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> | |
dd8632a1 | 13 | * Copyright (c) 2007-2008 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; | |
80119ef5 | 65 | atomic_long_t vm_committed_space = ATOMIC_LONG_INIT(0); |
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; | |
dd8632a1 | 69 | int sysctl_nr_trim_pages = 1; /* page trimming behaviour */ |
1da177e4 LT |
70 | int heap_stack_gap = 0; |
71 | ||
8feae131 DH |
72 | atomic_t mmap_pages_allocated; |
73 | ||
1da177e4 | 74 | EXPORT_SYMBOL(mem_map); |
6a04de6d | 75 | EXPORT_SYMBOL(num_physpages); |
1da177e4 | 76 | |
8feae131 DH |
77 | /* list of mapped, potentially shareable regions */ |
78 | static struct kmem_cache *vm_region_jar; | |
79 | struct rb_root nommu_region_tree = RB_ROOT; | |
80 | DECLARE_RWSEM(nommu_region_sem); | |
1da177e4 LT |
81 | |
82 | struct vm_operations_struct generic_file_vm_ops = { | |
83 | }; | |
84 | ||
85 | /* | |
86 | * Handle all mappings that got truncated by a "truncate()" | |
87 | * system call. | |
88 | * | |
89 | * NOTE! We have to be ready to update the memory sharing | |
90 | * between the file and the memory map for a potential last | |
91 | * incomplete page. Ugly, but necessary. | |
92 | */ | |
93 | int vmtruncate(struct inode *inode, loff_t offset) | |
94 | { | |
95 | struct address_space *mapping = inode->i_mapping; | |
96 | unsigned long limit; | |
97 | ||
98 | if (inode->i_size < offset) | |
99 | goto do_expand; | |
100 | i_size_write(inode, offset); | |
101 | ||
102 | truncate_inode_pages(mapping, offset); | |
103 | goto out_truncate; | |
104 | ||
105 | do_expand: | |
106 | limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur; | |
107 | if (limit != RLIM_INFINITY && offset > limit) | |
108 | goto out_sig; | |
109 | if (offset > inode->i_sb->s_maxbytes) | |
110 | goto out; | |
111 | i_size_write(inode, offset); | |
112 | ||
113 | out_truncate: | |
acfa4380 | 114 | if (inode->i_op->truncate) |
1da177e4 LT |
115 | inode->i_op->truncate(inode); |
116 | return 0; | |
117 | out_sig: | |
118 | send_sig(SIGXFSZ, current, 0); | |
119 | out: | |
120 | return -EFBIG; | |
121 | } | |
122 | ||
123 | EXPORT_SYMBOL(vmtruncate); | |
124 | ||
125 | /* | |
126 | * Return the total memory allocated for this pointer, not | |
127 | * just what the caller asked for. | |
128 | * | |
129 | * Doesn't have to be accurate, i.e. may have races. | |
130 | */ | |
131 | unsigned int kobjsize(const void *objp) | |
132 | { | |
133 | struct page *page; | |
134 | ||
4016a139 MH |
135 | /* |
136 | * If the object we have should not have ksize performed on it, | |
137 | * return size of 0 | |
138 | */ | |
5a1603be | 139 | if (!objp || !virt_addr_valid(objp)) |
6cfd53fc PM |
140 | return 0; |
141 | ||
142 | page = virt_to_head_page(objp); | |
6cfd53fc PM |
143 | |
144 | /* | |
145 | * If the allocator sets PageSlab, we know the pointer came from | |
146 | * kmalloc(). | |
147 | */ | |
1da177e4 LT |
148 | if (PageSlab(page)) |
149 | return ksize(objp); | |
150 | ||
6cfd53fc PM |
151 | /* |
152 | * The ksize() function is only guaranteed to work for pointers | |
5a1603be | 153 | * returned by kmalloc(). So handle arbitrary pointers here. |
6cfd53fc | 154 | */ |
5a1603be | 155 | return PAGE_SIZE << compound_order(page); |
1da177e4 LT |
156 | } |
157 | ||
b291f000 NP |
158 | int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, |
159 | unsigned long start, int len, int flags, | |
160 | struct page **pages, struct vm_area_struct **vmas) | |
1da177e4 | 161 | { |
910e46da | 162 | struct vm_area_struct *vma; |
7b4d5b8b DH |
163 | unsigned long vm_flags; |
164 | int i; | |
b291f000 NP |
165 | int write = !!(flags & GUP_FLAGS_WRITE); |
166 | int force = !!(flags & GUP_FLAGS_FORCE); | |
167 | int ignore = !!(flags & GUP_FLAGS_IGNORE_VMA_PERMISSIONS); | |
7b4d5b8b DH |
168 | |
169 | /* calculate required read or write permissions. | |
170 | * - if 'force' is set, we only require the "MAY" flags. | |
171 | */ | |
172 | vm_flags = write ? (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD); | |
173 | vm_flags &= force ? (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE); | |
1da177e4 LT |
174 | |
175 | for (i = 0; i < len; i++) { | |
910e46da | 176 | vma = find_vma(mm, start); |
7b4d5b8b DH |
177 | if (!vma) |
178 | goto finish_or_fault; | |
179 | ||
180 | /* protect what we can, including chardevs */ | |
181 | if (vma->vm_flags & (VM_IO | VM_PFNMAP) || | |
b291f000 | 182 | (!ignore && !(vm_flags & vma->vm_flags))) |
7b4d5b8b | 183 | goto finish_or_fault; |
910e46da | 184 | |
1da177e4 LT |
185 | if (pages) { |
186 | pages[i] = virt_to_page(start); | |
187 | if (pages[i]) | |
188 | page_cache_get(pages[i]); | |
189 | } | |
190 | if (vmas) | |
910e46da | 191 | vmas[i] = vma; |
1da177e4 LT |
192 | start += PAGE_SIZE; |
193 | } | |
7b4d5b8b DH |
194 | |
195 | return i; | |
196 | ||
197 | finish_or_fault: | |
198 | return i ? : -EFAULT; | |
1da177e4 | 199 | } |
b291f000 NP |
200 | |
201 | ||
202 | /* | |
203 | * get a list of pages in an address range belonging to the specified process | |
204 | * and indicate the VMA that covers each page | |
205 | * - this is potentially dodgy as we may end incrementing the page count of a | |
206 | * slab page or a secondary page from a compound page | |
207 | * - don't permit access to VMAs that don't support it, such as I/O mappings | |
208 | */ | |
209 | int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, | |
210 | unsigned long start, int len, int write, int force, | |
211 | struct page **pages, struct vm_area_struct **vmas) | |
212 | { | |
213 | int flags = 0; | |
214 | ||
215 | if (write) | |
216 | flags |= GUP_FLAGS_WRITE; | |
217 | if (force) | |
218 | flags |= GUP_FLAGS_FORCE; | |
219 | ||
220 | return __get_user_pages(tsk, mm, | |
221 | start, len, flags, | |
222 | pages, vmas); | |
223 | } | |
66aa2b4b GU |
224 | EXPORT_SYMBOL(get_user_pages); |
225 | ||
1da177e4 LT |
226 | DEFINE_RWLOCK(vmlist_lock); |
227 | struct vm_struct *vmlist; | |
228 | ||
b3bdda02 | 229 | void vfree(const void *addr) |
1da177e4 LT |
230 | { |
231 | kfree(addr); | |
232 | } | |
b5073173 | 233 | EXPORT_SYMBOL(vfree); |
1da177e4 | 234 | |
dd0fc66f | 235 | void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot) |
1da177e4 LT |
236 | { |
237 | /* | |
8518609d RD |
238 | * You can't specify __GFP_HIGHMEM with kmalloc() since kmalloc() |
239 | * returns only a logical address. | |
1da177e4 | 240 | */ |
84097518 | 241 | return kmalloc(size, (gfp_mask | __GFP_COMP) & ~__GFP_HIGHMEM); |
1da177e4 | 242 | } |
b5073173 | 243 | EXPORT_SYMBOL(__vmalloc); |
1da177e4 | 244 | |
f905bc44 PM |
245 | void *vmalloc_user(unsigned long size) |
246 | { | |
247 | void *ret; | |
248 | ||
249 | ret = __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO, | |
250 | PAGE_KERNEL); | |
251 | if (ret) { | |
252 | struct vm_area_struct *vma; | |
253 | ||
254 | down_write(¤t->mm->mmap_sem); | |
255 | vma = find_vma(current->mm, (unsigned long)ret); | |
256 | if (vma) | |
257 | vma->vm_flags |= VM_USERMAP; | |
258 | up_write(¤t->mm->mmap_sem); | |
259 | } | |
260 | ||
261 | return ret; | |
262 | } | |
263 | EXPORT_SYMBOL(vmalloc_user); | |
264 | ||
b3bdda02 | 265 | struct page *vmalloc_to_page(const void *addr) |
1da177e4 LT |
266 | { |
267 | return virt_to_page(addr); | |
268 | } | |
b5073173 | 269 | EXPORT_SYMBOL(vmalloc_to_page); |
1da177e4 | 270 | |
b3bdda02 | 271 | unsigned long vmalloc_to_pfn(const void *addr) |
1da177e4 LT |
272 | { |
273 | return page_to_pfn(virt_to_page(addr)); | |
274 | } | |
b5073173 | 275 | EXPORT_SYMBOL(vmalloc_to_pfn); |
1da177e4 LT |
276 | |
277 | long vread(char *buf, char *addr, unsigned long count) | |
278 | { | |
279 | memcpy(buf, addr, count); | |
280 | return count; | |
281 | } | |
282 | ||
283 | long vwrite(char *buf, char *addr, unsigned long count) | |
284 | { | |
285 | /* Don't allow overflow */ | |
286 | if ((unsigned long) addr + count < count) | |
287 | count = -(unsigned long) addr; | |
288 | ||
289 | memcpy(addr, buf, count); | |
290 | return(count); | |
291 | } | |
292 | ||
293 | /* | |
294 | * vmalloc - allocate virtually continguos memory | |
295 | * | |
296 | * @size: allocation size | |
297 | * | |
298 | * Allocate enough pages to cover @size from the page level | |
299 | * allocator and map them into continguos kernel virtual space. | |
300 | * | |
c1c8897f | 301 | * For tight control over page level allocator and protection flags |
1da177e4 LT |
302 | * use __vmalloc() instead. |
303 | */ | |
304 | void *vmalloc(unsigned long size) | |
305 | { | |
306 | return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL); | |
307 | } | |
f6138882 AM |
308 | EXPORT_SYMBOL(vmalloc); |
309 | ||
310 | void *vmalloc_node(unsigned long size, int node) | |
311 | { | |
312 | return vmalloc(size); | |
313 | } | |
314 | EXPORT_SYMBOL(vmalloc_node); | |
1da177e4 | 315 | |
1af446ed PM |
316 | #ifndef PAGE_KERNEL_EXEC |
317 | # define PAGE_KERNEL_EXEC PAGE_KERNEL | |
318 | #endif | |
319 | ||
320 | /** | |
321 | * vmalloc_exec - allocate virtually contiguous, executable memory | |
322 | * @size: allocation size | |
323 | * | |
324 | * Kernel-internal function to allocate enough pages to cover @size | |
325 | * the page level allocator and map them into contiguous and | |
326 | * executable kernel virtual space. | |
327 | * | |
328 | * For tight control over page level allocator and protection flags | |
329 | * use __vmalloc() instead. | |
330 | */ | |
331 | ||
332 | void *vmalloc_exec(unsigned long size) | |
333 | { | |
334 | return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC); | |
335 | } | |
336 | ||
b5073173 PM |
337 | /** |
338 | * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) | |
1da177e4 LT |
339 | * @size: allocation size |
340 | * | |
341 | * Allocate enough 32bit PA addressable pages to cover @size from the | |
342 | * page level allocator and map them into continguos kernel virtual space. | |
343 | */ | |
344 | void *vmalloc_32(unsigned long size) | |
345 | { | |
346 | return __vmalloc(size, GFP_KERNEL, PAGE_KERNEL); | |
347 | } | |
b5073173 PM |
348 | EXPORT_SYMBOL(vmalloc_32); |
349 | ||
350 | /** | |
351 | * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory | |
352 | * @size: allocation size | |
353 | * | |
354 | * The resulting memory area is 32bit addressable and zeroed so it can be | |
355 | * mapped to userspace without leaking data. | |
f905bc44 PM |
356 | * |
357 | * VM_USERMAP is set on the corresponding VMA so that subsequent calls to | |
358 | * remap_vmalloc_range() are permissible. | |
b5073173 PM |
359 | */ |
360 | void *vmalloc_32_user(unsigned long size) | |
361 | { | |
f905bc44 PM |
362 | /* |
363 | * We'll have to sort out the ZONE_DMA bits for 64-bit, | |
364 | * but for now this can simply use vmalloc_user() directly. | |
365 | */ | |
366 | return vmalloc_user(size); | |
b5073173 PM |
367 | } |
368 | EXPORT_SYMBOL(vmalloc_32_user); | |
1da177e4 LT |
369 | |
370 | void *vmap(struct page **pages, unsigned int count, unsigned long flags, pgprot_t prot) | |
371 | { | |
372 | BUG(); | |
373 | return NULL; | |
374 | } | |
b5073173 | 375 | EXPORT_SYMBOL(vmap); |
1da177e4 | 376 | |
b3bdda02 | 377 | void vunmap(const void *addr) |
1da177e4 LT |
378 | { |
379 | BUG(); | |
380 | } | |
b5073173 | 381 | EXPORT_SYMBOL(vunmap); |
1da177e4 | 382 | |
1eeb66a1 CH |
383 | /* |
384 | * Implement a stub for vmalloc_sync_all() if the architecture chose not to | |
385 | * have one. | |
386 | */ | |
387 | void __attribute__((weak)) vmalloc_sync_all(void) | |
388 | { | |
389 | } | |
390 | ||
b5073173 PM |
391 | int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, |
392 | struct page *page) | |
393 | { | |
394 | return -EINVAL; | |
395 | } | |
396 | EXPORT_SYMBOL(vm_insert_page); | |
397 | ||
1da177e4 LT |
398 | /* |
399 | * sys_brk() for the most part doesn't need the global kernel | |
400 | * lock, except when an application is doing something nasty | |
401 | * like trying to un-brk an area that has already been mapped | |
402 | * to a regular file. in this case, the unmapping will need | |
403 | * to invoke file system routines that need the global lock. | |
404 | */ | |
405 | asmlinkage unsigned long sys_brk(unsigned long brk) | |
406 | { | |
407 | struct mm_struct *mm = current->mm; | |
408 | ||
409 | if (brk < mm->start_brk || brk > mm->context.end_brk) | |
410 | return mm->brk; | |
411 | ||
412 | if (mm->brk == brk) | |
413 | return mm->brk; | |
414 | ||
415 | /* | |
416 | * Always allow shrinking brk | |
417 | */ | |
418 | if (brk <= mm->brk) { | |
419 | mm->brk = brk; | |
420 | return brk; | |
421 | } | |
422 | ||
423 | /* | |
424 | * Ok, looks good - let it rip. | |
425 | */ | |
426 | return mm->brk = brk; | |
427 | } | |
428 | ||
8feae131 DH |
429 | /* |
430 | * initialise the VMA and region record slabs | |
431 | */ | |
432 | void __init mmap_init(void) | |
1da177e4 | 433 | { |
8feae131 DH |
434 | vm_region_jar = kmem_cache_create("vm_region_jar", |
435 | sizeof(struct vm_region), 0, | |
436 | SLAB_PANIC, NULL); | |
437 | vm_area_cachep = kmem_cache_create("vm_area_struct", | |
438 | sizeof(struct vm_area_struct), 0, | |
439 | SLAB_PANIC, NULL); | |
1da177e4 | 440 | } |
1da177e4 | 441 | |
3034097a | 442 | /* |
8feae131 DH |
443 | * validate the region tree |
444 | * - the caller must hold the region lock | |
3034097a | 445 | */ |
8feae131 DH |
446 | #ifdef CONFIG_DEBUG_NOMMU_REGIONS |
447 | static noinline void validate_nommu_regions(void) | |
3034097a | 448 | { |
8feae131 DH |
449 | struct vm_region *region, *last; |
450 | struct rb_node *p, *lastp; | |
3034097a | 451 | |
8feae131 DH |
452 | lastp = rb_first(&nommu_region_tree); |
453 | if (!lastp) | |
454 | return; | |
455 | ||
456 | last = rb_entry(lastp, struct vm_region, vm_rb); | |
457 | if (unlikely(last->vm_end <= last->vm_start)) | |
458 | BUG(); | |
dd8632a1 PM |
459 | if (unlikely(last->vm_top < last->vm_end)) |
460 | BUG(); | |
8feae131 DH |
461 | |
462 | while ((p = rb_next(lastp))) { | |
463 | region = rb_entry(p, struct vm_region, vm_rb); | |
464 | last = rb_entry(lastp, struct vm_region, vm_rb); | |
465 | ||
466 | if (unlikely(region->vm_end <= region->vm_start)) | |
467 | BUG(); | |
dd8632a1 PM |
468 | if (unlikely(region->vm_top < region->vm_end)) |
469 | BUG(); | |
470 | if (unlikely(region->vm_start < last->vm_top)) | |
8feae131 | 471 | BUG(); |
3034097a | 472 | |
8feae131 DH |
473 | lastp = p; |
474 | } | |
3034097a | 475 | } |
8feae131 DH |
476 | #else |
477 | #define validate_nommu_regions() do {} while(0) | |
478 | #endif | |
3034097a DH |
479 | |
480 | /* | |
8feae131 | 481 | * add a region into the global tree |
3034097a | 482 | */ |
8feae131 | 483 | static void add_nommu_region(struct vm_region *region) |
3034097a | 484 | { |
8feae131 DH |
485 | struct vm_region *pregion; |
486 | struct rb_node **p, *parent; | |
3034097a | 487 | |
8feae131 DH |
488 | validate_nommu_regions(); |
489 | ||
490 | BUG_ON(region->vm_start & ~PAGE_MASK); | |
491 | ||
492 | parent = NULL; | |
493 | p = &nommu_region_tree.rb_node; | |
494 | while (*p) { | |
495 | parent = *p; | |
496 | pregion = rb_entry(parent, struct vm_region, vm_rb); | |
497 | if (region->vm_start < pregion->vm_start) | |
498 | p = &(*p)->rb_left; | |
499 | else if (region->vm_start > pregion->vm_start) | |
500 | p = &(*p)->rb_right; | |
501 | else if (pregion == region) | |
502 | return; | |
503 | else | |
504 | BUG(); | |
3034097a DH |
505 | } |
506 | ||
8feae131 DH |
507 | rb_link_node(®ion->vm_rb, parent, p); |
508 | rb_insert_color(®ion->vm_rb, &nommu_region_tree); | |
3034097a | 509 | |
8feae131 | 510 | validate_nommu_regions(); |
3034097a | 511 | } |
3034097a | 512 | |
930e652a | 513 | /* |
8feae131 | 514 | * delete a region from the global tree |
930e652a | 515 | */ |
8feae131 | 516 | static void delete_nommu_region(struct vm_region *region) |
930e652a | 517 | { |
8feae131 | 518 | BUG_ON(!nommu_region_tree.rb_node); |
930e652a | 519 | |
8feae131 DH |
520 | validate_nommu_regions(); |
521 | rb_erase(®ion->vm_rb, &nommu_region_tree); | |
522 | validate_nommu_regions(); | |
57c8f63e GU |
523 | } |
524 | ||
6fa5f80b | 525 | /* |
8feae131 | 526 | * free a contiguous series of pages |
6fa5f80b | 527 | */ |
8feae131 | 528 | static void free_page_series(unsigned long from, unsigned long to) |
6fa5f80b | 529 | { |
8feae131 DH |
530 | for (; from < to; from += PAGE_SIZE) { |
531 | struct page *page = virt_to_page(from); | |
532 | ||
533 | kdebug("- free %lx", from); | |
534 | atomic_dec(&mmap_pages_allocated); | |
535 | if (page_count(page) != 1) | |
536 | kdebug("free page %p [%d]", page, page_count(page)); | |
537 | put_page(page); | |
6fa5f80b | 538 | } |
6fa5f80b DH |
539 | } |
540 | ||
3034097a | 541 | /* |
8feae131 DH |
542 | * release a reference to a region |
543 | * - the caller must hold the region semaphore, which this releases | |
dd8632a1 | 544 | * - the region may not have been added to the tree yet, in which case vm_top |
8feae131 | 545 | * will equal vm_start |
3034097a | 546 | */ |
8feae131 DH |
547 | static void __put_nommu_region(struct vm_region *region) |
548 | __releases(nommu_region_sem) | |
1da177e4 | 549 | { |
8feae131 | 550 | kenter("%p{%d}", region, atomic_read(®ion->vm_usage)); |
1da177e4 | 551 | |
8feae131 | 552 | BUG_ON(!nommu_region_tree.rb_node); |
1da177e4 | 553 | |
8feae131 | 554 | if (atomic_dec_and_test(®ion->vm_usage)) { |
dd8632a1 | 555 | if (region->vm_top > region->vm_start) |
8feae131 DH |
556 | delete_nommu_region(region); |
557 | up_write(&nommu_region_sem); | |
558 | ||
559 | if (region->vm_file) | |
560 | fput(region->vm_file); | |
561 | ||
562 | /* IO memory and memory shared directly out of the pagecache | |
563 | * from ramfs/tmpfs mustn't be released here */ | |
564 | if (region->vm_flags & VM_MAPPED_COPY) { | |
565 | kdebug("free series"); | |
dd8632a1 | 566 | free_page_series(region->vm_start, region->vm_top); |
8feae131 DH |
567 | } |
568 | kmem_cache_free(vm_region_jar, region); | |
569 | } else { | |
570 | up_write(&nommu_region_sem); | |
1da177e4 | 571 | } |
8feae131 | 572 | } |
1da177e4 | 573 | |
8feae131 DH |
574 | /* |
575 | * release a reference to a region | |
576 | */ | |
577 | static void put_nommu_region(struct vm_region *region) | |
578 | { | |
579 | down_write(&nommu_region_sem); | |
580 | __put_nommu_region(region); | |
1da177e4 LT |
581 | } |
582 | ||
3034097a | 583 | /* |
8feae131 DH |
584 | * add a VMA into a process's mm_struct in the appropriate place in the list |
585 | * and tree and add to the address space's page tree also if not an anonymous | |
586 | * page | |
587 | * - should be called with mm->mmap_sem held writelocked | |
3034097a | 588 | */ |
8feae131 | 589 | static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma) |
1da177e4 | 590 | { |
8feae131 | 591 | struct vm_area_struct *pvma, **pp; |
1da177e4 | 592 | struct address_space *mapping; |
8feae131 DH |
593 | struct rb_node **p, *parent; |
594 | ||
595 | kenter(",%p", vma); | |
596 | ||
597 | BUG_ON(!vma->vm_region); | |
598 | ||
599 | mm->map_count++; | |
600 | vma->vm_mm = mm; | |
1da177e4 LT |
601 | |
602 | /* add the VMA to the mapping */ | |
603 | if (vma->vm_file) { | |
604 | mapping = vma->vm_file->f_mapping; | |
605 | ||
606 | flush_dcache_mmap_lock(mapping); | |
607 | vma_prio_tree_insert(vma, &mapping->i_mmap); | |
608 | flush_dcache_mmap_unlock(mapping); | |
609 | } | |
610 | ||
8feae131 DH |
611 | /* add the VMA to the tree */ |
612 | parent = NULL; | |
613 | p = &mm->mm_rb.rb_node; | |
1da177e4 LT |
614 | while (*p) { |
615 | parent = *p; | |
616 | pvma = rb_entry(parent, struct vm_area_struct, vm_rb); | |
617 | ||
8feae131 DH |
618 | /* sort by: start addr, end addr, VMA struct addr in that order |
619 | * (the latter is necessary as we may get identical VMAs) */ | |
620 | if (vma->vm_start < pvma->vm_start) | |
1da177e4 | 621 | p = &(*p)->rb_left; |
8feae131 | 622 | else if (vma->vm_start > pvma->vm_start) |
1da177e4 | 623 | p = &(*p)->rb_right; |
8feae131 DH |
624 | else if (vma->vm_end < pvma->vm_end) |
625 | p = &(*p)->rb_left; | |
626 | else if (vma->vm_end > pvma->vm_end) | |
627 | p = &(*p)->rb_right; | |
628 | else if (vma < pvma) | |
629 | p = &(*p)->rb_left; | |
630 | else if (vma > pvma) | |
631 | p = &(*p)->rb_right; | |
632 | else | |
633 | BUG(); | |
1da177e4 LT |
634 | } |
635 | ||
636 | rb_link_node(&vma->vm_rb, parent, p); | |
8feae131 DH |
637 | rb_insert_color(&vma->vm_rb, &mm->mm_rb); |
638 | ||
639 | /* add VMA to the VMA list also */ | |
640 | for (pp = &mm->mmap; (pvma = *pp); pp = &(*pp)->vm_next) { | |
641 | if (pvma->vm_start > vma->vm_start) | |
642 | break; | |
643 | if (pvma->vm_start < vma->vm_start) | |
644 | continue; | |
645 | if (pvma->vm_end < vma->vm_end) | |
646 | break; | |
647 | } | |
648 | ||
649 | vma->vm_next = *pp; | |
650 | *pp = vma; | |
1da177e4 LT |
651 | } |
652 | ||
3034097a | 653 | /* |
8feae131 | 654 | * delete a VMA from its owning mm_struct and address space |
3034097a | 655 | */ |
8feae131 | 656 | static void delete_vma_from_mm(struct vm_area_struct *vma) |
1da177e4 | 657 | { |
8feae131 | 658 | struct vm_area_struct **pp; |
1da177e4 | 659 | struct address_space *mapping; |
8feae131 DH |
660 | struct mm_struct *mm = vma->vm_mm; |
661 | ||
662 | kenter("%p", vma); | |
663 | ||
664 | mm->map_count--; | |
665 | if (mm->mmap_cache == vma) | |
666 | mm->mmap_cache = NULL; | |
1da177e4 LT |
667 | |
668 | /* remove the VMA from the mapping */ | |
669 | if (vma->vm_file) { | |
670 | mapping = vma->vm_file->f_mapping; | |
671 | ||
672 | flush_dcache_mmap_lock(mapping); | |
673 | vma_prio_tree_remove(vma, &mapping->i_mmap); | |
674 | flush_dcache_mmap_unlock(mapping); | |
675 | } | |
676 | ||
8feae131 DH |
677 | /* remove from the MM's tree and list */ |
678 | rb_erase(&vma->vm_rb, &mm->mm_rb); | |
679 | for (pp = &mm->mmap; *pp; pp = &(*pp)->vm_next) { | |
680 | if (*pp == vma) { | |
681 | *pp = vma->vm_next; | |
682 | break; | |
683 | } | |
684 | } | |
685 | ||
686 | vma->vm_mm = NULL; | |
687 | } | |
688 | ||
689 | /* | |
690 | * destroy a VMA record | |
691 | */ | |
692 | static void delete_vma(struct mm_struct *mm, struct vm_area_struct *vma) | |
693 | { | |
694 | kenter("%p", vma); | |
695 | if (vma->vm_ops && vma->vm_ops->close) | |
696 | vma->vm_ops->close(vma); | |
697 | if (vma->vm_file) { | |
698 | fput(vma->vm_file); | |
699 | if (vma->vm_flags & VM_EXECUTABLE) | |
700 | removed_exe_file_vma(mm); | |
701 | } | |
702 | put_nommu_region(vma->vm_region); | |
703 | kmem_cache_free(vm_area_cachep, vma); | |
704 | } | |
705 | ||
706 | /* | |
707 | * look up the first VMA in which addr resides, NULL if none | |
708 | * - should be called with mm->mmap_sem at least held readlocked | |
709 | */ | |
710 | struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) | |
711 | { | |
712 | struct vm_area_struct *vma; | |
713 | struct rb_node *n = mm->mm_rb.rb_node; | |
714 | ||
715 | /* check the cache first */ | |
716 | vma = mm->mmap_cache; | |
717 | if (vma && vma->vm_start <= addr && vma->vm_end > addr) | |
718 | return vma; | |
719 | ||
720 | /* trawl the tree (there may be multiple mappings in which addr | |
721 | * resides) */ | |
722 | for (n = rb_first(&mm->mm_rb); n; n = rb_next(n)) { | |
723 | vma = rb_entry(n, struct vm_area_struct, vm_rb); | |
724 | if (vma->vm_start > addr) | |
725 | return NULL; | |
726 | if (vma->vm_end > addr) { | |
727 | mm->mmap_cache = vma; | |
728 | return vma; | |
729 | } | |
730 | } | |
731 | ||
732 | return NULL; | |
733 | } | |
734 | EXPORT_SYMBOL(find_vma); | |
735 | ||
736 | /* | |
737 | * find a VMA | |
738 | * - we don't extend stack VMAs under NOMMU conditions | |
739 | */ | |
740 | struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr) | |
741 | { | |
742 | return find_vma(mm, addr); | |
743 | } | |
744 | ||
745 | /* | |
746 | * expand a stack to a given address | |
747 | * - not supported under NOMMU conditions | |
748 | */ | |
749 | int expand_stack(struct vm_area_struct *vma, unsigned long address) | |
750 | { | |
751 | return -ENOMEM; | |
752 | } | |
753 | ||
754 | /* | |
755 | * look up the first VMA exactly that exactly matches addr | |
756 | * - should be called with mm->mmap_sem at least held readlocked | |
757 | */ | |
758 | static struct vm_area_struct *find_vma_exact(struct mm_struct *mm, | |
759 | unsigned long addr, | |
760 | unsigned long len) | |
761 | { | |
762 | struct vm_area_struct *vma; | |
763 | struct rb_node *n = mm->mm_rb.rb_node; | |
764 | unsigned long end = addr + len; | |
765 | ||
766 | /* check the cache first */ | |
767 | vma = mm->mmap_cache; | |
768 | if (vma && vma->vm_start == addr && vma->vm_end == end) | |
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 | continue; | |
777 | if (vma->vm_start > addr) | |
778 | return NULL; | |
779 | if (vma->vm_end == end) { | |
780 | mm->mmap_cache = vma; | |
781 | return vma; | |
782 | } | |
783 | } | |
784 | ||
785 | return NULL; | |
1da177e4 LT |
786 | } |
787 | ||
788 | /* | |
789 | * determine whether a mapping should be permitted and, if so, what sort of | |
790 | * mapping we're capable of supporting | |
791 | */ | |
792 | static int validate_mmap_request(struct file *file, | |
793 | unsigned long addr, | |
794 | unsigned long len, | |
795 | unsigned long prot, | |
796 | unsigned long flags, | |
797 | unsigned long pgoff, | |
798 | unsigned long *_capabilities) | |
799 | { | |
8feae131 | 800 | unsigned long capabilities, rlen; |
1da177e4 LT |
801 | unsigned long reqprot = prot; |
802 | int ret; | |
803 | ||
804 | /* do the simple checks first */ | |
805 | if (flags & MAP_FIXED || addr) { | |
806 | printk(KERN_DEBUG | |
807 | "%d: Can't do fixed-address/overlay mmap of RAM\n", | |
808 | current->pid); | |
809 | return -EINVAL; | |
810 | } | |
811 | ||
812 | if ((flags & MAP_TYPE) != MAP_PRIVATE && | |
813 | (flags & MAP_TYPE) != MAP_SHARED) | |
814 | return -EINVAL; | |
815 | ||
f81cff0d | 816 | if (!len) |
1da177e4 LT |
817 | return -EINVAL; |
818 | ||
f81cff0d | 819 | /* Careful about overflows.. */ |
8feae131 DH |
820 | rlen = PAGE_ALIGN(len); |
821 | if (!rlen || rlen > TASK_SIZE) | |
f81cff0d MF |
822 | return -ENOMEM; |
823 | ||
1da177e4 | 824 | /* offset overflow? */ |
8feae131 | 825 | if ((pgoff + (rlen >> PAGE_SHIFT)) < pgoff) |
f81cff0d | 826 | return -EOVERFLOW; |
1da177e4 LT |
827 | |
828 | if (file) { | |
829 | /* validate file mapping requests */ | |
830 | struct address_space *mapping; | |
831 | ||
832 | /* files must support mmap */ | |
833 | if (!file->f_op || !file->f_op->mmap) | |
834 | return -ENODEV; | |
835 | ||
836 | /* work out if what we've got could possibly be shared | |
837 | * - we support chardevs that provide their own "memory" | |
838 | * - we support files/blockdevs that are memory backed | |
839 | */ | |
840 | mapping = file->f_mapping; | |
841 | if (!mapping) | |
e9536ae7 | 842 | mapping = file->f_path.dentry->d_inode->i_mapping; |
1da177e4 LT |
843 | |
844 | capabilities = 0; | |
845 | if (mapping && mapping->backing_dev_info) | |
846 | capabilities = mapping->backing_dev_info->capabilities; | |
847 | ||
848 | if (!capabilities) { | |
849 | /* no explicit capabilities set, so assume some | |
850 | * defaults */ | |
e9536ae7 | 851 | switch (file->f_path.dentry->d_inode->i_mode & S_IFMT) { |
1da177e4 LT |
852 | case S_IFREG: |
853 | case S_IFBLK: | |
854 | capabilities = BDI_CAP_MAP_COPY; | |
855 | break; | |
856 | ||
857 | case S_IFCHR: | |
858 | capabilities = | |
859 | BDI_CAP_MAP_DIRECT | | |
860 | BDI_CAP_READ_MAP | | |
861 | BDI_CAP_WRITE_MAP; | |
862 | break; | |
863 | ||
864 | default: | |
865 | return -EINVAL; | |
866 | } | |
867 | } | |
868 | ||
869 | /* eliminate any capabilities that we can't support on this | |
870 | * device */ | |
871 | if (!file->f_op->get_unmapped_area) | |
872 | capabilities &= ~BDI_CAP_MAP_DIRECT; | |
873 | if (!file->f_op->read) | |
874 | capabilities &= ~BDI_CAP_MAP_COPY; | |
875 | ||
876 | if (flags & MAP_SHARED) { | |
877 | /* do checks for writing, appending and locking */ | |
878 | if ((prot & PROT_WRITE) && | |
879 | !(file->f_mode & FMODE_WRITE)) | |
880 | return -EACCES; | |
881 | ||
e9536ae7 | 882 | if (IS_APPEND(file->f_path.dentry->d_inode) && |
1da177e4 LT |
883 | (file->f_mode & FMODE_WRITE)) |
884 | return -EACCES; | |
885 | ||
e9536ae7 | 886 | if (locks_verify_locked(file->f_path.dentry->d_inode)) |
1da177e4 LT |
887 | return -EAGAIN; |
888 | ||
889 | if (!(capabilities & BDI_CAP_MAP_DIRECT)) | |
890 | return -ENODEV; | |
891 | ||
892 | if (((prot & PROT_READ) && !(capabilities & BDI_CAP_READ_MAP)) || | |
893 | ((prot & PROT_WRITE) && !(capabilities & BDI_CAP_WRITE_MAP)) || | |
894 | ((prot & PROT_EXEC) && !(capabilities & BDI_CAP_EXEC_MAP)) | |
895 | ) { | |
896 | printk("MAP_SHARED not completely supported on !MMU\n"); | |
897 | return -EINVAL; | |
898 | } | |
899 | ||
900 | /* we mustn't privatise shared mappings */ | |
901 | capabilities &= ~BDI_CAP_MAP_COPY; | |
902 | } | |
903 | else { | |
904 | /* we're going to read the file into private memory we | |
905 | * allocate */ | |
906 | if (!(capabilities & BDI_CAP_MAP_COPY)) | |
907 | return -ENODEV; | |
908 | ||
909 | /* we don't permit a private writable mapping to be | |
910 | * shared with the backing device */ | |
911 | if (prot & PROT_WRITE) | |
912 | capabilities &= ~BDI_CAP_MAP_DIRECT; | |
913 | } | |
914 | ||
915 | /* handle executable mappings and implied executable | |
916 | * mappings */ | |
e9536ae7 | 917 | if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) { |
1da177e4 LT |
918 | if (prot & PROT_EXEC) |
919 | return -EPERM; | |
920 | } | |
921 | else if ((prot & PROT_READ) && !(prot & PROT_EXEC)) { | |
922 | /* handle implication of PROT_EXEC by PROT_READ */ | |
923 | if (current->personality & READ_IMPLIES_EXEC) { | |
924 | if (capabilities & BDI_CAP_EXEC_MAP) | |
925 | prot |= PROT_EXEC; | |
926 | } | |
927 | } | |
928 | else if ((prot & PROT_READ) && | |
929 | (prot & PROT_EXEC) && | |
930 | !(capabilities & BDI_CAP_EXEC_MAP) | |
931 | ) { | |
932 | /* backing file is not executable, try to copy */ | |
933 | capabilities &= ~BDI_CAP_MAP_DIRECT; | |
934 | } | |
935 | } | |
936 | else { | |
937 | /* anonymous mappings are always memory backed and can be | |
938 | * privately mapped | |
939 | */ | |
940 | capabilities = BDI_CAP_MAP_COPY; | |
941 | ||
942 | /* handle PROT_EXEC implication by PROT_READ */ | |
943 | if ((prot & PROT_READ) && | |
944 | (current->personality & READ_IMPLIES_EXEC)) | |
945 | prot |= PROT_EXEC; | |
946 | } | |
947 | ||
948 | /* allow the security API to have its say */ | |
ed032189 | 949 | ret = security_file_mmap(file, reqprot, prot, flags, addr, 0); |
1da177e4 LT |
950 | if (ret < 0) |
951 | return ret; | |
952 | ||
953 | /* looks okay */ | |
954 | *_capabilities = capabilities; | |
955 | return 0; | |
956 | } | |
957 | ||
958 | /* | |
959 | * we've determined that we can make the mapping, now translate what we | |
960 | * now know into VMA flags | |
961 | */ | |
962 | static unsigned long determine_vm_flags(struct file *file, | |
963 | unsigned long prot, | |
964 | unsigned long flags, | |
965 | unsigned long capabilities) | |
966 | { | |
967 | unsigned long vm_flags; | |
968 | ||
969 | vm_flags = calc_vm_prot_bits(prot) | calc_vm_flag_bits(flags); | |
970 | vm_flags |= VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC; | |
971 | /* vm_flags |= mm->def_flags; */ | |
972 | ||
973 | if (!(capabilities & BDI_CAP_MAP_DIRECT)) { | |
974 | /* attempt to share read-only copies of mapped file chunks */ | |
975 | if (file && !(prot & PROT_WRITE)) | |
976 | vm_flags |= VM_MAYSHARE; | |
977 | } | |
978 | else { | |
979 | /* overlay a shareable mapping on the backing device or inode | |
980 | * if possible - used for chardevs, ramfs/tmpfs/shmfs and | |
981 | * romfs/cramfs */ | |
982 | if (flags & MAP_SHARED) | |
983 | vm_flags |= VM_MAYSHARE | VM_SHARED; | |
984 | else if ((((vm_flags & capabilities) ^ vm_flags) & BDI_CAP_VMFLAGS) == 0) | |
985 | vm_flags |= VM_MAYSHARE; | |
986 | } | |
987 | ||
988 | /* refuse to let anyone share private mappings with this process if | |
989 | * it's being traced - otherwise breakpoints set in it may interfere | |
990 | * with another untraced process | |
991 | */ | |
fa8e26cc | 992 | if ((flags & MAP_PRIVATE) && tracehook_expect_breakpoints(current)) |
1da177e4 LT |
993 | vm_flags &= ~VM_MAYSHARE; |
994 | ||
995 | return vm_flags; | |
996 | } | |
997 | ||
998 | /* | |
8feae131 DH |
999 | * set up a shared mapping on a file (the driver or filesystem provides and |
1000 | * pins the storage) | |
1da177e4 | 1001 | */ |
8feae131 | 1002 | static int do_mmap_shared_file(struct vm_area_struct *vma) |
1da177e4 LT |
1003 | { |
1004 | int ret; | |
1005 | ||
1006 | ret = vma->vm_file->f_op->mmap(vma->vm_file, vma); | |
dd8632a1 PM |
1007 | if (ret == 0) { |
1008 | vma->vm_region->vm_top = vma->vm_region->vm_end; | |
1009 | return ret; | |
1010 | } | |
1da177e4 LT |
1011 | if (ret != -ENOSYS) |
1012 | return ret; | |
1013 | ||
1014 | /* getting an ENOSYS error indicates that direct mmap isn't | |
1015 | * possible (as opposed to tried but failed) so we'll fall | |
1016 | * through to making a private copy of the data and mapping | |
1017 | * that if we can */ | |
1018 | return -ENODEV; | |
1019 | } | |
1020 | ||
1021 | /* | |
1022 | * set up a private mapping or an anonymous shared mapping | |
1023 | */ | |
8feae131 DH |
1024 | static int do_mmap_private(struct vm_area_struct *vma, |
1025 | struct vm_region *region, | |
1026 | unsigned long len) | |
1da177e4 | 1027 | { |
8feae131 DH |
1028 | struct page *pages; |
1029 | unsigned long total, point, n, rlen; | |
1da177e4 | 1030 | void *base; |
8feae131 | 1031 | int ret, order; |
1da177e4 LT |
1032 | |
1033 | /* invoke the file's mapping function so that it can keep track of | |
1034 | * shared mappings on devices or memory | |
1035 | * - VM_MAYSHARE will be set if it may attempt to share | |
1036 | */ | |
1037 | if (vma->vm_file) { | |
1038 | ret = vma->vm_file->f_op->mmap(vma->vm_file, vma); | |
dd8632a1 | 1039 | if (ret == 0) { |
1da177e4 | 1040 | /* shouldn't return success if we're not sharing */ |
dd8632a1 PM |
1041 | BUG_ON(!(vma->vm_flags & VM_MAYSHARE)); |
1042 | vma->vm_region->vm_top = vma->vm_region->vm_end; | |
1043 | return ret; | |
1da177e4 | 1044 | } |
dd8632a1 PM |
1045 | if (ret != -ENOSYS) |
1046 | return ret; | |
1da177e4 LT |
1047 | |
1048 | /* getting an ENOSYS error indicates that direct mmap isn't | |
1049 | * possible (as opposed to tried but failed) so we'll try to | |
1050 | * make a private copy of the data and map that instead */ | |
1051 | } | |
1052 | ||
8feae131 DH |
1053 | rlen = PAGE_ALIGN(len); |
1054 | ||
1da177e4 LT |
1055 | /* allocate some memory to hold the mapping |
1056 | * - note that this may not return a page-aligned address if the object | |
1057 | * we're allocating is smaller than a page | |
1058 | */ | |
8feae131 DH |
1059 | order = get_order(rlen); |
1060 | kdebug("alloc order %d for %lx", order, len); | |
1061 | ||
1062 | pages = alloc_pages(GFP_KERNEL, order); | |
1063 | if (!pages) | |
1da177e4 LT |
1064 | goto enomem; |
1065 | ||
8feae131 DH |
1066 | total = 1 << order; |
1067 | atomic_add(total, &mmap_pages_allocated); | |
1068 | ||
1069 | point = rlen >> PAGE_SHIFT; | |
dd8632a1 PM |
1070 | |
1071 | /* we allocated a power-of-2 sized page set, so we may want to trim off | |
1072 | * the excess */ | |
1073 | if (sysctl_nr_trim_pages && total - point >= sysctl_nr_trim_pages) { | |
1074 | while (total > point) { | |
1075 | order = ilog2(total - point); | |
1076 | n = 1 << order; | |
1077 | kdebug("shave %lu/%lu @%lu", n, total - point, total); | |
1078 | atomic_sub(n, &mmap_pages_allocated); | |
1079 | total -= n; | |
1080 | set_page_refcounted(pages + total); | |
1081 | __free_pages(pages + total, order); | |
1082 | } | |
8feae131 DH |
1083 | } |
1084 | ||
8feae131 DH |
1085 | for (point = 1; point < total; point++) |
1086 | set_page_refcounted(&pages[point]); | |
1da177e4 | 1087 | |
8feae131 DH |
1088 | base = page_address(pages); |
1089 | region->vm_flags = vma->vm_flags |= VM_MAPPED_COPY; | |
1090 | region->vm_start = (unsigned long) base; | |
1091 | region->vm_end = region->vm_start + rlen; | |
dd8632a1 | 1092 | region->vm_top = region->vm_start + (total << PAGE_SHIFT); |
8feae131 DH |
1093 | |
1094 | vma->vm_start = region->vm_start; | |
1095 | vma->vm_end = region->vm_start + len; | |
1da177e4 LT |
1096 | |
1097 | if (vma->vm_file) { | |
1098 | /* read the contents of a file into the copy */ | |
1099 | mm_segment_t old_fs; | |
1100 | loff_t fpos; | |
1101 | ||
1102 | fpos = vma->vm_pgoff; | |
1103 | fpos <<= PAGE_SHIFT; | |
1104 | ||
1105 | old_fs = get_fs(); | |
1106 | set_fs(KERNEL_DS); | |
8feae131 | 1107 | ret = vma->vm_file->f_op->read(vma->vm_file, base, rlen, &fpos); |
1da177e4 LT |
1108 | set_fs(old_fs); |
1109 | ||
1110 | if (ret < 0) | |
1111 | goto error_free; | |
1112 | ||
1113 | /* clear the last little bit */ | |
8feae131 DH |
1114 | if (ret < rlen) |
1115 | memset(base + ret, 0, rlen - ret); | |
1da177e4 LT |
1116 | |
1117 | } else { | |
1118 | /* if it's an anonymous mapping, then just clear it */ | |
8feae131 | 1119 | memset(base, 0, rlen); |
1da177e4 LT |
1120 | } |
1121 | ||
1122 | return 0; | |
1123 | ||
1124 | error_free: | |
8feae131 DH |
1125 | free_page_series(region->vm_start, region->vm_end); |
1126 | region->vm_start = vma->vm_start = 0; | |
1127 | region->vm_end = vma->vm_end = 0; | |
dd8632a1 | 1128 | region->vm_top = 0; |
1da177e4 LT |
1129 | return ret; |
1130 | ||
1131 | enomem: | |
1132 | printk("Allocation of length %lu from process %d failed\n", | |
1133 | len, current->pid); | |
1134 | show_free_areas(); | |
1135 | return -ENOMEM; | |
1136 | } | |
1137 | ||
1138 | /* | |
1139 | * handle mapping creation for uClinux | |
1140 | */ | |
1141 | unsigned long do_mmap_pgoff(struct file *file, | |
1142 | unsigned long addr, | |
1143 | unsigned long len, | |
1144 | unsigned long prot, | |
1145 | unsigned long flags, | |
1146 | unsigned long pgoff) | |
1147 | { | |
8feae131 DH |
1148 | struct vm_area_struct *vma; |
1149 | struct vm_region *region; | |
1da177e4 | 1150 | struct rb_node *rb; |
8feae131 | 1151 | unsigned long capabilities, vm_flags, result; |
1da177e4 LT |
1152 | int ret; |
1153 | ||
8feae131 DH |
1154 | kenter(",%lx,%lx,%lx,%lx,%lx", addr, len, prot, flags, pgoff); |
1155 | ||
7cd94146 EP |
1156 | if (!(flags & MAP_FIXED)) |
1157 | addr = round_hint_to_min(addr); | |
1158 | ||
1da177e4 LT |
1159 | /* decide whether we should attempt the mapping, and if so what sort of |
1160 | * mapping */ | |
1161 | ret = validate_mmap_request(file, addr, len, prot, flags, pgoff, | |
1162 | &capabilities); | |
8feae131 DH |
1163 | if (ret < 0) { |
1164 | kleave(" = %d [val]", ret); | |
1da177e4 | 1165 | return ret; |
8feae131 | 1166 | } |
1da177e4 LT |
1167 | |
1168 | /* we've determined that we can make the mapping, now translate what we | |
1169 | * now know into VMA flags */ | |
1170 | vm_flags = determine_vm_flags(file, prot, flags, capabilities); | |
1171 | ||
8feae131 DH |
1172 | /* we're going to need to record the mapping */ |
1173 | region = kmem_cache_zalloc(vm_region_jar, GFP_KERNEL); | |
1174 | if (!region) | |
1175 | goto error_getting_region; | |
1176 | ||
1177 | vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL); | |
1178 | if (!vma) | |
1179 | goto error_getting_vma; | |
1da177e4 | 1180 | |
8feae131 DH |
1181 | atomic_set(®ion->vm_usage, 1); |
1182 | region->vm_flags = vm_flags; | |
1183 | region->vm_pgoff = pgoff; | |
1184 | ||
1185 | INIT_LIST_HEAD(&vma->anon_vma_node); | |
1186 | vma->vm_flags = vm_flags; | |
1187 | vma->vm_pgoff = pgoff; | |
1da177e4 | 1188 | |
8feae131 DH |
1189 | if (file) { |
1190 | region->vm_file = file; | |
1191 | get_file(file); | |
1192 | vma->vm_file = file; | |
1193 | get_file(file); | |
1194 | if (vm_flags & VM_EXECUTABLE) { | |
1195 | added_exe_file_vma(current->mm); | |
1196 | vma->vm_mm = current->mm; | |
1197 | } | |
1198 | } | |
1199 | ||
1200 | down_write(&nommu_region_sem); | |
1201 | ||
1202 | /* if we want to share, we need to check for regions created by other | |
1da177e4 | 1203 | * mmap() calls that overlap with our proposed mapping |
8feae131 | 1204 | * - we can only share with a superset match on most regular files |
1da177e4 LT |
1205 | * - shared mappings on character devices and memory backed files are |
1206 | * permitted to overlap inexactly as far as we are concerned for in | |
1207 | * these cases, sharing is handled in the driver or filesystem rather | |
1208 | * than here | |
1209 | */ | |
1210 | if (vm_flags & VM_MAYSHARE) { | |
8feae131 DH |
1211 | struct vm_region *pregion; |
1212 | unsigned long pglen, rpglen, pgend, rpgend, start; | |
1da177e4 | 1213 | |
8feae131 DH |
1214 | pglen = (len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
1215 | pgend = pgoff + pglen; | |
165b2392 | 1216 | |
8feae131 DH |
1217 | for (rb = rb_first(&nommu_region_tree); rb; rb = rb_next(rb)) { |
1218 | pregion = rb_entry(rb, struct vm_region, vm_rb); | |
1da177e4 | 1219 | |
8feae131 | 1220 | if (!(pregion->vm_flags & VM_MAYSHARE)) |
1da177e4 LT |
1221 | continue; |
1222 | ||
1223 | /* search for overlapping mappings on the same file */ | |
8feae131 DH |
1224 | if (pregion->vm_file->f_path.dentry->d_inode != |
1225 | file->f_path.dentry->d_inode) | |
1da177e4 LT |
1226 | continue; |
1227 | ||
8feae131 | 1228 | if (pregion->vm_pgoff >= pgend) |
1da177e4 LT |
1229 | continue; |
1230 | ||
8feae131 DH |
1231 | rpglen = pregion->vm_end - pregion->vm_start; |
1232 | rpglen = (rpglen + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
1233 | rpgend = pregion->vm_pgoff + rpglen; | |
1234 | if (pgoff >= rpgend) | |
1da177e4 LT |
1235 | continue; |
1236 | ||
8feae131 DH |
1237 | /* handle inexactly overlapping matches between |
1238 | * mappings */ | |
1239 | if ((pregion->vm_pgoff != pgoff || rpglen != pglen) && | |
1240 | !(pgoff >= pregion->vm_pgoff && pgend <= rpgend)) { | |
1241 | /* new mapping is not a subset of the region */ | |
1da177e4 LT |
1242 | if (!(capabilities & BDI_CAP_MAP_DIRECT)) |
1243 | goto sharing_violation; | |
1244 | continue; | |
1245 | } | |
1246 | ||
8feae131 DH |
1247 | /* we've found a region we can share */ |
1248 | atomic_inc(&pregion->vm_usage); | |
1249 | vma->vm_region = pregion; | |
1250 | start = pregion->vm_start; | |
1251 | start += (pgoff - pregion->vm_pgoff) << PAGE_SHIFT; | |
1252 | vma->vm_start = start; | |
1253 | vma->vm_end = start + len; | |
1254 | ||
1255 | if (pregion->vm_flags & VM_MAPPED_COPY) { | |
1256 | kdebug("share copy"); | |
1257 | vma->vm_flags |= VM_MAPPED_COPY; | |
1258 | } else { | |
1259 | kdebug("share mmap"); | |
1260 | ret = do_mmap_shared_file(vma); | |
1261 | if (ret < 0) { | |
1262 | vma->vm_region = NULL; | |
1263 | vma->vm_start = 0; | |
1264 | vma->vm_end = 0; | |
1265 | atomic_dec(&pregion->vm_usage); | |
1266 | pregion = NULL; | |
1267 | goto error_just_free; | |
1268 | } | |
1269 | } | |
1270 | fput(region->vm_file); | |
1271 | kmem_cache_free(vm_region_jar, region); | |
1272 | region = pregion; | |
1273 | result = start; | |
1274 | goto share; | |
1da177e4 LT |
1275 | } |
1276 | ||
1da177e4 LT |
1277 | /* obtain the address at which to make a shared mapping |
1278 | * - this is the hook for quasi-memory character devices to | |
1279 | * tell us the location of a shared mapping | |
1280 | */ | |
1281 | if (file && file->f_op->get_unmapped_area) { | |
1282 | addr = file->f_op->get_unmapped_area(file, addr, len, | |
1283 | pgoff, flags); | |
1284 | if (IS_ERR((void *) addr)) { | |
1285 | ret = addr; | |
1286 | if (ret != (unsigned long) -ENOSYS) | |
8feae131 | 1287 | goto error_just_free; |
1da177e4 LT |
1288 | |
1289 | /* the driver refused to tell us where to site | |
1290 | * the mapping so we'll have to attempt to copy | |
1291 | * it */ | |
1292 | ret = (unsigned long) -ENODEV; | |
1293 | if (!(capabilities & BDI_CAP_MAP_COPY)) | |
8feae131 | 1294 | goto error_just_free; |
1da177e4 LT |
1295 | |
1296 | capabilities &= ~BDI_CAP_MAP_DIRECT; | |
8feae131 DH |
1297 | } else { |
1298 | vma->vm_start = region->vm_start = addr; | |
1299 | vma->vm_end = region->vm_end = addr + len; | |
1da177e4 LT |
1300 | } |
1301 | } | |
1302 | } | |
1303 | ||
8feae131 | 1304 | vma->vm_region = region; |
1da177e4 LT |
1305 | |
1306 | /* set up the mapping */ | |
1307 | if (file && vma->vm_flags & VM_SHARED) | |
8feae131 | 1308 | ret = do_mmap_shared_file(vma); |
1da177e4 | 1309 | else |
8feae131 | 1310 | ret = do_mmap_private(vma, region, len); |
1da177e4 | 1311 | if (ret < 0) |
8feae131 DH |
1312 | goto error_put_region; |
1313 | ||
1314 | add_nommu_region(region); | |
1da177e4 LT |
1315 | |
1316 | /* okay... we have a mapping; now we have to register it */ | |
8feae131 | 1317 | result = vma->vm_start; |
1da177e4 | 1318 | |
1da177e4 LT |
1319 | current->mm->total_vm += len >> PAGE_SHIFT; |
1320 | ||
8feae131 DH |
1321 | share: |
1322 | add_vma_to_mm(current->mm, vma); | |
1da177e4 | 1323 | |
8feae131 | 1324 | up_write(&nommu_region_sem); |
1da177e4 LT |
1325 | |
1326 | if (prot & PROT_EXEC) | |
8feae131 | 1327 | flush_icache_range(result, result + len); |
1da177e4 | 1328 | |
8feae131 DH |
1329 | kleave(" = %lx", result); |
1330 | return result; | |
1da177e4 | 1331 | |
8feae131 DH |
1332 | error_put_region: |
1333 | __put_nommu_region(region); | |
1da177e4 | 1334 | if (vma) { |
925d1c40 | 1335 | if (vma->vm_file) { |
3fcd03e0 | 1336 | fput(vma->vm_file); |
925d1c40 MH |
1337 | if (vma->vm_flags & VM_EXECUTABLE) |
1338 | removed_exe_file_vma(vma->vm_mm); | |
1339 | } | |
8feae131 | 1340 | kmem_cache_free(vm_area_cachep, vma); |
1da177e4 | 1341 | } |
8feae131 | 1342 | kleave(" = %d [pr]", ret); |
1da177e4 LT |
1343 | return ret; |
1344 | ||
8feae131 DH |
1345 | error_just_free: |
1346 | up_write(&nommu_region_sem); | |
1347 | error: | |
1348 | fput(region->vm_file); | |
1349 | kmem_cache_free(vm_region_jar, region); | |
1350 | fput(vma->vm_file); | |
1351 | if (vma->vm_flags & VM_EXECUTABLE) | |
1352 | removed_exe_file_vma(vma->vm_mm); | |
1353 | kmem_cache_free(vm_area_cachep, vma); | |
1354 | kleave(" = %d", ret); | |
1355 | return ret; | |
1356 | ||
1357 | sharing_violation: | |
1358 | up_write(&nommu_region_sem); | |
1359 | printk(KERN_WARNING "Attempt to share mismatched mappings\n"); | |
1360 | ret = -EINVAL; | |
1361 | goto error; | |
1da177e4 | 1362 | |
8feae131 DH |
1363 | error_getting_vma: |
1364 | kmem_cache_free(vm_region_jar, region); | |
1365 | printk(KERN_WARNING "Allocation of vma for %lu byte allocation" | |
1366 | " from process %d failed\n", | |
1da177e4 LT |
1367 | len, current->pid); |
1368 | show_free_areas(); | |
1369 | return -ENOMEM; | |
1370 | ||
8feae131 DH |
1371 | error_getting_region: |
1372 | printk(KERN_WARNING "Allocation of vm region for %lu byte allocation" | |
1373 | " from process %d failed\n", | |
1da177e4 LT |
1374 | len, current->pid); |
1375 | show_free_areas(); | |
1376 | return -ENOMEM; | |
1377 | } | |
b5073173 | 1378 | EXPORT_SYMBOL(do_mmap_pgoff); |
1da177e4 LT |
1379 | |
1380 | /* | |
8feae131 DH |
1381 | * split a vma into two pieces at address 'addr', a new vma is allocated either |
1382 | * for the first part or the tail. | |
1da177e4 | 1383 | */ |
8feae131 DH |
1384 | int split_vma(struct mm_struct *mm, struct vm_area_struct *vma, |
1385 | unsigned long addr, int new_below) | |
1da177e4 | 1386 | { |
8feae131 DH |
1387 | struct vm_area_struct *new; |
1388 | struct vm_region *region; | |
1389 | unsigned long npages; | |
1da177e4 | 1390 | |
8feae131 | 1391 | kenter(""); |
1da177e4 | 1392 | |
8feae131 DH |
1393 | /* we're only permitted to split anonymous regions that have a single |
1394 | * owner */ | |
1395 | if (vma->vm_file || | |
1396 | atomic_read(&vma->vm_region->vm_usage) != 1) | |
1397 | return -ENOMEM; | |
1da177e4 | 1398 | |
8feae131 DH |
1399 | if (mm->map_count >= sysctl_max_map_count) |
1400 | return -ENOMEM; | |
1da177e4 | 1401 | |
8feae131 DH |
1402 | region = kmem_cache_alloc(vm_region_jar, GFP_KERNEL); |
1403 | if (!region) | |
1404 | return -ENOMEM; | |
1da177e4 | 1405 | |
8feae131 DH |
1406 | new = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL); |
1407 | if (!new) { | |
1408 | kmem_cache_free(vm_region_jar, region); | |
1409 | return -ENOMEM; | |
1410 | } | |
1411 | ||
1412 | /* most fields are the same, copy all, and then fixup */ | |
1413 | *new = *vma; | |
1414 | *region = *vma->vm_region; | |
1415 | new->vm_region = region; | |
1416 | ||
1417 | npages = (addr - vma->vm_start) >> PAGE_SHIFT; | |
1418 | ||
1419 | if (new_below) { | |
dd8632a1 | 1420 | region->vm_top = region->vm_end = new->vm_end = addr; |
8feae131 DH |
1421 | } else { |
1422 | region->vm_start = new->vm_start = addr; | |
1423 | region->vm_pgoff = new->vm_pgoff += npages; | |
1da177e4 | 1424 | } |
8feae131 DH |
1425 | |
1426 | if (new->vm_ops && new->vm_ops->open) | |
1427 | new->vm_ops->open(new); | |
1428 | ||
1429 | delete_vma_from_mm(vma); | |
1430 | down_write(&nommu_region_sem); | |
1431 | delete_nommu_region(vma->vm_region); | |
1432 | if (new_below) { | |
1433 | vma->vm_region->vm_start = vma->vm_start = addr; | |
1434 | vma->vm_region->vm_pgoff = vma->vm_pgoff += npages; | |
1435 | } else { | |
1436 | vma->vm_region->vm_end = vma->vm_end = addr; | |
dd8632a1 | 1437 | vma->vm_region->vm_top = addr; |
8feae131 DH |
1438 | } |
1439 | add_nommu_region(vma->vm_region); | |
1440 | add_nommu_region(new->vm_region); | |
1441 | up_write(&nommu_region_sem); | |
1442 | add_vma_to_mm(mm, vma); | |
1443 | add_vma_to_mm(mm, new); | |
1444 | return 0; | |
1da177e4 LT |
1445 | } |
1446 | ||
3034097a | 1447 | /* |
8feae131 DH |
1448 | * shrink a VMA by removing the specified chunk from either the beginning or |
1449 | * the end | |
3034097a | 1450 | */ |
8feae131 DH |
1451 | static int shrink_vma(struct mm_struct *mm, |
1452 | struct vm_area_struct *vma, | |
1453 | unsigned long from, unsigned long to) | |
1da177e4 | 1454 | { |
8feae131 | 1455 | struct vm_region *region; |
1da177e4 | 1456 | |
8feae131 | 1457 | kenter(""); |
1da177e4 | 1458 | |
8feae131 DH |
1459 | /* adjust the VMA's pointers, which may reposition it in the MM's tree |
1460 | * and list */ | |
1461 | delete_vma_from_mm(vma); | |
1462 | if (from > vma->vm_start) | |
1463 | vma->vm_end = from; | |
1464 | else | |
1465 | vma->vm_start = to; | |
1466 | add_vma_to_mm(mm, vma); | |
1da177e4 | 1467 | |
8feae131 DH |
1468 | /* cut the backing region down to size */ |
1469 | region = vma->vm_region; | |
1470 | BUG_ON(atomic_read(®ion->vm_usage) != 1); | |
1471 | ||
1472 | down_write(&nommu_region_sem); | |
1473 | delete_nommu_region(region); | |
dd8632a1 PM |
1474 | if (from > region->vm_start) { |
1475 | to = region->vm_top; | |
1476 | region->vm_top = region->vm_end = from; | |
1477 | } else { | |
8feae131 | 1478 | region->vm_start = to; |
dd8632a1 | 1479 | } |
8feae131 DH |
1480 | add_nommu_region(region); |
1481 | up_write(&nommu_region_sem); | |
1482 | ||
1483 | free_page_series(from, to); | |
1484 | return 0; | |
1485 | } | |
1da177e4 | 1486 | |
8feae131 DH |
1487 | /* |
1488 | * release a mapping | |
1489 | * - under NOMMU conditions the chunk to be unmapped must be backed by a single | |
1490 | * VMA, though it need not cover the whole VMA | |
1491 | */ | |
1492 | int do_munmap(struct mm_struct *mm, unsigned long start, size_t len) | |
1493 | { | |
1494 | struct vm_area_struct *vma; | |
1495 | struct rb_node *rb; | |
1496 | unsigned long end = start + len; | |
1497 | int ret; | |
1da177e4 | 1498 | |
8feae131 | 1499 | kenter(",%lx,%zx", start, len); |
1da177e4 | 1500 | |
8feae131 DH |
1501 | if (len == 0) |
1502 | return -EINVAL; | |
365e9c87 | 1503 | |
8feae131 DH |
1504 | /* find the first potentially overlapping VMA */ |
1505 | vma = find_vma(mm, start); | |
1506 | if (!vma) { | |
1507 | printk(KERN_WARNING | |
1508 | "munmap of memory not mmapped by process %d (%s):" | |
1509 | " 0x%lx-0x%lx\n", | |
1510 | current->pid, current->comm, start, start + len - 1); | |
1511 | return -EINVAL; | |
1512 | } | |
1da177e4 | 1513 | |
8feae131 DH |
1514 | /* we're allowed to split an anonymous VMA but not a file-backed one */ |
1515 | if (vma->vm_file) { | |
1516 | do { | |
1517 | if (start > vma->vm_start) { | |
1518 | kleave(" = -EINVAL [miss]"); | |
1519 | return -EINVAL; | |
1520 | } | |
1521 | if (end == vma->vm_end) | |
1522 | goto erase_whole_vma; | |
1523 | rb = rb_next(&vma->vm_rb); | |
1524 | vma = rb_entry(rb, struct vm_area_struct, vm_rb); | |
1525 | } while (rb); | |
1526 | kleave(" = -EINVAL [split file]"); | |
1527 | return -EINVAL; | |
1528 | } else { | |
1529 | /* the chunk must be a subset of the VMA found */ | |
1530 | if (start == vma->vm_start && end == vma->vm_end) | |
1531 | goto erase_whole_vma; | |
1532 | if (start < vma->vm_start || end > vma->vm_end) { | |
1533 | kleave(" = -EINVAL [superset]"); | |
1534 | return -EINVAL; | |
1535 | } | |
1536 | if (start & ~PAGE_MASK) { | |
1537 | kleave(" = -EINVAL [unaligned start]"); | |
1538 | return -EINVAL; | |
1539 | } | |
1540 | if (end != vma->vm_end && end & ~PAGE_MASK) { | |
1541 | kleave(" = -EINVAL [unaligned split]"); | |
1542 | return -EINVAL; | |
1543 | } | |
1544 | if (start != vma->vm_start && end != vma->vm_end) { | |
1545 | ret = split_vma(mm, vma, start, 1); | |
1546 | if (ret < 0) { | |
1547 | kleave(" = %d [split]", ret); | |
1548 | return ret; | |
1549 | } | |
1550 | } | |
1551 | return shrink_vma(mm, vma, start, end); | |
1552 | } | |
1da177e4 | 1553 | |
8feae131 DH |
1554 | erase_whole_vma: |
1555 | delete_vma_from_mm(vma); | |
1556 | delete_vma(mm, vma); | |
1557 | kleave(" = 0"); | |
1da177e4 LT |
1558 | return 0; |
1559 | } | |
b5073173 | 1560 | EXPORT_SYMBOL(do_munmap); |
1da177e4 | 1561 | |
3034097a DH |
1562 | asmlinkage long sys_munmap(unsigned long addr, size_t len) |
1563 | { | |
1564 | int ret; | |
1565 | struct mm_struct *mm = current->mm; | |
1566 | ||
1567 | down_write(&mm->mmap_sem); | |
1568 | ret = do_munmap(mm, addr, len); | |
1569 | up_write(&mm->mmap_sem); | |
1570 | return ret; | |
1571 | } | |
1572 | ||
1573 | /* | |
8feae131 | 1574 | * release all the mappings made in a process's VM space |
3034097a | 1575 | */ |
8feae131 | 1576 | void exit_mmap(struct mm_struct *mm) |
1da177e4 | 1577 | { |
8feae131 | 1578 | struct vm_area_struct *vma; |
1da177e4 | 1579 | |
8feae131 DH |
1580 | if (!mm) |
1581 | return; | |
1da177e4 | 1582 | |
8feae131 | 1583 | kenter(""); |
1da177e4 | 1584 | |
8feae131 | 1585 | mm->total_vm = 0; |
1da177e4 | 1586 | |
8feae131 DH |
1587 | while ((vma = mm->mmap)) { |
1588 | mm->mmap = vma->vm_next; | |
1589 | delete_vma_from_mm(vma); | |
1590 | delete_vma(mm, vma); | |
1da177e4 | 1591 | } |
8feae131 DH |
1592 | |
1593 | kleave(""); | |
1da177e4 LT |
1594 | } |
1595 | ||
1da177e4 LT |
1596 | unsigned long do_brk(unsigned long addr, unsigned long len) |
1597 | { | |
1598 | return -ENOMEM; | |
1599 | } | |
1600 | ||
1601 | /* | |
6fa5f80b DH |
1602 | * expand (or shrink) an existing mapping, potentially moving it at the same |
1603 | * time (controlled by the MREMAP_MAYMOVE flag and available VM space) | |
1da177e4 | 1604 | * |
6fa5f80b | 1605 | * under NOMMU conditions, we only permit changing a mapping's size, and only |
8feae131 DH |
1606 | * as long as it stays within the region allocated by do_mmap_private() and the |
1607 | * block is not shareable | |
1da177e4 | 1608 | * |
6fa5f80b | 1609 | * MREMAP_FIXED is not supported under NOMMU conditions |
1da177e4 LT |
1610 | */ |
1611 | unsigned long do_mremap(unsigned long addr, | |
1612 | unsigned long old_len, unsigned long new_len, | |
1613 | unsigned long flags, unsigned long new_addr) | |
1614 | { | |
6fa5f80b | 1615 | struct vm_area_struct *vma; |
1da177e4 LT |
1616 | |
1617 | /* insanity checks first */ | |
8feae131 | 1618 | if (old_len == 0 || new_len == 0) |
1da177e4 LT |
1619 | return (unsigned long) -EINVAL; |
1620 | ||
8feae131 DH |
1621 | if (addr & ~PAGE_MASK) |
1622 | return -EINVAL; | |
1623 | ||
1da177e4 LT |
1624 | if (flags & MREMAP_FIXED && new_addr != addr) |
1625 | return (unsigned long) -EINVAL; | |
1626 | ||
8feae131 | 1627 | vma = find_vma_exact(current->mm, addr, old_len); |
6fa5f80b DH |
1628 | if (!vma) |
1629 | return (unsigned long) -EINVAL; | |
1da177e4 | 1630 | |
6fa5f80b | 1631 | if (vma->vm_end != vma->vm_start + old_len) |
1da177e4 LT |
1632 | return (unsigned long) -EFAULT; |
1633 | ||
6fa5f80b | 1634 | if (vma->vm_flags & VM_MAYSHARE) |
1da177e4 LT |
1635 | return (unsigned long) -EPERM; |
1636 | ||
8feae131 | 1637 | if (new_len > vma->vm_region->vm_end - vma->vm_region->vm_start) |
1da177e4 LT |
1638 | return (unsigned long) -ENOMEM; |
1639 | ||
1640 | /* all checks complete - do it */ | |
6fa5f80b | 1641 | vma->vm_end = vma->vm_start + new_len; |
6fa5f80b DH |
1642 | return vma->vm_start; |
1643 | } | |
b5073173 | 1644 | EXPORT_SYMBOL(do_mremap); |
6fa5f80b | 1645 | |
8feae131 DH |
1646 | asmlinkage |
1647 | unsigned long sys_mremap(unsigned long addr, | |
1648 | unsigned long old_len, unsigned long new_len, | |
1649 | unsigned long flags, unsigned long new_addr) | |
6fa5f80b DH |
1650 | { |
1651 | unsigned long ret; | |
1652 | ||
1653 | down_write(¤t->mm->mmap_sem); | |
1654 | ret = do_mremap(addr, old_len, new_len, flags, new_addr); | |
1655 | up_write(¤t->mm->mmap_sem); | |
1656 | return ret; | |
1da177e4 LT |
1657 | } |
1658 | ||
6aab341e | 1659 | struct page *follow_page(struct vm_area_struct *vma, unsigned long address, |
deceb6cd | 1660 | unsigned int foll_flags) |
1da177e4 LT |
1661 | { |
1662 | return NULL; | |
1663 | } | |
1664 | ||
1da177e4 LT |
1665 | int remap_pfn_range(struct vm_area_struct *vma, unsigned long from, |
1666 | unsigned long to, unsigned long size, pgprot_t prot) | |
1667 | { | |
66aa2b4b GU |
1668 | vma->vm_start = vma->vm_pgoff << PAGE_SHIFT; |
1669 | return 0; | |
1da177e4 | 1670 | } |
22c4af40 | 1671 | EXPORT_SYMBOL(remap_pfn_range); |
1da177e4 | 1672 | |
f905bc44 PM |
1673 | int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, |
1674 | unsigned long pgoff) | |
1675 | { | |
1676 | unsigned int size = vma->vm_end - vma->vm_start; | |
1677 | ||
1678 | if (!(vma->vm_flags & VM_USERMAP)) | |
1679 | return -EINVAL; | |
1680 | ||
1681 | vma->vm_start = (unsigned long)(addr + (pgoff << PAGE_SHIFT)); | |
1682 | vma->vm_end = vma->vm_start + size; | |
1683 | ||
1684 | return 0; | |
1685 | } | |
1686 | EXPORT_SYMBOL(remap_vmalloc_range); | |
1687 | ||
1da177e4 LT |
1688 | void swap_unplug_io_fn(struct backing_dev_info *bdi, struct page *page) |
1689 | { | |
1690 | } | |
1691 | ||
1692 | unsigned long arch_get_unmapped_area(struct file *file, unsigned long addr, | |
1693 | unsigned long len, unsigned long pgoff, unsigned long flags) | |
1694 | { | |
1695 | return -ENOMEM; | |
1696 | } | |
1697 | ||
1363c3cd | 1698 | void arch_unmap_area(struct mm_struct *mm, unsigned long addr) |
1da177e4 LT |
1699 | { |
1700 | } | |
1701 | ||
1da177e4 LT |
1702 | void unmap_mapping_range(struct address_space *mapping, |
1703 | loff_t const holebegin, loff_t const holelen, | |
1704 | int even_cows) | |
1705 | { | |
1706 | } | |
22c4af40 | 1707 | EXPORT_SYMBOL(unmap_mapping_range); |
1da177e4 | 1708 | |
d56e03cd DH |
1709 | /* |
1710 | * ask for an unmapped area at which to create a mapping on a file | |
1711 | */ | |
1712 | unsigned long get_unmapped_area(struct file *file, unsigned long addr, | |
1713 | unsigned long len, unsigned long pgoff, | |
1714 | unsigned long flags) | |
1715 | { | |
1716 | unsigned long (*get_area)(struct file *, unsigned long, unsigned long, | |
1717 | unsigned long, unsigned long); | |
1718 | ||
1719 | get_area = current->mm->get_unmapped_area; | |
1720 | if (file && file->f_op && file->f_op->get_unmapped_area) | |
1721 | get_area = file->f_op->get_unmapped_area; | |
1722 | ||
1723 | if (!get_area) | |
1724 | return -ENOSYS; | |
1725 | ||
1726 | return get_area(file, addr, len, pgoff, flags); | |
1727 | } | |
d56e03cd DH |
1728 | EXPORT_SYMBOL(get_unmapped_area); |
1729 | ||
1da177e4 LT |
1730 | /* |
1731 | * Check that a process has enough memory to allocate a new virtual | |
1732 | * mapping. 0 means there is enough memory for the allocation to | |
1733 | * succeed and -ENOMEM implies there is not. | |
1734 | * | |
1735 | * We currently support three overcommit policies, which are set via the | |
1736 | * vm.overcommit_memory sysctl. See Documentation/vm/overcommit-accounting | |
1737 | * | |
1738 | * Strict overcommit modes added 2002 Feb 26 by Alan Cox. | |
1739 | * Additional code 2002 Jul 20 by Robert Love. | |
1740 | * | |
1741 | * cap_sys_admin is 1 if the process has admin privileges, 0 otherwise. | |
1742 | * | |
1743 | * Note this is a helper function intended to be used by LSMs which | |
1744 | * wish to use this logic. | |
1745 | */ | |
34b4e4aa | 1746 | int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin) |
1da177e4 LT |
1747 | { |
1748 | unsigned long free, allowed; | |
1749 | ||
1750 | vm_acct_memory(pages); | |
1751 | ||
1752 | /* | |
1753 | * Sometimes we want to use more memory than we have | |
1754 | */ | |
1755 | if (sysctl_overcommit_memory == OVERCOMMIT_ALWAYS) | |
1756 | return 0; | |
1757 | ||
1758 | if (sysctl_overcommit_memory == OVERCOMMIT_GUESS) { | |
1759 | unsigned long n; | |
1760 | ||
347ce434 | 1761 | free = global_page_state(NR_FILE_PAGES); |
1da177e4 LT |
1762 | free += nr_swap_pages; |
1763 | ||
1764 | /* | |
1765 | * Any slabs which are created with the | |
1766 | * SLAB_RECLAIM_ACCOUNT flag claim to have contents | |
1767 | * which are reclaimable, under pressure. The dentry | |
1768 | * cache and most inode caches should fall into this | |
1769 | */ | |
972d1a7b | 1770 | free += global_page_state(NR_SLAB_RECLAIMABLE); |
1da177e4 LT |
1771 | |
1772 | /* | |
1773 | * Leave the last 3% for root | |
1774 | */ | |
1775 | if (!cap_sys_admin) | |
1776 | free -= free / 32; | |
1777 | ||
1778 | if (free > pages) | |
1779 | return 0; | |
1780 | ||
1781 | /* | |
1782 | * nr_free_pages() is very expensive on large systems, | |
1783 | * only call if we're about to fail. | |
1784 | */ | |
1785 | n = nr_free_pages(); | |
d5ddc79b HA |
1786 | |
1787 | /* | |
1788 | * Leave reserved pages. The pages are not for anonymous pages. | |
1789 | */ | |
1790 | if (n <= totalreserve_pages) | |
1791 | goto error; | |
1792 | else | |
1793 | n -= totalreserve_pages; | |
1794 | ||
1795 | /* | |
1796 | * Leave the last 3% for root | |
1797 | */ | |
1da177e4 LT |
1798 | if (!cap_sys_admin) |
1799 | n -= n / 32; | |
1800 | free += n; | |
1801 | ||
1802 | if (free > pages) | |
1803 | return 0; | |
d5ddc79b HA |
1804 | |
1805 | goto error; | |
1da177e4 LT |
1806 | } |
1807 | ||
1808 | allowed = totalram_pages * sysctl_overcommit_ratio / 100; | |
1809 | /* | |
1810 | * Leave the last 3% for root | |
1811 | */ | |
1812 | if (!cap_sys_admin) | |
1813 | allowed -= allowed / 32; | |
1814 | allowed += total_swap_pages; | |
1815 | ||
1816 | /* Don't let a single process grow too big: | |
1817 | leave 3% of the size of this process for other processes */ | |
731572d3 AC |
1818 | if (mm) |
1819 | allowed -= mm->total_vm / 32; | |
1da177e4 | 1820 | |
2f60f8d3 SD |
1821 | /* |
1822 | * cast `allowed' as a signed long because vm_committed_space | |
1823 | * sometimes has a negative value | |
1824 | */ | |
80119ef5 | 1825 | if (atomic_long_read(&vm_committed_space) < (long)allowed) |
1da177e4 | 1826 | return 0; |
d5ddc79b | 1827 | error: |
1da177e4 LT |
1828 | vm_unacct_memory(pages); |
1829 | ||
1830 | return -ENOMEM; | |
1831 | } | |
1832 | ||
1833 | int in_gate_area_no_task(unsigned long addr) | |
1834 | { | |
1835 | return 0; | |
1836 | } | |
b0e15190 | 1837 | |
d0217ac0 | 1838 | int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
b0e15190 DH |
1839 | { |
1840 | BUG(); | |
d0217ac0 | 1841 | return 0; |
b0e15190 | 1842 | } |
b5073173 | 1843 | EXPORT_SYMBOL(filemap_fault); |
0ec76a11 DH |
1844 | |
1845 | /* | |
1846 | * Access another process' address space. | |
1847 | * - source/target buffer must be kernel space | |
1848 | */ | |
1849 | int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write) | |
1850 | { | |
0ec76a11 DH |
1851 | struct vm_area_struct *vma; |
1852 | struct mm_struct *mm; | |
1853 | ||
1854 | if (addr + len < addr) | |
1855 | return 0; | |
1856 | ||
1857 | mm = get_task_mm(tsk); | |
1858 | if (!mm) | |
1859 | return 0; | |
1860 | ||
1861 | down_read(&mm->mmap_sem); | |
1862 | ||
1863 | /* the access must start within one of the target process's mappings */ | |
0159b141 DH |
1864 | vma = find_vma(mm, addr); |
1865 | if (vma) { | |
0ec76a11 DH |
1866 | /* don't overrun this mapping */ |
1867 | if (addr + len >= vma->vm_end) | |
1868 | len = vma->vm_end - addr; | |
1869 | ||
1870 | /* only read or write mappings where it is permitted */ | |
d00c7b99 | 1871 | if (write && vma->vm_flags & VM_MAYWRITE) |
0ec76a11 | 1872 | len -= copy_to_user((void *) addr, buf, len); |
d00c7b99 | 1873 | else if (!write && vma->vm_flags & VM_MAYREAD) |
0ec76a11 DH |
1874 | len -= copy_from_user(buf, (void *) addr, len); |
1875 | else | |
1876 | len = 0; | |
1877 | } else { | |
1878 | len = 0; | |
1879 | } | |
1880 | ||
1881 | up_read(&mm->mmap_sem); | |
1882 | mmput(mm); | |
1883 | return len; | |
1884 | } |