Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/mm/nommu.c | |
3 | * | |
4 | * Replacement code for mm functions to support CPU's that don't | |
5 | * have any form of memory management unit (thus no virtual memory). | |
6 | * | |
7 | * See Documentation/nommu-mmap.txt | |
8 | * | |
8feae131 | 9 | * Copyright (c) 2004-2008 David Howells <dhowells@redhat.com> |
1da177e4 LT |
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> | |
eb6434d9 | 13 | * Copyright (c) 2007-2009 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> | |
8feae131 DH |
36 | #include "internal.h" |
37 | ||
38 | static inline __attribute__((format(printf, 1, 2))) | |
39 | void no_printk(const char *fmt, ...) | |
40 | { | |
41 | } | |
42 | ||
43 | #if 0 | |
44 | #define kenter(FMT, ...) \ | |
45 | printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__) | |
46 | #define kleave(FMT, ...) \ | |
47 | printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__) | |
48 | #define kdebug(FMT, ...) \ | |
49 | printk(KERN_DEBUG "xxx" FMT"yyy\n", ##__VA_ARGS__) | |
50 | #else | |
51 | #define kenter(FMT, ...) \ | |
52 | no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__) | |
53 | #define kleave(FMT, ...) \ | |
54 | no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__) | |
55 | #define kdebug(FMT, ...) \ | |
56 | no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__) | |
57 | #endif | |
1da177e4 | 58 | |
b291f000 NP |
59 | #include "internal.h" |
60 | ||
1da177e4 LT |
61 | void *high_memory; |
62 | struct page *mem_map; | |
63 | unsigned long max_mapnr; | |
64 | unsigned long num_physpages; | |
00a62ce9 | 65 | struct percpu_counter vm_committed_as; |
1da177e4 LT |
66 | int sysctl_overcommit_memory = OVERCOMMIT_GUESS; /* heuristic overcommit */ |
67 | int sysctl_overcommit_ratio = 50; /* default is 50% */ | |
68 | int sysctl_max_map_count = DEFAULT_MAX_MAP_COUNT; | |
fc4d5c29 | 69 | int sysctl_nr_trim_pages = CONFIG_NOMMU_INITIAL_TRIM_EXCESS; |
1da177e4 LT |
70 | int heap_stack_gap = 0; |
71 | ||
35f2c2f6 PM |
72 | /* amount of vm to protect from userspace access */ |
73 | unsigned long mmap_min_addr = CONFIG_DEFAULT_MMAP_MIN_ADDR; | |
74 | ||
33e5d769 | 75 | atomic_long_t mmap_pages_allocated; |
8feae131 | 76 | |
1da177e4 | 77 | EXPORT_SYMBOL(mem_map); |
6a04de6d | 78 | EXPORT_SYMBOL(num_physpages); |
1da177e4 | 79 | |
8feae131 DH |
80 | /* list of mapped, potentially shareable regions */ |
81 | static struct kmem_cache *vm_region_jar; | |
82 | struct rb_root nommu_region_tree = RB_ROOT; | |
83 | DECLARE_RWSEM(nommu_region_sem); | |
1da177e4 LT |
84 | |
85 | struct vm_operations_struct generic_file_vm_ops = { | |
86 | }; | |
87 | ||
88 | /* | |
89 | * Handle all mappings that got truncated by a "truncate()" | |
90 | * system call. | |
91 | * | |
92 | * NOTE! We have to be ready to update the memory sharing | |
93 | * between the file and the memory map for a potential last | |
94 | * incomplete page. Ugly, but necessary. | |
95 | */ | |
96 | int vmtruncate(struct inode *inode, loff_t offset) | |
97 | { | |
98 | struct address_space *mapping = inode->i_mapping; | |
99 | unsigned long limit; | |
100 | ||
101 | if (inode->i_size < offset) | |
102 | goto do_expand; | |
103 | i_size_write(inode, offset); | |
104 | ||
105 | truncate_inode_pages(mapping, offset); | |
106 | goto out_truncate; | |
107 | ||
108 | do_expand: | |
109 | limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur; | |
110 | if (limit != RLIM_INFINITY && offset > limit) | |
111 | goto out_sig; | |
112 | if (offset > inode->i_sb->s_maxbytes) | |
113 | goto out; | |
114 | i_size_write(inode, offset); | |
115 | ||
116 | out_truncate: | |
acfa4380 | 117 | if (inode->i_op->truncate) |
1da177e4 LT |
118 | inode->i_op->truncate(inode); |
119 | return 0; | |
120 | out_sig: | |
121 | send_sig(SIGXFSZ, current, 0); | |
122 | out: | |
123 | return -EFBIG; | |
124 | } | |
125 | ||
126 | EXPORT_SYMBOL(vmtruncate); | |
127 | ||
128 | /* | |
129 | * Return the total memory allocated for this pointer, not | |
130 | * just what the caller asked for. | |
131 | * | |
132 | * Doesn't have to be accurate, i.e. may have races. | |
133 | */ | |
134 | unsigned int kobjsize(const void *objp) | |
135 | { | |
136 | struct page *page; | |
137 | ||
4016a139 MH |
138 | /* |
139 | * If the object we have should not have ksize performed on it, | |
140 | * return size of 0 | |
141 | */ | |
5a1603be | 142 | if (!objp || !virt_addr_valid(objp)) |
6cfd53fc PM |
143 | return 0; |
144 | ||
145 | page = virt_to_head_page(objp); | |
6cfd53fc PM |
146 | |
147 | /* | |
148 | * If the allocator sets PageSlab, we know the pointer came from | |
149 | * kmalloc(). | |
150 | */ | |
1da177e4 LT |
151 | if (PageSlab(page)) |
152 | return ksize(objp); | |
153 | ||
ab2e83ea PM |
154 | /* |
155 | * If it's not a compound page, see if we have a matching VMA | |
156 | * region. This test is intentionally done in reverse order, | |
157 | * so if there's no VMA, we still fall through and hand back | |
158 | * PAGE_SIZE for 0-order pages. | |
159 | */ | |
160 | if (!PageCompound(page)) { | |
161 | struct vm_area_struct *vma; | |
162 | ||
163 | vma = find_vma(current->mm, (unsigned long)objp); | |
164 | if (vma) | |
165 | return vma->vm_end - vma->vm_start; | |
166 | } | |
167 | ||
6cfd53fc PM |
168 | /* |
169 | * The ksize() function is only guaranteed to work for pointers | |
5a1603be | 170 | * returned by kmalloc(). So handle arbitrary pointers here. |
6cfd53fc | 171 | */ |
5a1603be | 172 | return PAGE_SIZE << compound_order(page); |
1da177e4 LT |
173 | } |
174 | ||
b291f000 NP |
175 | int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, |
176 | unsigned long start, int len, int flags, | |
177 | struct page **pages, struct vm_area_struct **vmas) | |
1da177e4 | 178 | { |
910e46da | 179 | struct vm_area_struct *vma; |
7b4d5b8b DH |
180 | unsigned long vm_flags; |
181 | int i; | |
b291f000 NP |
182 | int write = !!(flags & GUP_FLAGS_WRITE); |
183 | int force = !!(flags & GUP_FLAGS_FORCE); | |
184 | int ignore = !!(flags & GUP_FLAGS_IGNORE_VMA_PERMISSIONS); | |
7b4d5b8b DH |
185 | |
186 | /* calculate required read or write permissions. | |
187 | * - if 'force' is set, we only require the "MAY" flags. | |
188 | */ | |
189 | vm_flags = write ? (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD); | |
190 | vm_flags &= force ? (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE); | |
1da177e4 LT |
191 | |
192 | for (i = 0; i < len; i++) { | |
910e46da | 193 | vma = find_vma(mm, start); |
7b4d5b8b DH |
194 | if (!vma) |
195 | goto finish_or_fault; | |
196 | ||
197 | /* protect what we can, including chardevs */ | |
198 | if (vma->vm_flags & (VM_IO | VM_PFNMAP) || | |
b291f000 | 199 | (!ignore && !(vm_flags & vma->vm_flags))) |
7b4d5b8b | 200 | goto finish_or_fault; |
910e46da | 201 | |
1da177e4 LT |
202 | if (pages) { |
203 | pages[i] = virt_to_page(start); | |
204 | if (pages[i]) | |
205 | page_cache_get(pages[i]); | |
206 | } | |
207 | if (vmas) | |
910e46da | 208 | vmas[i] = vma; |
1da177e4 LT |
209 | start += PAGE_SIZE; |
210 | } | |
7b4d5b8b DH |
211 | |
212 | return i; | |
213 | ||
214 | finish_or_fault: | |
215 | return i ? : -EFAULT; | |
1da177e4 | 216 | } |
b291f000 NP |
217 | |
218 | ||
219 | /* | |
220 | * get a list of pages in an address range belonging to the specified process | |
221 | * and indicate the VMA that covers each page | |
222 | * - this is potentially dodgy as we may end incrementing the page count of a | |
223 | * slab page or a secondary page from a compound page | |
224 | * - don't permit access to VMAs that don't support it, such as I/O mappings | |
225 | */ | |
226 | int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, | |
227 | unsigned long start, int len, int write, int force, | |
228 | struct page **pages, struct vm_area_struct **vmas) | |
229 | { | |
230 | int flags = 0; | |
231 | ||
232 | if (write) | |
233 | flags |= GUP_FLAGS_WRITE; | |
234 | if (force) | |
235 | flags |= GUP_FLAGS_FORCE; | |
236 | ||
237 | return __get_user_pages(tsk, mm, | |
238 | start, len, flags, | |
239 | pages, vmas); | |
240 | } | |
66aa2b4b GU |
241 | EXPORT_SYMBOL(get_user_pages); |
242 | ||
dfc2f91a PM |
243 | /** |
244 | * follow_pfn - look up PFN at a user virtual address | |
245 | * @vma: memory mapping | |
246 | * @address: user virtual address | |
247 | * @pfn: location to store found PFN | |
248 | * | |
249 | * Only IO mappings and raw PFN mappings are allowed. | |
250 | * | |
251 | * Returns zero and the pfn at @pfn on success, -ve otherwise. | |
252 | */ | |
253 | int follow_pfn(struct vm_area_struct *vma, unsigned long address, | |
254 | unsigned long *pfn) | |
255 | { | |
256 | if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) | |
257 | return -EINVAL; | |
258 | ||
259 | *pfn = address >> PAGE_SHIFT; | |
260 | return 0; | |
261 | } | |
262 | EXPORT_SYMBOL(follow_pfn); | |
263 | ||
1da177e4 LT |
264 | DEFINE_RWLOCK(vmlist_lock); |
265 | struct vm_struct *vmlist; | |
266 | ||
b3bdda02 | 267 | void vfree(const void *addr) |
1da177e4 LT |
268 | { |
269 | kfree(addr); | |
270 | } | |
b5073173 | 271 | EXPORT_SYMBOL(vfree); |
1da177e4 | 272 | |
dd0fc66f | 273 | void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot) |
1da177e4 LT |
274 | { |
275 | /* | |
8518609d RD |
276 | * You can't specify __GFP_HIGHMEM with kmalloc() since kmalloc() |
277 | * returns only a logical address. | |
1da177e4 | 278 | */ |
84097518 | 279 | return kmalloc(size, (gfp_mask | __GFP_COMP) & ~__GFP_HIGHMEM); |
1da177e4 | 280 | } |
b5073173 | 281 | EXPORT_SYMBOL(__vmalloc); |
1da177e4 | 282 | |
f905bc44 PM |
283 | void *vmalloc_user(unsigned long size) |
284 | { | |
285 | void *ret; | |
286 | ||
287 | ret = __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO, | |
288 | PAGE_KERNEL); | |
289 | if (ret) { | |
290 | struct vm_area_struct *vma; | |
291 | ||
292 | down_write(¤t->mm->mmap_sem); | |
293 | vma = find_vma(current->mm, (unsigned long)ret); | |
294 | if (vma) | |
295 | vma->vm_flags |= VM_USERMAP; | |
296 | up_write(¤t->mm->mmap_sem); | |
297 | } | |
298 | ||
299 | return ret; | |
300 | } | |
301 | EXPORT_SYMBOL(vmalloc_user); | |
302 | ||
b3bdda02 | 303 | struct page *vmalloc_to_page(const void *addr) |
1da177e4 LT |
304 | { |
305 | return virt_to_page(addr); | |
306 | } | |
b5073173 | 307 | EXPORT_SYMBOL(vmalloc_to_page); |
1da177e4 | 308 | |
b3bdda02 | 309 | unsigned long vmalloc_to_pfn(const void *addr) |
1da177e4 LT |
310 | { |
311 | return page_to_pfn(virt_to_page(addr)); | |
312 | } | |
b5073173 | 313 | EXPORT_SYMBOL(vmalloc_to_pfn); |
1da177e4 LT |
314 | |
315 | long vread(char *buf, char *addr, unsigned long count) | |
316 | { | |
317 | memcpy(buf, addr, count); | |
318 | return count; | |
319 | } | |
320 | ||
321 | long vwrite(char *buf, char *addr, unsigned long count) | |
322 | { | |
323 | /* Don't allow overflow */ | |
324 | if ((unsigned long) addr + count < count) | |
325 | count = -(unsigned long) addr; | |
326 | ||
327 | memcpy(addr, buf, count); | |
328 | return(count); | |
329 | } | |
330 | ||
331 | /* | |
332 | * vmalloc - allocate virtually continguos memory | |
333 | * | |
334 | * @size: allocation size | |
335 | * | |
336 | * Allocate enough pages to cover @size from the page level | |
337 | * allocator and map them into continguos kernel virtual space. | |
338 | * | |
c1c8897f | 339 | * For tight control over page level allocator and protection flags |
1da177e4 LT |
340 | * use __vmalloc() instead. |
341 | */ | |
342 | void *vmalloc(unsigned long size) | |
343 | { | |
344 | return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL); | |
345 | } | |
f6138882 AM |
346 | EXPORT_SYMBOL(vmalloc); |
347 | ||
348 | void *vmalloc_node(unsigned long size, int node) | |
349 | { | |
350 | return vmalloc(size); | |
351 | } | |
352 | EXPORT_SYMBOL(vmalloc_node); | |
1da177e4 | 353 | |
1af446ed PM |
354 | #ifndef PAGE_KERNEL_EXEC |
355 | # define PAGE_KERNEL_EXEC PAGE_KERNEL | |
356 | #endif | |
357 | ||
358 | /** | |
359 | * vmalloc_exec - allocate virtually contiguous, executable memory | |
360 | * @size: allocation size | |
361 | * | |
362 | * Kernel-internal function to allocate enough pages to cover @size | |
363 | * the page level allocator and map them into contiguous and | |
364 | * executable kernel virtual space. | |
365 | * | |
366 | * For tight control over page level allocator and protection flags | |
367 | * use __vmalloc() instead. | |
368 | */ | |
369 | ||
370 | void *vmalloc_exec(unsigned long size) | |
371 | { | |
372 | return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC); | |
373 | } | |
374 | ||
b5073173 PM |
375 | /** |
376 | * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) | |
1da177e4 LT |
377 | * @size: allocation size |
378 | * | |
379 | * Allocate enough 32bit PA addressable pages to cover @size from the | |
380 | * page level allocator and map them into continguos kernel virtual space. | |
381 | */ | |
382 | void *vmalloc_32(unsigned long size) | |
383 | { | |
384 | return __vmalloc(size, GFP_KERNEL, PAGE_KERNEL); | |
385 | } | |
b5073173 PM |
386 | EXPORT_SYMBOL(vmalloc_32); |
387 | ||
388 | /** | |
389 | * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory | |
390 | * @size: allocation size | |
391 | * | |
392 | * The resulting memory area is 32bit addressable and zeroed so it can be | |
393 | * mapped to userspace without leaking data. | |
f905bc44 PM |
394 | * |
395 | * VM_USERMAP is set on the corresponding VMA so that subsequent calls to | |
396 | * remap_vmalloc_range() are permissible. | |
b5073173 PM |
397 | */ |
398 | void *vmalloc_32_user(unsigned long size) | |
399 | { | |
f905bc44 PM |
400 | /* |
401 | * We'll have to sort out the ZONE_DMA bits for 64-bit, | |
402 | * but for now this can simply use vmalloc_user() directly. | |
403 | */ | |
404 | return vmalloc_user(size); | |
b5073173 PM |
405 | } |
406 | EXPORT_SYMBOL(vmalloc_32_user); | |
1da177e4 LT |
407 | |
408 | void *vmap(struct page **pages, unsigned int count, unsigned long flags, pgprot_t prot) | |
409 | { | |
410 | BUG(); | |
411 | return NULL; | |
412 | } | |
b5073173 | 413 | EXPORT_SYMBOL(vmap); |
1da177e4 | 414 | |
b3bdda02 | 415 | void vunmap(const void *addr) |
1da177e4 LT |
416 | { |
417 | BUG(); | |
418 | } | |
b5073173 | 419 | EXPORT_SYMBOL(vunmap); |
1da177e4 | 420 | |
eb6434d9 PM |
421 | void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot) |
422 | { | |
423 | BUG(); | |
424 | return NULL; | |
425 | } | |
426 | EXPORT_SYMBOL(vm_map_ram); | |
427 | ||
428 | void vm_unmap_ram(const void *mem, unsigned int count) | |
429 | { | |
430 | BUG(); | |
431 | } | |
432 | EXPORT_SYMBOL(vm_unmap_ram); | |
433 | ||
434 | void vm_unmap_aliases(void) | |
435 | { | |
436 | } | |
437 | EXPORT_SYMBOL_GPL(vm_unmap_aliases); | |
438 | ||
1eeb66a1 CH |
439 | /* |
440 | * Implement a stub for vmalloc_sync_all() if the architecture chose not to | |
441 | * have one. | |
442 | */ | |
443 | void __attribute__((weak)) vmalloc_sync_all(void) | |
444 | { | |
445 | } | |
446 | ||
b5073173 PM |
447 | int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, |
448 | struct page *page) | |
449 | { | |
450 | return -EINVAL; | |
451 | } | |
452 | EXPORT_SYMBOL(vm_insert_page); | |
453 | ||
1da177e4 LT |
454 | /* |
455 | * sys_brk() for the most part doesn't need the global kernel | |
456 | * lock, except when an application is doing something nasty | |
457 | * like trying to un-brk an area that has already been mapped | |
458 | * to a regular file. in this case, the unmapping will need | |
459 | * to invoke file system routines that need the global lock. | |
460 | */ | |
6a6160a7 | 461 | SYSCALL_DEFINE1(brk, unsigned long, brk) |
1da177e4 LT |
462 | { |
463 | struct mm_struct *mm = current->mm; | |
464 | ||
465 | if (brk < mm->start_brk || brk > mm->context.end_brk) | |
466 | return mm->brk; | |
467 | ||
468 | if (mm->brk == brk) | |
469 | return mm->brk; | |
470 | ||
471 | /* | |
472 | * Always allow shrinking brk | |
473 | */ | |
474 | if (brk <= mm->brk) { | |
475 | mm->brk = brk; | |
476 | return brk; | |
477 | } | |
478 | ||
479 | /* | |
480 | * Ok, looks good - let it rip. | |
481 | */ | |
482 | return mm->brk = brk; | |
483 | } | |
484 | ||
8feae131 DH |
485 | /* |
486 | * initialise the VMA and region record slabs | |
487 | */ | |
488 | void __init mmap_init(void) | |
1da177e4 | 489 | { |
00a62ce9 KM |
490 | int ret; |
491 | ||
492 | ret = percpu_counter_init(&vm_committed_as, 0); | |
493 | VM_BUG_ON(ret); | |
33e5d769 | 494 | vm_region_jar = KMEM_CACHE(vm_region, SLAB_PANIC); |
1da177e4 | 495 | } |
1da177e4 | 496 | |
3034097a | 497 | /* |
8feae131 DH |
498 | * validate the region tree |
499 | * - the caller must hold the region lock | |
3034097a | 500 | */ |
8feae131 DH |
501 | #ifdef CONFIG_DEBUG_NOMMU_REGIONS |
502 | static noinline void validate_nommu_regions(void) | |
3034097a | 503 | { |
8feae131 DH |
504 | struct vm_region *region, *last; |
505 | struct rb_node *p, *lastp; | |
3034097a | 506 | |
8feae131 DH |
507 | lastp = rb_first(&nommu_region_tree); |
508 | if (!lastp) | |
509 | return; | |
510 | ||
511 | last = rb_entry(lastp, struct vm_region, vm_rb); | |
33e5d769 DH |
512 | BUG_ON(unlikely(last->vm_end <= last->vm_start)); |
513 | BUG_ON(unlikely(last->vm_top < last->vm_end)); | |
8feae131 DH |
514 | |
515 | while ((p = rb_next(lastp))) { | |
516 | region = rb_entry(p, struct vm_region, vm_rb); | |
517 | last = rb_entry(lastp, struct vm_region, vm_rb); | |
518 | ||
33e5d769 DH |
519 | BUG_ON(unlikely(region->vm_end <= region->vm_start)); |
520 | BUG_ON(unlikely(region->vm_top < region->vm_end)); | |
521 | BUG_ON(unlikely(region->vm_start < last->vm_top)); | |
3034097a | 522 | |
8feae131 DH |
523 | lastp = p; |
524 | } | |
3034097a | 525 | } |
8feae131 | 526 | #else |
33e5d769 DH |
527 | static void validate_nommu_regions(void) |
528 | { | |
529 | } | |
8feae131 | 530 | #endif |
3034097a DH |
531 | |
532 | /* | |
8feae131 | 533 | * add a region into the global tree |
3034097a | 534 | */ |
8feae131 | 535 | static void add_nommu_region(struct vm_region *region) |
3034097a | 536 | { |
8feae131 DH |
537 | struct vm_region *pregion; |
538 | struct rb_node **p, *parent; | |
3034097a | 539 | |
8feae131 DH |
540 | validate_nommu_regions(); |
541 | ||
8feae131 DH |
542 | parent = NULL; |
543 | p = &nommu_region_tree.rb_node; | |
544 | while (*p) { | |
545 | parent = *p; | |
546 | pregion = rb_entry(parent, struct vm_region, vm_rb); | |
547 | if (region->vm_start < pregion->vm_start) | |
548 | p = &(*p)->rb_left; | |
549 | else if (region->vm_start > pregion->vm_start) | |
550 | p = &(*p)->rb_right; | |
551 | else if (pregion == region) | |
552 | return; | |
553 | else | |
554 | BUG(); | |
3034097a DH |
555 | } |
556 | ||
8feae131 DH |
557 | rb_link_node(®ion->vm_rb, parent, p); |
558 | rb_insert_color(®ion->vm_rb, &nommu_region_tree); | |
3034097a | 559 | |
8feae131 | 560 | validate_nommu_regions(); |
3034097a | 561 | } |
3034097a | 562 | |
930e652a | 563 | /* |
8feae131 | 564 | * delete a region from the global tree |
930e652a | 565 | */ |
8feae131 | 566 | static void delete_nommu_region(struct vm_region *region) |
930e652a | 567 | { |
8feae131 | 568 | BUG_ON(!nommu_region_tree.rb_node); |
930e652a | 569 | |
8feae131 DH |
570 | validate_nommu_regions(); |
571 | rb_erase(®ion->vm_rb, &nommu_region_tree); | |
572 | validate_nommu_regions(); | |
57c8f63e GU |
573 | } |
574 | ||
6fa5f80b | 575 | /* |
8feae131 | 576 | * free a contiguous series of pages |
6fa5f80b | 577 | */ |
8feae131 | 578 | static void free_page_series(unsigned long from, unsigned long to) |
6fa5f80b | 579 | { |
8feae131 DH |
580 | for (; from < to; from += PAGE_SIZE) { |
581 | struct page *page = virt_to_page(from); | |
582 | ||
583 | kdebug("- free %lx", from); | |
33e5d769 | 584 | atomic_long_dec(&mmap_pages_allocated); |
8feae131 | 585 | if (page_count(page) != 1) |
33e5d769 DH |
586 | kdebug("free page %p: refcount not one: %d", |
587 | page, page_count(page)); | |
8feae131 | 588 | put_page(page); |
6fa5f80b | 589 | } |
6fa5f80b DH |
590 | } |
591 | ||
3034097a | 592 | /* |
8feae131 | 593 | * release a reference to a region |
33e5d769 | 594 | * - the caller must hold the region semaphore for writing, which this releases |
dd8632a1 | 595 | * - the region may not have been added to the tree yet, in which case vm_top |
8feae131 | 596 | * will equal vm_start |
3034097a | 597 | */ |
8feae131 DH |
598 | static void __put_nommu_region(struct vm_region *region) |
599 | __releases(nommu_region_sem) | |
1da177e4 | 600 | { |
8feae131 | 601 | kenter("%p{%d}", region, atomic_read(®ion->vm_usage)); |
1da177e4 | 602 | |
8feae131 | 603 | BUG_ON(!nommu_region_tree.rb_node); |
1da177e4 | 604 | |
8feae131 | 605 | if (atomic_dec_and_test(®ion->vm_usage)) { |
dd8632a1 | 606 | if (region->vm_top > region->vm_start) |
8feae131 DH |
607 | delete_nommu_region(region); |
608 | up_write(&nommu_region_sem); | |
609 | ||
610 | if (region->vm_file) | |
611 | fput(region->vm_file); | |
612 | ||
613 | /* IO memory and memory shared directly out of the pagecache | |
614 | * from ramfs/tmpfs mustn't be released here */ | |
615 | if (region->vm_flags & VM_MAPPED_COPY) { | |
616 | kdebug("free series"); | |
dd8632a1 | 617 | free_page_series(region->vm_start, region->vm_top); |
8feae131 DH |
618 | } |
619 | kmem_cache_free(vm_region_jar, region); | |
620 | } else { | |
621 | up_write(&nommu_region_sem); | |
1da177e4 | 622 | } |
8feae131 | 623 | } |
1da177e4 | 624 | |
8feae131 DH |
625 | /* |
626 | * release a reference to a region | |
627 | */ | |
628 | static void put_nommu_region(struct vm_region *region) | |
629 | { | |
630 | down_write(&nommu_region_sem); | |
631 | __put_nommu_region(region); | |
1da177e4 LT |
632 | } |
633 | ||
3034097a | 634 | /* |
8feae131 DH |
635 | * add a VMA into a process's mm_struct in the appropriate place in the list |
636 | * and tree and add to the address space's page tree also if not an anonymous | |
637 | * page | |
638 | * - should be called with mm->mmap_sem held writelocked | |
3034097a | 639 | */ |
8feae131 | 640 | static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma) |
1da177e4 | 641 | { |
8feae131 | 642 | struct vm_area_struct *pvma, **pp; |
1da177e4 | 643 | struct address_space *mapping; |
8feae131 DH |
644 | struct rb_node **p, *parent; |
645 | ||
646 | kenter(",%p", vma); | |
647 | ||
648 | BUG_ON(!vma->vm_region); | |
649 | ||
650 | mm->map_count++; | |
651 | vma->vm_mm = mm; | |
1da177e4 LT |
652 | |
653 | /* add the VMA to the mapping */ | |
654 | if (vma->vm_file) { | |
655 | mapping = vma->vm_file->f_mapping; | |
656 | ||
657 | flush_dcache_mmap_lock(mapping); | |
658 | vma_prio_tree_insert(vma, &mapping->i_mmap); | |
659 | flush_dcache_mmap_unlock(mapping); | |
660 | } | |
661 | ||
8feae131 DH |
662 | /* add the VMA to the tree */ |
663 | parent = NULL; | |
664 | p = &mm->mm_rb.rb_node; | |
1da177e4 LT |
665 | while (*p) { |
666 | parent = *p; | |
667 | pvma = rb_entry(parent, struct vm_area_struct, vm_rb); | |
668 | ||
8feae131 DH |
669 | /* sort by: start addr, end addr, VMA struct addr in that order |
670 | * (the latter is necessary as we may get identical VMAs) */ | |
671 | if (vma->vm_start < pvma->vm_start) | |
1da177e4 | 672 | p = &(*p)->rb_left; |
8feae131 | 673 | else if (vma->vm_start > pvma->vm_start) |
1da177e4 | 674 | p = &(*p)->rb_right; |
8feae131 DH |
675 | else if (vma->vm_end < pvma->vm_end) |
676 | p = &(*p)->rb_left; | |
677 | else if (vma->vm_end > pvma->vm_end) | |
678 | p = &(*p)->rb_right; | |
679 | else if (vma < pvma) | |
680 | p = &(*p)->rb_left; | |
681 | else if (vma > pvma) | |
682 | p = &(*p)->rb_right; | |
683 | else | |
684 | BUG(); | |
1da177e4 LT |
685 | } |
686 | ||
687 | rb_link_node(&vma->vm_rb, parent, p); | |
8feae131 DH |
688 | rb_insert_color(&vma->vm_rb, &mm->mm_rb); |
689 | ||
690 | /* add VMA to the VMA list also */ | |
691 | for (pp = &mm->mmap; (pvma = *pp); pp = &(*pp)->vm_next) { | |
692 | if (pvma->vm_start > vma->vm_start) | |
693 | break; | |
694 | if (pvma->vm_start < vma->vm_start) | |
695 | continue; | |
696 | if (pvma->vm_end < vma->vm_end) | |
697 | break; | |
698 | } | |
699 | ||
700 | vma->vm_next = *pp; | |
701 | *pp = vma; | |
1da177e4 LT |
702 | } |
703 | ||
3034097a | 704 | /* |
8feae131 | 705 | * delete a VMA from its owning mm_struct and address space |
3034097a | 706 | */ |
8feae131 | 707 | static void delete_vma_from_mm(struct vm_area_struct *vma) |
1da177e4 | 708 | { |
8feae131 | 709 | struct vm_area_struct **pp; |
1da177e4 | 710 | struct address_space *mapping; |
8feae131 DH |
711 | struct mm_struct *mm = vma->vm_mm; |
712 | ||
713 | kenter("%p", vma); | |
714 | ||
715 | mm->map_count--; | |
716 | if (mm->mmap_cache == vma) | |
717 | mm->mmap_cache = NULL; | |
1da177e4 LT |
718 | |
719 | /* remove the VMA from the mapping */ | |
720 | if (vma->vm_file) { | |
721 | mapping = vma->vm_file->f_mapping; | |
722 | ||
723 | flush_dcache_mmap_lock(mapping); | |
724 | vma_prio_tree_remove(vma, &mapping->i_mmap); | |
725 | flush_dcache_mmap_unlock(mapping); | |
726 | } | |
727 | ||
8feae131 DH |
728 | /* remove from the MM's tree and list */ |
729 | rb_erase(&vma->vm_rb, &mm->mm_rb); | |
730 | for (pp = &mm->mmap; *pp; pp = &(*pp)->vm_next) { | |
731 | if (*pp == vma) { | |
732 | *pp = vma->vm_next; | |
733 | break; | |
734 | } | |
735 | } | |
736 | ||
737 | vma->vm_mm = NULL; | |
738 | } | |
739 | ||
740 | /* | |
741 | * destroy a VMA record | |
742 | */ | |
743 | static void delete_vma(struct mm_struct *mm, struct vm_area_struct *vma) | |
744 | { | |
745 | kenter("%p", vma); | |
746 | if (vma->vm_ops && vma->vm_ops->close) | |
747 | vma->vm_ops->close(vma); | |
748 | if (vma->vm_file) { | |
749 | fput(vma->vm_file); | |
750 | if (vma->vm_flags & VM_EXECUTABLE) | |
751 | removed_exe_file_vma(mm); | |
752 | } | |
753 | put_nommu_region(vma->vm_region); | |
754 | kmem_cache_free(vm_area_cachep, vma); | |
755 | } | |
756 | ||
757 | /* | |
758 | * look up the first VMA in which addr resides, NULL if none | |
759 | * - should be called with mm->mmap_sem at least held readlocked | |
760 | */ | |
761 | struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) | |
762 | { | |
763 | struct vm_area_struct *vma; | |
764 | struct rb_node *n = mm->mm_rb.rb_node; | |
765 | ||
766 | /* check the cache first */ | |
767 | vma = mm->mmap_cache; | |
768 | if (vma && vma->vm_start <= addr && vma->vm_end > addr) | |
769 | return vma; | |
770 | ||
771 | /* trawl the tree (there may be multiple mappings in which addr | |
772 | * resides) */ | |
773 | for (n = rb_first(&mm->mm_rb); n; n = rb_next(n)) { | |
774 | vma = rb_entry(n, struct vm_area_struct, vm_rb); | |
775 | if (vma->vm_start > addr) | |
776 | return NULL; | |
777 | if (vma->vm_end > addr) { | |
778 | mm->mmap_cache = vma; | |
779 | return vma; | |
780 | } | |
781 | } | |
782 | ||
783 | return NULL; | |
784 | } | |
785 | EXPORT_SYMBOL(find_vma); | |
786 | ||
787 | /* | |
788 | * find a VMA | |
789 | * - we don't extend stack VMAs under NOMMU conditions | |
790 | */ | |
791 | struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr) | |
792 | { | |
793 | return find_vma(mm, addr); | |
794 | } | |
795 | ||
796 | /* | |
797 | * expand a stack to a given address | |
798 | * - not supported under NOMMU conditions | |
799 | */ | |
800 | int expand_stack(struct vm_area_struct *vma, unsigned long address) | |
801 | { | |
802 | return -ENOMEM; | |
803 | } | |
804 | ||
805 | /* | |
806 | * look up the first VMA exactly that exactly matches addr | |
807 | * - should be called with mm->mmap_sem at least held readlocked | |
808 | */ | |
809 | static struct vm_area_struct *find_vma_exact(struct mm_struct *mm, | |
810 | unsigned long addr, | |
811 | unsigned long len) | |
812 | { | |
813 | struct vm_area_struct *vma; | |
814 | struct rb_node *n = mm->mm_rb.rb_node; | |
815 | unsigned long end = addr + len; | |
816 | ||
817 | /* check the cache first */ | |
818 | vma = mm->mmap_cache; | |
819 | if (vma && vma->vm_start == addr && vma->vm_end == end) | |
820 | return vma; | |
821 | ||
822 | /* trawl the tree (there may be multiple mappings in which addr | |
823 | * resides) */ | |
824 | for (n = rb_first(&mm->mm_rb); n; n = rb_next(n)) { | |
825 | vma = rb_entry(n, struct vm_area_struct, vm_rb); | |
826 | if (vma->vm_start < addr) | |
827 | continue; | |
828 | if (vma->vm_start > addr) | |
829 | return NULL; | |
830 | if (vma->vm_end == end) { | |
831 | mm->mmap_cache = vma; | |
832 | return vma; | |
833 | } | |
834 | } | |
835 | ||
836 | return NULL; | |
1da177e4 LT |
837 | } |
838 | ||
839 | /* | |
840 | * determine whether a mapping should be permitted and, if so, what sort of | |
841 | * mapping we're capable of supporting | |
842 | */ | |
843 | static int validate_mmap_request(struct file *file, | |
844 | unsigned long addr, | |
845 | unsigned long len, | |
846 | unsigned long prot, | |
847 | unsigned long flags, | |
848 | unsigned long pgoff, | |
849 | unsigned long *_capabilities) | |
850 | { | |
8feae131 | 851 | unsigned long capabilities, rlen; |
1da177e4 LT |
852 | unsigned long reqprot = prot; |
853 | int ret; | |
854 | ||
855 | /* do the simple checks first */ | |
856 | if (flags & MAP_FIXED || addr) { | |
857 | printk(KERN_DEBUG | |
858 | "%d: Can't do fixed-address/overlay mmap of RAM\n", | |
859 | current->pid); | |
860 | return -EINVAL; | |
861 | } | |
862 | ||
863 | if ((flags & MAP_TYPE) != MAP_PRIVATE && | |
864 | (flags & MAP_TYPE) != MAP_SHARED) | |
865 | return -EINVAL; | |
866 | ||
f81cff0d | 867 | if (!len) |
1da177e4 LT |
868 | return -EINVAL; |
869 | ||
f81cff0d | 870 | /* Careful about overflows.. */ |
8feae131 DH |
871 | rlen = PAGE_ALIGN(len); |
872 | if (!rlen || rlen > TASK_SIZE) | |
f81cff0d MF |
873 | return -ENOMEM; |
874 | ||
1da177e4 | 875 | /* offset overflow? */ |
8feae131 | 876 | if ((pgoff + (rlen >> PAGE_SHIFT)) < pgoff) |
f81cff0d | 877 | return -EOVERFLOW; |
1da177e4 LT |
878 | |
879 | if (file) { | |
880 | /* validate file mapping requests */ | |
881 | struct address_space *mapping; | |
882 | ||
883 | /* files must support mmap */ | |
884 | if (!file->f_op || !file->f_op->mmap) | |
885 | return -ENODEV; | |
886 | ||
887 | /* work out if what we've got could possibly be shared | |
888 | * - we support chardevs that provide their own "memory" | |
889 | * - we support files/blockdevs that are memory backed | |
890 | */ | |
891 | mapping = file->f_mapping; | |
892 | if (!mapping) | |
e9536ae7 | 893 | mapping = file->f_path.dentry->d_inode->i_mapping; |
1da177e4 LT |
894 | |
895 | capabilities = 0; | |
896 | if (mapping && mapping->backing_dev_info) | |
897 | capabilities = mapping->backing_dev_info->capabilities; | |
898 | ||
899 | if (!capabilities) { | |
900 | /* no explicit capabilities set, so assume some | |
901 | * defaults */ | |
e9536ae7 | 902 | switch (file->f_path.dentry->d_inode->i_mode & S_IFMT) { |
1da177e4 LT |
903 | case S_IFREG: |
904 | case S_IFBLK: | |
905 | capabilities = BDI_CAP_MAP_COPY; | |
906 | break; | |
907 | ||
908 | case S_IFCHR: | |
909 | capabilities = | |
910 | BDI_CAP_MAP_DIRECT | | |
911 | BDI_CAP_READ_MAP | | |
912 | BDI_CAP_WRITE_MAP; | |
913 | break; | |
914 | ||
915 | default: | |
916 | return -EINVAL; | |
917 | } | |
918 | } | |
919 | ||
920 | /* eliminate any capabilities that we can't support on this | |
921 | * device */ | |
922 | if (!file->f_op->get_unmapped_area) | |
923 | capabilities &= ~BDI_CAP_MAP_DIRECT; | |
924 | if (!file->f_op->read) | |
925 | capabilities &= ~BDI_CAP_MAP_COPY; | |
926 | ||
927 | if (flags & MAP_SHARED) { | |
928 | /* do checks for writing, appending and locking */ | |
929 | if ((prot & PROT_WRITE) && | |
930 | !(file->f_mode & FMODE_WRITE)) | |
931 | return -EACCES; | |
932 | ||
e9536ae7 | 933 | if (IS_APPEND(file->f_path.dentry->d_inode) && |
1da177e4 LT |
934 | (file->f_mode & FMODE_WRITE)) |
935 | return -EACCES; | |
936 | ||
e9536ae7 | 937 | if (locks_verify_locked(file->f_path.dentry->d_inode)) |
1da177e4 LT |
938 | return -EAGAIN; |
939 | ||
940 | if (!(capabilities & BDI_CAP_MAP_DIRECT)) | |
941 | return -ENODEV; | |
942 | ||
943 | if (((prot & PROT_READ) && !(capabilities & BDI_CAP_READ_MAP)) || | |
944 | ((prot & PROT_WRITE) && !(capabilities & BDI_CAP_WRITE_MAP)) || | |
945 | ((prot & PROT_EXEC) && !(capabilities & BDI_CAP_EXEC_MAP)) | |
946 | ) { | |
947 | printk("MAP_SHARED not completely supported on !MMU\n"); | |
948 | return -EINVAL; | |
949 | } | |
950 | ||
951 | /* we mustn't privatise shared mappings */ | |
952 | capabilities &= ~BDI_CAP_MAP_COPY; | |
953 | } | |
954 | else { | |
955 | /* we're going to read the file into private memory we | |
956 | * allocate */ | |
957 | if (!(capabilities & BDI_CAP_MAP_COPY)) | |
958 | return -ENODEV; | |
959 | ||
960 | /* we don't permit a private writable mapping to be | |
961 | * shared with the backing device */ | |
962 | if (prot & PROT_WRITE) | |
963 | capabilities &= ~BDI_CAP_MAP_DIRECT; | |
964 | } | |
965 | ||
966 | /* handle executable mappings and implied executable | |
967 | * mappings */ | |
e9536ae7 | 968 | if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) { |
1da177e4 LT |
969 | if (prot & PROT_EXEC) |
970 | return -EPERM; | |
971 | } | |
972 | else if ((prot & PROT_READ) && !(prot & PROT_EXEC)) { | |
973 | /* handle implication of PROT_EXEC by PROT_READ */ | |
974 | if (current->personality & READ_IMPLIES_EXEC) { | |
975 | if (capabilities & BDI_CAP_EXEC_MAP) | |
976 | prot |= PROT_EXEC; | |
977 | } | |
978 | } | |
979 | else if ((prot & PROT_READ) && | |
980 | (prot & PROT_EXEC) && | |
981 | !(capabilities & BDI_CAP_EXEC_MAP) | |
982 | ) { | |
983 | /* backing file is not executable, try to copy */ | |
984 | capabilities &= ~BDI_CAP_MAP_DIRECT; | |
985 | } | |
986 | } | |
987 | else { | |
988 | /* anonymous mappings are always memory backed and can be | |
989 | * privately mapped | |
990 | */ | |
991 | capabilities = BDI_CAP_MAP_COPY; | |
992 | ||
993 | /* handle PROT_EXEC implication by PROT_READ */ | |
994 | if ((prot & PROT_READ) && | |
995 | (current->personality & READ_IMPLIES_EXEC)) | |
996 | prot |= PROT_EXEC; | |
997 | } | |
998 | ||
999 | /* allow the security API to have its say */ | |
ed032189 | 1000 | ret = security_file_mmap(file, reqprot, prot, flags, addr, 0); |
1da177e4 LT |
1001 | if (ret < 0) |
1002 | return ret; | |
1003 | ||
1004 | /* looks okay */ | |
1005 | *_capabilities = capabilities; | |
1006 | return 0; | |
1007 | } | |
1008 | ||
1009 | /* | |
1010 | * we've determined that we can make the mapping, now translate what we | |
1011 | * now know into VMA flags | |
1012 | */ | |
1013 | static unsigned long determine_vm_flags(struct file *file, | |
1014 | unsigned long prot, | |
1015 | unsigned long flags, | |
1016 | unsigned long capabilities) | |
1017 | { | |
1018 | unsigned long vm_flags; | |
1019 | ||
1020 | vm_flags = calc_vm_prot_bits(prot) | calc_vm_flag_bits(flags); | |
1021 | vm_flags |= VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC; | |
1022 | /* vm_flags |= mm->def_flags; */ | |
1023 | ||
1024 | if (!(capabilities & BDI_CAP_MAP_DIRECT)) { | |
1025 | /* attempt to share read-only copies of mapped file chunks */ | |
1026 | if (file && !(prot & PROT_WRITE)) | |
1027 | vm_flags |= VM_MAYSHARE; | |
1028 | } | |
1029 | else { | |
1030 | /* overlay a shareable mapping on the backing device or inode | |
1031 | * if possible - used for chardevs, ramfs/tmpfs/shmfs and | |
1032 | * romfs/cramfs */ | |
1033 | if (flags & MAP_SHARED) | |
1034 | vm_flags |= VM_MAYSHARE | VM_SHARED; | |
1035 | else if ((((vm_flags & capabilities) ^ vm_flags) & BDI_CAP_VMFLAGS) == 0) | |
1036 | vm_flags |= VM_MAYSHARE; | |
1037 | } | |
1038 | ||
1039 | /* refuse to let anyone share private mappings with this process if | |
1040 | * it's being traced - otherwise breakpoints set in it may interfere | |
1041 | * with another untraced process | |
1042 | */ | |
fa8e26cc | 1043 | if ((flags & MAP_PRIVATE) && tracehook_expect_breakpoints(current)) |
1da177e4 LT |
1044 | vm_flags &= ~VM_MAYSHARE; |
1045 | ||
1046 | return vm_flags; | |
1047 | } | |
1048 | ||
1049 | /* | |
8feae131 DH |
1050 | * set up a shared mapping on a file (the driver or filesystem provides and |
1051 | * pins the storage) | |
1da177e4 | 1052 | */ |
8feae131 | 1053 | static int do_mmap_shared_file(struct vm_area_struct *vma) |
1da177e4 LT |
1054 | { |
1055 | int ret; | |
1056 | ||
1057 | ret = vma->vm_file->f_op->mmap(vma->vm_file, vma); | |
dd8632a1 PM |
1058 | if (ret == 0) { |
1059 | vma->vm_region->vm_top = vma->vm_region->vm_end; | |
1060 | return ret; | |
1061 | } | |
1da177e4 LT |
1062 | if (ret != -ENOSYS) |
1063 | return ret; | |
1064 | ||
1065 | /* getting an ENOSYS error indicates that direct mmap isn't | |
1066 | * possible (as opposed to tried but failed) so we'll fall | |
1067 | * through to making a private copy of the data and mapping | |
1068 | * that if we can */ | |
1069 | return -ENODEV; | |
1070 | } | |
1071 | ||
1072 | /* | |
1073 | * set up a private mapping or an anonymous shared mapping | |
1074 | */ | |
8feae131 DH |
1075 | static int do_mmap_private(struct vm_area_struct *vma, |
1076 | struct vm_region *region, | |
1077 | unsigned long len) | |
1da177e4 | 1078 | { |
8feae131 DH |
1079 | struct page *pages; |
1080 | unsigned long total, point, n, rlen; | |
1da177e4 | 1081 | void *base; |
8feae131 | 1082 | int ret, order; |
1da177e4 LT |
1083 | |
1084 | /* invoke the file's mapping function so that it can keep track of | |
1085 | * shared mappings on devices or memory | |
1086 | * - VM_MAYSHARE will be set if it may attempt to share | |
1087 | */ | |
1088 | if (vma->vm_file) { | |
1089 | ret = vma->vm_file->f_op->mmap(vma->vm_file, vma); | |
dd8632a1 | 1090 | if (ret == 0) { |
1da177e4 | 1091 | /* shouldn't return success if we're not sharing */ |
dd8632a1 PM |
1092 | BUG_ON(!(vma->vm_flags & VM_MAYSHARE)); |
1093 | vma->vm_region->vm_top = vma->vm_region->vm_end; | |
1094 | return ret; | |
1da177e4 | 1095 | } |
dd8632a1 PM |
1096 | if (ret != -ENOSYS) |
1097 | return ret; | |
1da177e4 LT |
1098 | |
1099 | /* getting an ENOSYS error indicates that direct mmap isn't | |
1100 | * possible (as opposed to tried but failed) so we'll try to | |
1101 | * make a private copy of the data and map that instead */ | |
1102 | } | |
1103 | ||
8feae131 DH |
1104 | rlen = PAGE_ALIGN(len); |
1105 | ||
1da177e4 LT |
1106 | /* allocate some memory to hold the mapping |
1107 | * - note that this may not return a page-aligned address if the object | |
1108 | * we're allocating is smaller than a page | |
1109 | */ | |
8feae131 DH |
1110 | order = get_order(rlen); |
1111 | kdebug("alloc order %d for %lx", order, len); | |
1112 | ||
1113 | pages = alloc_pages(GFP_KERNEL, order); | |
1114 | if (!pages) | |
1da177e4 LT |
1115 | goto enomem; |
1116 | ||
8feae131 | 1117 | total = 1 << order; |
33e5d769 | 1118 | atomic_long_add(total, &mmap_pages_allocated); |
8feae131 DH |
1119 | |
1120 | point = rlen >> PAGE_SHIFT; | |
dd8632a1 PM |
1121 | |
1122 | /* we allocated a power-of-2 sized page set, so we may want to trim off | |
1123 | * the excess */ | |
1124 | if (sysctl_nr_trim_pages && total - point >= sysctl_nr_trim_pages) { | |
1125 | while (total > point) { | |
1126 | order = ilog2(total - point); | |
1127 | n = 1 << order; | |
1128 | kdebug("shave %lu/%lu @%lu", n, total - point, total); | |
33e5d769 | 1129 | atomic_long_sub(n, &mmap_pages_allocated); |
dd8632a1 PM |
1130 | total -= n; |
1131 | set_page_refcounted(pages + total); | |
1132 | __free_pages(pages + total, order); | |
1133 | } | |
8feae131 DH |
1134 | } |
1135 | ||
8feae131 DH |
1136 | for (point = 1; point < total; point++) |
1137 | set_page_refcounted(&pages[point]); | |
1da177e4 | 1138 | |
8feae131 DH |
1139 | base = page_address(pages); |
1140 | region->vm_flags = vma->vm_flags |= VM_MAPPED_COPY; | |
1141 | region->vm_start = (unsigned long) base; | |
1142 | region->vm_end = region->vm_start + rlen; | |
dd8632a1 | 1143 | region->vm_top = region->vm_start + (total << PAGE_SHIFT); |
8feae131 DH |
1144 | |
1145 | vma->vm_start = region->vm_start; | |
1146 | vma->vm_end = region->vm_start + len; | |
1da177e4 LT |
1147 | |
1148 | if (vma->vm_file) { | |
1149 | /* read the contents of a file into the copy */ | |
1150 | mm_segment_t old_fs; | |
1151 | loff_t fpos; | |
1152 | ||
1153 | fpos = vma->vm_pgoff; | |
1154 | fpos <<= PAGE_SHIFT; | |
1155 | ||
1156 | old_fs = get_fs(); | |
1157 | set_fs(KERNEL_DS); | |
8feae131 | 1158 | ret = vma->vm_file->f_op->read(vma->vm_file, base, rlen, &fpos); |
1da177e4 LT |
1159 | set_fs(old_fs); |
1160 | ||
1161 | if (ret < 0) | |
1162 | goto error_free; | |
1163 | ||
1164 | /* clear the last little bit */ | |
8feae131 DH |
1165 | if (ret < rlen) |
1166 | memset(base + ret, 0, rlen - ret); | |
1da177e4 LT |
1167 | |
1168 | } else { | |
1169 | /* if it's an anonymous mapping, then just clear it */ | |
8feae131 | 1170 | memset(base, 0, rlen); |
1da177e4 LT |
1171 | } |
1172 | ||
1173 | return 0; | |
1174 | ||
1175 | error_free: | |
8feae131 DH |
1176 | free_page_series(region->vm_start, region->vm_end); |
1177 | region->vm_start = vma->vm_start = 0; | |
1178 | region->vm_end = vma->vm_end = 0; | |
dd8632a1 | 1179 | region->vm_top = 0; |
1da177e4 LT |
1180 | return ret; |
1181 | ||
1182 | enomem: | |
05ae6fa3 GU |
1183 | printk("Allocation of length %lu from process %d (%s) failed\n", |
1184 | len, current->pid, current->comm); | |
1da177e4 LT |
1185 | show_free_areas(); |
1186 | return -ENOMEM; | |
1187 | } | |
1188 | ||
1189 | /* | |
1190 | * handle mapping creation for uClinux | |
1191 | */ | |
1192 | unsigned long do_mmap_pgoff(struct file *file, | |
1193 | unsigned long addr, | |
1194 | unsigned long len, | |
1195 | unsigned long prot, | |
1196 | unsigned long flags, | |
1197 | unsigned long pgoff) | |
1198 | { | |
8feae131 DH |
1199 | struct vm_area_struct *vma; |
1200 | struct vm_region *region; | |
1da177e4 | 1201 | struct rb_node *rb; |
8feae131 | 1202 | unsigned long capabilities, vm_flags, result; |
1da177e4 LT |
1203 | int ret; |
1204 | ||
8feae131 DH |
1205 | kenter(",%lx,%lx,%lx,%lx,%lx", addr, len, prot, flags, pgoff); |
1206 | ||
7cd94146 EP |
1207 | if (!(flags & MAP_FIXED)) |
1208 | addr = round_hint_to_min(addr); | |
1209 | ||
1da177e4 LT |
1210 | /* decide whether we should attempt the mapping, and if so what sort of |
1211 | * mapping */ | |
1212 | ret = validate_mmap_request(file, addr, len, prot, flags, pgoff, | |
1213 | &capabilities); | |
8feae131 DH |
1214 | if (ret < 0) { |
1215 | kleave(" = %d [val]", ret); | |
1da177e4 | 1216 | return ret; |
8feae131 | 1217 | } |
1da177e4 LT |
1218 | |
1219 | /* we've determined that we can make the mapping, now translate what we | |
1220 | * now know into VMA flags */ | |
1221 | vm_flags = determine_vm_flags(file, prot, flags, capabilities); | |
1222 | ||
8feae131 DH |
1223 | /* we're going to need to record the mapping */ |
1224 | region = kmem_cache_zalloc(vm_region_jar, GFP_KERNEL); | |
1225 | if (!region) | |
1226 | goto error_getting_region; | |
1227 | ||
1228 | vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL); | |
1229 | if (!vma) | |
1230 | goto error_getting_vma; | |
1da177e4 | 1231 | |
8feae131 DH |
1232 | atomic_set(®ion->vm_usage, 1); |
1233 | region->vm_flags = vm_flags; | |
1234 | region->vm_pgoff = pgoff; | |
1235 | ||
1236 | INIT_LIST_HEAD(&vma->anon_vma_node); | |
1237 | vma->vm_flags = vm_flags; | |
1238 | vma->vm_pgoff = pgoff; | |
1da177e4 | 1239 | |
8feae131 DH |
1240 | if (file) { |
1241 | region->vm_file = file; | |
1242 | get_file(file); | |
1243 | vma->vm_file = file; | |
1244 | get_file(file); | |
1245 | if (vm_flags & VM_EXECUTABLE) { | |
1246 | added_exe_file_vma(current->mm); | |
1247 | vma->vm_mm = current->mm; | |
1248 | } | |
1249 | } | |
1250 | ||
1251 | down_write(&nommu_region_sem); | |
1252 | ||
1253 | /* if we want to share, we need to check for regions created by other | |
1da177e4 | 1254 | * mmap() calls that overlap with our proposed mapping |
8feae131 | 1255 | * - we can only share with a superset match on most regular files |
1da177e4 LT |
1256 | * - shared mappings on character devices and memory backed files are |
1257 | * permitted to overlap inexactly as far as we are concerned for in | |
1258 | * these cases, sharing is handled in the driver or filesystem rather | |
1259 | * than here | |
1260 | */ | |
1261 | if (vm_flags & VM_MAYSHARE) { | |
8feae131 DH |
1262 | struct vm_region *pregion; |
1263 | unsigned long pglen, rpglen, pgend, rpgend, start; | |
1da177e4 | 1264 | |
8feae131 DH |
1265 | pglen = (len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
1266 | pgend = pgoff + pglen; | |
165b2392 | 1267 | |
8feae131 DH |
1268 | for (rb = rb_first(&nommu_region_tree); rb; rb = rb_next(rb)) { |
1269 | pregion = rb_entry(rb, struct vm_region, vm_rb); | |
1da177e4 | 1270 | |
8feae131 | 1271 | if (!(pregion->vm_flags & VM_MAYSHARE)) |
1da177e4 LT |
1272 | continue; |
1273 | ||
1274 | /* search for overlapping mappings on the same file */ | |
8feae131 DH |
1275 | if (pregion->vm_file->f_path.dentry->d_inode != |
1276 | file->f_path.dentry->d_inode) | |
1da177e4 LT |
1277 | continue; |
1278 | ||
8feae131 | 1279 | if (pregion->vm_pgoff >= pgend) |
1da177e4 LT |
1280 | continue; |
1281 | ||
8feae131 DH |
1282 | rpglen = pregion->vm_end - pregion->vm_start; |
1283 | rpglen = (rpglen + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
1284 | rpgend = pregion->vm_pgoff + rpglen; | |
1285 | if (pgoff >= rpgend) | |
1da177e4 LT |
1286 | continue; |
1287 | ||
8feae131 DH |
1288 | /* handle inexactly overlapping matches between |
1289 | * mappings */ | |
1290 | if ((pregion->vm_pgoff != pgoff || rpglen != pglen) && | |
1291 | !(pgoff >= pregion->vm_pgoff && pgend <= rpgend)) { | |
1292 | /* new mapping is not a subset of the region */ | |
1da177e4 LT |
1293 | if (!(capabilities & BDI_CAP_MAP_DIRECT)) |
1294 | goto sharing_violation; | |
1295 | continue; | |
1296 | } | |
1297 | ||
8feae131 DH |
1298 | /* we've found a region we can share */ |
1299 | atomic_inc(&pregion->vm_usage); | |
1300 | vma->vm_region = pregion; | |
1301 | start = pregion->vm_start; | |
1302 | start += (pgoff - pregion->vm_pgoff) << PAGE_SHIFT; | |
1303 | vma->vm_start = start; | |
1304 | vma->vm_end = start + len; | |
1305 | ||
1306 | if (pregion->vm_flags & VM_MAPPED_COPY) { | |
1307 | kdebug("share copy"); | |
1308 | vma->vm_flags |= VM_MAPPED_COPY; | |
1309 | } else { | |
1310 | kdebug("share mmap"); | |
1311 | ret = do_mmap_shared_file(vma); | |
1312 | if (ret < 0) { | |
1313 | vma->vm_region = NULL; | |
1314 | vma->vm_start = 0; | |
1315 | vma->vm_end = 0; | |
1316 | atomic_dec(&pregion->vm_usage); | |
1317 | pregion = NULL; | |
1318 | goto error_just_free; | |
1319 | } | |
1320 | } | |
1321 | fput(region->vm_file); | |
1322 | kmem_cache_free(vm_region_jar, region); | |
1323 | region = pregion; | |
1324 | result = start; | |
1325 | goto share; | |
1da177e4 LT |
1326 | } |
1327 | ||
1da177e4 LT |
1328 | /* obtain the address at which to make a shared mapping |
1329 | * - this is the hook for quasi-memory character devices to | |
1330 | * tell us the location of a shared mapping | |
1331 | */ | |
1332 | if (file && file->f_op->get_unmapped_area) { | |
1333 | addr = file->f_op->get_unmapped_area(file, addr, len, | |
1334 | pgoff, flags); | |
1335 | if (IS_ERR((void *) addr)) { | |
1336 | ret = addr; | |
1337 | if (ret != (unsigned long) -ENOSYS) | |
8feae131 | 1338 | goto error_just_free; |
1da177e4 LT |
1339 | |
1340 | /* the driver refused to tell us where to site | |
1341 | * the mapping so we'll have to attempt to copy | |
1342 | * it */ | |
1343 | ret = (unsigned long) -ENODEV; | |
1344 | if (!(capabilities & BDI_CAP_MAP_COPY)) | |
8feae131 | 1345 | goto error_just_free; |
1da177e4 LT |
1346 | |
1347 | capabilities &= ~BDI_CAP_MAP_DIRECT; | |
8feae131 DH |
1348 | } else { |
1349 | vma->vm_start = region->vm_start = addr; | |
1350 | vma->vm_end = region->vm_end = addr + len; | |
1da177e4 LT |
1351 | } |
1352 | } | |
1353 | } | |
1354 | ||
8feae131 | 1355 | vma->vm_region = region; |
1da177e4 LT |
1356 | |
1357 | /* set up the mapping */ | |
1358 | if (file && vma->vm_flags & VM_SHARED) | |
8feae131 | 1359 | ret = do_mmap_shared_file(vma); |
1da177e4 | 1360 | else |
8feae131 | 1361 | ret = do_mmap_private(vma, region, len); |
1da177e4 | 1362 | if (ret < 0) |
8feae131 DH |
1363 | goto error_put_region; |
1364 | ||
1365 | add_nommu_region(region); | |
1da177e4 LT |
1366 | |
1367 | /* okay... we have a mapping; now we have to register it */ | |
8feae131 | 1368 | result = vma->vm_start; |
1da177e4 | 1369 | |
1da177e4 LT |
1370 | current->mm->total_vm += len >> PAGE_SHIFT; |
1371 | ||
8feae131 DH |
1372 | share: |
1373 | add_vma_to_mm(current->mm, vma); | |
1da177e4 | 1374 | |
8feae131 | 1375 | up_write(&nommu_region_sem); |
1da177e4 LT |
1376 | |
1377 | if (prot & PROT_EXEC) | |
8feae131 | 1378 | flush_icache_range(result, result + len); |
1da177e4 | 1379 | |
8feae131 DH |
1380 | kleave(" = %lx", result); |
1381 | return result; | |
1da177e4 | 1382 | |
8feae131 DH |
1383 | error_put_region: |
1384 | __put_nommu_region(region); | |
1da177e4 | 1385 | if (vma) { |
925d1c40 | 1386 | if (vma->vm_file) { |
3fcd03e0 | 1387 | fput(vma->vm_file); |
925d1c40 MH |
1388 | if (vma->vm_flags & VM_EXECUTABLE) |
1389 | removed_exe_file_vma(vma->vm_mm); | |
1390 | } | |
8feae131 | 1391 | kmem_cache_free(vm_area_cachep, vma); |
1da177e4 | 1392 | } |
8feae131 | 1393 | kleave(" = %d [pr]", ret); |
1da177e4 LT |
1394 | return ret; |
1395 | ||
8feae131 DH |
1396 | error_just_free: |
1397 | up_write(&nommu_region_sem); | |
1398 | error: | |
1399 | fput(region->vm_file); | |
1400 | kmem_cache_free(vm_region_jar, region); | |
1401 | fput(vma->vm_file); | |
1402 | if (vma->vm_flags & VM_EXECUTABLE) | |
1403 | removed_exe_file_vma(vma->vm_mm); | |
1404 | kmem_cache_free(vm_area_cachep, vma); | |
1405 | kleave(" = %d", ret); | |
1406 | return ret; | |
1407 | ||
1408 | sharing_violation: | |
1409 | up_write(&nommu_region_sem); | |
1410 | printk(KERN_WARNING "Attempt to share mismatched mappings\n"); | |
1411 | ret = -EINVAL; | |
1412 | goto error; | |
1da177e4 | 1413 | |
8feae131 DH |
1414 | error_getting_vma: |
1415 | kmem_cache_free(vm_region_jar, region); | |
1416 | printk(KERN_WARNING "Allocation of vma for %lu byte allocation" | |
1417 | " from process %d failed\n", | |
1da177e4 LT |
1418 | len, current->pid); |
1419 | show_free_areas(); | |
1420 | return -ENOMEM; | |
1421 | ||
8feae131 DH |
1422 | error_getting_region: |
1423 | printk(KERN_WARNING "Allocation of vm region for %lu byte allocation" | |
1424 | " from process %d failed\n", | |
1da177e4 LT |
1425 | len, current->pid); |
1426 | show_free_areas(); | |
1427 | return -ENOMEM; | |
1428 | } | |
b5073173 | 1429 | EXPORT_SYMBOL(do_mmap_pgoff); |
1da177e4 LT |
1430 | |
1431 | /* | |
8feae131 DH |
1432 | * split a vma into two pieces at address 'addr', a new vma is allocated either |
1433 | * for the first part or the tail. | |
1da177e4 | 1434 | */ |
8feae131 DH |
1435 | int split_vma(struct mm_struct *mm, struct vm_area_struct *vma, |
1436 | unsigned long addr, int new_below) | |
1da177e4 | 1437 | { |
8feae131 DH |
1438 | struct vm_area_struct *new; |
1439 | struct vm_region *region; | |
1440 | unsigned long npages; | |
1da177e4 | 1441 | |
8feae131 | 1442 | kenter(""); |
1da177e4 | 1443 | |
8feae131 DH |
1444 | /* we're only permitted to split anonymous regions that have a single |
1445 | * owner */ | |
1446 | if (vma->vm_file || | |
1447 | atomic_read(&vma->vm_region->vm_usage) != 1) | |
1448 | return -ENOMEM; | |
1da177e4 | 1449 | |
8feae131 DH |
1450 | if (mm->map_count >= sysctl_max_map_count) |
1451 | return -ENOMEM; | |
1da177e4 | 1452 | |
8feae131 DH |
1453 | region = kmem_cache_alloc(vm_region_jar, GFP_KERNEL); |
1454 | if (!region) | |
1455 | return -ENOMEM; | |
1da177e4 | 1456 | |
8feae131 DH |
1457 | new = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL); |
1458 | if (!new) { | |
1459 | kmem_cache_free(vm_region_jar, region); | |
1460 | return -ENOMEM; | |
1461 | } | |
1462 | ||
1463 | /* most fields are the same, copy all, and then fixup */ | |
1464 | *new = *vma; | |
1465 | *region = *vma->vm_region; | |
1466 | new->vm_region = region; | |
1467 | ||
1468 | npages = (addr - vma->vm_start) >> PAGE_SHIFT; | |
1469 | ||
1470 | if (new_below) { | |
dd8632a1 | 1471 | region->vm_top = region->vm_end = new->vm_end = addr; |
8feae131 DH |
1472 | } else { |
1473 | region->vm_start = new->vm_start = addr; | |
1474 | region->vm_pgoff = new->vm_pgoff += npages; | |
1da177e4 | 1475 | } |
8feae131 DH |
1476 | |
1477 | if (new->vm_ops && new->vm_ops->open) | |
1478 | new->vm_ops->open(new); | |
1479 | ||
1480 | delete_vma_from_mm(vma); | |
1481 | down_write(&nommu_region_sem); | |
1482 | delete_nommu_region(vma->vm_region); | |
1483 | if (new_below) { | |
1484 | vma->vm_region->vm_start = vma->vm_start = addr; | |
1485 | vma->vm_region->vm_pgoff = vma->vm_pgoff += npages; | |
1486 | } else { | |
1487 | vma->vm_region->vm_end = vma->vm_end = addr; | |
dd8632a1 | 1488 | vma->vm_region->vm_top = addr; |
8feae131 DH |
1489 | } |
1490 | add_nommu_region(vma->vm_region); | |
1491 | add_nommu_region(new->vm_region); | |
1492 | up_write(&nommu_region_sem); | |
1493 | add_vma_to_mm(mm, vma); | |
1494 | add_vma_to_mm(mm, new); | |
1495 | return 0; | |
1da177e4 LT |
1496 | } |
1497 | ||
3034097a | 1498 | /* |
8feae131 DH |
1499 | * shrink a VMA by removing the specified chunk from either the beginning or |
1500 | * the end | |
3034097a | 1501 | */ |
8feae131 DH |
1502 | static int shrink_vma(struct mm_struct *mm, |
1503 | struct vm_area_struct *vma, | |
1504 | unsigned long from, unsigned long to) | |
1da177e4 | 1505 | { |
8feae131 | 1506 | struct vm_region *region; |
1da177e4 | 1507 | |
8feae131 | 1508 | kenter(""); |
1da177e4 | 1509 | |
8feae131 DH |
1510 | /* adjust the VMA's pointers, which may reposition it in the MM's tree |
1511 | * and list */ | |
1512 | delete_vma_from_mm(vma); | |
1513 | if (from > vma->vm_start) | |
1514 | vma->vm_end = from; | |
1515 | else | |
1516 | vma->vm_start = to; | |
1517 | add_vma_to_mm(mm, vma); | |
1da177e4 | 1518 | |
8feae131 DH |
1519 | /* cut the backing region down to size */ |
1520 | region = vma->vm_region; | |
1521 | BUG_ON(atomic_read(®ion->vm_usage) != 1); | |
1522 | ||
1523 | down_write(&nommu_region_sem); | |
1524 | delete_nommu_region(region); | |
dd8632a1 PM |
1525 | if (from > region->vm_start) { |
1526 | to = region->vm_top; | |
1527 | region->vm_top = region->vm_end = from; | |
1528 | } else { | |
8feae131 | 1529 | region->vm_start = to; |
dd8632a1 | 1530 | } |
8feae131 DH |
1531 | add_nommu_region(region); |
1532 | up_write(&nommu_region_sem); | |
1533 | ||
1534 | free_page_series(from, to); | |
1535 | return 0; | |
1536 | } | |
1da177e4 | 1537 | |
8feae131 DH |
1538 | /* |
1539 | * release a mapping | |
1540 | * - under NOMMU conditions the chunk to be unmapped must be backed by a single | |
1541 | * VMA, though it need not cover the whole VMA | |
1542 | */ | |
1543 | int do_munmap(struct mm_struct *mm, unsigned long start, size_t len) | |
1544 | { | |
1545 | struct vm_area_struct *vma; | |
1546 | struct rb_node *rb; | |
1547 | unsigned long end = start + len; | |
1548 | int ret; | |
1da177e4 | 1549 | |
8feae131 | 1550 | kenter(",%lx,%zx", start, len); |
1da177e4 | 1551 | |
8feae131 DH |
1552 | if (len == 0) |
1553 | return -EINVAL; | |
365e9c87 | 1554 | |
8feae131 DH |
1555 | /* find the first potentially overlapping VMA */ |
1556 | vma = find_vma(mm, start); | |
1557 | if (!vma) { | |
33e5d769 DH |
1558 | static int limit = 0; |
1559 | if (limit < 5) { | |
1560 | printk(KERN_WARNING | |
1561 | "munmap of memory not mmapped by process %d" | |
1562 | " (%s): 0x%lx-0x%lx\n", | |
1563 | current->pid, current->comm, | |
1564 | start, start + len - 1); | |
1565 | limit++; | |
1566 | } | |
8feae131 DH |
1567 | return -EINVAL; |
1568 | } | |
1da177e4 | 1569 | |
8feae131 DH |
1570 | /* we're allowed to split an anonymous VMA but not a file-backed one */ |
1571 | if (vma->vm_file) { | |
1572 | do { | |
1573 | if (start > vma->vm_start) { | |
1574 | kleave(" = -EINVAL [miss]"); | |
1575 | return -EINVAL; | |
1576 | } | |
1577 | if (end == vma->vm_end) | |
1578 | goto erase_whole_vma; | |
1579 | rb = rb_next(&vma->vm_rb); | |
1580 | vma = rb_entry(rb, struct vm_area_struct, vm_rb); | |
1581 | } while (rb); | |
1582 | kleave(" = -EINVAL [split file]"); | |
1583 | return -EINVAL; | |
1584 | } else { | |
1585 | /* the chunk must be a subset of the VMA found */ | |
1586 | if (start == vma->vm_start && end == vma->vm_end) | |
1587 | goto erase_whole_vma; | |
1588 | if (start < vma->vm_start || end > vma->vm_end) { | |
1589 | kleave(" = -EINVAL [superset]"); | |
1590 | return -EINVAL; | |
1591 | } | |
1592 | if (start & ~PAGE_MASK) { | |
1593 | kleave(" = -EINVAL [unaligned start]"); | |
1594 | return -EINVAL; | |
1595 | } | |
1596 | if (end != vma->vm_end && end & ~PAGE_MASK) { | |
1597 | kleave(" = -EINVAL [unaligned split]"); | |
1598 | return -EINVAL; | |
1599 | } | |
1600 | if (start != vma->vm_start && end != vma->vm_end) { | |
1601 | ret = split_vma(mm, vma, start, 1); | |
1602 | if (ret < 0) { | |
1603 | kleave(" = %d [split]", ret); | |
1604 | return ret; | |
1605 | } | |
1606 | } | |
1607 | return shrink_vma(mm, vma, start, end); | |
1608 | } | |
1da177e4 | 1609 | |
8feae131 DH |
1610 | erase_whole_vma: |
1611 | delete_vma_from_mm(vma); | |
1612 | delete_vma(mm, vma); | |
1613 | kleave(" = 0"); | |
1da177e4 LT |
1614 | return 0; |
1615 | } | |
b5073173 | 1616 | EXPORT_SYMBOL(do_munmap); |
1da177e4 | 1617 | |
6a6160a7 | 1618 | SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len) |
3034097a DH |
1619 | { |
1620 | int ret; | |
1621 | struct mm_struct *mm = current->mm; | |
1622 | ||
1623 | down_write(&mm->mmap_sem); | |
1624 | ret = do_munmap(mm, addr, len); | |
1625 | up_write(&mm->mmap_sem); | |
1626 | return ret; | |
1627 | } | |
1628 | ||
1629 | /* | |
8feae131 | 1630 | * release all the mappings made in a process's VM space |
3034097a | 1631 | */ |
8feae131 | 1632 | void exit_mmap(struct mm_struct *mm) |
1da177e4 | 1633 | { |
8feae131 | 1634 | struct vm_area_struct *vma; |
1da177e4 | 1635 | |
8feae131 DH |
1636 | if (!mm) |
1637 | return; | |
1da177e4 | 1638 | |
8feae131 | 1639 | kenter(""); |
1da177e4 | 1640 | |
8feae131 | 1641 | mm->total_vm = 0; |
1da177e4 | 1642 | |
8feae131 DH |
1643 | while ((vma = mm->mmap)) { |
1644 | mm->mmap = vma->vm_next; | |
1645 | delete_vma_from_mm(vma); | |
1646 | delete_vma(mm, vma); | |
1da177e4 | 1647 | } |
8feae131 DH |
1648 | |
1649 | kleave(""); | |
1da177e4 LT |
1650 | } |
1651 | ||
1da177e4 LT |
1652 | unsigned long do_brk(unsigned long addr, unsigned long len) |
1653 | { | |
1654 | return -ENOMEM; | |
1655 | } | |
1656 | ||
1657 | /* | |
6fa5f80b DH |
1658 | * expand (or shrink) an existing mapping, potentially moving it at the same |
1659 | * time (controlled by the MREMAP_MAYMOVE flag and available VM space) | |
1da177e4 | 1660 | * |
6fa5f80b | 1661 | * under NOMMU conditions, we only permit changing a mapping's size, and only |
8feae131 DH |
1662 | * as long as it stays within the region allocated by do_mmap_private() and the |
1663 | * block is not shareable | |
1da177e4 | 1664 | * |
6fa5f80b | 1665 | * MREMAP_FIXED is not supported under NOMMU conditions |
1da177e4 LT |
1666 | */ |
1667 | unsigned long do_mremap(unsigned long addr, | |
1668 | unsigned long old_len, unsigned long new_len, | |
1669 | unsigned long flags, unsigned long new_addr) | |
1670 | { | |
6fa5f80b | 1671 | struct vm_area_struct *vma; |
1da177e4 LT |
1672 | |
1673 | /* insanity checks first */ | |
8feae131 | 1674 | if (old_len == 0 || new_len == 0) |
1da177e4 LT |
1675 | return (unsigned long) -EINVAL; |
1676 | ||
8feae131 DH |
1677 | if (addr & ~PAGE_MASK) |
1678 | return -EINVAL; | |
1679 | ||
1da177e4 LT |
1680 | if (flags & MREMAP_FIXED && new_addr != addr) |
1681 | return (unsigned long) -EINVAL; | |
1682 | ||
8feae131 | 1683 | vma = find_vma_exact(current->mm, addr, old_len); |
6fa5f80b DH |
1684 | if (!vma) |
1685 | return (unsigned long) -EINVAL; | |
1da177e4 | 1686 | |
6fa5f80b | 1687 | if (vma->vm_end != vma->vm_start + old_len) |
1da177e4 LT |
1688 | return (unsigned long) -EFAULT; |
1689 | ||
6fa5f80b | 1690 | if (vma->vm_flags & VM_MAYSHARE) |
1da177e4 LT |
1691 | return (unsigned long) -EPERM; |
1692 | ||
8feae131 | 1693 | if (new_len > vma->vm_region->vm_end - vma->vm_region->vm_start) |
1da177e4 LT |
1694 | return (unsigned long) -ENOMEM; |
1695 | ||
1696 | /* all checks complete - do it */ | |
6fa5f80b | 1697 | vma->vm_end = vma->vm_start + new_len; |
6fa5f80b DH |
1698 | return vma->vm_start; |
1699 | } | |
b5073173 | 1700 | EXPORT_SYMBOL(do_mremap); |
6fa5f80b | 1701 | |
6a6160a7 HC |
1702 | SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, |
1703 | unsigned long, new_len, unsigned long, flags, | |
1704 | unsigned long, new_addr) | |
6fa5f80b DH |
1705 | { |
1706 | unsigned long ret; | |
1707 | ||
1708 | down_write(¤t->mm->mmap_sem); | |
1709 | ret = do_mremap(addr, old_len, new_len, flags, new_addr); | |
1710 | up_write(¤t->mm->mmap_sem); | |
1711 | return ret; | |
1da177e4 LT |
1712 | } |
1713 | ||
6aab341e | 1714 | struct page *follow_page(struct vm_area_struct *vma, unsigned long address, |
deceb6cd | 1715 | unsigned int foll_flags) |
1da177e4 LT |
1716 | { |
1717 | return NULL; | |
1718 | } | |
1719 | ||
1da177e4 LT |
1720 | int remap_pfn_range(struct vm_area_struct *vma, unsigned long from, |
1721 | unsigned long to, unsigned long size, pgprot_t prot) | |
1722 | { | |
66aa2b4b GU |
1723 | vma->vm_start = vma->vm_pgoff << PAGE_SHIFT; |
1724 | return 0; | |
1da177e4 | 1725 | } |
22c4af40 | 1726 | EXPORT_SYMBOL(remap_pfn_range); |
1da177e4 | 1727 | |
f905bc44 PM |
1728 | int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, |
1729 | unsigned long pgoff) | |
1730 | { | |
1731 | unsigned int size = vma->vm_end - vma->vm_start; | |
1732 | ||
1733 | if (!(vma->vm_flags & VM_USERMAP)) | |
1734 | return -EINVAL; | |
1735 | ||
1736 | vma->vm_start = (unsigned long)(addr + (pgoff << PAGE_SHIFT)); | |
1737 | vma->vm_end = vma->vm_start + size; | |
1738 | ||
1739 | return 0; | |
1740 | } | |
1741 | EXPORT_SYMBOL(remap_vmalloc_range); | |
1742 | ||
1da177e4 LT |
1743 | void swap_unplug_io_fn(struct backing_dev_info *bdi, struct page *page) |
1744 | { | |
1745 | } | |
1746 | ||
1747 | unsigned long arch_get_unmapped_area(struct file *file, unsigned long addr, | |
1748 | unsigned long len, unsigned long pgoff, unsigned long flags) | |
1749 | { | |
1750 | return -ENOMEM; | |
1751 | } | |
1752 | ||
1363c3cd | 1753 | void arch_unmap_area(struct mm_struct *mm, unsigned long addr) |
1da177e4 LT |
1754 | { |
1755 | } | |
1756 | ||
1da177e4 LT |
1757 | void unmap_mapping_range(struct address_space *mapping, |
1758 | loff_t const holebegin, loff_t const holelen, | |
1759 | int even_cows) | |
1760 | { | |
1761 | } | |
22c4af40 | 1762 | EXPORT_SYMBOL(unmap_mapping_range); |
1da177e4 | 1763 | |
d56e03cd DH |
1764 | /* |
1765 | * ask for an unmapped area at which to create a mapping on a file | |
1766 | */ | |
1767 | unsigned long get_unmapped_area(struct file *file, unsigned long addr, | |
1768 | unsigned long len, unsigned long pgoff, | |
1769 | unsigned long flags) | |
1770 | { | |
1771 | unsigned long (*get_area)(struct file *, unsigned long, unsigned long, | |
1772 | unsigned long, unsigned long); | |
1773 | ||
1774 | get_area = current->mm->get_unmapped_area; | |
1775 | if (file && file->f_op && file->f_op->get_unmapped_area) | |
1776 | get_area = file->f_op->get_unmapped_area; | |
1777 | ||
1778 | if (!get_area) | |
1779 | return -ENOSYS; | |
1780 | ||
1781 | return get_area(file, addr, len, pgoff, flags); | |
1782 | } | |
d56e03cd DH |
1783 | EXPORT_SYMBOL(get_unmapped_area); |
1784 | ||
1da177e4 LT |
1785 | /* |
1786 | * Check that a process has enough memory to allocate a new virtual | |
1787 | * mapping. 0 means there is enough memory for the allocation to | |
1788 | * succeed and -ENOMEM implies there is not. | |
1789 | * | |
1790 | * We currently support three overcommit policies, which are set via the | |
1791 | * vm.overcommit_memory sysctl. See Documentation/vm/overcommit-accounting | |
1792 | * | |
1793 | * Strict overcommit modes added 2002 Feb 26 by Alan Cox. | |
1794 | * Additional code 2002 Jul 20 by Robert Love. | |
1795 | * | |
1796 | * cap_sys_admin is 1 if the process has admin privileges, 0 otherwise. | |
1797 | * | |
1798 | * Note this is a helper function intended to be used by LSMs which | |
1799 | * wish to use this logic. | |
1800 | */ | |
34b4e4aa | 1801 | int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin) |
1da177e4 LT |
1802 | { |
1803 | unsigned long free, allowed; | |
1804 | ||
1805 | vm_acct_memory(pages); | |
1806 | ||
1807 | /* | |
1808 | * Sometimes we want to use more memory than we have | |
1809 | */ | |
1810 | if (sysctl_overcommit_memory == OVERCOMMIT_ALWAYS) | |
1811 | return 0; | |
1812 | ||
1813 | if (sysctl_overcommit_memory == OVERCOMMIT_GUESS) { | |
1814 | unsigned long n; | |
1815 | ||
347ce434 | 1816 | free = global_page_state(NR_FILE_PAGES); |
1da177e4 LT |
1817 | free += nr_swap_pages; |
1818 | ||
1819 | /* | |
1820 | * Any slabs which are created with the | |
1821 | * SLAB_RECLAIM_ACCOUNT flag claim to have contents | |
1822 | * which are reclaimable, under pressure. The dentry | |
1823 | * cache and most inode caches should fall into this | |
1824 | */ | |
972d1a7b | 1825 | free += global_page_state(NR_SLAB_RECLAIMABLE); |
1da177e4 LT |
1826 | |
1827 | /* | |
1828 | * Leave the last 3% for root | |
1829 | */ | |
1830 | if (!cap_sys_admin) | |
1831 | free -= free / 32; | |
1832 | ||
1833 | if (free > pages) | |
1834 | return 0; | |
1835 | ||
1836 | /* | |
1837 | * nr_free_pages() is very expensive on large systems, | |
1838 | * only call if we're about to fail. | |
1839 | */ | |
1840 | n = nr_free_pages(); | |
d5ddc79b HA |
1841 | |
1842 | /* | |
1843 | * Leave reserved pages. The pages are not for anonymous pages. | |
1844 | */ | |
1845 | if (n <= totalreserve_pages) | |
1846 | goto error; | |
1847 | else | |
1848 | n -= totalreserve_pages; | |
1849 | ||
1850 | /* | |
1851 | * Leave the last 3% for root | |
1852 | */ | |
1da177e4 LT |
1853 | if (!cap_sys_admin) |
1854 | n -= n / 32; | |
1855 | free += n; | |
1856 | ||
1857 | if (free > pages) | |
1858 | return 0; | |
d5ddc79b HA |
1859 | |
1860 | goto error; | |
1da177e4 LT |
1861 | } |
1862 | ||
1863 | allowed = totalram_pages * sysctl_overcommit_ratio / 100; | |
1864 | /* | |
1865 | * Leave the last 3% for root | |
1866 | */ | |
1867 | if (!cap_sys_admin) | |
1868 | allowed -= allowed / 32; | |
1869 | allowed += total_swap_pages; | |
1870 | ||
1871 | /* Don't let a single process grow too big: | |
1872 | leave 3% of the size of this process for other processes */ | |
731572d3 AC |
1873 | if (mm) |
1874 | allowed -= mm->total_vm / 32; | |
1da177e4 | 1875 | |
00a62ce9 | 1876 | if (percpu_counter_read_positive(&vm_committed_as) < allowed) |
1da177e4 | 1877 | return 0; |
00a62ce9 | 1878 | |
d5ddc79b | 1879 | error: |
1da177e4 LT |
1880 | vm_unacct_memory(pages); |
1881 | ||
1882 | return -ENOMEM; | |
1883 | } | |
1884 | ||
1885 | int in_gate_area_no_task(unsigned long addr) | |
1886 | { | |
1887 | return 0; | |
1888 | } | |
b0e15190 | 1889 | |
d0217ac0 | 1890 | int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
b0e15190 DH |
1891 | { |
1892 | BUG(); | |
d0217ac0 | 1893 | return 0; |
b0e15190 | 1894 | } |
b5073173 | 1895 | EXPORT_SYMBOL(filemap_fault); |
0ec76a11 DH |
1896 | |
1897 | /* | |
1898 | * Access another process' address space. | |
1899 | * - source/target buffer must be kernel space | |
1900 | */ | |
1901 | int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write) | |
1902 | { | |
0ec76a11 DH |
1903 | struct vm_area_struct *vma; |
1904 | struct mm_struct *mm; | |
1905 | ||
1906 | if (addr + len < addr) | |
1907 | return 0; | |
1908 | ||
1909 | mm = get_task_mm(tsk); | |
1910 | if (!mm) | |
1911 | return 0; | |
1912 | ||
1913 | down_read(&mm->mmap_sem); | |
1914 | ||
1915 | /* the access must start within one of the target process's mappings */ | |
0159b141 DH |
1916 | vma = find_vma(mm, addr); |
1917 | if (vma) { | |
0ec76a11 DH |
1918 | /* don't overrun this mapping */ |
1919 | if (addr + len >= vma->vm_end) | |
1920 | len = vma->vm_end - addr; | |
1921 | ||
1922 | /* only read or write mappings where it is permitted */ | |
d00c7b99 | 1923 | if (write && vma->vm_flags & VM_MAYWRITE) |
0ec76a11 | 1924 | len -= copy_to_user((void *) addr, buf, len); |
d00c7b99 | 1925 | else if (!write && vma->vm_flags & VM_MAYREAD) |
0ec76a11 DH |
1926 | len -= copy_from_user(buf, (void *) addr, len); |
1927 | else | |
1928 | len = 0; | |
1929 | } else { | |
1930 | len = 0; | |
1931 | } | |
1932 | ||
1933 | up_read(&mm->mmap_sem); | |
1934 | mmput(mm); | |
1935 | return len; | |
1936 | } |