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Commit | Line | Data |
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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> | |
f905bc44 | 13 | * Copyright (c) 2007 Paul Mundt <lethal@linux-sh.org> |
1da177e4 LT |
14 | */ |
15 | ||
f2b8544f | 16 | #include <linux/module.h> |
1da177e4 LT |
17 | #include <linux/mm.h> |
18 | #include <linux/mman.h> | |
19 | #include <linux/swap.h> | |
20 | #include <linux/file.h> | |
21 | #include <linux/highmem.h> | |
22 | #include <linux/pagemap.h> | |
23 | #include <linux/slab.h> | |
24 | #include <linux/vmalloc.h> | |
25 | #include <linux/ptrace.h> | |
26 | #include <linux/blkdev.h> | |
27 | #include <linux/backing-dev.h> | |
28 | #include <linux/mount.h> | |
29 | #include <linux/personality.h> | |
30 | #include <linux/security.h> | |
31 | #include <linux/syscalls.h> | |
32 | ||
33 | #include <asm/uaccess.h> | |
34 | #include <asm/tlb.h> | |
35 | #include <asm/tlbflush.h> | |
36 | ||
37 | void *high_memory; | |
38 | struct page *mem_map; | |
39 | unsigned long max_mapnr; | |
40 | unsigned long num_physpages; | |
41 | unsigned long askedalloc, realalloc; | |
80119ef5 | 42 | atomic_long_t vm_committed_space = ATOMIC_LONG_INIT(0); |
1da177e4 LT |
43 | int sysctl_overcommit_memory = OVERCOMMIT_GUESS; /* heuristic overcommit */ |
44 | int sysctl_overcommit_ratio = 50; /* default is 50% */ | |
45 | int sysctl_max_map_count = DEFAULT_MAX_MAP_COUNT; | |
46 | int heap_stack_gap = 0; | |
47 | ||
48 | EXPORT_SYMBOL(mem_map); | |
6a04de6d | 49 | EXPORT_SYMBOL(num_physpages); |
1da177e4 LT |
50 | |
51 | /* list of shareable VMAs */ | |
52 | struct rb_root nommu_vma_tree = RB_ROOT; | |
53 | DECLARE_RWSEM(nommu_vma_sem); | |
54 | ||
55 | struct vm_operations_struct generic_file_vm_ops = { | |
56 | }; | |
57 | ||
58 | /* | |
59 | * Handle all mappings that got truncated by a "truncate()" | |
60 | * system call. | |
61 | * | |
62 | * NOTE! We have to be ready to update the memory sharing | |
63 | * between the file and the memory map for a potential last | |
64 | * incomplete page. Ugly, but necessary. | |
65 | */ | |
66 | int vmtruncate(struct inode *inode, loff_t offset) | |
67 | { | |
68 | struct address_space *mapping = inode->i_mapping; | |
69 | unsigned long limit; | |
70 | ||
71 | if (inode->i_size < offset) | |
72 | goto do_expand; | |
73 | i_size_write(inode, offset); | |
74 | ||
75 | truncate_inode_pages(mapping, offset); | |
76 | goto out_truncate; | |
77 | ||
78 | do_expand: | |
79 | limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur; | |
80 | if (limit != RLIM_INFINITY && offset > limit) | |
81 | goto out_sig; | |
82 | if (offset > inode->i_sb->s_maxbytes) | |
83 | goto out; | |
84 | i_size_write(inode, offset); | |
85 | ||
86 | out_truncate: | |
87 | if (inode->i_op && inode->i_op->truncate) | |
88 | inode->i_op->truncate(inode); | |
89 | return 0; | |
90 | out_sig: | |
91 | send_sig(SIGXFSZ, current, 0); | |
92 | out: | |
93 | return -EFBIG; | |
94 | } | |
95 | ||
96 | EXPORT_SYMBOL(vmtruncate); | |
97 | ||
98 | /* | |
99 | * Return the total memory allocated for this pointer, not | |
100 | * just what the caller asked for. | |
101 | * | |
102 | * Doesn't have to be accurate, i.e. may have races. | |
103 | */ | |
104 | unsigned int kobjsize(const void *objp) | |
105 | { | |
106 | struct page *page; | |
6cfd53fc | 107 | int order = 0; |
1da177e4 | 108 | |
4016a139 MH |
109 | /* |
110 | * If the object we have should not have ksize performed on it, | |
111 | * return size of 0 | |
112 | */ | |
6cfd53fc | 113 | if (!objp) |
1da177e4 LT |
114 | return 0; |
115 | ||
6cfd53fc PM |
116 | if ((unsigned long)objp >= memory_end) |
117 | return 0; | |
118 | ||
119 | page = virt_to_head_page(objp); | |
120 | if (!page) | |
121 | return 0; | |
122 | ||
123 | /* | |
124 | * If the allocator sets PageSlab, we know the pointer came from | |
125 | * kmalloc(). | |
126 | */ | |
1da177e4 LT |
127 | if (PageSlab(page)) |
128 | return ksize(objp); | |
129 | ||
6cfd53fc PM |
130 | /* |
131 | * The ksize() function is only guaranteed to work for pointers | |
132 | * returned by kmalloc(). So handle arbitrary pointers, that we expect | |
133 | * always to be compound pages, here. | |
134 | */ | |
135 | if (PageCompound(page)) | |
136 | order = compound_order(page); | |
1da177e4 | 137 | |
6cfd53fc PM |
138 | /* |
139 | * Finally, handle arbitrary pointers that don't set PageSlab. | |
140 | * Default to 0-order in the case when we're unable to ksize() | |
141 | * the object. | |
142 | */ | |
143 | return PAGE_SIZE << order; | |
1da177e4 LT |
144 | } |
145 | ||
146 | /* | |
7b4d5b8b DH |
147 | * get a list of pages in an address range belonging to the specified process |
148 | * and indicate the VMA that covers each page | |
149 | * - this is potentially dodgy as we may end incrementing the page count of a | |
150 | * slab page or a secondary page from a compound page | |
151 | * - don't permit access to VMAs that don't support it, such as I/O mappings | |
1da177e4 LT |
152 | */ |
153 | int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, | |
154 | unsigned long start, int len, int write, int force, | |
155 | struct page **pages, struct vm_area_struct **vmas) | |
156 | { | |
910e46da | 157 | struct vm_area_struct *vma; |
7b4d5b8b DH |
158 | unsigned long vm_flags; |
159 | int i; | |
160 | ||
161 | /* calculate required read or write permissions. | |
162 | * - if 'force' is set, we only require the "MAY" flags. | |
163 | */ | |
164 | vm_flags = write ? (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD); | |
165 | vm_flags &= force ? (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE); | |
1da177e4 LT |
166 | |
167 | for (i = 0; i < len; i++) { | |
910e46da | 168 | vma = find_vma(mm, start); |
7b4d5b8b DH |
169 | if (!vma) |
170 | goto finish_or_fault; | |
171 | ||
172 | /* protect what we can, including chardevs */ | |
173 | if (vma->vm_flags & (VM_IO | VM_PFNMAP) || | |
174 | !(vm_flags & vma->vm_flags)) | |
175 | goto finish_or_fault; | |
910e46da | 176 | |
1da177e4 LT |
177 | if (pages) { |
178 | pages[i] = virt_to_page(start); | |
179 | if (pages[i]) | |
180 | page_cache_get(pages[i]); | |
181 | } | |
182 | if (vmas) | |
910e46da | 183 | vmas[i] = vma; |
1da177e4 LT |
184 | start += PAGE_SIZE; |
185 | } | |
7b4d5b8b DH |
186 | |
187 | return i; | |
188 | ||
189 | finish_or_fault: | |
190 | return i ? : -EFAULT; | |
1da177e4 | 191 | } |
66aa2b4b GU |
192 | EXPORT_SYMBOL(get_user_pages); |
193 | ||
1da177e4 LT |
194 | DEFINE_RWLOCK(vmlist_lock); |
195 | struct vm_struct *vmlist; | |
196 | ||
b3bdda02 | 197 | void vfree(const void *addr) |
1da177e4 LT |
198 | { |
199 | kfree(addr); | |
200 | } | |
b5073173 | 201 | EXPORT_SYMBOL(vfree); |
1da177e4 | 202 | |
dd0fc66f | 203 | void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot) |
1da177e4 LT |
204 | { |
205 | /* | |
8518609d RD |
206 | * You can't specify __GFP_HIGHMEM with kmalloc() since kmalloc() |
207 | * returns only a logical address. | |
1da177e4 | 208 | */ |
84097518 | 209 | return kmalloc(size, (gfp_mask | __GFP_COMP) & ~__GFP_HIGHMEM); |
1da177e4 | 210 | } |
b5073173 | 211 | EXPORT_SYMBOL(__vmalloc); |
1da177e4 | 212 | |
f905bc44 PM |
213 | void *vmalloc_user(unsigned long size) |
214 | { | |
215 | void *ret; | |
216 | ||
217 | ret = __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO, | |
218 | PAGE_KERNEL); | |
219 | if (ret) { | |
220 | struct vm_area_struct *vma; | |
221 | ||
222 | down_write(¤t->mm->mmap_sem); | |
223 | vma = find_vma(current->mm, (unsigned long)ret); | |
224 | if (vma) | |
225 | vma->vm_flags |= VM_USERMAP; | |
226 | up_write(¤t->mm->mmap_sem); | |
227 | } | |
228 | ||
229 | return ret; | |
230 | } | |
231 | EXPORT_SYMBOL(vmalloc_user); | |
232 | ||
b3bdda02 | 233 | struct page *vmalloc_to_page(const void *addr) |
1da177e4 LT |
234 | { |
235 | return virt_to_page(addr); | |
236 | } | |
b5073173 | 237 | EXPORT_SYMBOL(vmalloc_to_page); |
1da177e4 | 238 | |
b3bdda02 | 239 | unsigned long vmalloc_to_pfn(const void *addr) |
1da177e4 LT |
240 | { |
241 | return page_to_pfn(virt_to_page(addr)); | |
242 | } | |
b5073173 | 243 | EXPORT_SYMBOL(vmalloc_to_pfn); |
1da177e4 LT |
244 | |
245 | long vread(char *buf, char *addr, unsigned long count) | |
246 | { | |
247 | memcpy(buf, addr, count); | |
248 | return count; | |
249 | } | |
250 | ||
251 | long vwrite(char *buf, char *addr, unsigned long count) | |
252 | { | |
253 | /* Don't allow overflow */ | |
254 | if ((unsigned long) addr + count < count) | |
255 | count = -(unsigned long) addr; | |
256 | ||
257 | memcpy(addr, buf, count); | |
258 | return(count); | |
259 | } | |
260 | ||
261 | /* | |
262 | * vmalloc - allocate virtually continguos memory | |
263 | * | |
264 | * @size: allocation size | |
265 | * | |
266 | * Allocate enough pages to cover @size from the page level | |
267 | * allocator and map them into continguos kernel virtual space. | |
268 | * | |
c1c8897f | 269 | * For tight control over page level allocator and protection flags |
1da177e4 LT |
270 | * use __vmalloc() instead. |
271 | */ | |
272 | void *vmalloc(unsigned long size) | |
273 | { | |
274 | return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL); | |
275 | } | |
f6138882 AM |
276 | EXPORT_SYMBOL(vmalloc); |
277 | ||
278 | void *vmalloc_node(unsigned long size, int node) | |
279 | { | |
280 | return vmalloc(size); | |
281 | } | |
282 | EXPORT_SYMBOL(vmalloc_node); | |
1da177e4 | 283 | |
b5073173 PM |
284 | /** |
285 | * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) | |
1da177e4 LT |
286 | * @size: allocation size |
287 | * | |
288 | * Allocate enough 32bit PA addressable pages to cover @size from the | |
289 | * page level allocator and map them into continguos kernel virtual space. | |
290 | */ | |
291 | void *vmalloc_32(unsigned long size) | |
292 | { | |
293 | return __vmalloc(size, GFP_KERNEL, PAGE_KERNEL); | |
294 | } | |
b5073173 PM |
295 | EXPORT_SYMBOL(vmalloc_32); |
296 | ||
297 | /** | |
298 | * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory | |
299 | * @size: allocation size | |
300 | * | |
301 | * The resulting memory area is 32bit addressable and zeroed so it can be | |
302 | * mapped to userspace without leaking data. | |
f905bc44 PM |
303 | * |
304 | * VM_USERMAP is set on the corresponding VMA so that subsequent calls to | |
305 | * remap_vmalloc_range() are permissible. | |
b5073173 PM |
306 | */ |
307 | void *vmalloc_32_user(unsigned long size) | |
308 | { | |
f905bc44 PM |
309 | /* |
310 | * We'll have to sort out the ZONE_DMA bits for 64-bit, | |
311 | * but for now this can simply use vmalloc_user() directly. | |
312 | */ | |
313 | return vmalloc_user(size); | |
b5073173 PM |
314 | } |
315 | EXPORT_SYMBOL(vmalloc_32_user); | |
1da177e4 LT |
316 | |
317 | void *vmap(struct page **pages, unsigned int count, unsigned long flags, pgprot_t prot) | |
318 | { | |
319 | BUG(); | |
320 | return NULL; | |
321 | } | |
b5073173 | 322 | EXPORT_SYMBOL(vmap); |
1da177e4 | 323 | |
b3bdda02 | 324 | void vunmap(const void *addr) |
1da177e4 LT |
325 | { |
326 | BUG(); | |
327 | } | |
b5073173 | 328 | EXPORT_SYMBOL(vunmap); |
1da177e4 | 329 | |
1eeb66a1 CH |
330 | /* |
331 | * Implement a stub for vmalloc_sync_all() if the architecture chose not to | |
332 | * have one. | |
333 | */ | |
334 | void __attribute__((weak)) vmalloc_sync_all(void) | |
335 | { | |
336 | } | |
337 | ||
b5073173 PM |
338 | int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, |
339 | struct page *page) | |
340 | { | |
341 | return -EINVAL; | |
342 | } | |
343 | EXPORT_SYMBOL(vm_insert_page); | |
344 | ||
1da177e4 LT |
345 | /* |
346 | * sys_brk() for the most part doesn't need the global kernel | |
347 | * lock, except when an application is doing something nasty | |
348 | * like trying to un-brk an area that has already been mapped | |
349 | * to a regular file. in this case, the unmapping will need | |
350 | * to invoke file system routines that need the global lock. | |
351 | */ | |
352 | asmlinkage unsigned long sys_brk(unsigned long brk) | |
353 | { | |
354 | struct mm_struct *mm = current->mm; | |
355 | ||
356 | if (brk < mm->start_brk || brk > mm->context.end_brk) | |
357 | return mm->brk; | |
358 | ||
359 | if (mm->brk == brk) | |
360 | return mm->brk; | |
361 | ||
362 | /* | |
363 | * Always allow shrinking brk | |
364 | */ | |
365 | if (brk <= mm->brk) { | |
366 | mm->brk = brk; | |
367 | return brk; | |
368 | } | |
369 | ||
370 | /* | |
371 | * Ok, looks good - let it rip. | |
372 | */ | |
373 | return mm->brk = brk; | |
374 | } | |
375 | ||
376 | #ifdef DEBUG | |
377 | static void show_process_blocks(void) | |
378 | { | |
379 | struct vm_list_struct *vml; | |
380 | ||
381 | printk("Process blocks %d:", current->pid); | |
382 | ||
383 | for (vml = ¤t->mm->context.vmlist; vml; vml = vml->next) { | |
384 | printk(" %p: %p", vml, vml->vma); | |
385 | if (vml->vma) | |
386 | printk(" (%d @%lx #%d)", | |
387 | kobjsize((void *) vml->vma->vm_start), | |
388 | vml->vma->vm_start, | |
389 | atomic_read(&vml->vma->vm_usage)); | |
390 | printk(vml->next ? " ->" : ".\n"); | |
391 | } | |
392 | } | |
393 | #endif /* DEBUG */ | |
394 | ||
3034097a DH |
395 | /* |
396 | * add a VMA into a process's mm_struct in the appropriate place in the list | |
397 | * - should be called with mm->mmap_sem held writelocked | |
398 | */ | |
399 | static void add_vma_to_mm(struct mm_struct *mm, struct vm_list_struct *vml) | |
400 | { | |
401 | struct vm_list_struct **ppv; | |
402 | ||
403 | for (ppv = ¤t->mm->context.vmlist; *ppv; ppv = &(*ppv)->next) | |
404 | if ((*ppv)->vma->vm_start > vml->vma->vm_start) | |
405 | break; | |
406 | ||
407 | vml->next = *ppv; | |
408 | *ppv = vml; | |
409 | } | |
410 | ||
411 | /* | |
412 | * look up the first VMA in which addr resides, NULL if none | |
413 | * - should be called with mm->mmap_sem at least held readlocked | |
414 | */ | |
415 | struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) | |
416 | { | |
417 | struct vm_list_struct *loop, *vml; | |
418 | ||
419 | /* search the vm_start ordered list */ | |
420 | vml = NULL; | |
421 | for (loop = mm->context.vmlist; loop; loop = loop->next) { | |
422 | if (loop->vma->vm_start > addr) | |
423 | break; | |
424 | vml = loop; | |
425 | } | |
426 | ||
427 | if (vml && vml->vma->vm_end > addr) | |
428 | return vml->vma; | |
429 | ||
430 | return NULL; | |
431 | } | |
432 | EXPORT_SYMBOL(find_vma); | |
433 | ||
930e652a DH |
434 | /* |
435 | * find a VMA | |
436 | * - we don't extend stack VMAs under NOMMU conditions | |
437 | */ | |
438 | struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr) | |
439 | { | |
440 | return find_vma(mm, addr); | |
441 | } | |
442 | ||
57c8f63e GU |
443 | int expand_stack(struct vm_area_struct *vma, unsigned long address) |
444 | { | |
445 | return -ENOMEM; | |
446 | } | |
447 | ||
6fa5f80b DH |
448 | /* |
449 | * look up the first VMA exactly that exactly matches addr | |
450 | * - should be called with mm->mmap_sem at least held readlocked | |
451 | */ | |
452 | static inline struct vm_area_struct *find_vma_exact(struct mm_struct *mm, | |
453 | unsigned long addr) | |
454 | { | |
455 | struct vm_list_struct *vml; | |
456 | ||
457 | /* search the vm_start ordered list */ | |
458 | for (vml = mm->context.vmlist; vml; vml = vml->next) { | |
459 | if (vml->vma->vm_start == addr) | |
460 | return vml->vma; | |
461 | if (vml->vma->vm_start > addr) | |
462 | break; | |
463 | } | |
464 | ||
465 | return NULL; | |
466 | } | |
467 | ||
3034097a DH |
468 | /* |
469 | * find a VMA in the global tree | |
470 | */ | |
1da177e4 LT |
471 | static inline struct vm_area_struct *find_nommu_vma(unsigned long start) |
472 | { | |
473 | struct vm_area_struct *vma; | |
474 | struct rb_node *n = nommu_vma_tree.rb_node; | |
475 | ||
476 | while (n) { | |
477 | vma = rb_entry(n, struct vm_area_struct, vm_rb); | |
478 | ||
479 | if (start < vma->vm_start) | |
480 | n = n->rb_left; | |
481 | else if (start > vma->vm_start) | |
482 | n = n->rb_right; | |
483 | else | |
484 | return vma; | |
485 | } | |
486 | ||
487 | return NULL; | |
488 | } | |
489 | ||
3034097a DH |
490 | /* |
491 | * add a VMA in the global tree | |
492 | */ | |
1da177e4 LT |
493 | static void add_nommu_vma(struct vm_area_struct *vma) |
494 | { | |
495 | struct vm_area_struct *pvma; | |
496 | struct address_space *mapping; | |
497 | struct rb_node **p = &nommu_vma_tree.rb_node; | |
498 | struct rb_node *parent = NULL; | |
499 | ||
500 | /* add the VMA to the mapping */ | |
501 | if (vma->vm_file) { | |
502 | mapping = vma->vm_file->f_mapping; | |
503 | ||
504 | flush_dcache_mmap_lock(mapping); | |
505 | vma_prio_tree_insert(vma, &mapping->i_mmap); | |
506 | flush_dcache_mmap_unlock(mapping); | |
507 | } | |
508 | ||
509 | /* add the VMA to the master list */ | |
510 | while (*p) { | |
511 | parent = *p; | |
512 | pvma = rb_entry(parent, struct vm_area_struct, vm_rb); | |
513 | ||
514 | if (vma->vm_start < pvma->vm_start) { | |
515 | p = &(*p)->rb_left; | |
516 | } | |
517 | else if (vma->vm_start > pvma->vm_start) { | |
518 | p = &(*p)->rb_right; | |
519 | } | |
520 | else { | |
521 | /* mappings are at the same address - this can only | |
522 | * happen for shared-mem chardevs and shared file | |
523 | * mappings backed by ramfs/tmpfs */ | |
524 | BUG_ON(!(pvma->vm_flags & VM_SHARED)); | |
525 | ||
526 | if (vma < pvma) | |
527 | p = &(*p)->rb_left; | |
528 | else if (vma > pvma) | |
529 | p = &(*p)->rb_right; | |
530 | else | |
531 | BUG(); | |
532 | } | |
533 | } | |
534 | ||
535 | rb_link_node(&vma->vm_rb, parent, p); | |
536 | rb_insert_color(&vma->vm_rb, &nommu_vma_tree); | |
537 | } | |
538 | ||
3034097a DH |
539 | /* |
540 | * delete a VMA from the global list | |
541 | */ | |
1da177e4 LT |
542 | static void delete_nommu_vma(struct vm_area_struct *vma) |
543 | { | |
544 | struct address_space *mapping; | |
545 | ||
546 | /* remove the VMA from the mapping */ | |
547 | if (vma->vm_file) { | |
548 | mapping = vma->vm_file->f_mapping; | |
549 | ||
550 | flush_dcache_mmap_lock(mapping); | |
551 | vma_prio_tree_remove(vma, &mapping->i_mmap); | |
552 | flush_dcache_mmap_unlock(mapping); | |
553 | } | |
554 | ||
555 | /* remove from the master list */ | |
556 | rb_erase(&vma->vm_rb, &nommu_vma_tree); | |
557 | } | |
558 | ||
559 | /* | |
560 | * determine whether a mapping should be permitted and, if so, what sort of | |
561 | * mapping we're capable of supporting | |
562 | */ | |
563 | static int validate_mmap_request(struct file *file, | |
564 | unsigned long addr, | |
565 | unsigned long len, | |
566 | unsigned long prot, | |
567 | unsigned long flags, | |
568 | unsigned long pgoff, | |
569 | unsigned long *_capabilities) | |
570 | { | |
571 | unsigned long capabilities; | |
572 | unsigned long reqprot = prot; | |
573 | int ret; | |
574 | ||
575 | /* do the simple checks first */ | |
576 | if (flags & MAP_FIXED || addr) { | |
577 | printk(KERN_DEBUG | |
578 | "%d: Can't do fixed-address/overlay mmap of RAM\n", | |
579 | current->pid); | |
580 | return -EINVAL; | |
581 | } | |
582 | ||
583 | if ((flags & MAP_TYPE) != MAP_PRIVATE && | |
584 | (flags & MAP_TYPE) != MAP_SHARED) | |
585 | return -EINVAL; | |
586 | ||
f81cff0d | 587 | if (!len) |
1da177e4 LT |
588 | return -EINVAL; |
589 | ||
f81cff0d MF |
590 | /* Careful about overflows.. */ |
591 | len = PAGE_ALIGN(len); | |
592 | if (!len || len > TASK_SIZE) | |
593 | return -ENOMEM; | |
594 | ||
1da177e4 LT |
595 | /* offset overflow? */ |
596 | if ((pgoff + (len >> PAGE_SHIFT)) < pgoff) | |
f81cff0d | 597 | return -EOVERFLOW; |
1da177e4 LT |
598 | |
599 | if (file) { | |
600 | /* validate file mapping requests */ | |
601 | struct address_space *mapping; | |
602 | ||
603 | /* files must support mmap */ | |
604 | if (!file->f_op || !file->f_op->mmap) | |
605 | return -ENODEV; | |
606 | ||
607 | /* work out if what we've got could possibly be shared | |
608 | * - we support chardevs that provide their own "memory" | |
609 | * - we support files/blockdevs that are memory backed | |
610 | */ | |
611 | mapping = file->f_mapping; | |
612 | if (!mapping) | |
e9536ae7 | 613 | mapping = file->f_path.dentry->d_inode->i_mapping; |
1da177e4 LT |
614 | |
615 | capabilities = 0; | |
616 | if (mapping && mapping->backing_dev_info) | |
617 | capabilities = mapping->backing_dev_info->capabilities; | |
618 | ||
619 | if (!capabilities) { | |
620 | /* no explicit capabilities set, so assume some | |
621 | * defaults */ | |
e9536ae7 | 622 | switch (file->f_path.dentry->d_inode->i_mode & S_IFMT) { |
1da177e4 LT |
623 | case S_IFREG: |
624 | case S_IFBLK: | |
625 | capabilities = BDI_CAP_MAP_COPY; | |
626 | break; | |
627 | ||
628 | case S_IFCHR: | |
629 | capabilities = | |
630 | BDI_CAP_MAP_DIRECT | | |
631 | BDI_CAP_READ_MAP | | |
632 | BDI_CAP_WRITE_MAP; | |
633 | break; | |
634 | ||
635 | default: | |
636 | return -EINVAL; | |
637 | } | |
638 | } | |
639 | ||
640 | /* eliminate any capabilities that we can't support on this | |
641 | * device */ | |
642 | if (!file->f_op->get_unmapped_area) | |
643 | capabilities &= ~BDI_CAP_MAP_DIRECT; | |
644 | if (!file->f_op->read) | |
645 | capabilities &= ~BDI_CAP_MAP_COPY; | |
646 | ||
647 | if (flags & MAP_SHARED) { | |
648 | /* do checks for writing, appending and locking */ | |
649 | if ((prot & PROT_WRITE) && | |
650 | !(file->f_mode & FMODE_WRITE)) | |
651 | return -EACCES; | |
652 | ||
e9536ae7 | 653 | if (IS_APPEND(file->f_path.dentry->d_inode) && |
1da177e4 LT |
654 | (file->f_mode & FMODE_WRITE)) |
655 | return -EACCES; | |
656 | ||
e9536ae7 | 657 | if (locks_verify_locked(file->f_path.dentry->d_inode)) |
1da177e4 LT |
658 | return -EAGAIN; |
659 | ||
660 | if (!(capabilities & BDI_CAP_MAP_DIRECT)) | |
661 | return -ENODEV; | |
662 | ||
663 | if (((prot & PROT_READ) && !(capabilities & BDI_CAP_READ_MAP)) || | |
664 | ((prot & PROT_WRITE) && !(capabilities & BDI_CAP_WRITE_MAP)) || | |
665 | ((prot & PROT_EXEC) && !(capabilities & BDI_CAP_EXEC_MAP)) | |
666 | ) { | |
667 | printk("MAP_SHARED not completely supported on !MMU\n"); | |
668 | return -EINVAL; | |
669 | } | |
670 | ||
671 | /* we mustn't privatise shared mappings */ | |
672 | capabilities &= ~BDI_CAP_MAP_COPY; | |
673 | } | |
674 | else { | |
675 | /* we're going to read the file into private memory we | |
676 | * allocate */ | |
677 | if (!(capabilities & BDI_CAP_MAP_COPY)) | |
678 | return -ENODEV; | |
679 | ||
680 | /* we don't permit a private writable mapping to be | |
681 | * shared with the backing device */ | |
682 | if (prot & PROT_WRITE) | |
683 | capabilities &= ~BDI_CAP_MAP_DIRECT; | |
684 | } | |
685 | ||
686 | /* handle executable mappings and implied executable | |
687 | * mappings */ | |
e9536ae7 | 688 | if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) { |
1da177e4 LT |
689 | if (prot & PROT_EXEC) |
690 | return -EPERM; | |
691 | } | |
692 | else if ((prot & PROT_READ) && !(prot & PROT_EXEC)) { | |
693 | /* handle implication of PROT_EXEC by PROT_READ */ | |
694 | if (current->personality & READ_IMPLIES_EXEC) { | |
695 | if (capabilities & BDI_CAP_EXEC_MAP) | |
696 | prot |= PROT_EXEC; | |
697 | } | |
698 | } | |
699 | else if ((prot & PROT_READ) && | |
700 | (prot & PROT_EXEC) && | |
701 | !(capabilities & BDI_CAP_EXEC_MAP) | |
702 | ) { | |
703 | /* backing file is not executable, try to copy */ | |
704 | capabilities &= ~BDI_CAP_MAP_DIRECT; | |
705 | } | |
706 | } | |
707 | else { | |
708 | /* anonymous mappings are always memory backed and can be | |
709 | * privately mapped | |
710 | */ | |
711 | capabilities = BDI_CAP_MAP_COPY; | |
712 | ||
713 | /* handle PROT_EXEC implication by PROT_READ */ | |
714 | if ((prot & PROT_READ) && | |
715 | (current->personality & READ_IMPLIES_EXEC)) | |
716 | prot |= PROT_EXEC; | |
717 | } | |
718 | ||
719 | /* allow the security API to have its say */ | |
ed032189 | 720 | ret = security_file_mmap(file, reqprot, prot, flags, addr, 0); |
1da177e4 LT |
721 | if (ret < 0) |
722 | return ret; | |
723 | ||
724 | /* looks okay */ | |
725 | *_capabilities = capabilities; | |
726 | return 0; | |
727 | } | |
728 | ||
729 | /* | |
730 | * we've determined that we can make the mapping, now translate what we | |
731 | * now know into VMA flags | |
732 | */ | |
733 | static unsigned long determine_vm_flags(struct file *file, | |
734 | unsigned long prot, | |
735 | unsigned long flags, | |
736 | unsigned long capabilities) | |
737 | { | |
738 | unsigned long vm_flags; | |
739 | ||
740 | vm_flags = calc_vm_prot_bits(prot) | calc_vm_flag_bits(flags); | |
741 | vm_flags |= VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC; | |
742 | /* vm_flags |= mm->def_flags; */ | |
743 | ||
744 | if (!(capabilities & BDI_CAP_MAP_DIRECT)) { | |
745 | /* attempt to share read-only copies of mapped file chunks */ | |
746 | if (file && !(prot & PROT_WRITE)) | |
747 | vm_flags |= VM_MAYSHARE; | |
748 | } | |
749 | else { | |
750 | /* overlay a shareable mapping on the backing device or inode | |
751 | * if possible - used for chardevs, ramfs/tmpfs/shmfs and | |
752 | * romfs/cramfs */ | |
753 | if (flags & MAP_SHARED) | |
754 | vm_flags |= VM_MAYSHARE | VM_SHARED; | |
755 | else if ((((vm_flags & capabilities) ^ vm_flags) & BDI_CAP_VMFLAGS) == 0) | |
756 | vm_flags |= VM_MAYSHARE; | |
757 | } | |
758 | ||
759 | /* refuse to let anyone share private mappings with this process if | |
760 | * it's being traced - otherwise breakpoints set in it may interfere | |
761 | * with another untraced process | |
762 | */ | |
763 | if ((flags & MAP_PRIVATE) && (current->ptrace & PT_PTRACED)) | |
764 | vm_flags &= ~VM_MAYSHARE; | |
765 | ||
766 | return vm_flags; | |
767 | } | |
768 | ||
769 | /* | |
770 | * set up a shared mapping on a file | |
771 | */ | |
772 | static int do_mmap_shared_file(struct vm_area_struct *vma, unsigned long len) | |
773 | { | |
774 | int ret; | |
775 | ||
776 | ret = vma->vm_file->f_op->mmap(vma->vm_file, vma); | |
777 | if (ret != -ENOSYS) | |
778 | return ret; | |
779 | ||
780 | /* getting an ENOSYS error indicates that direct mmap isn't | |
781 | * possible (as opposed to tried but failed) so we'll fall | |
782 | * through to making a private copy of the data and mapping | |
783 | * that if we can */ | |
784 | return -ENODEV; | |
785 | } | |
786 | ||
787 | /* | |
788 | * set up a private mapping or an anonymous shared mapping | |
789 | */ | |
790 | static int do_mmap_private(struct vm_area_struct *vma, unsigned long len) | |
791 | { | |
792 | void *base; | |
793 | int ret; | |
794 | ||
795 | /* invoke the file's mapping function so that it can keep track of | |
796 | * shared mappings on devices or memory | |
797 | * - VM_MAYSHARE will be set if it may attempt to share | |
798 | */ | |
799 | if (vma->vm_file) { | |
800 | ret = vma->vm_file->f_op->mmap(vma->vm_file, vma); | |
801 | if (ret != -ENOSYS) { | |
802 | /* shouldn't return success if we're not sharing */ | |
803 | BUG_ON(ret == 0 && !(vma->vm_flags & VM_MAYSHARE)); | |
804 | return ret; /* success or a real error */ | |
805 | } | |
806 | ||
807 | /* getting an ENOSYS error indicates that direct mmap isn't | |
808 | * possible (as opposed to tried but failed) so we'll try to | |
809 | * make a private copy of the data and map that instead */ | |
810 | } | |
811 | ||
812 | /* allocate some memory to hold the mapping | |
813 | * - note that this may not return a page-aligned address if the object | |
814 | * we're allocating is smaller than a page | |
815 | */ | |
84097518 | 816 | base = kmalloc(len, GFP_KERNEL|__GFP_COMP); |
1da177e4 LT |
817 | if (!base) |
818 | goto enomem; | |
819 | ||
820 | vma->vm_start = (unsigned long) base; | |
821 | vma->vm_end = vma->vm_start + len; | |
822 | vma->vm_flags |= VM_MAPPED_COPY; | |
823 | ||
824 | #ifdef WARN_ON_SLACK | |
825 | if (len + WARN_ON_SLACK <= kobjsize(result)) | |
826 | printk("Allocation of %lu bytes from process %d has %lu bytes of slack\n", | |
827 | len, current->pid, kobjsize(result) - len); | |
828 | #endif | |
829 | ||
830 | if (vma->vm_file) { | |
831 | /* read the contents of a file into the copy */ | |
832 | mm_segment_t old_fs; | |
833 | loff_t fpos; | |
834 | ||
835 | fpos = vma->vm_pgoff; | |
836 | fpos <<= PAGE_SHIFT; | |
837 | ||
838 | old_fs = get_fs(); | |
839 | set_fs(KERNEL_DS); | |
840 | ret = vma->vm_file->f_op->read(vma->vm_file, base, len, &fpos); | |
841 | set_fs(old_fs); | |
842 | ||
843 | if (ret < 0) | |
844 | goto error_free; | |
845 | ||
846 | /* clear the last little bit */ | |
847 | if (ret < len) | |
848 | memset(base + ret, 0, len - ret); | |
849 | ||
850 | } else { | |
851 | /* if it's an anonymous mapping, then just clear it */ | |
852 | memset(base, 0, len); | |
853 | } | |
854 | ||
855 | return 0; | |
856 | ||
857 | error_free: | |
858 | kfree(base); | |
859 | vma->vm_start = 0; | |
860 | return ret; | |
861 | ||
862 | enomem: | |
863 | printk("Allocation of length %lu from process %d failed\n", | |
864 | len, current->pid); | |
865 | show_free_areas(); | |
866 | return -ENOMEM; | |
867 | } | |
868 | ||
869 | /* | |
870 | * handle mapping creation for uClinux | |
871 | */ | |
872 | unsigned long do_mmap_pgoff(struct file *file, | |
873 | unsigned long addr, | |
874 | unsigned long len, | |
875 | unsigned long prot, | |
876 | unsigned long flags, | |
877 | unsigned long pgoff) | |
878 | { | |
879 | struct vm_list_struct *vml = NULL; | |
880 | struct vm_area_struct *vma = NULL; | |
881 | struct rb_node *rb; | |
882 | unsigned long capabilities, vm_flags; | |
883 | void *result; | |
884 | int ret; | |
885 | ||
7cd94146 EP |
886 | if (!(flags & MAP_FIXED)) |
887 | addr = round_hint_to_min(addr); | |
888 | ||
1da177e4 LT |
889 | /* decide whether we should attempt the mapping, and if so what sort of |
890 | * mapping */ | |
891 | ret = validate_mmap_request(file, addr, len, prot, flags, pgoff, | |
892 | &capabilities); | |
893 | if (ret < 0) | |
894 | return ret; | |
895 | ||
896 | /* we've determined that we can make the mapping, now translate what we | |
897 | * now know into VMA flags */ | |
898 | vm_flags = determine_vm_flags(file, prot, flags, capabilities); | |
899 | ||
900 | /* we're going to need to record the mapping if it works */ | |
4668edc3 | 901 | vml = kzalloc(sizeof(struct vm_list_struct), GFP_KERNEL); |
1da177e4 LT |
902 | if (!vml) |
903 | goto error_getting_vml; | |
1da177e4 LT |
904 | |
905 | down_write(&nommu_vma_sem); | |
906 | ||
907 | /* if we want to share, we need to check for VMAs created by other | |
908 | * mmap() calls that overlap with our proposed mapping | |
909 | * - we can only share with an exact match on most regular files | |
910 | * - shared mappings on character devices and memory backed files are | |
911 | * permitted to overlap inexactly as far as we are concerned for in | |
912 | * these cases, sharing is handled in the driver or filesystem rather | |
913 | * than here | |
914 | */ | |
915 | if (vm_flags & VM_MAYSHARE) { | |
916 | unsigned long pglen = (len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
917 | unsigned long vmpglen; | |
918 | ||
165b2392 DH |
919 | /* suppress VMA sharing for shared regions */ |
920 | if (vm_flags & VM_SHARED && | |
921 | capabilities & BDI_CAP_MAP_DIRECT) | |
922 | goto dont_share_VMAs; | |
923 | ||
1da177e4 LT |
924 | for (rb = rb_first(&nommu_vma_tree); rb; rb = rb_next(rb)) { |
925 | vma = rb_entry(rb, struct vm_area_struct, vm_rb); | |
926 | ||
927 | if (!(vma->vm_flags & VM_MAYSHARE)) | |
928 | continue; | |
929 | ||
930 | /* search for overlapping mappings on the same file */ | |
e9536ae7 | 931 | if (vma->vm_file->f_path.dentry->d_inode != file->f_path.dentry->d_inode) |
1da177e4 LT |
932 | continue; |
933 | ||
934 | if (vma->vm_pgoff >= pgoff + pglen) | |
935 | continue; | |
936 | ||
937 | vmpglen = vma->vm_end - vma->vm_start + PAGE_SIZE - 1; | |
938 | vmpglen >>= PAGE_SHIFT; | |
939 | if (pgoff >= vma->vm_pgoff + vmpglen) | |
940 | continue; | |
941 | ||
942 | /* handle inexactly overlapping matches between mappings */ | |
943 | if (vma->vm_pgoff != pgoff || vmpglen != pglen) { | |
944 | if (!(capabilities & BDI_CAP_MAP_DIRECT)) | |
945 | goto sharing_violation; | |
946 | continue; | |
947 | } | |
948 | ||
949 | /* we've found a VMA we can share */ | |
950 | atomic_inc(&vma->vm_usage); | |
951 | ||
952 | vml->vma = vma; | |
953 | result = (void *) vma->vm_start; | |
954 | goto shared; | |
955 | } | |
956 | ||
165b2392 | 957 | dont_share_VMAs: |
1da177e4 LT |
958 | vma = NULL; |
959 | ||
960 | /* obtain the address at which to make a shared mapping | |
961 | * - this is the hook for quasi-memory character devices to | |
962 | * tell us the location of a shared mapping | |
963 | */ | |
964 | if (file && file->f_op->get_unmapped_area) { | |
965 | addr = file->f_op->get_unmapped_area(file, addr, len, | |
966 | pgoff, flags); | |
967 | if (IS_ERR((void *) addr)) { | |
968 | ret = addr; | |
969 | if (ret != (unsigned long) -ENOSYS) | |
970 | goto error; | |
971 | ||
972 | /* the driver refused to tell us where to site | |
973 | * the mapping so we'll have to attempt to copy | |
974 | * it */ | |
975 | ret = (unsigned long) -ENODEV; | |
976 | if (!(capabilities & BDI_CAP_MAP_COPY)) | |
977 | goto error; | |
978 | ||
979 | capabilities &= ~BDI_CAP_MAP_DIRECT; | |
980 | } | |
981 | } | |
982 | } | |
983 | ||
984 | /* we're going to need a VMA struct as well */ | |
4668edc3 | 985 | vma = kzalloc(sizeof(struct vm_area_struct), GFP_KERNEL); |
1da177e4 LT |
986 | if (!vma) |
987 | goto error_getting_vma; | |
988 | ||
1da177e4 LT |
989 | INIT_LIST_HEAD(&vma->anon_vma_node); |
990 | atomic_set(&vma->vm_usage, 1); | |
925d1c40 | 991 | if (file) { |
1da177e4 | 992 | get_file(file); |
925d1c40 MH |
993 | if (vm_flags & VM_EXECUTABLE) { |
994 | added_exe_file_vma(current->mm); | |
995 | vma->vm_mm = current->mm; | |
996 | } | |
997 | } | |
1da177e4 LT |
998 | vma->vm_file = file; |
999 | vma->vm_flags = vm_flags; | |
1000 | vma->vm_start = addr; | |
1001 | vma->vm_end = addr + len; | |
1002 | vma->vm_pgoff = pgoff; | |
1003 | ||
1004 | vml->vma = vma; | |
1005 | ||
1006 | /* set up the mapping */ | |
1007 | if (file && vma->vm_flags & VM_SHARED) | |
1008 | ret = do_mmap_shared_file(vma, len); | |
1009 | else | |
1010 | ret = do_mmap_private(vma, len); | |
1011 | if (ret < 0) | |
1012 | goto error; | |
1013 | ||
1014 | /* okay... we have a mapping; now we have to register it */ | |
1015 | result = (void *) vma->vm_start; | |
1016 | ||
1017 | if (vma->vm_flags & VM_MAPPED_COPY) { | |
1018 | realalloc += kobjsize(result); | |
1019 | askedalloc += len; | |
1020 | } | |
1021 | ||
1022 | realalloc += kobjsize(vma); | |
1023 | askedalloc += sizeof(*vma); | |
1024 | ||
1025 | current->mm->total_vm += len >> PAGE_SHIFT; | |
1026 | ||
1027 | add_nommu_vma(vma); | |
1028 | ||
1029 | shared: | |
1030 | realalloc += kobjsize(vml); | |
1031 | askedalloc += sizeof(*vml); | |
1032 | ||
3034097a | 1033 | add_vma_to_mm(current->mm, vml); |
1da177e4 LT |
1034 | |
1035 | up_write(&nommu_vma_sem); | |
1036 | ||
1037 | if (prot & PROT_EXEC) | |
1038 | flush_icache_range((unsigned long) result, | |
1039 | (unsigned long) result + len); | |
1040 | ||
1041 | #ifdef DEBUG | |
1042 | printk("do_mmap:\n"); | |
1043 | show_process_blocks(); | |
1044 | #endif | |
1045 | ||
1046 | return (unsigned long) result; | |
1047 | ||
1048 | error: | |
1049 | up_write(&nommu_vma_sem); | |
1050 | kfree(vml); | |
1051 | if (vma) { | |
925d1c40 | 1052 | if (vma->vm_file) { |
3fcd03e0 | 1053 | fput(vma->vm_file); |
925d1c40 MH |
1054 | if (vma->vm_flags & VM_EXECUTABLE) |
1055 | removed_exe_file_vma(vma->vm_mm); | |
1056 | } | |
1da177e4 LT |
1057 | kfree(vma); |
1058 | } | |
1059 | return ret; | |
1060 | ||
1061 | sharing_violation: | |
1062 | up_write(&nommu_vma_sem); | |
1063 | printk("Attempt to share mismatched mappings\n"); | |
1064 | kfree(vml); | |
1065 | return -EINVAL; | |
1066 | ||
1067 | error_getting_vma: | |
1068 | up_write(&nommu_vma_sem); | |
1069 | kfree(vml); | |
66aa2b4b | 1070 | printk("Allocation of vma for %lu byte allocation from process %d failed\n", |
1da177e4 LT |
1071 | len, current->pid); |
1072 | show_free_areas(); | |
1073 | return -ENOMEM; | |
1074 | ||
1075 | error_getting_vml: | |
1076 | printk("Allocation of vml for %lu byte allocation from process %d failed\n", | |
1077 | len, current->pid); | |
1078 | show_free_areas(); | |
1079 | return -ENOMEM; | |
1080 | } | |
b5073173 | 1081 | EXPORT_SYMBOL(do_mmap_pgoff); |
1da177e4 LT |
1082 | |
1083 | /* | |
1084 | * handle mapping disposal for uClinux | |
1085 | */ | |
925d1c40 | 1086 | static void put_vma(struct mm_struct *mm, struct vm_area_struct *vma) |
1da177e4 LT |
1087 | { |
1088 | if (vma) { | |
1089 | down_write(&nommu_vma_sem); | |
1090 | ||
1091 | if (atomic_dec_and_test(&vma->vm_usage)) { | |
1092 | delete_nommu_vma(vma); | |
1093 | ||
1094 | if (vma->vm_ops && vma->vm_ops->close) | |
1095 | vma->vm_ops->close(vma); | |
1096 | ||
1097 | /* IO memory and memory shared directly out of the pagecache from | |
1098 | * ramfs/tmpfs mustn't be released here */ | |
1099 | if (vma->vm_flags & VM_MAPPED_COPY) { | |
1100 | realalloc -= kobjsize((void *) vma->vm_start); | |
1101 | askedalloc -= vma->vm_end - vma->vm_start; | |
1102 | kfree((void *) vma->vm_start); | |
1103 | } | |
1104 | ||
1105 | realalloc -= kobjsize(vma); | |
1106 | askedalloc -= sizeof(*vma); | |
1107 | ||
925d1c40 | 1108 | if (vma->vm_file) { |
1da177e4 | 1109 | fput(vma->vm_file); |
925d1c40 MH |
1110 | if (vma->vm_flags & VM_EXECUTABLE) |
1111 | removed_exe_file_vma(mm); | |
1112 | } | |
1da177e4 LT |
1113 | kfree(vma); |
1114 | } | |
1115 | ||
1116 | up_write(&nommu_vma_sem); | |
1117 | } | |
1118 | } | |
1119 | ||
3034097a DH |
1120 | /* |
1121 | * release a mapping | |
1122 | * - under NOMMU conditions the parameters must match exactly to the mapping to | |
1123 | * be removed | |
1124 | */ | |
1da177e4 LT |
1125 | int do_munmap(struct mm_struct *mm, unsigned long addr, size_t len) |
1126 | { | |
1127 | struct vm_list_struct *vml, **parent; | |
1128 | unsigned long end = addr + len; | |
1129 | ||
1130 | #ifdef DEBUG | |
1131 | printk("do_munmap:\n"); | |
1132 | #endif | |
1133 | ||
3034097a DH |
1134 | for (parent = &mm->context.vmlist; *parent; parent = &(*parent)->next) { |
1135 | if ((*parent)->vma->vm_start > addr) | |
1136 | break; | |
1da177e4 | 1137 | if ((*parent)->vma->vm_start == addr && |
66aa2b4b | 1138 | ((len == 0) || ((*parent)->vma->vm_end == end))) |
1da177e4 | 1139 | goto found; |
3034097a | 1140 | } |
1da177e4 LT |
1141 | |
1142 | printk("munmap of non-mmaped memory by process %d (%s): %p\n", | |
1143 | current->pid, current->comm, (void *) addr); | |
1144 | return -EINVAL; | |
1145 | ||
1146 | found: | |
1147 | vml = *parent; | |
1148 | ||
925d1c40 | 1149 | put_vma(mm, vml->vma); |
1da177e4 LT |
1150 | |
1151 | *parent = vml->next; | |
1152 | realalloc -= kobjsize(vml); | |
1153 | askedalloc -= sizeof(*vml); | |
1154 | kfree(vml); | |
365e9c87 HD |
1155 | |
1156 | update_hiwater_vm(mm); | |
1da177e4 LT |
1157 | mm->total_vm -= len >> PAGE_SHIFT; |
1158 | ||
1159 | #ifdef DEBUG | |
1160 | show_process_blocks(); | |
1161 | #endif | |
1162 | ||
1163 | return 0; | |
1164 | } | |
b5073173 | 1165 | EXPORT_SYMBOL(do_munmap); |
1da177e4 | 1166 | |
3034097a DH |
1167 | asmlinkage long sys_munmap(unsigned long addr, size_t len) |
1168 | { | |
1169 | int ret; | |
1170 | struct mm_struct *mm = current->mm; | |
1171 | ||
1172 | down_write(&mm->mmap_sem); | |
1173 | ret = do_munmap(mm, addr, len); | |
1174 | up_write(&mm->mmap_sem); | |
1175 | return ret; | |
1176 | } | |
1177 | ||
1178 | /* | |
1179 | * Release all mappings | |
1180 | */ | |
1da177e4 LT |
1181 | void exit_mmap(struct mm_struct * mm) |
1182 | { | |
1183 | struct vm_list_struct *tmp; | |
1184 | ||
1185 | if (mm) { | |
1186 | #ifdef DEBUG | |
1187 | printk("Exit_mmap:\n"); | |
1188 | #endif | |
1189 | ||
1190 | mm->total_vm = 0; | |
1191 | ||
1192 | while ((tmp = mm->context.vmlist)) { | |
1193 | mm->context.vmlist = tmp->next; | |
925d1c40 | 1194 | put_vma(mm, tmp->vma); |
1da177e4 LT |
1195 | |
1196 | realalloc -= kobjsize(tmp); | |
1197 | askedalloc -= sizeof(*tmp); | |
1198 | kfree(tmp); | |
1199 | } | |
1200 | ||
1201 | #ifdef DEBUG | |
1202 | show_process_blocks(); | |
1203 | #endif | |
1204 | } | |
1205 | } | |
1206 | ||
1da177e4 LT |
1207 | unsigned long do_brk(unsigned long addr, unsigned long len) |
1208 | { | |
1209 | return -ENOMEM; | |
1210 | } | |
1211 | ||
1212 | /* | |
6fa5f80b DH |
1213 | * expand (or shrink) an existing mapping, potentially moving it at the same |
1214 | * time (controlled by the MREMAP_MAYMOVE flag and available VM space) | |
1da177e4 | 1215 | * |
6fa5f80b DH |
1216 | * under NOMMU conditions, we only permit changing a mapping's size, and only |
1217 | * as long as it stays within the hole allocated by the kmalloc() call in | |
1218 | * do_mmap_pgoff() and the block is not shareable | |
1da177e4 | 1219 | * |
6fa5f80b | 1220 | * MREMAP_FIXED is not supported under NOMMU conditions |
1da177e4 LT |
1221 | */ |
1222 | unsigned long do_mremap(unsigned long addr, | |
1223 | unsigned long old_len, unsigned long new_len, | |
1224 | unsigned long flags, unsigned long new_addr) | |
1225 | { | |
6fa5f80b | 1226 | struct vm_area_struct *vma; |
1da177e4 LT |
1227 | |
1228 | /* insanity checks first */ | |
1229 | if (new_len == 0) | |
1230 | return (unsigned long) -EINVAL; | |
1231 | ||
1232 | if (flags & MREMAP_FIXED && new_addr != addr) | |
1233 | return (unsigned long) -EINVAL; | |
1234 | ||
6fa5f80b DH |
1235 | vma = find_vma_exact(current->mm, addr); |
1236 | if (!vma) | |
1237 | return (unsigned long) -EINVAL; | |
1da177e4 | 1238 | |
6fa5f80b | 1239 | if (vma->vm_end != vma->vm_start + old_len) |
1da177e4 LT |
1240 | return (unsigned long) -EFAULT; |
1241 | ||
6fa5f80b | 1242 | if (vma->vm_flags & VM_MAYSHARE) |
1da177e4 LT |
1243 | return (unsigned long) -EPERM; |
1244 | ||
1245 | if (new_len > kobjsize((void *) addr)) | |
1246 | return (unsigned long) -ENOMEM; | |
1247 | ||
1248 | /* all checks complete - do it */ | |
6fa5f80b | 1249 | vma->vm_end = vma->vm_start + new_len; |
1da177e4 LT |
1250 | |
1251 | askedalloc -= old_len; | |
1252 | askedalloc += new_len; | |
1253 | ||
6fa5f80b DH |
1254 | return vma->vm_start; |
1255 | } | |
b5073173 | 1256 | EXPORT_SYMBOL(do_mremap); |
6fa5f80b DH |
1257 | |
1258 | asmlinkage unsigned long sys_mremap(unsigned long addr, | |
1259 | unsigned long old_len, unsigned long new_len, | |
1260 | unsigned long flags, unsigned long new_addr) | |
1261 | { | |
1262 | unsigned long ret; | |
1263 | ||
1264 | down_write(¤t->mm->mmap_sem); | |
1265 | ret = do_mremap(addr, old_len, new_len, flags, new_addr); | |
1266 | up_write(¤t->mm->mmap_sem); | |
1267 | return ret; | |
1da177e4 LT |
1268 | } |
1269 | ||
6aab341e | 1270 | struct page *follow_page(struct vm_area_struct *vma, unsigned long address, |
deceb6cd | 1271 | unsigned int foll_flags) |
1da177e4 LT |
1272 | { |
1273 | return NULL; | |
1274 | } | |
1275 | ||
1da177e4 LT |
1276 | int remap_pfn_range(struct vm_area_struct *vma, unsigned long from, |
1277 | unsigned long to, unsigned long size, pgprot_t prot) | |
1278 | { | |
66aa2b4b GU |
1279 | vma->vm_start = vma->vm_pgoff << PAGE_SHIFT; |
1280 | return 0; | |
1da177e4 | 1281 | } |
22c4af40 | 1282 | EXPORT_SYMBOL(remap_pfn_range); |
1da177e4 | 1283 | |
f905bc44 PM |
1284 | int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, |
1285 | unsigned long pgoff) | |
1286 | { | |
1287 | unsigned int size = vma->vm_end - vma->vm_start; | |
1288 | ||
1289 | if (!(vma->vm_flags & VM_USERMAP)) | |
1290 | return -EINVAL; | |
1291 | ||
1292 | vma->vm_start = (unsigned long)(addr + (pgoff << PAGE_SHIFT)); | |
1293 | vma->vm_end = vma->vm_start + size; | |
1294 | ||
1295 | return 0; | |
1296 | } | |
1297 | EXPORT_SYMBOL(remap_vmalloc_range); | |
1298 | ||
1da177e4 LT |
1299 | void swap_unplug_io_fn(struct backing_dev_info *bdi, struct page *page) |
1300 | { | |
1301 | } | |
1302 | ||
1303 | unsigned long arch_get_unmapped_area(struct file *file, unsigned long addr, | |
1304 | unsigned long len, unsigned long pgoff, unsigned long flags) | |
1305 | { | |
1306 | return -ENOMEM; | |
1307 | } | |
1308 | ||
1363c3cd | 1309 | void arch_unmap_area(struct mm_struct *mm, unsigned long addr) |
1da177e4 LT |
1310 | { |
1311 | } | |
1312 | ||
1da177e4 LT |
1313 | void unmap_mapping_range(struct address_space *mapping, |
1314 | loff_t const holebegin, loff_t const holelen, | |
1315 | int even_cows) | |
1316 | { | |
1317 | } | |
22c4af40 | 1318 | EXPORT_SYMBOL(unmap_mapping_range); |
1da177e4 | 1319 | |
d56e03cd DH |
1320 | /* |
1321 | * ask for an unmapped area at which to create a mapping on a file | |
1322 | */ | |
1323 | unsigned long get_unmapped_area(struct file *file, unsigned long addr, | |
1324 | unsigned long len, unsigned long pgoff, | |
1325 | unsigned long flags) | |
1326 | { | |
1327 | unsigned long (*get_area)(struct file *, unsigned long, unsigned long, | |
1328 | unsigned long, unsigned long); | |
1329 | ||
1330 | get_area = current->mm->get_unmapped_area; | |
1331 | if (file && file->f_op && file->f_op->get_unmapped_area) | |
1332 | get_area = file->f_op->get_unmapped_area; | |
1333 | ||
1334 | if (!get_area) | |
1335 | return -ENOSYS; | |
1336 | ||
1337 | return get_area(file, addr, len, pgoff, flags); | |
1338 | } | |
d56e03cd DH |
1339 | EXPORT_SYMBOL(get_unmapped_area); |
1340 | ||
1da177e4 LT |
1341 | /* |
1342 | * Check that a process has enough memory to allocate a new virtual | |
1343 | * mapping. 0 means there is enough memory for the allocation to | |
1344 | * succeed and -ENOMEM implies there is not. | |
1345 | * | |
1346 | * We currently support three overcommit policies, which are set via the | |
1347 | * vm.overcommit_memory sysctl. See Documentation/vm/overcommit-accounting | |
1348 | * | |
1349 | * Strict overcommit modes added 2002 Feb 26 by Alan Cox. | |
1350 | * Additional code 2002 Jul 20 by Robert Love. | |
1351 | * | |
1352 | * cap_sys_admin is 1 if the process has admin privileges, 0 otherwise. | |
1353 | * | |
1354 | * Note this is a helper function intended to be used by LSMs which | |
1355 | * wish to use this logic. | |
1356 | */ | |
34b4e4aa | 1357 | int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin) |
1da177e4 LT |
1358 | { |
1359 | unsigned long free, allowed; | |
1360 | ||
1361 | vm_acct_memory(pages); | |
1362 | ||
1363 | /* | |
1364 | * Sometimes we want to use more memory than we have | |
1365 | */ | |
1366 | if (sysctl_overcommit_memory == OVERCOMMIT_ALWAYS) | |
1367 | return 0; | |
1368 | ||
1369 | if (sysctl_overcommit_memory == OVERCOMMIT_GUESS) { | |
1370 | unsigned long n; | |
1371 | ||
347ce434 | 1372 | free = global_page_state(NR_FILE_PAGES); |
1da177e4 LT |
1373 | free += nr_swap_pages; |
1374 | ||
1375 | /* | |
1376 | * Any slabs which are created with the | |
1377 | * SLAB_RECLAIM_ACCOUNT flag claim to have contents | |
1378 | * which are reclaimable, under pressure. The dentry | |
1379 | * cache and most inode caches should fall into this | |
1380 | */ | |
972d1a7b | 1381 | free += global_page_state(NR_SLAB_RECLAIMABLE); |
1da177e4 LT |
1382 | |
1383 | /* | |
1384 | * Leave the last 3% for root | |
1385 | */ | |
1386 | if (!cap_sys_admin) | |
1387 | free -= free / 32; | |
1388 | ||
1389 | if (free > pages) | |
1390 | return 0; | |
1391 | ||
1392 | /* | |
1393 | * nr_free_pages() is very expensive on large systems, | |
1394 | * only call if we're about to fail. | |
1395 | */ | |
1396 | n = nr_free_pages(); | |
d5ddc79b HA |
1397 | |
1398 | /* | |
1399 | * Leave reserved pages. The pages are not for anonymous pages. | |
1400 | */ | |
1401 | if (n <= totalreserve_pages) | |
1402 | goto error; | |
1403 | else | |
1404 | n -= totalreserve_pages; | |
1405 | ||
1406 | /* | |
1407 | * Leave the last 3% for root | |
1408 | */ | |
1da177e4 LT |
1409 | if (!cap_sys_admin) |
1410 | n -= n / 32; | |
1411 | free += n; | |
1412 | ||
1413 | if (free > pages) | |
1414 | return 0; | |
d5ddc79b HA |
1415 | |
1416 | goto error; | |
1da177e4 LT |
1417 | } |
1418 | ||
1419 | allowed = totalram_pages * sysctl_overcommit_ratio / 100; | |
1420 | /* | |
1421 | * Leave the last 3% for root | |
1422 | */ | |
1423 | if (!cap_sys_admin) | |
1424 | allowed -= allowed / 32; | |
1425 | allowed += total_swap_pages; | |
1426 | ||
1427 | /* Don't let a single process grow too big: | |
1428 | leave 3% of the size of this process for other processes */ | |
1429 | allowed -= current->mm->total_vm / 32; | |
1430 | ||
2f60f8d3 SD |
1431 | /* |
1432 | * cast `allowed' as a signed long because vm_committed_space | |
1433 | * sometimes has a negative value | |
1434 | */ | |
80119ef5 | 1435 | if (atomic_long_read(&vm_committed_space) < (long)allowed) |
1da177e4 | 1436 | return 0; |
d5ddc79b | 1437 | error: |
1da177e4 LT |
1438 | vm_unacct_memory(pages); |
1439 | ||
1440 | return -ENOMEM; | |
1441 | } | |
1442 | ||
1443 | int in_gate_area_no_task(unsigned long addr) | |
1444 | { | |
1445 | return 0; | |
1446 | } | |
b0e15190 | 1447 | |
d0217ac0 | 1448 | int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
b0e15190 DH |
1449 | { |
1450 | BUG(); | |
d0217ac0 | 1451 | return 0; |
b0e15190 | 1452 | } |
b5073173 | 1453 | EXPORT_SYMBOL(filemap_fault); |
0ec76a11 DH |
1454 | |
1455 | /* | |
1456 | * Access another process' address space. | |
1457 | * - source/target buffer must be kernel space | |
1458 | */ | |
1459 | int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write) | |
1460 | { | |
0ec76a11 DH |
1461 | struct vm_area_struct *vma; |
1462 | struct mm_struct *mm; | |
1463 | ||
1464 | if (addr + len < addr) | |
1465 | return 0; | |
1466 | ||
1467 | mm = get_task_mm(tsk); | |
1468 | if (!mm) | |
1469 | return 0; | |
1470 | ||
1471 | down_read(&mm->mmap_sem); | |
1472 | ||
1473 | /* the access must start within one of the target process's mappings */ | |
0159b141 DH |
1474 | vma = find_vma(mm, addr); |
1475 | if (vma) { | |
0ec76a11 DH |
1476 | /* don't overrun this mapping */ |
1477 | if (addr + len >= vma->vm_end) | |
1478 | len = vma->vm_end - addr; | |
1479 | ||
1480 | /* only read or write mappings where it is permitted */ | |
d00c7b99 | 1481 | if (write && vma->vm_flags & VM_MAYWRITE) |
0ec76a11 | 1482 | len -= copy_to_user((void *) addr, buf, len); |
d00c7b99 | 1483 | else if (!write && vma->vm_flags & VM_MAYREAD) |
0ec76a11 DH |
1484 | len -= copy_from_user(buf, (void *) addr, len); |
1485 | else | |
1486 | len = 0; | |
1487 | } else { | |
1488 | len = 0; | |
1489 | } | |
1490 | ||
1491 | up_read(&mm->mmap_sem); | |
1492 | mmput(mm); | |
1493 | return len; | |
1494 | } |