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457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * linux/mm/nommu.c | |
4 | * | |
5 | * Replacement code for mm functions to support CPU's that don't | |
6 | * have any form of memory management unit (thus no virtual memory). | |
7 | * | |
dd19d293 | 8 | * See Documentation/admin-guide/mm/nommu-mmap.rst |
1da177e4 | 9 | * |
8feae131 | 10 | * Copyright (c) 2004-2008 David Howells <[email protected]> |
1da177e4 LT |
11 | * Copyright (c) 2000-2003 David McCullough <[email protected]> |
12 | * Copyright (c) 2000-2001 D Jeff Dionne <[email protected]> | |
13 | * Copyright (c) 2002 Greg Ungerer <[email protected]> | |
29c185e5 | 14 | * Copyright (c) 2007-2010 Paul Mundt <[email protected]> |
1da177e4 LT |
15 | */ |
16 | ||
b1de0d13 MH |
17 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
18 | ||
b95f1b31 | 19 | #include <linux/export.h> |
1da177e4 | 20 | #include <linux/mm.h> |
6e84f315 | 21 | #include <linux/sched/mm.h> |
1da177e4 LT |
22 | #include <linux/mman.h> |
23 | #include <linux/swap.h> | |
24 | #include <linux/file.h> | |
25 | #include <linux/highmem.h> | |
26 | #include <linux/pagemap.h> | |
27 | #include <linux/slab.h> | |
28 | #include <linux/vmalloc.h> | |
1da177e4 | 29 | #include <linux/backing-dev.h> |
3b32123d | 30 | #include <linux/compiler.h> |
1da177e4 LT |
31 | #include <linux/mount.h> |
32 | #include <linux/personality.h> | |
33 | #include <linux/security.h> | |
34 | #include <linux/syscalls.h> | |
120a795d | 35 | #include <linux/audit.h> |
b1de0d13 | 36 | #include <linux/printk.h> |
1da177e4 | 37 | |
7c0f6ba6 | 38 | #include <linux/uaccess.h> |
4c91c07c | 39 | #include <linux/uio.h> |
1da177e4 LT |
40 | #include <asm/tlb.h> |
41 | #include <asm/tlbflush.h> | |
eb8cdec4 | 42 | #include <asm/mmu_context.h> |
8feae131 DH |
43 | #include "internal.h" |
44 | ||
1da177e4 | 45 | void *high_memory; |
944b6874 | 46 | EXPORT_SYMBOL(high_memory); |
1da177e4 LT |
47 | struct page *mem_map; |
48 | unsigned long max_mapnr; | |
5b8bf307 | 49 | EXPORT_SYMBOL(max_mapnr); |
4266c97a | 50 | unsigned long highest_memmap_pfn; |
fc4d5c29 | 51 | int sysctl_nr_trim_pages = CONFIG_NOMMU_INITIAL_TRIM_EXCESS; |
1da177e4 LT |
52 | int heap_stack_gap = 0; |
53 | ||
33e5d769 | 54 | atomic_long_t mmap_pages_allocated; |
8feae131 | 55 | |
1da177e4 | 56 | EXPORT_SYMBOL(mem_map); |
1da177e4 | 57 | |
8feae131 DH |
58 | /* list of mapped, potentially shareable regions */ |
59 | static struct kmem_cache *vm_region_jar; | |
60 | struct rb_root nommu_region_tree = RB_ROOT; | |
61 | DECLARE_RWSEM(nommu_region_sem); | |
1da177e4 | 62 | |
f0f37e2f | 63 | const struct vm_operations_struct generic_file_vm_ops = { |
1da177e4 LT |
64 | }; |
65 | ||
1da177e4 LT |
66 | /* |
67 | * Return the total memory allocated for this pointer, not | |
68 | * just what the caller asked for. | |
69 | * | |
70 | * Doesn't have to be accurate, i.e. may have races. | |
71 | */ | |
72 | unsigned int kobjsize(const void *objp) | |
73 | { | |
74 | struct page *page; | |
75 | ||
4016a139 MH |
76 | /* |
77 | * If the object we have should not have ksize performed on it, | |
78 | * return size of 0 | |
79 | */ | |
5a1603be | 80 | if (!objp || !virt_addr_valid(objp)) |
6cfd53fc PM |
81 | return 0; |
82 | ||
83 | page = virt_to_head_page(objp); | |
6cfd53fc PM |
84 | |
85 | /* | |
86 | * If the allocator sets PageSlab, we know the pointer came from | |
87 | * kmalloc(). | |
88 | */ | |
1da177e4 LT |
89 | if (PageSlab(page)) |
90 | return ksize(objp); | |
91 | ||
ab2e83ea PM |
92 | /* |
93 | * If it's not a compound page, see if we have a matching VMA | |
94 | * region. This test is intentionally done in reverse order, | |
95 | * so if there's no VMA, we still fall through and hand back | |
96 | * PAGE_SIZE for 0-order pages. | |
97 | */ | |
98 | if (!PageCompound(page)) { | |
99 | struct vm_area_struct *vma; | |
100 | ||
101 | vma = find_vma(current->mm, (unsigned long)objp); | |
102 | if (vma) | |
103 | return vma->vm_end - vma->vm_start; | |
104 | } | |
105 | ||
6cfd53fc PM |
106 | /* |
107 | * The ksize() function is only guaranteed to work for pointers | |
5a1603be | 108 | * returned by kmalloc(). So handle arbitrary pointers here. |
6cfd53fc | 109 | */ |
a50b854e | 110 | return page_size(page); |
1da177e4 LT |
111 | } |
112 | ||
b3bdda02 | 113 | void vfree(const void *addr) |
1da177e4 LT |
114 | { |
115 | kfree(addr); | |
116 | } | |
b5073173 | 117 | EXPORT_SYMBOL(vfree); |
1da177e4 | 118 | |
88ae5fb7 | 119 | void *__vmalloc_noprof(unsigned long size, gfp_t gfp_mask) |
1da177e4 LT |
120 | { |
121 | /* | |
8518609d RD |
122 | * You can't specify __GFP_HIGHMEM with kmalloc() since kmalloc() |
123 | * returns only a logical address. | |
1da177e4 | 124 | */ |
88ae5fb7 | 125 | return kmalloc_noprof(size, (gfp_mask | __GFP_COMP) & ~__GFP_HIGHMEM); |
1da177e4 | 126 | } |
88ae5fb7 | 127 | EXPORT_SYMBOL(__vmalloc_noprof); |
1da177e4 | 128 | |
88ae5fb7 | 129 | void *__vmalloc_node_range_noprof(unsigned long size, unsigned long align, |
041de93f CH |
130 | unsigned long start, unsigned long end, gfp_t gfp_mask, |
131 | pgprot_t prot, unsigned long vm_flags, int node, | |
132 | const void *caller) | |
133 | { | |
88ae5fb7 | 134 | return __vmalloc_noprof(size, gfp_mask); |
041de93f CH |
135 | } |
136 | ||
88ae5fb7 | 137 | void *__vmalloc_node_noprof(unsigned long size, unsigned long align, gfp_t gfp_mask, |
2b905948 | 138 | int node, const void *caller) |
a7c3e901 | 139 | { |
88ae5fb7 | 140 | return __vmalloc_noprof(size, gfp_mask); |
a7c3e901 MH |
141 | } |
142 | ||
ed81745a | 143 | static void *__vmalloc_user_flags(unsigned long size, gfp_t flags) |
f905bc44 PM |
144 | { |
145 | void *ret; | |
146 | ||
88dca4ca | 147 | ret = __vmalloc(size, flags); |
f905bc44 PM |
148 | if (ret) { |
149 | struct vm_area_struct *vma; | |
150 | ||
d8ed45c5 | 151 | mmap_write_lock(current->mm); |
f905bc44 PM |
152 | vma = find_vma(current->mm, (unsigned long)ret); |
153 | if (vma) | |
1c71222e | 154 | vm_flags_set(vma, VM_USERMAP); |
d8ed45c5 | 155 | mmap_write_unlock(current->mm); |
f905bc44 PM |
156 | } |
157 | ||
158 | return ret; | |
159 | } | |
ed81745a | 160 | |
88ae5fb7 | 161 | void *vmalloc_user_noprof(unsigned long size) |
ed81745a AN |
162 | { |
163 | return __vmalloc_user_flags(size, GFP_KERNEL | __GFP_ZERO); | |
164 | } | |
88ae5fb7 | 165 | EXPORT_SYMBOL(vmalloc_user_noprof); |
f905bc44 | 166 | |
b3bdda02 | 167 | struct page *vmalloc_to_page(const void *addr) |
1da177e4 LT |
168 | { |
169 | return virt_to_page(addr); | |
170 | } | |
b5073173 | 171 | EXPORT_SYMBOL(vmalloc_to_page); |
1da177e4 | 172 | |
b3bdda02 | 173 | unsigned long vmalloc_to_pfn(const void *addr) |
1da177e4 LT |
174 | { |
175 | return page_to_pfn(virt_to_page(addr)); | |
176 | } | |
b5073173 | 177 | EXPORT_SYMBOL(vmalloc_to_pfn); |
1da177e4 | 178 | |
4c91c07c | 179 | long vread_iter(struct iov_iter *iter, const char *addr, size_t count) |
1da177e4 | 180 | { |
9bde916b | 181 | /* Don't allow overflow */ |
4c91c07c LS |
182 | if ((unsigned long) addr + count < count) |
183 | count = -(unsigned long) addr; | |
9bde916b | 184 | |
4c91c07c | 185 | return copy_to_iter(addr, count, iter); |
1da177e4 LT |
186 | } |
187 | ||
1da177e4 | 188 | /* |
e1c05067 | 189 | * vmalloc - allocate virtually contiguous memory |
1da177e4 LT |
190 | * |
191 | * @size: allocation size | |
192 | * | |
193 | * Allocate enough pages to cover @size from the page level | |
e1c05067 | 194 | * allocator and map them into contiguous kernel virtual space. |
1da177e4 | 195 | * |
c1c8897f | 196 | * For tight control over page level allocator and protection flags |
1da177e4 LT |
197 | * use __vmalloc() instead. |
198 | */ | |
88ae5fb7 | 199 | void *vmalloc_noprof(unsigned long size) |
1da177e4 | 200 | { |
88ae5fb7 | 201 | return __vmalloc_noprof(size, GFP_KERNEL); |
1da177e4 | 202 | } |
88ae5fb7 | 203 | EXPORT_SYMBOL(vmalloc_noprof); |
f6138882 | 204 | |
88ae5fb7 | 205 | void *vmalloc_huge_noprof(unsigned long size, gfp_t gfp_mask) __weak __alias(__vmalloc_noprof); |
0fc74d82 | 206 | |
e1ca7788 | 207 | /* |
e1c05067 | 208 | * vzalloc - allocate virtually contiguous memory with zero fill |
e1ca7788 DY |
209 | * |
210 | * @size: allocation size | |
211 | * | |
212 | * Allocate enough pages to cover @size from the page level | |
e1c05067 | 213 | * allocator and map them into contiguous kernel virtual space. |
e1ca7788 DY |
214 | * The memory allocated is set to zero. |
215 | * | |
216 | * For tight control over page level allocator and protection flags | |
217 | * use __vmalloc() instead. | |
218 | */ | |
88ae5fb7 | 219 | void *vzalloc_noprof(unsigned long size) |
e1ca7788 | 220 | { |
88ae5fb7 | 221 | return __vmalloc_noprof(size, GFP_KERNEL | __GFP_ZERO); |
e1ca7788 | 222 | } |
88ae5fb7 | 223 | EXPORT_SYMBOL(vzalloc_noprof); |
e1ca7788 DY |
224 | |
225 | /** | |
226 | * vmalloc_node - allocate memory on a specific node | |
227 | * @size: allocation size | |
228 | * @node: numa node | |
229 | * | |
230 | * Allocate enough pages to cover @size from the page level | |
231 | * allocator and map them into contiguous kernel virtual space. | |
232 | * | |
233 | * For tight control over page level allocator and protection flags | |
234 | * use __vmalloc() instead. | |
235 | */ | |
88ae5fb7 | 236 | void *vmalloc_node_noprof(unsigned long size, int node) |
f6138882 | 237 | { |
88ae5fb7 | 238 | return vmalloc_noprof(size); |
f6138882 | 239 | } |
88ae5fb7 | 240 | EXPORT_SYMBOL(vmalloc_node_noprof); |
e1ca7788 DY |
241 | |
242 | /** | |
243 | * vzalloc_node - allocate memory on a specific node with zero fill | |
244 | * @size: allocation size | |
245 | * @node: numa node | |
246 | * | |
247 | * Allocate enough pages to cover @size from the page level | |
248 | * allocator and map them into contiguous kernel virtual space. | |
249 | * The memory allocated is set to zero. | |
250 | * | |
251 | * For tight control over page level allocator and protection flags | |
252 | * use __vmalloc() instead. | |
253 | */ | |
88ae5fb7 | 254 | void *vzalloc_node_noprof(unsigned long size, int node) |
e1ca7788 | 255 | { |
88ae5fb7 | 256 | return vzalloc_noprof(size); |
e1ca7788 | 257 | } |
88ae5fb7 | 258 | EXPORT_SYMBOL(vzalloc_node_noprof); |
1da177e4 | 259 | |
b5073173 PM |
260 | /** |
261 | * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) | |
1da177e4 LT |
262 | * @size: allocation size |
263 | * | |
264 | * Allocate enough 32bit PA addressable pages to cover @size from the | |
e1c05067 | 265 | * page level allocator and map them into contiguous kernel virtual space. |
1da177e4 | 266 | */ |
88ae5fb7 | 267 | void *vmalloc_32_noprof(unsigned long size) |
1da177e4 | 268 | { |
88ae5fb7 | 269 | return __vmalloc_noprof(size, GFP_KERNEL); |
1da177e4 | 270 | } |
88ae5fb7 | 271 | EXPORT_SYMBOL(vmalloc_32_noprof); |
b5073173 PM |
272 | |
273 | /** | |
274 | * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory | |
275 | * @size: allocation size | |
276 | * | |
277 | * The resulting memory area is 32bit addressable and zeroed so it can be | |
278 | * mapped to userspace without leaking data. | |
f905bc44 PM |
279 | * |
280 | * VM_USERMAP is set on the corresponding VMA so that subsequent calls to | |
281 | * remap_vmalloc_range() are permissible. | |
b5073173 | 282 | */ |
88ae5fb7 | 283 | void *vmalloc_32_user_noprof(unsigned long size) |
b5073173 | 284 | { |
f905bc44 PM |
285 | /* |
286 | * We'll have to sort out the ZONE_DMA bits for 64-bit, | |
287 | * but for now this can simply use vmalloc_user() directly. | |
288 | */ | |
88ae5fb7 | 289 | return vmalloc_user_noprof(size); |
b5073173 | 290 | } |
88ae5fb7 | 291 | EXPORT_SYMBOL(vmalloc_32_user_noprof); |
1da177e4 LT |
292 | |
293 | void *vmap(struct page **pages, unsigned int count, unsigned long flags, pgprot_t prot) | |
294 | { | |
295 | BUG(); | |
296 | return NULL; | |
297 | } | |
b5073173 | 298 | EXPORT_SYMBOL(vmap); |
1da177e4 | 299 | |
b3bdda02 | 300 | void vunmap(const void *addr) |
1da177e4 LT |
301 | { |
302 | BUG(); | |
303 | } | |
b5073173 | 304 | EXPORT_SYMBOL(vunmap); |
1da177e4 | 305 | |
d4efd79a | 306 | void *vm_map_ram(struct page **pages, unsigned int count, int node) |
eb6434d9 PM |
307 | { |
308 | BUG(); | |
309 | return NULL; | |
310 | } | |
311 | EXPORT_SYMBOL(vm_map_ram); | |
312 | ||
313 | void vm_unmap_ram(const void *mem, unsigned int count) | |
314 | { | |
315 | BUG(); | |
316 | } | |
317 | EXPORT_SYMBOL(vm_unmap_ram); | |
318 | ||
319 | void vm_unmap_aliases(void) | |
320 | { | |
321 | } | |
322 | EXPORT_SYMBOL_GPL(vm_unmap_aliases); | |
323 | ||
29c185e5 PM |
324 | void free_vm_area(struct vm_struct *area) |
325 | { | |
326 | BUG(); | |
327 | } | |
328 | EXPORT_SYMBOL_GPL(free_vm_area); | |
329 | ||
b5073173 PM |
330 | int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, |
331 | struct page *page) | |
332 | { | |
333 | return -EINVAL; | |
334 | } | |
335 | EXPORT_SYMBOL(vm_insert_page); | |
336 | ||
62346c6c JA |
337 | int vm_insert_pages(struct vm_area_struct *vma, unsigned long addr, |
338 | struct page **pages, unsigned long *num) | |
339 | { | |
340 | return -EINVAL; | |
341 | } | |
342 | EXPORT_SYMBOL(vm_insert_pages); | |
343 | ||
a667d745 SJ |
344 | int vm_map_pages(struct vm_area_struct *vma, struct page **pages, |
345 | unsigned long num) | |
346 | { | |
347 | return -EINVAL; | |
348 | } | |
349 | EXPORT_SYMBOL(vm_map_pages); | |
350 | ||
351 | int vm_map_pages_zero(struct vm_area_struct *vma, struct page **pages, | |
352 | unsigned long num) | |
353 | { | |
354 | return -EINVAL; | |
355 | } | |
356 | EXPORT_SYMBOL(vm_map_pages_zero); | |
357 | ||
1da177e4 LT |
358 | /* |
359 | * sys_brk() for the most part doesn't need the global kernel | |
360 | * lock, except when an application is doing something nasty | |
361 | * like trying to un-brk an area that has already been mapped | |
362 | * to a regular file. in this case, the unmapping will need | |
363 | * to invoke file system routines that need the global lock. | |
364 | */ | |
6a6160a7 | 365 | SYSCALL_DEFINE1(brk, unsigned long, brk) |
1da177e4 LT |
366 | { |
367 | struct mm_struct *mm = current->mm; | |
368 | ||
369 | if (brk < mm->start_brk || brk > mm->context.end_brk) | |
370 | return mm->brk; | |
371 | ||
372 | if (mm->brk == brk) | |
373 | return mm->brk; | |
374 | ||
375 | /* | |
376 | * Always allow shrinking brk | |
377 | */ | |
378 | if (brk <= mm->brk) { | |
379 | mm->brk = brk; | |
380 | return brk; | |
381 | } | |
382 | ||
383 | /* | |
384 | * Ok, looks good - let it rip. | |
385 | */ | |
a75a2df6 | 386 | flush_icache_user_range(mm->brk, brk); |
1da177e4 LT |
387 | return mm->brk = brk; |
388 | } | |
389 | ||
8feae131 | 390 | /* |
3edf41d8 | 391 | * initialise the percpu counter for VM and region record slabs |
8feae131 DH |
392 | */ |
393 | void __init mmap_init(void) | |
1da177e4 | 394 | { |
00a62ce9 KM |
395 | int ret; |
396 | ||
908c7f19 | 397 | ret = percpu_counter_init(&vm_committed_as, 0, GFP_KERNEL); |
00a62ce9 | 398 | VM_BUG_ON(ret); |
5d097056 | 399 | vm_region_jar = KMEM_CACHE(vm_region, SLAB_PANIC|SLAB_ACCOUNT); |
1da177e4 | 400 | } |
1da177e4 | 401 | |
3034097a | 402 | /* |
8feae131 DH |
403 | * validate the region tree |
404 | * - the caller must hold the region lock | |
3034097a | 405 | */ |
8feae131 DH |
406 | #ifdef CONFIG_DEBUG_NOMMU_REGIONS |
407 | static noinline void validate_nommu_regions(void) | |
3034097a | 408 | { |
8feae131 DH |
409 | struct vm_region *region, *last; |
410 | struct rb_node *p, *lastp; | |
3034097a | 411 | |
8feae131 DH |
412 | lastp = rb_first(&nommu_region_tree); |
413 | if (!lastp) | |
414 | return; | |
415 | ||
416 | last = rb_entry(lastp, struct vm_region, vm_rb); | |
c9427bc0 GT |
417 | BUG_ON(last->vm_end <= last->vm_start); |
418 | BUG_ON(last->vm_top < last->vm_end); | |
8feae131 DH |
419 | |
420 | while ((p = rb_next(lastp))) { | |
421 | region = rb_entry(p, struct vm_region, vm_rb); | |
422 | last = rb_entry(lastp, struct vm_region, vm_rb); | |
423 | ||
c9427bc0 GT |
424 | BUG_ON(region->vm_end <= region->vm_start); |
425 | BUG_ON(region->vm_top < region->vm_end); | |
426 | BUG_ON(region->vm_start < last->vm_top); | |
3034097a | 427 | |
8feae131 DH |
428 | lastp = p; |
429 | } | |
3034097a | 430 | } |
8feae131 | 431 | #else |
33e5d769 DH |
432 | static void validate_nommu_regions(void) |
433 | { | |
434 | } | |
8feae131 | 435 | #endif |
3034097a DH |
436 | |
437 | /* | |
8feae131 | 438 | * add a region into the global tree |
3034097a | 439 | */ |
8feae131 | 440 | static void add_nommu_region(struct vm_region *region) |
3034097a | 441 | { |
8feae131 DH |
442 | struct vm_region *pregion; |
443 | struct rb_node **p, *parent; | |
3034097a | 444 | |
8feae131 DH |
445 | validate_nommu_regions(); |
446 | ||
8feae131 DH |
447 | parent = NULL; |
448 | p = &nommu_region_tree.rb_node; | |
449 | while (*p) { | |
450 | parent = *p; | |
451 | pregion = rb_entry(parent, struct vm_region, vm_rb); | |
452 | if (region->vm_start < pregion->vm_start) | |
453 | p = &(*p)->rb_left; | |
454 | else if (region->vm_start > pregion->vm_start) | |
455 | p = &(*p)->rb_right; | |
456 | else if (pregion == region) | |
457 | return; | |
458 | else | |
459 | BUG(); | |
3034097a DH |
460 | } |
461 | ||
8feae131 DH |
462 | rb_link_node(®ion->vm_rb, parent, p); |
463 | rb_insert_color(®ion->vm_rb, &nommu_region_tree); | |
3034097a | 464 | |
8feae131 | 465 | validate_nommu_regions(); |
3034097a | 466 | } |
3034097a | 467 | |
930e652a | 468 | /* |
8feae131 | 469 | * delete a region from the global tree |
930e652a | 470 | */ |
8feae131 | 471 | static void delete_nommu_region(struct vm_region *region) |
930e652a | 472 | { |
8feae131 | 473 | BUG_ON(!nommu_region_tree.rb_node); |
930e652a | 474 | |
8feae131 DH |
475 | validate_nommu_regions(); |
476 | rb_erase(®ion->vm_rb, &nommu_region_tree); | |
477 | validate_nommu_regions(); | |
57c8f63e GU |
478 | } |
479 | ||
6fa5f80b | 480 | /* |
8feae131 | 481 | * free a contiguous series of pages |
6fa5f80b | 482 | */ |
8feae131 | 483 | static void free_page_series(unsigned long from, unsigned long to) |
6fa5f80b | 484 | { |
8feae131 | 485 | for (; from < to; from += PAGE_SIZE) { |
9330723c | 486 | struct page *page = virt_to_page((void *)from); |
8feae131 | 487 | |
33e5d769 | 488 | atomic_long_dec(&mmap_pages_allocated); |
8feae131 | 489 | put_page(page); |
6fa5f80b | 490 | } |
6fa5f80b DH |
491 | } |
492 | ||
3034097a | 493 | /* |
8feae131 | 494 | * release a reference to a region |
33e5d769 | 495 | * - the caller must hold the region semaphore for writing, which this releases |
dd8632a1 | 496 | * - the region may not have been added to the tree yet, in which case vm_top |
8feae131 | 497 | * will equal vm_start |
3034097a | 498 | */ |
8feae131 DH |
499 | static void __put_nommu_region(struct vm_region *region) |
500 | __releases(nommu_region_sem) | |
1da177e4 | 501 | { |
8feae131 | 502 | BUG_ON(!nommu_region_tree.rb_node); |
1da177e4 | 503 | |
1e2ae599 | 504 | if (--region->vm_usage == 0) { |
dd8632a1 | 505 | if (region->vm_top > region->vm_start) |
8feae131 DH |
506 | delete_nommu_region(region); |
507 | up_write(&nommu_region_sem); | |
508 | ||
509 | if (region->vm_file) | |
510 | fput(region->vm_file); | |
511 | ||
512 | /* IO memory and memory shared directly out of the pagecache | |
513 | * from ramfs/tmpfs mustn't be released here */ | |
22cc877b | 514 | if (region->vm_flags & VM_MAPPED_COPY) |
dd8632a1 | 515 | free_page_series(region->vm_start, region->vm_top); |
8feae131 DH |
516 | kmem_cache_free(vm_region_jar, region); |
517 | } else { | |
518 | up_write(&nommu_region_sem); | |
1da177e4 | 519 | } |
8feae131 | 520 | } |
1da177e4 | 521 | |
8feae131 DH |
522 | /* |
523 | * release a reference to a region | |
524 | */ | |
525 | static void put_nommu_region(struct vm_region *region) | |
526 | { | |
527 | down_write(&nommu_region_sem); | |
528 | __put_nommu_region(region); | |
1da177e4 LT |
529 | } |
530 | ||
8220543d | 531 | static void setup_vma_to_mm(struct vm_area_struct *vma, struct mm_struct *mm) |
1da177e4 | 532 | { |
8feae131 | 533 | vma->vm_mm = mm; |
1da177e4 LT |
534 | |
535 | /* add the VMA to the mapping */ | |
536 | if (vma->vm_file) { | |
8220543d | 537 | struct address_space *mapping = vma->vm_file->f_mapping; |
1da177e4 | 538 | |
83cde9e8 | 539 | i_mmap_lock_write(mapping); |
1da177e4 | 540 | flush_dcache_mmap_lock(mapping); |
6b2dbba8 | 541 | vma_interval_tree_insert(vma, &mapping->i_mmap); |
1da177e4 | 542 | flush_dcache_mmap_unlock(mapping); |
83cde9e8 | 543 | i_mmap_unlock_write(mapping); |
1da177e4 | 544 | } |
8220543d | 545 | } |
1da177e4 | 546 | |
8220543d MWO |
547 | static void cleanup_vma_from_mm(struct vm_area_struct *vma) |
548 | { | |
7964cf8c | 549 | vma->vm_mm->map_count--; |
1da177e4 LT |
550 | /* remove the VMA from the mapping */ |
551 | if (vma->vm_file) { | |
7964cf8c | 552 | struct address_space *mapping; |
1da177e4 LT |
553 | mapping = vma->vm_file->f_mapping; |
554 | ||
83cde9e8 | 555 | i_mmap_lock_write(mapping); |
1da177e4 | 556 | flush_dcache_mmap_lock(mapping); |
6b2dbba8 | 557 | vma_interval_tree_remove(vma, &mapping->i_mmap); |
1da177e4 | 558 | flush_dcache_mmap_unlock(mapping); |
83cde9e8 | 559 | i_mmap_unlock_write(mapping); |
1da177e4 | 560 | } |
8220543d | 561 | } |
47d9644d | 562 | |
8220543d MWO |
563 | /* |
564 | * delete a VMA from its owning mm_struct and address space | |
565 | */ | |
566 | static int delete_vma_from_mm(struct vm_area_struct *vma) | |
567 | { | |
47d9644d | 568 | VMA_ITERATOR(vmi, vma->vm_mm, vma->vm_start); |
8220543d | 569 | |
b5df0922 LH |
570 | vma_iter_config(&vmi, vma->vm_start, vma->vm_end); |
571 | if (vma_iter_prealloc(&vmi, vma)) { | |
8220543d MWO |
572 | pr_warn("Allocation of vma tree for process %d failed\n", |
573 | current->pid); | |
574 | return -ENOMEM; | |
575 | } | |
576 | cleanup_vma_from_mm(vma); | |
1da177e4 | 577 | |
8feae131 | 578 | /* remove from the MM's tree and list */ |
b5df0922 | 579 | vma_iter_clear(&vmi); |
8220543d | 580 | return 0; |
8feae131 | 581 | } |
8feae131 DH |
582 | /* |
583 | * destroy a VMA record | |
584 | */ | |
585 | static void delete_vma(struct mm_struct *mm, struct vm_area_struct *vma) | |
586 | { | |
8feae131 DH |
587 | if (vma->vm_ops && vma->vm_ops->close) |
588 | vma->vm_ops->close(vma); | |
e9714acf | 589 | if (vma->vm_file) |
8feae131 | 590 | fput(vma->vm_file); |
8feae131 | 591 | put_nommu_region(vma->vm_region); |
3928d4f5 | 592 | vm_area_free(vma); |
8feae131 DH |
593 | } |
594 | ||
abdba2dd LH |
595 | struct vm_area_struct *find_vma_intersection(struct mm_struct *mm, |
596 | unsigned long start_addr, | |
597 | unsigned long end_addr) | |
598 | { | |
599 | unsigned long index = start_addr; | |
600 | ||
601 | mmap_assert_locked(mm); | |
602 | return mt_find(&mm->mm_mt, &index, end_addr - 1); | |
603 | } | |
604 | EXPORT_SYMBOL(find_vma_intersection); | |
605 | ||
8feae131 DH |
606 | /* |
607 | * look up the first VMA in which addr resides, NULL if none | |
c1e8d7c6 | 608 | * - should be called with mm->mmap_lock at least held readlocked |
8feae131 DH |
609 | */ |
610 | struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) | |
611 | { | |
47d9644d | 612 | VMA_ITERATOR(vmi, mm, addr); |
8feae131 | 613 | |
47d9644d | 614 | return vma_iter_load(&vmi); |
8feae131 DH |
615 | } |
616 | EXPORT_SYMBOL(find_vma); | |
617 | ||
d85a143b LT |
618 | /* |
619 | * At least xtensa ends up having protection faults even with no | |
620 | * MMU.. No stack expansion, at least. | |
621 | */ | |
622 | struct vm_area_struct *lock_mm_and_find_vma(struct mm_struct *mm, | |
623 | unsigned long addr, struct pt_regs *regs) | |
624 | { | |
03f88937 MF |
625 | struct vm_area_struct *vma; |
626 | ||
d85a143b | 627 | mmap_read_lock(mm); |
03f88937 MF |
628 | vma = vma_lookup(mm, addr); |
629 | if (!vma) | |
630 | mmap_read_unlock(mm); | |
631 | return vma; | |
d85a143b LT |
632 | } |
633 | ||
8feae131 DH |
634 | /* |
635 | * expand a stack to a given address | |
636 | * - not supported under NOMMU conditions | |
637 | */ | |
8d7071af | 638 | int expand_stack_locked(struct vm_area_struct *vma, unsigned long addr) |
8feae131 DH |
639 | { |
640 | return -ENOMEM; | |
641 | } | |
642 | ||
8d7071af LT |
643 | struct vm_area_struct *expand_stack(struct mm_struct *mm, unsigned long addr) |
644 | { | |
645 | mmap_read_unlock(mm); | |
646 | return NULL; | |
647 | } | |
648 | ||
8feae131 DH |
649 | /* |
650 | * look up the first VMA exactly that exactly matches addr | |
c1e8d7c6 | 651 | * - should be called with mm->mmap_lock at least held readlocked |
8feae131 DH |
652 | */ |
653 | static struct vm_area_struct *find_vma_exact(struct mm_struct *mm, | |
654 | unsigned long addr, | |
655 | unsigned long len) | |
656 | { | |
657 | struct vm_area_struct *vma; | |
8feae131 | 658 | unsigned long end = addr + len; |
47d9644d | 659 | VMA_ITERATOR(vmi, mm, addr); |
8feae131 | 660 | |
47d9644d | 661 | vma = vma_iter_load(&vmi); |
524e00b3 LH |
662 | if (!vma) |
663 | return NULL; | |
664 | if (vma->vm_start != addr) | |
665 | return NULL; | |
666 | if (vma->vm_end != end) | |
667 | return NULL; | |
668 | ||
524e00b3 | 669 | return vma; |
1da177e4 LT |
670 | } |
671 | ||
672 | /* | |
673 | * determine whether a mapping should be permitted and, if so, what sort of | |
674 | * mapping we're capable of supporting | |
675 | */ | |
676 | static int validate_mmap_request(struct file *file, | |
677 | unsigned long addr, | |
678 | unsigned long len, | |
679 | unsigned long prot, | |
680 | unsigned long flags, | |
681 | unsigned long pgoff, | |
682 | unsigned long *_capabilities) | |
683 | { | |
8feae131 | 684 | unsigned long capabilities, rlen; |
1da177e4 LT |
685 | int ret; |
686 | ||
687 | /* do the simple checks first */ | |
22cc877b | 688 | if (flags & MAP_FIXED) |
1da177e4 | 689 | return -EINVAL; |
1da177e4 LT |
690 | |
691 | if ((flags & MAP_TYPE) != MAP_PRIVATE && | |
692 | (flags & MAP_TYPE) != MAP_SHARED) | |
693 | return -EINVAL; | |
694 | ||
f81cff0d | 695 | if (!len) |
1da177e4 LT |
696 | return -EINVAL; |
697 | ||
f81cff0d | 698 | /* Careful about overflows.. */ |
8feae131 DH |
699 | rlen = PAGE_ALIGN(len); |
700 | if (!rlen || rlen > TASK_SIZE) | |
f81cff0d MF |
701 | return -ENOMEM; |
702 | ||
1da177e4 | 703 | /* offset overflow? */ |
8feae131 | 704 | if ((pgoff + (rlen >> PAGE_SHIFT)) < pgoff) |
f81cff0d | 705 | return -EOVERFLOW; |
1da177e4 LT |
706 | |
707 | if (file) { | |
1da177e4 | 708 | /* files must support mmap */ |
72c2d531 | 709 | if (!file->f_op->mmap) |
1da177e4 LT |
710 | return -ENODEV; |
711 | ||
712 | /* work out if what we've got could possibly be shared | |
713 | * - we support chardevs that provide their own "memory" | |
714 | * - we support files/blockdevs that are memory backed | |
715 | */ | |
b4caecd4 CH |
716 | if (file->f_op->mmap_capabilities) { |
717 | capabilities = file->f_op->mmap_capabilities(file); | |
718 | } else { | |
1da177e4 LT |
719 | /* no explicit capabilities set, so assume some |
720 | * defaults */ | |
496ad9aa | 721 | switch (file_inode(file)->i_mode & S_IFMT) { |
1da177e4 LT |
722 | case S_IFREG: |
723 | case S_IFBLK: | |
b4caecd4 | 724 | capabilities = NOMMU_MAP_COPY; |
1da177e4 LT |
725 | break; |
726 | ||
727 | case S_IFCHR: | |
728 | capabilities = | |
b4caecd4 CH |
729 | NOMMU_MAP_DIRECT | |
730 | NOMMU_MAP_READ | | |
731 | NOMMU_MAP_WRITE; | |
1da177e4 LT |
732 | break; |
733 | ||
734 | default: | |
735 | return -EINVAL; | |
736 | } | |
737 | } | |
738 | ||
739 | /* eliminate any capabilities that we can't support on this | |
740 | * device */ | |
741 | if (!file->f_op->get_unmapped_area) | |
b4caecd4 | 742 | capabilities &= ~NOMMU_MAP_DIRECT; |
6e242a1c | 743 | if (!(file->f_mode & FMODE_CAN_READ)) |
b4caecd4 | 744 | capabilities &= ~NOMMU_MAP_COPY; |
1da177e4 | 745 | |
28d7a6ae GY |
746 | /* The file shall have been opened with read permission. */ |
747 | if (!(file->f_mode & FMODE_READ)) | |
748 | return -EACCES; | |
749 | ||
1da177e4 LT |
750 | if (flags & MAP_SHARED) { |
751 | /* do checks for writing, appending and locking */ | |
752 | if ((prot & PROT_WRITE) && | |
753 | !(file->f_mode & FMODE_WRITE)) | |
754 | return -EACCES; | |
755 | ||
496ad9aa | 756 | if (IS_APPEND(file_inode(file)) && |
1da177e4 LT |
757 | (file->f_mode & FMODE_WRITE)) |
758 | return -EACCES; | |
759 | ||
b4caecd4 | 760 | if (!(capabilities & NOMMU_MAP_DIRECT)) |
1da177e4 LT |
761 | return -ENODEV; |
762 | ||
1da177e4 | 763 | /* we mustn't privatise shared mappings */ |
b4caecd4 | 764 | capabilities &= ~NOMMU_MAP_COPY; |
ac714904 | 765 | } else { |
1da177e4 LT |
766 | /* we're going to read the file into private memory we |
767 | * allocate */ | |
b4caecd4 | 768 | if (!(capabilities & NOMMU_MAP_COPY)) |
1da177e4 LT |
769 | return -ENODEV; |
770 | ||
771 | /* we don't permit a private writable mapping to be | |
772 | * shared with the backing device */ | |
773 | if (prot & PROT_WRITE) | |
b4caecd4 | 774 | capabilities &= ~NOMMU_MAP_DIRECT; |
1da177e4 LT |
775 | } |
776 | ||
b4caecd4 CH |
777 | if (capabilities & NOMMU_MAP_DIRECT) { |
778 | if (((prot & PROT_READ) && !(capabilities & NOMMU_MAP_READ)) || | |
779 | ((prot & PROT_WRITE) && !(capabilities & NOMMU_MAP_WRITE)) || | |
780 | ((prot & PROT_EXEC) && !(capabilities & NOMMU_MAP_EXEC)) | |
3c7b2045 | 781 | ) { |
b4caecd4 | 782 | capabilities &= ~NOMMU_MAP_DIRECT; |
3c7b2045 | 783 | if (flags & MAP_SHARED) { |
22cc877b | 784 | pr_warn("MAP_SHARED not completely supported on !MMU\n"); |
3c7b2045 BS |
785 | return -EINVAL; |
786 | } | |
787 | } | |
788 | } | |
789 | ||
1da177e4 LT |
790 | /* handle executable mappings and implied executable |
791 | * mappings */ | |
90f8572b | 792 | if (path_noexec(&file->f_path)) { |
1da177e4 LT |
793 | if (prot & PROT_EXEC) |
794 | return -EPERM; | |
ac714904 | 795 | } else if ((prot & PROT_READ) && !(prot & PROT_EXEC)) { |
1da177e4 LT |
796 | /* handle implication of PROT_EXEC by PROT_READ */ |
797 | if (current->personality & READ_IMPLIES_EXEC) { | |
b4caecd4 | 798 | if (capabilities & NOMMU_MAP_EXEC) |
1da177e4 LT |
799 | prot |= PROT_EXEC; |
800 | } | |
ac714904 | 801 | } else if ((prot & PROT_READ) && |
1da177e4 | 802 | (prot & PROT_EXEC) && |
b4caecd4 | 803 | !(capabilities & NOMMU_MAP_EXEC) |
1da177e4 LT |
804 | ) { |
805 | /* backing file is not executable, try to copy */ | |
b4caecd4 | 806 | capabilities &= ~NOMMU_MAP_DIRECT; |
1da177e4 | 807 | } |
ac714904 | 808 | } else { |
1da177e4 LT |
809 | /* anonymous mappings are always memory backed and can be |
810 | * privately mapped | |
811 | */ | |
b4caecd4 | 812 | capabilities = NOMMU_MAP_COPY; |
1da177e4 LT |
813 | |
814 | /* handle PROT_EXEC implication by PROT_READ */ | |
815 | if ((prot & PROT_READ) && | |
816 | (current->personality & READ_IMPLIES_EXEC)) | |
817 | prot |= PROT_EXEC; | |
818 | } | |
819 | ||
820 | /* allow the security API to have its say */ | |
e5467859 | 821 | ret = security_mmap_addr(addr); |
1da177e4 LT |
822 | if (ret < 0) |
823 | return ret; | |
824 | ||
825 | /* looks okay */ | |
826 | *_capabilities = capabilities; | |
827 | return 0; | |
828 | } | |
829 | ||
830 | /* | |
831 | * we've determined that we can make the mapping, now translate what we | |
832 | * now know into VMA flags | |
833 | */ | |
834 | static unsigned long determine_vm_flags(struct file *file, | |
835 | unsigned long prot, | |
836 | unsigned long flags, | |
837 | unsigned long capabilities) | |
838 | { | |
839 | unsigned long vm_flags; | |
840 | ||
e6bfb709 | 841 | vm_flags = calc_vm_prot_bits(prot, 0) | calc_vm_flag_bits(flags); |
1da177e4 | 842 | |
b6b7a8fa DH |
843 | if (!file) { |
844 | /* | |
845 | * MAP_ANONYMOUS. MAP_SHARED is mapped to MAP_PRIVATE, because | |
846 | * there is no fork(). | |
847 | */ | |
3c7b2045 | 848 | vm_flags |= VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC; |
b6b7a8fa DH |
849 | } else if (flags & MAP_PRIVATE) { |
850 | /* MAP_PRIVATE file mapping */ | |
851 | if (capabilities & NOMMU_MAP_DIRECT) | |
852 | vm_flags |= (capabilities & NOMMU_VMFLAGS); | |
853 | else | |
854 | vm_flags |= VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC; | |
855 | ||
856 | if (!(prot & PROT_WRITE) && !current->ptrace) | |
857 | /* | |
858 | * R/O private file mapping which cannot be used to | |
859 | * modify memory, especially also not via active ptrace | |
860 | * (e.g., set breakpoints) or later by upgrading | |
861 | * permissions (no mprotect()). We can try overlaying | |
862 | * the file mapping, which will work e.g., on chardevs, | |
863 | * ramfs/tmpfs/shmfs and romfs/cramf. | |
864 | */ | |
865 | vm_flags |= VM_MAYOVERLAY; | |
3c7b2045 | 866 | } else { |
b6b7a8fa DH |
867 | /* MAP_SHARED file mapping: NOMMU_MAP_DIRECT is set. */ |
868 | vm_flags |= VM_SHARED | VM_MAYSHARE | | |
869 | (capabilities & NOMMU_VMFLAGS); | |
1da177e4 LT |
870 | } |
871 | ||
1da177e4 LT |
872 | return vm_flags; |
873 | } | |
874 | ||
875 | /* | |
8feae131 DH |
876 | * set up a shared mapping on a file (the driver or filesystem provides and |
877 | * pins the storage) | |
1da177e4 | 878 | */ |
8feae131 | 879 | static int do_mmap_shared_file(struct vm_area_struct *vma) |
1da177e4 LT |
880 | { |
881 | int ret; | |
882 | ||
f74ac015 | 883 | ret = call_mmap(vma->vm_file, vma); |
dd8632a1 PM |
884 | if (ret == 0) { |
885 | vma->vm_region->vm_top = vma->vm_region->vm_end; | |
645d83c5 | 886 | return 0; |
dd8632a1 | 887 | } |
1da177e4 LT |
888 | if (ret != -ENOSYS) |
889 | return ret; | |
890 | ||
3fa30460 DH |
891 | /* getting -ENOSYS indicates that direct mmap isn't possible (as |
892 | * opposed to tried but failed) so we can only give a suitable error as | |
893 | * it's not possible to make a private copy if MAP_SHARED was given */ | |
1da177e4 LT |
894 | return -ENODEV; |
895 | } | |
896 | ||
897 | /* | |
898 | * set up a private mapping or an anonymous shared mapping | |
899 | */ | |
8feae131 DH |
900 | static int do_mmap_private(struct vm_area_struct *vma, |
901 | struct vm_region *region, | |
645d83c5 DH |
902 | unsigned long len, |
903 | unsigned long capabilities) | |
1da177e4 | 904 | { |
dbc8358c | 905 | unsigned long total, point; |
1da177e4 | 906 | void *base; |
8feae131 | 907 | int ret, order; |
1da177e4 | 908 | |
b6b7a8fa DH |
909 | /* |
910 | * Invoke the file's mapping function so that it can keep track of | |
911 | * shared mappings on devices or memory. VM_MAYOVERLAY will be set if | |
912 | * it may attempt to share, which will make is_nommu_shared_mapping() | |
913 | * happy. | |
1da177e4 | 914 | */ |
b4caecd4 | 915 | if (capabilities & NOMMU_MAP_DIRECT) { |
f74ac015 | 916 | ret = call_mmap(vma->vm_file, vma); |
fc4f4be9 DH |
917 | /* shouldn't return success if we're not sharing */ |
918 | if (WARN_ON_ONCE(!is_nommu_shared_mapping(vma->vm_flags))) | |
919 | ret = -ENOSYS; | |
dd8632a1 | 920 | if (ret == 0) { |
dd8632a1 | 921 | vma->vm_region->vm_top = vma->vm_region->vm_end; |
645d83c5 | 922 | return 0; |
1da177e4 | 923 | } |
dd8632a1 PM |
924 | if (ret != -ENOSYS) |
925 | return ret; | |
1da177e4 LT |
926 | |
927 | /* getting an ENOSYS error indicates that direct mmap isn't | |
928 | * possible (as opposed to tried but failed) so we'll try to | |
929 | * make a private copy of the data and map that instead */ | |
930 | } | |
931 | ||
8feae131 | 932 | |
1da177e4 LT |
933 | /* allocate some memory to hold the mapping |
934 | * - note that this may not return a page-aligned address if the object | |
935 | * we're allocating is smaller than a page | |
936 | */ | |
f67d9b15 | 937 | order = get_order(len); |
8feae131 | 938 | total = 1 << order; |
f67d9b15 | 939 | point = len >> PAGE_SHIFT; |
dd8632a1 | 940 | |
dbc8358c | 941 | /* we don't want to allocate a power-of-2 sized page set */ |
22cc877b | 942 | if (sysctl_nr_trim_pages && total - point >= sysctl_nr_trim_pages) |
dbc8358c | 943 | total = point; |
8feae131 | 944 | |
da616534 | 945 | base = alloc_pages_exact(total << PAGE_SHIFT, GFP_KERNEL); |
dbc8358c JK |
946 | if (!base) |
947 | goto enomem; | |
948 | ||
949 | atomic_long_add(total, &mmap_pages_allocated); | |
1da177e4 | 950 | |
1c71222e SB |
951 | vm_flags_set(vma, VM_MAPPED_COPY); |
952 | region->vm_flags = vma->vm_flags; | |
8feae131 | 953 | region->vm_start = (unsigned long) base; |
f67d9b15 | 954 | region->vm_end = region->vm_start + len; |
dd8632a1 | 955 | region->vm_top = region->vm_start + (total << PAGE_SHIFT); |
8feae131 DH |
956 | |
957 | vma->vm_start = region->vm_start; | |
958 | vma->vm_end = region->vm_start + len; | |
1da177e4 LT |
959 | |
960 | if (vma->vm_file) { | |
961 | /* read the contents of a file into the copy */ | |
1da177e4 LT |
962 | loff_t fpos; |
963 | ||
964 | fpos = vma->vm_pgoff; | |
965 | fpos <<= PAGE_SHIFT; | |
966 | ||
b4bf802a | 967 | ret = kernel_read(vma->vm_file, base, len, &fpos); |
1da177e4 LT |
968 | if (ret < 0) |
969 | goto error_free; | |
970 | ||
971 | /* clear the last little bit */ | |
f67d9b15 BL |
972 | if (ret < len) |
973 | memset(base + ret, 0, len - ret); | |
1da177e4 | 974 | |
bfd40eaf KS |
975 | } else { |
976 | vma_set_anonymous(vma); | |
1da177e4 LT |
977 | } |
978 | ||
979 | return 0; | |
980 | ||
981 | error_free: | |
7223bb4a | 982 | free_page_series(region->vm_start, region->vm_top); |
8feae131 DH |
983 | region->vm_start = vma->vm_start = 0; |
984 | region->vm_end = vma->vm_end = 0; | |
dd8632a1 | 985 | region->vm_top = 0; |
1da177e4 LT |
986 | return ret; |
987 | ||
988 | enomem: | |
b1de0d13 | 989 | pr_err("Allocation of length %lu from process %d (%s) failed\n", |
05ae6fa3 | 990 | len, current->pid, current->comm); |
1279aa06 | 991 | show_mem(); |
1da177e4 LT |
992 | return -ENOMEM; |
993 | } | |
994 | ||
995 | /* | |
996 | * handle mapping creation for uClinux | |
997 | */ | |
1fcfd8db ON |
998 | unsigned long do_mmap(struct file *file, |
999 | unsigned long addr, | |
1000 | unsigned long len, | |
1001 | unsigned long prot, | |
1002 | unsigned long flags, | |
592b5fad | 1003 | vm_flags_t vm_flags, |
1fcfd8db | 1004 | unsigned long pgoff, |
897ab3e0 MR |
1005 | unsigned long *populate, |
1006 | struct list_head *uf) | |
1da177e4 | 1007 | { |
8feae131 DH |
1008 | struct vm_area_struct *vma; |
1009 | struct vm_region *region; | |
1da177e4 | 1010 | struct rb_node *rb; |
1fcfd8db | 1011 | unsigned long capabilities, result; |
1da177e4 | 1012 | int ret; |
47d9644d | 1013 | VMA_ITERATOR(vmi, current->mm, 0); |
1da177e4 | 1014 | |
41badc15 | 1015 | *populate = 0; |
bebeb3d6 | 1016 | |
1da177e4 LT |
1017 | /* decide whether we should attempt the mapping, and if so what sort of |
1018 | * mapping */ | |
1019 | ret = validate_mmap_request(file, addr, len, prot, flags, pgoff, | |
1020 | &capabilities); | |
22cc877b | 1021 | if (ret < 0) |
1da177e4 LT |
1022 | return ret; |
1023 | ||
06aab5a3 DH |
1024 | /* we ignore the address hint */ |
1025 | addr = 0; | |
f67d9b15 | 1026 | len = PAGE_ALIGN(len); |
06aab5a3 | 1027 | |
1da177e4 LT |
1028 | /* we've determined that we can make the mapping, now translate what we |
1029 | * now know into VMA flags */ | |
592b5fad | 1030 | vm_flags |= determine_vm_flags(file, prot, flags, capabilities); |
1da177e4 | 1031 | |
8220543d | 1032 | |
8feae131 DH |
1033 | /* we're going to need to record the mapping */ |
1034 | region = kmem_cache_zalloc(vm_region_jar, GFP_KERNEL); | |
1035 | if (!region) | |
1036 | goto error_getting_region; | |
1037 | ||
490fc053 | 1038 | vma = vm_area_alloc(current->mm); |
8feae131 DH |
1039 | if (!vma) |
1040 | goto error_getting_vma; | |
1da177e4 | 1041 | |
1e2ae599 | 1042 | region->vm_usage = 1; |
8feae131 DH |
1043 | region->vm_flags = vm_flags; |
1044 | region->vm_pgoff = pgoff; | |
1045 | ||
1c71222e | 1046 | vm_flags_init(vma, vm_flags); |
8feae131 | 1047 | vma->vm_pgoff = pgoff; |
1da177e4 | 1048 | |
8feae131 | 1049 | if (file) { |
cb0942b8 AV |
1050 | region->vm_file = get_file(file); |
1051 | vma->vm_file = get_file(file); | |
8feae131 DH |
1052 | } |
1053 | ||
1054 | down_write(&nommu_region_sem); | |
1055 | ||
1056 | /* if we want to share, we need to check for regions created by other | |
1da177e4 | 1057 | * mmap() calls that overlap with our proposed mapping |
8feae131 | 1058 | * - we can only share with a superset match on most regular files |
1da177e4 LT |
1059 | * - shared mappings on character devices and memory backed files are |
1060 | * permitted to overlap inexactly as far as we are concerned for in | |
1061 | * these cases, sharing is handled in the driver or filesystem rather | |
1062 | * than here | |
1063 | */ | |
fc4f4be9 | 1064 | if (is_nommu_shared_mapping(vm_flags)) { |
8feae131 DH |
1065 | struct vm_region *pregion; |
1066 | unsigned long pglen, rpglen, pgend, rpgend, start; | |
1da177e4 | 1067 | |
8feae131 DH |
1068 | pglen = (len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
1069 | pgend = pgoff + pglen; | |
165b2392 | 1070 | |
8feae131 DH |
1071 | for (rb = rb_first(&nommu_region_tree); rb; rb = rb_next(rb)) { |
1072 | pregion = rb_entry(rb, struct vm_region, vm_rb); | |
1da177e4 | 1073 | |
fc4f4be9 | 1074 | if (!is_nommu_shared_mapping(pregion->vm_flags)) |
1da177e4 LT |
1075 | continue; |
1076 | ||
1077 | /* search for overlapping mappings on the same file */ | |
496ad9aa AV |
1078 | if (file_inode(pregion->vm_file) != |
1079 | file_inode(file)) | |
1da177e4 LT |
1080 | continue; |
1081 | ||
8feae131 | 1082 | if (pregion->vm_pgoff >= pgend) |
1da177e4 LT |
1083 | continue; |
1084 | ||
8feae131 DH |
1085 | rpglen = pregion->vm_end - pregion->vm_start; |
1086 | rpglen = (rpglen + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
1087 | rpgend = pregion->vm_pgoff + rpglen; | |
1088 | if (pgoff >= rpgend) | |
1da177e4 LT |
1089 | continue; |
1090 | ||
8feae131 DH |
1091 | /* handle inexactly overlapping matches between |
1092 | * mappings */ | |
1093 | if ((pregion->vm_pgoff != pgoff || rpglen != pglen) && | |
1094 | !(pgoff >= pregion->vm_pgoff && pgend <= rpgend)) { | |
1095 | /* new mapping is not a subset of the region */ | |
b4caecd4 | 1096 | if (!(capabilities & NOMMU_MAP_DIRECT)) |
1da177e4 LT |
1097 | goto sharing_violation; |
1098 | continue; | |
1099 | } | |
1100 | ||
8feae131 | 1101 | /* we've found a region we can share */ |
1e2ae599 | 1102 | pregion->vm_usage++; |
8feae131 DH |
1103 | vma->vm_region = pregion; |
1104 | start = pregion->vm_start; | |
1105 | start += (pgoff - pregion->vm_pgoff) << PAGE_SHIFT; | |
1106 | vma->vm_start = start; | |
1107 | vma->vm_end = start + len; | |
1108 | ||
22cc877b | 1109 | if (pregion->vm_flags & VM_MAPPED_COPY) |
1c71222e | 1110 | vm_flags_set(vma, VM_MAPPED_COPY); |
22cc877b | 1111 | else { |
8feae131 DH |
1112 | ret = do_mmap_shared_file(vma); |
1113 | if (ret < 0) { | |
1114 | vma->vm_region = NULL; | |
1115 | vma->vm_start = 0; | |
1116 | vma->vm_end = 0; | |
1e2ae599 | 1117 | pregion->vm_usage--; |
8feae131 DH |
1118 | pregion = NULL; |
1119 | goto error_just_free; | |
1120 | } | |
1121 | } | |
1122 | fput(region->vm_file); | |
1123 | kmem_cache_free(vm_region_jar, region); | |
1124 | region = pregion; | |
1125 | result = start; | |
1126 | goto share; | |
1da177e4 LT |
1127 | } |
1128 | ||
1da177e4 LT |
1129 | /* obtain the address at which to make a shared mapping |
1130 | * - this is the hook for quasi-memory character devices to | |
1131 | * tell us the location of a shared mapping | |
1132 | */ | |
b4caecd4 | 1133 | if (capabilities & NOMMU_MAP_DIRECT) { |
1da177e4 LT |
1134 | addr = file->f_op->get_unmapped_area(file, addr, len, |
1135 | pgoff, flags); | |
bb005a59 | 1136 | if (IS_ERR_VALUE(addr)) { |
1da177e4 | 1137 | ret = addr; |
bb005a59 | 1138 | if (ret != -ENOSYS) |
8feae131 | 1139 | goto error_just_free; |
1da177e4 LT |
1140 | |
1141 | /* the driver refused to tell us where to site | |
1142 | * the mapping so we'll have to attempt to copy | |
1143 | * it */ | |
bb005a59 | 1144 | ret = -ENODEV; |
b4caecd4 | 1145 | if (!(capabilities & NOMMU_MAP_COPY)) |
8feae131 | 1146 | goto error_just_free; |
1da177e4 | 1147 | |
b4caecd4 | 1148 | capabilities &= ~NOMMU_MAP_DIRECT; |
8feae131 DH |
1149 | } else { |
1150 | vma->vm_start = region->vm_start = addr; | |
1151 | vma->vm_end = region->vm_end = addr + len; | |
1da177e4 LT |
1152 | } |
1153 | } | |
1154 | } | |
1155 | ||
8feae131 | 1156 | vma->vm_region = region; |
1da177e4 | 1157 | |
645d83c5 | 1158 | /* set up the mapping |
b4caecd4 | 1159 | * - the region is filled in if NOMMU_MAP_DIRECT is still set |
645d83c5 | 1160 | */ |
1da177e4 | 1161 | if (file && vma->vm_flags & VM_SHARED) |
8feae131 | 1162 | ret = do_mmap_shared_file(vma); |
1da177e4 | 1163 | else |
645d83c5 | 1164 | ret = do_mmap_private(vma, region, len, capabilities); |
1da177e4 | 1165 | if (ret < 0) |
645d83c5 DH |
1166 | goto error_just_free; |
1167 | add_nommu_region(region); | |
8feae131 | 1168 | |
ea637639 | 1169 | /* clear anonymous mappings that don't ask for uninitialized data */ |
0bf5f949 CH |
1170 | if (!vma->vm_file && |
1171 | (!IS_ENABLED(CONFIG_MMAP_ALLOW_UNINITIALIZED) || | |
1172 | !(flags & MAP_UNINITIALIZED))) | |
ea637639 JZ |
1173 | memset((void *)region->vm_start, 0, |
1174 | region->vm_end - region->vm_start); | |
1175 | ||
1da177e4 | 1176 | /* okay... we have a mapping; now we have to register it */ |
8feae131 | 1177 | result = vma->vm_start; |
1da177e4 | 1178 | |
1da177e4 LT |
1179 | current->mm->total_vm += len >> PAGE_SHIFT; |
1180 | ||
8feae131 | 1181 | share: |
07f1bc5a | 1182 | BUG_ON(!vma->vm_region); |
b5df0922 LH |
1183 | vma_iter_config(&vmi, vma->vm_start, vma->vm_end); |
1184 | if (vma_iter_prealloc(&vmi, vma)) | |
1185 | goto error_just_free; | |
1186 | ||
07f1bc5a LH |
1187 | setup_vma_to_mm(vma, current->mm); |
1188 | current->mm->map_count++; | |
1189 | /* add the VMA to the tree */ | |
1190 | vma_iter_store(&vmi, vma); | |
1da177e4 | 1191 | |
cfe79c00 MF |
1192 | /* we flush the region from the icache only when the first executable |
1193 | * mapping of it is made */ | |
1194 | if (vma->vm_flags & VM_EXEC && !region->vm_icache_flushed) { | |
a75a2df6 | 1195 | flush_icache_user_range(region->vm_start, region->vm_end); |
cfe79c00 MF |
1196 | region->vm_icache_flushed = true; |
1197 | } | |
1da177e4 | 1198 | |
cfe79c00 | 1199 | up_write(&nommu_region_sem); |
1da177e4 | 1200 | |
8feae131 | 1201 | return result; |
1da177e4 | 1202 | |
8feae131 DH |
1203 | error_just_free: |
1204 | up_write(&nommu_region_sem); | |
1205 | error: | |
47d9644d | 1206 | vma_iter_free(&vmi); |
89a86402 DH |
1207 | if (region->vm_file) |
1208 | fput(region->vm_file); | |
8feae131 | 1209 | kmem_cache_free(vm_region_jar, region); |
89a86402 DH |
1210 | if (vma->vm_file) |
1211 | fput(vma->vm_file); | |
3928d4f5 | 1212 | vm_area_free(vma); |
8feae131 DH |
1213 | return ret; |
1214 | ||
1215 | sharing_violation: | |
1216 | up_write(&nommu_region_sem); | |
22cc877b | 1217 | pr_warn("Attempt to share mismatched mappings\n"); |
8feae131 DH |
1218 | ret = -EINVAL; |
1219 | goto error; | |
1da177e4 | 1220 | |
8feae131 DH |
1221 | error_getting_vma: |
1222 | kmem_cache_free(vm_region_jar, region); | |
22cc877b LR |
1223 | pr_warn("Allocation of vma for %lu byte allocation from process %d failed\n", |
1224 | len, current->pid); | |
1279aa06 | 1225 | show_mem(); |
1da177e4 LT |
1226 | return -ENOMEM; |
1227 | ||
8feae131 | 1228 | error_getting_region: |
22cc877b LR |
1229 | pr_warn("Allocation of vm region for %lu byte allocation from process %d failed\n", |
1230 | len, current->pid); | |
1279aa06 | 1231 | show_mem(); |
1da177e4 LT |
1232 | return -ENOMEM; |
1233 | } | |
6be5ceb0 | 1234 | |
a90f590a DB |
1235 | unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len, |
1236 | unsigned long prot, unsigned long flags, | |
1237 | unsigned long fd, unsigned long pgoff) | |
66f0dc48 HD |
1238 | { |
1239 | struct file *file = NULL; | |
1240 | unsigned long retval = -EBADF; | |
1241 | ||
120a795d | 1242 | audit_mmap_fd(fd, flags); |
66f0dc48 HD |
1243 | if (!(flags & MAP_ANONYMOUS)) { |
1244 | file = fget(fd); | |
1245 | if (!file) | |
1246 | goto out; | |
1247 | } | |
1248 | ||
ad1ed293 | 1249 | retval = vm_mmap_pgoff(file, addr, len, prot, flags, pgoff); |
66f0dc48 HD |
1250 | |
1251 | if (file) | |
1252 | fput(file); | |
1253 | out: | |
1254 | return retval; | |
1255 | } | |
1256 | ||
a90f590a DB |
1257 | SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len, |
1258 | unsigned long, prot, unsigned long, flags, | |
1259 | unsigned long, fd, unsigned long, pgoff) | |
1260 | { | |
1261 | return ksys_mmap_pgoff(addr, len, prot, flags, fd, pgoff); | |
1262 | } | |
1263 | ||
a4679373 CH |
1264 | #ifdef __ARCH_WANT_SYS_OLD_MMAP |
1265 | struct mmap_arg_struct { | |
1266 | unsigned long addr; | |
1267 | unsigned long len; | |
1268 | unsigned long prot; | |
1269 | unsigned long flags; | |
1270 | unsigned long fd; | |
1271 | unsigned long offset; | |
1272 | }; | |
1273 | ||
1274 | SYSCALL_DEFINE1(old_mmap, struct mmap_arg_struct __user *, arg) | |
1275 | { | |
1276 | struct mmap_arg_struct a; | |
1277 | ||
1278 | if (copy_from_user(&a, arg, sizeof(a))) | |
1279 | return -EFAULT; | |
1824cb75 | 1280 | if (offset_in_page(a.offset)) |
a4679373 CH |
1281 | return -EINVAL; |
1282 | ||
a90f590a DB |
1283 | return ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, |
1284 | a.offset >> PAGE_SHIFT); | |
a4679373 CH |
1285 | } |
1286 | #endif /* __ARCH_WANT_SYS_OLD_MMAP */ | |
1287 | ||
1da177e4 | 1288 | /* |
8feae131 DH |
1289 | * split a vma into two pieces at address 'addr', a new vma is allocated either |
1290 | * for the first part or the tail. | |
1da177e4 | 1291 | */ |
adb20b0c LS |
1292 | static int split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma, |
1293 | unsigned long addr, int new_below) | |
1da177e4 | 1294 | { |
8feae131 DH |
1295 | struct vm_area_struct *new; |
1296 | struct vm_region *region; | |
1297 | unsigned long npages; | |
9760ebff | 1298 | struct mm_struct *mm; |
1da177e4 | 1299 | |
779c1023 DH |
1300 | /* we're only permitted to split anonymous regions (these should have |
1301 | * only a single usage on the region) */ | |
1302 | if (vma->vm_file) | |
8feae131 | 1303 | return -ENOMEM; |
1da177e4 | 1304 | |
9760ebff | 1305 | mm = vma->vm_mm; |
8feae131 DH |
1306 | if (mm->map_count >= sysctl_max_map_count) |
1307 | return -ENOMEM; | |
1da177e4 | 1308 | |
8feae131 DH |
1309 | region = kmem_cache_alloc(vm_region_jar, GFP_KERNEL); |
1310 | if (!region) | |
1311 | return -ENOMEM; | |
1da177e4 | 1312 | |
3928d4f5 | 1313 | new = vm_area_dup(vma); |
8220543d MWO |
1314 | if (!new) |
1315 | goto err_vma_dup; | |
1316 | ||
8feae131 | 1317 | /* most fields are the same, copy all, and then fixup */ |
8feae131 DH |
1318 | *region = *vma->vm_region; |
1319 | new->vm_region = region; | |
1320 | ||
1321 | npages = (addr - vma->vm_start) >> PAGE_SHIFT; | |
1322 | ||
1323 | if (new_below) { | |
dd8632a1 | 1324 | region->vm_top = region->vm_end = new->vm_end = addr; |
8feae131 DH |
1325 | } else { |
1326 | region->vm_start = new->vm_start = addr; | |
1327 | region->vm_pgoff = new->vm_pgoff += npages; | |
1da177e4 | 1328 | } |
8feae131 | 1329 | |
b5df0922 LH |
1330 | vma_iter_config(vmi, new->vm_start, new->vm_end); |
1331 | if (vma_iter_prealloc(vmi, vma)) { | |
1332 | pr_warn("Allocation of vma tree for process %d failed\n", | |
1333 | current->pid); | |
1334 | goto err_vmi_preallocate; | |
1335 | } | |
1336 | ||
8feae131 DH |
1337 | if (new->vm_ops && new->vm_ops->open) |
1338 | new->vm_ops->open(new); | |
1339 | ||
8feae131 DH |
1340 | down_write(&nommu_region_sem); |
1341 | delete_nommu_region(vma->vm_region); | |
1342 | if (new_below) { | |
1343 | vma->vm_region->vm_start = vma->vm_start = addr; | |
1344 | vma->vm_region->vm_pgoff = vma->vm_pgoff += npages; | |
1345 | } else { | |
1346 | vma->vm_region->vm_end = vma->vm_end = addr; | |
dd8632a1 | 1347 | vma->vm_region->vm_top = addr; |
8feae131 DH |
1348 | } |
1349 | add_nommu_region(vma->vm_region); | |
1350 | add_nommu_region(new->vm_region); | |
1351 | up_write(&nommu_region_sem); | |
8220543d MWO |
1352 | |
1353 | setup_vma_to_mm(vma, mm); | |
1354 | setup_vma_to_mm(new, mm); | |
47d9644d | 1355 | vma_iter_store(vmi, new); |
fd9edbdb | 1356 | mm->map_count++; |
8feae131 | 1357 | return 0; |
8220543d | 1358 | |
47d9644d | 1359 | err_vmi_preallocate: |
8220543d MWO |
1360 | vm_area_free(new); |
1361 | err_vma_dup: | |
1362 | kmem_cache_free(vm_region_jar, region); | |
1363 | return -ENOMEM; | |
1da177e4 LT |
1364 | } |
1365 | ||
3034097a | 1366 | /* |
8feae131 DH |
1367 | * shrink a VMA by removing the specified chunk from either the beginning or |
1368 | * the end | |
3034097a | 1369 | */ |
07f1bc5a | 1370 | static int vmi_shrink_vma(struct vma_iterator *vmi, |
8feae131 DH |
1371 | struct vm_area_struct *vma, |
1372 | unsigned long from, unsigned long to) | |
1da177e4 | 1373 | { |
8feae131 | 1374 | struct vm_region *region; |
1da177e4 | 1375 | |
8feae131 DH |
1376 | /* adjust the VMA's pointers, which may reposition it in the MM's tree |
1377 | * and list */ | |
07f1bc5a | 1378 | if (from > vma->vm_start) { |
f72cf24a LH |
1379 | if (vma_iter_clear_gfp(vmi, from, vma->vm_end, GFP_KERNEL)) |
1380 | return -ENOMEM; | |
8feae131 | 1381 | vma->vm_end = from; |
07f1bc5a | 1382 | } else { |
f72cf24a LH |
1383 | if (vma_iter_clear_gfp(vmi, vma->vm_start, to, GFP_KERNEL)) |
1384 | return -ENOMEM; | |
8feae131 | 1385 | vma->vm_start = to; |
07f1bc5a | 1386 | } |
1da177e4 | 1387 | |
8feae131 DH |
1388 | /* cut the backing region down to size */ |
1389 | region = vma->vm_region; | |
1e2ae599 | 1390 | BUG_ON(region->vm_usage != 1); |
8feae131 DH |
1391 | |
1392 | down_write(&nommu_region_sem); | |
1393 | delete_nommu_region(region); | |
dd8632a1 PM |
1394 | if (from > region->vm_start) { |
1395 | to = region->vm_top; | |
1396 | region->vm_top = region->vm_end = from; | |
1397 | } else { | |
8feae131 | 1398 | region->vm_start = to; |
dd8632a1 | 1399 | } |
8feae131 DH |
1400 | add_nommu_region(region); |
1401 | up_write(&nommu_region_sem); | |
1402 | ||
1403 | free_page_series(from, to); | |
1404 | return 0; | |
1405 | } | |
1da177e4 | 1406 | |
8feae131 DH |
1407 | /* |
1408 | * release a mapping | |
1409 | * - under NOMMU conditions the chunk to be unmapped must be backed by a single | |
1410 | * VMA, though it need not cover the whole VMA | |
1411 | */ | |
897ab3e0 | 1412 | int do_munmap(struct mm_struct *mm, unsigned long start, size_t len, struct list_head *uf) |
8feae131 | 1413 | { |
47d9644d | 1414 | VMA_ITERATOR(vmi, mm, start); |
8feae131 | 1415 | struct vm_area_struct *vma; |
f67d9b15 | 1416 | unsigned long end; |
8220543d | 1417 | int ret = 0; |
1da177e4 | 1418 | |
f67d9b15 | 1419 | len = PAGE_ALIGN(len); |
8feae131 DH |
1420 | if (len == 0) |
1421 | return -EINVAL; | |
365e9c87 | 1422 | |
f67d9b15 BL |
1423 | end = start + len; |
1424 | ||
8feae131 | 1425 | /* find the first potentially overlapping VMA */ |
47d9644d | 1426 | vma = vma_find(&vmi, end); |
8feae131 | 1427 | if (!vma) { |
ac714904 | 1428 | static int limit; |
33e5d769 | 1429 | if (limit < 5) { |
22cc877b LR |
1430 | pr_warn("munmap of memory not mmapped by process %d (%s): 0x%lx-0x%lx\n", |
1431 | current->pid, current->comm, | |
1432 | start, start + len - 1); | |
33e5d769 DH |
1433 | limit++; |
1434 | } | |
8feae131 DH |
1435 | return -EINVAL; |
1436 | } | |
1da177e4 | 1437 | |
8feae131 DH |
1438 | /* we're allowed to split an anonymous VMA but not a file-backed one */ |
1439 | if (vma->vm_file) { | |
1440 | do { | |
22cc877b | 1441 | if (start > vma->vm_start) |
8feae131 | 1442 | return -EINVAL; |
8feae131 DH |
1443 | if (end == vma->vm_end) |
1444 | goto erase_whole_vma; | |
47d9644d | 1445 | vma = vma_find(&vmi, end); |
d75a310c | 1446 | } while (vma); |
8feae131 DH |
1447 | return -EINVAL; |
1448 | } else { | |
1449 | /* the chunk must be a subset of the VMA found */ | |
1450 | if (start == vma->vm_start && end == vma->vm_end) | |
1451 | goto erase_whole_vma; | |
22cc877b | 1452 | if (start < vma->vm_start || end > vma->vm_end) |
8feae131 | 1453 | return -EINVAL; |
1824cb75 | 1454 | if (offset_in_page(start)) |
8feae131 | 1455 | return -EINVAL; |
1824cb75 | 1456 | if (end != vma->vm_end && offset_in_page(end)) |
8feae131 | 1457 | return -EINVAL; |
8feae131 | 1458 | if (start != vma->vm_start && end != vma->vm_end) { |
9760ebff | 1459 | ret = split_vma(&vmi, vma, start, 1); |
22cc877b | 1460 | if (ret < 0) |
8feae131 | 1461 | return ret; |
8feae131 | 1462 | } |
07f1bc5a | 1463 | return vmi_shrink_vma(&vmi, vma, start, end); |
8feae131 | 1464 | } |
1da177e4 | 1465 | |
8feae131 | 1466 | erase_whole_vma: |
8220543d MWO |
1467 | if (delete_vma_from_mm(vma)) |
1468 | ret = -ENOMEM; | |
80be727e LH |
1469 | else |
1470 | delete_vma(mm, vma); | |
8220543d | 1471 | return ret; |
1da177e4 LT |
1472 | } |
1473 | ||
bfce281c | 1474 | int vm_munmap(unsigned long addr, size_t len) |
3034097a | 1475 | { |
bfce281c | 1476 | struct mm_struct *mm = current->mm; |
3034097a | 1477 | int ret; |
3034097a | 1478 | |
d8ed45c5 | 1479 | mmap_write_lock(mm); |
897ab3e0 | 1480 | ret = do_munmap(mm, addr, len, NULL); |
d8ed45c5 | 1481 | mmap_write_unlock(mm); |
3034097a DH |
1482 | return ret; |
1483 | } | |
a46ef99d LT |
1484 | EXPORT_SYMBOL(vm_munmap); |
1485 | ||
1486 | SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len) | |
1487 | { | |
bfce281c | 1488 | return vm_munmap(addr, len); |
a46ef99d | 1489 | } |
3034097a DH |
1490 | |
1491 | /* | |
8feae131 | 1492 | * release all the mappings made in a process's VM space |
3034097a | 1493 | */ |
8feae131 | 1494 | void exit_mmap(struct mm_struct *mm) |
1da177e4 | 1495 | { |
8220543d | 1496 | VMA_ITERATOR(vmi, mm, 0); |
8feae131 | 1497 | struct vm_area_struct *vma; |
1da177e4 | 1498 | |
8feae131 DH |
1499 | if (!mm) |
1500 | return; | |
1da177e4 | 1501 | |
8feae131 | 1502 | mm->total_vm = 0; |
1da177e4 | 1503 | |
8220543d MWO |
1504 | /* |
1505 | * Lock the mm to avoid assert complaining even though this is the only | |
1506 | * user of the mm | |
1507 | */ | |
1508 | mmap_write_lock(mm); | |
1509 | for_each_vma(vmi, vma) { | |
1510 | cleanup_vma_from_mm(vma); | |
8feae131 | 1511 | delete_vma(mm, vma); |
04c34961 | 1512 | cond_resched(); |
1da177e4 | 1513 | } |
524e00b3 | 1514 | __mt_destroy(&mm->mm_mt); |
8220543d | 1515 | mmap_write_unlock(mm); |
1da177e4 LT |
1516 | } |
1517 | ||
1da177e4 | 1518 | /* |
6fa5f80b DH |
1519 | * expand (or shrink) an existing mapping, potentially moving it at the same |
1520 | * time (controlled by the MREMAP_MAYMOVE flag and available VM space) | |
1da177e4 | 1521 | * |
6fa5f80b | 1522 | * under NOMMU conditions, we only permit changing a mapping's size, and only |
8feae131 DH |
1523 | * as long as it stays within the region allocated by do_mmap_private() and the |
1524 | * block is not shareable | |
1da177e4 | 1525 | * |
6fa5f80b | 1526 | * MREMAP_FIXED is not supported under NOMMU conditions |
1da177e4 | 1527 | */ |
4b377bab | 1528 | static unsigned long do_mremap(unsigned long addr, |
1da177e4 LT |
1529 | unsigned long old_len, unsigned long new_len, |
1530 | unsigned long flags, unsigned long new_addr) | |
1531 | { | |
6fa5f80b | 1532 | struct vm_area_struct *vma; |
1da177e4 LT |
1533 | |
1534 | /* insanity checks first */ | |
f67d9b15 BL |
1535 | old_len = PAGE_ALIGN(old_len); |
1536 | new_len = PAGE_ALIGN(new_len); | |
8feae131 | 1537 | if (old_len == 0 || new_len == 0) |
1da177e4 LT |
1538 | return (unsigned long) -EINVAL; |
1539 | ||
1824cb75 | 1540 | if (offset_in_page(addr)) |
8feae131 DH |
1541 | return -EINVAL; |
1542 | ||
1da177e4 LT |
1543 | if (flags & MREMAP_FIXED && new_addr != addr) |
1544 | return (unsigned long) -EINVAL; | |
1545 | ||
8feae131 | 1546 | vma = find_vma_exact(current->mm, addr, old_len); |
6fa5f80b DH |
1547 | if (!vma) |
1548 | return (unsigned long) -EINVAL; | |
1da177e4 | 1549 | |
6fa5f80b | 1550 | if (vma->vm_end != vma->vm_start + old_len) |
1da177e4 LT |
1551 | return (unsigned long) -EFAULT; |
1552 | ||
fc4f4be9 | 1553 | if (is_nommu_shared_mapping(vma->vm_flags)) |
1da177e4 LT |
1554 | return (unsigned long) -EPERM; |
1555 | ||
8feae131 | 1556 | if (new_len > vma->vm_region->vm_end - vma->vm_region->vm_start) |
1da177e4 LT |
1557 | return (unsigned long) -ENOMEM; |
1558 | ||
1559 | /* all checks complete - do it */ | |
6fa5f80b | 1560 | vma->vm_end = vma->vm_start + new_len; |
6fa5f80b DH |
1561 | return vma->vm_start; |
1562 | } | |
1563 | ||
6a6160a7 HC |
1564 | SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, |
1565 | unsigned long, new_len, unsigned long, flags, | |
1566 | unsigned long, new_addr) | |
6fa5f80b DH |
1567 | { |
1568 | unsigned long ret; | |
1569 | ||
d8ed45c5 | 1570 | mmap_write_lock(current->mm); |
6fa5f80b | 1571 | ret = do_mremap(addr, old_len, new_len, flags, new_addr); |
d8ed45c5 | 1572 | mmap_write_unlock(current->mm); |
6fa5f80b | 1573 | return ret; |
1da177e4 LT |
1574 | } |
1575 | ||
df06b37f KB |
1576 | struct page *follow_page(struct vm_area_struct *vma, unsigned long address, |
1577 | unsigned int foll_flags) | |
1da177e4 LT |
1578 | { |
1579 | return NULL; | |
1580 | } | |
1581 | ||
8f3b1327 BL |
1582 | int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, |
1583 | unsigned long pfn, unsigned long size, pgprot_t prot) | |
1da177e4 | 1584 | { |
8f3b1327 BL |
1585 | if (addr != (pfn << PAGE_SHIFT)) |
1586 | return -EINVAL; | |
1587 | ||
1c71222e | 1588 | vm_flags_set(vma, VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP); |
66aa2b4b | 1589 | return 0; |
1da177e4 | 1590 | } |
22c4af40 | 1591 | EXPORT_SYMBOL(remap_pfn_range); |
1da177e4 | 1592 | |
3c0b9de6 LT |
1593 | int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len) |
1594 | { | |
1595 | unsigned long pfn = start >> PAGE_SHIFT; | |
1596 | unsigned long vm_len = vma->vm_end - vma->vm_start; | |
1597 | ||
1598 | pfn += vma->vm_pgoff; | |
1599 | return io_remap_pfn_range(vma, vma->vm_start, pfn, vm_len, vma->vm_page_prot); | |
1600 | } | |
1601 | EXPORT_SYMBOL(vm_iomap_memory); | |
1602 | ||
f905bc44 PM |
1603 | int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, |
1604 | unsigned long pgoff) | |
1605 | { | |
1606 | unsigned int size = vma->vm_end - vma->vm_start; | |
1607 | ||
1608 | if (!(vma->vm_flags & VM_USERMAP)) | |
1609 | return -EINVAL; | |
1610 | ||
1611 | vma->vm_start = (unsigned long)(addr + (pgoff << PAGE_SHIFT)); | |
1612 | vma->vm_end = vma->vm_start + size; | |
1613 | ||
1614 | return 0; | |
1615 | } | |
1616 | EXPORT_SYMBOL(remap_vmalloc_range); | |
1617 | ||
2bcd6454 | 1618 | vm_fault_t filemap_fault(struct vm_fault *vmf) |
b0e15190 DH |
1619 | { |
1620 | BUG(); | |
d0217ac0 | 1621 | return 0; |
b0e15190 | 1622 | } |
b5073173 | 1623 | EXPORT_SYMBOL(filemap_fault); |
0ec76a11 | 1624 | |
3f98a28c | 1625 | vm_fault_t filemap_map_pages(struct vm_fault *vmf, |
bae473a4 | 1626 | pgoff_t start_pgoff, pgoff_t end_pgoff) |
f1820361 KS |
1627 | { |
1628 | BUG(); | |
3f98a28c | 1629 | return 0; |
f1820361 KS |
1630 | } |
1631 | EXPORT_SYMBOL(filemap_map_pages); | |
1632 | ||
c43cfa42 LS |
1633 | static int __access_remote_vm(struct mm_struct *mm, unsigned long addr, |
1634 | void *buf, int len, unsigned int gup_flags) | |
0ec76a11 | 1635 | { |
0ec76a11 | 1636 | struct vm_area_struct *vma; |
442486ec | 1637 | int write = gup_flags & FOLL_WRITE; |
0ec76a11 | 1638 | |
d8ed45c5 | 1639 | if (mmap_read_lock_killable(mm)) |
1e426fe2 | 1640 | return 0; |
0ec76a11 DH |
1641 | |
1642 | /* the access must start within one of the target process's mappings */ | |
0159b141 DH |
1643 | vma = find_vma(mm, addr); |
1644 | if (vma) { | |
0ec76a11 DH |
1645 | /* don't overrun this mapping */ |
1646 | if (addr + len >= vma->vm_end) | |
1647 | len = vma->vm_end - addr; | |
1648 | ||
1649 | /* only read or write mappings where it is permitted */ | |
d00c7b99 | 1650 | if (write && vma->vm_flags & VM_MAYWRITE) |
7959722b JZ |
1651 | copy_to_user_page(vma, NULL, addr, |
1652 | (void *) addr, buf, len); | |
d00c7b99 | 1653 | else if (!write && vma->vm_flags & VM_MAYREAD) |
7959722b JZ |
1654 | copy_from_user_page(vma, NULL, addr, |
1655 | buf, (void *) addr, len); | |
0ec76a11 DH |
1656 | else |
1657 | len = 0; | |
1658 | } else { | |
1659 | len = 0; | |
1660 | } | |
1661 | ||
d8ed45c5 | 1662 | mmap_read_unlock(mm); |
f55f199b MF |
1663 | |
1664 | return len; | |
1665 | } | |
1666 | ||
1667 | /** | |
b7701a5f | 1668 | * access_remote_vm - access another process' address space |
f55f199b MF |
1669 | * @mm: the mm_struct of the target address space |
1670 | * @addr: start address to access | |
1671 | * @buf: source or destination buffer | |
1672 | * @len: number of bytes to transfer | |
6347e8d5 | 1673 | * @gup_flags: flags modifying lookup behaviour |
f55f199b MF |
1674 | * |
1675 | * The caller must hold a reference on @mm. | |
1676 | */ | |
1677 | int access_remote_vm(struct mm_struct *mm, unsigned long addr, | |
6347e8d5 | 1678 | void *buf, int len, unsigned int gup_flags) |
f55f199b | 1679 | { |
d3f5ffca | 1680 | return __access_remote_vm(mm, addr, buf, len, gup_flags); |
f55f199b MF |
1681 | } |
1682 | ||
1683 | /* | |
1684 | * Access another process' address space. | |
1685 | * - source/target buffer must be kernel space | |
1686 | */ | |
f307ab6d LS |
1687 | int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, |
1688 | unsigned int gup_flags) | |
f55f199b MF |
1689 | { |
1690 | struct mm_struct *mm; | |
1691 | ||
1692 | if (addr + len < addr) | |
1693 | return 0; | |
1694 | ||
1695 | mm = get_task_mm(tsk); | |
1696 | if (!mm) | |
1697 | return 0; | |
1698 | ||
d3f5ffca | 1699 | len = __access_remote_vm(mm, addr, buf, len, gup_flags); |
f55f199b | 1700 | |
0ec76a11 DH |
1701 | mmput(mm); |
1702 | return len; | |
1703 | } | |
fcd35857 | 1704 | EXPORT_SYMBOL_GPL(access_process_vm); |
7e660872 DH |
1705 | |
1706 | /** | |
1707 | * nommu_shrink_inode_mappings - Shrink the shared mappings on an inode | |
1708 | * @inode: The inode to check | |
1709 | * @size: The current filesize of the inode | |
1710 | * @newsize: The proposed filesize of the inode | |
1711 | * | |
1712 | * Check the shared mappings on an inode on behalf of a shrinking truncate to | |
c08b342c RD |
1713 | * make sure that any outstanding VMAs aren't broken and then shrink the |
1714 | * vm_regions that extend beyond so that do_mmap() doesn't | |
7e660872 DH |
1715 | * automatically grant mappings that are too large. |
1716 | */ | |
1717 | int nommu_shrink_inode_mappings(struct inode *inode, size_t size, | |
1718 | size_t newsize) | |
1719 | { | |
1720 | struct vm_area_struct *vma; | |
7e660872 DH |
1721 | struct vm_region *region; |
1722 | pgoff_t low, high; | |
1723 | size_t r_size, r_top; | |
1724 | ||
1725 | low = newsize >> PAGE_SHIFT; | |
1726 | high = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
1727 | ||
1728 | down_write(&nommu_region_sem); | |
1acf2e04 | 1729 | i_mmap_lock_read(inode->i_mapping); |
7e660872 DH |
1730 | |
1731 | /* search for VMAs that fall within the dead zone */ | |
6b2dbba8 | 1732 | vma_interval_tree_foreach(vma, &inode->i_mapping->i_mmap, low, high) { |
7e660872 DH |
1733 | /* found one - only interested if it's shared out of the page |
1734 | * cache */ | |
1735 | if (vma->vm_flags & VM_SHARED) { | |
1acf2e04 | 1736 | i_mmap_unlock_read(inode->i_mapping); |
7e660872 DH |
1737 | up_write(&nommu_region_sem); |
1738 | return -ETXTBSY; /* not quite true, but near enough */ | |
1739 | } | |
1740 | } | |
1741 | ||
1742 | /* reduce any regions that overlap the dead zone - if in existence, | |
1743 | * these will be pointed to by VMAs that don't overlap the dead zone | |
1744 | * | |
1745 | * we don't check for any regions that start beyond the EOF as there | |
1746 | * shouldn't be any | |
1747 | */ | |
1acf2e04 | 1748 | vma_interval_tree_foreach(vma, &inode->i_mapping->i_mmap, 0, ULONG_MAX) { |
7e660872 DH |
1749 | if (!(vma->vm_flags & VM_SHARED)) |
1750 | continue; | |
1751 | ||
1752 | region = vma->vm_region; | |
1753 | r_size = region->vm_top - region->vm_start; | |
1754 | r_top = (region->vm_pgoff << PAGE_SHIFT) + r_size; | |
1755 | ||
1756 | if (r_top > newsize) { | |
1757 | region->vm_top -= r_top - newsize; | |
1758 | if (region->vm_end > region->vm_top) | |
1759 | region->vm_end = region->vm_top; | |
1760 | } | |
1761 | } | |
1762 | ||
1acf2e04 | 1763 | i_mmap_unlock_read(inode->i_mapping); |
7e660872 DH |
1764 | up_write(&nommu_region_sem); |
1765 | return 0; | |
1766 | } | |
c9b1d098 AS |
1767 | |
1768 | /* | |
1769 | * Initialise sysctl_user_reserve_kbytes. | |
1770 | * | |
1771 | * This is intended to prevent a user from starting a single memory hogging | |
1772 | * process, such that they cannot recover (kill the hog) in OVERCOMMIT_NEVER | |
1773 | * mode. | |
1774 | * | |
1775 | * The default value is min(3% of free memory, 128MB) | |
1776 | * 128MB is enough to recover with sshd/login, bash, and top/kill. | |
1777 | */ | |
1778 | static int __meminit init_user_reserve(void) | |
1779 | { | |
1780 | unsigned long free_kbytes; | |
1781 | ||
d5a6474d | 1782 | free_kbytes = K(global_zone_page_state(NR_FREE_PAGES)); |
c9b1d098 AS |
1783 | |
1784 | sysctl_user_reserve_kbytes = min(free_kbytes / 32, 1UL << 17); | |
1785 | return 0; | |
1786 | } | |
a4bc6fc7 | 1787 | subsys_initcall(init_user_reserve); |
4eeab4f5 AS |
1788 | |
1789 | /* | |
1790 | * Initialise sysctl_admin_reserve_kbytes. | |
1791 | * | |
1792 | * The purpose of sysctl_admin_reserve_kbytes is to allow the sys admin | |
1793 | * to log in and kill a memory hogging process. | |
1794 | * | |
1795 | * Systems with more than 256MB will reserve 8MB, enough to recover | |
1796 | * with sshd, bash, and top in OVERCOMMIT_GUESS. Smaller systems will | |
1797 | * only reserve 3% of free pages by default. | |
1798 | */ | |
1799 | static int __meminit init_admin_reserve(void) | |
1800 | { | |
1801 | unsigned long free_kbytes; | |
1802 | ||
d5a6474d | 1803 | free_kbytes = K(global_zone_page_state(NR_FREE_PAGES)); |
4eeab4f5 AS |
1804 | |
1805 | sysctl_admin_reserve_kbytes = min(free_kbytes / 32, 1UL << 13); | |
1806 | return 0; | |
1807 | } | |
a4bc6fc7 | 1808 | subsys_initcall(init_admin_reserve); |