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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> | |
fa8e26cc | 25 | #include <linux/tracehook.h> |
1da177e4 LT |
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 | ||
b291f000 NP |
37 | #include "internal.h" |
38 | ||
1da177e4 LT |
39 | void *high_memory; |
40 | struct page *mem_map; | |
41 | unsigned long max_mapnr; | |
42 | unsigned long num_physpages; | |
80119ef5 | 43 | atomic_long_t vm_committed_space = ATOMIC_LONG_INIT(0); |
1da177e4 LT |
44 | int sysctl_overcommit_memory = OVERCOMMIT_GUESS; /* heuristic overcommit */ |
45 | int sysctl_overcommit_ratio = 50; /* default is 50% */ | |
46 | int sysctl_max_map_count = DEFAULT_MAX_MAP_COUNT; | |
47 | int heap_stack_gap = 0; | |
48 | ||
49 | EXPORT_SYMBOL(mem_map); | |
6a04de6d | 50 | EXPORT_SYMBOL(num_physpages); |
1da177e4 LT |
51 | |
52 | /* list of shareable VMAs */ | |
53 | struct rb_root nommu_vma_tree = RB_ROOT; | |
54 | DECLARE_RWSEM(nommu_vma_sem); | |
55 | ||
56 | struct vm_operations_struct generic_file_vm_ops = { | |
57 | }; | |
58 | ||
59 | /* | |
60 | * Handle all mappings that got truncated by a "truncate()" | |
61 | * system call. | |
62 | * | |
63 | * NOTE! We have to be ready to update the memory sharing | |
64 | * between the file and the memory map for a potential last | |
65 | * incomplete page. Ugly, but necessary. | |
66 | */ | |
67 | int vmtruncate(struct inode *inode, loff_t offset) | |
68 | { | |
69 | struct address_space *mapping = inode->i_mapping; | |
70 | unsigned long limit; | |
71 | ||
72 | if (inode->i_size < offset) | |
73 | goto do_expand; | |
74 | i_size_write(inode, offset); | |
75 | ||
76 | truncate_inode_pages(mapping, offset); | |
77 | goto out_truncate; | |
78 | ||
79 | do_expand: | |
80 | limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur; | |
81 | if (limit != RLIM_INFINITY && offset > limit) | |
82 | goto out_sig; | |
83 | if (offset > inode->i_sb->s_maxbytes) | |
84 | goto out; | |
85 | i_size_write(inode, offset); | |
86 | ||
87 | out_truncate: | |
acfa4380 | 88 | if (inode->i_op->truncate) |
1da177e4 LT |
89 | inode->i_op->truncate(inode); |
90 | return 0; | |
91 | out_sig: | |
92 | send_sig(SIGXFSZ, current, 0); | |
93 | out: | |
94 | return -EFBIG; | |
95 | } | |
96 | ||
97 | EXPORT_SYMBOL(vmtruncate); | |
98 | ||
99 | /* | |
100 | * Return the total memory allocated for this pointer, not | |
101 | * just what the caller asked for. | |
102 | * | |
103 | * Doesn't have to be accurate, i.e. may have races. | |
104 | */ | |
105 | unsigned int kobjsize(const void *objp) | |
106 | { | |
107 | struct page *page; | |
108 | ||
4016a139 MH |
109 | /* |
110 | * If the object we have should not have ksize performed on it, | |
111 | * return size of 0 | |
112 | */ | |
5a1603be | 113 | if (!objp || !virt_addr_valid(objp)) |
6cfd53fc PM |
114 | return 0; |
115 | ||
116 | page = virt_to_head_page(objp); | |
6cfd53fc PM |
117 | |
118 | /* | |
119 | * If the allocator sets PageSlab, we know the pointer came from | |
120 | * kmalloc(). | |
121 | */ | |
1da177e4 LT |
122 | if (PageSlab(page)) |
123 | return ksize(objp); | |
124 | ||
6cfd53fc PM |
125 | /* |
126 | * The ksize() function is only guaranteed to work for pointers | |
5a1603be | 127 | * returned by kmalloc(). So handle arbitrary pointers here. |
6cfd53fc | 128 | */ |
5a1603be | 129 | return PAGE_SIZE << compound_order(page); |
1da177e4 LT |
130 | } |
131 | ||
b291f000 NP |
132 | int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, |
133 | unsigned long start, int len, int flags, | |
134 | struct page **pages, struct vm_area_struct **vmas) | |
1da177e4 | 135 | { |
910e46da | 136 | struct vm_area_struct *vma; |
7b4d5b8b DH |
137 | unsigned long vm_flags; |
138 | int i; | |
b291f000 NP |
139 | int write = !!(flags & GUP_FLAGS_WRITE); |
140 | int force = !!(flags & GUP_FLAGS_FORCE); | |
141 | int ignore = !!(flags & GUP_FLAGS_IGNORE_VMA_PERMISSIONS); | |
7b4d5b8b DH |
142 | |
143 | /* calculate required read or write permissions. | |
144 | * - if 'force' is set, we only require the "MAY" flags. | |
145 | */ | |
146 | vm_flags = write ? (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD); | |
147 | vm_flags &= force ? (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE); | |
1da177e4 LT |
148 | |
149 | for (i = 0; i < len; i++) { | |
910e46da | 150 | vma = find_vma(mm, start); |
7b4d5b8b DH |
151 | if (!vma) |
152 | goto finish_or_fault; | |
153 | ||
154 | /* protect what we can, including chardevs */ | |
155 | if (vma->vm_flags & (VM_IO | VM_PFNMAP) || | |
b291f000 | 156 | (!ignore && !(vm_flags & vma->vm_flags))) |
7b4d5b8b | 157 | goto finish_or_fault; |
910e46da | 158 | |
1da177e4 LT |
159 | if (pages) { |
160 | pages[i] = virt_to_page(start); | |
161 | if (pages[i]) | |
162 | page_cache_get(pages[i]); | |
163 | } | |
164 | if (vmas) | |
910e46da | 165 | vmas[i] = vma; |
1da177e4 LT |
166 | start += PAGE_SIZE; |
167 | } | |
7b4d5b8b DH |
168 | |
169 | return i; | |
170 | ||
171 | finish_or_fault: | |
172 | return i ? : -EFAULT; | |
1da177e4 | 173 | } |
b291f000 NP |
174 | |
175 | ||
176 | /* | |
177 | * get a list of pages in an address range belonging to the specified process | |
178 | * and indicate the VMA that covers each page | |
179 | * - this is potentially dodgy as we may end incrementing the page count of a | |
180 | * slab page or a secondary page from a compound page | |
181 | * - don't permit access to VMAs that don't support it, such as I/O mappings | |
182 | */ | |
183 | int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, | |
184 | unsigned long start, int len, int write, int force, | |
185 | struct page **pages, struct vm_area_struct **vmas) | |
186 | { | |
187 | int flags = 0; | |
188 | ||
189 | if (write) | |
190 | flags |= GUP_FLAGS_WRITE; | |
191 | if (force) | |
192 | flags |= GUP_FLAGS_FORCE; | |
193 | ||
194 | return __get_user_pages(tsk, mm, | |
195 | start, len, flags, | |
196 | pages, vmas); | |
197 | } | |
66aa2b4b GU |
198 | EXPORT_SYMBOL(get_user_pages); |
199 | ||
1da177e4 LT |
200 | DEFINE_RWLOCK(vmlist_lock); |
201 | struct vm_struct *vmlist; | |
202 | ||
b3bdda02 | 203 | void vfree(const void *addr) |
1da177e4 LT |
204 | { |
205 | kfree(addr); | |
206 | } | |
b5073173 | 207 | EXPORT_SYMBOL(vfree); |
1da177e4 | 208 | |
dd0fc66f | 209 | void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot) |
1da177e4 LT |
210 | { |
211 | /* | |
8518609d RD |
212 | * You can't specify __GFP_HIGHMEM with kmalloc() since kmalloc() |
213 | * returns only a logical address. | |
1da177e4 | 214 | */ |
84097518 | 215 | return kmalloc(size, (gfp_mask | __GFP_COMP) & ~__GFP_HIGHMEM); |
1da177e4 | 216 | } |
b5073173 | 217 | EXPORT_SYMBOL(__vmalloc); |
1da177e4 | 218 | |
f905bc44 PM |
219 | void *vmalloc_user(unsigned long size) |
220 | { | |
221 | void *ret; | |
222 | ||
223 | ret = __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO, | |
224 | PAGE_KERNEL); | |
225 | if (ret) { | |
226 | struct vm_area_struct *vma; | |
227 | ||
228 | down_write(¤t->mm->mmap_sem); | |
229 | vma = find_vma(current->mm, (unsigned long)ret); | |
230 | if (vma) | |
231 | vma->vm_flags |= VM_USERMAP; | |
232 | up_write(¤t->mm->mmap_sem); | |
233 | } | |
234 | ||
235 | return ret; | |
236 | } | |
237 | EXPORT_SYMBOL(vmalloc_user); | |
238 | ||
b3bdda02 | 239 | struct page *vmalloc_to_page(const void *addr) |
1da177e4 LT |
240 | { |
241 | return virt_to_page(addr); | |
242 | } | |
b5073173 | 243 | EXPORT_SYMBOL(vmalloc_to_page); |
1da177e4 | 244 | |
b3bdda02 | 245 | unsigned long vmalloc_to_pfn(const void *addr) |
1da177e4 LT |
246 | { |
247 | return page_to_pfn(virt_to_page(addr)); | |
248 | } | |
b5073173 | 249 | EXPORT_SYMBOL(vmalloc_to_pfn); |
1da177e4 LT |
250 | |
251 | long vread(char *buf, char *addr, unsigned long count) | |
252 | { | |
253 | memcpy(buf, addr, count); | |
254 | return count; | |
255 | } | |
256 | ||
257 | long vwrite(char *buf, char *addr, unsigned long count) | |
258 | { | |
259 | /* Don't allow overflow */ | |
260 | if ((unsigned long) addr + count < count) | |
261 | count = -(unsigned long) addr; | |
262 | ||
263 | memcpy(addr, buf, count); | |
264 | return(count); | |
265 | } | |
266 | ||
267 | /* | |
268 | * vmalloc - allocate virtually continguos memory | |
269 | * | |
270 | * @size: allocation size | |
271 | * | |
272 | * Allocate enough pages to cover @size from the page level | |
273 | * allocator and map them into continguos kernel virtual space. | |
274 | * | |
c1c8897f | 275 | * For tight control over page level allocator and protection flags |
1da177e4 LT |
276 | * use __vmalloc() instead. |
277 | */ | |
278 | void *vmalloc(unsigned long size) | |
279 | { | |
280 | return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL); | |
281 | } | |
f6138882 AM |
282 | EXPORT_SYMBOL(vmalloc); |
283 | ||
284 | void *vmalloc_node(unsigned long size, int node) | |
285 | { | |
286 | return vmalloc(size); | |
287 | } | |
288 | EXPORT_SYMBOL(vmalloc_node); | |
1da177e4 | 289 | |
1af446ed PM |
290 | #ifndef PAGE_KERNEL_EXEC |
291 | # define PAGE_KERNEL_EXEC PAGE_KERNEL | |
292 | #endif | |
293 | ||
294 | /** | |
295 | * vmalloc_exec - allocate virtually contiguous, executable memory | |
296 | * @size: allocation size | |
297 | * | |
298 | * Kernel-internal function to allocate enough pages to cover @size | |
299 | * the page level allocator and map them into contiguous and | |
300 | * executable kernel virtual space. | |
301 | * | |
302 | * For tight control over page level allocator and protection flags | |
303 | * use __vmalloc() instead. | |
304 | */ | |
305 | ||
306 | void *vmalloc_exec(unsigned long size) | |
307 | { | |
308 | return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC); | |
309 | } | |
310 | ||
b5073173 PM |
311 | /** |
312 | * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) | |
1da177e4 LT |
313 | * @size: allocation size |
314 | * | |
315 | * Allocate enough 32bit PA addressable pages to cover @size from the | |
316 | * page level allocator and map them into continguos kernel virtual space. | |
317 | */ | |
318 | void *vmalloc_32(unsigned long size) | |
319 | { | |
320 | return __vmalloc(size, GFP_KERNEL, PAGE_KERNEL); | |
321 | } | |
b5073173 PM |
322 | EXPORT_SYMBOL(vmalloc_32); |
323 | ||
324 | /** | |
325 | * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory | |
326 | * @size: allocation size | |
327 | * | |
328 | * The resulting memory area is 32bit addressable and zeroed so it can be | |
329 | * mapped to userspace without leaking data. | |
f905bc44 PM |
330 | * |
331 | * VM_USERMAP is set on the corresponding VMA so that subsequent calls to | |
332 | * remap_vmalloc_range() are permissible. | |
b5073173 PM |
333 | */ |
334 | void *vmalloc_32_user(unsigned long size) | |
335 | { | |
f905bc44 PM |
336 | /* |
337 | * We'll have to sort out the ZONE_DMA bits for 64-bit, | |
338 | * but for now this can simply use vmalloc_user() directly. | |
339 | */ | |
340 | return vmalloc_user(size); | |
b5073173 PM |
341 | } |
342 | EXPORT_SYMBOL(vmalloc_32_user); | |
1da177e4 LT |
343 | |
344 | void *vmap(struct page **pages, unsigned int count, unsigned long flags, pgprot_t prot) | |
345 | { | |
346 | BUG(); | |
347 | return NULL; | |
348 | } | |
b5073173 | 349 | EXPORT_SYMBOL(vmap); |
1da177e4 | 350 | |
b3bdda02 | 351 | void vunmap(const void *addr) |
1da177e4 LT |
352 | { |
353 | BUG(); | |
354 | } | |
b5073173 | 355 | EXPORT_SYMBOL(vunmap); |
1da177e4 | 356 | |
1eeb66a1 CH |
357 | /* |
358 | * Implement a stub for vmalloc_sync_all() if the architecture chose not to | |
359 | * have one. | |
360 | */ | |
361 | void __attribute__((weak)) vmalloc_sync_all(void) | |
362 | { | |
363 | } | |
364 | ||
b5073173 PM |
365 | int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, |
366 | struct page *page) | |
367 | { | |
368 | return -EINVAL; | |
369 | } | |
370 | EXPORT_SYMBOL(vm_insert_page); | |
371 | ||
1da177e4 LT |
372 | /* |
373 | * sys_brk() for the most part doesn't need the global kernel | |
374 | * lock, except when an application is doing something nasty | |
375 | * like trying to un-brk an area that has already been mapped | |
376 | * to a regular file. in this case, the unmapping will need | |
377 | * to invoke file system routines that need the global lock. | |
378 | */ | |
379 | asmlinkage unsigned long sys_brk(unsigned long brk) | |
380 | { | |
381 | struct mm_struct *mm = current->mm; | |
382 | ||
383 | if (brk < mm->start_brk || brk > mm->context.end_brk) | |
384 | return mm->brk; | |
385 | ||
386 | if (mm->brk == brk) | |
387 | return mm->brk; | |
388 | ||
389 | /* | |
390 | * Always allow shrinking brk | |
391 | */ | |
392 | if (brk <= mm->brk) { | |
393 | mm->brk = brk; | |
394 | return brk; | |
395 | } | |
396 | ||
397 | /* | |
398 | * Ok, looks good - let it rip. | |
399 | */ | |
400 | return mm->brk = brk; | |
401 | } | |
402 | ||
403 | #ifdef DEBUG | |
404 | static void show_process_blocks(void) | |
405 | { | |
406 | struct vm_list_struct *vml; | |
407 | ||
408 | printk("Process blocks %d:", current->pid); | |
409 | ||
410 | for (vml = ¤t->mm->context.vmlist; vml; vml = vml->next) { | |
411 | printk(" %p: %p", vml, vml->vma); | |
412 | if (vml->vma) | |
413 | printk(" (%d @%lx #%d)", | |
414 | kobjsize((void *) vml->vma->vm_start), | |
415 | vml->vma->vm_start, | |
416 | atomic_read(&vml->vma->vm_usage)); | |
417 | printk(vml->next ? " ->" : ".\n"); | |
418 | } | |
419 | } | |
420 | #endif /* DEBUG */ | |
421 | ||
3034097a DH |
422 | /* |
423 | * add a VMA into a process's mm_struct in the appropriate place in the list | |
424 | * - should be called with mm->mmap_sem held writelocked | |
425 | */ | |
426 | static void add_vma_to_mm(struct mm_struct *mm, struct vm_list_struct *vml) | |
427 | { | |
428 | struct vm_list_struct **ppv; | |
429 | ||
430 | for (ppv = ¤t->mm->context.vmlist; *ppv; ppv = &(*ppv)->next) | |
431 | if ((*ppv)->vma->vm_start > vml->vma->vm_start) | |
432 | break; | |
433 | ||
434 | vml->next = *ppv; | |
435 | *ppv = vml; | |
436 | } | |
437 | ||
438 | /* | |
439 | * look up the first VMA in which addr resides, NULL if none | |
440 | * - should be called with mm->mmap_sem at least held readlocked | |
441 | */ | |
442 | struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) | |
443 | { | |
444 | struct vm_list_struct *loop, *vml; | |
445 | ||
446 | /* search the vm_start ordered list */ | |
447 | vml = NULL; | |
448 | for (loop = mm->context.vmlist; loop; loop = loop->next) { | |
449 | if (loop->vma->vm_start > addr) | |
450 | break; | |
451 | vml = loop; | |
452 | } | |
453 | ||
454 | if (vml && vml->vma->vm_end > addr) | |
455 | return vml->vma; | |
456 | ||
457 | return NULL; | |
458 | } | |
459 | EXPORT_SYMBOL(find_vma); | |
460 | ||
930e652a DH |
461 | /* |
462 | * find a VMA | |
463 | * - we don't extend stack VMAs under NOMMU conditions | |
464 | */ | |
465 | struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr) | |
466 | { | |
467 | return find_vma(mm, addr); | |
468 | } | |
469 | ||
57c8f63e GU |
470 | int expand_stack(struct vm_area_struct *vma, unsigned long address) |
471 | { | |
472 | return -ENOMEM; | |
473 | } | |
474 | ||
6fa5f80b DH |
475 | /* |
476 | * look up the first VMA exactly that exactly matches addr | |
477 | * - should be called with mm->mmap_sem at least held readlocked | |
478 | */ | |
479 | static inline struct vm_area_struct *find_vma_exact(struct mm_struct *mm, | |
480 | unsigned long addr) | |
481 | { | |
482 | struct vm_list_struct *vml; | |
483 | ||
484 | /* search the vm_start ordered list */ | |
485 | for (vml = mm->context.vmlist; vml; vml = vml->next) { | |
486 | if (vml->vma->vm_start == addr) | |
487 | return vml->vma; | |
488 | if (vml->vma->vm_start > addr) | |
489 | break; | |
490 | } | |
491 | ||
492 | return NULL; | |
493 | } | |
494 | ||
3034097a DH |
495 | /* |
496 | * find a VMA in the global tree | |
497 | */ | |
1da177e4 LT |
498 | static inline struct vm_area_struct *find_nommu_vma(unsigned long start) |
499 | { | |
500 | struct vm_area_struct *vma; | |
501 | struct rb_node *n = nommu_vma_tree.rb_node; | |
502 | ||
503 | while (n) { | |
504 | vma = rb_entry(n, struct vm_area_struct, vm_rb); | |
505 | ||
506 | if (start < vma->vm_start) | |
507 | n = n->rb_left; | |
508 | else if (start > vma->vm_start) | |
509 | n = n->rb_right; | |
510 | else | |
511 | return vma; | |
512 | } | |
513 | ||
514 | return NULL; | |
515 | } | |
516 | ||
3034097a DH |
517 | /* |
518 | * add a VMA in the global tree | |
519 | */ | |
1da177e4 LT |
520 | static void add_nommu_vma(struct vm_area_struct *vma) |
521 | { | |
522 | struct vm_area_struct *pvma; | |
523 | struct address_space *mapping; | |
524 | struct rb_node **p = &nommu_vma_tree.rb_node; | |
525 | struct rb_node *parent = NULL; | |
526 | ||
527 | /* add the VMA to the mapping */ | |
528 | if (vma->vm_file) { | |
529 | mapping = vma->vm_file->f_mapping; | |
530 | ||
531 | flush_dcache_mmap_lock(mapping); | |
532 | vma_prio_tree_insert(vma, &mapping->i_mmap); | |
533 | flush_dcache_mmap_unlock(mapping); | |
534 | } | |
535 | ||
536 | /* add the VMA to the master list */ | |
537 | while (*p) { | |
538 | parent = *p; | |
539 | pvma = rb_entry(parent, struct vm_area_struct, vm_rb); | |
540 | ||
541 | if (vma->vm_start < pvma->vm_start) { | |
542 | p = &(*p)->rb_left; | |
543 | } | |
544 | else if (vma->vm_start > pvma->vm_start) { | |
545 | p = &(*p)->rb_right; | |
546 | } | |
547 | else { | |
548 | /* mappings are at the same address - this can only | |
549 | * happen for shared-mem chardevs and shared file | |
550 | * mappings backed by ramfs/tmpfs */ | |
551 | BUG_ON(!(pvma->vm_flags & VM_SHARED)); | |
552 | ||
553 | if (vma < pvma) | |
554 | p = &(*p)->rb_left; | |
555 | else if (vma > pvma) | |
556 | p = &(*p)->rb_right; | |
557 | else | |
558 | BUG(); | |
559 | } | |
560 | } | |
561 | ||
562 | rb_link_node(&vma->vm_rb, parent, p); | |
563 | rb_insert_color(&vma->vm_rb, &nommu_vma_tree); | |
564 | } | |
565 | ||
3034097a DH |
566 | /* |
567 | * delete a VMA from the global list | |
568 | */ | |
1da177e4 LT |
569 | static void delete_nommu_vma(struct vm_area_struct *vma) |
570 | { | |
571 | struct address_space *mapping; | |
572 | ||
573 | /* remove the VMA from the mapping */ | |
574 | if (vma->vm_file) { | |
575 | mapping = vma->vm_file->f_mapping; | |
576 | ||
577 | flush_dcache_mmap_lock(mapping); | |
578 | vma_prio_tree_remove(vma, &mapping->i_mmap); | |
579 | flush_dcache_mmap_unlock(mapping); | |
580 | } | |
581 | ||
582 | /* remove from the master list */ | |
583 | rb_erase(&vma->vm_rb, &nommu_vma_tree); | |
584 | } | |
585 | ||
586 | /* | |
587 | * determine whether a mapping should be permitted and, if so, what sort of | |
588 | * mapping we're capable of supporting | |
589 | */ | |
590 | static int validate_mmap_request(struct file *file, | |
591 | unsigned long addr, | |
592 | unsigned long len, | |
593 | unsigned long prot, | |
594 | unsigned long flags, | |
595 | unsigned long pgoff, | |
596 | unsigned long *_capabilities) | |
597 | { | |
598 | unsigned long capabilities; | |
599 | unsigned long reqprot = prot; | |
600 | int ret; | |
601 | ||
602 | /* do the simple checks first */ | |
603 | if (flags & MAP_FIXED || addr) { | |
604 | printk(KERN_DEBUG | |
605 | "%d: Can't do fixed-address/overlay mmap of RAM\n", | |
606 | current->pid); | |
607 | return -EINVAL; | |
608 | } | |
609 | ||
610 | if ((flags & MAP_TYPE) != MAP_PRIVATE && | |
611 | (flags & MAP_TYPE) != MAP_SHARED) | |
612 | return -EINVAL; | |
613 | ||
f81cff0d | 614 | if (!len) |
1da177e4 LT |
615 | return -EINVAL; |
616 | ||
f81cff0d MF |
617 | /* Careful about overflows.. */ |
618 | len = PAGE_ALIGN(len); | |
619 | if (!len || len > TASK_SIZE) | |
620 | return -ENOMEM; | |
621 | ||
1da177e4 LT |
622 | /* offset overflow? */ |
623 | if ((pgoff + (len >> PAGE_SHIFT)) < pgoff) | |
f81cff0d | 624 | return -EOVERFLOW; |
1da177e4 LT |
625 | |
626 | if (file) { | |
627 | /* validate file mapping requests */ | |
628 | struct address_space *mapping; | |
629 | ||
630 | /* files must support mmap */ | |
631 | if (!file->f_op || !file->f_op->mmap) | |
632 | return -ENODEV; | |
633 | ||
634 | /* work out if what we've got could possibly be shared | |
635 | * - we support chardevs that provide their own "memory" | |
636 | * - we support files/blockdevs that are memory backed | |
637 | */ | |
638 | mapping = file->f_mapping; | |
639 | if (!mapping) | |
e9536ae7 | 640 | mapping = file->f_path.dentry->d_inode->i_mapping; |
1da177e4 LT |
641 | |
642 | capabilities = 0; | |
643 | if (mapping && mapping->backing_dev_info) | |
644 | capabilities = mapping->backing_dev_info->capabilities; | |
645 | ||
646 | if (!capabilities) { | |
647 | /* no explicit capabilities set, so assume some | |
648 | * defaults */ | |
e9536ae7 | 649 | switch (file->f_path.dentry->d_inode->i_mode & S_IFMT) { |
1da177e4 LT |
650 | case S_IFREG: |
651 | case S_IFBLK: | |
652 | capabilities = BDI_CAP_MAP_COPY; | |
653 | break; | |
654 | ||
655 | case S_IFCHR: | |
656 | capabilities = | |
657 | BDI_CAP_MAP_DIRECT | | |
658 | BDI_CAP_READ_MAP | | |
659 | BDI_CAP_WRITE_MAP; | |
660 | break; | |
661 | ||
662 | default: | |
663 | return -EINVAL; | |
664 | } | |
665 | } | |
666 | ||
667 | /* eliminate any capabilities that we can't support on this | |
668 | * device */ | |
669 | if (!file->f_op->get_unmapped_area) | |
670 | capabilities &= ~BDI_CAP_MAP_DIRECT; | |
671 | if (!file->f_op->read) | |
672 | capabilities &= ~BDI_CAP_MAP_COPY; | |
673 | ||
674 | if (flags & MAP_SHARED) { | |
675 | /* do checks for writing, appending and locking */ | |
676 | if ((prot & PROT_WRITE) && | |
677 | !(file->f_mode & FMODE_WRITE)) | |
678 | return -EACCES; | |
679 | ||
e9536ae7 | 680 | if (IS_APPEND(file->f_path.dentry->d_inode) && |
1da177e4 LT |
681 | (file->f_mode & FMODE_WRITE)) |
682 | return -EACCES; | |
683 | ||
e9536ae7 | 684 | if (locks_verify_locked(file->f_path.dentry->d_inode)) |
1da177e4 LT |
685 | return -EAGAIN; |
686 | ||
687 | if (!(capabilities & BDI_CAP_MAP_DIRECT)) | |
688 | return -ENODEV; | |
689 | ||
690 | if (((prot & PROT_READ) && !(capabilities & BDI_CAP_READ_MAP)) || | |
691 | ((prot & PROT_WRITE) && !(capabilities & BDI_CAP_WRITE_MAP)) || | |
692 | ((prot & PROT_EXEC) && !(capabilities & BDI_CAP_EXEC_MAP)) | |
693 | ) { | |
694 | printk("MAP_SHARED not completely supported on !MMU\n"); | |
695 | return -EINVAL; | |
696 | } | |
697 | ||
698 | /* we mustn't privatise shared mappings */ | |
699 | capabilities &= ~BDI_CAP_MAP_COPY; | |
700 | } | |
701 | else { | |
702 | /* we're going to read the file into private memory we | |
703 | * allocate */ | |
704 | if (!(capabilities & BDI_CAP_MAP_COPY)) | |
705 | return -ENODEV; | |
706 | ||
707 | /* we don't permit a private writable mapping to be | |
708 | * shared with the backing device */ | |
709 | if (prot & PROT_WRITE) | |
710 | capabilities &= ~BDI_CAP_MAP_DIRECT; | |
711 | } | |
712 | ||
713 | /* handle executable mappings and implied executable | |
714 | * mappings */ | |
e9536ae7 | 715 | if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) { |
1da177e4 LT |
716 | if (prot & PROT_EXEC) |
717 | return -EPERM; | |
718 | } | |
719 | else if ((prot & PROT_READ) && !(prot & PROT_EXEC)) { | |
720 | /* handle implication of PROT_EXEC by PROT_READ */ | |
721 | if (current->personality & READ_IMPLIES_EXEC) { | |
722 | if (capabilities & BDI_CAP_EXEC_MAP) | |
723 | prot |= PROT_EXEC; | |
724 | } | |
725 | } | |
726 | else if ((prot & PROT_READ) && | |
727 | (prot & PROT_EXEC) && | |
728 | !(capabilities & BDI_CAP_EXEC_MAP) | |
729 | ) { | |
730 | /* backing file is not executable, try to copy */ | |
731 | capabilities &= ~BDI_CAP_MAP_DIRECT; | |
732 | } | |
733 | } | |
734 | else { | |
735 | /* anonymous mappings are always memory backed and can be | |
736 | * privately mapped | |
737 | */ | |
738 | capabilities = BDI_CAP_MAP_COPY; | |
739 | ||
740 | /* handle PROT_EXEC implication by PROT_READ */ | |
741 | if ((prot & PROT_READ) && | |
742 | (current->personality & READ_IMPLIES_EXEC)) | |
743 | prot |= PROT_EXEC; | |
744 | } | |
745 | ||
746 | /* allow the security API to have its say */ | |
ed032189 | 747 | ret = security_file_mmap(file, reqprot, prot, flags, addr, 0); |
1da177e4 LT |
748 | if (ret < 0) |
749 | return ret; | |
750 | ||
751 | /* looks okay */ | |
752 | *_capabilities = capabilities; | |
753 | return 0; | |
754 | } | |
755 | ||
756 | /* | |
757 | * we've determined that we can make the mapping, now translate what we | |
758 | * now know into VMA flags | |
759 | */ | |
760 | static unsigned long determine_vm_flags(struct file *file, | |
761 | unsigned long prot, | |
762 | unsigned long flags, | |
763 | unsigned long capabilities) | |
764 | { | |
765 | unsigned long vm_flags; | |
766 | ||
767 | vm_flags = calc_vm_prot_bits(prot) | calc_vm_flag_bits(flags); | |
768 | vm_flags |= VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC; | |
769 | /* vm_flags |= mm->def_flags; */ | |
770 | ||
771 | if (!(capabilities & BDI_CAP_MAP_DIRECT)) { | |
772 | /* attempt to share read-only copies of mapped file chunks */ | |
773 | if (file && !(prot & PROT_WRITE)) | |
774 | vm_flags |= VM_MAYSHARE; | |
775 | } | |
776 | else { | |
777 | /* overlay a shareable mapping on the backing device or inode | |
778 | * if possible - used for chardevs, ramfs/tmpfs/shmfs and | |
779 | * romfs/cramfs */ | |
780 | if (flags & MAP_SHARED) | |
781 | vm_flags |= VM_MAYSHARE | VM_SHARED; | |
782 | else if ((((vm_flags & capabilities) ^ vm_flags) & BDI_CAP_VMFLAGS) == 0) | |
783 | vm_flags |= VM_MAYSHARE; | |
784 | } | |
785 | ||
786 | /* refuse to let anyone share private mappings with this process if | |
787 | * it's being traced - otherwise breakpoints set in it may interfere | |
788 | * with another untraced process | |
789 | */ | |
fa8e26cc | 790 | if ((flags & MAP_PRIVATE) && tracehook_expect_breakpoints(current)) |
1da177e4 LT |
791 | vm_flags &= ~VM_MAYSHARE; |
792 | ||
793 | return vm_flags; | |
794 | } | |
795 | ||
796 | /* | |
797 | * set up a shared mapping on a file | |
798 | */ | |
799 | static int do_mmap_shared_file(struct vm_area_struct *vma, unsigned long len) | |
800 | { | |
801 | int ret; | |
802 | ||
803 | ret = vma->vm_file->f_op->mmap(vma->vm_file, vma); | |
804 | if (ret != -ENOSYS) | |
805 | return ret; | |
806 | ||
807 | /* getting an ENOSYS error indicates that direct mmap isn't | |
808 | * possible (as opposed to tried but failed) so we'll fall | |
809 | * through to making a private copy of the data and mapping | |
810 | * that if we can */ | |
811 | return -ENODEV; | |
812 | } | |
813 | ||
814 | /* | |
815 | * set up a private mapping or an anonymous shared mapping | |
816 | */ | |
817 | static int do_mmap_private(struct vm_area_struct *vma, unsigned long len) | |
818 | { | |
819 | void *base; | |
820 | int ret; | |
821 | ||
822 | /* invoke the file's mapping function so that it can keep track of | |
823 | * shared mappings on devices or memory | |
824 | * - VM_MAYSHARE will be set if it may attempt to share | |
825 | */ | |
826 | if (vma->vm_file) { | |
827 | ret = vma->vm_file->f_op->mmap(vma->vm_file, vma); | |
828 | if (ret != -ENOSYS) { | |
829 | /* shouldn't return success if we're not sharing */ | |
830 | BUG_ON(ret == 0 && !(vma->vm_flags & VM_MAYSHARE)); | |
831 | return ret; /* success or a real error */ | |
832 | } | |
833 | ||
834 | /* getting an ENOSYS error indicates that direct mmap isn't | |
835 | * possible (as opposed to tried but failed) so we'll try to | |
836 | * make a private copy of the data and map that instead */ | |
837 | } | |
838 | ||
839 | /* allocate some memory to hold the mapping | |
840 | * - note that this may not return a page-aligned address if the object | |
841 | * we're allocating is smaller than a page | |
842 | */ | |
84097518 | 843 | base = kmalloc(len, GFP_KERNEL|__GFP_COMP); |
1da177e4 LT |
844 | if (!base) |
845 | goto enomem; | |
846 | ||
847 | vma->vm_start = (unsigned long) base; | |
848 | vma->vm_end = vma->vm_start + len; | |
849 | vma->vm_flags |= VM_MAPPED_COPY; | |
850 | ||
851 | #ifdef WARN_ON_SLACK | |
852 | if (len + WARN_ON_SLACK <= kobjsize(result)) | |
853 | printk("Allocation of %lu bytes from process %d has %lu bytes of slack\n", | |
854 | len, current->pid, kobjsize(result) - len); | |
855 | #endif | |
856 | ||
857 | if (vma->vm_file) { | |
858 | /* read the contents of a file into the copy */ | |
859 | mm_segment_t old_fs; | |
860 | loff_t fpos; | |
861 | ||
862 | fpos = vma->vm_pgoff; | |
863 | fpos <<= PAGE_SHIFT; | |
864 | ||
865 | old_fs = get_fs(); | |
866 | set_fs(KERNEL_DS); | |
867 | ret = vma->vm_file->f_op->read(vma->vm_file, base, len, &fpos); | |
868 | set_fs(old_fs); | |
869 | ||
870 | if (ret < 0) | |
871 | goto error_free; | |
872 | ||
873 | /* clear the last little bit */ | |
874 | if (ret < len) | |
875 | memset(base + ret, 0, len - ret); | |
876 | ||
877 | } else { | |
878 | /* if it's an anonymous mapping, then just clear it */ | |
879 | memset(base, 0, len); | |
880 | } | |
881 | ||
882 | return 0; | |
883 | ||
884 | error_free: | |
885 | kfree(base); | |
886 | vma->vm_start = 0; | |
887 | return ret; | |
888 | ||
889 | enomem: | |
890 | printk("Allocation of length %lu from process %d failed\n", | |
891 | len, current->pid); | |
892 | show_free_areas(); | |
893 | return -ENOMEM; | |
894 | } | |
895 | ||
896 | /* | |
897 | * handle mapping creation for uClinux | |
898 | */ | |
899 | unsigned long do_mmap_pgoff(struct file *file, | |
900 | unsigned long addr, | |
901 | unsigned long len, | |
902 | unsigned long prot, | |
903 | unsigned long flags, | |
904 | unsigned long pgoff) | |
905 | { | |
906 | struct vm_list_struct *vml = NULL; | |
907 | struct vm_area_struct *vma = NULL; | |
908 | struct rb_node *rb; | |
909 | unsigned long capabilities, vm_flags; | |
910 | void *result; | |
911 | int ret; | |
912 | ||
7cd94146 EP |
913 | if (!(flags & MAP_FIXED)) |
914 | addr = round_hint_to_min(addr); | |
915 | ||
1da177e4 LT |
916 | /* decide whether we should attempt the mapping, and if so what sort of |
917 | * mapping */ | |
918 | ret = validate_mmap_request(file, addr, len, prot, flags, pgoff, | |
919 | &capabilities); | |
920 | if (ret < 0) | |
921 | return ret; | |
922 | ||
923 | /* we've determined that we can make the mapping, now translate what we | |
924 | * now know into VMA flags */ | |
925 | vm_flags = determine_vm_flags(file, prot, flags, capabilities); | |
926 | ||
927 | /* we're going to need to record the mapping if it works */ | |
4668edc3 | 928 | vml = kzalloc(sizeof(struct vm_list_struct), GFP_KERNEL); |
1da177e4 LT |
929 | if (!vml) |
930 | goto error_getting_vml; | |
1da177e4 LT |
931 | |
932 | down_write(&nommu_vma_sem); | |
933 | ||
934 | /* if we want to share, we need to check for VMAs created by other | |
935 | * mmap() calls that overlap with our proposed mapping | |
936 | * - we can only share with an exact match on most regular files | |
937 | * - shared mappings on character devices and memory backed files are | |
938 | * permitted to overlap inexactly as far as we are concerned for in | |
939 | * these cases, sharing is handled in the driver or filesystem rather | |
940 | * than here | |
941 | */ | |
942 | if (vm_flags & VM_MAYSHARE) { | |
943 | unsigned long pglen = (len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
944 | unsigned long vmpglen; | |
945 | ||
165b2392 DH |
946 | /* suppress VMA sharing for shared regions */ |
947 | if (vm_flags & VM_SHARED && | |
948 | capabilities & BDI_CAP_MAP_DIRECT) | |
949 | goto dont_share_VMAs; | |
950 | ||
1da177e4 LT |
951 | for (rb = rb_first(&nommu_vma_tree); rb; rb = rb_next(rb)) { |
952 | vma = rb_entry(rb, struct vm_area_struct, vm_rb); | |
953 | ||
954 | if (!(vma->vm_flags & VM_MAYSHARE)) | |
955 | continue; | |
956 | ||
957 | /* search for overlapping mappings on the same file */ | |
e9536ae7 | 958 | if (vma->vm_file->f_path.dentry->d_inode != file->f_path.dentry->d_inode) |
1da177e4 LT |
959 | continue; |
960 | ||
961 | if (vma->vm_pgoff >= pgoff + pglen) | |
962 | continue; | |
963 | ||
964 | vmpglen = vma->vm_end - vma->vm_start + PAGE_SIZE - 1; | |
965 | vmpglen >>= PAGE_SHIFT; | |
966 | if (pgoff >= vma->vm_pgoff + vmpglen) | |
967 | continue; | |
968 | ||
969 | /* handle inexactly overlapping matches between mappings */ | |
970 | if (vma->vm_pgoff != pgoff || vmpglen != pglen) { | |
971 | if (!(capabilities & BDI_CAP_MAP_DIRECT)) | |
972 | goto sharing_violation; | |
973 | continue; | |
974 | } | |
975 | ||
976 | /* we've found a VMA we can share */ | |
977 | atomic_inc(&vma->vm_usage); | |
978 | ||
979 | vml->vma = vma; | |
980 | result = (void *) vma->vm_start; | |
981 | goto shared; | |
982 | } | |
983 | ||
165b2392 | 984 | dont_share_VMAs: |
1da177e4 LT |
985 | vma = NULL; |
986 | ||
987 | /* obtain the address at which to make a shared mapping | |
988 | * - this is the hook for quasi-memory character devices to | |
989 | * tell us the location of a shared mapping | |
990 | */ | |
991 | if (file && file->f_op->get_unmapped_area) { | |
992 | addr = file->f_op->get_unmapped_area(file, addr, len, | |
993 | pgoff, flags); | |
994 | if (IS_ERR((void *) addr)) { | |
995 | ret = addr; | |
996 | if (ret != (unsigned long) -ENOSYS) | |
997 | goto error; | |
998 | ||
999 | /* the driver refused to tell us where to site | |
1000 | * the mapping so we'll have to attempt to copy | |
1001 | * it */ | |
1002 | ret = (unsigned long) -ENODEV; | |
1003 | if (!(capabilities & BDI_CAP_MAP_COPY)) | |
1004 | goto error; | |
1005 | ||
1006 | capabilities &= ~BDI_CAP_MAP_DIRECT; | |
1007 | } | |
1008 | } | |
1009 | } | |
1010 | ||
1011 | /* we're going to need a VMA struct as well */ | |
4668edc3 | 1012 | vma = kzalloc(sizeof(struct vm_area_struct), GFP_KERNEL); |
1da177e4 LT |
1013 | if (!vma) |
1014 | goto error_getting_vma; | |
1015 | ||
1da177e4 LT |
1016 | INIT_LIST_HEAD(&vma->anon_vma_node); |
1017 | atomic_set(&vma->vm_usage, 1); | |
925d1c40 | 1018 | if (file) { |
1da177e4 | 1019 | get_file(file); |
925d1c40 MH |
1020 | if (vm_flags & VM_EXECUTABLE) { |
1021 | added_exe_file_vma(current->mm); | |
1022 | vma->vm_mm = current->mm; | |
1023 | } | |
1024 | } | |
1da177e4 LT |
1025 | vma->vm_file = file; |
1026 | vma->vm_flags = vm_flags; | |
1027 | vma->vm_start = addr; | |
1028 | vma->vm_end = addr + len; | |
1029 | vma->vm_pgoff = pgoff; | |
1030 | ||
1031 | vml->vma = vma; | |
1032 | ||
1033 | /* set up the mapping */ | |
1034 | if (file && vma->vm_flags & VM_SHARED) | |
1035 | ret = do_mmap_shared_file(vma, len); | |
1036 | else | |
1037 | ret = do_mmap_private(vma, len); | |
1038 | if (ret < 0) | |
1039 | goto error; | |
1040 | ||
1041 | /* okay... we have a mapping; now we have to register it */ | |
1042 | result = (void *) vma->vm_start; | |
1043 | ||
1da177e4 LT |
1044 | current->mm->total_vm += len >> PAGE_SHIFT; |
1045 | ||
1046 | add_nommu_vma(vma); | |
1047 | ||
1048 | shared: | |
3034097a | 1049 | add_vma_to_mm(current->mm, vml); |
1da177e4 LT |
1050 | |
1051 | up_write(&nommu_vma_sem); | |
1052 | ||
1053 | if (prot & PROT_EXEC) | |
1054 | flush_icache_range((unsigned long) result, | |
1055 | (unsigned long) result + len); | |
1056 | ||
1057 | #ifdef DEBUG | |
1058 | printk("do_mmap:\n"); | |
1059 | show_process_blocks(); | |
1060 | #endif | |
1061 | ||
1062 | return (unsigned long) result; | |
1063 | ||
1064 | error: | |
1065 | up_write(&nommu_vma_sem); | |
1066 | kfree(vml); | |
1067 | if (vma) { | |
925d1c40 | 1068 | if (vma->vm_file) { |
3fcd03e0 | 1069 | fput(vma->vm_file); |
925d1c40 MH |
1070 | if (vma->vm_flags & VM_EXECUTABLE) |
1071 | removed_exe_file_vma(vma->vm_mm); | |
1072 | } | |
1da177e4 LT |
1073 | kfree(vma); |
1074 | } | |
1075 | return ret; | |
1076 | ||
1077 | sharing_violation: | |
1078 | up_write(&nommu_vma_sem); | |
1079 | printk("Attempt to share mismatched mappings\n"); | |
1080 | kfree(vml); | |
1081 | return -EINVAL; | |
1082 | ||
1083 | error_getting_vma: | |
1084 | up_write(&nommu_vma_sem); | |
1085 | kfree(vml); | |
66aa2b4b | 1086 | printk("Allocation of vma for %lu byte allocation from process %d failed\n", |
1da177e4 LT |
1087 | len, current->pid); |
1088 | show_free_areas(); | |
1089 | return -ENOMEM; | |
1090 | ||
1091 | error_getting_vml: | |
1092 | printk("Allocation of vml for %lu byte allocation from process %d failed\n", | |
1093 | len, current->pid); | |
1094 | show_free_areas(); | |
1095 | return -ENOMEM; | |
1096 | } | |
b5073173 | 1097 | EXPORT_SYMBOL(do_mmap_pgoff); |
1da177e4 LT |
1098 | |
1099 | /* | |
1100 | * handle mapping disposal for uClinux | |
1101 | */ | |
925d1c40 | 1102 | static void put_vma(struct mm_struct *mm, struct vm_area_struct *vma) |
1da177e4 LT |
1103 | { |
1104 | if (vma) { | |
1105 | down_write(&nommu_vma_sem); | |
1106 | ||
1107 | if (atomic_dec_and_test(&vma->vm_usage)) { | |
1108 | delete_nommu_vma(vma); | |
1109 | ||
1110 | if (vma->vm_ops && vma->vm_ops->close) | |
1111 | vma->vm_ops->close(vma); | |
1112 | ||
1113 | /* IO memory and memory shared directly out of the pagecache from | |
1114 | * ramfs/tmpfs mustn't be released here */ | |
41836382 | 1115 | if (vma->vm_flags & VM_MAPPED_COPY) |
1da177e4 | 1116 | kfree((void *) vma->vm_start); |
1da177e4 | 1117 | |
925d1c40 | 1118 | if (vma->vm_file) { |
1da177e4 | 1119 | fput(vma->vm_file); |
925d1c40 MH |
1120 | if (vma->vm_flags & VM_EXECUTABLE) |
1121 | removed_exe_file_vma(mm); | |
1122 | } | |
1da177e4 LT |
1123 | kfree(vma); |
1124 | } | |
1125 | ||
1126 | up_write(&nommu_vma_sem); | |
1127 | } | |
1128 | } | |
1129 | ||
3034097a DH |
1130 | /* |
1131 | * release a mapping | |
1132 | * - under NOMMU conditions the parameters must match exactly to the mapping to | |
1133 | * be removed | |
1134 | */ | |
1da177e4 LT |
1135 | int do_munmap(struct mm_struct *mm, unsigned long addr, size_t len) |
1136 | { | |
1137 | struct vm_list_struct *vml, **parent; | |
1138 | unsigned long end = addr + len; | |
1139 | ||
1140 | #ifdef DEBUG | |
1141 | printk("do_munmap:\n"); | |
1142 | #endif | |
1143 | ||
3034097a DH |
1144 | for (parent = &mm->context.vmlist; *parent; parent = &(*parent)->next) { |
1145 | if ((*parent)->vma->vm_start > addr) | |
1146 | break; | |
1da177e4 | 1147 | if ((*parent)->vma->vm_start == addr && |
66aa2b4b | 1148 | ((len == 0) || ((*parent)->vma->vm_end == end))) |
1da177e4 | 1149 | goto found; |
3034097a | 1150 | } |
1da177e4 LT |
1151 | |
1152 | printk("munmap of non-mmaped memory by process %d (%s): %p\n", | |
1153 | current->pid, current->comm, (void *) addr); | |
1154 | return -EINVAL; | |
1155 | ||
1156 | found: | |
1157 | vml = *parent; | |
1158 | ||
925d1c40 | 1159 | put_vma(mm, vml->vma); |
1da177e4 LT |
1160 | |
1161 | *parent = vml->next; | |
1da177e4 | 1162 | kfree(vml); |
365e9c87 HD |
1163 | |
1164 | update_hiwater_vm(mm); | |
1da177e4 LT |
1165 | mm->total_vm -= len >> PAGE_SHIFT; |
1166 | ||
1167 | #ifdef DEBUG | |
1168 | show_process_blocks(); | |
1169 | #endif | |
1170 | ||
1171 | return 0; | |
1172 | } | |
b5073173 | 1173 | EXPORT_SYMBOL(do_munmap); |
1da177e4 | 1174 | |
3034097a DH |
1175 | asmlinkage long sys_munmap(unsigned long addr, size_t len) |
1176 | { | |
1177 | int ret; | |
1178 | struct mm_struct *mm = current->mm; | |
1179 | ||
1180 | down_write(&mm->mmap_sem); | |
1181 | ret = do_munmap(mm, addr, len); | |
1182 | up_write(&mm->mmap_sem); | |
1183 | return ret; | |
1184 | } | |
1185 | ||
1186 | /* | |
1187 | * Release all mappings | |
1188 | */ | |
1da177e4 LT |
1189 | void exit_mmap(struct mm_struct * mm) |
1190 | { | |
1191 | struct vm_list_struct *tmp; | |
1192 | ||
1193 | if (mm) { | |
1194 | #ifdef DEBUG | |
1195 | printk("Exit_mmap:\n"); | |
1196 | #endif | |
1197 | ||
1198 | mm->total_vm = 0; | |
1199 | ||
1200 | while ((tmp = mm->context.vmlist)) { | |
1201 | mm->context.vmlist = tmp->next; | |
925d1c40 | 1202 | put_vma(mm, tmp->vma); |
1da177e4 LT |
1203 | kfree(tmp); |
1204 | } | |
1205 | ||
1206 | #ifdef DEBUG | |
1207 | show_process_blocks(); | |
1208 | #endif | |
1209 | } | |
1210 | } | |
1211 | ||
1da177e4 LT |
1212 | unsigned long do_brk(unsigned long addr, unsigned long len) |
1213 | { | |
1214 | return -ENOMEM; | |
1215 | } | |
1216 | ||
1217 | /* | |
6fa5f80b DH |
1218 | * expand (or shrink) an existing mapping, potentially moving it at the same |
1219 | * time (controlled by the MREMAP_MAYMOVE flag and available VM space) | |
1da177e4 | 1220 | * |
6fa5f80b DH |
1221 | * under NOMMU conditions, we only permit changing a mapping's size, and only |
1222 | * as long as it stays within the hole allocated by the kmalloc() call in | |
1223 | * do_mmap_pgoff() and the block is not shareable | |
1da177e4 | 1224 | * |
6fa5f80b | 1225 | * MREMAP_FIXED is not supported under NOMMU conditions |
1da177e4 LT |
1226 | */ |
1227 | unsigned long do_mremap(unsigned long addr, | |
1228 | unsigned long old_len, unsigned long new_len, | |
1229 | unsigned long flags, unsigned long new_addr) | |
1230 | { | |
6fa5f80b | 1231 | struct vm_area_struct *vma; |
1da177e4 LT |
1232 | |
1233 | /* insanity checks first */ | |
1234 | if (new_len == 0) | |
1235 | return (unsigned long) -EINVAL; | |
1236 | ||
1237 | if (flags & MREMAP_FIXED && new_addr != addr) | |
1238 | return (unsigned long) -EINVAL; | |
1239 | ||
6fa5f80b DH |
1240 | vma = find_vma_exact(current->mm, addr); |
1241 | if (!vma) | |
1242 | return (unsigned long) -EINVAL; | |
1da177e4 | 1243 | |
6fa5f80b | 1244 | if (vma->vm_end != vma->vm_start + old_len) |
1da177e4 LT |
1245 | return (unsigned long) -EFAULT; |
1246 | ||
6fa5f80b | 1247 | if (vma->vm_flags & VM_MAYSHARE) |
1da177e4 LT |
1248 | return (unsigned long) -EPERM; |
1249 | ||
1250 | if (new_len > kobjsize((void *) addr)) | |
1251 | return (unsigned long) -ENOMEM; | |
1252 | ||
1253 | /* all checks complete - do it */ | |
6fa5f80b | 1254 | vma->vm_end = vma->vm_start + new_len; |
1da177e4 | 1255 | |
6fa5f80b DH |
1256 | return vma->vm_start; |
1257 | } | |
b5073173 | 1258 | EXPORT_SYMBOL(do_mremap); |
6fa5f80b DH |
1259 | |
1260 | asmlinkage unsigned long sys_mremap(unsigned long addr, | |
1261 | unsigned long old_len, unsigned long new_len, | |
1262 | unsigned long flags, unsigned long new_addr) | |
1263 | { | |
1264 | unsigned long ret; | |
1265 | ||
1266 | down_write(¤t->mm->mmap_sem); | |
1267 | ret = do_mremap(addr, old_len, new_len, flags, new_addr); | |
1268 | up_write(¤t->mm->mmap_sem); | |
1269 | return ret; | |
1da177e4 LT |
1270 | } |
1271 | ||
6aab341e | 1272 | struct page *follow_page(struct vm_area_struct *vma, unsigned long address, |
deceb6cd | 1273 | unsigned int foll_flags) |
1da177e4 LT |
1274 | { |
1275 | return NULL; | |
1276 | } | |
1277 | ||
1da177e4 LT |
1278 | int remap_pfn_range(struct vm_area_struct *vma, unsigned long from, |
1279 | unsigned long to, unsigned long size, pgprot_t prot) | |
1280 | { | |
66aa2b4b GU |
1281 | vma->vm_start = vma->vm_pgoff << PAGE_SHIFT; |
1282 | return 0; | |
1da177e4 | 1283 | } |
22c4af40 | 1284 | EXPORT_SYMBOL(remap_pfn_range); |
1da177e4 | 1285 | |
f905bc44 PM |
1286 | int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, |
1287 | unsigned long pgoff) | |
1288 | { | |
1289 | unsigned int size = vma->vm_end - vma->vm_start; | |
1290 | ||
1291 | if (!(vma->vm_flags & VM_USERMAP)) | |
1292 | return -EINVAL; | |
1293 | ||
1294 | vma->vm_start = (unsigned long)(addr + (pgoff << PAGE_SHIFT)); | |
1295 | vma->vm_end = vma->vm_start + size; | |
1296 | ||
1297 | return 0; | |
1298 | } | |
1299 | EXPORT_SYMBOL(remap_vmalloc_range); | |
1300 | ||
1da177e4 LT |
1301 | void swap_unplug_io_fn(struct backing_dev_info *bdi, struct page *page) |
1302 | { | |
1303 | } | |
1304 | ||
1305 | unsigned long arch_get_unmapped_area(struct file *file, unsigned long addr, | |
1306 | unsigned long len, unsigned long pgoff, unsigned long flags) | |
1307 | { | |
1308 | return -ENOMEM; | |
1309 | } | |
1310 | ||
1363c3cd | 1311 | void arch_unmap_area(struct mm_struct *mm, unsigned long addr) |
1da177e4 LT |
1312 | { |
1313 | } | |
1314 | ||
1da177e4 LT |
1315 | void unmap_mapping_range(struct address_space *mapping, |
1316 | loff_t const holebegin, loff_t const holelen, | |
1317 | int even_cows) | |
1318 | { | |
1319 | } | |
22c4af40 | 1320 | EXPORT_SYMBOL(unmap_mapping_range); |
1da177e4 | 1321 | |
d56e03cd DH |
1322 | /* |
1323 | * ask for an unmapped area at which to create a mapping on a file | |
1324 | */ | |
1325 | unsigned long get_unmapped_area(struct file *file, unsigned long addr, | |
1326 | unsigned long len, unsigned long pgoff, | |
1327 | unsigned long flags) | |
1328 | { | |
1329 | unsigned long (*get_area)(struct file *, unsigned long, unsigned long, | |
1330 | unsigned long, unsigned long); | |
1331 | ||
1332 | get_area = current->mm->get_unmapped_area; | |
1333 | if (file && file->f_op && file->f_op->get_unmapped_area) | |
1334 | get_area = file->f_op->get_unmapped_area; | |
1335 | ||
1336 | if (!get_area) | |
1337 | return -ENOSYS; | |
1338 | ||
1339 | return get_area(file, addr, len, pgoff, flags); | |
1340 | } | |
d56e03cd DH |
1341 | EXPORT_SYMBOL(get_unmapped_area); |
1342 | ||
1da177e4 LT |
1343 | /* |
1344 | * Check that a process has enough memory to allocate a new virtual | |
1345 | * mapping. 0 means there is enough memory for the allocation to | |
1346 | * succeed and -ENOMEM implies there is not. | |
1347 | * | |
1348 | * We currently support three overcommit policies, which are set via the | |
1349 | * vm.overcommit_memory sysctl. See Documentation/vm/overcommit-accounting | |
1350 | * | |
1351 | * Strict overcommit modes added 2002 Feb 26 by Alan Cox. | |
1352 | * Additional code 2002 Jul 20 by Robert Love. | |
1353 | * | |
1354 | * cap_sys_admin is 1 if the process has admin privileges, 0 otherwise. | |
1355 | * | |
1356 | * Note this is a helper function intended to be used by LSMs which | |
1357 | * wish to use this logic. | |
1358 | */ | |
34b4e4aa | 1359 | int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin) |
1da177e4 LT |
1360 | { |
1361 | unsigned long free, allowed; | |
1362 | ||
1363 | vm_acct_memory(pages); | |
1364 | ||
1365 | /* | |
1366 | * Sometimes we want to use more memory than we have | |
1367 | */ | |
1368 | if (sysctl_overcommit_memory == OVERCOMMIT_ALWAYS) | |
1369 | return 0; | |
1370 | ||
1371 | if (sysctl_overcommit_memory == OVERCOMMIT_GUESS) { | |
1372 | unsigned long n; | |
1373 | ||
347ce434 | 1374 | free = global_page_state(NR_FILE_PAGES); |
1da177e4 LT |
1375 | free += nr_swap_pages; |
1376 | ||
1377 | /* | |
1378 | * Any slabs which are created with the | |
1379 | * SLAB_RECLAIM_ACCOUNT flag claim to have contents | |
1380 | * which are reclaimable, under pressure. The dentry | |
1381 | * cache and most inode caches should fall into this | |
1382 | */ | |
972d1a7b | 1383 | free += global_page_state(NR_SLAB_RECLAIMABLE); |
1da177e4 LT |
1384 | |
1385 | /* | |
1386 | * Leave the last 3% for root | |
1387 | */ | |
1388 | if (!cap_sys_admin) | |
1389 | free -= free / 32; | |
1390 | ||
1391 | if (free > pages) | |
1392 | return 0; | |
1393 | ||
1394 | /* | |
1395 | * nr_free_pages() is very expensive on large systems, | |
1396 | * only call if we're about to fail. | |
1397 | */ | |
1398 | n = nr_free_pages(); | |
d5ddc79b HA |
1399 | |
1400 | /* | |
1401 | * Leave reserved pages. The pages are not for anonymous pages. | |
1402 | */ | |
1403 | if (n <= totalreserve_pages) | |
1404 | goto error; | |
1405 | else | |
1406 | n -= totalreserve_pages; | |
1407 | ||
1408 | /* | |
1409 | * Leave the last 3% for root | |
1410 | */ | |
1da177e4 LT |
1411 | if (!cap_sys_admin) |
1412 | n -= n / 32; | |
1413 | free += n; | |
1414 | ||
1415 | if (free > pages) | |
1416 | return 0; | |
d5ddc79b HA |
1417 | |
1418 | goto error; | |
1da177e4 LT |
1419 | } |
1420 | ||
1421 | allowed = totalram_pages * sysctl_overcommit_ratio / 100; | |
1422 | /* | |
1423 | * Leave the last 3% for root | |
1424 | */ | |
1425 | if (!cap_sys_admin) | |
1426 | allowed -= allowed / 32; | |
1427 | allowed += total_swap_pages; | |
1428 | ||
1429 | /* Don't let a single process grow too big: | |
1430 | leave 3% of the size of this process for other processes */ | |
731572d3 AC |
1431 | if (mm) |
1432 | allowed -= mm->total_vm / 32; | |
1da177e4 | 1433 | |
2f60f8d3 SD |
1434 | /* |
1435 | * cast `allowed' as a signed long because vm_committed_space | |
1436 | * sometimes has a negative value | |
1437 | */ | |
80119ef5 | 1438 | if (atomic_long_read(&vm_committed_space) < (long)allowed) |
1da177e4 | 1439 | return 0; |
d5ddc79b | 1440 | error: |
1da177e4 LT |
1441 | vm_unacct_memory(pages); |
1442 | ||
1443 | return -ENOMEM; | |
1444 | } | |
1445 | ||
1446 | int in_gate_area_no_task(unsigned long addr) | |
1447 | { | |
1448 | return 0; | |
1449 | } | |
b0e15190 | 1450 | |
d0217ac0 | 1451 | int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
b0e15190 DH |
1452 | { |
1453 | BUG(); | |
d0217ac0 | 1454 | return 0; |
b0e15190 | 1455 | } |
b5073173 | 1456 | EXPORT_SYMBOL(filemap_fault); |
0ec76a11 DH |
1457 | |
1458 | /* | |
1459 | * Access another process' address space. | |
1460 | * - source/target buffer must be kernel space | |
1461 | */ | |
1462 | int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write) | |
1463 | { | |
0ec76a11 DH |
1464 | struct vm_area_struct *vma; |
1465 | struct mm_struct *mm; | |
1466 | ||
1467 | if (addr + len < addr) | |
1468 | return 0; | |
1469 | ||
1470 | mm = get_task_mm(tsk); | |
1471 | if (!mm) | |
1472 | return 0; | |
1473 | ||
1474 | down_read(&mm->mmap_sem); | |
1475 | ||
1476 | /* the access must start within one of the target process's mappings */ | |
0159b141 DH |
1477 | vma = find_vma(mm, addr); |
1478 | if (vma) { | |
0ec76a11 DH |
1479 | /* don't overrun this mapping */ |
1480 | if (addr + len >= vma->vm_end) | |
1481 | len = vma->vm_end - addr; | |
1482 | ||
1483 | /* only read or write mappings where it is permitted */ | |
d00c7b99 | 1484 | if (write && vma->vm_flags & VM_MAYWRITE) |
0ec76a11 | 1485 | len -= copy_to_user((void *) addr, buf, len); |
d00c7b99 | 1486 | else if (!write && vma->vm_flags & VM_MAYREAD) |
0ec76a11 DH |
1487 | len -= copy_from_user(buf, (void *) addr, len); |
1488 | else | |
1489 | len = 0; | |
1490 | } else { | |
1491 | len = 0; | |
1492 | } | |
1493 | ||
1494 | up_read(&mm->mmap_sem); | |
1495 | mmput(mm); | |
1496 | return len; | |
1497 | } |