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 LT |
58 | |
59 | void *high_memory; | |
60 | struct page *mem_map; | |
61 | unsigned long max_mapnr; | |
62 | unsigned long num_physpages; | |
00a62ce9 | 63 | struct percpu_counter vm_committed_as; |
1da177e4 LT |
64 | int sysctl_overcommit_memory = OVERCOMMIT_GUESS; /* heuristic overcommit */ |
65 | int sysctl_overcommit_ratio = 50; /* default is 50% */ | |
66 | int sysctl_max_map_count = DEFAULT_MAX_MAP_COUNT; | |
fc4d5c29 | 67 | int sysctl_nr_trim_pages = CONFIG_NOMMU_INITIAL_TRIM_EXCESS; |
1da177e4 LT |
68 | int heap_stack_gap = 0; |
69 | ||
33e5d769 | 70 | atomic_long_t mmap_pages_allocated; |
8feae131 | 71 | |
1da177e4 | 72 | EXPORT_SYMBOL(mem_map); |
6a04de6d | 73 | EXPORT_SYMBOL(num_physpages); |
1da177e4 | 74 | |
8feae131 DH |
75 | /* list of mapped, potentially shareable regions */ |
76 | static struct kmem_cache *vm_region_jar; | |
77 | struct rb_root nommu_region_tree = RB_ROOT; | |
78 | DECLARE_RWSEM(nommu_region_sem); | |
1da177e4 LT |
79 | |
80 | struct vm_operations_struct generic_file_vm_ops = { | |
81 | }; | |
82 | ||
83 | /* | |
84 | * Handle all mappings that got truncated by a "truncate()" | |
85 | * system call. | |
86 | * | |
87 | * NOTE! We have to be ready to update the memory sharing | |
88 | * between the file and the memory map for a potential last | |
89 | * incomplete page. Ugly, but necessary. | |
90 | */ | |
91 | int vmtruncate(struct inode *inode, loff_t offset) | |
92 | { | |
93 | struct address_space *mapping = inode->i_mapping; | |
94 | unsigned long limit; | |
95 | ||
96 | if (inode->i_size < offset) | |
97 | goto do_expand; | |
98 | i_size_write(inode, offset); | |
99 | ||
100 | truncate_inode_pages(mapping, offset); | |
101 | goto out_truncate; | |
102 | ||
103 | do_expand: | |
104 | limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur; | |
105 | if (limit != RLIM_INFINITY && offset > limit) | |
106 | goto out_sig; | |
107 | if (offset > inode->i_sb->s_maxbytes) | |
108 | goto out; | |
109 | i_size_write(inode, offset); | |
110 | ||
111 | out_truncate: | |
acfa4380 | 112 | if (inode->i_op->truncate) |
1da177e4 LT |
113 | inode->i_op->truncate(inode); |
114 | return 0; | |
115 | out_sig: | |
116 | send_sig(SIGXFSZ, current, 0); | |
117 | out: | |
118 | return -EFBIG; | |
119 | } | |
120 | ||
121 | EXPORT_SYMBOL(vmtruncate); | |
122 | ||
123 | /* | |
124 | * Return the total memory allocated for this pointer, not | |
125 | * just what the caller asked for. | |
126 | * | |
127 | * Doesn't have to be accurate, i.e. may have races. | |
128 | */ | |
129 | unsigned int kobjsize(const void *objp) | |
130 | { | |
131 | struct page *page; | |
132 | ||
4016a139 MH |
133 | /* |
134 | * If the object we have should not have ksize performed on it, | |
135 | * return size of 0 | |
136 | */ | |
5a1603be | 137 | if (!objp || !virt_addr_valid(objp)) |
6cfd53fc PM |
138 | return 0; |
139 | ||
140 | page = virt_to_head_page(objp); | |
6cfd53fc PM |
141 | |
142 | /* | |
143 | * If the allocator sets PageSlab, we know the pointer came from | |
144 | * kmalloc(). | |
145 | */ | |
1da177e4 LT |
146 | if (PageSlab(page)) |
147 | return ksize(objp); | |
148 | ||
ab2e83ea PM |
149 | /* |
150 | * If it's not a compound page, see if we have a matching VMA | |
151 | * region. This test is intentionally done in reverse order, | |
152 | * so if there's no VMA, we still fall through and hand back | |
153 | * PAGE_SIZE for 0-order pages. | |
154 | */ | |
155 | if (!PageCompound(page)) { | |
156 | struct vm_area_struct *vma; | |
157 | ||
158 | vma = find_vma(current->mm, (unsigned long)objp); | |
159 | if (vma) | |
160 | return vma->vm_end - vma->vm_start; | |
161 | } | |
162 | ||
6cfd53fc PM |
163 | /* |
164 | * The ksize() function is only guaranteed to work for pointers | |
5a1603be | 165 | * returned by kmalloc(). So handle arbitrary pointers here. |
6cfd53fc | 166 | */ |
5a1603be | 167 | return PAGE_SIZE << compound_order(page); |
1da177e4 LT |
168 | } |
169 | ||
b291f000 | 170 | int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, |
9d73777e PZ |
171 | unsigned long start, int nr_pages, int flags, |
172 | struct page **pages, struct vm_area_struct **vmas) | |
1da177e4 | 173 | { |
910e46da | 174 | struct vm_area_struct *vma; |
7b4d5b8b DH |
175 | unsigned long vm_flags; |
176 | int i; | |
b291f000 NP |
177 | int write = !!(flags & GUP_FLAGS_WRITE); |
178 | int force = !!(flags & GUP_FLAGS_FORCE); | |
7b4d5b8b DH |
179 | |
180 | /* calculate required read or write permissions. | |
181 | * - if 'force' is set, we only require the "MAY" flags. | |
182 | */ | |
183 | vm_flags = write ? (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD); | |
184 | vm_flags &= force ? (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE); | |
1da177e4 | 185 | |
9d73777e | 186 | for (i = 0; i < nr_pages; i++) { |
910e46da | 187 | vma = find_vma(mm, start); |
7b4d5b8b DH |
188 | if (!vma) |
189 | goto finish_or_fault; | |
190 | ||
191 | /* protect what we can, including chardevs */ | |
1c3aff1c HD |
192 | if ((vma->vm_flags & (VM_IO | VM_PFNMAP)) || |
193 | !(vm_flags & vma->vm_flags)) | |
7b4d5b8b | 194 | goto finish_or_fault; |
910e46da | 195 | |
1da177e4 LT |
196 | if (pages) { |
197 | pages[i] = virt_to_page(start); | |
198 | if (pages[i]) | |
199 | page_cache_get(pages[i]); | |
200 | } | |
201 | if (vmas) | |
910e46da | 202 | vmas[i] = vma; |
1da177e4 LT |
203 | start += PAGE_SIZE; |
204 | } | |
7b4d5b8b DH |
205 | |
206 | return i; | |
207 | ||
208 | finish_or_fault: | |
209 | return i ? : -EFAULT; | |
1da177e4 | 210 | } |
b291f000 | 211 | |
b291f000 NP |
212 | /* |
213 | * get a list of pages in an address range belonging to the specified process | |
214 | * and indicate the VMA that covers each page | |
215 | * - this is potentially dodgy as we may end incrementing the page count of a | |
216 | * slab page or a secondary page from a compound page | |
217 | * - don't permit access to VMAs that don't support it, such as I/O mappings | |
218 | */ | |
219 | int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, | |
9d73777e | 220 | unsigned long start, int nr_pages, int write, int force, |
b291f000 NP |
221 | struct page **pages, struct vm_area_struct **vmas) |
222 | { | |
223 | int flags = 0; | |
224 | ||
225 | if (write) | |
226 | flags |= GUP_FLAGS_WRITE; | |
227 | if (force) | |
228 | flags |= GUP_FLAGS_FORCE; | |
229 | ||
9d73777e | 230 | return __get_user_pages(tsk, mm, start, nr_pages, flags, pages, vmas); |
b291f000 | 231 | } |
66aa2b4b GU |
232 | EXPORT_SYMBOL(get_user_pages); |
233 | ||
dfc2f91a PM |
234 | /** |
235 | * follow_pfn - look up PFN at a user virtual address | |
236 | * @vma: memory mapping | |
237 | * @address: user virtual address | |
238 | * @pfn: location to store found PFN | |
239 | * | |
240 | * Only IO mappings and raw PFN mappings are allowed. | |
241 | * | |
242 | * Returns zero and the pfn at @pfn on success, -ve otherwise. | |
243 | */ | |
244 | int follow_pfn(struct vm_area_struct *vma, unsigned long address, | |
245 | unsigned long *pfn) | |
246 | { | |
247 | if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) | |
248 | return -EINVAL; | |
249 | ||
250 | *pfn = address >> PAGE_SHIFT; | |
251 | return 0; | |
252 | } | |
253 | EXPORT_SYMBOL(follow_pfn); | |
254 | ||
1da177e4 LT |
255 | DEFINE_RWLOCK(vmlist_lock); |
256 | struct vm_struct *vmlist; | |
257 | ||
b3bdda02 | 258 | void vfree(const void *addr) |
1da177e4 LT |
259 | { |
260 | kfree(addr); | |
261 | } | |
b5073173 | 262 | EXPORT_SYMBOL(vfree); |
1da177e4 | 263 | |
dd0fc66f | 264 | void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot) |
1da177e4 LT |
265 | { |
266 | /* | |
8518609d RD |
267 | * You can't specify __GFP_HIGHMEM with kmalloc() since kmalloc() |
268 | * returns only a logical address. | |
1da177e4 | 269 | */ |
84097518 | 270 | return kmalloc(size, (gfp_mask | __GFP_COMP) & ~__GFP_HIGHMEM); |
1da177e4 | 271 | } |
b5073173 | 272 | EXPORT_SYMBOL(__vmalloc); |
1da177e4 | 273 | |
f905bc44 PM |
274 | void *vmalloc_user(unsigned long size) |
275 | { | |
276 | void *ret; | |
277 | ||
278 | ret = __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO, | |
279 | PAGE_KERNEL); | |
280 | if (ret) { | |
281 | struct vm_area_struct *vma; | |
282 | ||
283 | down_write(¤t->mm->mmap_sem); | |
284 | vma = find_vma(current->mm, (unsigned long)ret); | |
285 | if (vma) | |
286 | vma->vm_flags |= VM_USERMAP; | |
287 | up_write(¤t->mm->mmap_sem); | |
288 | } | |
289 | ||
290 | return ret; | |
291 | } | |
292 | EXPORT_SYMBOL(vmalloc_user); | |
293 | ||
b3bdda02 | 294 | struct page *vmalloc_to_page(const void *addr) |
1da177e4 LT |
295 | { |
296 | return virt_to_page(addr); | |
297 | } | |
b5073173 | 298 | EXPORT_SYMBOL(vmalloc_to_page); |
1da177e4 | 299 | |
b3bdda02 | 300 | unsigned long vmalloc_to_pfn(const void *addr) |
1da177e4 LT |
301 | { |
302 | return page_to_pfn(virt_to_page(addr)); | |
303 | } | |
b5073173 | 304 | EXPORT_SYMBOL(vmalloc_to_pfn); |
1da177e4 LT |
305 | |
306 | long vread(char *buf, char *addr, unsigned long count) | |
307 | { | |
308 | memcpy(buf, addr, count); | |
309 | return count; | |
310 | } | |
311 | ||
312 | long vwrite(char *buf, char *addr, unsigned long count) | |
313 | { | |
314 | /* Don't allow overflow */ | |
315 | if ((unsigned long) addr + count < count) | |
316 | count = -(unsigned long) addr; | |
317 | ||
318 | memcpy(addr, buf, count); | |
319 | return(count); | |
320 | } | |
321 | ||
322 | /* | |
323 | * vmalloc - allocate virtually continguos memory | |
324 | * | |
325 | * @size: allocation size | |
326 | * | |
327 | * Allocate enough pages to cover @size from the page level | |
328 | * allocator and map them into continguos kernel virtual space. | |
329 | * | |
c1c8897f | 330 | * For tight control over page level allocator and protection flags |
1da177e4 LT |
331 | * use __vmalloc() instead. |
332 | */ | |
333 | void *vmalloc(unsigned long size) | |
334 | { | |
335 | return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL); | |
336 | } | |
f6138882 AM |
337 | EXPORT_SYMBOL(vmalloc); |
338 | ||
339 | void *vmalloc_node(unsigned long size, int node) | |
340 | { | |
341 | return vmalloc(size); | |
342 | } | |
343 | EXPORT_SYMBOL(vmalloc_node); | |
1da177e4 | 344 | |
1af446ed PM |
345 | #ifndef PAGE_KERNEL_EXEC |
346 | # define PAGE_KERNEL_EXEC PAGE_KERNEL | |
347 | #endif | |
348 | ||
349 | /** | |
350 | * vmalloc_exec - allocate virtually contiguous, executable memory | |
351 | * @size: allocation size | |
352 | * | |
353 | * Kernel-internal function to allocate enough pages to cover @size | |
354 | * the page level allocator and map them into contiguous and | |
355 | * executable kernel virtual space. | |
356 | * | |
357 | * For tight control over page level allocator and protection flags | |
358 | * use __vmalloc() instead. | |
359 | */ | |
360 | ||
361 | void *vmalloc_exec(unsigned long size) | |
362 | { | |
363 | return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC); | |
364 | } | |
365 | ||
b5073173 PM |
366 | /** |
367 | * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) | |
1da177e4 LT |
368 | * @size: allocation size |
369 | * | |
370 | * Allocate enough 32bit PA addressable pages to cover @size from the | |
371 | * page level allocator and map them into continguos kernel virtual space. | |
372 | */ | |
373 | void *vmalloc_32(unsigned long size) | |
374 | { | |
375 | return __vmalloc(size, GFP_KERNEL, PAGE_KERNEL); | |
376 | } | |
b5073173 PM |
377 | EXPORT_SYMBOL(vmalloc_32); |
378 | ||
379 | /** | |
380 | * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory | |
381 | * @size: allocation size | |
382 | * | |
383 | * The resulting memory area is 32bit addressable and zeroed so it can be | |
384 | * mapped to userspace without leaking data. | |
f905bc44 PM |
385 | * |
386 | * VM_USERMAP is set on the corresponding VMA so that subsequent calls to | |
387 | * remap_vmalloc_range() are permissible. | |
b5073173 PM |
388 | */ |
389 | void *vmalloc_32_user(unsigned long size) | |
390 | { | |
f905bc44 PM |
391 | /* |
392 | * We'll have to sort out the ZONE_DMA bits for 64-bit, | |
393 | * but for now this can simply use vmalloc_user() directly. | |
394 | */ | |
395 | return vmalloc_user(size); | |
b5073173 PM |
396 | } |
397 | EXPORT_SYMBOL(vmalloc_32_user); | |
1da177e4 LT |
398 | |
399 | void *vmap(struct page **pages, unsigned int count, unsigned long flags, pgprot_t prot) | |
400 | { | |
401 | BUG(); | |
402 | return NULL; | |
403 | } | |
b5073173 | 404 | EXPORT_SYMBOL(vmap); |
1da177e4 | 405 | |
b3bdda02 | 406 | void vunmap(const void *addr) |
1da177e4 LT |
407 | { |
408 | BUG(); | |
409 | } | |
b5073173 | 410 | EXPORT_SYMBOL(vunmap); |
1da177e4 | 411 | |
eb6434d9 PM |
412 | void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot) |
413 | { | |
414 | BUG(); | |
415 | return NULL; | |
416 | } | |
417 | EXPORT_SYMBOL(vm_map_ram); | |
418 | ||
419 | void vm_unmap_ram(const void *mem, unsigned int count) | |
420 | { | |
421 | BUG(); | |
422 | } | |
423 | EXPORT_SYMBOL(vm_unmap_ram); | |
424 | ||
425 | void vm_unmap_aliases(void) | |
426 | { | |
427 | } | |
428 | EXPORT_SYMBOL_GPL(vm_unmap_aliases); | |
429 | ||
1eeb66a1 CH |
430 | /* |
431 | * Implement a stub for vmalloc_sync_all() if the architecture chose not to | |
432 | * have one. | |
433 | */ | |
434 | void __attribute__((weak)) vmalloc_sync_all(void) | |
435 | { | |
436 | } | |
437 | ||
b5073173 PM |
438 | int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, |
439 | struct page *page) | |
440 | { | |
441 | return -EINVAL; | |
442 | } | |
443 | EXPORT_SYMBOL(vm_insert_page); | |
444 | ||
1da177e4 LT |
445 | /* |
446 | * sys_brk() for the most part doesn't need the global kernel | |
447 | * lock, except when an application is doing something nasty | |
448 | * like trying to un-brk an area that has already been mapped | |
449 | * to a regular file. in this case, the unmapping will need | |
450 | * to invoke file system routines that need the global lock. | |
451 | */ | |
6a6160a7 | 452 | SYSCALL_DEFINE1(brk, unsigned long, brk) |
1da177e4 LT |
453 | { |
454 | struct mm_struct *mm = current->mm; | |
455 | ||
456 | if (brk < mm->start_brk || brk > mm->context.end_brk) | |
457 | return mm->brk; | |
458 | ||
459 | if (mm->brk == brk) | |
460 | return mm->brk; | |
461 | ||
462 | /* | |
463 | * Always allow shrinking brk | |
464 | */ | |
465 | if (brk <= mm->brk) { | |
466 | mm->brk = brk; | |
467 | return brk; | |
468 | } | |
469 | ||
470 | /* | |
471 | * Ok, looks good - let it rip. | |
472 | */ | |
473 | return mm->brk = brk; | |
474 | } | |
475 | ||
8feae131 DH |
476 | /* |
477 | * initialise the VMA and region record slabs | |
478 | */ | |
479 | void __init mmap_init(void) | |
1da177e4 | 480 | { |
00a62ce9 KM |
481 | int ret; |
482 | ||
483 | ret = percpu_counter_init(&vm_committed_as, 0); | |
484 | VM_BUG_ON(ret); | |
33e5d769 | 485 | vm_region_jar = KMEM_CACHE(vm_region, SLAB_PANIC); |
1da177e4 | 486 | } |
1da177e4 | 487 | |
3034097a | 488 | /* |
8feae131 DH |
489 | * validate the region tree |
490 | * - the caller must hold the region lock | |
3034097a | 491 | */ |
8feae131 DH |
492 | #ifdef CONFIG_DEBUG_NOMMU_REGIONS |
493 | static noinline void validate_nommu_regions(void) | |
3034097a | 494 | { |
8feae131 DH |
495 | struct vm_region *region, *last; |
496 | struct rb_node *p, *lastp; | |
3034097a | 497 | |
8feae131 DH |
498 | lastp = rb_first(&nommu_region_tree); |
499 | if (!lastp) | |
500 | return; | |
501 | ||
502 | last = rb_entry(lastp, struct vm_region, vm_rb); | |
33e5d769 DH |
503 | BUG_ON(unlikely(last->vm_end <= last->vm_start)); |
504 | BUG_ON(unlikely(last->vm_top < last->vm_end)); | |
8feae131 DH |
505 | |
506 | while ((p = rb_next(lastp))) { | |
507 | region = rb_entry(p, struct vm_region, vm_rb); | |
508 | last = rb_entry(lastp, struct vm_region, vm_rb); | |
509 | ||
33e5d769 DH |
510 | BUG_ON(unlikely(region->vm_end <= region->vm_start)); |
511 | BUG_ON(unlikely(region->vm_top < region->vm_end)); | |
512 | BUG_ON(unlikely(region->vm_start < last->vm_top)); | |
3034097a | 513 | |
8feae131 DH |
514 | lastp = p; |
515 | } | |
3034097a | 516 | } |
8feae131 | 517 | #else |
33e5d769 DH |
518 | static void validate_nommu_regions(void) |
519 | { | |
520 | } | |
8feae131 | 521 | #endif |
3034097a DH |
522 | |
523 | /* | |
8feae131 | 524 | * add a region into the global tree |
3034097a | 525 | */ |
8feae131 | 526 | static void add_nommu_region(struct vm_region *region) |
3034097a | 527 | { |
8feae131 DH |
528 | struct vm_region *pregion; |
529 | struct rb_node **p, *parent; | |
3034097a | 530 | |
8feae131 DH |
531 | validate_nommu_regions(); |
532 | ||
8feae131 DH |
533 | parent = NULL; |
534 | p = &nommu_region_tree.rb_node; | |
535 | while (*p) { | |
536 | parent = *p; | |
537 | pregion = rb_entry(parent, struct vm_region, vm_rb); | |
538 | if (region->vm_start < pregion->vm_start) | |
539 | p = &(*p)->rb_left; | |
540 | else if (region->vm_start > pregion->vm_start) | |
541 | p = &(*p)->rb_right; | |
542 | else if (pregion == region) | |
543 | return; | |
544 | else | |
545 | BUG(); | |
3034097a DH |
546 | } |
547 | ||
8feae131 DH |
548 | rb_link_node(®ion->vm_rb, parent, p); |
549 | rb_insert_color(®ion->vm_rb, &nommu_region_tree); | |
3034097a | 550 | |
8feae131 | 551 | validate_nommu_regions(); |
3034097a | 552 | } |
3034097a | 553 | |
930e652a | 554 | /* |
8feae131 | 555 | * delete a region from the global tree |
930e652a | 556 | */ |
8feae131 | 557 | static void delete_nommu_region(struct vm_region *region) |
930e652a | 558 | { |
8feae131 | 559 | BUG_ON(!nommu_region_tree.rb_node); |
930e652a | 560 | |
8feae131 DH |
561 | validate_nommu_regions(); |
562 | rb_erase(®ion->vm_rb, &nommu_region_tree); | |
563 | validate_nommu_regions(); | |
57c8f63e GU |
564 | } |
565 | ||
6fa5f80b | 566 | /* |
8feae131 | 567 | * free a contiguous series of pages |
6fa5f80b | 568 | */ |
8feae131 | 569 | static void free_page_series(unsigned long from, unsigned long to) |
6fa5f80b | 570 | { |
8feae131 DH |
571 | for (; from < to; from += PAGE_SIZE) { |
572 | struct page *page = virt_to_page(from); | |
573 | ||
574 | kdebug("- free %lx", from); | |
33e5d769 | 575 | atomic_long_dec(&mmap_pages_allocated); |
8feae131 | 576 | if (page_count(page) != 1) |
33e5d769 DH |
577 | kdebug("free page %p: refcount not one: %d", |
578 | page, page_count(page)); | |
8feae131 | 579 | put_page(page); |
6fa5f80b | 580 | } |
6fa5f80b DH |
581 | } |
582 | ||
3034097a | 583 | /* |
8feae131 | 584 | * release a reference to a region |
33e5d769 | 585 | * - the caller must hold the region semaphore for writing, which this releases |
dd8632a1 | 586 | * - the region may not have been added to the tree yet, in which case vm_top |
8feae131 | 587 | * will equal vm_start |
3034097a | 588 | */ |
8feae131 DH |
589 | static void __put_nommu_region(struct vm_region *region) |
590 | __releases(nommu_region_sem) | |
1da177e4 | 591 | { |
8feae131 | 592 | kenter("%p{%d}", region, atomic_read(®ion->vm_usage)); |
1da177e4 | 593 | |
8feae131 | 594 | BUG_ON(!nommu_region_tree.rb_node); |
1da177e4 | 595 | |
8feae131 | 596 | if (atomic_dec_and_test(®ion->vm_usage)) { |
dd8632a1 | 597 | if (region->vm_top > region->vm_start) |
8feae131 DH |
598 | delete_nommu_region(region); |
599 | up_write(&nommu_region_sem); | |
600 | ||
601 | if (region->vm_file) | |
602 | fput(region->vm_file); | |
603 | ||
604 | /* IO memory and memory shared directly out of the pagecache | |
605 | * from ramfs/tmpfs mustn't be released here */ | |
606 | if (region->vm_flags & VM_MAPPED_COPY) { | |
607 | kdebug("free series"); | |
dd8632a1 | 608 | free_page_series(region->vm_start, region->vm_top); |
8feae131 DH |
609 | } |
610 | kmem_cache_free(vm_region_jar, region); | |
611 | } else { | |
612 | up_write(&nommu_region_sem); | |
1da177e4 | 613 | } |
8feae131 | 614 | } |
1da177e4 | 615 | |
8feae131 DH |
616 | /* |
617 | * release a reference to a region | |
618 | */ | |
619 | static void put_nommu_region(struct vm_region *region) | |
620 | { | |
621 | down_write(&nommu_region_sem); | |
622 | __put_nommu_region(region); | |
1da177e4 LT |
623 | } |
624 | ||
3034097a | 625 | /* |
8feae131 DH |
626 | * add a VMA into a process's mm_struct in the appropriate place in the list |
627 | * and tree and add to the address space's page tree also if not an anonymous | |
628 | * page | |
629 | * - should be called with mm->mmap_sem held writelocked | |
3034097a | 630 | */ |
8feae131 | 631 | static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma) |
1da177e4 | 632 | { |
8feae131 | 633 | struct vm_area_struct *pvma, **pp; |
1da177e4 | 634 | struct address_space *mapping; |
8feae131 DH |
635 | struct rb_node **p, *parent; |
636 | ||
637 | kenter(",%p", vma); | |
638 | ||
639 | BUG_ON(!vma->vm_region); | |
640 | ||
641 | mm->map_count++; | |
642 | vma->vm_mm = mm; | |
1da177e4 LT |
643 | |
644 | /* add the VMA to the mapping */ | |
645 | if (vma->vm_file) { | |
646 | mapping = vma->vm_file->f_mapping; | |
647 | ||
648 | flush_dcache_mmap_lock(mapping); | |
649 | vma_prio_tree_insert(vma, &mapping->i_mmap); | |
650 | flush_dcache_mmap_unlock(mapping); | |
651 | } | |
652 | ||
8feae131 DH |
653 | /* add the VMA to the tree */ |
654 | parent = NULL; | |
655 | p = &mm->mm_rb.rb_node; | |
1da177e4 LT |
656 | while (*p) { |
657 | parent = *p; | |
658 | pvma = rb_entry(parent, struct vm_area_struct, vm_rb); | |
659 | ||
8feae131 DH |
660 | /* sort by: start addr, end addr, VMA struct addr in that order |
661 | * (the latter is necessary as we may get identical VMAs) */ | |
662 | if (vma->vm_start < pvma->vm_start) | |
1da177e4 | 663 | p = &(*p)->rb_left; |
8feae131 | 664 | else if (vma->vm_start > pvma->vm_start) |
1da177e4 | 665 | p = &(*p)->rb_right; |
8feae131 DH |
666 | else if (vma->vm_end < pvma->vm_end) |
667 | p = &(*p)->rb_left; | |
668 | else if (vma->vm_end > pvma->vm_end) | |
669 | p = &(*p)->rb_right; | |
670 | else if (vma < pvma) | |
671 | p = &(*p)->rb_left; | |
672 | else if (vma > pvma) | |
673 | p = &(*p)->rb_right; | |
674 | else | |
675 | BUG(); | |
1da177e4 LT |
676 | } |
677 | ||
678 | rb_link_node(&vma->vm_rb, parent, p); | |
8feae131 DH |
679 | rb_insert_color(&vma->vm_rb, &mm->mm_rb); |
680 | ||
681 | /* add VMA to the VMA list also */ | |
682 | for (pp = &mm->mmap; (pvma = *pp); pp = &(*pp)->vm_next) { | |
683 | if (pvma->vm_start > vma->vm_start) | |
684 | break; | |
685 | if (pvma->vm_start < vma->vm_start) | |
686 | continue; | |
687 | if (pvma->vm_end < vma->vm_end) | |
688 | break; | |
689 | } | |
690 | ||
691 | vma->vm_next = *pp; | |
692 | *pp = vma; | |
1da177e4 LT |
693 | } |
694 | ||
3034097a | 695 | /* |
8feae131 | 696 | * delete a VMA from its owning mm_struct and address space |
3034097a | 697 | */ |
8feae131 | 698 | static void delete_vma_from_mm(struct vm_area_struct *vma) |
1da177e4 | 699 | { |
8feae131 | 700 | struct vm_area_struct **pp; |
1da177e4 | 701 | struct address_space *mapping; |
8feae131 DH |
702 | struct mm_struct *mm = vma->vm_mm; |
703 | ||
704 | kenter("%p", vma); | |
705 | ||
706 | mm->map_count--; | |
707 | if (mm->mmap_cache == vma) | |
708 | mm->mmap_cache = NULL; | |
1da177e4 LT |
709 | |
710 | /* remove the VMA from the mapping */ | |
711 | if (vma->vm_file) { | |
712 | mapping = vma->vm_file->f_mapping; | |
713 | ||
714 | flush_dcache_mmap_lock(mapping); | |
715 | vma_prio_tree_remove(vma, &mapping->i_mmap); | |
716 | flush_dcache_mmap_unlock(mapping); | |
717 | } | |
718 | ||
8feae131 DH |
719 | /* remove from the MM's tree and list */ |
720 | rb_erase(&vma->vm_rb, &mm->mm_rb); | |
721 | for (pp = &mm->mmap; *pp; pp = &(*pp)->vm_next) { | |
722 | if (*pp == vma) { | |
723 | *pp = vma->vm_next; | |
724 | break; | |
725 | } | |
726 | } | |
727 | ||
728 | vma->vm_mm = NULL; | |
729 | } | |
730 | ||
731 | /* | |
732 | * destroy a VMA record | |
733 | */ | |
734 | static void delete_vma(struct mm_struct *mm, struct vm_area_struct *vma) | |
735 | { | |
736 | kenter("%p", vma); | |
737 | if (vma->vm_ops && vma->vm_ops->close) | |
738 | vma->vm_ops->close(vma); | |
739 | if (vma->vm_file) { | |
740 | fput(vma->vm_file); | |
741 | if (vma->vm_flags & VM_EXECUTABLE) | |
742 | removed_exe_file_vma(mm); | |
743 | } | |
744 | put_nommu_region(vma->vm_region); | |
745 | kmem_cache_free(vm_area_cachep, vma); | |
746 | } | |
747 | ||
748 | /* | |
749 | * look up the first VMA in which addr resides, NULL if none | |
750 | * - should be called with mm->mmap_sem at least held readlocked | |
751 | */ | |
752 | struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) | |
753 | { | |
754 | struct vm_area_struct *vma; | |
755 | struct rb_node *n = mm->mm_rb.rb_node; | |
756 | ||
757 | /* check the cache first */ | |
758 | vma = mm->mmap_cache; | |
759 | if (vma && vma->vm_start <= addr && vma->vm_end > addr) | |
760 | return vma; | |
761 | ||
762 | /* trawl the tree (there may be multiple mappings in which addr | |
763 | * resides) */ | |
764 | for (n = rb_first(&mm->mm_rb); n; n = rb_next(n)) { | |
765 | vma = rb_entry(n, struct vm_area_struct, vm_rb); | |
766 | if (vma->vm_start > addr) | |
767 | return NULL; | |
768 | if (vma->vm_end > addr) { | |
769 | mm->mmap_cache = vma; | |
770 | return vma; | |
771 | } | |
772 | } | |
773 | ||
774 | return NULL; | |
775 | } | |
776 | EXPORT_SYMBOL(find_vma); | |
777 | ||
778 | /* | |
779 | * find a VMA | |
780 | * - we don't extend stack VMAs under NOMMU conditions | |
781 | */ | |
782 | struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr) | |
783 | { | |
784 | return find_vma(mm, addr); | |
785 | } | |
786 | ||
787 | /* | |
788 | * expand a stack to a given address | |
789 | * - not supported under NOMMU conditions | |
790 | */ | |
791 | int expand_stack(struct vm_area_struct *vma, unsigned long address) | |
792 | { | |
793 | return -ENOMEM; | |
794 | } | |
795 | ||
796 | /* | |
797 | * look up the first VMA exactly that exactly matches addr | |
798 | * - should be called with mm->mmap_sem at least held readlocked | |
799 | */ | |
800 | static struct vm_area_struct *find_vma_exact(struct mm_struct *mm, | |
801 | unsigned long addr, | |
802 | unsigned long len) | |
803 | { | |
804 | struct vm_area_struct *vma; | |
805 | struct rb_node *n = mm->mm_rb.rb_node; | |
806 | unsigned long end = addr + len; | |
807 | ||
808 | /* check the cache first */ | |
809 | vma = mm->mmap_cache; | |
810 | if (vma && vma->vm_start == addr && vma->vm_end == end) | |
811 | return vma; | |
812 | ||
813 | /* trawl the tree (there may be multiple mappings in which addr | |
814 | * resides) */ | |
815 | for (n = rb_first(&mm->mm_rb); n; n = rb_next(n)) { | |
816 | vma = rb_entry(n, struct vm_area_struct, vm_rb); | |
817 | if (vma->vm_start < addr) | |
818 | continue; | |
819 | if (vma->vm_start > addr) | |
820 | return NULL; | |
821 | if (vma->vm_end == end) { | |
822 | mm->mmap_cache = vma; | |
823 | return vma; | |
824 | } | |
825 | } | |
826 | ||
827 | return NULL; | |
1da177e4 LT |
828 | } |
829 | ||
830 | /* | |
831 | * determine whether a mapping should be permitted and, if so, what sort of | |
832 | * mapping we're capable of supporting | |
833 | */ | |
834 | static int validate_mmap_request(struct file *file, | |
835 | unsigned long addr, | |
836 | unsigned long len, | |
837 | unsigned long prot, | |
838 | unsigned long flags, | |
839 | unsigned long pgoff, | |
840 | unsigned long *_capabilities) | |
841 | { | |
8feae131 | 842 | unsigned long capabilities, rlen; |
1da177e4 LT |
843 | unsigned long reqprot = prot; |
844 | int ret; | |
845 | ||
846 | /* do the simple checks first */ | |
847 | if (flags & MAP_FIXED || addr) { | |
848 | printk(KERN_DEBUG | |
849 | "%d: Can't do fixed-address/overlay mmap of RAM\n", | |
850 | current->pid); | |
851 | return -EINVAL; | |
852 | } | |
853 | ||
854 | if ((flags & MAP_TYPE) != MAP_PRIVATE && | |
855 | (flags & MAP_TYPE) != MAP_SHARED) | |
856 | return -EINVAL; | |
857 | ||
f81cff0d | 858 | if (!len) |
1da177e4 LT |
859 | return -EINVAL; |
860 | ||
f81cff0d | 861 | /* Careful about overflows.. */ |
8feae131 DH |
862 | rlen = PAGE_ALIGN(len); |
863 | if (!rlen || rlen > TASK_SIZE) | |
f81cff0d MF |
864 | return -ENOMEM; |
865 | ||
1da177e4 | 866 | /* offset overflow? */ |
8feae131 | 867 | if ((pgoff + (rlen >> PAGE_SHIFT)) < pgoff) |
f81cff0d | 868 | return -EOVERFLOW; |
1da177e4 LT |
869 | |
870 | if (file) { | |
871 | /* validate file mapping requests */ | |
872 | struct address_space *mapping; | |
873 | ||
874 | /* files must support mmap */ | |
875 | if (!file->f_op || !file->f_op->mmap) | |
876 | return -ENODEV; | |
877 | ||
878 | /* work out if what we've got could possibly be shared | |
879 | * - we support chardevs that provide their own "memory" | |
880 | * - we support files/blockdevs that are memory backed | |
881 | */ | |
882 | mapping = file->f_mapping; | |
883 | if (!mapping) | |
e9536ae7 | 884 | mapping = file->f_path.dentry->d_inode->i_mapping; |
1da177e4 LT |
885 | |
886 | capabilities = 0; | |
887 | if (mapping && mapping->backing_dev_info) | |
888 | capabilities = mapping->backing_dev_info->capabilities; | |
889 | ||
890 | if (!capabilities) { | |
891 | /* no explicit capabilities set, so assume some | |
892 | * defaults */ | |
e9536ae7 | 893 | switch (file->f_path.dentry->d_inode->i_mode & S_IFMT) { |
1da177e4 LT |
894 | case S_IFREG: |
895 | case S_IFBLK: | |
896 | capabilities = BDI_CAP_MAP_COPY; | |
897 | break; | |
898 | ||
899 | case S_IFCHR: | |
900 | capabilities = | |
901 | BDI_CAP_MAP_DIRECT | | |
902 | BDI_CAP_READ_MAP | | |
903 | BDI_CAP_WRITE_MAP; | |
904 | break; | |
905 | ||
906 | default: | |
907 | return -EINVAL; | |
908 | } | |
909 | } | |
910 | ||
911 | /* eliminate any capabilities that we can't support on this | |
912 | * device */ | |
913 | if (!file->f_op->get_unmapped_area) | |
914 | capabilities &= ~BDI_CAP_MAP_DIRECT; | |
915 | if (!file->f_op->read) | |
916 | capabilities &= ~BDI_CAP_MAP_COPY; | |
917 | ||
28d7a6ae GY |
918 | /* The file shall have been opened with read permission. */ |
919 | if (!(file->f_mode & FMODE_READ)) | |
920 | return -EACCES; | |
921 | ||
1da177e4 LT |
922 | if (flags & MAP_SHARED) { |
923 | /* do checks for writing, appending and locking */ | |
924 | if ((prot & PROT_WRITE) && | |
925 | !(file->f_mode & FMODE_WRITE)) | |
926 | return -EACCES; | |
927 | ||
e9536ae7 | 928 | if (IS_APPEND(file->f_path.dentry->d_inode) && |
1da177e4 LT |
929 | (file->f_mode & FMODE_WRITE)) |
930 | return -EACCES; | |
931 | ||
e9536ae7 | 932 | if (locks_verify_locked(file->f_path.dentry->d_inode)) |
1da177e4 LT |
933 | return -EAGAIN; |
934 | ||
935 | if (!(capabilities & BDI_CAP_MAP_DIRECT)) | |
936 | return -ENODEV; | |
937 | ||
938 | if (((prot & PROT_READ) && !(capabilities & BDI_CAP_READ_MAP)) || | |
939 | ((prot & PROT_WRITE) && !(capabilities & BDI_CAP_WRITE_MAP)) || | |
940 | ((prot & PROT_EXEC) && !(capabilities & BDI_CAP_EXEC_MAP)) | |
941 | ) { | |
942 | printk("MAP_SHARED not completely supported on !MMU\n"); | |
943 | return -EINVAL; | |
944 | } | |
945 | ||
946 | /* we mustn't privatise shared mappings */ | |
947 | capabilities &= ~BDI_CAP_MAP_COPY; | |
948 | } | |
949 | else { | |
950 | /* we're going to read the file into private memory we | |
951 | * allocate */ | |
952 | if (!(capabilities & BDI_CAP_MAP_COPY)) | |
953 | return -ENODEV; | |
954 | ||
955 | /* we don't permit a private writable mapping to be | |
956 | * shared with the backing device */ | |
957 | if (prot & PROT_WRITE) | |
958 | capabilities &= ~BDI_CAP_MAP_DIRECT; | |
959 | } | |
960 | ||
961 | /* handle executable mappings and implied executable | |
962 | * mappings */ | |
e9536ae7 | 963 | if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) { |
1da177e4 LT |
964 | if (prot & PROT_EXEC) |
965 | return -EPERM; | |
966 | } | |
967 | else if ((prot & PROT_READ) && !(prot & PROT_EXEC)) { | |
968 | /* handle implication of PROT_EXEC by PROT_READ */ | |
969 | if (current->personality & READ_IMPLIES_EXEC) { | |
970 | if (capabilities & BDI_CAP_EXEC_MAP) | |
971 | prot |= PROT_EXEC; | |
972 | } | |
973 | } | |
974 | else if ((prot & PROT_READ) && | |
975 | (prot & PROT_EXEC) && | |
976 | !(capabilities & BDI_CAP_EXEC_MAP) | |
977 | ) { | |
978 | /* backing file is not executable, try to copy */ | |
979 | capabilities &= ~BDI_CAP_MAP_DIRECT; | |
980 | } | |
981 | } | |
982 | else { | |
983 | /* anonymous mappings are always memory backed and can be | |
984 | * privately mapped | |
985 | */ | |
986 | capabilities = BDI_CAP_MAP_COPY; | |
987 | ||
988 | /* handle PROT_EXEC implication by PROT_READ */ | |
989 | if ((prot & PROT_READ) && | |
990 | (current->personality & READ_IMPLIES_EXEC)) | |
991 | prot |= PROT_EXEC; | |
992 | } | |
993 | ||
994 | /* allow the security API to have its say */ | |
ed032189 | 995 | ret = security_file_mmap(file, reqprot, prot, flags, addr, 0); |
1da177e4 LT |
996 | if (ret < 0) |
997 | return ret; | |
998 | ||
999 | /* looks okay */ | |
1000 | *_capabilities = capabilities; | |
1001 | return 0; | |
1002 | } | |
1003 | ||
1004 | /* | |
1005 | * we've determined that we can make the mapping, now translate what we | |
1006 | * now know into VMA flags | |
1007 | */ | |
1008 | static unsigned long determine_vm_flags(struct file *file, | |
1009 | unsigned long prot, | |
1010 | unsigned long flags, | |
1011 | unsigned long capabilities) | |
1012 | { | |
1013 | unsigned long vm_flags; | |
1014 | ||
1015 | vm_flags = calc_vm_prot_bits(prot) | calc_vm_flag_bits(flags); | |
1016 | vm_flags |= VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC; | |
1017 | /* vm_flags |= mm->def_flags; */ | |
1018 | ||
1019 | if (!(capabilities & BDI_CAP_MAP_DIRECT)) { | |
1020 | /* attempt to share read-only copies of mapped file chunks */ | |
1021 | if (file && !(prot & PROT_WRITE)) | |
1022 | vm_flags |= VM_MAYSHARE; | |
1023 | } | |
1024 | else { | |
1025 | /* overlay a shareable mapping on the backing device or inode | |
1026 | * if possible - used for chardevs, ramfs/tmpfs/shmfs and | |
1027 | * romfs/cramfs */ | |
1028 | if (flags & MAP_SHARED) | |
1029 | vm_flags |= VM_MAYSHARE | VM_SHARED; | |
1030 | else if ((((vm_flags & capabilities) ^ vm_flags) & BDI_CAP_VMFLAGS) == 0) | |
1031 | vm_flags |= VM_MAYSHARE; | |
1032 | } | |
1033 | ||
1034 | /* refuse to let anyone share private mappings with this process if | |
1035 | * it's being traced - otherwise breakpoints set in it may interfere | |
1036 | * with another untraced process | |
1037 | */ | |
fa8e26cc | 1038 | if ((flags & MAP_PRIVATE) && tracehook_expect_breakpoints(current)) |
1da177e4 LT |
1039 | vm_flags &= ~VM_MAYSHARE; |
1040 | ||
1041 | return vm_flags; | |
1042 | } | |
1043 | ||
1044 | /* | |
8feae131 DH |
1045 | * set up a shared mapping on a file (the driver or filesystem provides and |
1046 | * pins the storage) | |
1da177e4 | 1047 | */ |
8feae131 | 1048 | static int do_mmap_shared_file(struct vm_area_struct *vma) |
1da177e4 LT |
1049 | { |
1050 | int ret; | |
1051 | ||
1052 | ret = vma->vm_file->f_op->mmap(vma->vm_file, vma); | |
dd8632a1 PM |
1053 | if (ret == 0) { |
1054 | vma->vm_region->vm_top = vma->vm_region->vm_end; | |
1055 | return ret; | |
1056 | } | |
1da177e4 LT |
1057 | if (ret != -ENOSYS) |
1058 | return ret; | |
1059 | ||
1060 | /* getting an ENOSYS error indicates that direct mmap isn't | |
1061 | * possible (as opposed to tried but failed) so we'll fall | |
1062 | * through to making a private copy of the data and mapping | |
1063 | * that if we can */ | |
1064 | return -ENODEV; | |
1065 | } | |
1066 | ||
1067 | /* | |
1068 | * set up a private mapping or an anonymous shared mapping | |
1069 | */ | |
8feae131 DH |
1070 | static int do_mmap_private(struct vm_area_struct *vma, |
1071 | struct vm_region *region, | |
1072 | unsigned long len) | |
1da177e4 | 1073 | { |
8feae131 DH |
1074 | struct page *pages; |
1075 | unsigned long total, point, n, rlen; | |
1da177e4 | 1076 | void *base; |
8feae131 | 1077 | int ret, order; |
1da177e4 LT |
1078 | |
1079 | /* invoke the file's mapping function so that it can keep track of | |
1080 | * shared mappings on devices or memory | |
1081 | * - VM_MAYSHARE will be set if it may attempt to share | |
1082 | */ | |
1083 | if (vma->vm_file) { | |
1084 | ret = vma->vm_file->f_op->mmap(vma->vm_file, vma); | |
dd8632a1 | 1085 | if (ret == 0) { |
1da177e4 | 1086 | /* shouldn't return success if we're not sharing */ |
dd8632a1 PM |
1087 | BUG_ON(!(vma->vm_flags & VM_MAYSHARE)); |
1088 | vma->vm_region->vm_top = vma->vm_region->vm_end; | |
1089 | return ret; | |
1da177e4 | 1090 | } |
dd8632a1 PM |
1091 | if (ret != -ENOSYS) |
1092 | return ret; | |
1da177e4 LT |
1093 | |
1094 | /* getting an ENOSYS error indicates that direct mmap isn't | |
1095 | * possible (as opposed to tried but failed) so we'll try to | |
1096 | * make a private copy of the data and map that instead */ | |
1097 | } | |
1098 | ||
8feae131 DH |
1099 | rlen = PAGE_ALIGN(len); |
1100 | ||
1da177e4 LT |
1101 | /* allocate some memory to hold the mapping |
1102 | * - note that this may not return a page-aligned address if the object | |
1103 | * we're allocating is smaller than a page | |
1104 | */ | |
8feae131 DH |
1105 | order = get_order(rlen); |
1106 | kdebug("alloc order %d for %lx", order, len); | |
1107 | ||
1108 | pages = alloc_pages(GFP_KERNEL, order); | |
1109 | if (!pages) | |
1da177e4 LT |
1110 | goto enomem; |
1111 | ||
8feae131 | 1112 | total = 1 << order; |
33e5d769 | 1113 | atomic_long_add(total, &mmap_pages_allocated); |
8feae131 DH |
1114 | |
1115 | point = rlen >> PAGE_SHIFT; | |
dd8632a1 PM |
1116 | |
1117 | /* we allocated a power-of-2 sized page set, so we may want to trim off | |
1118 | * the excess */ | |
1119 | if (sysctl_nr_trim_pages && total - point >= sysctl_nr_trim_pages) { | |
1120 | while (total > point) { | |
1121 | order = ilog2(total - point); | |
1122 | n = 1 << order; | |
1123 | kdebug("shave %lu/%lu @%lu", n, total - point, total); | |
33e5d769 | 1124 | atomic_long_sub(n, &mmap_pages_allocated); |
dd8632a1 PM |
1125 | total -= n; |
1126 | set_page_refcounted(pages + total); | |
1127 | __free_pages(pages + total, order); | |
1128 | } | |
8feae131 DH |
1129 | } |
1130 | ||
8feae131 DH |
1131 | for (point = 1; point < total; point++) |
1132 | set_page_refcounted(&pages[point]); | |
1da177e4 | 1133 | |
8feae131 DH |
1134 | base = page_address(pages); |
1135 | region->vm_flags = vma->vm_flags |= VM_MAPPED_COPY; | |
1136 | region->vm_start = (unsigned long) base; | |
1137 | region->vm_end = region->vm_start + rlen; | |
dd8632a1 | 1138 | region->vm_top = region->vm_start + (total << PAGE_SHIFT); |
8feae131 DH |
1139 | |
1140 | vma->vm_start = region->vm_start; | |
1141 | vma->vm_end = region->vm_start + len; | |
1da177e4 LT |
1142 | |
1143 | if (vma->vm_file) { | |
1144 | /* read the contents of a file into the copy */ | |
1145 | mm_segment_t old_fs; | |
1146 | loff_t fpos; | |
1147 | ||
1148 | fpos = vma->vm_pgoff; | |
1149 | fpos <<= PAGE_SHIFT; | |
1150 | ||
1151 | old_fs = get_fs(); | |
1152 | set_fs(KERNEL_DS); | |
8feae131 | 1153 | ret = vma->vm_file->f_op->read(vma->vm_file, base, rlen, &fpos); |
1da177e4 LT |
1154 | set_fs(old_fs); |
1155 | ||
1156 | if (ret < 0) | |
1157 | goto error_free; | |
1158 | ||
1159 | /* clear the last little bit */ | |
8feae131 DH |
1160 | if (ret < rlen) |
1161 | memset(base + ret, 0, rlen - ret); | |
1da177e4 LT |
1162 | |
1163 | } else { | |
1164 | /* if it's an anonymous mapping, then just clear it */ | |
8feae131 | 1165 | memset(base, 0, rlen); |
1da177e4 LT |
1166 | } |
1167 | ||
1168 | return 0; | |
1169 | ||
1170 | error_free: | |
8feae131 DH |
1171 | free_page_series(region->vm_start, region->vm_end); |
1172 | region->vm_start = vma->vm_start = 0; | |
1173 | region->vm_end = vma->vm_end = 0; | |
dd8632a1 | 1174 | region->vm_top = 0; |
1da177e4 LT |
1175 | return ret; |
1176 | ||
1177 | enomem: | |
05ae6fa3 GU |
1178 | printk("Allocation of length %lu from process %d (%s) failed\n", |
1179 | len, current->pid, current->comm); | |
1da177e4 LT |
1180 | show_free_areas(); |
1181 | return -ENOMEM; | |
1182 | } | |
1183 | ||
1184 | /* | |
1185 | * handle mapping creation for uClinux | |
1186 | */ | |
1187 | unsigned long do_mmap_pgoff(struct file *file, | |
1188 | unsigned long addr, | |
1189 | unsigned long len, | |
1190 | unsigned long prot, | |
1191 | unsigned long flags, | |
1192 | unsigned long pgoff) | |
1193 | { | |
8feae131 DH |
1194 | struct vm_area_struct *vma; |
1195 | struct vm_region *region; | |
1da177e4 | 1196 | struct rb_node *rb; |
8feae131 | 1197 | unsigned long capabilities, vm_flags, result; |
1da177e4 LT |
1198 | int ret; |
1199 | ||
8feae131 DH |
1200 | kenter(",%lx,%lx,%lx,%lx,%lx", addr, len, prot, flags, pgoff); |
1201 | ||
7cd94146 EP |
1202 | if (!(flags & MAP_FIXED)) |
1203 | addr = round_hint_to_min(addr); | |
1204 | ||
1da177e4 LT |
1205 | /* decide whether we should attempt the mapping, and if so what sort of |
1206 | * mapping */ | |
1207 | ret = validate_mmap_request(file, addr, len, prot, flags, pgoff, | |
1208 | &capabilities); | |
8feae131 DH |
1209 | if (ret < 0) { |
1210 | kleave(" = %d [val]", ret); | |
1da177e4 | 1211 | return ret; |
8feae131 | 1212 | } |
1da177e4 LT |
1213 | |
1214 | /* we've determined that we can make the mapping, now translate what we | |
1215 | * now know into VMA flags */ | |
1216 | vm_flags = determine_vm_flags(file, prot, flags, capabilities); | |
1217 | ||
8feae131 DH |
1218 | /* we're going to need to record the mapping */ |
1219 | region = kmem_cache_zalloc(vm_region_jar, GFP_KERNEL); | |
1220 | if (!region) | |
1221 | goto error_getting_region; | |
1222 | ||
1223 | vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL); | |
1224 | if (!vma) | |
1225 | goto error_getting_vma; | |
1da177e4 | 1226 | |
8feae131 DH |
1227 | atomic_set(®ion->vm_usage, 1); |
1228 | region->vm_flags = vm_flags; | |
1229 | region->vm_pgoff = pgoff; | |
1230 | ||
1231 | INIT_LIST_HEAD(&vma->anon_vma_node); | |
1232 | vma->vm_flags = vm_flags; | |
1233 | vma->vm_pgoff = pgoff; | |
1da177e4 | 1234 | |
8feae131 DH |
1235 | if (file) { |
1236 | region->vm_file = file; | |
1237 | get_file(file); | |
1238 | vma->vm_file = file; | |
1239 | get_file(file); | |
1240 | if (vm_flags & VM_EXECUTABLE) { | |
1241 | added_exe_file_vma(current->mm); | |
1242 | vma->vm_mm = current->mm; | |
1243 | } | |
1244 | } | |
1245 | ||
1246 | down_write(&nommu_region_sem); | |
1247 | ||
1248 | /* if we want to share, we need to check for regions created by other | |
1da177e4 | 1249 | * mmap() calls that overlap with our proposed mapping |
8feae131 | 1250 | * - we can only share with a superset match on most regular files |
1da177e4 LT |
1251 | * - shared mappings on character devices and memory backed files are |
1252 | * permitted to overlap inexactly as far as we are concerned for in | |
1253 | * these cases, sharing is handled in the driver or filesystem rather | |
1254 | * than here | |
1255 | */ | |
1256 | if (vm_flags & VM_MAYSHARE) { | |
8feae131 DH |
1257 | struct vm_region *pregion; |
1258 | unsigned long pglen, rpglen, pgend, rpgend, start; | |
1da177e4 | 1259 | |
8feae131 DH |
1260 | pglen = (len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
1261 | pgend = pgoff + pglen; | |
165b2392 | 1262 | |
8feae131 DH |
1263 | for (rb = rb_first(&nommu_region_tree); rb; rb = rb_next(rb)) { |
1264 | pregion = rb_entry(rb, struct vm_region, vm_rb); | |
1da177e4 | 1265 | |
8feae131 | 1266 | if (!(pregion->vm_flags & VM_MAYSHARE)) |
1da177e4 LT |
1267 | continue; |
1268 | ||
1269 | /* search for overlapping mappings on the same file */ | |
8feae131 DH |
1270 | if (pregion->vm_file->f_path.dentry->d_inode != |
1271 | file->f_path.dentry->d_inode) | |
1da177e4 LT |
1272 | continue; |
1273 | ||
8feae131 | 1274 | if (pregion->vm_pgoff >= pgend) |
1da177e4 LT |
1275 | continue; |
1276 | ||
8feae131 DH |
1277 | rpglen = pregion->vm_end - pregion->vm_start; |
1278 | rpglen = (rpglen + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
1279 | rpgend = pregion->vm_pgoff + rpglen; | |
1280 | if (pgoff >= rpgend) | |
1da177e4 LT |
1281 | continue; |
1282 | ||
8feae131 DH |
1283 | /* handle inexactly overlapping matches between |
1284 | * mappings */ | |
1285 | if ((pregion->vm_pgoff != pgoff || rpglen != pglen) && | |
1286 | !(pgoff >= pregion->vm_pgoff && pgend <= rpgend)) { | |
1287 | /* new mapping is not a subset of the region */ | |
1da177e4 LT |
1288 | if (!(capabilities & BDI_CAP_MAP_DIRECT)) |
1289 | goto sharing_violation; | |
1290 | continue; | |
1291 | } | |
1292 | ||
8feae131 DH |
1293 | /* we've found a region we can share */ |
1294 | atomic_inc(&pregion->vm_usage); | |
1295 | vma->vm_region = pregion; | |
1296 | start = pregion->vm_start; | |
1297 | start += (pgoff - pregion->vm_pgoff) << PAGE_SHIFT; | |
1298 | vma->vm_start = start; | |
1299 | vma->vm_end = start + len; | |
1300 | ||
1301 | if (pregion->vm_flags & VM_MAPPED_COPY) { | |
1302 | kdebug("share copy"); | |
1303 | vma->vm_flags |= VM_MAPPED_COPY; | |
1304 | } else { | |
1305 | kdebug("share mmap"); | |
1306 | ret = do_mmap_shared_file(vma); | |
1307 | if (ret < 0) { | |
1308 | vma->vm_region = NULL; | |
1309 | vma->vm_start = 0; | |
1310 | vma->vm_end = 0; | |
1311 | atomic_dec(&pregion->vm_usage); | |
1312 | pregion = NULL; | |
1313 | goto error_just_free; | |
1314 | } | |
1315 | } | |
1316 | fput(region->vm_file); | |
1317 | kmem_cache_free(vm_region_jar, region); | |
1318 | region = pregion; | |
1319 | result = start; | |
1320 | goto share; | |
1da177e4 LT |
1321 | } |
1322 | ||
1da177e4 LT |
1323 | /* obtain the address at which to make a shared mapping |
1324 | * - this is the hook for quasi-memory character devices to | |
1325 | * tell us the location of a shared mapping | |
1326 | */ | |
1327 | if (file && file->f_op->get_unmapped_area) { | |
1328 | addr = file->f_op->get_unmapped_area(file, addr, len, | |
1329 | pgoff, flags); | |
1330 | if (IS_ERR((void *) addr)) { | |
1331 | ret = addr; | |
1332 | if (ret != (unsigned long) -ENOSYS) | |
8feae131 | 1333 | goto error_just_free; |
1da177e4 LT |
1334 | |
1335 | /* the driver refused to tell us where to site | |
1336 | * the mapping so we'll have to attempt to copy | |
1337 | * it */ | |
1338 | ret = (unsigned long) -ENODEV; | |
1339 | if (!(capabilities & BDI_CAP_MAP_COPY)) | |
8feae131 | 1340 | goto error_just_free; |
1da177e4 LT |
1341 | |
1342 | capabilities &= ~BDI_CAP_MAP_DIRECT; | |
8feae131 DH |
1343 | } else { |
1344 | vma->vm_start = region->vm_start = addr; | |
1345 | vma->vm_end = region->vm_end = addr + len; | |
1da177e4 LT |
1346 | } |
1347 | } | |
1348 | } | |
1349 | ||
8feae131 | 1350 | vma->vm_region = region; |
a190887b | 1351 | add_nommu_region(region); |
1da177e4 LT |
1352 | |
1353 | /* set up the mapping */ | |
1354 | if (file && vma->vm_flags & VM_SHARED) | |
8feae131 | 1355 | ret = do_mmap_shared_file(vma); |
1da177e4 | 1356 | else |
8feae131 | 1357 | ret = do_mmap_private(vma, region, len); |
1da177e4 | 1358 | if (ret < 0) |
8feae131 DH |
1359 | goto error_put_region; |
1360 | ||
1da177e4 | 1361 | /* okay... we have a mapping; now we have to register it */ |
8feae131 | 1362 | result = vma->vm_start; |
1da177e4 | 1363 | |
1da177e4 LT |
1364 | current->mm->total_vm += len >> PAGE_SHIFT; |
1365 | ||
8feae131 DH |
1366 | share: |
1367 | add_vma_to_mm(current->mm, vma); | |
1da177e4 | 1368 | |
8feae131 | 1369 | up_write(&nommu_region_sem); |
1da177e4 LT |
1370 | |
1371 | if (prot & PROT_EXEC) | |
8feae131 | 1372 | flush_icache_range(result, result + len); |
1da177e4 | 1373 | |
8feae131 DH |
1374 | kleave(" = %lx", result); |
1375 | return result; | |
1da177e4 | 1376 | |
8feae131 DH |
1377 | error_put_region: |
1378 | __put_nommu_region(region); | |
1da177e4 | 1379 | if (vma) { |
925d1c40 | 1380 | if (vma->vm_file) { |
3fcd03e0 | 1381 | fput(vma->vm_file); |
925d1c40 MH |
1382 | if (vma->vm_flags & VM_EXECUTABLE) |
1383 | removed_exe_file_vma(vma->vm_mm); | |
1384 | } | |
8feae131 | 1385 | kmem_cache_free(vm_area_cachep, vma); |
1da177e4 | 1386 | } |
8feae131 | 1387 | kleave(" = %d [pr]", ret); |
1da177e4 LT |
1388 | return ret; |
1389 | ||
8feae131 DH |
1390 | error_just_free: |
1391 | up_write(&nommu_region_sem); | |
1392 | error: | |
1393 | fput(region->vm_file); | |
1394 | kmem_cache_free(vm_region_jar, region); | |
1395 | fput(vma->vm_file); | |
1396 | if (vma->vm_flags & VM_EXECUTABLE) | |
1397 | removed_exe_file_vma(vma->vm_mm); | |
1398 | kmem_cache_free(vm_area_cachep, vma); | |
1399 | kleave(" = %d", ret); | |
1400 | return ret; | |
1401 | ||
1402 | sharing_violation: | |
1403 | up_write(&nommu_region_sem); | |
1404 | printk(KERN_WARNING "Attempt to share mismatched mappings\n"); | |
1405 | ret = -EINVAL; | |
1406 | goto error; | |
1da177e4 | 1407 | |
8feae131 DH |
1408 | error_getting_vma: |
1409 | kmem_cache_free(vm_region_jar, region); | |
1410 | printk(KERN_WARNING "Allocation of vma for %lu byte allocation" | |
1411 | " from process %d failed\n", | |
1da177e4 LT |
1412 | len, current->pid); |
1413 | show_free_areas(); | |
1414 | return -ENOMEM; | |
1415 | ||
8feae131 DH |
1416 | error_getting_region: |
1417 | printk(KERN_WARNING "Allocation of vm region for %lu byte allocation" | |
1418 | " from process %d failed\n", | |
1da177e4 LT |
1419 | len, current->pid); |
1420 | show_free_areas(); | |
1421 | return -ENOMEM; | |
1422 | } | |
b5073173 | 1423 | EXPORT_SYMBOL(do_mmap_pgoff); |
1da177e4 LT |
1424 | |
1425 | /* | |
8feae131 DH |
1426 | * split a vma into two pieces at address 'addr', a new vma is allocated either |
1427 | * for the first part or the tail. | |
1da177e4 | 1428 | */ |
8feae131 DH |
1429 | int split_vma(struct mm_struct *mm, struct vm_area_struct *vma, |
1430 | unsigned long addr, int new_below) | |
1da177e4 | 1431 | { |
8feae131 DH |
1432 | struct vm_area_struct *new; |
1433 | struct vm_region *region; | |
1434 | unsigned long npages; | |
1da177e4 | 1435 | |
8feae131 | 1436 | kenter(""); |
1da177e4 | 1437 | |
8feae131 DH |
1438 | /* we're only permitted to split anonymous regions that have a single |
1439 | * owner */ | |
1440 | if (vma->vm_file || | |
1441 | atomic_read(&vma->vm_region->vm_usage) != 1) | |
1442 | return -ENOMEM; | |
1da177e4 | 1443 | |
8feae131 DH |
1444 | if (mm->map_count >= sysctl_max_map_count) |
1445 | return -ENOMEM; | |
1da177e4 | 1446 | |
8feae131 DH |
1447 | region = kmem_cache_alloc(vm_region_jar, GFP_KERNEL); |
1448 | if (!region) | |
1449 | return -ENOMEM; | |
1da177e4 | 1450 | |
8feae131 DH |
1451 | new = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL); |
1452 | if (!new) { | |
1453 | kmem_cache_free(vm_region_jar, region); | |
1454 | return -ENOMEM; | |
1455 | } | |
1456 | ||
1457 | /* most fields are the same, copy all, and then fixup */ | |
1458 | *new = *vma; | |
1459 | *region = *vma->vm_region; | |
1460 | new->vm_region = region; | |
1461 | ||
1462 | npages = (addr - vma->vm_start) >> PAGE_SHIFT; | |
1463 | ||
1464 | if (new_below) { | |
dd8632a1 | 1465 | region->vm_top = region->vm_end = new->vm_end = addr; |
8feae131 DH |
1466 | } else { |
1467 | region->vm_start = new->vm_start = addr; | |
1468 | region->vm_pgoff = new->vm_pgoff += npages; | |
1da177e4 | 1469 | } |
8feae131 DH |
1470 | |
1471 | if (new->vm_ops && new->vm_ops->open) | |
1472 | new->vm_ops->open(new); | |
1473 | ||
1474 | delete_vma_from_mm(vma); | |
1475 | down_write(&nommu_region_sem); | |
1476 | delete_nommu_region(vma->vm_region); | |
1477 | if (new_below) { | |
1478 | vma->vm_region->vm_start = vma->vm_start = addr; | |
1479 | vma->vm_region->vm_pgoff = vma->vm_pgoff += npages; | |
1480 | } else { | |
1481 | vma->vm_region->vm_end = vma->vm_end = addr; | |
dd8632a1 | 1482 | vma->vm_region->vm_top = addr; |
8feae131 DH |
1483 | } |
1484 | add_nommu_region(vma->vm_region); | |
1485 | add_nommu_region(new->vm_region); | |
1486 | up_write(&nommu_region_sem); | |
1487 | add_vma_to_mm(mm, vma); | |
1488 | add_vma_to_mm(mm, new); | |
1489 | return 0; | |
1da177e4 LT |
1490 | } |
1491 | ||
3034097a | 1492 | /* |
8feae131 DH |
1493 | * shrink a VMA by removing the specified chunk from either the beginning or |
1494 | * the end | |
3034097a | 1495 | */ |
8feae131 DH |
1496 | static int shrink_vma(struct mm_struct *mm, |
1497 | struct vm_area_struct *vma, | |
1498 | unsigned long from, unsigned long to) | |
1da177e4 | 1499 | { |
8feae131 | 1500 | struct vm_region *region; |
1da177e4 | 1501 | |
8feae131 | 1502 | kenter(""); |
1da177e4 | 1503 | |
8feae131 DH |
1504 | /* adjust the VMA's pointers, which may reposition it in the MM's tree |
1505 | * and list */ | |
1506 | delete_vma_from_mm(vma); | |
1507 | if (from > vma->vm_start) | |
1508 | vma->vm_end = from; | |
1509 | else | |
1510 | vma->vm_start = to; | |
1511 | add_vma_to_mm(mm, vma); | |
1da177e4 | 1512 | |
8feae131 DH |
1513 | /* cut the backing region down to size */ |
1514 | region = vma->vm_region; | |
1515 | BUG_ON(atomic_read(®ion->vm_usage) != 1); | |
1516 | ||
1517 | down_write(&nommu_region_sem); | |
1518 | delete_nommu_region(region); | |
dd8632a1 PM |
1519 | if (from > region->vm_start) { |
1520 | to = region->vm_top; | |
1521 | region->vm_top = region->vm_end = from; | |
1522 | } else { | |
8feae131 | 1523 | region->vm_start = to; |
dd8632a1 | 1524 | } |
8feae131 DH |
1525 | add_nommu_region(region); |
1526 | up_write(&nommu_region_sem); | |
1527 | ||
1528 | free_page_series(from, to); | |
1529 | return 0; | |
1530 | } | |
1da177e4 | 1531 | |
8feae131 DH |
1532 | /* |
1533 | * release a mapping | |
1534 | * - under NOMMU conditions the chunk to be unmapped must be backed by a single | |
1535 | * VMA, though it need not cover the whole VMA | |
1536 | */ | |
1537 | int do_munmap(struct mm_struct *mm, unsigned long start, size_t len) | |
1538 | { | |
1539 | struct vm_area_struct *vma; | |
1540 | struct rb_node *rb; | |
1541 | unsigned long end = start + len; | |
1542 | int ret; | |
1da177e4 | 1543 | |
8feae131 | 1544 | kenter(",%lx,%zx", start, len); |
1da177e4 | 1545 | |
8feae131 DH |
1546 | if (len == 0) |
1547 | return -EINVAL; | |
365e9c87 | 1548 | |
8feae131 DH |
1549 | /* find the first potentially overlapping VMA */ |
1550 | vma = find_vma(mm, start); | |
1551 | if (!vma) { | |
33e5d769 DH |
1552 | static int limit = 0; |
1553 | if (limit < 5) { | |
1554 | printk(KERN_WARNING | |
1555 | "munmap of memory not mmapped by process %d" | |
1556 | " (%s): 0x%lx-0x%lx\n", | |
1557 | current->pid, current->comm, | |
1558 | start, start + len - 1); | |
1559 | limit++; | |
1560 | } | |
8feae131 DH |
1561 | return -EINVAL; |
1562 | } | |
1da177e4 | 1563 | |
8feae131 DH |
1564 | /* we're allowed to split an anonymous VMA but not a file-backed one */ |
1565 | if (vma->vm_file) { | |
1566 | do { | |
1567 | if (start > vma->vm_start) { | |
1568 | kleave(" = -EINVAL [miss]"); | |
1569 | return -EINVAL; | |
1570 | } | |
1571 | if (end == vma->vm_end) | |
1572 | goto erase_whole_vma; | |
1573 | rb = rb_next(&vma->vm_rb); | |
1574 | vma = rb_entry(rb, struct vm_area_struct, vm_rb); | |
1575 | } while (rb); | |
1576 | kleave(" = -EINVAL [split file]"); | |
1577 | return -EINVAL; | |
1578 | } else { | |
1579 | /* the chunk must be a subset of the VMA found */ | |
1580 | if (start == vma->vm_start && end == vma->vm_end) | |
1581 | goto erase_whole_vma; | |
1582 | if (start < vma->vm_start || end > vma->vm_end) { | |
1583 | kleave(" = -EINVAL [superset]"); | |
1584 | return -EINVAL; | |
1585 | } | |
1586 | if (start & ~PAGE_MASK) { | |
1587 | kleave(" = -EINVAL [unaligned start]"); | |
1588 | return -EINVAL; | |
1589 | } | |
1590 | if (end != vma->vm_end && end & ~PAGE_MASK) { | |
1591 | kleave(" = -EINVAL [unaligned split]"); | |
1592 | return -EINVAL; | |
1593 | } | |
1594 | if (start != vma->vm_start && end != vma->vm_end) { | |
1595 | ret = split_vma(mm, vma, start, 1); | |
1596 | if (ret < 0) { | |
1597 | kleave(" = %d [split]", ret); | |
1598 | return ret; | |
1599 | } | |
1600 | } | |
1601 | return shrink_vma(mm, vma, start, end); | |
1602 | } | |
1da177e4 | 1603 | |
8feae131 DH |
1604 | erase_whole_vma: |
1605 | delete_vma_from_mm(vma); | |
1606 | delete_vma(mm, vma); | |
1607 | kleave(" = 0"); | |
1da177e4 LT |
1608 | return 0; |
1609 | } | |
b5073173 | 1610 | EXPORT_SYMBOL(do_munmap); |
1da177e4 | 1611 | |
6a6160a7 | 1612 | SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len) |
3034097a DH |
1613 | { |
1614 | int ret; | |
1615 | struct mm_struct *mm = current->mm; | |
1616 | ||
1617 | down_write(&mm->mmap_sem); | |
1618 | ret = do_munmap(mm, addr, len); | |
1619 | up_write(&mm->mmap_sem); | |
1620 | return ret; | |
1621 | } | |
1622 | ||
1623 | /* | |
8feae131 | 1624 | * release all the mappings made in a process's VM space |
3034097a | 1625 | */ |
8feae131 | 1626 | void exit_mmap(struct mm_struct *mm) |
1da177e4 | 1627 | { |
8feae131 | 1628 | struct vm_area_struct *vma; |
1da177e4 | 1629 | |
8feae131 DH |
1630 | if (!mm) |
1631 | return; | |
1da177e4 | 1632 | |
8feae131 | 1633 | kenter(""); |
1da177e4 | 1634 | |
8feae131 | 1635 | mm->total_vm = 0; |
1da177e4 | 1636 | |
8feae131 DH |
1637 | while ((vma = mm->mmap)) { |
1638 | mm->mmap = vma->vm_next; | |
1639 | delete_vma_from_mm(vma); | |
1640 | delete_vma(mm, vma); | |
1da177e4 | 1641 | } |
8feae131 DH |
1642 | |
1643 | kleave(""); | |
1da177e4 LT |
1644 | } |
1645 | ||
1da177e4 LT |
1646 | unsigned long do_brk(unsigned long addr, unsigned long len) |
1647 | { | |
1648 | return -ENOMEM; | |
1649 | } | |
1650 | ||
1651 | /* | |
6fa5f80b DH |
1652 | * expand (or shrink) an existing mapping, potentially moving it at the same |
1653 | * time (controlled by the MREMAP_MAYMOVE flag and available VM space) | |
1da177e4 | 1654 | * |
6fa5f80b | 1655 | * under NOMMU conditions, we only permit changing a mapping's size, and only |
8feae131 DH |
1656 | * as long as it stays within the region allocated by do_mmap_private() and the |
1657 | * block is not shareable | |
1da177e4 | 1658 | * |
6fa5f80b | 1659 | * MREMAP_FIXED is not supported under NOMMU conditions |
1da177e4 LT |
1660 | */ |
1661 | unsigned long do_mremap(unsigned long addr, | |
1662 | unsigned long old_len, unsigned long new_len, | |
1663 | unsigned long flags, unsigned long new_addr) | |
1664 | { | |
6fa5f80b | 1665 | struct vm_area_struct *vma; |
1da177e4 LT |
1666 | |
1667 | /* insanity checks first */ | |
8feae131 | 1668 | if (old_len == 0 || new_len == 0) |
1da177e4 LT |
1669 | return (unsigned long) -EINVAL; |
1670 | ||
8feae131 DH |
1671 | if (addr & ~PAGE_MASK) |
1672 | return -EINVAL; | |
1673 | ||
1da177e4 LT |
1674 | if (flags & MREMAP_FIXED && new_addr != addr) |
1675 | return (unsigned long) -EINVAL; | |
1676 | ||
8feae131 | 1677 | vma = find_vma_exact(current->mm, addr, old_len); |
6fa5f80b DH |
1678 | if (!vma) |
1679 | return (unsigned long) -EINVAL; | |
1da177e4 | 1680 | |
6fa5f80b | 1681 | if (vma->vm_end != vma->vm_start + old_len) |
1da177e4 LT |
1682 | return (unsigned long) -EFAULT; |
1683 | ||
6fa5f80b | 1684 | if (vma->vm_flags & VM_MAYSHARE) |
1da177e4 LT |
1685 | return (unsigned long) -EPERM; |
1686 | ||
8feae131 | 1687 | if (new_len > vma->vm_region->vm_end - vma->vm_region->vm_start) |
1da177e4 LT |
1688 | return (unsigned long) -ENOMEM; |
1689 | ||
1690 | /* all checks complete - do it */ | |
6fa5f80b | 1691 | vma->vm_end = vma->vm_start + new_len; |
6fa5f80b DH |
1692 | return vma->vm_start; |
1693 | } | |
b5073173 | 1694 | EXPORT_SYMBOL(do_mremap); |
6fa5f80b | 1695 | |
6a6160a7 HC |
1696 | SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, |
1697 | unsigned long, new_len, unsigned long, flags, | |
1698 | unsigned long, new_addr) | |
6fa5f80b DH |
1699 | { |
1700 | unsigned long ret; | |
1701 | ||
1702 | down_write(¤t->mm->mmap_sem); | |
1703 | ret = do_mremap(addr, old_len, new_len, flags, new_addr); | |
1704 | up_write(¤t->mm->mmap_sem); | |
1705 | return ret; | |
1da177e4 LT |
1706 | } |
1707 | ||
6aab341e | 1708 | struct page *follow_page(struct vm_area_struct *vma, unsigned long address, |
deceb6cd | 1709 | unsigned int foll_flags) |
1da177e4 LT |
1710 | { |
1711 | return NULL; | |
1712 | } | |
1713 | ||
1da177e4 LT |
1714 | int remap_pfn_range(struct vm_area_struct *vma, unsigned long from, |
1715 | unsigned long to, unsigned long size, pgprot_t prot) | |
1716 | { | |
66aa2b4b GU |
1717 | vma->vm_start = vma->vm_pgoff << PAGE_SHIFT; |
1718 | return 0; | |
1da177e4 | 1719 | } |
22c4af40 | 1720 | EXPORT_SYMBOL(remap_pfn_range); |
1da177e4 | 1721 | |
f905bc44 PM |
1722 | int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, |
1723 | unsigned long pgoff) | |
1724 | { | |
1725 | unsigned int size = vma->vm_end - vma->vm_start; | |
1726 | ||
1727 | if (!(vma->vm_flags & VM_USERMAP)) | |
1728 | return -EINVAL; | |
1729 | ||
1730 | vma->vm_start = (unsigned long)(addr + (pgoff << PAGE_SHIFT)); | |
1731 | vma->vm_end = vma->vm_start + size; | |
1732 | ||
1733 | return 0; | |
1734 | } | |
1735 | EXPORT_SYMBOL(remap_vmalloc_range); | |
1736 | ||
1da177e4 LT |
1737 | void swap_unplug_io_fn(struct backing_dev_info *bdi, struct page *page) |
1738 | { | |
1739 | } | |
1740 | ||
1741 | unsigned long arch_get_unmapped_area(struct file *file, unsigned long addr, | |
1742 | unsigned long len, unsigned long pgoff, unsigned long flags) | |
1743 | { | |
1744 | return -ENOMEM; | |
1745 | } | |
1746 | ||
1363c3cd | 1747 | void arch_unmap_area(struct mm_struct *mm, unsigned long addr) |
1da177e4 LT |
1748 | { |
1749 | } | |
1750 | ||
1da177e4 LT |
1751 | void unmap_mapping_range(struct address_space *mapping, |
1752 | loff_t const holebegin, loff_t const holelen, | |
1753 | int even_cows) | |
1754 | { | |
1755 | } | |
22c4af40 | 1756 | EXPORT_SYMBOL(unmap_mapping_range); |
1da177e4 | 1757 | |
d56e03cd DH |
1758 | /* |
1759 | * ask for an unmapped area at which to create a mapping on a file | |
1760 | */ | |
1761 | unsigned long get_unmapped_area(struct file *file, unsigned long addr, | |
1762 | unsigned long len, unsigned long pgoff, | |
1763 | unsigned long flags) | |
1764 | { | |
1765 | unsigned long (*get_area)(struct file *, unsigned long, unsigned long, | |
1766 | unsigned long, unsigned long); | |
1767 | ||
1768 | get_area = current->mm->get_unmapped_area; | |
1769 | if (file && file->f_op && file->f_op->get_unmapped_area) | |
1770 | get_area = file->f_op->get_unmapped_area; | |
1771 | ||
1772 | if (!get_area) | |
1773 | return -ENOSYS; | |
1774 | ||
1775 | return get_area(file, addr, len, pgoff, flags); | |
1776 | } | |
d56e03cd DH |
1777 | EXPORT_SYMBOL(get_unmapped_area); |
1778 | ||
1da177e4 LT |
1779 | /* |
1780 | * Check that a process has enough memory to allocate a new virtual | |
1781 | * mapping. 0 means there is enough memory for the allocation to | |
1782 | * succeed and -ENOMEM implies there is not. | |
1783 | * | |
1784 | * We currently support three overcommit policies, which are set via the | |
1785 | * vm.overcommit_memory sysctl. See Documentation/vm/overcommit-accounting | |
1786 | * | |
1787 | * Strict overcommit modes added 2002 Feb 26 by Alan Cox. | |
1788 | * Additional code 2002 Jul 20 by Robert Love. | |
1789 | * | |
1790 | * cap_sys_admin is 1 if the process has admin privileges, 0 otherwise. | |
1791 | * | |
1792 | * Note this is a helper function intended to be used by LSMs which | |
1793 | * wish to use this logic. | |
1794 | */ | |
34b4e4aa | 1795 | int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin) |
1da177e4 LT |
1796 | { |
1797 | unsigned long free, allowed; | |
1798 | ||
1799 | vm_acct_memory(pages); | |
1800 | ||
1801 | /* | |
1802 | * Sometimes we want to use more memory than we have | |
1803 | */ | |
1804 | if (sysctl_overcommit_memory == OVERCOMMIT_ALWAYS) | |
1805 | return 0; | |
1806 | ||
1807 | if (sysctl_overcommit_memory == OVERCOMMIT_GUESS) { | |
1808 | unsigned long n; | |
1809 | ||
347ce434 | 1810 | free = global_page_state(NR_FILE_PAGES); |
1da177e4 LT |
1811 | free += nr_swap_pages; |
1812 | ||
1813 | /* | |
1814 | * Any slabs which are created with the | |
1815 | * SLAB_RECLAIM_ACCOUNT flag claim to have contents | |
1816 | * which are reclaimable, under pressure. The dentry | |
1817 | * cache and most inode caches should fall into this | |
1818 | */ | |
972d1a7b | 1819 | free += global_page_state(NR_SLAB_RECLAIMABLE); |
1da177e4 LT |
1820 | |
1821 | /* | |
1822 | * Leave the last 3% for root | |
1823 | */ | |
1824 | if (!cap_sys_admin) | |
1825 | free -= free / 32; | |
1826 | ||
1827 | if (free > pages) | |
1828 | return 0; | |
1829 | ||
1830 | /* | |
1831 | * nr_free_pages() is very expensive on large systems, | |
1832 | * only call if we're about to fail. | |
1833 | */ | |
1834 | n = nr_free_pages(); | |
d5ddc79b HA |
1835 | |
1836 | /* | |
1837 | * Leave reserved pages. The pages are not for anonymous pages. | |
1838 | */ | |
1839 | if (n <= totalreserve_pages) | |
1840 | goto error; | |
1841 | else | |
1842 | n -= totalreserve_pages; | |
1843 | ||
1844 | /* | |
1845 | * Leave the last 3% for root | |
1846 | */ | |
1da177e4 LT |
1847 | if (!cap_sys_admin) |
1848 | n -= n / 32; | |
1849 | free += n; | |
1850 | ||
1851 | if (free > pages) | |
1852 | return 0; | |
d5ddc79b HA |
1853 | |
1854 | goto error; | |
1da177e4 LT |
1855 | } |
1856 | ||
1857 | allowed = totalram_pages * sysctl_overcommit_ratio / 100; | |
1858 | /* | |
1859 | * Leave the last 3% for root | |
1860 | */ | |
1861 | if (!cap_sys_admin) | |
1862 | allowed -= allowed / 32; | |
1863 | allowed += total_swap_pages; | |
1864 | ||
1865 | /* Don't let a single process grow too big: | |
1866 | leave 3% of the size of this process for other processes */ | |
731572d3 AC |
1867 | if (mm) |
1868 | allowed -= mm->total_vm / 32; | |
1da177e4 | 1869 | |
00a62ce9 | 1870 | if (percpu_counter_read_positive(&vm_committed_as) < allowed) |
1da177e4 | 1871 | return 0; |
00a62ce9 | 1872 | |
d5ddc79b | 1873 | error: |
1da177e4 LT |
1874 | vm_unacct_memory(pages); |
1875 | ||
1876 | return -ENOMEM; | |
1877 | } | |
1878 | ||
1879 | int in_gate_area_no_task(unsigned long addr) | |
1880 | { | |
1881 | return 0; | |
1882 | } | |
b0e15190 | 1883 | |
d0217ac0 | 1884 | int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
b0e15190 DH |
1885 | { |
1886 | BUG(); | |
d0217ac0 | 1887 | return 0; |
b0e15190 | 1888 | } |
b5073173 | 1889 | EXPORT_SYMBOL(filemap_fault); |
0ec76a11 DH |
1890 | |
1891 | /* | |
1892 | * Access another process' address space. | |
1893 | * - source/target buffer must be kernel space | |
1894 | */ | |
1895 | int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write) | |
1896 | { | |
0ec76a11 DH |
1897 | struct vm_area_struct *vma; |
1898 | struct mm_struct *mm; | |
1899 | ||
1900 | if (addr + len < addr) | |
1901 | return 0; | |
1902 | ||
1903 | mm = get_task_mm(tsk); | |
1904 | if (!mm) | |
1905 | return 0; | |
1906 | ||
1907 | down_read(&mm->mmap_sem); | |
1908 | ||
1909 | /* the access must start within one of the target process's mappings */ | |
0159b141 DH |
1910 | vma = find_vma(mm, addr); |
1911 | if (vma) { | |
0ec76a11 DH |
1912 | /* don't overrun this mapping */ |
1913 | if (addr + len >= vma->vm_end) | |
1914 | len = vma->vm_end - addr; | |
1915 | ||
1916 | /* only read or write mappings where it is permitted */ | |
d00c7b99 | 1917 | if (write && vma->vm_flags & VM_MAYWRITE) |
0ec76a11 | 1918 | len -= copy_to_user((void *) addr, buf, len); |
d00c7b99 | 1919 | else if (!write && vma->vm_flags & VM_MAYREAD) |
0ec76a11 DH |
1920 | len -= copy_from_user(buf, (void *) addr, len); |
1921 | else | |
1922 | len = 0; | |
1923 | } else { | |
1924 | len = 0; | |
1925 | } | |
1926 | ||
1927 | up_read(&mm->mmap_sem); | |
1928 | mmput(mm); | |
1929 | return len; | |
1930 | } |