Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/mm/nommu.c | |
3 | * | |
4 | * Replacement code for mm functions to support CPU's that don't | |
5 | * have any form of memory management unit (thus no virtual memory). | |
6 | * | |
7 | * See Documentation/nommu-mmap.txt | |
8 | * | |
9 | * Copyright (c) 2004-2005 David Howells <dhowells@redhat.com> | |
10 | * Copyright (c) 2000-2003 David McCullough <davidm@snapgear.com> | |
11 | * Copyright (c) 2000-2001 D Jeff Dionne <jeff@uClinux.org> | |
12 | * Copyright (c) 2002 Greg Ungerer <gerg@snapgear.com> | |
13 | */ | |
14 | ||
15 | #include <linux/mm.h> | |
16 | #include <linux/mman.h> | |
17 | #include <linux/swap.h> | |
18 | #include <linux/file.h> | |
19 | #include <linux/highmem.h> | |
20 | #include <linux/pagemap.h> | |
21 | #include <linux/slab.h> | |
22 | #include <linux/vmalloc.h> | |
23 | #include <linux/ptrace.h> | |
24 | #include <linux/blkdev.h> | |
25 | #include <linux/backing-dev.h> | |
26 | #include <linux/mount.h> | |
27 | #include <linux/personality.h> | |
28 | #include <linux/security.h> | |
29 | #include <linux/syscalls.h> | |
30 | ||
31 | #include <asm/uaccess.h> | |
32 | #include <asm/tlb.h> | |
33 | #include <asm/tlbflush.h> | |
34 | ||
35 | void *high_memory; | |
36 | struct page *mem_map; | |
37 | unsigned long max_mapnr; | |
38 | unsigned long num_physpages; | |
39 | unsigned long askedalloc, realalloc; | |
40 | atomic_t vm_committed_space = ATOMIC_INIT(0); | |
41 | int sysctl_overcommit_memory = OVERCOMMIT_GUESS; /* heuristic overcommit */ | |
42 | int sysctl_overcommit_ratio = 50; /* default is 50% */ | |
43 | int sysctl_max_map_count = DEFAULT_MAX_MAP_COUNT; | |
44 | int heap_stack_gap = 0; | |
45 | ||
46 | EXPORT_SYMBOL(mem_map); | |
6a04de6d | 47 | EXPORT_SYMBOL(num_physpages); |
1da177e4 LT |
48 | |
49 | /* list of shareable VMAs */ | |
50 | struct rb_root nommu_vma_tree = RB_ROOT; | |
51 | DECLARE_RWSEM(nommu_vma_sem); | |
52 | ||
53 | struct vm_operations_struct generic_file_vm_ops = { | |
54 | }; | |
55 | ||
56 | /* | |
57 | * Handle all mappings that got truncated by a "truncate()" | |
58 | * system call. | |
59 | * | |
60 | * NOTE! We have to be ready to update the memory sharing | |
61 | * between the file and the memory map for a potential last | |
62 | * incomplete page. Ugly, but necessary. | |
63 | */ | |
64 | int vmtruncate(struct inode *inode, loff_t offset) | |
65 | { | |
66 | struct address_space *mapping = inode->i_mapping; | |
67 | unsigned long limit; | |
68 | ||
69 | if (inode->i_size < offset) | |
70 | goto do_expand; | |
71 | i_size_write(inode, offset); | |
72 | ||
73 | truncate_inode_pages(mapping, offset); | |
74 | goto out_truncate; | |
75 | ||
76 | do_expand: | |
77 | limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur; | |
78 | if (limit != RLIM_INFINITY && offset > limit) | |
79 | goto out_sig; | |
80 | if (offset > inode->i_sb->s_maxbytes) | |
81 | goto out; | |
82 | i_size_write(inode, offset); | |
83 | ||
84 | out_truncate: | |
85 | if (inode->i_op && inode->i_op->truncate) | |
86 | inode->i_op->truncate(inode); | |
87 | return 0; | |
88 | out_sig: | |
89 | send_sig(SIGXFSZ, current, 0); | |
90 | out: | |
91 | return -EFBIG; | |
92 | } | |
93 | ||
94 | EXPORT_SYMBOL(vmtruncate); | |
95 | ||
96 | /* | |
97 | * Return the total memory allocated for this pointer, not | |
98 | * just what the caller asked for. | |
99 | * | |
100 | * Doesn't have to be accurate, i.e. may have races. | |
101 | */ | |
102 | unsigned int kobjsize(const void *objp) | |
103 | { | |
104 | struct page *page; | |
105 | ||
106 | if (!objp || !((page = virt_to_page(objp)))) | |
107 | return 0; | |
108 | ||
109 | if (PageSlab(page)) | |
110 | return ksize(objp); | |
111 | ||
112 | BUG_ON(page->index < 0); | |
113 | BUG_ON(page->index >= MAX_ORDER); | |
114 | ||
115 | return (PAGE_SIZE << page->index); | |
116 | } | |
117 | ||
118 | /* | |
7b4d5b8b DH |
119 | * get a list of pages in an address range belonging to the specified process |
120 | * and indicate the VMA that covers each page | |
121 | * - this is potentially dodgy as we may end incrementing the page count of a | |
122 | * slab page or a secondary page from a compound page | |
123 | * - don't permit access to VMAs that don't support it, such as I/O mappings | |
1da177e4 LT |
124 | */ |
125 | int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, | |
126 | unsigned long start, int len, int write, int force, | |
127 | struct page **pages, struct vm_area_struct **vmas) | |
128 | { | |
910e46da | 129 | struct vm_area_struct *vma; |
7b4d5b8b DH |
130 | unsigned long vm_flags; |
131 | int i; | |
132 | ||
133 | /* calculate required read or write permissions. | |
134 | * - if 'force' is set, we only require the "MAY" flags. | |
135 | */ | |
136 | vm_flags = write ? (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD); | |
137 | vm_flags &= force ? (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE); | |
1da177e4 LT |
138 | |
139 | for (i = 0; i < len; i++) { | |
910e46da | 140 | vma = find_vma(mm, start); |
7b4d5b8b DH |
141 | if (!vma) |
142 | goto finish_or_fault; | |
143 | ||
144 | /* protect what we can, including chardevs */ | |
145 | if (vma->vm_flags & (VM_IO | VM_PFNMAP) || | |
146 | !(vm_flags & vma->vm_flags)) | |
147 | goto finish_or_fault; | |
910e46da | 148 | |
1da177e4 LT |
149 | if (pages) { |
150 | pages[i] = virt_to_page(start); | |
151 | if (pages[i]) | |
152 | page_cache_get(pages[i]); | |
153 | } | |
154 | if (vmas) | |
910e46da | 155 | vmas[i] = vma; |
1da177e4 LT |
156 | start += PAGE_SIZE; |
157 | } | |
7b4d5b8b DH |
158 | |
159 | return i; | |
160 | ||
161 | finish_or_fault: | |
162 | return i ? : -EFAULT; | |
1da177e4 | 163 | } |
66aa2b4b GU |
164 | EXPORT_SYMBOL(get_user_pages); |
165 | ||
1da177e4 LT |
166 | DEFINE_RWLOCK(vmlist_lock); |
167 | struct vm_struct *vmlist; | |
168 | ||
169 | void vfree(void *addr) | |
170 | { | |
171 | kfree(addr); | |
172 | } | |
b5073173 | 173 | EXPORT_SYMBOL(vfree); |
1da177e4 | 174 | |
dd0fc66f | 175 | void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot) |
1da177e4 LT |
176 | { |
177 | /* | |
178 | * kmalloc doesn't like __GFP_HIGHMEM for some reason | |
179 | */ | |
84097518 | 180 | return kmalloc(size, (gfp_mask | __GFP_COMP) & ~__GFP_HIGHMEM); |
1da177e4 | 181 | } |
b5073173 | 182 | EXPORT_SYMBOL(__vmalloc); |
1da177e4 LT |
183 | |
184 | struct page * vmalloc_to_page(void *addr) | |
185 | { | |
186 | return virt_to_page(addr); | |
187 | } | |
b5073173 | 188 | EXPORT_SYMBOL(vmalloc_to_page); |
1da177e4 LT |
189 | |
190 | unsigned long vmalloc_to_pfn(void *addr) | |
191 | { | |
192 | return page_to_pfn(virt_to_page(addr)); | |
193 | } | |
b5073173 | 194 | EXPORT_SYMBOL(vmalloc_to_pfn); |
1da177e4 LT |
195 | |
196 | long vread(char *buf, char *addr, unsigned long count) | |
197 | { | |
198 | memcpy(buf, addr, count); | |
199 | return count; | |
200 | } | |
201 | ||
202 | long vwrite(char *buf, char *addr, unsigned long count) | |
203 | { | |
204 | /* Don't allow overflow */ | |
205 | if ((unsigned long) addr + count < count) | |
206 | count = -(unsigned long) addr; | |
207 | ||
208 | memcpy(addr, buf, count); | |
209 | return(count); | |
210 | } | |
211 | ||
212 | /* | |
213 | * vmalloc - allocate virtually continguos memory | |
214 | * | |
215 | * @size: allocation size | |
216 | * | |
217 | * Allocate enough pages to cover @size from the page level | |
218 | * allocator and map them into continguos kernel virtual space. | |
219 | * | |
c1c8897f | 220 | * For tight control over page level allocator and protection flags |
1da177e4 LT |
221 | * use __vmalloc() instead. |
222 | */ | |
223 | void *vmalloc(unsigned long size) | |
224 | { | |
225 | return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL); | |
226 | } | |
f6138882 AM |
227 | EXPORT_SYMBOL(vmalloc); |
228 | ||
229 | void *vmalloc_node(unsigned long size, int node) | |
230 | { | |
231 | return vmalloc(size); | |
232 | } | |
233 | EXPORT_SYMBOL(vmalloc_node); | |
1da177e4 | 234 | |
b5073173 PM |
235 | /** |
236 | * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) | |
1da177e4 LT |
237 | * @size: allocation size |
238 | * | |
239 | * Allocate enough 32bit PA addressable pages to cover @size from the | |
240 | * page level allocator and map them into continguos kernel virtual space. | |
241 | */ | |
242 | void *vmalloc_32(unsigned long size) | |
243 | { | |
244 | return __vmalloc(size, GFP_KERNEL, PAGE_KERNEL); | |
245 | } | |
b5073173 PM |
246 | EXPORT_SYMBOL(vmalloc_32); |
247 | ||
248 | /** | |
249 | * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory | |
250 | * @size: allocation size | |
251 | * | |
252 | * The resulting memory area is 32bit addressable and zeroed so it can be | |
253 | * mapped to userspace without leaking data. | |
254 | */ | |
255 | void *vmalloc_32_user(unsigned long size) | |
256 | { | |
257 | return __vmalloc(size, GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL); | |
258 | } | |
259 | EXPORT_SYMBOL(vmalloc_32_user); | |
1da177e4 LT |
260 | |
261 | void *vmap(struct page **pages, unsigned int count, unsigned long flags, pgprot_t prot) | |
262 | { | |
263 | BUG(); | |
264 | return NULL; | |
265 | } | |
b5073173 | 266 | EXPORT_SYMBOL(vmap); |
1da177e4 LT |
267 | |
268 | void vunmap(void *addr) | |
269 | { | |
270 | BUG(); | |
271 | } | |
b5073173 | 272 | EXPORT_SYMBOL(vunmap); |
1da177e4 | 273 | |
1eeb66a1 CH |
274 | /* |
275 | * Implement a stub for vmalloc_sync_all() if the architecture chose not to | |
276 | * have one. | |
277 | */ | |
278 | void __attribute__((weak)) vmalloc_sync_all(void) | |
279 | { | |
280 | } | |
281 | ||
b5073173 PM |
282 | int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, |
283 | struct page *page) | |
284 | { | |
285 | return -EINVAL; | |
286 | } | |
287 | EXPORT_SYMBOL(vm_insert_page); | |
288 | ||
1da177e4 LT |
289 | /* |
290 | * sys_brk() for the most part doesn't need the global kernel | |
291 | * lock, except when an application is doing something nasty | |
292 | * like trying to un-brk an area that has already been mapped | |
293 | * to a regular file. in this case, the unmapping will need | |
294 | * to invoke file system routines that need the global lock. | |
295 | */ | |
296 | asmlinkage unsigned long sys_brk(unsigned long brk) | |
297 | { | |
298 | struct mm_struct *mm = current->mm; | |
299 | ||
300 | if (brk < mm->start_brk || brk > mm->context.end_brk) | |
301 | return mm->brk; | |
302 | ||
303 | if (mm->brk == brk) | |
304 | return mm->brk; | |
305 | ||
306 | /* | |
307 | * Always allow shrinking brk | |
308 | */ | |
309 | if (brk <= mm->brk) { | |
310 | mm->brk = brk; | |
311 | return brk; | |
312 | } | |
313 | ||
314 | /* | |
315 | * Ok, looks good - let it rip. | |
316 | */ | |
317 | return mm->brk = brk; | |
318 | } | |
319 | ||
320 | #ifdef DEBUG | |
321 | static void show_process_blocks(void) | |
322 | { | |
323 | struct vm_list_struct *vml; | |
324 | ||
325 | printk("Process blocks %d:", current->pid); | |
326 | ||
327 | for (vml = ¤t->mm->context.vmlist; vml; vml = vml->next) { | |
328 | printk(" %p: %p", vml, vml->vma); | |
329 | if (vml->vma) | |
330 | printk(" (%d @%lx #%d)", | |
331 | kobjsize((void *) vml->vma->vm_start), | |
332 | vml->vma->vm_start, | |
333 | atomic_read(&vml->vma->vm_usage)); | |
334 | printk(vml->next ? " ->" : ".\n"); | |
335 | } | |
336 | } | |
337 | #endif /* DEBUG */ | |
338 | ||
3034097a DH |
339 | /* |
340 | * add a VMA into a process's mm_struct in the appropriate place in the list | |
341 | * - should be called with mm->mmap_sem held writelocked | |
342 | */ | |
343 | static void add_vma_to_mm(struct mm_struct *mm, struct vm_list_struct *vml) | |
344 | { | |
345 | struct vm_list_struct **ppv; | |
346 | ||
347 | for (ppv = ¤t->mm->context.vmlist; *ppv; ppv = &(*ppv)->next) | |
348 | if ((*ppv)->vma->vm_start > vml->vma->vm_start) | |
349 | break; | |
350 | ||
351 | vml->next = *ppv; | |
352 | *ppv = vml; | |
353 | } | |
354 | ||
355 | /* | |
356 | * look up the first VMA in which addr resides, NULL if none | |
357 | * - should be called with mm->mmap_sem at least held readlocked | |
358 | */ | |
359 | struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) | |
360 | { | |
361 | struct vm_list_struct *loop, *vml; | |
362 | ||
363 | /* search the vm_start ordered list */ | |
364 | vml = NULL; | |
365 | for (loop = mm->context.vmlist; loop; loop = loop->next) { | |
366 | if (loop->vma->vm_start > addr) | |
367 | break; | |
368 | vml = loop; | |
369 | } | |
370 | ||
371 | if (vml && vml->vma->vm_end > addr) | |
372 | return vml->vma; | |
373 | ||
374 | return NULL; | |
375 | } | |
376 | EXPORT_SYMBOL(find_vma); | |
377 | ||
930e652a DH |
378 | /* |
379 | * find a VMA | |
380 | * - we don't extend stack VMAs under NOMMU conditions | |
381 | */ | |
382 | struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr) | |
383 | { | |
384 | return find_vma(mm, addr); | |
385 | } | |
386 | ||
57c8f63e GU |
387 | int expand_stack(struct vm_area_struct *vma, unsigned long address) |
388 | { | |
389 | return -ENOMEM; | |
390 | } | |
391 | ||
6fa5f80b DH |
392 | /* |
393 | * look up the first VMA exactly that exactly matches addr | |
394 | * - should be called with mm->mmap_sem at least held readlocked | |
395 | */ | |
396 | static inline struct vm_area_struct *find_vma_exact(struct mm_struct *mm, | |
397 | unsigned long addr) | |
398 | { | |
399 | struct vm_list_struct *vml; | |
400 | ||
401 | /* search the vm_start ordered list */ | |
402 | for (vml = mm->context.vmlist; vml; vml = vml->next) { | |
403 | if (vml->vma->vm_start == addr) | |
404 | return vml->vma; | |
405 | if (vml->vma->vm_start > addr) | |
406 | break; | |
407 | } | |
408 | ||
409 | return NULL; | |
410 | } | |
411 | ||
3034097a DH |
412 | /* |
413 | * find a VMA in the global tree | |
414 | */ | |
1da177e4 LT |
415 | static inline struct vm_area_struct *find_nommu_vma(unsigned long start) |
416 | { | |
417 | struct vm_area_struct *vma; | |
418 | struct rb_node *n = nommu_vma_tree.rb_node; | |
419 | ||
420 | while (n) { | |
421 | vma = rb_entry(n, struct vm_area_struct, vm_rb); | |
422 | ||
423 | if (start < vma->vm_start) | |
424 | n = n->rb_left; | |
425 | else if (start > vma->vm_start) | |
426 | n = n->rb_right; | |
427 | else | |
428 | return vma; | |
429 | } | |
430 | ||
431 | return NULL; | |
432 | } | |
433 | ||
3034097a DH |
434 | /* |
435 | * add a VMA in the global tree | |
436 | */ | |
1da177e4 LT |
437 | static void add_nommu_vma(struct vm_area_struct *vma) |
438 | { | |
439 | struct vm_area_struct *pvma; | |
440 | struct address_space *mapping; | |
441 | struct rb_node **p = &nommu_vma_tree.rb_node; | |
442 | struct rb_node *parent = NULL; | |
443 | ||
444 | /* add the VMA to the mapping */ | |
445 | if (vma->vm_file) { | |
446 | mapping = vma->vm_file->f_mapping; | |
447 | ||
448 | flush_dcache_mmap_lock(mapping); | |
449 | vma_prio_tree_insert(vma, &mapping->i_mmap); | |
450 | flush_dcache_mmap_unlock(mapping); | |
451 | } | |
452 | ||
453 | /* add the VMA to the master list */ | |
454 | while (*p) { | |
455 | parent = *p; | |
456 | pvma = rb_entry(parent, struct vm_area_struct, vm_rb); | |
457 | ||
458 | if (vma->vm_start < pvma->vm_start) { | |
459 | p = &(*p)->rb_left; | |
460 | } | |
461 | else if (vma->vm_start > pvma->vm_start) { | |
462 | p = &(*p)->rb_right; | |
463 | } | |
464 | else { | |
465 | /* mappings are at the same address - this can only | |
466 | * happen for shared-mem chardevs and shared file | |
467 | * mappings backed by ramfs/tmpfs */ | |
468 | BUG_ON(!(pvma->vm_flags & VM_SHARED)); | |
469 | ||
470 | if (vma < pvma) | |
471 | p = &(*p)->rb_left; | |
472 | else if (vma > pvma) | |
473 | p = &(*p)->rb_right; | |
474 | else | |
475 | BUG(); | |
476 | } | |
477 | } | |
478 | ||
479 | rb_link_node(&vma->vm_rb, parent, p); | |
480 | rb_insert_color(&vma->vm_rb, &nommu_vma_tree); | |
481 | } | |
482 | ||
3034097a DH |
483 | /* |
484 | * delete a VMA from the global list | |
485 | */ | |
1da177e4 LT |
486 | static void delete_nommu_vma(struct vm_area_struct *vma) |
487 | { | |
488 | struct address_space *mapping; | |
489 | ||
490 | /* remove the VMA from the mapping */ | |
491 | if (vma->vm_file) { | |
492 | mapping = vma->vm_file->f_mapping; | |
493 | ||
494 | flush_dcache_mmap_lock(mapping); | |
495 | vma_prio_tree_remove(vma, &mapping->i_mmap); | |
496 | flush_dcache_mmap_unlock(mapping); | |
497 | } | |
498 | ||
499 | /* remove from the master list */ | |
500 | rb_erase(&vma->vm_rb, &nommu_vma_tree); | |
501 | } | |
502 | ||
503 | /* | |
504 | * determine whether a mapping should be permitted and, if so, what sort of | |
505 | * mapping we're capable of supporting | |
506 | */ | |
507 | static int validate_mmap_request(struct file *file, | |
508 | unsigned long addr, | |
509 | unsigned long len, | |
510 | unsigned long prot, | |
511 | unsigned long flags, | |
512 | unsigned long pgoff, | |
513 | unsigned long *_capabilities) | |
514 | { | |
515 | unsigned long capabilities; | |
516 | unsigned long reqprot = prot; | |
517 | int ret; | |
518 | ||
519 | /* do the simple checks first */ | |
520 | if (flags & MAP_FIXED || addr) { | |
521 | printk(KERN_DEBUG | |
522 | "%d: Can't do fixed-address/overlay mmap of RAM\n", | |
523 | current->pid); | |
524 | return -EINVAL; | |
525 | } | |
526 | ||
527 | if ((flags & MAP_TYPE) != MAP_PRIVATE && | |
528 | (flags & MAP_TYPE) != MAP_SHARED) | |
529 | return -EINVAL; | |
530 | ||
f81cff0d | 531 | if (!len) |
1da177e4 LT |
532 | return -EINVAL; |
533 | ||
f81cff0d MF |
534 | /* Careful about overflows.. */ |
535 | len = PAGE_ALIGN(len); | |
536 | if (!len || len > TASK_SIZE) | |
537 | return -ENOMEM; | |
538 | ||
1da177e4 LT |
539 | /* offset overflow? */ |
540 | if ((pgoff + (len >> PAGE_SHIFT)) < pgoff) | |
f81cff0d | 541 | return -EOVERFLOW; |
1da177e4 LT |
542 | |
543 | if (file) { | |
544 | /* validate file mapping requests */ | |
545 | struct address_space *mapping; | |
546 | ||
547 | /* files must support mmap */ | |
548 | if (!file->f_op || !file->f_op->mmap) | |
549 | return -ENODEV; | |
550 | ||
551 | /* work out if what we've got could possibly be shared | |
552 | * - we support chardevs that provide their own "memory" | |
553 | * - we support files/blockdevs that are memory backed | |
554 | */ | |
555 | mapping = file->f_mapping; | |
556 | if (!mapping) | |
e9536ae7 | 557 | mapping = file->f_path.dentry->d_inode->i_mapping; |
1da177e4 LT |
558 | |
559 | capabilities = 0; | |
560 | if (mapping && mapping->backing_dev_info) | |
561 | capabilities = mapping->backing_dev_info->capabilities; | |
562 | ||
563 | if (!capabilities) { | |
564 | /* no explicit capabilities set, so assume some | |
565 | * defaults */ | |
e9536ae7 | 566 | switch (file->f_path.dentry->d_inode->i_mode & S_IFMT) { |
1da177e4 LT |
567 | case S_IFREG: |
568 | case S_IFBLK: | |
569 | capabilities = BDI_CAP_MAP_COPY; | |
570 | break; | |
571 | ||
572 | case S_IFCHR: | |
573 | capabilities = | |
574 | BDI_CAP_MAP_DIRECT | | |
575 | BDI_CAP_READ_MAP | | |
576 | BDI_CAP_WRITE_MAP; | |
577 | break; | |
578 | ||
579 | default: | |
580 | return -EINVAL; | |
581 | } | |
582 | } | |
583 | ||
584 | /* eliminate any capabilities that we can't support on this | |
585 | * device */ | |
586 | if (!file->f_op->get_unmapped_area) | |
587 | capabilities &= ~BDI_CAP_MAP_DIRECT; | |
588 | if (!file->f_op->read) | |
589 | capabilities &= ~BDI_CAP_MAP_COPY; | |
590 | ||
591 | if (flags & MAP_SHARED) { | |
592 | /* do checks for writing, appending and locking */ | |
593 | if ((prot & PROT_WRITE) && | |
594 | !(file->f_mode & FMODE_WRITE)) | |
595 | return -EACCES; | |
596 | ||
e9536ae7 | 597 | if (IS_APPEND(file->f_path.dentry->d_inode) && |
1da177e4 LT |
598 | (file->f_mode & FMODE_WRITE)) |
599 | return -EACCES; | |
600 | ||
e9536ae7 | 601 | if (locks_verify_locked(file->f_path.dentry->d_inode)) |
1da177e4 LT |
602 | return -EAGAIN; |
603 | ||
604 | if (!(capabilities & BDI_CAP_MAP_DIRECT)) | |
605 | return -ENODEV; | |
606 | ||
607 | if (((prot & PROT_READ) && !(capabilities & BDI_CAP_READ_MAP)) || | |
608 | ((prot & PROT_WRITE) && !(capabilities & BDI_CAP_WRITE_MAP)) || | |
609 | ((prot & PROT_EXEC) && !(capabilities & BDI_CAP_EXEC_MAP)) | |
610 | ) { | |
611 | printk("MAP_SHARED not completely supported on !MMU\n"); | |
612 | return -EINVAL; | |
613 | } | |
614 | ||
615 | /* we mustn't privatise shared mappings */ | |
616 | capabilities &= ~BDI_CAP_MAP_COPY; | |
617 | } | |
618 | else { | |
619 | /* we're going to read the file into private memory we | |
620 | * allocate */ | |
621 | if (!(capabilities & BDI_CAP_MAP_COPY)) | |
622 | return -ENODEV; | |
623 | ||
624 | /* we don't permit a private writable mapping to be | |
625 | * shared with the backing device */ | |
626 | if (prot & PROT_WRITE) | |
627 | capabilities &= ~BDI_CAP_MAP_DIRECT; | |
628 | } | |
629 | ||
630 | /* handle executable mappings and implied executable | |
631 | * mappings */ | |
e9536ae7 | 632 | if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) { |
1da177e4 LT |
633 | if (prot & PROT_EXEC) |
634 | return -EPERM; | |
635 | } | |
636 | else if ((prot & PROT_READ) && !(prot & PROT_EXEC)) { | |
637 | /* handle implication of PROT_EXEC by PROT_READ */ | |
638 | if (current->personality & READ_IMPLIES_EXEC) { | |
639 | if (capabilities & BDI_CAP_EXEC_MAP) | |
640 | prot |= PROT_EXEC; | |
641 | } | |
642 | } | |
643 | else if ((prot & PROT_READ) && | |
644 | (prot & PROT_EXEC) && | |
645 | !(capabilities & BDI_CAP_EXEC_MAP) | |
646 | ) { | |
647 | /* backing file is not executable, try to copy */ | |
648 | capabilities &= ~BDI_CAP_MAP_DIRECT; | |
649 | } | |
650 | } | |
651 | else { | |
652 | /* anonymous mappings are always memory backed and can be | |
653 | * privately mapped | |
654 | */ | |
655 | capabilities = BDI_CAP_MAP_COPY; | |
656 | ||
657 | /* handle PROT_EXEC implication by PROT_READ */ | |
658 | if ((prot & PROT_READ) && | |
659 | (current->personality & READ_IMPLIES_EXEC)) | |
660 | prot |= PROT_EXEC; | |
661 | } | |
662 | ||
663 | /* allow the security API to have its say */ | |
ed032189 | 664 | ret = security_file_mmap(file, reqprot, prot, flags, addr, 0); |
1da177e4 LT |
665 | if (ret < 0) |
666 | return ret; | |
667 | ||
668 | /* looks okay */ | |
669 | *_capabilities = capabilities; | |
670 | return 0; | |
671 | } | |
672 | ||
673 | /* | |
674 | * we've determined that we can make the mapping, now translate what we | |
675 | * now know into VMA flags | |
676 | */ | |
677 | static unsigned long determine_vm_flags(struct file *file, | |
678 | unsigned long prot, | |
679 | unsigned long flags, | |
680 | unsigned long capabilities) | |
681 | { | |
682 | unsigned long vm_flags; | |
683 | ||
684 | vm_flags = calc_vm_prot_bits(prot) | calc_vm_flag_bits(flags); | |
685 | vm_flags |= VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC; | |
686 | /* vm_flags |= mm->def_flags; */ | |
687 | ||
688 | if (!(capabilities & BDI_CAP_MAP_DIRECT)) { | |
689 | /* attempt to share read-only copies of mapped file chunks */ | |
690 | if (file && !(prot & PROT_WRITE)) | |
691 | vm_flags |= VM_MAYSHARE; | |
692 | } | |
693 | else { | |
694 | /* overlay a shareable mapping on the backing device or inode | |
695 | * if possible - used for chardevs, ramfs/tmpfs/shmfs and | |
696 | * romfs/cramfs */ | |
697 | if (flags & MAP_SHARED) | |
698 | vm_flags |= VM_MAYSHARE | VM_SHARED; | |
699 | else if ((((vm_flags & capabilities) ^ vm_flags) & BDI_CAP_VMFLAGS) == 0) | |
700 | vm_flags |= VM_MAYSHARE; | |
701 | } | |
702 | ||
703 | /* refuse to let anyone share private mappings with this process if | |
704 | * it's being traced - otherwise breakpoints set in it may interfere | |
705 | * with another untraced process | |
706 | */ | |
707 | if ((flags & MAP_PRIVATE) && (current->ptrace & PT_PTRACED)) | |
708 | vm_flags &= ~VM_MAYSHARE; | |
709 | ||
710 | return vm_flags; | |
711 | } | |
712 | ||
713 | /* | |
714 | * set up a shared mapping on a file | |
715 | */ | |
716 | static int do_mmap_shared_file(struct vm_area_struct *vma, unsigned long len) | |
717 | { | |
718 | int ret; | |
719 | ||
720 | ret = vma->vm_file->f_op->mmap(vma->vm_file, vma); | |
721 | if (ret != -ENOSYS) | |
722 | return ret; | |
723 | ||
724 | /* getting an ENOSYS error indicates that direct mmap isn't | |
725 | * possible (as opposed to tried but failed) so we'll fall | |
726 | * through to making a private copy of the data and mapping | |
727 | * that if we can */ | |
728 | return -ENODEV; | |
729 | } | |
730 | ||
731 | /* | |
732 | * set up a private mapping or an anonymous shared mapping | |
733 | */ | |
734 | static int do_mmap_private(struct vm_area_struct *vma, unsigned long len) | |
735 | { | |
736 | void *base; | |
737 | int ret; | |
738 | ||
739 | /* invoke the file's mapping function so that it can keep track of | |
740 | * shared mappings on devices or memory | |
741 | * - VM_MAYSHARE will be set if it may attempt to share | |
742 | */ | |
743 | if (vma->vm_file) { | |
744 | ret = vma->vm_file->f_op->mmap(vma->vm_file, vma); | |
745 | if (ret != -ENOSYS) { | |
746 | /* shouldn't return success if we're not sharing */ | |
747 | BUG_ON(ret == 0 && !(vma->vm_flags & VM_MAYSHARE)); | |
748 | return ret; /* success or a real error */ | |
749 | } | |
750 | ||
751 | /* getting an ENOSYS error indicates that direct mmap isn't | |
752 | * possible (as opposed to tried but failed) so we'll try to | |
753 | * make a private copy of the data and map that instead */ | |
754 | } | |
755 | ||
756 | /* allocate some memory to hold the mapping | |
757 | * - note that this may not return a page-aligned address if the object | |
758 | * we're allocating is smaller than a page | |
759 | */ | |
84097518 | 760 | base = kmalloc(len, GFP_KERNEL|__GFP_COMP); |
1da177e4 LT |
761 | if (!base) |
762 | goto enomem; | |
763 | ||
764 | vma->vm_start = (unsigned long) base; | |
765 | vma->vm_end = vma->vm_start + len; | |
766 | vma->vm_flags |= VM_MAPPED_COPY; | |
767 | ||
768 | #ifdef WARN_ON_SLACK | |
769 | if (len + WARN_ON_SLACK <= kobjsize(result)) | |
770 | printk("Allocation of %lu bytes from process %d has %lu bytes of slack\n", | |
771 | len, current->pid, kobjsize(result) - len); | |
772 | #endif | |
773 | ||
774 | if (vma->vm_file) { | |
775 | /* read the contents of a file into the copy */ | |
776 | mm_segment_t old_fs; | |
777 | loff_t fpos; | |
778 | ||
779 | fpos = vma->vm_pgoff; | |
780 | fpos <<= PAGE_SHIFT; | |
781 | ||
782 | old_fs = get_fs(); | |
783 | set_fs(KERNEL_DS); | |
784 | ret = vma->vm_file->f_op->read(vma->vm_file, base, len, &fpos); | |
785 | set_fs(old_fs); | |
786 | ||
787 | if (ret < 0) | |
788 | goto error_free; | |
789 | ||
790 | /* clear the last little bit */ | |
791 | if (ret < len) | |
792 | memset(base + ret, 0, len - ret); | |
793 | ||
794 | } else { | |
795 | /* if it's an anonymous mapping, then just clear it */ | |
796 | memset(base, 0, len); | |
797 | } | |
798 | ||
799 | return 0; | |
800 | ||
801 | error_free: | |
802 | kfree(base); | |
803 | vma->vm_start = 0; | |
804 | return ret; | |
805 | ||
806 | enomem: | |
807 | printk("Allocation of length %lu from process %d failed\n", | |
808 | len, current->pid); | |
809 | show_free_areas(); | |
810 | return -ENOMEM; | |
811 | } | |
812 | ||
813 | /* | |
814 | * handle mapping creation for uClinux | |
815 | */ | |
816 | unsigned long do_mmap_pgoff(struct file *file, | |
817 | unsigned long addr, | |
818 | unsigned long len, | |
819 | unsigned long prot, | |
820 | unsigned long flags, | |
821 | unsigned long pgoff) | |
822 | { | |
823 | struct vm_list_struct *vml = NULL; | |
824 | struct vm_area_struct *vma = NULL; | |
825 | struct rb_node *rb; | |
826 | unsigned long capabilities, vm_flags; | |
827 | void *result; | |
828 | int ret; | |
829 | ||
830 | /* decide whether we should attempt the mapping, and if so what sort of | |
831 | * mapping */ | |
832 | ret = validate_mmap_request(file, addr, len, prot, flags, pgoff, | |
833 | &capabilities); | |
834 | if (ret < 0) | |
835 | return ret; | |
836 | ||
837 | /* we've determined that we can make the mapping, now translate what we | |
838 | * now know into VMA flags */ | |
839 | vm_flags = determine_vm_flags(file, prot, flags, capabilities); | |
840 | ||
841 | /* we're going to need to record the mapping if it works */ | |
4668edc3 | 842 | vml = kzalloc(sizeof(struct vm_list_struct), GFP_KERNEL); |
1da177e4 LT |
843 | if (!vml) |
844 | goto error_getting_vml; | |
1da177e4 LT |
845 | |
846 | down_write(&nommu_vma_sem); | |
847 | ||
848 | /* if we want to share, we need to check for VMAs created by other | |
849 | * mmap() calls that overlap with our proposed mapping | |
850 | * - we can only share with an exact match on most regular files | |
851 | * - shared mappings on character devices and memory backed files are | |
852 | * permitted to overlap inexactly as far as we are concerned for in | |
853 | * these cases, sharing is handled in the driver or filesystem rather | |
854 | * than here | |
855 | */ | |
856 | if (vm_flags & VM_MAYSHARE) { | |
857 | unsigned long pglen = (len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
858 | unsigned long vmpglen; | |
859 | ||
165b2392 DH |
860 | /* suppress VMA sharing for shared regions */ |
861 | if (vm_flags & VM_SHARED && | |
862 | capabilities & BDI_CAP_MAP_DIRECT) | |
863 | goto dont_share_VMAs; | |
864 | ||
1da177e4 LT |
865 | for (rb = rb_first(&nommu_vma_tree); rb; rb = rb_next(rb)) { |
866 | vma = rb_entry(rb, struct vm_area_struct, vm_rb); | |
867 | ||
868 | if (!(vma->vm_flags & VM_MAYSHARE)) | |
869 | continue; | |
870 | ||
871 | /* search for overlapping mappings on the same file */ | |
e9536ae7 | 872 | if (vma->vm_file->f_path.dentry->d_inode != file->f_path.dentry->d_inode) |
1da177e4 LT |
873 | continue; |
874 | ||
875 | if (vma->vm_pgoff >= pgoff + pglen) | |
876 | continue; | |
877 | ||
878 | vmpglen = vma->vm_end - vma->vm_start + PAGE_SIZE - 1; | |
879 | vmpglen >>= PAGE_SHIFT; | |
880 | if (pgoff >= vma->vm_pgoff + vmpglen) | |
881 | continue; | |
882 | ||
883 | /* handle inexactly overlapping matches between mappings */ | |
884 | if (vma->vm_pgoff != pgoff || vmpglen != pglen) { | |
885 | if (!(capabilities & BDI_CAP_MAP_DIRECT)) | |
886 | goto sharing_violation; | |
887 | continue; | |
888 | } | |
889 | ||
890 | /* we've found a VMA we can share */ | |
891 | atomic_inc(&vma->vm_usage); | |
892 | ||
893 | vml->vma = vma; | |
894 | result = (void *) vma->vm_start; | |
895 | goto shared; | |
896 | } | |
897 | ||
165b2392 | 898 | dont_share_VMAs: |
1da177e4 LT |
899 | vma = NULL; |
900 | ||
901 | /* obtain the address at which to make a shared mapping | |
902 | * - this is the hook for quasi-memory character devices to | |
903 | * tell us the location of a shared mapping | |
904 | */ | |
905 | if (file && file->f_op->get_unmapped_area) { | |
906 | addr = file->f_op->get_unmapped_area(file, addr, len, | |
907 | pgoff, flags); | |
908 | if (IS_ERR((void *) addr)) { | |
909 | ret = addr; | |
910 | if (ret != (unsigned long) -ENOSYS) | |
911 | goto error; | |
912 | ||
913 | /* the driver refused to tell us where to site | |
914 | * the mapping so we'll have to attempt to copy | |
915 | * it */ | |
916 | ret = (unsigned long) -ENODEV; | |
917 | if (!(capabilities & BDI_CAP_MAP_COPY)) | |
918 | goto error; | |
919 | ||
920 | capabilities &= ~BDI_CAP_MAP_DIRECT; | |
921 | } | |
922 | } | |
923 | } | |
924 | ||
925 | /* we're going to need a VMA struct as well */ | |
4668edc3 | 926 | vma = kzalloc(sizeof(struct vm_area_struct), GFP_KERNEL); |
1da177e4 LT |
927 | if (!vma) |
928 | goto error_getting_vma; | |
929 | ||
1da177e4 LT |
930 | INIT_LIST_HEAD(&vma->anon_vma_node); |
931 | atomic_set(&vma->vm_usage, 1); | |
932 | if (file) | |
933 | get_file(file); | |
934 | vma->vm_file = file; | |
935 | vma->vm_flags = vm_flags; | |
936 | vma->vm_start = addr; | |
937 | vma->vm_end = addr + len; | |
938 | vma->vm_pgoff = pgoff; | |
939 | ||
940 | vml->vma = vma; | |
941 | ||
942 | /* set up the mapping */ | |
943 | if (file && vma->vm_flags & VM_SHARED) | |
944 | ret = do_mmap_shared_file(vma, len); | |
945 | else | |
946 | ret = do_mmap_private(vma, len); | |
947 | if (ret < 0) | |
948 | goto error; | |
949 | ||
950 | /* okay... we have a mapping; now we have to register it */ | |
951 | result = (void *) vma->vm_start; | |
952 | ||
953 | if (vma->vm_flags & VM_MAPPED_COPY) { | |
954 | realalloc += kobjsize(result); | |
955 | askedalloc += len; | |
956 | } | |
957 | ||
958 | realalloc += kobjsize(vma); | |
959 | askedalloc += sizeof(*vma); | |
960 | ||
961 | current->mm->total_vm += len >> PAGE_SHIFT; | |
962 | ||
963 | add_nommu_vma(vma); | |
964 | ||
965 | shared: | |
966 | realalloc += kobjsize(vml); | |
967 | askedalloc += sizeof(*vml); | |
968 | ||
3034097a | 969 | add_vma_to_mm(current->mm, vml); |
1da177e4 LT |
970 | |
971 | up_write(&nommu_vma_sem); | |
972 | ||
973 | if (prot & PROT_EXEC) | |
974 | flush_icache_range((unsigned long) result, | |
975 | (unsigned long) result + len); | |
976 | ||
977 | #ifdef DEBUG | |
978 | printk("do_mmap:\n"); | |
979 | show_process_blocks(); | |
980 | #endif | |
981 | ||
982 | return (unsigned long) result; | |
983 | ||
984 | error: | |
985 | up_write(&nommu_vma_sem); | |
986 | kfree(vml); | |
987 | if (vma) { | |
3fcd03e0 GL |
988 | if (vma->vm_file) |
989 | fput(vma->vm_file); | |
1da177e4 LT |
990 | kfree(vma); |
991 | } | |
992 | return ret; | |
993 | ||
994 | sharing_violation: | |
995 | up_write(&nommu_vma_sem); | |
996 | printk("Attempt to share mismatched mappings\n"); | |
997 | kfree(vml); | |
998 | return -EINVAL; | |
999 | ||
1000 | error_getting_vma: | |
1001 | up_write(&nommu_vma_sem); | |
1002 | kfree(vml); | |
66aa2b4b | 1003 | printk("Allocation of vma for %lu byte allocation from process %d failed\n", |
1da177e4 LT |
1004 | len, current->pid); |
1005 | show_free_areas(); | |
1006 | return -ENOMEM; | |
1007 | ||
1008 | error_getting_vml: | |
1009 | printk("Allocation of vml for %lu byte allocation from process %d failed\n", | |
1010 | len, current->pid); | |
1011 | show_free_areas(); | |
1012 | return -ENOMEM; | |
1013 | } | |
b5073173 | 1014 | EXPORT_SYMBOL(do_mmap_pgoff); |
1da177e4 LT |
1015 | |
1016 | /* | |
1017 | * handle mapping disposal for uClinux | |
1018 | */ | |
1019 | static void put_vma(struct vm_area_struct *vma) | |
1020 | { | |
1021 | if (vma) { | |
1022 | down_write(&nommu_vma_sem); | |
1023 | ||
1024 | if (atomic_dec_and_test(&vma->vm_usage)) { | |
1025 | delete_nommu_vma(vma); | |
1026 | ||
1027 | if (vma->vm_ops && vma->vm_ops->close) | |
1028 | vma->vm_ops->close(vma); | |
1029 | ||
1030 | /* IO memory and memory shared directly out of the pagecache from | |
1031 | * ramfs/tmpfs mustn't be released here */ | |
1032 | if (vma->vm_flags & VM_MAPPED_COPY) { | |
1033 | realalloc -= kobjsize((void *) vma->vm_start); | |
1034 | askedalloc -= vma->vm_end - vma->vm_start; | |
1035 | kfree((void *) vma->vm_start); | |
1036 | } | |
1037 | ||
1038 | realalloc -= kobjsize(vma); | |
1039 | askedalloc -= sizeof(*vma); | |
1040 | ||
1041 | if (vma->vm_file) | |
1042 | fput(vma->vm_file); | |
1043 | kfree(vma); | |
1044 | } | |
1045 | ||
1046 | up_write(&nommu_vma_sem); | |
1047 | } | |
1048 | } | |
1049 | ||
3034097a DH |
1050 | /* |
1051 | * release a mapping | |
1052 | * - under NOMMU conditions the parameters must match exactly to the mapping to | |
1053 | * be removed | |
1054 | */ | |
1da177e4 LT |
1055 | int do_munmap(struct mm_struct *mm, unsigned long addr, size_t len) |
1056 | { | |
1057 | struct vm_list_struct *vml, **parent; | |
1058 | unsigned long end = addr + len; | |
1059 | ||
1060 | #ifdef DEBUG | |
1061 | printk("do_munmap:\n"); | |
1062 | #endif | |
1063 | ||
3034097a DH |
1064 | for (parent = &mm->context.vmlist; *parent; parent = &(*parent)->next) { |
1065 | if ((*parent)->vma->vm_start > addr) | |
1066 | break; | |
1da177e4 | 1067 | if ((*parent)->vma->vm_start == addr && |
66aa2b4b | 1068 | ((len == 0) || ((*parent)->vma->vm_end == end))) |
1da177e4 | 1069 | goto found; |
3034097a | 1070 | } |
1da177e4 LT |
1071 | |
1072 | printk("munmap of non-mmaped memory by process %d (%s): %p\n", | |
1073 | current->pid, current->comm, (void *) addr); | |
1074 | return -EINVAL; | |
1075 | ||
1076 | found: | |
1077 | vml = *parent; | |
1078 | ||
1079 | put_vma(vml->vma); | |
1080 | ||
1081 | *parent = vml->next; | |
1082 | realalloc -= kobjsize(vml); | |
1083 | askedalloc -= sizeof(*vml); | |
1084 | kfree(vml); | |
365e9c87 HD |
1085 | |
1086 | update_hiwater_vm(mm); | |
1da177e4 LT |
1087 | mm->total_vm -= len >> PAGE_SHIFT; |
1088 | ||
1089 | #ifdef DEBUG | |
1090 | show_process_blocks(); | |
1091 | #endif | |
1092 | ||
1093 | return 0; | |
1094 | } | |
b5073173 | 1095 | EXPORT_SYMBOL(do_munmap); |
1da177e4 | 1096 | |
3034097a DH |
1097 | asmlinkage long sys_munmap(unsigned long addr, size_t len) |
1098 | { | |
1099 | int ret; | |
1100 | struct mm_struct *mm = current->mm; | |
1101 | ||
1102 | down_write(&mm->mmap_sem); | |
1103 | ret = do_munmap(mm, addr, len); | |
1104 | up_write(&mm->mmap_sem); | |
1105 | return ret; | |
1106 | } | |
1107 | ||
1108 | /* | |
1109 | * Release all mappings | |
1110 | */ | |
1da177e4 LT |
1111 | void exit_mmap(struct mm_struct * mm) |
1112 | { | |
1113 | struct vm_list_struct *tmp; | |
1114 | ||
1115 | if (mm) { | |
1116 | #ifdef DEBUG | |
1117 | printk("Exit_mmap:\n"); | |
1118 | #endif | |
1119 | ||
1120 | mm->total_vm = 0; | |
1121 | ||
1122 | while ((tmp = mm->context.vmlist)) { | |
1123 | mm->context.vmlist = tmp->next; | |
1124 | put_vma(tmp->vma); | |
1125 | ||
1126 | realalloc -= kobjsize(tmp); | |
1127 | askedalloc -= sizeof(*tmp); | |
1128 | kfree(tmp); | |
1129 | } | |
1130 | ||
1131 | #ifdef DEBUG | |
1132 | show_process_blocks(); | |
1133 | #endif | |
1134 | } | |
1135 | } | |
1136 | ||
1da177e4 LT |
1137 | unsigned long do_brk(unsigned long addr, unsigned long len) |
1138 | { | |
1139 | return -ENOMEM; | |
1140 | } | |
1141 | ||
1142 | /* | |
6fa5f80b DH |
1143 | * expand (or shrink) an existing mapping, potentially moving it at the same |
1144 | * time (controlled by the MREMAP_MAYMOVE flag and available VM space) | |
1da177e4 | 1145 | * |
6fa5f80b DH |
1146 | * under NOMMU conditions, we only permit changing a mapping's size, and only |
1147 | * as long as it stays within the hole allocated by the kmalloc() call in | |
1148 | * do_mmap_pgoff() and the block is not shareable | |
1da177e4 | 1149 | * |
6fa5f80b | 1150 | * MREMAP_FIXED is not supported under NOMMU conditions |
1da177e4 LT |
1151 | */ |
1152 | unsigned long do_mremap(unsigned long addr, | |
1153 | unsigned long old_len, unsigned long new_len, | |
1154 | unsigned long flags, unsigned long new_addr) | |
1155 | { | |
6fa5f80b | 1156 | struct vm_area_struct *vma; |
1da177e4 LT |
1157 | |
1158 | /* insanity checks first */ | |
1159 | if (new_len == 0) | |
1160 | return (unsigned long) -EINVAL; | |
1161 | ||
1162 | if (flags & MREMAP_FIXED && new_addr != addr) | |
1163 | return (unsigned long) -EINVAL; | |
1164 | ||
6fa5f80b DH |
1165 | vma = find_vma_exact(current->mm, addr); |
1166 | if (!vma) | |
1167 | return (unsigned long) -EINVAL; | |
1da177e4 | 1168 | |
6fa5f80b | 1169 | if (vma->vm_end != vma->vm_start + old_len) |
1da177e4 LT |
1170 | return (unsigned long) -EFAULT; |
1171 | ||
6fa5f80b | 1172 | if (vma->vm_flags & VM_MAYSHARE) |
1da177e4 LT |
1173 | return (unsigned long) -EPERM; |
1174 | ||
1175 | if (new_len > kobjsize((void *) addr)) | |
1176 | return (unsigned long) -ENOMEM; | |
1177 | ||
1178 | /* all checks complete - do it */ | |
6fa5f80b | 1179 | vma->vm_end = vma->vm_start + new_len; |
1da177e4 LT |
1180 | |
1181 | askedalloc -= old_len; | |
1182 | askedalloc += new_len; | |
1183 | ||
6fa5f80b DH |
1184 | return vma->vm_start; |
1185 | } | |
b5073173 | 1186 | EXPORT_SYMBOL(do_mremap); |
6fa5f80b DH |
1187 | |
1188 | asmlinkage unsigned long sys_mremap(unsigned long addr, | |
1189 | unsigned long old_len, unsigned long new_len, | |
1190 | unsigned long flags, unsigned long new_addr) | |
1191 | { | |
1192 | unsigned long ret; | |
1193 | ||
1194 | down_write(¤t->mm->mmap_sem); | |
1195 | ret = do_mremap(addr, old_len, new_len, flags, new_addr); | |
1196 | up_write(¤t->mm->mmap_sem); | |
1197 | return ret; | |
1da177e4 LT |
1198 | } |
1199 | ||
6aab341e | 1200 | struct page *follow_page(struct vm_area_struct *vma, unsigned long address, |
deceb6cd | 1201 | unsigned int foll_flags) |
1da177e4 LT |
1202 | { |
1203 | return NULL; | |
1204 | } | |
1205 | ||
1da177e4 LT |
1206 | int remap_pfn_range(struct vm_area_struct *vma, unsigned long from, |
1207 | unsigned long to, unsigned long size, pgprot_t prot) | |
1208 | { | |
66aa2b4b GU |
1209 | vma->vm_start = vma->vm_pgoff << PAGE_SHIFT; |
1210 | return 0; | |
1da177e4 | 1211 | } |
22c4af40 | 1212 | EXPORT_SYMBOL(remap_pfn_range); |
1da177e4 LT |
1213 | |
1214 | void swap_unplug_io_fn(struct backing_dev_info *bdi, struct page *page) | |
1215 | { | |
1216 | } | |
1217 | ||
1218 | unsigned long arch_get_unmapped_area(struct file *file, unsigned long addr, | |
1219 | unsigned long len, unsigned long pgoff, unsigned long flags) | |
1220 | { | |
1221 | return -ENOMEM; | |
1222 | } | |
1223 | ||
1363c3cd | 1224 | void arch_unmap_area(struct mm_struct *mm, unsigned long addr) |
1da177e4 LT |
1225 | { |
1226 | } | |
1227 | ||
1da177e4 LT |
1228 | void unmap_mapping_range(struct address_space *mapping, |
1229 | loff_t const holebegin, loff_t const holelen, | |
1230 | int even_cows) | |
1231 | { | |
1232 | } | |
22c4af40 | 1233 | EXPORT_SYMBOL(unmap_mapping_range); |
1da177e4 | 1234 | |
d56e03cd DH |
1235 | /* |
1236 | * ask for an unmapped area at which to create a mapping on a file | |
1237 | */ | |
1238 | unsigned long get_unmapped_area(struct file *file, unsigned long addr, | |
1239 | unsigned long len, unsigned long pgoff, | |
1240 | unsigned long flags) | |
1241 | { | |
1242 | unsigned long (*get_area)(struct file *, unsigned long, unsigned long, | |
1243 | unsigned long, unsigned long); | |
1244 | ||
1245 | get_area = current->mm->get_unmapped_area; | |
1246 | if (file && file->f_op && file->f_op->get_unmapped_area) | |
1247 | get_area = file->f_op->get_unmapped_area; | |
1248 | ||
1249 | if (!get_area) | |
1250 | return -ENOSYS; | |
1251 | ||
1252 | return get_area(file, addr, len, pgoff, flags); | |
1253 | } | |
d56e03cd DH |
1254 | EXPORT_SYMBOL(get_unmapped_area); |
1255 | ||
1da177e4 LT |
1256 | /* |
1257 | * Check that a process has enough memory to allocate a new virtual | |
1258 | * mapping. 0 means there is enough memory for the allocation to | |
1259 | * succeed and -ENOMEM implies there is not. | |
1260 | * | |
1261 | * We currently support three overcommit policies, which are set via the | |
1262 | * vm.overcommit_memory sysctl. See Documentation/vm/overcommit-accounting | |
1263 | * | |
1264 | * Strict overcommit modes added 2002 Feb 26 by Alan Cox. | |
1265 | * Additional code 2002 Jul 20 by Robert Love. | |
1266 | * | |
1267 | * cap_sys_admin is 1 if the process has admin privileges, 0 otherwise. | |
1268 | * | |
1269 | * Note this is a helper function intended to be used by LSMs which | |
1270 | * wish to use this logic. | |
1271 | */ | |
34b4e4aa | 1272 | int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin) |
1da177e4 LT |
1273 | { |
1274 | unsigned long free, allowed; | |
1275 | ||
1276 | vm_acct_memory(pages); | |
1277 | ||
1278 | /* | |
1279 | * Sometimes we want to use more memory than we have | |
1280 | */ | |
1281 | if (sysctl_overcommit_memory == OVERCOMMIT_ALWAYS) | |
1282 | return 0; | |
1283 | ||
1284 | if (sysctl_overcommit_memory == OVERCOMMIT_GUESS) { | |
1285 | unsigned long n; | |
1286 | ||
347ce434 | 1287 | free = global_page_state(NR_FILE_PAGES); |
1da177e4 LT |
1288 | free += nr_swap_pages; |
1289 | ||
1290 | /* | |
1291 | * Any slabs which are created with the | |
1292 | * SLAB_RECLAIM_ACCOUNT flag claim to have contents | |
1293 | * which are reclaimable, under pressure. The dentry | |
1294 | * cache and most inode caches should fall into this | |
1295 | */ | |
972d1a7b | 1296 | free += global_page_state(NR_SLAB_RECLAIMABLE); |
1da177e4 LT |
1297 | |
1298 | /* | |
1299 | * Leave the last 3% for root | |
1300 | */ | |
1301 | if (!cap_sys_admin) | |
1302 | free -= free / 32; | |
1303 | ||
1304 | if (free > pages) | |
1305 | return 0; | |
1306 | ||
1307 | /* | |
1308 | * nr_free_pages() is very expensive on large systems, | |
1309 | * only call if we're about to fail. | |
1310 | */ | |
1311 | n = nr_free_pages(); | |
d5ddc79b HA |
1312 | |
1313 | /* | |
1314 | * Leave reserved pages. The pages are not for anonymous pages. | |
1315 | */ | |
1316 | if (n <= totalreserve_pages) | |
1317 | goto error; | |
1318 | else | |
1319 | n -= totalreserve_pages; | |
1320 | ||
1321 | /* | |
1322 | * Leave the last 3% for root | |
1323 | */ | |
1da177e4 LT |
1324 | if (!cap_sys_admin) |
1325 | n -= n / 32; | |
1326 | free += n; | |
1327 | ||
1328 | if (free > pages) | |
1329 | return 0; | |
d5ddc79b HA |
1330 | |
1331 | goto error; | |
1da177e4 LT |
1332 | } |
1333 | ||
1334 | allowed = totalram_pages * sysctl_overcommit_ratio / 100; | |
1335 | /* | |
1336 | * Leave the last 3% for root | |
1337 | */ | |
1338 | if (!cap_sys_admin) | |
1339 | allowed -= allowed / 32; | |
1340 | allowed += total_swap_pages; | |
1341 | ||
1342 | /* Don't let a single process grow too big: | |
1343 | leave 3% of the size of this process for other processes */ | |
1344 | allowed -= current->mm->total_vm / 32; | |
1345 | ||
2f60f8d3 SD |
1346 | /* |
1347 | * cast `allowed' as a signed long because vm_committed_space | |
1348 | * sometimes has a negative value | |
1349 | */ | |
1350 | if (atomic_read(&vm_committed_space) < (long)allowed) | |
1da177e4 | 1351 | return 0; |
d5ddc79b | 1352 | error: |
1da177e4 LT |
1353 | vm_unacct_memory(pages); |
1354 | ||
1355 | return -ENOMEM; | |
1356 | } | |
1357 | ||
1358 | int in_gate_area_no_task(unsigned long addr) | |
1359 | { | |
1360 | return 0; | |
1361 | } | |
b0e15190 | 1362 | |
d0217ac0 | 1363 | int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
b0e15190 DH |
1364 | { |
1365 | BUG(); | |
d0217ac0 | 1366 | return 0; |
b0e15190 | 1367 | } |
b5073173 | 1368 | EXPORT_SYMBOL(filemap_fault); |
0ec76a11 DH |
1369 | |
1370 | /* | |
1371 | * Access another process' address space. | |
1372 | * - source/target buffer must be kernel space | |
1373 | */ | |
1374 | int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write) | |
1375 | { | |
0ec76a11 DH |
1376 | struct vm_area_struct *vma; |
1377 | struct mm_struct *mm; | |
1378 | ||
1379 | if (addr + len < addr) | |
1380 | return 0; | |
1381 | ||
1382 | mm = get_task_mm(tsk); | |
1383 | if (!mm) | |
1384 | return 0; | |
1385 | ||
1386 | down_read(&mm->mmap_sem); | |
1387 | ||
1388 | /* the access must start within one of the target process's mappings */ | |
0159b141 DH |
1389 | vma = find_vma(mm, addr); |
1390 | if (vma) { | |
0ec76a11 DH |
1391 | /* don't overrun this mapping */ |
1392 | if (addr + len >= vma->vm_end) | |
1393 | len = vma->vm_end - addr; | |
1394 | ||
1395 | /* only read or write mappings where it is permitted */ | |
d00c7b99 | 1396 | if (write && vma->vm_flags & VM_MAYWRITE) |
0ec76a11 | 1397 | len -= copy_to_user((void *) addr, buf, len); |
d00c7b99 | 1398 | else if (!write && vma->vm_flags & VM_MAYREAD) |
0ec76a11 DH |
1399 | len -= copy_from_user(buf, (void *) addr, len); |
1400 | else | |
1401 | len = 0; | |
1402 | } else { | |
1403 | len = 0; | |
1404 | } | |
1405 | ||
1406 | up_read(&mm->mmap_sem); | |
1407 | mmput(mm); | |
1408 | return len; | |
1409 | } |