Commit | Line | Data |
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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 <dhowells@redhat.com> |
1da177e4 LT |
11 | * Copyright (c) 2000-2003 David McCullough <davidm@snapgear.com> |
12 | * Copyright (c) 2000-2001 D Jeff Dionne <jeff@uClinux.org> | |
13 | * Copyright (c) 2002 Greg Ungerer <gerg@snapgear.com> | |
29c185e5 | 14 | * Copyright (c) 2007-2010 Paul Mundt <lethal@linux-sh.org> |
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 | ||
dfc2f91a PM |
113 | /** |
114 | * follow_pfn - look up PFN at a user virtual address | |
115 | * @vma: memory mapping | |
116 | * @address: user virtual address | |
117 | * @pfn: location to store found PFN | |
118 | * | |
119 | * Only IO mappings and raw PFN mappings are allowed. | |
120 | * | |
121 | * Returns zero and the pfn at @pfn on success, -ve otherwise. | |
122 | */ | |
123 | int follow_pfn(struct vm_area_struct *vma, unsigned long address, | |
124 | unsigned long *pfn) | |
125 | { | |
126 | if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) | |
127 | return -EINVAL; | |
128 | ||
129 | *pfn = address >> PAGE_SHIFT; | |
130 | return 0; | |
131 | } | |
132 | EXPORT_SYMBOL(follow_pfn); | |
133 | ||
b3bdda02 | 134 | void vfree(const void *addr) |
1da177e4 LT |
135 | { |
136 | kfree(addr); | |
137 | } | |
b5073173 | 138 | EXPORT_SYMBOL(vfree); |
1da177e4 | 139 | |
88dca4ca | 140 | void *__vmalloc(unsigned long size, gfp_t gfp_mask) |
1da177e4 LT |
141 | { |
142 | /* | |
8518609d RD |
143 | * You can't specify __GFP_HIGHMEM with kmalloc() since kmalloc() |
144 | * returns only a logical address. | |
1da177e4 | 145 | */ |
84097518 | 146 | return kmalloc(size, (gfp_mask | __GFP_COMP) & ~__GFP_HIGHMEM); |
1da177e4 | 147 | } |
b5073173 | 148 | EXPORT_SYMBOL(__vmalloc); |
1da177e4 | 149 | |
041de93f CH |
150 | void *__vmalloc_node_range(unsigned long size, unsigned long align, |
151 | unsigned long start, unsigned long end, gfp_t gfp_mask, | |
152 | pgprot_t prot, unsigned long vm_flags, int node, | |
153 | const void *caller) | |
154 | { | |
155 | return __vmalloc(size, gfp_mask); | |
156 | } | |
157 | ||
2b905948 CH |
158 | void *__vmalloc_node(unsigned long size, unsigned long align, gfp_t gfp_mask, |
159 | int node, const void *caller) | |
a7c3e901 | 160 | { |
2b905948 | 161 | return __vmalloc(size, gfp_mask); |
a7c3e901 MH |
162 | } |
163 | ||
ed81745a | 164 | static void *__vmalloc_user_flags(unsigned long size, gfp_t flags) |
f905bc44 PM |
165 | { |
166 | void *ret; | |
167 | ||
88dca4ca | 168 | ret = __vmalloc(size, flags); |
f905bc44 PM |
169 | if (ret) { |
170 | struct vm_area_struct *vma; | |
171 | ||
d8ed45c5 | 172 | mmap_write_lock(current->mm); |
f905bc44 PM |
173 | vma = find_vma(current->mm, (unsigned long)ret); |
174 | if (vma) | |
1c71222e | 175 | vm_flags_set(vma, VM_USERMAP); |
d8ed45c5 | 176 | mmap_write_unlock(current->mm); |
f905bc44 PM |
177 | } |
178 | ||
179 | return ret; | |
180 | } | |
ed81745a AN |
181 | |
182 | void *vmalloc_user(unsigned long size) | |
183 | { | |
184 | return __vmalloc_user_flags(size, GFP_KERNEL | __GFP_ZERO); | |
185 | } | |
f905bc44 PM |
186 | EXPORT_SYMBOL(vmalloc_user); |
187 | ||
b3bdda02 | 188 | struct page *vmalloc_to_page(const void *addr) |
1da177e4 LT |
189 | { |
190 | return virt_to_page(addr); | |
191 | } | |
b5073173 | 192 | EXPORT_SYMBOL(vmalloc_to_page); |
1da177e4 | 193 | |
b3bdda02 | 194 | unsigned long vmalloc_to_pfn(const void *addr) |
1da177e4 LT |
195 | { |
196 | return page_to_pfn(virt_to_page(addr)); | |
197 | } | |
b5073173 | 198 | EXPORT_SYMBOL(vmalloc_to_pfn); |
1da177e4 | 199 | |
4c91c07c | 200 | long vread_iter(struct iov_iter *iter, const char *addr, size_t count) |
1da177e4 | 201 | { |
9bde916b | 202 | /* Don't allow overflow */ |
4c91c07c LS |
203 | if ((unsigned long) addr + count < count) |
204 | count = -(unsigned long) addr; | |
9bde916b | 205 | |
4c91c07c | 206 | return copy_to_iter(addr, count, iter); |
1da177e4 LT |
207 | } |
208 | ||
1da177e4 | 209 | /* |
e1c05067 | 210 | * vmalloc - allocate virtually contiguous memory |
1da177e4 LT |
211 | * |
212 | * @size: allocation size | |
213 | * | |
214 | * Allocate enough pages to cover @size from the page level | |
e1c05067 | 215 | * allocator and map them into contiguous kernel virtual space. |
1da177e4 | 216 | * |
c1c8897f | 217 | * For tight control over page level allocator and protection flags |
1da177e4 LT |
218 | * use __vmalloc() instead. |
219 | */ | |
220 | void *vmalloc(unsigned long size) | |
221 | { | |
176056fd | 222 | return __vmalloc(size, GFP_KERNEL); |
1da177e4 | 223 | } |
f6138882 AM |
224 | EXPORT_SYMBOL(vmalloc); |
225 | ||
0fc74d82 LT |
226 | void *vmalloc_huge(unsigned long size, gfp_t gfp_mask) __weak __alias(__vmalloc); |
227 | ||
e1ca7788 | 228 | /* |
e1c05067 | 229 | * vzalloc - allocate virtually contiguous memory with zero fill |
e1ca7788 DY |
230 | * |
231 | * @size: allocation size | |
232 | * | |
233 | * Allocate enough pages to cover @size from the page level | |
e1c05067 | 234 | * allocator and map them into contiguous kernel virtual space. |
e1ca7788 DY |
235 | * The memory allocated is set to zero. |
236 | * | |
237 | * For tight control over page level allocator and protection flags | |
238 | * use __vmalloc() instead. | |
239 | */ | |
240 | void *vzalloc(unsigned long size) | |
241 | { | |
176056fd | 242 | return __vmalloc(size, GFP_KERNEL | __GFP_ZERO); |
e1ca7788 DY |
243 | } |
244 | EXPORT_SYMBOL(vzalloc); | |
245 | ||
246 | /** | |
247 | * vmalloc_node - allocate memory on a specific node | |
248 | * @size: allocation size | |
249 | * @node: numa node | |
250 | * | |
251 | * Allocate enough pages to cover @size from the page level | |
252 | * allocator and map them into contiguous kernel virtual space. | |
253 | * | |
254 | * For tight control over page level allocator and protection flags | |
255 | * use __vmalloc() instead. | |
256 | */ | |
f6138882 AM |
257 | void *vmalloc_node(unsigned long size, int node) |
258 | { | |
259 | return vmalloc(size); | |
260 | } | |
9a14f653 | 261 | EXPORT_SYMBOL(vmalloc_node); |
e1ca7788 DY |
262 | |
263 | /** | |
264 | * vzalloc_node - allocate memory on a specific node with zero fill | |
265 | * @size: allocation size | |
266 | * @node: numa node | |
267 | * | |
268 | * Allocate enough pages to cover @size from the page level | |
269 | * allocator and map them into contiguous kernel virtual space. | |
270 | * The memory allocated is set to zero. | |
271 | * | |
272 | * For tight control over page level allocator and protection flags | |
273 | * use __vmalloc() instead. | |
274 | */ | |
275 | void *vzalloc_node(unsigned long size, int node) | |
276 | { | |
277 | return vzalloc(size); | |
278 | } | |
279 | EXPORT_SYMBOL(vzalloc_node); | |
1da177e4 | 280 | |
b5073173 PM |
281 | /** |
282 | * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) | |
1da177e4 LT |
283 | * @size: allocation size |
284 | * | |
285 | * Allocate enough 32bit PA addressable pages to cover @size from the | |
e1c05067 | 286 | * page level allocator and map them into contiguous kernel virtual space. |
1da177e4 LT |
287 | */ |
288 | void *vmalloc_32(unsigned long size) | |
289 | { | |
88dca4ca | 290 | return __vmalloc(size, GFP_KERNEL); |
1da177e4 | 291 | } |
b5073173 PM |
292 | EXPORT_SYMBOL(vmalloc_32); |
293 | ||
294 | /** | |
295 | * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory | |
296 | * @size: allocation size | |
297 | * | |
298 | * The resulting memory area is 32bit addressable and zeroed so it can be | |
299 | * mapped to userspace without leaking data. | |
f905bc44 PM |
300 | * |
301 | * VM_USERMAP is set on the corresponding VMA so that subsequent calls to | |
302 | * remap_vmalloc_range() are permissible. | |
b5073173 PM |
303 | */ |
304 | void *vmalloc_32_user(unsigned long size) | |
305 | { | |
f905bc44 PM |
306 | /* |
307 | * We'll have to sort out the ZONE_DMA bits for 64-bit, | |
308 | * but for now this can simply use vmalloc_user() directly. | |
309 | */ | |
310 | return vmalloc_user(size); | |
b5073173 PM |
311 | } |
312 | EXPORT_SYMBOL(vmalloc_32_user); | |
1da177e4 LT |
313 | |
314 | void *vmap(struct page **pages, unsigned int count, unsigned long flags, pgprot_t prot) | |
315 | { | |
316 | BUG(); | |
317 | return NULL; | |
318 | } | |
b5073173 | 319 | EXPORT_SYMBOL(vmap); |
1da177e4 | 320 | |
b3bdda02 | 321 | void vunmap(const void *addr) |
1da177e4 LT |
322 | { |
323 | BUG(); | |
324 | } | |
b5073173 | 325 | EXPORT_SYMBOL(vunmap); |
1da177e4 | 326 | |
d4efd79a | 327 | void *vm_map_ram(struct page **pages, unsigned int count, int node) |
eb6434d9 PM |
328 | { |
329 | BUG(); | |
330 | return NULL; | |
331 | } | |
332 | EXPORT_SYMBOL(vm_map_ram); | |
333 | ||
334 | void vm_unmap_ram(const void *mem, unsigned int count) | |
335 | { | |
336 | BUG(); | |
337 | } | |
338 | EXPORT_SYMBOL(vm_unmap_ram); | |
339 | ||
340 | void vm_unmap_aliases(void) | |
341 | { | |
342 | } | |
343 | EXPORT_SYMBOL_GPL(vm_unmap_aliases); | |
344 | ||
29c185e5 PM |
345 | void free_vm_area(struct vm_struct *area) |
346 | { | |
347 | BUG(); | |
348 | } | |
349 | EXPORT_SYMBOL_GPL(free_vm_area); | |
350 | ||
b5073173 PM |
351 | int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, |
352 | struct page *page) | |
353 | { | |
354 | return -EINVAL; | |
355 | } | |
356 | EXPORT_SYMBOL(vm_insert_page); | |
357 | ||
62346c6c JA |
358 | int vm_insert_pages(struct vm_area_struct *vma, unsigned long addr, |
359 | struct page **pages, unsigned long *num) | |
360 | { | |
361 | return -EINVAL; | |
362 | } | |
363 | EXPORT_SYMBOL(vm_insert_pages); | |
364 | ||
a667d745 SJ |
365 | int vm_map_pages(struct vm_area_struct *vma, struct page **pages, |
366 | unsigned long num) | |
367 | { | |
368 | return -EINVAL; | |
369 | } | |
370 | EXPORT_SYMBOL(vm_map_pages); | |
371 | ||
372 | int vm_map_pages_zero(struct vm_area_struct *vma, struct page **pages, | |
373 | unsigned long num) | |
374 | { | |
375 | return -EINVAL; | |
376 | } | |
377 | EXPORT_SYMBOL(vm_map_pages_zero); | |
378 | ||
1da177e4 LT |
379 | /* |
380 | * sys_brk() for the most part doesn't need the global kernel | |
381 | * lock, except when an application is doing something nasty | |
382 | * like trying to un-brk an area that has already been mapped | |
383 | * to a regular file. in this case, the unmapping will need | |
384 | * to invoke file system routines that need the global lock. | |
385 | */ | |
6a6160a7 | 386 | SYSCALL_DEFINE1(brk, unsigned long, brk) |
1da177e4 LT |
387 | { |
388 | struct mm_struct *mm = current->mm; | |
389 | ||
390 | if (brk < mm->start_brk || brk > mm->context.end_brk) | |
391 | return mm->brk; | |
392 | ||
393 | if (mm->brk == brk) | |
394 | return mm->brk; | |
395 | ||
396 | /* | |
397 | * Always allow shrinking brk | |
398 | */ | |
399 | if (brk <= mm->brk) { | |
400 | mm->brk = brk; | |
401 | return brk; | |
402 | } | |
403 | ||
404 | /* | |
405 | * Ok, looks good - let it rip. | |
406 | */ | |
a75a2df6 | 407 | flush_icache_user_range(mm->brk, brk); |
1da177e4 LT |
408 | return mm->brk = brk; |
409 | } | |
410 | ||
8feae131 | 411 | /* |
3edf41d8 | 412 | * initialise the percpu counter for VM and region record slabs |
8feae131 DH |
413 | */ |
414 | void __init mmap_init(void) | |
1da177e4 | 415 | { |
00a62ce9 KM |
416 | int ret; |
417 | ||
908c7f19 | 418 | ret = percpu_counter_init(&vm_committed_as, 0, GFP_KERNEL); |
00a62ce9 | 419 | VM_BUG_ON(ret); |
5d097056 | 420 | vm_region_jar = KMEM_CACHE(vm_region, SLAB_PANIC|SLAB_ACCOUNT); |
1da177e4 | 421 | } |
1da177e4 | 422 | |
3034097a | 423 | /* |
8feae131 DH |
424 | * validate the region tree |
425 | * - the caller must hold the region lock | |
3034097a | 426 | */ |
8feae131 DH |
427 | #ifdef CONFIG_DEBUG_NOMMU_REGIONS |
428 | static noinline void validate_nommu_regions(void) | |
3034097a | 429 | { |
8feae131 DH |
430 | struct vm_region *region, *last; |
431 | struct rb_node *p, *lastp; | |
3034097a | 432 | |
8feae131 DH |
433 | lastp = rb_first(&nommu_region_tree); |
434 | if (!lastp) | |
435 | return; | |
436 | ||
437 | last = rb_entry(lastp, struct vm_region, vm_rb); | |
c9427bc0 GT |
438 | BUG_ON(last->vm_end <= last->vm_start); |
439 | BUG_ON(last->vm_top < last->vm_end); | |
8feae131 DH |
440 | |
441 | while ((p = rb_next(lastp))) { | |
442 | region = rb_entry(p, struct vm_region, vm_rb); | |
443 | last = rb_entry(lastp, struct vm_region, vm_rb); | |
444 | ||
c9427bc0 GT |
445 | BUG_ON(region->vm_end <= region->vm_start); |
446 | BUG_ON(region->vm_top < region->vm_end); | |
447 | BUG_ON(region->vm_start < last->vm_top); | |
3034097a | 448 | |
8feae131 DH |
449 | lastp = p; |
450 | } | |
3034097a | 451 | } |
8feae131 | 452 | #else |
33e5d769 DH |
453 | static void validate_nommu_regions(void) |
454 | { | |
455 | } | |
8feae131 | 456 | #endif |
3034097a DH |
457 | |
458 | /* | |
8feae131 | 459 | * add a region into the global tree |
3034097a | 460 | */ |
8feae131 | 461 | static void add_nommu_region(struct vm_region *region) |
3034097a | 462 | { |
8feae131 DH |
463 | struct vm_region *pregion; |
464 | struct rb_node **p, *parent; | |
3034097a | 465 | |
8feae131 DH |
466 | validate_nommu_regions(); |
467 | ||
8feae131 DH |
468 | parent = NULL; |
469 | p = &nommu_region_tree.rb_node; | |
470 | while (*p) { | |
471 | parent = *p; | |
472 | pregion = rb_entry(parent, struct vm_region, vm_rb); | |
473 | if (region->vm_start < pregion->vm_start) | |
474 | p = &(*p)->rb_left; | |
475 | else if (region->vm_start > pregion->vm_start) | |
476 | p = &(*p)->rb_right; | |
477 | else if (pregion == region) | |
478 | return; | |
479 | else | |
480 | BUG(); | |
3034097a DH |
481 | } |
482 | ||
8feae131 DH |
483 | rb_link_node(®ion->vm_rb, parent, p); |
484 | rb_insert_color(®ion->vm_rb, &nommu_region_tree); | |
3034097a | 485 | |
8feae131 | 486 | validate_nommu_regions(); |
3034097a | 487 | } |
3034097a | 488 | |
930e652a | 489 | /* |
8feae131 | 490 | * delete a region from the global tree |
930e652a | 491 | */ |
8feae131 | 492 | static void delete_nommu_region(struct vm_region *region) |
930e652a | 493 | { |
8feae131 | 494 | BUG_ON(!nommu_region_tree.rb_node); |
930e652a | 495 | |
8feae131 DH |
496 | validate_nommu_regions(); |
497 | rb_erase(®ion->vm_rb, &nommu_region_tree); | |
498 | validate_nommu_regions(); | |
57c8f63e GU |
499 | } |
500 | ||
6fa5f80b | 501 | /* |
8feae131 | 502 | * free a contiguous series of pages |
6fa5f80b | 503 | */ |
8feae131 | 504 | static void free_page_series(unsigned long from, unsigned long to) |
6fa5f80b | 505 | { |
8feae131 | 506 | for (; from < to; from += PAGE_SIZE) { |
9330723c | 507 | struct page *page = virt_to_page((void *)from); |
8feae131 | 508 | |
33e5d769 | 509 | atomic_long_dec(&mmap_pages_allocated); |
8feae131 | 510 | put_page(page); |
6fa5f80b | 511 | } |
6fa5f80b DH |
512 | } |
513 | ||
3034097a | 514 | /* |
8feae131 | 515 | * release a reference to a region |
33e5d769 | 516 | * - the caller must hold the region semaphore for writing, which this releases |
dd8632a1 | 517 | * - the region may not have been added to the tree yet, in which case vm_top |
8feae131 | 518 | * will equal vm_start |
3034097a | 519 | */ |
8feae131 DH |
520 | static void __put_nommu_region(struct vm_region *region) |
521 | __releases(nommu_region_sem) | |
1da177e4 | 522 | { |
8feae131 | 523 | BUG_ON(!nommu_region_tree.rb_node); |
1da177e4 | 524 | |
1e2ae599 | 525 | if (--region->vm_usage == 0) { |
dd8632a1 | 526 | if (region->vm_top > region->vm_start) |
8feae131 DH |
527 | delete_nommu_region(region); |
528 | up_write(&nommu_region_sem); | |
529 | ||
530 | if (region->vm_file) | |
531 | fput(region->vm_file); | |
532 | ||
533 | /* IO memory and memory shared directly out of the pagecache | |
534 | * from ramfs/tmpfs mustn't be released here */ | |
22cc877b | 535 | if (region->vm_flags & VM_MAPPED_COPY) |
dd8632a1 | 536 | free_page_series(region->vm_start, region->vm_top); |
8feae131 DH |
537 | kmem_cache_free(vm_region_jar, region); |
538 | } else { | |
539 | up_write(&nommu_region_sem); | |
1da177e4 | 540 | } |
8feae131 | 541 | } |
1da177e4 | 542 | |
8feae131 DH |
543 | /* |
544 | * release a reference to a region | |
545 | */ | |
546 | static void put_nommu_region(struct vm_region *region) | |
547 | { | |
548 | down_write(&nommu_region_sem); | |
549 | __put_nommu_region(region); | |
1da177e4 LT |
550 | } |
551 | ||
8220543d | 552 | static void setup_vma_to_mm(struct vm_area_struct *vma, struct mm_struct *mm) |
1da177e4 | 553 | { |
8feae131 | 554 | vma->vm_mm = mm; |
1da177e4 LT |
555 | |
556 | /* add the VMA to the mapping */ | |
557 | if (vma->vm_file) { | |
8220543d | 558 | struct address_space *mapping = vma->vm_file->f_mapping; |
1da177e4 | 559 | |
83cde9e8 | 560 | i_mmap_lock_write(mapping); |
1da177e4 | 561 | flush_dcache_mmap_lock(mapping); |
6b2dbba8 | 562 | vma_interval_tree_insert(vma, &mapping->i_mmap); |
1da177e4 | 563 | flush_dcache_mmap_unlock(mapping); |
83cde9e8 | 564 | i_mmap_unlock_write(mapping); |
1da177e4 | 565 | } |
8220543d | 566 | } |
1da177e4 | 567 | |
8220543d MWO |
568 | static void cleanup_vma_from_mm(struct vm_area_struct *vma) |
569 | { | |
7964cf8c | 570 | vma->vm_mm->map_count--; |
1da177e4 LT |
571 | /* remove the VMA from the mapping */ |
572 | if (vma->vm_file) { | |
7964cf8c | 573 | struct address_space *mapping; |
1da177e4 LT |
574 | mapping = vma->vm_file->f_mapping; |
575 | ||
83cde9e8 | 576 | i_mmap_lock_write(mapping); |
1da177e4 | 577 | flush_dcache_mmap_lock(mapping); |
6b2dbba8 | 578 | vma_interval_tree_remove(vma, &mapping->i_mmap); |
1da177e4 | 579 | flush_dcache_mmap_unlock(mapping); |
83cde9e8 | 580 | i_mmap_unlock_write(mapping); |
1da177e4 | 581 | } |
8220543d | 582 | } |
47d9644d | 583 | |
8220543d MWO |
584 | /* |
585 | * delete a VMA from its owning mm_struct and address space | |
586 | */ | |
587 | static int delete_vma_from_mm(struct vm_area_struct *vma) | |
588 | { | |
47d9644d | 589 | VMA_ITERATOR(vmi, vma->vm_mm, vma->vm_start); |
8220543d | 590 | |
b5df0922 LH |
591 | vma_iter_config(&vmi, vma->vm_start, vma->vm_end); |
592 | if (vma_iter_prealloc(&vmi, vma)) { | |
8220543d MWO |
593 | pr_warn("Allocation of vma tree for process %d failed\n", |
594 | current->pid); | |
595 | return -ENOMEM; | |
596 | } | |
597 | cleanup_vma_from_mm(vma); | |
1da177e4 | 598 | |
8feae131 | 599 | /* remove from the MM's tree and list */ |
b5df0922 | 600 | vma_iter_clear(&vmi); |
8220543d | 601 | return 0; |
8feae131 | 602 | } |
8feae131 DH |
603 | /* |
604 | * destroy a VMA record | |
605 | */ | |
606 | static void delete_vma(struct mm_struct *mm, struct vm_area_struct *vma) | |
607 | { | |
8feae131 DH |
608 | if (vma->vm_ops && vma->vm_ops->close) |
609 | vma->vm_ops->close(vma); | |
e9714acf | 610 | if (vma->vm_file) |
8feae131 | 611 | fput(vma->vm_file); |
8feae131 | 612 | put_nommu_region(vma->vm_region); |
3928d4f5 | 613 | vm_area_free(vma); |
8feae131 DH |
614 | } |
615 | ||
abdba2dd LH |
616 | struct vm_area_struct *find_vma_intersection(struct mm_struct *mm, |
617 | unsigned long start_addr, | |
618 | unsigned long end_addr) | |
619 | { | |
620 | unsigned long index = start_addr; | |
621 | ||
622 | mmap_assert_locked(mm); | |
623 | return mt_find(&mm->mm_mt, &index, end_addr - 1); | |
624 | } | |
625 | EXPORT_SYMBOL(find_vma_intersection); | |
626 | ||
8feae131 DH |
627 | /* |
628 | * look up the first VMA in which addr resides, NULL if none | |
c1e8d7c6 | 629 | * - should be called with mm->mmap_lock at least held readlocked |
8feae131 DH |
630 | */ |
631 | struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) | |
632 | { | |
47d9644d | 633 | VMA_ITERATOR(vmi, mm, addr); |
8feae131 | 634 | |
47d9644d | 635 | return vma_iter_load(&vmi); |
8feae131 DH |
636 | } |
637 | EXPORT_SYMBOL(find_vma); | |
638 | ||
d85a143b LT |
639 | /* |
640 | * At least xtensa ends up having protection faults even with no | |
641 | * MMU.. No stack expansion, at least. | |
642 | */ | |
643 | struct vm_area_struct *lock_mm_and_find_vma(struct mm_struct *mm, | |
644 | unsigned long addr, struct pt_regs *regs) | |
645 | { | |
03f88937 MF |
646 | struct vm_area_struct *vma; |
647 | ||
d85a143b | 648 | mmap_read_lock(mm); |
03f88937 MF |
649 | vma = vma_lookup(mm, addr); |
650 | if (!vma) | |
651 | mmap_read_unlock(mm); | |
652 | return vma; | |
d85a143b LT |
653 | } |
654 | ||
8feae131 DH |
655 | /* |
656 | * expand a stack to a given address | |
657 | * - not supported under NOMMU conditions | |
658 | */ | |
8d7071af | 659 | int expand_stack_locked(struct vm_area_struct *vma, unsigned long addr) |
8feae131 DH |
660 | { |
661 | return -ENOMEM; | |
662 | } | |
663 | ||
8d7071af LT |
664 | struct vm_area_struct *expand_stack(struct mm_struct *mm, unsigned long addr) |
665 | { | |
666 | mmap_read_unlock(mm); | |
667 | return NULL; | |
668 | } | |
669 | ||
8feae131 DH |
670 | /* |
671 | * look up the first VMA exactly that exactly matches addr | |
c1e8d7c6 | 672 | * - should be called with mm->mmap_lock at least held readlocked |
8feae131 DH |
673 | */ |
674 | static struct vm_area_struct *find_vma_exact(struct mm_struct *mm, | |
675 | unsigned long addr, | |
676 | unsigned long len) | |
677 | { | |
678 | struct vm_area_struct *vma; | |
8feae131 | 679 | unsigned long end = addr + len; |
47d9644d | 680 | VMA_ITERATOR(vmi, mm, addr); |
8feae131 | 681 | |
47d9644d | 682 | vma = vma_iter_load(&vmi); |
524e00b3 LH |
683 | if (!vma) |
684 | return NULL; | |
685 | if (vma->vm_start != addr) | |
686 | return NULL; | |
687 | if (vma->vm_end != end) | |
688 | return NULL; | |
689 | ||
524e00b3 | 690 | return vma; |
1da177e4 LT |
691 | } |
692 | ||
693 | /* | |
694 | * determine whether a mapping should be permitted and, if so, what sort of | |
695 | * mapping we're capable of supporting | |
696 | */ | |
697 | static int validate_mmap_request(struct file *file, | |
698 | unsigned long addr, | |
699 | unsigned long len, | |
700 | unsigned long prot, | |
701 | unsigned long flags, | |
702 | unsigned long pgoff, | |
703 | unsigned long *_capabilities) | |
704 | { | |
8feae131 | 705 | unsigned long capabilities, rlen; |
1da177e4 LT |
706 | int ret; |
707 | ||
708 | /* do the simple checks first */ | |
22cc877b | 709 | if (flags & MAP_FIXED) |
1da177e4 | 710 | return -EINVAL; |
1da177e4 LT |
711 | |
712 | if ((flags & MAP_TYPE) != MAP_PRIVATE && | |
713 | (flags & MAP_TYPE) != MAP_SHARED) | |
714 | return -EINVAL; | |
715 | ||
f81cff0d | 716 | if (!len) |
1da177e4 LT |
717 | return -EINVAL; |
718 | ||
f81cff0d | 719 | /* Careful about overflows.. */ |
8feae131 DH |
720 | rlen = PAGE_ALIGN(len); |
721 | if (!rlen || rlen > TASK_SIZE) | |
f81cff0d MF |
722 | return -ENOMEM; |
723 | ||
1da177e4 | 724 | /* offset overflow? */ |
8feae131 | 725 | if ((pgoff + (rlen >> PAGE_SHIFT)) < pgoff) |
f81cff0d | 726 | return -EOVERFLOW; |
1da177e4 LT |
727 | |
728 | if (file) { | |
1da177e4 | 729 | /* files must support mmap */ |
72c2d531 | 730 | if (!file->f_op->mmap) |
1da177e4 LT |
731 | return -ENODEV; |
732 | ||
733 | /* work out if what we've got could possibly be shared | |
734 | * - we support chardevs that provide their own "memory" | |
735 | * - we support files/blockdevs that are memory backed | |
736 | */ | |
b4caecd4 CH |
737 | if (file->f_op->mmap_capabilities) { |
738 | capabilities = file->f_op->mmap_capabilities(file); | |
739 | } else { | |
1da177e4 LT |
740 | /* no explicit capabilities set, so assume some |
741 | * defaults */ | |
496ad9aa | 742 | switch (file_inode(file)->i_mode & S_IFMT) { |
1da177e4 LT |
743 | case S_IFREG: |
744 | case S_IFBLK: | |
b4caecd4 | 745 | capabilities = NOMMU_MAP_COPY; |
1da177e4 LT |
746 | break; |
747 | ||
748 | case S_IFCHR: | |
749 | capabilities = | |
b4caecd4 CH |
750 | NOMMU_MAP_DIRECT | |
751 | NOMMU_MAP_READ | | |
752 | NOMMU_MAP_WRITE; | |
1da177e4 LT |
753 | break; |
754 | ||
755 | default: | |
756 | return -EINVAL; | |
757 | } | |
758 | } | |
759 | ||
760 | /* eliminate any capabilities that we can't support on this | |
761 | * device */ | |
762 | if (!file->f_op->get_unmapped_area) | |
b4caecd4 | 763 | capabilities &= ~NOMMU_MAP_DIRECT; |
6e242a1c | 764 | if (!(file->f_mode & FMODE_CAN_READ)) |
b4caecd4 | 765 | capabilities &= ~NOMMU_MAP_COPY; |
1da177e4 | 766 | |
28d7a6ae GY |
767 | /* The file shall have been opened with read permission. */ |
768 | if (!(file->f_mode & FMODE_READ)) | |
769 | return -EACCES; | |
770 | ||
1da177e4 LT |
771 | if (flags & MAP_SHARED) { |
772 | /* do checks for writing, appending and locking */ | |
773 | if ((prot & PROT_WRITE) && | |
774 | !(file->f_mode & FMODE_WRITE)) | |
775 | return -EACCES; | |
776 | ||
496ad9aa | 777 | if (IS_APPEND(file_inode(file)) && |
1da177e4 LT |
778 | (file->f_mode & FMODE_WRITE)) |
779 | return -EACCES; | |
780 | ||
b4caecd4 | 781 | if (!(capabilities & NOMMU_MAP_DIRECT)) |
1da177e4 LT |
782 | return -ENODEV; |
783 | ||
1da177e4 | 784 | /* we mustn't privatise shared mappings */ |
b4caecd4 | 785 | capabilities &= ~NOMMU_MAP_COPY; |
ac714904 | 786 | } else { |
1da177e4 LT |
787 | /* we're going to read the file into private memory we |
788 | * allocate */ | |
b4caecd4 | 789 | if (!(capabilities & NOMMU_MAP_COPY)) |
1da177e4 LT |
790 | return -ENODEV; |
791 | ||
792 | /* we don't permit a private writable mapping to be | |
793 | * shared with the backing device */ | |
794 | if (prot & PROT_WRITE) | |
b4caecd4 | 795 | capabilities &= ~NOMMU_MAP_DIRECT; |
1da177e4 LT |
796 | } |
797 | ||
b4caecd4 CH |
798 | if (capabilities & NOMMU_MAP_DIRECT) { |
799 | if (((prot & PROT_READ) && !(capabilities & NOMMU_MAP_READ)) || | |
800 | ((prot & PROT_WRITE) && !(capabilities & NOMMU_MAP_WRITE)) || | |
801 | ((prot & PROT_EXEC) && !(capabilities & NOMMU_MAP_EXEC)) | |
3c7b2045 | 802 | ) { |
b4caecd4 | 803 | capabilities &= ~NOMMU_MAP_DIRECT; |
3c7b2045 | 804 | if (flags & MAP_SHARED) { |
22cc877b | 805 | pr_warn("MAP_SHARED not completely supported on !MMU\n"); |
3c7b2045 BS |
806 | return -EINVAL; |
807 | } | |
808 | } | |
809 | } | |
810 | ||
1da177e4 LT |
811 | /* handle executable mappings and implied executable |
812 | * mappings */ | |
90f8572b | 813 | if (path_noexec(&file->f_path)) { |
1da177e4 LT |
814 | if (prot & PROT_EXEC) |
815 | return -EPERM; | |
ac714904 | 816 | } else if ((prot & PROT_READ) && !(prot & PROT_EXEC)) { |
1da177e4 LT |
817 | /* handle implication of PROT_EXEC by PROT_READ */ |
818 | if (current->personality & READ_IMPLIES_EXEC) { | |
b4caecd4 | 819 | if (capabilities & NOMMU_MAP_EXEC) |
1da177e4 LT |
820 | prot |= PROT_EXEC; |
821 | } | |
ac714904 | 822 | } else if ((prot & PROT_READ) && |
1da177e4 | 823 | (prot & PROT_EXEC) && |
b4caecd4 | 824 | !(capabilities & NOMMU_MAP_EXEC) |
1da177e4 LT |
825 | ) { |
826 | /* backing file is not executable, try to copy */ | |
b4caecd4 | 827 | capabilities &= ~NOMMU_MAP_DIRECT; |
1da177e4 | 828 | } |
ac714904 | 829 | } else { |
1da177e4 LT |
830 | /* anonymous mappings are always memory backed and can be |
831 | * privately mapped | |
832 | */ | |
b4caecd4 | 833 | capabilities = NOMMU_MAP_COPY; |
1da177e4 LT |
834 | |
835 | /* handle PROT_EXEC implication by PROT_READ */ | |
836 | if ((prot & PROT_READ) && | |
837 | (current->personality & READ_IMPLIES_EXEC)) | |
838 | prot |= PROT_EXEC; | |
839 | } | |
840 | ||
841 | /* allow the security API to have its say */ | |
e5467859 | 842 | ret = security_mmap_addr(addr); |
1da177e4 LT |
843 | if (ret < 0) |
844 | return ret; | |
845 | ||
846 | /* looks okay */ | |
847 | *_capabilities = capabilities; | |
848 | return 0; | |
849 | } | |
850 | ||
851 | /* | |
852 | * we've determined that we can make the mapping, now translate what we | |
853 | * now know into VMA flags | |
854 | */ | |
855 | static unsigned long determine_vm_flags(struct file *file, | |
856 | unsigned long prot, | |
857 | unsigned long flags, | |
858 | unsigned long capabilities) | |
859 | { | |
860 | unsigned long vm_flags; | |
861 | ||
e6bfb709 | 862 | vm_flags = calc_vm_prot_bits(prot, 0) | calc_vm_flag_bits(flags); |
1da177e4 | 863 | |
b6b7a8fa DH |
864 | if (!file) { |
865 | /* | |
866 | * MAP_ANONYMOUS. MAP_SHARED is mapped to MAP_PRIVATE, because | |
867 | * there is no fork(). | |
868 | */ | |
3c7b2045 | 869 | vm_flags |= VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC; |
b6b7a8fa DH |
870 | } else if (flags & MAP_PRIVATE) { |
871 | /* MAP_PRIVATE file mapping */ | |
872 | if (capabilities & NOMMU_MAP_DIRECT) | |
873 | vm_flags |= (capabilities & NOMMU_VMFLAGS); | |
874 | else | |
875 | vm_flags |= VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC; | |
876 | ||
877 | if (!(prot & PROT_WRITE) && !current->ptrace) | |
878 | /* | |
879 | * R/O private file mapping which cannot be used to | |
880 | * modify memory, especially also not via active ptrace | |
881 | * (e.g., set breakpoints) or later by upgrading | |
882 | * permissions (no mprotect()). We can try overlaying | |
883 | * the file mapping, which will work e.g., on chardevs, | |
884 | * ramfs/tmpfs/shmfs and romfs/cramf. | |
885 | */ | |
886 | vm_flags |= VM_MAYOVERLAY; | |
3c7b2045 | 887 | } else { |
b6b7a8fa DH |
888 | /* MAP_SHARED file mapping: NOMMU_MAP_DIRECT is set. */ |
889 | vm_flags |= VM_SHARED | VM_MAYSHARE | | |
890 | (capabilities & NOMMU_VMFLAGS); | |
1da177e4 LT |
891 | } |
892 | ||
1da177e4 LT |
893 | return vm_flags; |
894 | } | |
895 | ||
896 | /* | |
8feae131 DH |
897 | * set up a shared mapping on a file (the driver or filesystem provides and |
898 | * pins the storage) | |
1da177e4 | 899 | */ |
8feae131 | 900 | static int do_mmap_shared_file(struct vm_area_struct *vma) |
1da177e4 LT |
901 | { |
902 | int ret; | |
903 | ||
f74ac015 | 904 | ret = call_mmap(vma->vm_file, vma); |
dd8632a1 PM |
905 | if (ret == 0) { |
906 | vma->vm_region->vm_top = vma->vm_region->vm_end; | |
645d83c5 | 907 | return 0; |
dd8632a1 | 908 | } |
1da177e4 LT |
909 | if (ret != -ENOSYS) |
910 | return ret; | |
911 | ||
3fa30460 DH |
912 | /* getting -ENOSYS indicates that direct mmap isn't possible (as |
913 | * opposed to tried but failed) so we can only give a suitable error as | |
914 | * it's not possible to make a private copy if MAP_SHARED was given */ | |
1da177e4 LT |
915 | return -ENODEV; |
916 | } | |
917 | ||
918 | /* | |
919 | * set up a private mapping or an anonymous shared mapping | |
920 | */ | |
8feae131 DH |
921 | static int do_mmap_private(struct vm_area_struct *vma, |
922 | struct vm_region *region, | |
645d83c5 DH |
923 | unsigned long len, |
924 | unsigned long capabilities) | |
1da177e4 | 925 | { |
dbc8358c | 926 | unsigned long total, point; |
1da177e4 | 927 | void *base; |
8feae131 | 928 | int ret, order; |
1da177e4 | 929 | |
b6b7a8fa DH |
930 | /* |
931 | * Invoke the file's mapping function so that it can keep track of | |
932 | * shared mappings on devices or memory. VM_MAYOVERLAY will be set if | |
933 | * it may attempt to share, which will make is_nommu_shared_mapping() | |
934 | * happy. | |
1da177e4 | 935 | */ |
b4caecd4 | 936 | if (capabilities & NOMMU_MAP_DIRECT) { |
f74ac015 | 937 | ret = call_mmap(vma->vm_file, vma); |
fc4f4be9 DH |
938 | /* shouldn't return success if we're not sharing */ |
939 | if (WARN_ON_ONCE(!is_nommu_shared_mapping(vma->vm_flags))) | |
940 | ret = -ENOSYS; | |
dd8632a1 | 941 | if (ret == 0) { |
dd8632a1 | 942 | vma->vm_region->vm_top = vma->vm_region->vm_end; |
645d83c5 | 943 | return 0; |
1da177e4 | 944 | } |
dd8632a1 PM |
945 | if (ret != -ENOSYS) |
946 | return ret; | |
1da177e4 LT |
947 | |
948 | /* getting an ENOSYS error indicates that direct mmap isn't | |
949 | * possible (as opposed to tried but failed) so we'll try to | |
950 | * make a private copy of the data and map that instead */ | |
951 | } | |
952 | ||
8feae131 | 953 | |
1da177e4 LT |
954 | /* allocate some memory to hold the mapping |
955 | * - note that this may not return a page-aligned address if the object | |
956 | * we're allocating is smaller than a page | |
957 | */ | |
f67d9b15 | 958 | order = get_order(len); |
8feae131 | 959 | total = 1 << order; |
f67d9b15 | 960 | point = len >> PAGE_SHIFT; |
dd8632a1 | 961 | |
dbc8358c | 962 | /* we don't want to allocate a power-of-2 sized page set */ |
22cc877b | 963 | if (sysctl_nr_trim_pages && total - point >= sysctl_nr_trim_pages) |
dbc8358c | 964 | total = point; |
8feae131 | 965 | |
da616534 | 966 | base = alloc_pages_exact(total << PAGE_SHIFT, GFP_KERNEL); |
dbc8358c JK |
967 | if (!base) |
968 | goto enomem; | |
969 | ||
970 | atomic_long_add(total, &mmap_pages_allocated); | |
1da177e4 | 971 | |
1c71222e SB |
972 | vm_flags_set(vma, VM_MAPPED_COPY); |
973 | region->vm_flags = vma->vm_flags; | |
8feae131 | 974 | region->vm_start = (unsigned long) base; |
f67d9b15 | 975 | region->vm_end = region->vm_start + len; |
dd8632a1 | 976 | region->vm_top = region->vm_start + (total << PAGE_SHIFT); |
8feae131 DH |
977 | |
978 | vma->vm_start = region->vm_start; | |
979 | vma->vm_end = region->vm_start + len; | |
1da177e4 LT |
980 | |
981 | if (vma->vm_file) { | |
982 | /* read the contents of a file into the copy */ | |
1da177e4 LT |
983 | loff_t fpos; |
984 | ||
985 | fpos = vma->vm_pgoff; | |
986 | fpos <<= PAGE_SHIFT; | |
987 | ||
b4bf802a | 988 | ret = kernel_read(vma->vm_file, base, len, &fpos); |
1da177e4 LT |
989 | if (ret < 0) |
990 | goto error_free; | |
991 | ||
992 | /* clear the last little bit */ | |
f67d9b15 BL |
993 | if (ret < len) |
994 | memset(base + ret, 0, len - ret); | |
1da177e4 | 995 | |
bfd40eaf KS |
996 | } else { |
997 | vma_set_anonymous(vma); | |
1da177e4 LT |
998 | } |
999 | ||
1000 | return 0; | |
1001 | ||
1002 | error_free: | |
7223bb4a | 1003 | free_page_series(region->vm_start, region->vm_top); |
8feae131 DH |
1004 | region->vm_start = vma->vm_start = 0; |
1005 | region->vm_end = vma->vm_end = 0; | |
dd8632a1 | 1006 | region->vm_top = 0; |
1da177e4 LT |
1007 | return ret; |
1008 | ||
1009 | enomem: | |
b1de0d13 | 1010 | pr_err("Allocation of length %lu from process %d (%s) failed\n", |
05ae6fa3 | 1011 | len, current->pid, current->comm); |
1279aa06 | 1012 | show_mem(); |
1da177e4 LT |
1013 | return -ENOMEM; |
1014 | } | |
1015 | ||
1016 | /* | |
1017 | * handle mapping creation for uClinux | |
1018 | */ | |
1fcfd8db ON |
1019 | unsigned long do_mmap(struct file *file, |
1020 | unsigned long addr, | |
1021 | unsigned long len, | |
1022 | unsigned long prot, | |
1023 | unsigned long flags, | |
592b5fad | 1024 | vm_flags_t vm_flags, |
1fcfd8db | 1025 | unsigned long pgoff, |
897ab3e0 MR |
1026 | unsigned long *populate, |
1027 | struct list_head *uf) | |
1da177e4 | 1028 | { |
8feae131 DH |
1029 | struct vm_area_struct *vma; |
1030 | struct vm_region *region; | |
1da177e4 | 1031 | struct rb_node *rb; |
1fcfd8db | 1032 | unsigned long capabilities, result; |
1da177e4 | 1033 | int ret; |
47d9644d | 1034 | VMA_ITERATOR(vmi, current->mm, 0); |
1da177e4 | 1035 | |
41badc15 | 1036 | *populate = 0; |
bebeb3d6 | 1037 | |
1da177e4 LT |
1038 | /* decide whether we should attempt the mapping, and if so what sort of |
1039 | * mapping */ | |
1040 | ret = validate_mmap_request(file, addr, len, prot, flags, pgoff, | |
1041 | &capabilities); | |
22cc877b | 1042 | if (ret < 0) |
1da177e4 LT |
1043 | return ret; |
1044 | ||
06aab5a3 DH |
1045 | /* we ignore the address hint */ |
1046 | addr = 0; | |
f67d9b15 | 1047 | len = PAGE_ALIGN(len); |
06aab5a3 | 1048 | |
1da177e4 LT |
1049 | /* we've determined that we can make the mapping, now translate what we |
1050 | * now know into VMA flags */ | |
592b5fad | 1051 | vm_flags |= determine_vm_flags(file, prot, flags, capabilities); |
1da177e4 | 1052 | |
8220543d | 1053 | |
8feae131 DH |
1054 | /* we're going to need to record the mapping */ |
1055 | region = kmem_cache_zalloc(vm_region_jar, GFP_KERNEL); | |
1056 | if (!region) | |
1057 | goto error_getting_region; | |
1058 | ||
490fc053 | 1059 | vma = vm_area_alloc(current->mm); |
8feae131 DH |
1060 | if (!vma) |
1061 | goto error_getting_vma; | |
1da177e4 | 1062 | |
1e2ae599 | 1063 | region->vm_usage = 1; |
8feae131 DH |
1064 | region->vm_flags = vm_flags; |
1065 | region->vm_pgoff = pgoff; | |
1066 | ||
1c71222e | 1067 | vm_flags_init(vma, vm_flags); |
8feae131 | 1068 | vma->vm_pgoff = pgoff; |
1da177e4 | 1069 | |
8feae131 | 1070 | if (file) { |
cb0942b8 AV |
1071 | region->vm_file = get_file(file); |
1072 | vma->vm_file = get_file(file); | |
8feae131 DH |
1073 | } |
1074 | ||
1075 | down_write(&nommu_region_sem); | |
1076 | ||
1077 | /* if we want to share, we need to check for regions created by other | |
1da177e4 | 1078 | * mmap() calls that overlap with our proposed mapping |
8feae131 | 1079 | * - we can only share with a superset match on most regular files |
1da177e4 LT |
1080 | * - shared mappings on character devices and memory backed files are |
1081 | * permitted to overlap inexactly as far as we are concerned for in | |
1082 | * these cases, sharing is handled in the driver or filesystem rather | |
1083 | * than here | |
1084 | */ | |
fc4f4be9 | 1085 | if (is_nommu_shared_mapping(vm_flags)) { |
8feae131 DH |
1086 | struct vm_region *pregion; |
1087 | unsigned long pglen, rpglen, pgend, rpgend, start; | |
1da177e4 | 1088 | |
8feae131 DH |
1089 | pglen = (len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
1090 | pgend = pgoff + pglen; | |
165b2392 | 1091 | |
8feae131 DH |
1092 | for (rb = rb_first(&nommu_region_tree); rb; rb = rb_next(rb)) { |
1093 | pregion = rb_entry(rb, struct vm_region, vm_rb); | |
1da177e4 | 1094 | |
fc4f4be9 | 1095 | if (!is_nommu_shared_mapping(pregion->vm_flags)) |
1da177e4 LT |
1096 | continue; |
1097 | ||
1098 | /* search for overlapping mappings on the same file */ | |
496ad9aa AV |
1099 | if (file_inode(pregion->vm_file) != |
1100 | file_inode(file)) | |
1da177e4 LT |
1101 | continue; |
1102 | ||
8feae131 | 1103 | if (pregion->vm_pgoff >= pgend) |
1da177e4 LT |
1104 | continue; |
1105 | ||
8feae131 DH |
1106 | rpglen = pregion->vm_end - pregion->vm_start; |
1107 | rpglen = (rpglen + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
1108 | rpgend = pregion->vm_pgoff + rpglen; | |
1109 | if (pgoff >= rpgend) | |
1da177e4 LT |
1110 | continue; |
1111 | ||
8feae131 DH |
1112 | /* handle inexactly overlapping matches between |
1113 | * mappings */ | |
1114 | if ((pregion->vm_pgoff != pgoff || rpglen != pglen) && | |
1115 | !(pgoff >= pregion->vm_pgoff && pgend <= rpgend)) { | |
1116 | /* new mapping is not a subset of the region */ | |
b4caecd4 | 1117 | if (!(capabilities & NOMMU_MAP_DIRECT)) |
1da177e4 LT |
1118 | goto sharing_violation; |
1119 | continue; | |
1120 | } | |
1121 | ||
8feae131 | 1122 | /* we've found a region we can share */ |
1e2ae599 | 1123 | pregion->vm_usage++; |
8feae131 DH |
1124 | vma->vm_region = pregion; |
1125 | start = pregion->vm_start; | |
1126 | start += (pgoff - pregion->vm_pgoff) << PAGE_SHIFT; | |
1127 | vma->vm_start = start; | |
1128 | vma->vm_end = start + len; | |
1129 | ||
22cc877b | 1130 | if (pregion->vm_flags & VM_MAPPED_COPY) |
1c71222e | 1131 | vm_flags_set(vma, VM_MAPPED_COPY); |
22cc877b | 1132 | else { |
8feae131 DH |
1133 | ret = do_mmap_shared_file(vma); |
1134 | if (ret < 0) { | |
1135 | vma->vm_region = NULL; | |
1136 | vma->vm_start = 0; | |
1137 | vma->vm_end = 0; | |
1e2ae599 | 1138 | pregion->vm_usage--; |
8feae131 DH |
1139 | pregion = NULL; |
1140 | goto error_just_free; | |
1141 | } | |
1142 | } | |
1143 | fput(region->vm_file); | |
1144 | kmem_cache_free(vm_region_jar, region); | |
1145 | region = pregion; | |
1146 | result = start; | |
1147 | goto share; | |
1da177e4 LT |
1148 | } |
1149 | ||
1da177e4 LT |
1150 | /* obtain the address at which to make a shared mapping |
1151 | * - this is the hook for quasi-memory character devices to | |
1152 | * tell us the location of a shared mapping | |
1153 | */ | |
b4caecd4 | 1154 | if (capabilities & NOMMU_MAP_DIRECT) { |
1da177e4 LT |
1155 | addr = file->f_op->get_unmapped_area(file, addr, len, |
1156 | pgoff, flags); | |
bb005a59 | 1157 | if (IS_ERR_VALUE(addr)) { |
1da177e4 | 1158 | ret = addr; |
bb005a59 | 1159 | if (ret != -ENOSYS) |
8feae131 | 1160 | goto error_just_free; |
1da177e4 LT |
1161 | |
1162 | /* the driver refused to tell us where to site | |
1163 | * the mapping so we'll have to attempt to copy | |
1164 | * it */ | |
bb005a59 | 1165 | ret = -ENODEV; |
b4caecd4 | 1166 | if (!(capabilities & NOMMU_MAP_COPY)) |
8feae131 | 1167 | goto error_just_free; |
1da177e4 | 1168 | |
b4caecd4 | 1169 | capabilities &= ~NOMMU_MAP_DIRECT; |
8feae131 DH |
1170 | } else { |
1171 | vma->vm_start = region->vm_start = addr; | |
1172 | vma->vm_end = region->vm_end = addr + len; | |
1da177e4 LT |
1173 | } |
1174 | } | |
1175 | } | |
1176 | ||
8feae131 | 1177 | vma->vm_region = region; |
1da177e4 | 1178 | |
645d83c5 | 1179 | /* set up the mapping |
b4caecd4 | 1180 | * - the region is filled in if NOMMU_MAP_DIRECT is still set |
645d83c5 | 1181 | */ |
1da177e4 | 1182 | if (file && vma->vm_flags & VM_SHARED) |
8feae131 | 1183 | ret = do_mmap_shared_file(vma); |
1da177e4 | 1184 | else |
645d83c5 | 1185 | ret = do_mmap_private(vma, region, len, capabilities); |
1da177e4 | 1186 | if (ret < 0) |
645d83c5 DH |
1187 | goto error_just_free; |
1188 | add_nommu_region(region); | |
8feae131 | 1189 | |
ea637639 | 1190 | /* clear anonymous mappings that don't ask for uninitialized data */ |
0bf5f949 CH |
1191 | if (!vma->vm_file && |
1192 | (!IS_ENABLED(CONFIG_MMAP_ALLOW_UNINITIALIZED) || | |
1193 | !(flags & MAP_UNINITIALIZED))) | |
ea637639 JZ |
1194 | memset((void *)region->vm_start, 0, |
1195 | region->vm_end - region->vm_start); | |
1196 | ||
1da177e4 | 1197 | /* okay... we have a mapping; now we have to register it */ |
8feae131 | 1198 | result = vma->vm_start; |
1da177e4 | 1199 | |
1da177e4 LT |
1200 | current->mm->total_vm += len >> PAGE_SHIFT; |
1201 | ||
8feae131 | 1202 | share: |
07f1bc5a | 1203 | BUG_ON(!vma->vm_region); |
b5df0922 LH |
1204 | vma_iter_config(&vmi, vma->vm_start, vma->vm_end); |
1205 | if (vma_iter_prealloc(&vmi, vma)) | |
1206 | goto error_just_free; | |
1207 | ||
07f1bc5a LH |
1208 | setup_vma_to_mm(vma, current->mm); |
1209 | current->mm->map_count++; | |
1210 | /* add the VMA to the tree */ | |
1211 | vma_iter_store(&vmi, vma); | |
1da177e4 | 1212 | |
cfe79c00 MF |
1213 | /* we flush the region from the icache only when the first executable |
1214 | * mapping of it is made */ | |
1215 | if (vma->vm_flags & VM_EXEC && !region->vm_icache_flushed) { | |
a75a2df6 | 1216 | flush_icache_user_range(region->vm_start, region->vm_end); |
cfe79c00 MF |
1217 | region->vm_icache_flushed = true; |
1218 | } | |
1da177e4 | 1219 | |
cfe79c00 | 1220 | up_write(&nommu_region_sem); |
1da177e4 | 1221 | |
8feae131 | 1222 | return result; |
1da177e4 | 1223 | |
8feae131 DH |
1224 | error_just_free: |
1225 | up_write(&nommu_region_sem); | |
1226 | error: | |
47d9644d | 1227 | vma_iter_free(&vmi); |
89a86402 DH |
1228 | if (region->vm_file) |
1229 | fput(region->vm_file); | |
8feae131 | 1230 | kmem_cache_free(vm_region_jar, region); |
89a86402 DH |
1231 | if (vma->vm_file) |
1232 | fput(vma->vm_file); | |
3928d4f5 | 1233 | vm_area_free(vma); |
8feae131 DH |
1234 | return ret; |
1235 | ||
1236 | sharing_violation: | |
1237 | up_write(&nommu_region_sem); | |
22cc877b | 1238 | pr_warn("Attempt to share mismatched mappings\n"); |
8feae131 DH |
1239 | ret = -EINVAL; |
1240 | goto error; | |
1da177e4 | 1241 | |
8feae131 DH |
1242 | error_getting_vma: |
1243 | kmem_cache_free(vm_region_jar, region); | |
22cc877b LR |
1244 | pr_warn("Allocation of vma for %lu byte allocation from process %d failed\n", |
1245 | len, current->pid); | |
1279aa06 | 1246 | show_mem(); |
1da177e4 LT |
1247 | return -ENOMEM; |
1248 | ||
8feae131 | 1249 | error_getting_region: |
22cc877b LR |
1250 | pr_warn("Allocation of vm region for %lu byte allocation from process %d failed\n", |
1251 | len, current->pid); | |
1279aa06 | 1252 | show_mem(); |
1da177e4 LT |
1253 | return -ENOMEM; |
1254 | } | |
6be5ceb0 | 1255 | |
a90f590a DB |
1256 | unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len, |
1257 | unsigned long prot, unsigned long flags, | |
1258 | unsigned long fd, unsigned long pgoff) | |
66f0dc48 HD |
1259 | { |
1260 | struct file *file = NULL; | |
1261 | unsigned long retval = -EBADF; | |
1262 | ||
120a795d | 1263 | audit_mmap_fd(fd, flags); |
66f0dc48 HD |
1264 | if (!(flags & MAP_ANONYMOUS)) { |
1265 | file = fget(fd); | |
1266 | if (!file) | |
1267 | goto out; | |
1268 | } | |
1269 | ||
ad1ed293 | 1270 | retval = vm_mmap_pgoff(file, addr, len, prot, flags, pgoff); |
66f0dc48 HD |
1271 | |
1272 | if (file) | |
1273 | fput(file); | |
1274 | out: | |
1275 | return retval; | |
1276 | } | |
1277 | ||
a90f590a DB |
1278 | SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len, |
1279 | unsigned long, prot, unsigned long, flags, | |
1280 | unsigned long, fd, unsigned long, pgoff) | |
1281 | { | |
1282 | return ksys_mmap_pgoff(addr, len, prot, flags, fd, pgoff); | |
1283 | } | |
1284 | ||
a4679373 CH |
1285 | #ifdef __ARCH_WANT_SYS_OLD_MMAP |
1286 | struct mmap_arg_struct { | |
1287 | unsigned long addr; | |
1288 | unsigned long len; | |
1289 | unsigned long prot; | |
1290 | unsigned long flags; | |
1291 | unsigned long fd; | |
1292 | unsigned long offset; | |
1293 | }; | |
1294 | ||
1295 | SYSCALL_DEFINE1(old_mmap, struct mmap_arg_struct __user *, arg) | |
1296 | { | |
1297 | struct mmap_arg_struct a; | |
1298 | ||
1299 | if (copy_from_user(&a, arg, sizeof(a))) | |
1300 | return -EFAULT; | |
1824cb75 | 1301 | if (offset_in_page(a.offset)) |
a4679373 CH |
1302 | return -EINVAL; |
1303 | ||
a90f590a DB |
1304 | return ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, |
1305 | a.offset >> PAGE_SHIFT); | |
a4679373 CH |
1306 | } |
1307 | #endif /* __ARCH_WANT_SYS_OLD_MMAP */ | |
1308 | ||
1da177e4 | 1309 | /* |
8feae131 DH |
1310 | * split a vma into two pieces at address 'addr', a new vma is allocated either |
1311 | * for the first part or the tail. | |
1da177e4 | 1312 | */ |
adb20b0c LS |
1313 | static int split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma, |
1314 | unsigned long addr, int new_below) | |
1da177e4 | 1315 | { |
8feae131 DH |
1316 | struct vm_area_struct *new; |
1317 | struct vm_region *region; | |
1318 | unsigned long npages; | |
9760ebff | 1319 | struct mm_struct *mm; |
1da177e4 | 1320 | |
779c1023 DH |
1321 | /* we're only permitted to split anonymous regions (these should have |
1322 | * only a single usage on the region) */ | |
1323 | if (vma->vm_file) | |
8feae131 | 1324 | return -ENOMEM; |
1da177e4 | 1325 | |
9760ebff | 1326 | mm = vma->vm_mm; |
8feae131 DH |
1327 | if (mm->map_count >= sysctl_max_map_count) |
1328 | return -ENOMEM; | |
1da177e4 | 1329 | |
8feae131 DH |
1330 | region = kmem_cache_alloc(vm_region_jar, GFP_KERNEL); |
1331 | if (!region) | |
1332 | return -ENOMEM; | |
1da177e4 | 1333 | |
3928d4f5 | 1334 | new = vm_area_dup(vma); |
8220543d MWO |
1335 | if (!new) |
1336 | goto err_vma_dup; | |
1337 | ||
8feae131 | 1338 | /* most fields are the same, copy all, and then fixup */ |
8feae131 DH |
1339 | *region = *vma->vm_region; |
1340 | new->vm_region = region; | |
1341 | ||
1342 | npages = (addr - vma->vm_start) >> PAGE_SHIFT; | |
1343 | ||
1344 | if (new_below) { | |
dd8632a1 | 1345 | region->vm_top = region->vm_end = new->vm_end = addr; |
8feae131 DH |
1346 | } else { |
1347 | region->vm_start = new->vm_start = addr; | |
1348 | region->vm_pgoff = new->vm_pgoff += npages; | |
1da177e4 | 1349 | } |
8feae131 | 1350 | |
b5df0922 LH |
1351 | vma_iter_config(vmi, new->vm_start, new->vm_end); |
1352 | if (vma_iter_prealloc(vmi, vma)) { | |
1353 | pr_warn("Allocation of vma tree for process %d failed\n", | |
1354 | current->pid); | |
1355 | goto err_vmi_preallocate; | |
1356 | } | |
1357 | ||
8feae131 DH |
1358 | if (new->vm_ops && new->vm_ops->open) |
1359 | new->vm_ops->open(new); | |
1360 | ||
8feae131 DH |
1361 | down_write(&nommu_region_sem); |
1362 | delete_nommu_region(vma->vm_region); | |
1363 | if (new_below) { | |
1364 | vma->vm_region->vm_start = vma->vm_start = addr; | |
1365 | vma->vm_region->vm_pgoff = vma->vm_pgoff += npages; | |
1366 | } else { | |
1367 | vma->vm_region->vm_end = vma->vm_end = addr; | |
dd8632a1 | 1368 | vma->vm_region->vm_top = addr; |
8feae131 DH |
1369 | } |
1370 | add_nommu_region(vma->vm_region); | |
1371 | add_nommu_region(new->vm_region); | |
1372 | up_write(&nommu_region_sem); | |
8220543d MWO |
1373 | |
1374 | setup_vma_to_mm(vma, mm); | |
1375 | setup_vma_to_mm(new, mm); | |
47d9644d | 1376 | vma_iter_store(vmi, new); |
fd9edbdb | 1377 | mm->map_count++; |
8feae131 | 1378 | return 0; |
8220543d | 1379 | |
47d9644d | 1380 | err_vmi_preallocate: |
8220543d MWO |
1381 | vm_area_free(new); |
1382 | err_vma_dup: | |
1383 | kmem_cache_free(vm_region_jar, region); | |
1384 | return -ENOMEM; | |
1da177e4 LT |
1385 | } |
1386 | ||
3034097a | 1387 | /* |
8feae131 DH |
1388 | * shrink a VMA by removing the specified chunk from either the beginning or |
1389 | * the end | |
3034097a | 1390 | */ |
07f1bc5a | 1391 | static int vmi_shrink_vma(struct vma_iterator *vmi, |
8feae131 DH |
1392 | struct vm_area_struct *vma, |
1393 | unsigned long from, unsigned long to) | |
1da177e4 | 1394 | { |
8feae131 | 1395 | struct vm_region *region; |
1da177e4 | 1396 | |
8feae131 DH |
1397 | /* adjust the VMA's pointers, which may reposition it in the MM's tree |
1398 | * and list */ | |
07f1bc5a | 1399 | if (from > vma->vm_start) { |
f72cf24a LH |
1400 | if (vma_iter_clear_gfp(vmi, from, vma->vm_end, GFP_KERNEL)) |
1401 | return -ENOMEM; | |
8feae131 | 1402 | vma->vm_end = from; |
07f1bc5a | 1403 | } else { |
f72cf24a LH |
1404 | if (vma_iter_clear_gfp(vmi, vma->vm_start, to, GFP_KERNEL)) |
1405 | return -ENOMEM; | |
8feae131 | 1406 | vma->vm_start = to; |
07f1bc5a | 1407 | } |
1da177e4 | 1408 | |
8feae131 DH |
1409 | /* cut the backing region down to size */ |
1410 | region = vma->vm_region; | |
1e2ae599 | 1411 | BUG_ON(region->vm_usage != 1); |
8feae131 DH |
1412 | |
1413 | down_write(&nommu_region_sem); | |
1414 | delete_nommu_region(region); | |
dd8632a1 PM |
1415 | if (from > region->vm_start) { |
1416 | to = region->vm_top; | |
1417 | region->vm_top = region->vm_end = from; | |
1418 | } else { | |
8feae131 | 1419 | region->vm_start = to; |
dd8632a1 | 1420 | } |
8feae131 DH |
1421 | add_nommu_region(region); |
1422 | up_write(&nommu_region_sem); | |
1423 | ||
1424 | free_page_series(from, to); | |
1425 | return 0; | |
1426 | } | |
1da177e4 | 1427 | |
8feae131 DH |
1428 | /* |
1429 | * release a mapping | |
1430 | * - under NOMMU conditions the chunk to be unmapped must be backed by a single | |
1431 | * VMA, though it need not cover the whole VMA | |
1432 | */ | |
897ab3e0 | 1433 | int do_munmap(struct mm_struct *mm, unsigned long start, size_t len, struct list_head *uf) |
8feae131 | 1434 | { |
47d9644d | 1435 | VMA_ITERATOR(vmi, mm, start); |
8feae131 | 1436 | struct vm_area_struct *vma; |
f67d9b15 | 1437 | unsigned long end; |
8220543d | 1438 | int ret = 0; |
1da177e4 | 1439 | |
f67d9b15 | 1440 | len = PAGE_ALIGN(len); |
8feae131 DH |
1441 | if (len == 0) |
1442 | return -EINVAL; | |
365e9c87 | 1443 | |
f67d9b15 BL |
1444 | end = start + len; |
1445 | ||
8feae131 | 1446 | /* find the first potentially overlapping VMA */ |
47d9644d | 1447 | vma = vma_find(&vmi, end); |
8feae131 | 1448 | if (!vma) { |
ac714904 | 1449 | static int limit; |
33e5d769 | 1450 | if (limit < 5) { |
22cc877b LR |
1451 | pr_warn("munmap of memory not mmapped by process %d (%s): 0x%lx-0x%lx\n", |
1452 | current->pid, current->comm, | |
1453 | start, start + len - 1); | |
33e5d769 DH |
1454 | limit++; |
1455 | } | |
8feae131 DH |
1456 | return -EINVAL; |
1457 | } | |
1da177e4 | 1458 | |
8feae131 DH |
1459 | /* we're allowed to split an anonymous VMA but not a file-backed one */ |
1460 | if (vma->vm_file) { | |
1461 | do { | |
22cc877b | 1462 | if (start > vma->vm_start) |
8feae131 | 1463 | return -EINVAL; |
8feae131 DH |
1464 | if (end == vma->vm_end) |
1465 | goto erase_whole_vma; | |
47d9644d | 1466 | vma = vma_find(&vmi, end); |
d75a310c | 1467 | } while (vma); |
8feae131 DH |
1468 | return -EINVAL; |
1469 | } else { | |
1470 | /* the chunk must be a subset of the VMA found */ | |
1471 | if (start == vma->vm_start && end == vma->vm_end) | |
1472 | goto erase_whole_vma; | |
22cc877b | 1473 | if (start < vma->vm_start || end > vma->vm_end) |
8feae131 | 1474 | return -EINVAL; |
1824cb75 | 1475 | if (offset_in_page(start)) |
8feae131 | 1476 | return -EINVAL; |
1824cb75 | 1477 | if (end != vma->vm_end && offset_in_page(end)) |
8feae131 | 1478 | return -EINVAL; |
8feae131 | 1479 | if (start != vma->vm_start && end != vma->vm_end) { |
9760ebff | 1480 | ret = split_vma(&vmi, vma, start, 1); |
22cc877b | 1481 | if (ret < 0) |
8feae131 | 1482 | return ret; |
8feae131 | 1483 | } |
07f1bc5a | 1484 | return vmi_shrink_vma(&vmi, vma, start, end); |
8feae131 | 1485 | } |
1da177e4 | 1486 | |
8feae131 | 1487 | erase_whole_vma: |
8220543d MWO |
1488 | if (delete_vma_from_mm(vma)) |
1489 | ret = -ENOMEM; | |
80be727e LH |
1490 | else |
1491 | delete_vma(mm, vma); | |
8220543d | 1492 | return ret; |
1da177e4 LT |
1493 | } |
1494 | ||
bfce281c | 1495 | int vm_munmap(unsigned long addr, size_t len) |
3034097a | 1496 | { |
bfce281c | 1497 | struct mm_struct *mm = current->mm; |
3034097a | 1498 | int ret; |
3034097a | 1499 | |
d8ed45c5 | 1500 | mmap_write_lock(mm); |
897ab3e0 | 1501 | ret = do_munmap(mm, addr, len, NULL); |
d8ed45c5 | 1502 | mmap_write_unlock(mm); |
3034097a DH |
1503 | return ret; |
1504 | } | |
a46ef99d LT |
1505 | EXPORT_SYMBOL(vm_munmap); |
1506 | ||
1507 | SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len) | |
1508 | { | |
bfce281c | 1509 | return vm_munmap(addr, len); |
a46ef99d | 1510 | } |
3034097a DH |
1511 | |
1512 | /* | |
8feae131 | 1513 | * release all the mappings made in a process's VM space |
3034097a | 1514 | */ |
8feae131 | 1515 | void exit_mmap(struct mm_struct *mm) |
1da177e4 | 1516 | { |
8220543d | 1517 | VMA_ITERATOR(vmi, mm, 0); |
8feae131 | 1518 | struct vm_area_struct *vma; |
1da177e4 | 1519 | |
8feae131 DH |
1520 | if (!mm) |
1521 | return; | |
1da177e4 | 1522 | |
8feae131 | 1523 | mm->total_vm = 0; |
1da177e4 | 1524 | |
8220543d MWO |
1525 | /* |
1526 | * Lock the mm to avoid assert complaining even though this is the only | |
1527 | * user of the mm | |
1528 | */ | |
1529 | mmap_write_lock(mm); | |
1530 | for_each_vma(vmi, vma) { | |
1531 | cleanup_vma_from_mm(vma); | |
8feae131 | 1532 | delete_vma(mm, vma); |
04c34961 | 1533 | cond_resched(); |
1da177e4 | 1534 | } |
524e00b3 | 1535 | __mt_destroy(&mm->mm_mt); |
8220543d | 1536 | mmap_write_unlock(mm); |
1da177e4 LT |
1537 | } |
1538 | ||
1da177e4 | 1539 | /* |
6fa5f80b DH |
1540 | * expand (or shrink) an existing mapping, potentially moving it at the same |
1541 | * time (controlled by the MREMAP_MAYMOVE flag and available VM space) | |
1da177e4 | 1542 | * |
6fa5f80b | 1543 | * under NOMMU conditions, we only permit changing a mapping's size, and only |
8feae131 DH |
1544 | * as long as it stays within the region allocated by do_mmap_private() and the |
1545 | * block is not shareable | |
1da177e4 | 1546 | * |
6fa5f80b | 1547 | * MREMAP_FIXED is not supported under NOMMU conditions |
1da177e4 | 1548 | */ |
4b377bab | 1549 | static unsigned long do_mremap(unsigned long addr, |
1da177e4 LT |
1550 | unsigned long old_len, unsigned long new_len, |
1551 | unsigned long flags, unsigned long new_addr) | |
1552 | { | |
6fa5f80b | 1553 | struct vm_area_struct *vma; |
1da177e4 LT |
1554 | |
1555 | /* insanity checks first */ | |
f67d9b15 BL |
1556 | old_len = PAGE_ALIGN(old_len); |
1557 | new_len = PAGE_ALIGN(new_len); | |
8feae131 | 1558 | if (old_len == 0 || new_len == 0) |
1da177e4 LT |
1559 | return (unsigned long) -EINVAL; |
1560 | ||
1824cb75 | 1561 | if (offset_in_page(addr)) |
8feae131 DH |
1562 | return -EINVAL; |
1563 | ||
1da177e4 LT |
1564 | if (flags & MREMAP_FIXED && new_addr != addr) |
1565 | return (unsigned long) -EINVAL; | |
1566 | ||
8feae131 | 1567 | vma = find_vma_exact(current->mm, addr, old_len); |
6fa5f80b DH |
1568 | if (!vma) |
1569 | return (unsigned long) -EINVAL; | |
1da177e4 | 1570 | |
6fa5f80b | 1571 | if (vma->vm_end != vma->vm_start + old_len) |
1da177e4 LT |
1572 | return (unsigned long) -EFAULT; |
1573 | ||
fc4f4be9 | 1574 | if (is_nommu_shared_mapping(vma->vm_flags)) |
1da177e4 LT |
1575 | return (unsigned long) -EPERM; |
1576 | ||
8feae131 | 1577 | if (new_len > vma->vm_region->vm_end - vma->vm_region->vm_start) |
1da177e4 LT |
1578 | return (unsigned long) -ENOMEM; |
1579 | ||
1580 | /* all checks complete - do it */ | |
6fa5f80b | 1581 | vma->vm_end = vma->vm_start + new_len; |
6fa5f80b DH |
1582 | return vma->vm_start; |
1583 | } | |
1584 | ||
6a6160a7 HC |
1585 | SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, |
1586 | unsigned long, new_len, unsigned long, flags, | |
1587 | unsigned long, new_addr) | |
6fa5f80b DH |
1588 | { |
1589 | unsigned long ret; | |
1590 | ||
d8ed45c5 | 1591 | mmap_write_lock(current->mm); |
6fa5f80b | 1592 | ret = do_mremap(addr, old_len, new_len, flags, new_addr); |
d8ed45c5 | 1593 | mmap_write_unlock(current->mm); |
6fa5f80b | 1594 | return ret; |
1da177e4 LT |
1595 | } |
1596 | ||
df06b37f KB |
1597 | struct page *follow_page(struct vm_area_struct *vma, unsigned long address, |
1598 | unsigned int foll_flags) | |
1da177e4 LT |
1599 | { |
1600 | return NULL; | |
1601 | } | |
1602 | ||
8f3b1327 BL |
1603 | int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, |
1604 | unsigned long pfn, unsigned long size, pgprot_t prot) | |
1da177e4 | 1605 | { |
8f3b1327 BL |
1606 | if (addr != (pfn << PAGE_SHIFT)) |
1607 | return -EINVAL; | |
1608 | ||
1c71222e | 1609 | vm_flags_set(vma, VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP); |
66aa2b4b | 1610 | return 0; |
1da177e4 | 1611 | } |
22c4af40 | 1612 | EXPORT_SYMBOL(remap_pfn_range); |
1da177e4 | 1613 | |
3c0b9de6 LT |
1614 | int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len) |
1615 | { | |
1616 | unsigned long pfn = start >> PAGE_SHIFT; | |
1617 | unsigned long vm_len = vma->vm_end - vma->vm_start; | |
1618 | ||
1619 | pfn += vma->vm_pgoff; | |
1620 | return io_remap_pfn_range(vma, vma->vm_start, pfn, vm_len, vma->vm_page_prot); | |
1621 | } | |
1622 | EXPORT_SYMBOL(vm_iomap_memory); | |
1623 | ||
f905bc44 PM |
1624 | int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, |
1625 | unsigned long pgoff) | |
1626 | { | |
1627 | unsigned int size = vma->vm_end - vma->vm_start; | |
1628 | ||
1629 | if (!(vma->vm_flags & VM_USERMAP)) | |
1630 | return -EINVAL; | |
1631 | ||
1632 | vma->vm_start = (unsigned long)(addr + (pgoff << PAGE_SHIFT)); | |
1633 | vma->vm_end = vma->vm_start + size; | |
1634 | ||
1635 | return 0; | |
1636 | } | |
1637 | EXPORT_SYMBOL(remap_vmalloc_range); | |
1638 | ||
2bcd6454 | 1639 | vm_fault_t filemap_fault(struct vm_fault *vmf) |
b0e15190 DH |
1640 | { |
1641 | BUG(); | |
d0217ac0 | 1642 | return 0; |
b0e15190 | 1643 | } |
b5073173 | 1644 | EXPORT_SYMBOL(filemap_fault); |
0ec76a11 | 1645 | |
3f98a28c | 1646 | vm_fault_t filemap_map_pages(struct vm_fault *vmf, |
bae473a4 | 1647 | pgoff_t start_pgoff, pgoff_t end_pgoff) |
f1820361 KS |
1648 | { |
1649 | BUG(); | |
3f98a28c | 1650 | return 0; |
f1820361 KS |
1651 | } |
1652 | EXPORT_SYMBOL(filemap_map_pages); | |
1653 | ||
c43cfa42 LS |
1654 | static int __access_remote_vm(struct mm_struct *mm, unsigned long addr, |
1655 | void *buf, int len, unsigned int gup_flags) | |
0ec76a11 | 1656 | { |
0ec76a11 | 1657 | struct vm_area_struct *vma; |
442486ec | 1658 | int write = gup_flags & FOLL_WRITE; |
0ec76a11 | 1659 | |
d8ed45c5 | 1660 | if (mmap_read_lock_killable(mm)) |
1e426fe2 | 1661 | return 0; |
0ec76a11 DH |
1662 | |
1663 | /* the access must start within one of the target process's mappings */ | |
0159b141 DH |
1664 | vma = find_vma(mm, addr); |
1665 | if (vma) { | |
0ec76a11 DH |
1666 | /* don't overrun this mapping */ |
1667 | if (addr + len >= vma->vm_end) | |
1668 | len = vma->vm_end - addr; | |
1669 | ||
1670 | /* only read or write mappings where it is permitted */ | |
d00c7b99 | 1671 | if (write && vma->vm_flags & VM_MAYWRITE) |
7959722b JZ |
1672 | copy_to_user_page(vma, NULL, addr, |
1673 | (void *) addr, buf, len); | |
d00c7b99 | 1674 | else if (!write && vma->vm_flags & VM_MAYREAD) |
7959722b JZ |
1675 | copy_from_user_page(vma, NULL, addr, |
1676 | buf, (void *) addr, len); | |
0ec76a11 DH |
1677 | else |
1678 | len = 0; | |
1679 | } else { | |
1680 | len = 0; | |
1681 | } | |
1682 | ||
d8ed45c5 | 1683 | mmap_read_unlock(mm); |
f55f199b MF |
1684 | |
1685 | return len; | |
1686 | } | |
1687 | ||
1688 | /** | |
b7701a5f | 1689 | * access_remote_vm - access another process' address space |
f55f199b MF |
1690 | * @mm: the mm_struct of the target address space |
1691 | * @addr: start address to access | |
1692 | * @buf: source or destination buffer | |
1693 | * @len: number of bytes to transfer | |
6347e8d5 | 1694 | * @gup_flags: flags modifying lookup behaviour |
f55f199b MF |
1695 | * |
1696 | * The caller must hold a reference on @mm. | |
1697 | */ | |
1698 | int access_remote_vm(struct mm_struct *mm, unsigned long addr, | |
6347e8d5 | 1699 | void *buf, int len, unsigned int gup_flags) |
f55f199b | 1700 | { |
d3f5ffca | 1701 | return __access_remote_vm(mm, addr, buf, len, gup_flags); |
f55f199b MF |
1702 | } |
1703 | ||
1704 | /* | |
1705 | * Access another process' address space. | |
1706 | * - source/target buffer must be kernel space | |
1707 | */ | |
f307ab6d LS |
1708 | int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, |
1709 | unsigned int gup_flags) | |
f55f199b MF |
1710 | { |
1711 | struct mm_struct *mm; | |
1712 | ||
1713 | if (addr + len < addr) | |
1714 | return 0; | |
1715 | ||
1716 | mm = get_task_mm(tsk); | |
1717 | if (!mm) | |
1718 | return 0; | |
1719 | ||
d3f5ffca | 1720 | len = __access_remote_vm(mm, addr, buf, len, gup_flags); |
f55f199b | 1721 | |
0ec76a11 DH |
1722 | mmput(mm); |
1723 | return len; | |
1724 | } | |
fcd35857 | 1725 | EXPORT_SYMBOL_GPL(access_process_vm); |
7e660872 DH |
1726 | |
1727 | /** | |
1728 | * nommu_shrink_inode_mappings - Shrink the shared mappings on an inode | |
1729 | * @inode: The inode to check | |
1730 | * @size: The current filesize of the inode | |
1731 | * @newsize: The proposed filesize of the inode | |
1732 | * | |
1733 | * Check the shared mappings on an inode on behalf of a shrinking truncate to | |
c08b342c RD |
1734 | * make sure that any outstanding VMAs aren't broken and then shrink the |
1735 | * vm_regions that extend beyond so that do_mmap() doesn't | |
7e660872 DH |
1736 | * automatically grant mappings that are too large. |
1737 | */ | |
1738 | int nommu_shrink_inode_mappings(struct inode *inode, size_t size, | |
1739 | size_t newsize) | |
1740 | { | |
1741 | struct vm_area_struct *vma; | |
7e660872 DH |
1742 | struct vm_region *region; |
1743 | pgoff_t low, high; | |
1744 | size_t r_size, r_top; | |
1745 | ||
1746 | low = newsize >> PAGE_SHIFT; | |
1747 | high = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
1748 | ||
1749 | down_write(&nommu_region_sem); | |
1acf2e04 | 1750 | i_mmap_lock_read(inode->i_mapping); |
7e660872 DH |
1751 | |
1752 | /* search for VMAs that fall within the dead zone */ | |
6b2dbba8 | 1753 | vma_interval_tree_foreach(vma, &inode->i_mapping->i_mmap, low, high) { |
7e660872 DH |
1754 | /* found one - only interested if it's shared out of the page |
1755 | * cache */ | |
1756 | if (vma->vm_flags & VM_SHARED) { | |
1acf2e04 | 1757 | i_mmap_unlock_read(inode->i_mapping); |
7e660872 DH |
1758 | up_write(&nommu_region_sem); |
1759 | return -ETXTBSY; /* not quite true, but near enough */ | |
1760 | } | |
1761 | } | |
1762 | ||
1763 | /* reduce any regions that overlap the dead zone - if in existence, | |
1764 | * these will be pointed to by VMAs that don't overlap the dead zone | |
1765 | * | |
1766 | * we don't check for any regions that start beyond the EOF as there | |
1767 | * shouldn't be any | |
1768 | */ | |
1acf2e04 | 1769 | vma_interval_tree_foreach(vma, &inode->i_mapping->i_mmap, 0, ULONG_MAX) { |
7e660872 DH |
1770 | if (!(vma->vm_flags & VM_SHARED)) |
1771 | continue; | |
1772 | ||
1773 | region = vma->vm_region; | |
1774 | r_size = region->vm_top - region->vm_start; | |
1775 | r_top = (region->vm_pgoff << PAGE_SHIFT) + r_size; | |
1776 | ||
1777 | if (r_top > newsize) { | |
1778 | region->vm_top -= r_top - newsize; | |
1779 | if (region->vm_end > region->vm_top) | |
1780 | region->vm_end = region->vm_top; | |
1781 | } | |
1782 | } | |
1783 | ||
1acf2e04 | 1784 | i_mmap_unlock_read(inode->i_mapping); |
7e660872 DH |
1785 | up_write(&nommu_region_sem); |
1786 | return 0; | |
1787 | } | |
c9b1d098 AS |
1788 | |
1789 | /* | |
1790 | * Initialise sysctl_user_reserve_kbytes. | |
1791 | * | |
1792 | * This is intended to prevent a user from starting a single memory hogging | |
1793 | * process, such that they cannot recover (kill the hog) in OVERCOMMIT_NEVER | |
1794 | * mode. | |
1795 | * | |
1796 | * The default value is min(3% of free memory, 128MB) | |
1797 | * 128MB is enough to recover with sshd/login, bash, and top/kill. | |
1798 | */ | |
1799 | static int __meminit init_user_reserve(void) | |
1800 | { | |
1801 | unsigned long free_kbytes; | |
1802 | ||
d5a6474d | 1803 | free_kbytes = K(global_zone_page_state(NR_FREE_PAGES)); |
c9b1d098 AS |
1804 | |
1805 | sysctl_user_reserve_kbytes = min(free_kbytes / 32, 1UL << 17); | |
1806 | return 0; | |
1807 | } | |
a4bc6fc7 | 1808 | subsys_initcall(init_user_reserve); |
4eeab4f5 AS |
1809 | |
1810 | /* | |
1811 | * Initialise sysctl_admin_reserve_kbytes. | |
1812 | * | |
1813 | * The purpose of sysctl_admin_reserve_kbytes is to allow the sys admin | |
1814 | * to log in and kill a memory hogging process. | |
1815 | * | |
1816 | * Systems with more than 256MB will reserve 8MB, enough to recover | |
1817 | * with sshd, bash, and top in OVERCOMMIT_GUESS. Smaller systems will | |
1818 | * only reserve 3% of free pages by default. | |
1819 | */ | |
1820 | static int __meminit init_admin_reserve(void) | |
1821 | { | |
1822 | unsigned long free_kbytes; | |
1823 | ||
d5a6474d | 1824 | free_kbytes = K(global_zone_page_state(NR_FREE_PAGES)); |
4eeab4f5 AS |
1825 | |
1826 | sysctl_admin_reserve_kbytes = min(free_kbytes / 32, 1UL << 13); | |
1827 | return 0; | |
1828 | } | |
a4bc6fc7 | 1829 | subsys_initcall(init_admin_reserve); |