> PAGE_SHIFT)) |
1da177e4 LT |
1163 | return -ENOMEM; |
1164 | ||
fc8744ad LT |
1165 | /* |
1166 | * Set 'VM_NORESERVE' if we should not account for the | |
5a6fe125 | 1167 | * memory use of this mapping. |
fc8744ad | 1168 | */ |
5a6fe125 MG |
1169 | if ((flags & MAP_NORESERVE)) { |
1170 | /* We honor MAP_NORESERVE if allowed to overcommit */ | |
1171 | if (sysctl_overcommit_memory != OVERCOMMIT_NEVER) | |
1172 | vm_flags |= VM_NORESERVE; | |
1173 | ||
1174 | /* hugetlb applies strict overcommit unless MAP_NORESERVE */ | |
1175 | if (file && is_file_hugepages(file)) | |
1176 | vm_flags |= VM_NORESERVE; | |
1177 | } | |
cdfd4325 | 1178 | |
fc8744ad LT |
1179 | /* |
1180 | * Private writable mapping: check memory availability | |
1181 | */ | |
5a6fe125 | 1182 | if (accountable_mapping(file, vm_flags)) { |
fc8744ad LT |
1183 | charged = len >> PAGE_SHIFT; |
1184 | if (security_vm_enough_memory(charged)) | |
1185 | return -ENOMEM; | |
1186 | vm_flags |= VM_ACCOUNT; | |
1da177e4 LT |
1187 | } |
1188 | ||
1189 | /* | |
de33c8db | 1190 | * Can we just expand an old mapping? |
1da177e4 | 1191 | */ |
de33c8db LT |
1192 | vma = vma_merge(mm, prev, addr, addr + len, vm_flags, NULL, file, pgoff, NULL); |
1193 | if (vma) | |
1194 | goto out; | |
1da177e4 LT |
1195 | |
1196 | /* | |
1197 | * Determine the object being mapped and call the appropriate | |
1198 | * specific mapper. the address has already been validated, but | |
1199 | * not unmapped, but the maps are removed from the list. | |
1200 | */ | |
c5e3b83e | 1201 | vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL); |
1da177e4 LT |
1202 | if (!vma) { |
1203 | error = -ENOMEM; | |
1204 | goto unacct_error; | |
1205 | } | |
1da177e4 LT |
1206 | |
1207 | vma->vm_mm = mm; | |
1208 | vma->vm_start = addr; | |
1209 | vma->vm_end = addr + len; | |
1210 | vma->vm_flags = vm_flags; | |
3ed75eb8 | 1211 | vma->vm_page_prot = vm_get_page_prot(vm_flags); |
1da177e4 | 1212 | vma->vm_pgoff = pgoff; |
5beb4930 | 1213 | INIT_LIST_HEAD(&vma->anon_vma_chain); |
1da177e4 LT |
1214 | |
1215 | if (file) { | |
1216 | error = -EINVAL; | |
1217 | if (vm_flags & (VM_GROWSDOWN|VM_GROWSUP)) | |
1218 | goto free_vma; | |
1219 | if (vm_flags & VM_DENYWRITE) { | |
1220 | error = deny_write_access(file); | |
1221 | if (error) | |
1222 | goto free_vma; | |
1223 | correct_wcount = 1; | |
1224 | } | |
1225 | vma->vm_file = file; | |
1226 | get_file(file); | |
1227 | error = file->f_op->mmap(file, vma); | |
1228 | if (error) | |
1229 | goto unmap_and_free_vma; | |
925d1c40 MH |
1230 | if (vm_flags & VM_EXECUTABLE) |
1231 | added_exe_file_vma(mm); | |
f8dbf0a7 HS |
1232 | |
1233 | /* Can addr have changed?? | |
1234 | * | |
1235 | * Answer: Yes, several device drivers can do it in their | |
1236 | * f_op->mmap method. -DaveM | |
1237 | */ | |
1238 | addr = vma->vm_start; | |
1239 | pgoff = vma->vm_pgoff; | |
1240 | vm_flags = vma->vm_flags; | |
1da177e4 LT |
1241 | } else if (vm_flags & VM_SHARED) { |
1242 | error = shmem_zero_setup(vma); | |
1243 | if (error) | |
1244 | goto free_vma; | |
1245 | } | |
1246 | ||
c9d0bf24 MD |
1247 | if (vma_wants_writenotify(vma)) { |
1248 | pgprot_t pprot = vma->vm_page_prot; | |
1249 | ||
1250 | /* Can vma->vm_page_prot have changed?? | |
1251 | * | |
1252 | * Answer: Yes, drivers may have changed it in their | |
1253 | * f_op->mmap method. | |
1254 | * | |
1255 | * Ensures that vmas marked as uncached stay that way. | |
1256 | */ | |
1ddd439e | 1257 | vma->vm_page_prot = vm_get_page_prot(vm_flags & ~VM_SHARED); |
c9d0bf24 MD |
1258 | if (pgprot_val(pprot) == pgprot_val(pgprot_noncached(pprot))) |
1259 | vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); | |
1260 | } | |
d08b3851 | 1261 | |
de33c8db LT |
1262 | vma_link(mm, vma, prev, rb_link, rb_parent); |
1263 | file = vma->vm_file; | |
4d3d5b41 ON |
1264 | |
1265 | /* Once vma denies write, undo our temporary denial count */ | |
1266 | if (correct_wcount) | |
1267 | atomic_inc(&inode->i_writecount); | |
1268 | out: | |
cdd6c482 | 1269 | perf_event_mmap(vma); |
0a4a9391 | 1270 | |
1da177e4 | 1271 | mm->total_vm += len >> PAGE_SHIFT; |
ab50b8ed | 1272 | vm_stat_account(mm, vm_flags, file, len >> PAGE_SHIFT); |
1da177e4 | 1273 | if (vm_flags & VM_LOCKED) { |
06f9d8c2 KM |
1274 | if (!mlock_vma_pages_range(vma, addr, addr + len)) |
1275 | mm->locked_vm += (len >> PAGE_SHIFT); | |
ba470de4 | 1276 | } else if ((flags & MAP_POPULATE) && !(flags & MAP_NONBLOCK)) |
54cb8821 | 1277 | make_pages_present(addr, addr + len); |
1da177e4 LT |
1278 | return addr; |
1279 | ||
1280 | unmap_and_free_vma: | |
1281 | if (correct_wcount) | |
1282 | atomic_inc(&inode->i_writecount); | |
1283 | vma->vm_file = NULL; | |
1284 | fput(file); | |
1285 | ||
1286 | /* Undo any partial mapping done by a device driver. */ | |
e0da382c HD |
1287 | unmap_region(mm, vma, prev, vma->vm_start, vma->vm_end); |
1288 | charged = 0; | |
1da177e4 LT |
1289 | free_vma: |
1290 | kmem_cache_free(vm_area_cachep, vma); | |
1291 | unacct_error: | |
1292 | if (charged) | |
1293 | vm_unacct_memory(charged); | |
1294 | return error; | |
1295 | } | |
1296 | ||
1da177e4 LT |
1297 | /* Get an address range which is currently unmapped. |
1298 | * For shmat() with addr=0. | |
1299 | * | |
1300 | * Ugly calling convention alert: | |
1301 | * Return value with the low bits set means error value, | |
1302 | * ie | |
1303 | * if (ret & ~PAGE_MASK) | |
1304 | * error = ret; | |
1305 | * | |
1306 | * This function "knows" that -ENOMEM has the bits set. | |
1307 | */ | |
1308 | #ifndef HAVE_ARCH_UNMAPPED_AREA | |
1309 | unsigned long | |
1310 | arch_get_unmapped_area(struct file *filp, unsigned long addr, | |
1311 | unsigned long len, unsigned long pgoff, unsigned long flags) | |
1312 | { | |
1313 | struct mm_struct *mm = current->mm; | |
1314 | struct vm_area_struct *vma; | |
1315 | unsigned long start_addr; | |
1316 | ||
1317 | if (len > TASK_SIZE) | |
1318 | return -ENOMEM; | |
1319 | ||
06abdfb4 BH |
1320 | if (flags & MAP_FIXED) |
1321 | return addr; | |
1322 | ||
1da177e4 LT |
1323 | if (addr) { |
1324 | addr = PAGE_ALIGN(addr); | |
1325 | vma = find_vma(mm, addr); | |
1326 | if (TASK_SIZE - len >= addr && | |
1327 | (!vma || addr + len <= vma->vm_start)) | |
1328 | return addr; | |
1329 | } | |
1363c3cd WW |
1330 | if (len > mm->cached_hole_size) { |
1331 | start_addr = addr = mm->free_area_cache; | |
1332 | } else { | |
1333 | start_addr = addr = TASK_UNMAPPED_BASE; | |
1334 | mm->cached_hole_size = 0; | |
1335 | } | |
1da177e4 LT |
1336 | |
1337 | full_search: | |
1338 | for (vma = find_vma(mm, addr); ; vma = vma->vm_next) { | |
1339 | /* At this point: (!vma || addr < vma->vm_end). */ | |
1340 | if (TASK_SIZE - len < addr) { | |
1341 | /* | |
1342 | * Start a new search - just in case we missed | |
1343 | * some holes. | |
1344 | */ | |
1345 | if (start_addr != TASK_UNMAPPED_BASE) { | |
1363c3cd WW |
1346 | addr = TASK_UNMAPPED_BASE; |
1347 | start_addr = addr; | |
1348 | mm->cached_hole_size = 0; | |
1da177e4 LT |
1349 | goto full_search; |
1350 | } | |
1351 | return -ENOMEM; | |
1352 | } | |
1353 | if (!vma || addr + len <= vma->vm_start) { | |
1354 | /* | |
1355 | * Remember the place where we stopped the search: | |
1356 | */ | |
1357 | mm->free_area_cache = addr + len; | |
1358 | return addr; | |
1359 | } | |
1363c3cd WW |
1360 | if (addr + mm->cached_hole_size < vma->vm_start) |
1361 | mm->cached_hole_size = vma->vm_start - addr; | |
1da177e4 LT |
1362 | addr = vma->vm_end; |
1363 | } | |
1364 | } | |
1365 | #endif | |
1366 | ||
1363c3cd | 1367 | void arch_unmap_area(struct mm_struct *mm, unsigned long addr) |
1da177e4 LT |
1368 | { |
1369 | /* | |
1370 | * Is this a new hole at the lowest possible address? | |
1371 | */ | |
1363c3cd WW |
1372 | if (addr >= TASK_UNMAPPED_BASE && addr < mm->free_area_cache) { |
1373 | mm->free_area_cache = addr; | |
1374 | mm->cached_hole_size = ~0UL; | |
1375 | } | |
1da177e4 LT |
1376 | } |
1377 | ||
1378 | /* | |
1379 | * This mmap-allocator allocates new areas top-down from below the | |
1380 | * stack's low limit (the base): | |
1381 | */ | |
1382 | #ifndef HAVE_ARCH_UNMAPPED_AREA_TOPDOWN | |
1383 | unsigned long | |
1384 | arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, | |
1385 | const unsigned long len, const unsigned long pgoff, | |
1386 | const unsigned long flags) | |
1387 | { | |
1388 | struct vm_area_struct *vma; | |
1389 | struct mm_struct *mm = current->mm; | |
1390 | unsigned long addr = addr0; | |
1391 | ||
1392 | /* requested length too big for entire address space */ | |
1393 | if (len > TASK_SIZE) | |
1394 | return -ENOMEM; | |
1395 | ||
06abdfb4 BH |
1396 | if (flags & MAP_FIXED) |
1397 | return addr; | |
1398 | ||
1da177e4 LT |
1399 | /* requesting a specific address */ |
1400 | if (addr) { | |
1401 | addr = PAGE_ALIGN(addr); | |
1402 | vma = find_vma(mm, addr); | |
1403 | if (TASK_SIZE - len >= addr && | |
1404 | (!vma || addr + len <= vma->vm_start)) | |
1405 | return addr; | |
1406 | } | |
1407 | ||
1363c3cd WW |
1408 | /* check if free_area_cache is useful for us */ |
1409 | if (len <= mm->cached_hole_size) { | |
1410 | mm->cached_hole_size = 0; | |
1411 | mm->free_area_cache = mm->mmap_base; | |
1412 | } | |
1413 | ||
1da177e4 LT |
1414 | /* either no address requested or can't fit in requested address hole */ |
1415 | addr = mm->free_area_cache; | |
1416 | ||
1417 | /* make sure it can fit in the remaining address space */ | |
49a43876 | 1418 | if (addr > len) { |
1da177e4 LT |
1419 | vma = find_vma(mm, addr-len); |
1420 | if (!vma || addr <= vma->vm_start) | |
1421 | /* remember the address as a hint for next time */ | |
1422 | return (mm->free_area_cache = addr-len); | |
1423 | } | |
1424 | ||
73219d17 CW |
1425 | if (mm->mmap_base < len) |
1426 | goto bottomup; | |
1427 | ||
1da177e4 LT |
1428 | addr = mm->mmap_base-len; |
1429 | ||
1430 | do { | |
1431 | /* | |
1432 | * Lookup failure means no vma is above this address, | |
1433 | * else if new region fits below vma->vm_start, | |
1434 | * return with success: | |
1435 | */ | |
1436 | vma = find_vma(mm, addr); | |
1437 | if (!vma || addr+len <= vma->vm_start) | |
1438 | /* remember the address as a hint for next time */ | |
1439 | return (mm->free_area_cache = addr); | |
1440 | ||
1363c3cd WW |
1441 | /* remember the largest hole we saw so far */ |
1442 | if (addr + mm->cached_hole_size < vma->vm_start) | |
1443 | mm->cached_hole_size = vma->vm_start - addr; | |
1444 | ||
1da177e4 LT |
1445 | /* try just below the current vma->vm_start */ |
1446 | addr = vma->vm_start-len; | |
49a43876 | 1447 | } while (len < vma->vm_start); |
1da177e4 | 1448 | |
73219d17 | 1449 | bottomup: |
1da177e4 LT |
1450 | /* |
1451 | * A failed mmap() very likely causes application failure, | |
1452 | * so fall back to the bottom-up function here. This scenario | |
1453 | * can happen with large stack limits and large mmap() | |
1454 | * allocations. | |
1455 | */ | |
1363c3cd WW |
1456 | mm->cached_hole_size = ~0UL; |
1457 | mm->free_area_cache = TASK_UNMAPPED_BASE; | |
1da177e4 LT |
1458 | addr = arch_get_unmapped_area(filp, addr0, len, pgoff, flags); |
1459 | /* | |
1460 | * Restore the topdown base: | |
1461 | */ | |
1462 | mm->free_area_cache = mm->mmap_base; | |
1363c3cd | 1463 | mm->cached_hole_size = ~0UL; |
1da177e4 LT |
1464 | |
1465 | return addr; | |
1466 | } | |
1467 | #endif | |
1468 | ||
1363c3cd | 1469 | void arch_unmap_area_topdown(struct mm_struct *mm, unsigned long addr) |
1da177e4 LT |
1470 | { |
1471 | /* | |
1472 | * Is this a new hole at the highest possible address? | |
1473 | */ | |
1363c3cd WW |
1474 | if (addr > mm->free_area_cache) |
1475 | mm->free_area_cache = addr; | |
1da177e4 LT |
1476 | |
1477 | /* dont allow allocations above current base */ | |
1363c3cd WW |
1478 | if (mm->free_area_cache > mm->mmap_base) |
1479 | mm->free_area_cache = mm->mmap_base; | |
1da177e4 LT |
1480 | } |
1481 | ||
1482 | unsigned long | |
1483 | get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, | |
1484 | unsigned long pgoff, unsigned long flags) | |
1485 | { | |
06abdfb4 BH |
1486 | unsigned long (*get_area)(struct file *, unsigned long, |
1487 | unsigned long, unsigned long, unsigned long); | |
1488 | ||
9206de95 AV |
1489 | unsigned long error = arch_mmap_check(addr, len, flags); |
1490 | if (error) | |
1491 | return error; | |
1492 | ||
1493 | /* Careful about overflows.. */ | |
1494 | if (len > TASK_SIZE) | |
1495 | return -ENOMEM; | |
1496 | ||
06abdfb4 BH |
1497 | get_area = current->mm->get_unmapped_area; |
1498 | if (file && file->f_op && file->f_op->get_unmapped_area) | |
1499 | get_area = file->f_op->get_unmapped_area; | |
1500 | addr = get_area(file, addr, len, pgoff, flags); | |
1501 | if (IS_ERR_VALUE(addr)) | |
1502 | return addr; | |
1da177e4 | 1503 | |
07ab67c8 LT |
1504 | if (addr > TASK_SIZE - len) |
1505 | return -ENOMEM; | |
1506 | if (addr & ~PAGE_MASK) | |
1507 | return -EINVAL; | |
06abdfb4 | 1508 | |
08e7d9b5 | 1509 | return arch_rebalance_pgtables(addr, len); |
1da177e4 LT |
1510 | } |
1511 | ||
1512 | EXPORT_SYMBOL(get_unmapped_area); | |
1513 | ||
1514 | /* Look up the first VMA which satisfies addr < vm_end, NULL if none. */ | |
48aae425 | 1515 | struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) |
1da177e4 LT |
1516 | { |
1517 | struct vm_area_struct *vma = NULL; | |
1518 | ||
1519 | if (mm) { | |
1520 | /* Check the cache first. */ | |
1521 | /* (Cache hit rate is typically around 35%.) */ | |
1522 | vma = mm->mmap_cache; | |
1523 | if (!(vma && vma->vm_end > addr && vma->vm_start <= addr)) { | |
1524 | struct rb_node * rb_node; | |
1525 | ||
1526 | rb_node = mm->mm_rb.rb_node; | |
1527 | vma = NULL; | |
1528 | ||
1529 | while (rb_node) { | |
1530 | struct vm_area_struct * vma_tmp; | |
1531 | ||
1532 | vma_tmp = rb_entry(rb_node, | |
1533 | struct vm_area_struct, vm_rb); | |
1534 | ||
1535 | if (vma_tmp->vm_end > addr) { | |
1536 | vma = vma_tmp; | |
1537 | if (vma_tmp->vm_start <= addr) | |
1538 | break; | |
1539 | rb_node = rb_node->rb_left; | |
1540 | } else | |
1541 | rb_node = rb_node->rb_right; | |
1542 | } | |
1543 | if (vma) | |
1544 | mm->mmap_cache = vma; | |
1545 | } | |
1546 | } | |
1547 | return vma; | |
1548 | } | |
1549 | ||
1550 | EXPORT_SYMBOL(find_vma); | |
1551 | ||
1552 | /* Same as find_vma, but also return a pointer to the previous VMA in *pprev. */ | |
1553 | struct vm_area_struct * | |
1554 | find_vma_prev(struct mm_struct *mm, unsigned long addr, | |
1555 | struct vm_area_struct **pprev) | |
1556 | { | |
1557 | struct vm_area_struct *vma = NULL, *prev = NULL; | |
48aae425 | 1558 | struct rb_node *rb_node; |
1da177e4 LT |
1559 | if (!mm) |
1560 | goto out; | |
1561 | ||
1562 | /* Guard against addr being lower than the first VMA */ | |
1563 | vma = mm->mmap; | |
1564 | ||
1565 | /* Go through the RB tree quickly. */ | |
1566 | rb_node = mm->mm_rb.rb_node; | |
1567 | ||
1568 | while (rb_node) { | |
1569 | struct vm_area_struct *vma_tmp; | |
1570 | vma_tmp = rb_entry(rb_node, struct vm_area_struct, vm_rb); | |
1571 | ||
1572 | if (addr < vma_tmp->vm_end) { | |
1573 | rb_node = rb_node->rb_left; | |
1574 | } else { | |
1575 | prev = vma_tmp; | |
1576 | if (!prev->vm_next || (addr < prev->vm_next->vm_end)) | |
1577 | break; | |
1578 | rb_node = rb_node->rb_right; | |
1579 | } | |
1580 | } | |
1581 | ||
1582 | out: | |
1583 | *pprev = prev; | |
1584 | return prev ? prev->vm_next : vma; | |
1585 | } | |
1586 | ||
1587 | /* | |
1588 | * Verify that the stack growth is acceptable and | |
1589 | * update accounting. This is shared with both the | |
1590 | * grow-up and grow-down cases. | |
1591 | */ | |
48aae425 | 1592 | static int acct_stack_growth(struct vm_area_struct *vma, unsigned long size, unsigned long grow) |
1da177e4 LT |
1593 | { |
1594 | struct mm_struct *mm = vma->vm_mm; | |
1595 | struct rlimit *rlim = current->signal->rlim; | |
0d59a01b | 1596 | unsigned long new_start; |
1da177e4 LT |
1597 | |
1598 | /* address space limit tests */ | |
119f657c | 1599 | if (!may_expand_vm(mm, grow)) |
1da177e4 LT |
1600 | return -ENOMEM; |
1601 | ||
1602 | /* Stack limit test */ | |
59e99e5b | 1603 | if (size > ACCESS_ONCE(rlim[RLIMIT_STACK].rlim_cur)) |
1da177e4 LT |
1604 | return -ENOMEM; |
1605 | ||
1606 | /* mlock limit tests */ | |
1607 | if (vma->vm_flags & VM_LOCKED) { | |
1608 | unsigned long locked; | |
1609 | unsigned long limit; | |
1610 | locked = mm->locked_vm + grow; | |
59e99e5b JS |
1611 | limit = ACCESS_ONCE(rlim[RLIMIT_MEMLOCK].rlim_cur); |
1612 | limit >>= PAGE_SHIFT; | |
1da177e4 LT |
1613 | if (locked > limit && !capable(CAP_IPC_LOCK)) |
1614 | return -ENOMEM; | |
1615 | } | |
1616 | ||
0d59a01b AL |
1617 | /* Check to ensure the stack will not grow into a hugetlb-only region */ |
1618 | new_start = (vma->vm_flags & VM_GROWSUP) ? vma->vm_start : | |
1619 | vma->vm_end - size; | |
1620 | if (is_hugepage_only_range(vma->vm_mm, new_start, size)) | |
1621 | return -EFAULT; | |
1622 | ||
1da177e4 LT |
1623 | /* |
1624 | * Overcommit.. This must be the final test, as it will | |
1625 | * update security statistics. | |
1626 | */ | |
05fa199d | 1627 | if (security_vm_enough_memory_mm(mm, grow)) |
1da177e4 LT |
1628 | return -ENOMEM; |
1629 | ||
1630 | /* Ok, everything looks good - let it rip */ | |
1631 | mm->total_vm += grow; | |
1632 | if (vma->vm_flags & VM_LOCKED) | |
1633 | mm->locked_vm += grow; | |
ab50b8ed | 1634 | vm_stat_account(mm, vma->vm_flags, vma->vm_file, grow); |
1da177e4 LT |
1635 | return 0; |
1636 | } | |
1637 | ||
46dea3d0 | 1638 | #if defined(CONFIG_STACK_GROWSUP) || defined(CONFIG_IA64) |
1da177e4 | 1639 | /* |
46dea3d0 HD |
1640 | * PA-RISC uses this for its stack; IA64 for its Register Backing Store. |
1641 | * vma is the last one with address > vma->vm_end. Have to extend vma. | |
1da177e4 | 1642 | */ |
9ab88515 | 1643 | #ifndef CONFIG_IA64 |
cb8f488c | 1644 | static |
46dea3d0 HD |
1645 | #endif |
1646 | int expand_upwards(struct vm_area_struct *vma, unsigned long address) | |
1da177e4 LT |
1647 | { |
1648 | int error; | |
1649 | ||
1650 | if (!(vma->vm_flags & VM_GROWSUP)) | |
1651 | return -EFAULT; | |
1652 | ||
1653 | /* | |
1654 | * We must make sure the anon_vma is allocated | |
1655 | * so that the anon_vma locking is not a noop. | |
1656 | */ | |
1657 | if (unlikely(anon_vma_prepare(vma))) | |
1658 | return -ENOMEM; | |
1659 | anon_vma_lock(vma); | |
1660 | ||
1661 | /* | |
1662 | * vma->vm_start/vm_end cannot change under us because the caller | |
1663 | * is required to hold the mmap_sem in read mode. We need the | |
1664 | * anon_vma lock to serialize against concurrent expand_stacks. | |
06b32f3a | 1665 | * Also guard against wrapping around to address 0. |
1da177e4 | 1666 | */ |
06b32f3a HD |
1667 | if (address < PAGE_ALIGN(address+4)) |
1668 | address = PAGE_ALIGN(address+4); | |
1669 | else { | |
1670 | anon_vma_unlock(vma); | |
1671 | return -ENOMEM; | |
1672 | } | |
1da177e4 LT |
1673 | error = 0; |
1674 | ||
1675 | /* Somebody else might have raced and expanded it already */ | |
1676 | if (address > vma->vm_end) { | |
1677 | unsigned long size, grow; | |
1678 | ||
1679 | size = address - vma->vm_start; | |
1680 | grow = (address - vma->vm_end) >> PAGE_SHIFT; | |
1681 | ||
1682 | error = acct_stack_growth(vma, size, grow); | |
1683 | if (!error) | |
1684 | vma->vm_end = address; | |
1685 | } | |
1686 | anon_vma_unlock(vma); | |
1687 | return error; | |
1688 | } | |
46dea3d0 HD |
1689 | #endif /* CONFIG_STACK_GROWSUP || CONFIG_IA64 */ |
1690 | ||
1da177e4 LT |
1691 | /* |
1692 | * vma is the first one with address < vma->vm_start. Have to extend vma. | |
1693 | */ | |
cb8f488c | 1694 | static int expand_downwards(struct vm_area_struct *vma, |
b6a2fea3 | 1695 | unsigned long address) |
1da177e4 LT |
1696 | { |
1697 | int error; | |
1698 | ||
1699 | /* | |
1700 | * We must make sure the anon_vma is allocated | |
1701 | * so that the anon_vma locking is not a noop. | |
1702 | */ | |
1703 | if (unlikely(anon_vma_prepare(vma))) | |
1704 | return -ENOMEM; | |
8869477a EP |
1705 | |
1706 | address &= PAGE_MASK; | |
88c3f7a8 | 1707 | error = security_file_mmap(NULL, 0, 0, 0, address, 1); |
8869477a EP |
1708 | if (error) |
1709 | return error; | |
1710 | ||
1da177e4 LT |
1711 | anon_vma_lock(vma); |
1712 | ||
1713 | /* | |
1714 | * vma->vm_start/vm_end cannot change under us because the caller | |
1715 | * is required to hold the mmap_sem in read mode. We need the | |
1716 | * anon_vma lock to serialize against concurrent expand_stacks. | |
1717 | */ | |
1da177e4 LT |
1718 | |
1719 | /* Somebody else might have raced and expanded it already */ | |
1720 | if (address < vma->vm_start) { | |
1721 | unsigned long size, grow; | |
1722 | ||
1723 | size = vma->vm_end - address; | |
1724 | grow = (vma->vm_start - address) >> PAGE_SHIFT; | |
1725 | ||
1726 | error = acct_stack_growth(vma, size, grow); | |
1727 | if (!error) { | |
1728 | vma->vm_start = address; | |
1729 | vma->vm_pgoff -= grow; | |
1730 | } | |
1731 | } | |
1732 | anon_vma_unlock(vma); | |
1733 | return error; | |
1734 | } | |
1735 | ||
b6a2fea3 OW |
1736 | int expand_stack_downwards(struct vm_area_struct *vma, unsigned long address) |
1737 | { | |
1738 | return expand_downwards(vma, address); | |
1739 | } | |
1740 | ||
1741 | #ifdef CONFIG_STACK_GROWSUP | |
1742 | int expand_stack(struct vm_area_struct *vma, unsigned long address) | |
1743 | { | |
1744 | return expand_upwards(vma, address); | |
1745 | } | |
1746 | ||
1747 | struct vm_area_struct * | |
1748 | find_extend_vma(struct mm_struct *mm, unsigned long addr) | |
1749 | { | |
1750 | struct vm_area_struct *vma, *prev; | |
1751 | ||
1752 | addr &= PAGE_MASK; | |
1753 | vma = find_vma_prev(mm, addr, &prev); | |
1754 | if (vma && (vma->vm_start <= addr)) | |
1755 | return vma; | |
1c127185 | 1756 | if (!prev || expand_stack(prev, addr)) |
b6a2fea3 | 1757 | return NULL; |
ba470de4 | 1758 | if (prev->vm_flags & VM_LOCKED) { |
c58267c3 | 1759 | mlock_vma_pages_range(prev, addr, prev->vm_end); |
ba470de4 | 1760 | } |
b6a2fea3 OW |
1761 | return prev; |
1762 | } | |
1763 | #else | |
1764 | int expand_stack(struct vm_area_struct *vma, unsigned long address) | |
1765 | { | |
1766 | return expand_downwards(vma, address); | |
1767 | } | |
1768 | ||
1da177e4 LT |
1769 | struct vm_area_struct * |
1770 | find_extend_vma(struct mm_struct * mm, unsigned long addr) | |
1771 | { | |
1772 | struct vm_area_struct * vma; | |
1773 | unsigned long start; | |
1774 | ||
1775 | addr &= PAGE_MASK; | |
1776 | vma = find_vma(mm,addr); | |
1777 | if (!vma) | |
1778 | return NULL; | |
1779 | if (vma->vm_start <= addr) | |
1780 | return vma; | |
1781 | if (!(vma->vm_flags & VM_GROWSDOWN)) | |
1782 | return NULL; | |
1783 | start = vma->vm_start; | |
1784 | if (expand_stack(vma, addr)) | |
1785 | return NULL; | |
ba470de4 | 1786 | if (vma->vm_flags & VM_LOCKED) { |
c58267c3 | 1787 | mlock_vma_pages_range(vma, addr, start); |
ba470de4 | 1788 | } |
1da177e4 LT |
1789 | return vma; |
1790 | } | |
1791 | #endif | |
1792 | ||
1da177e4 | 1793 | /* |
2c0b3814 | 1794 | * Ok - we have the memory areas we should free on the vma list, |
1da177e4 | 1795 | * so release them, and do the vma updates. |
2c0b3814 HD |
1796 | * |
1797 | * Called with the mm semaphore held. | |
1da177e4 | 1798 | */ |
2c0b3814 | 1799 | static void remove_vma_list(struct mm_struct *mm, struct vm_area_struct *vma) |
1da177e4 | 1800 | { |
365e9c87 HD |
1801 | /* Update high watermark before we lower total_vm */ |
1802 | update_hiwater_vm(mm); | |
1da177e4 | 1803 | do { |
2c0b3814 HD |
1804 | long nrpages = vma_pages(vma); |
1805 | ||
1806 | mm->total_vm -= nrpages; | |
2c0b3814 | 1807 | vm_stat_account(mm, vma->vm_flags, vma->vm_file, -nrpages); |
a8fb5618 | 1808 | vma = remove_vma(vma); |
146425a3 | 1809 | } while (vma); |
1da177e4 LT |
1810 | validate_mm(mm); |
1811 | } | |
1812 | ||
1813 | /* | |
1814 | * Get rid of page table information in the indicated region. | |
1815 | * | |
f10df686 | 1816 | * Called with the mm semaphore held. |
1da177e4 LT |
1817 | */ |
1818 | static void unmap_region(struct mm_struct *mm, | |
e0da382c HD |
1819 | struct vm_area_struct *vma, struct vm_area_struct *prev, |
1820 | unsigned long start, unsigned long end) | |
1da177e4 | 1821 | { |
e0da382c | 1822 | struct vm_area_struct *next = prev? prev->vm_next: mm->mmap; |
1da177e4 LT |
1823 | struct mmu_gather *tlb; |
1824 | unsigned long nr_accounted = 0; | |
1825 | ||
1826 | lru_add_drain(); | |
1827 | tlb = tlb_gather_mmu(mm, 0); | |
365e9c87 | 1828 | update_hiwater_rss(mm); |
508034a3 | 1829 | unmap_vmas(&tlb, vma, start, end, &nr_accounted, NULL); |
1da177e4 | 1830 | vm_unacct_memory(nr_accounted); |
42b77728 | 1831 | free_pgtables(tlb, vma, prev? prev->vm_end: FIRST_USER_ADDRESS, |
e0da382c | 1832 | next? next->vm_start: 0); |
1da177e4 LT |
1833 | tlb_finish_mmu(tlb, start, end); |
1834 | } | |
1835 | ||
1836 | /* | |
1837 | * Create a list of vma's touched by the unmap, removing them from the mm's | |
1838 | * vma list as we go.. | |
1839 | */ | |
1840 | static void | |
1841 | detach_vmas_to_be_unmapped(struct mm_struct *mm, struct vm_area_struct *vma, | |
1842 | struct vm_area_struct *prev, unsigned long end) | |
1843 | { | |
1844 | struct vm_area_struct **insertion_point; | |
1845 | struct vm_area_struct *tail_vma = NULL; | |
1363c3cd | 1846 | unsigned long addr; |
1da177e4 LT |
1847 | |
1848 | insertion_point = (prev ? &prev->vm_next : &mm->mmap); | |
1849 | do { | |
1850 | rb_erase(&vma->vm_rb, &mm->mm_rb); | |
1851 | mm->map_count--; | |
1852 | tail_vma = vma; | |
1853 | vma = vma->vm_next; | |
1854 | } while (vma && vma->vm_start < end); | |
1855 | *insertion_point = vma; | |
1856 | tail_vma->vm_next = NULL; | |
1363c3cd WW |
1857 | if (mm->unmap_area == arch_unmap_area) |
1858 | addr = prev ? prev->vm_end : mm->mmap_base; | |
1859 | else | |
1860 | addr = vma ? vma->vm_start : mm->mmap_base; | |
1861 | mm->unmap_area(mm, addr); | |
1da177e4 LT |
1862 | mm->mmap_cache = NULL; /* Kill the cache. */ |
1863 | } | |
1864 | ||
1865 | /* | |
659ace58 KM |
1866 | * __split_vma() bypasses sysctl_max_map_count checking. We use this on the |
1867 | * munmap path where it doesn't make sense to fail. | |
1da177e4 | 1868 | */ |
659ace58 | 1869 | static int __split_vma(struct mm_struct * mm, struct vm_area_struct * vma, |
1da177e4 LT |
1870 | unsigned long addr, int new_below) |
1871 | { | |
1872 | struct mempolicy *pol; | |
1873 | struct vm_area_struct *new; | |
5beb4930 | 1874 | int err = -ENOMEM; |
1da177e4 | 1875 | |
a5516438 AK |
1876 | if (is_vm_hugetlb_page(vma) && (addr & |
1877 | ~(huge_page_mask(hstate_vma(vma))))) | |
1da177e4 LT |
1878 | return -EINVAL; |
1879 | ||
e94b1766 | 1880 | new = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL); |
1da177e4 | 1881 | if (!new) |
5beb4930 | 1882 | goto out_err; |
1da177e4 LT |
1883 | |
1884 | /* most fields are the same, copy all, and then fixup */ | |
1885 | *new = *vma; | |
1886 | ||
5beb4930 RR |
1887 | INIT_LIST_HEAD(&new->anon_vma_chain); |
1888 | ||
1da177e4 LT |
1889 | if (new_below) |
1890 | new->vm_end = addr; | |
1891 | else { | |
1892 | new->vm_start = addr; | |
1893 | new->vm_pgoff += ((addr - vma->vm_start) >> PAGE_SHIFT); | |
1894 | } | |
1895 | ||
846a16bf | 1896 | pol = mpol_dup(vma_policy(vma)); |
1da177e4 | 1897 | if (IS_ERR(pol)) { |
5beb4930 RR |
1898 | err = PTR_ERR(pol); |
1899 | goto out_free_vma; | |
1da177e4 LT |
1900 | } |
1901 | vma_set_policy(new, pol); | |
1902 | ||
5beb4930 RR |
1903 | if (anon_vma_clone(new, vma)) |
1904 | goto out_free_mpol; | |
1905 | ||
925d1c40 | 1906 | if (new->vm_file) { |
1da177e4 | 1907 | get_file(new->vm_file); |
925d1c40 MH |
1908 | if (vma->vm_flags & VM_EXECUTABLE) |
1909 | added_exe_file_vma(mm); | |
1910 | } | |
1da177e4 LT |
1911 | |
1912 | if (new->vm_ops && new->vm_ops->open) | |
1913 | new->vm_ops->open(new); | |
1914 | ||
1915 | if (new_below) | |
5beb4930 | 1916 | err = vma_adjust(vma, addr, vma->vm_end, vma->vm_pgoff + |
1da177e4 LT |
1917 | ((addr - new->vm_start) >> PAGE_SHIFT), new); |
1918 | else | |
5beb4930 | 1919 | err = vma_adjust(vma, vma->vm_start, addr, vma->vm_pgoff, new); |
1da177e4 | 1920 | |
5beb4930 RR |
1921 | /* Success. */ |
1922 | if (!err) | |
1923 | return 0; | |
1924 | ||
1925 | /* Clean everything up if vma_adjust failed. */ | |
1926 | new->vm_ops->close(new); | |
1927 | if (new->vm_file) { | |
1928 | if (vma->vm_flags & VM_EXECUTABLE) | |
1929 | removed_exe_file_vma(mm); | |
1930 | fput(new->vm_file); | |
1931 | } | |
1932 | out_free_mpol: | |
1933 | mpol_put(pol); | |
1934 | out_free_vma: | |
1935 | kmem_cache_free(vm_area_cachep, new); | |
1936 | out_err: | |
1937 | return err; | |
1da177e4 LT |
1938 | } |
1939 | ||
659ace58 KM |
1940 | /* |
1941 | * Split a vma into two pieces at address 'addr', a new vma is allocated | |
1942 | * either for the first part or the tail. | |
1943 | */ | |
1944 | int split_vma(struct mm_struct *mm, struct vm_area_struct *vma, | |
1945 | unsigned long addr, int new_below) | |
1946 | { | |
1947 | if (mm->map_count >= sysctl_max_map_count) | |
1948 | return -ENOMEM; | |
1949 | ||
1950 | return __split_vma(mm, vma, addr, new_below); | |
1951 | } | |
1952 | ||
1da177e4 LT |
1953 | /* Munmap is split into 2 main parts -- this part which finds |
1954 | * what needs doing, and the areas themselves, which do the | |
1955 | * work. This now handles partial unmappings. | |
1956 | * Jeremy Fitzhardinge <jeremy@goop.org> | |
1957 | */ | |
1958 | int do_munmap(struct mm_struct *mm, unsigned long start, size_t len) | |
1959 | { | |
1960 | unsigned long end; | |
146425a3 | 1961 | struct vm_area_struct *vma, *prev, *last; |
1da177e4 LT |
1962 | |
1963 | if ((start & ~PAGE_MASK) || start > TASK_SIZE || len > TASK_SIZE-start) | |
1964 | return -EINVAL; | |
1965 | ||
1966 | if ((len = PAGE_ALIGN(len)) == 0) | |
1967 | return -EINVAL; | |
1968 | ||
1969 | /* Find the first overlapping VMA */ | |
146425a3 HD |
1970 | vma = find_vma_prev(mm, start, &prev); |
1971 | if (!vma) | |
1da177e4 | 1972 | return 0; |
146425a3 | 1973 | /* we have start < vma->vm_end */ |
1da177e4 LT |
1974 | |
1975 | /* if it doesn't overlap, we have nothing.. */ | |
1976 | end = start + len; | |
146425a3 | 1977 | if (vma->vm_start >= end) |
1da177e4 LT |
1978 | return 0; |
1979 | ||
1980 | /* | |
1981 | * If we need to split any vma, do it now to save pain later. | |
1982 | * | |
1983 | * Note: mremap's move_vma VM_ACCOUNT handling assumes a partially | |
1984 | * unmapped vm_area_struct will remain in use: so lower split_vma | |
1985 | * places tmp vma above, and higher split_vma places tmp vma below. | |
1986 | */ | |
146425a3 | 1987 | if (start > vma->vm_start) { |
659ace58 KM |
1988 | int error; |
1989 | ||
1990 | /* | |
1991 | * Make sure that map_count on return from munmap() will | |
1992 | * not exceed its limit; but let map_count go just above | |
1993 | * its limit temporarily, to help free resources as expected. | |
1994 | */ | |
1995 | if (end < vma->vm_end && mm->map_count >= sysctl_max_map_count) | |
1996 | return -ENOMEM; | |
1997 | ||
1998 | error = __split_vma(mm, vma, start, 0); | |
1da177e4 LT |
1999 | if (error) |
2000 | return error; | |
146425a3 | 2001 | prev = vma; |
1da177e4 LT |
2002 | } |
2003 | ||
2004 | /* Does it split the last one? */ | |
2005 | last = find_vma(mm, end); | |
2006 | if (last && end > last->vm_start) { | |
659ace58 | 2007 | int error = __split_vma(mm, last, end, 1); |
1da177e4 LT |
2008 | if (error) |
2009 | return error; | |
2010 | } | |
146425a3 | 2011 | vma = prev? prev->vm_next: mm->mmap; |
1da177e4 | 2012 | |
ba470de4 RR |
2013 | /* |
2014 | * unlock any mlock()ed ranges before detaching vmas | |
2015 | */ | |
2016 | if (mm->locked_vm) { | |
2017 | struct vm_area_struct *tmp = vma; | |
2018 | while (tmp && tmp->vm_start < end) { | |
2019 | if (tmp->vm_flags & VM_LOCKED) { | |
2020 | mm->locked_vm -= vma_pages(tmp); | |
2021 | munlock_vma_pages_all(tmp); | |
2022 | } | |
2023 | tmp = tmp->vm_next; | |
2024 | } | |
2025 | } | |
2026 | ||
1da177e4 LT |
2027 | /* |
2028 | * Remove the vma's, and unmap the actual pages | |
2029 | */ | |
146425a3 HD |
2030 | detach_vmas_to_be_unmapped(mm, vma, prev, end); |
2031 | unmap_region(mm, vma, prev, start, end); | |
1da177e4 LT |
2032 | |
2033 | /* Fix up all other VM information */ | |
2c0b3814 | 2034 | remove_vma_list(mm, vma); |
1da177e4 LT |
2035 | |
2036 | return 0; | |
2037 | } | |
2038 | ||
2039 | EXPORT_SYMBOL(do_munmap); | |
2040 | ||
6a6160a7 | 2041 | SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len) |
1da177e4 LT |
2042 | { |
2043 | int ret; | |
2044 | struct mm_struct *mm = current->mm; | |
2045 | ||
2046 | profile_munmap(addr); | |
2047 | ||
2048 | down_write(&mm->mmap_sem); | |
2049 | ret = do_munmap(mm, addr, len); | |
2050 | up_write(&mm->mmap_sem); | |
2051 | return ret; | |
2052 | } | |
2053 | ||
2054 | static inline void verify_mm_writelocked(struct mm_struct *mm) | |
2055 | { | |
a241ec65 | 2056 | #ifdef CONFIG_DEBUG_VM |
1da177e4 LT |
2057 | if (unlikely(down_read_trylock(&mm->mmap_sem))) { |
2058 | WARN_ON(1); | |
2059 | up_read(&mm->mmap_sem); | |
2060 | } | |
2061 | #endif | |
2062 | } | |
2063 | ||
2064 | /* | |
2065 | * this is really a simplified "do_mmap". it only handles | |
2066 | * anonymous maps. eventually we may be able to do some | |
2067 | * brk-specific accounting here. | |
2068 | */ | |
2069 | unsigned long do_brk(unsigned long addr, unsigned long len) | |
2070 | { | |
2071 | struct mm_struct * mm = current->mm; | |
2072 | struct vm_area_struct * vma, * prev; | |
2073 | unsigned long flags; | |
2074 | struct rb_node ** rb_link, * rb_parent; | |
2075 | pgoff_t pgoff = addr >> PAGE_SHIFT; | |
3a459756 | 2076 | int error; |
1da177e4 LT |
2077 | |
2078 | len = PAGE_ALIGN(len); | |
2079 | if (!len) | |
2080 | return addr; | |
2081 | ||
88c3f7a8 | 2082 | error = security_file_mmap(NULL, 0, 0, 0, addr, 1); |
5a211a5d EP |
2083 | if (error) |
2084 | return error; | |
2085 | ||
3a459756 KK |
2086 | flags = VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags; |
2087 | ||
2c6a1016 AV |
2088 | error = get_unmapped_area(NULL, addr, len, 0, MAP_FIXED); |
2089 | if (error & ~PAGE_MASK) | |
3a459756 KK |
2090 | return error; |
2091 | ||
1da177e4 LT |
2092 | /* |
2093 | * mlock MCL_FUTURE? | |
2094 | */ | |
2095 | if (mm->def_flags & VM_LOCKED) { | |
2096 | unsigned long locked, lock_limit; | |
93ea1d0a CW |
2097 | locked = len >> PAGE_SHIFT; |
2098 | locked += mm->locked_vm; | |
59e99e5b | 2099 | lock_limit = rlimit(RLIMIT_MEMLOCK); |
93ea1d0a | 2100 | lock_limit >>= PAGE_SHIFT; |
1da177e4 LT |
2101 | if (locked > lock_limit && !capable(CAP_IPC_LOCK)) |
2102 | return -EAGAIN; | |
2103 | } | |
2104 | ||
2105 | /* | |
2106 | * mm->mmap_sem is required to protect against another thread | |
2107 | * changing the mappings in case we sleep. | |
2108 | */ | |
2109 | verify_mm_writelocked(mm); | |
2110 | ||
2111 | /* | |
2112 | * Clear old maps. this also does some error checking for us | |
2113 | */ | |
2114 | munmap_back: | |
2115 | vma = find_vma_prepare(mm, addr, &prev, &rb_link, &rb_parent); | |
2116 | if (vma && vma->vm_start < addr + len) { | |
2117 | if (do_munmap(mm, addr, len)) | |
2118 | return -ENOMEM; | |
2119 | goto munmap_back; | |
2120 | } | |
2121 | ||
2122 | /* Check against address space limits *after* clearing old maps... */ | |
119f657c | 2123 | if (!may_expand_vm(mm, len >> PAGE_SHIFT)) |
1da177e4 LT |
2124 | return -ENOMEM; |
2125 | ||
2126 | if (mm->map_count > sysctl_max_map_count) | |
2127 | return -ENOMEM; | |
2128 | ||
2129 | if (security_vm_enough_memory(len >> PAGE_SHIFT)) | |
2130 | return -ENOMEM; | |
2131 | ||
1da177e4 | 2132 | /* Can we just expand an old private anonymous mapping? */ |
ba470de4 RR |
2133 | vma = vma_merge(mm, prev, addr, addr + len, flags, |
2134 | NULL, NULL, pgoff, NULL); | |
2135 | if (vma) | |
1da177e4 LT |
2136 | goto out; |
2137 | ||
2138 | /* | |
2139 | * create a vma struct for an anonymous mapping | |
2140 | */ | |
c5e3b83e | 2141 | vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL); |
1da177e4 LT |
2142 | if (!vma) { |
2143 | vm_unacct_memory(len >> PAGE_SHIFT); | |
2144 | return -ENOMEM; | |
2145 | } | |
1da177e4 | 2146 | |
5beb4930 | 2147 | INIT_LIST_HEAD(&vma->anon_vma_chain); |
1da177e4 LT |
2148 | vma->vm_mm = mm; |
2149 | vma->vm_start = addr; | |
2150 | vma->vm_end = addr + len; | |
2151 | vma->vm_pgoff = pgoff; | |
2152 | vma->vm_flags = flags; | |
3ed75eb8 | 2153 | vma->vm_page_prot = vm_get_page_prot(flags); |
1da177e4 LT |
2154 | vma_link(mm, vma, prev, rb_link, rb_parent); |
2155 | out: | |
2156 | mm->total_vm += len >> PAGE_SHIFT; | |
2157 | if (flags & VM_LOCKED) { | |
ba470de4 RR |
2158 | if (!mlock_vma_pages_range(vma, addr, addr + len)) |
2159 | mm->locked_vm += (len >> PAGE_SHIFT); | |
1da177e4 LT |
2160 | } |
2161 | return addr; | |
2162 | } | |
2163 | ||
2164 | EXPORT_SYMBOL(do_brk); | |
2165 | ||
2166 | /* Release all mmaps. */ | |
2167 | void exit_mmap(struct mm_struct *mm) | |
2168 | { | |
2169 | struct mmu_gather *tlb; | |
ba470de4 | 2170 | struct vm_area_struct *vma; |
1da177e4 | 2171 | unsigned long nr_accounted = 0; |
ee39b37b | 2172 | unsigned long end; |
1da177e4 | 2173 | |
d6dd61c8 | 2174 | /* mm's last user has gone, and its about to be pulled down */ |
cddb8a5c | 2175 | mmu_notifier_release(mm); |
d6dd61c8 | 2176 | |
ba470de4 RR |
2177 | if (mm->locked_vm) { |
2178 | vma = mm->mmap; | |
2179 | while (vma) { | |
2180 | if (vma->vm_flags & VM_LOCKED) | |
2181 | munlock_vma_pages_all(vma); | |
2182 | vma = vma->vm_next; | |
2183 | } | |
2184 | } | |
9480c53e JF |
2185 | |
2186 | arch_exit_mmap(mm); | |
2187 | ||
ba470de4 | 2188 | vma = mm->mmap; |
9480c53e JF |
2189 | if (!vma) /* Can happen if dup_mmap() received an OOM */ |
2190 | return; | |
2191 | ||
1da177e4 | 2192 | lru_add_drain(); |
1da177e4 | 2193 | flush_cache_mm(mm); |
e0da382c | 2194 | tlb = tlb_gather_mmu(mm, 1); |
901608d9 | 2195 | /* update_hiwater_rss(mm) here? but nobody should be looking */ |
e0da382c | 2196 | /* Use -1 here to ensure all VMAs in the mm are unmapped */ |
508034a3 | 2197 | end = unmap_vmas(&tlb, vma, 0, -1, &nr_accounted, NULL); |
1da177e4 | 2198 | vm_unacct_memory(nr_accounted); |
9ba69294 | 2199 | |
42b77728 | 2200 | free_pgtables(tlb, vma, FIRST_USER_ADDRESS, 0); |
ee39b37b | 2201 | tlb_finish_mmu(tlb, 0, end); |
1da177e4 | 2202 | |
1da177e4 | 2203 | /* |
8f4f8c16 HD |
2204 | * Walk the list again, actually closing and freeing it, |
2205 | * with preemption enabled, without holding any MM locks. | |
1da177e4 | 2206 | */ |
a8fb5618 HD |
2207 | while (vma) |
2208 | vma = remove_vma(vma); | |
e0da382c | 2209 | |
e2cdef8c | 2210 | BUG_ON(mm->nr_ptes > (FIRST_USER_ADDRESS+PMD_SIZE-1)>>PMD_SHIFT); |
1da177e4 LT |
2211 | } |
2212 | ||
2213 | /* Insert vm structure into process list sorted by address | |
2214 | * and into the inode's i_mmap tree. If vm_file is non-NULL | |
2215 | * then i_mmap_lock is taken here. | |
2216 | */ | |
2217 | int insert_vm_struct(struct mm_struct * mm, struct vm_area_struct * vma) | |
2218 | { | |
2219 | struct vm_area_struct * __vma, * prev; | |
2220 | struct rb_node ** rb_link, * rb_parent; | |
2221 | ||
2222 | /* | |
2223 | * The vm_pgoff of a purely anonymous vma should be irrelevant | |
2224 | * until its first write fault, when page's anon_vma and index | |
2225 | * are set. But now set the vm_pgoff it will almost certainly | |
2226 | * end up with (unless mremap moves it elsewhere before that | |
2227 | * first wfault), so /proc/pid/maps tells a consistent story. | |
2228 | * | |
2229 | * By setting it to reflect the virtual start address of the | |
2230 | * vma, merges and splits can happen in a seamless way, just | |
2231 | * using the existing file pgoff checks and manipulations. | |
2232 | * Similarly in do_mmap_pgoff and in do_brk. | |
2233 | */ | |
2234 | if (!vma->vm_file) { | |
2235 | BUG_ON(vma->anon_vma); | |
2236 | vma->vm_pgoff = vma->vm_start >> PAGE_SHIFT; | |
2237 | } | |
2238 | __vma = find_vma_prepare(mm,vma->vm_start,&prev,&rb_link,&rb_parent); | |
2239 | if (__vma && __vma->vm_start < vma->vm_end) | |
2240 | return -ENOMEM; | |
2fd4ef85 | 2241 | if ((vma->vm_flags & VM_ACCOUNT) && |
34b4e4aa | 2242 | security_vm_enough_memory_mm(mm, vma_pages(vma))) |
2fd4ef85 | 2243 | return -ENOMEM; |
1da177e4 LT |
2244 | vma_link(mm, vma, prev, rb_link, rb_parent); |
2245 | return 0; | |
2246 | } | |
2247 | ||
2248 | /* | |
2249 | * Copy the vma structure to a new location in the same mm, | |
2250 | * prior to moving page table entries, to effect an mremap move. | |
2251 | */ | |
2252 | struct vm_area_struct *copy_vma(struct vm_area_struct **vmap, | |
2253 | unsigned long addr, unsigned long len, pgoff_t pgoff) | |
2254 | { | |
2255 | struct vm_area_struct *vma = *vmap; | |
2256 | unsigned long vma_start = vma->vm_start; | |
2257 | struct mm_struct *mm = vma->vm_mm; | |
2258 | struct vm_area_struct *new_vma, *prev; | |
2259 | struct rb_node **rb_link, *rb_parent; | |
2260 | struct mempolicy *pol; | |
2261 | ||
2262 | /* | |
2263 | * If anonymous vma has not yet been faulted, update new pgoff | |
2264 | * to match new location, to increase its chance of merging. | |
2265 | */ | |
2266 | if (!vma->vm_file && !vma->anon_vma) | |
2267 | pgoff = addr >> PAGE_SHIFT; | |
2268 | ||
2269 | find_vma_prepare(mm, addr, &prev, &rb_link, &rb_parent); | |
2270 | new_vma = vma_merge(mm, prev, addr, addr + len, vma->vm_flags, | |
2271 | vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma)); | |
2272 | if (new_vma) { | |
2273 | /* | |
2274 | * Source vma may have been merged into new_vma | |
2275 | */ | |
2276 | if (vma_start >= new_vma->vm_start && | |
2277 | vma_start < new_vma->vm_end) | |
2278 | *vmap = new_vma; | |
2279 | } else { | |
e94b1766 | 2280 | new_vma = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL); |
1da177e4 LT |
2281 | if (new_vma) { |
2282 | *new_vma = *vma; | |
846a16bf | 2283 | pol = mpol_dup(vma_policy(vma)); |
5beb4930 RR |
2284 | if (IS_ERR(pol)) |
2285 | goto out_free_vma; | |
2286 | INIT_LIST_HEAD(&new_vma->anon_vma_chain); | |
2287 | if (anon_vma_clone(new_vma, vma)) | |
2288 | goto out_free_mempol; | |
1da177e4 LT |
2289 | vma_set_policy(new_vma, pol); |
2290 | new_vma->vm_start = addr; | |
2291 | new_vma->vm_end = addr + len; | |
2292 | new_vma->vm_pgoff = pgoff; | |
925d1c40 | 2293 | if (new_vma->vm_file) { |
1da177e4 | 2294 | get_file(new_vma->vm_file); |
925d1c40 MH |
2295 | if (vma->vm_flags & VM_EXECUTABLE) |
2296 | added_exe_file_vma(mm); | |
2297 | } | |
1da177e4 LT |
2298 | if (new_vma->vm_ops && new_vma->vm_ops->open) |
2299 | new_vma->vm_ops->open(new_vma); | |
2300 | vma_link(mm, new_vma, prev, rb_link, rb_parent); | |
2301 | } | |
2302 | } | |
2303 | return new_vma; | |
5beb4930 RR |
2304 | |
2305 | out_free_mempol: | |
2306 | mpol_put(pol); | |
2307 | out_free_vma: | |
2308 | kmem_cache_free(vm_area_cachep, new_vma); | |
2309 | return NULL; | |
1da177e4 | 2310 | } |
119f657c | 2311 | |
2312 | /* | |
2313 | * Return true if the calling process may expand its vm space by the passed | |
2314 | * number of pages | |
2315 | */ | |
2316 | int may_expand_vm(struct mm_struct *mm, unsigned long npages) | |
2317 | { | |
2318 | unsigned long cur = mm->total_vm; /* pages */ | |
2319 | unsigned long lim; | |
2320 | ||
59e99e5b | 2321 | lim = rlimit(RLIMIT_AS) >> PAGE_SHIFT; |
119f657c | 2322 | |
2323 | if (cur + npages > lim) | |
2324 | return 0; | |
2325 | return 1; | |
2326 | } | |
fa5dc22f RM |
2327 | |
2328 | ||
b1d0e4f5 NP |
2329 | static int special_mapping_fault(struct vm_area_struct *vma, |
2330 | struct vm_fault *vmf) | |
fa5dc22f | 2331 | { |
b1d0e4f5 | 2332 | pgoff_t pgoff; |
fa5dc22f RM |
2333 | struct page **pages; |
2334 | ||
b1d0e4f5 NP |
2335 | /* |
2336 | * special mappings have no vm_file, and in that case, the mm | |
2337 | * uses vm_pgoff internally. So we have to subtract it from here. | |
2338 | * We are allowed to do this because we are the mm; do not copy | |
2339 | * this code into drivers! | |
2340 | */ | |
2341 | pgoff = vmf->pgoff - vma->vm_pgoff; | |
fa5dc22f | 2342 | |
b1d0e4f5 NP |
2343 | for (pages = vma->vm_private_data; pgoff && *pages; ++pages) |
2344 | pgoff--; | |
fa5dc22f RM |
2345 | |
2346 | if (*pages) { | |
2347 | struct page *page = *pages; | |
2348 | get_page(page); | |
b1d0e4f5 NP |
2349 | vmf->page = page; |
2350 | return 0; | |
fa5dc22f RM |
2351 | } |
2352 | ||
b1d0e4f5 | 2353 | return VM_FAULT_SIGBUS; |
fa5dc22f RM |
2354 | } |
2355 | ||
2356 | /* | |
2357 | * Having a close hook prevents vma merging regardless of flags. | |
2358 | */ | |
2359 | static void special_mapping_close(struct vm_area_struct *vma) | |
2360 | { | |
2361 | } | |
2362 | ||
f0f37e2f | 2363 | static const struct vm_operations_struct special_mapping_vmops = { |
fa5dc22f | 2364 | .close = special_mapping_close, |
b1d0e4f5 | 2365 | .fault = special_mapping_fault, |
fa5dc22f RM |
2366 | }; |
2367 | ||
2368 | /* | |
2369 | * Called with mm->mmap_sem held for writing. | |
2370 | * Insert a new vma covering the given region, with the given flags. | |
2371 | * Its pages are supplied by the given array of struct page *. | |
2372 | * The array can be shorter than len >> PAGE_SHIFT if it's null-terminated. | |
2373 | * The region past the last page supplied will always produce SIGBUS. | |
2374 | * The array pointer and the pages it points to are assumed to stay alive | |
2375 | * for as long as this mapping might exist. | |
2376 | */ | |
2377 | int install_special_mapping(struct mm_struct *mm, | |
2378 | unsigned long addr, unsigned long len, | |
2379 | unsigned long vm_flags, struct page **pages) | |
2380 | { | |
2381 | struct vm_area_struct *vma; | |
2382 | ||
2383 | vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL); | |
2384 | if (unlikely(vma == NULL)) | |
2385 | return -ENOMEM; | |
2386 | ||
5beb4930 | 2387 | INIT_LIST_HEAD(&vma->anon_vma_chain); |
fa5dc22f RM |
2388 | vma->vm_mm = mm; |
2389 | vma->vm_start = addr; | |
2390 | vma->vm_end = addr + len; | |
2391 | ||
2f98735c | 2392 | vma->vm_flags = vm_flags | mm->def_flags | VM_DONTEXPAND; |
3ed75eb8 | 2393 | vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); |
fa5dc22f RM |
2394 | |
2395 | vma->vm_ops = &special_mapping_vmops; | |
2396 | vma->vm_private_data = pages; | |
2397 | ||
2398 | if (unlikely(insert_vm_struct(mm, vma))) { | |
2399 | kmem_cache_free(vm_area_cachep, vma); | |
2400 | return -ENOMEM; | |
2401 | } | |
2402 | ||
2403 | mm->total_vm += len >> PAGE_SHIFT; | |
2404 | ||
cdd6c482 | 2405 | perf_event_mmap(vma); |
089dd79d | 2406 | |
fa5dc22f RM |
2407 | return 0; |
2408 | } | |
7906d00c AA |
2409 | |
2410 | static DEFINE_MUTEX(mm_all_locks_mutex); | |
2411 | ||
454ed842 | 2412 | static void vm_lock_anon_vma(struct mm_struct *mm, struct anon_vma *anon_vma) |
7906d00c AA |
2413 | { |
2414 | if (!test_bit(0, (unsigned long *) &anon_vma->head.next)) { | |
2415 | /* | |
2416 | * The LSB of head.next can't change from under us | |
2417 | * because we hold the mm_all_locks_mutex. | |
2418 | */ | |
454ed842 | 2419 | spin_lock_nest_lock(&anon_vma->lock, &mm->mmap_sem); |
7906d00c AA |
2420 | /* |
2421 | * We can safely modify head.next after taking the | |
2422 | * anon_vma->lock. If some other vma in this mm shares | |
2423 | * the same anon_vma we won't take it again. | |
2424 | * | |
2425 | * No need of atomic instructions here, head.next | |
2426 | * can't change from under us thanks to the | |
2427 | * anon_vma->lock. | |
2428 | */ | |
2429 | if (__test_and_set_bit(0, (unsigned long *) | |
2430 | &anon_vma->head.next)) | |
2431 | BUG(); | |
2432 | } | |
2433 | } | |
2434 | ||
454ed842 | 2435 | static void vm_lock_mapping(struct mm_struct *mm, struct address_space *mapping) |
7906d00c AA |
2436 | { |
2437 | if (!test_bit(AS_MM_ALL_LOCKS, &mapping->flags)) { | |
2438 | /* | |
2439 | * AS_MM_ALL_LOCKS can't change from under us because | |
2440 | * we hold the mm_all_locks_mutex. | |
2441 | * | |
2442 | * Operations on ->flags have to be atomic because | |
2443 | * even if AS_MM_ALL_LOCKS is stable thanks to the | |
2444 | * mm_all_locks_mutex, there may be other cpus | |
2445 | * changing other bitflags in parallel to us. | |
2446 | */ | |
2447 | if (test_and_set_bit(AS_MM_ALL_LOCKS, &mapping->flags)) | |
2448 | BUG(); | |
454ed842 | 2449 | spin_lock_nest_lock(&mapping->i_mmap_lock, &mm->mmap_sem); |
7906d00c AA |
2450 | } |
2451 | } | |
2452 | ||
2453 | /* | |
2454 | * This operation locks against the VM for all pte/vma/mm related | |
2455 | * operations that could ever happen on a certain mm. This includes | |
2456 | * vmtruncate, try_to_unmap, and all page faults. | |
2457 | * | |
2458 | * The caller must take the mmap_sem in write mode before calling | |
2459 | * mm_take_all_locks(). The caller isn't allowed to release the | |
2460 | * mmap_sem until mm_drop_all_locks() returns. | |
2461 | * | |
2462 | * mmap_sem in write mode is required in order to block all operations | |
2463 | * that could modify pagetables and free pages without need of | |
2464 | * altering the vma layout (for example populate_range() with | |
2465 | * nonlinear vmas). It's also needed in write mode to avoid new | |
2466 | * anon_vmas to be associated with existing vmas. | |
2467 | * | |
2468 | * A single task can't take more than one mm_take_all_locks() in a row | |
2469 | * or it would deadlock. | |
2470 | * | |
2471 | * The LSB in anon_vma->head.next and the AS_MM_ALL_LOCKS bitflag in | |
2472 | * mapping->flags avoid to take the same lock twice, if more than one | |
2473 | * vma in this mm is backed by the same anon_vma or address_space. | |
2474 | * | |
2475 | * We can take all the locks in random order because the VM code | |
2476 | * taking i_mmap_lock or anon_vma->lock outside the mmap_sem never | |
2477 | * takes more than one of them in a row. Secondly we're protected | |
2478 | * against a concurrent mm_take_all_locks() by the mm_all_locks_mutex. | |
2479 | * | |
2480 | * mm_take_all_locks() and mm_drop_all_locks are expensive operations | |
2481 | * that may have to take thousand of locks. | |
2482 | * | |
2483 | * mm_take_all_locks() can fail if it's interrupted by signals. | |
2484 | */ | |
2485 | int mm_take_all_locks(struct mm_struct *mm) | |
2486 | { | |
2487 | struct vm_area_struct *vma; | |
5beb4930 | 2488 | struct anon_vma_chain *avc; |
7906d00c AA |
2489 | int ret = -EINTR; |
2490 | ||
2491 | BUG_ON(down_read_trylock(&mm->mmap_sem)); | |
2492 | ||
2493 | mutex_lock(&mm_all_locks_mutex); | |
2494 | ||
2495 | for (vma = mm->mmap; vma; vma = vma->vm_next) { | |
2496 | if (signal_pending(current)) | |
2497 | goto out_unlock; | |
7906d00c | 2498 | if (vma->vm_file && vma->vm_file->f_mapping) |
454ed842 | 2499 | vm_lock_mapping(mm, vma->vm_file->f_mapping); |
7906d00c | 2500 | } |
7cd5a02f PZ |
2501 | |
2502 | for (vma = mm->mmap; vma; vma = vma->vm_next) { | |
2503 | if (signal_pending(current)) | |
2504 | goto out_unlock; | |
2505 | if (vma->anon_vma) | |
5beb4930 RR |
2506 | list_for_each_entry(avc, &vma->anon_vma_chain, same_vma) |
2507 | vm_lock_anon_vma(mm, avc->anon_vma); | |
7906d00c | 2508 | } |
7cd5a02f | 2509 | |
7906d00c AA |
2510 | ret = 0; |
2511 | ||
2512 | out_unlock: | |
2513 | if (ret) | |
2514 | mm_drop_all_locks(mm); | |
2515 | ||
2516 | return ret; | |
2517 | } | |
2518 | ||
2519 | static void vm_unlock_anon_vma(struct anon_vma *anon_vma) | |
2520 | { | |
2521 | if (test_bit(0, (unsigned long *) &anon_vma->head.next)) { | |
2522 | /* | |
2523 | * The LSB of head.next can't change to 0 from under | |
2524 | * us because we hold the mm_all_locks_mutex. | |
2525 | * | |
2526 | * We must however clear the bitflag before unlocking | |
2527 | * the vma so the users using the anon_vma->head will | |
2528 | * never see our bitflag. | |
2529 | * | |
2530 | * No need of atomic instructions here, head.next | |
2531 | * can't change from under us until we release the | |
2532 | * anon_vma->lock. | |
2533 | */ | |
2534 | if (!__test_and_clear_bit(0, (unsigned long *) | |
2535 | &anon_vma->head.next)) | |
2536 | BUG(); | |
2537 | spin_unlock(&anon_vma->lock); | |
2538 | } | |
2539 | } | |
2540 | ||
2541 | static void vm_unlock_mapping(struct address_space *mapping) | |
2542 | { | |
2543 | if (test_bit(AS_MM_ALL_LOCKS, &mapping->flags)) { | |
2544 | /* | |
2545 | * AS_MM_ALL_LOCKS can't change to 0 from under us | |
2546 | * because we hold the mm_all_locks_mutex. | |
2547 | */ | |
2548 | spin_unlock(&mapping->i_mmap_lock); | |
2549 | if (!test_and_clear_bit(AS_MM_ALL_LOCKS, | |
2550 | &mapping->flags)) | |
2551 | BUG(); | |
2552 | } | |
2553 | } | |
2554 | ||
2555 | /* | |
2556 | * The mmap_sem cannot be released by the caller until | |
2557 | * mm_drop_all_locks() returns. | |
2558 | */ | |
2559 | void mm_drop_all_locks(struct mm_struct *mm) | |
2560 | { | |
2561 | struct vm_area_struct *vma; | |
5beb4930 | 2562 | struct anon_vma_chain *avc; |
7906d00c AA |
2563 | |
2564 | BUG_ON(down_read_trylock(&mm->mmap_sem)); | |
2565 | BUG_ON(!mutex_is_locked(&mm_all_locks_mutex)); | |
2566 | ||
2567 | for (vma = mm->mmap; vma; vma = vma->vm_next) { | |
2568 | if (vma->anon_vma) | |
5beb4930 RR |
2569 | list_for_each_entry(avc, &vma->anon_vma_chain, same_vma) |
2570 | vm_unlock_anon_vma(avc->anon_vma); | |
7906d00c AA |
2571 | if (vma->vm_file && vma->vm_file->f_mapping) |
2572 | vm_unlock_mapping(vma->vm_file->f_mapping); | |
2573 | } | |
2574 | ||
2575 | mutex_unlock(&mm_all_locks_mutex); | |
2576 | } | |
8feae131 DH |
2577 | |
2578 | /* | |
2579 | * initialise the VMA slab | |
2580 | */ | |
2581 | void __init mmap_init(void) | |
2582 | { | |
00a62ce9 KM |
2583 | int ret; |
2584 | ||
2585 | ret = percpu_counter_init(&vm_committed_as, 0); | |
2586 | VM_BUG_ON(ret); | |
8feae131 | 2587 | } |