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16
17#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18
19#include <linux/export.h>
20#include <linux/mm.h>
21#include <linux/sched/mm.h>
22#include <linux/vmacache.h>
23#include <linux/mman.h>
24#include <linux/swap.h>
25#include <linux/file.h>
26#include <linux/highmem.h>
27#include <linux/pagemap.h>
28#include <linux/slab.h>
29#include <linux/vmalloc.h>
30#include <linux/blkdev.h>
31#include <linux/backing-dev.h>
32#include <linux/compiler.h>
33#include <linux/mount.h>
34#include <linux/personality.h>
35#include <linux/security.h>
36#include <linux/syscalls.h>
37#include <linux/audit.h>
38#include <linux/printk.h>
39
40#include <linux/uaccess.h>
41#include <asm/tlb.h>
42#include <asm/tlbflush.h>
43#include <asm/mmu_context.h>
44#include "internal.h"
45
46void *high_memory;
47EXPORT_SYMBOL(high_memory);
48struct page *mem_map;
49unsigned long max_mapnr;
50EXPORT_SYMBOL(max_mapnr);
51unsigned long highest_memmap_pfn;
52int sysctl_nr_trim_pages = CONFIG_NOMMU_INITIAL_TRIM_EXCESS;
53int heap_stack_gap = 0;
54
55atomic_long_t mmap_pages_allocated;
56
57EXPORT_SYMBOL(mem_map);
58
59
60static struct kmem_cache *vm_region_jar;
61struct rb_root nommu_region_tree = RB_ROOT;
62DECLARE_RWSEM(nommu_region_sem);
63
64const struct vm_operations_struct generic_file_vm_ops = {
65};
66
67
68
69
70
71
72
73unsigned int kobjsize(const void *objp)
74{
75 struct page *page;
76
77
78
79
80
81 if (!objp || !virt_addr_valid(objp))
82 return 0;
83
84 page = virt_to_head_page(objp);
85
86
87
88
89
90 if (PageSlab(page))
91 return ksize(objp);
92
93
94
95
96
97
98
99 if (!PageCompound(page)) {
100 struct vm_area_struct *vma;
101
102 vma = find_vma(current->mm, (unsigned long)objp);
103 if (vma)
104 return vma->vm_end - vma->vm_start;
105 }
106
107
108
109
110
111 return PAGE_SIZE << compound_order(page);
112}
113
114static long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
115 unsigned long start, unsigned long nr_pages,
116 unsigned int foll_flags, struct page **pages,
117 struct vm_area_struct **vmas, int *nonblocking)
118{
119 struct vm_area_struct *vma;
120 unsigned long vm_flags;
121 int i;
122
123
124
125
126 vm_flags = (foll_flags & FOLL_WRITE) ?
127 (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD);
128 vm_flags &= (foll_flags & FOLL_FORCE) ?
129 (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE);
130
131 for (i = 0; i < nr_pages; i++) {
132 vma = find_vma(mm, start);
133 if (!vma)
134 goto finish_or_fault;
135
136
137 if ((vma->vm_flags & (VM_IO | VM_PFNMAP)) ||
138 !(vm_flags & vma->vm_flags))
139 goto finish_or_fault;
140
141 if (pages) {
142 pages[i] = virt_to_page(start);
143 if (pages[i])
144 get_page(pages[i]);
145 }
146 if (vmas)
147 vmas[i] = vma;
148 start = (start + PAGE_SIZE) & PAGE_MASK;
149 }
150
151 return i;
152
153finish_or_fault:
154 return i ? : -EFAULT;
155}
156
157
158
159
160
161
162
163
164long get_user_pages(unsigned long start, unsigned long nr_pages,
165 unsigned int gup_flags, struct page **pages,
166 struct vm_area_struct **vmas)
167{
168 return __get_user_pages(current, current->mm, start, nr_pages,
169 gup_flags, pages, vmas, NULL);
170}
171EXPORT_SYMBOL(get_user_pages);
172
173long get_user_pages_locked(unsigned long start, unsigned long nr_pages,
174 unsigned int gup_flags, struct page **pages,
175 int *locked)
176{
177 return get_user_pages(start, nr_pages, gup_flags, pages, NULL);
178}
179EXPORT_SYMBOL(get_user_pages_locked);
180
181static long __get_user_pages_unlocked(struct task_struct *tsk,
182 struct mm_struct *mm, unsigned long start,
183 unsigned long nr_pages, struct page **pages,
184 unsigned int gup_flags)
185{
186 long ret;
187 down_read(&mm->mmap_sem);
188 ret = __get_user_pages(tsk, mm, start, nr_pages, gup_flags, pages,
189 NULL, NULL);
190 up_read(&mm->mmap_sem);
191 return ret;
192}
193
194long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages,
195 struct page **pages, unsigned int gup_flags)
196{
197 return __get_user_pages_unlocked(current, current->mm, start, nr_pages,
198 pages, gup_flags);
199}
200EXPORT_SYMBOL(get_user_pages_unlocked);
201
202
203
204
205
206
207
208
209
210
211
212int follow_pfn(struct vm_area_struct *vma, unsigned long address,
213 unsigned long *pfn)
214{
215 if (!(vma->vm_flags & (VM_IO | VM_PFNMAP)))
216 return -EINVAL;
217
218 *pfn = address >> PAGE_SHIFT;
219 return 0;
220}
221EXPORT_SYMBOL(follow_pfn);
222
223LIST_HEAD(vmap_area_list);
224
225void vfree(const void *addr)
226{
227 kfree(addr);
228}
229EXPORT_SYMBOL(vfree);
230
231void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
232{
233
234
235
236
237 return kmalloc(size, (gfp_mask | __GFP_COMP) & ~__GFP_HIGHMEM);
238}
239EXPORT_SYMBOL(__vmalloc);
240
241void *__vmalloc_node_flags(unsigned long size, int node, gfp_t flags)
242{
243 return __vmalloc(size, flags, PAGE_KERNEL);
244}
245
246void *vmalloc_user(unsigned long size)
247{
248 void *ret;
249
250 ret = __vmalloc(size, GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL);
251 if (ret) {
252 struct vm_area_struct *vma;
253
254 down_write(¤t->mm->mmap_sem);
255 vma = find_vma(current->mm, (unsigned long)ret);
256 if (vma)
257 vma->vm_flags |= VM_USERMAP;
258 up_write(¤t->mm->mmap_sem);
259 }
260
261 return ret;
262}
263EXPORT_SYMBOL(vmalloc_user);
264
265struct page *vmalloc_to_page(const void *addr)
266{
267 return virt_to_page(addr);
268}
269EXPORT_SYMBOL(vmalloc_to_page);
270
271unsigned long vmalloc_to_pfn(const void *addr)
272{
273 return page_to_pfn(virt_to_page(addr));
274}
275EXPORT_SYMBOL(vmalloc_to_pfn);
276
277long vread(char *buf, char *addr, unsigned long count)
278{
279
280 if ((unsigned long) buf + count < count)
281 count = -(unsigned long) buf;
282
283 memcpy(buf, addr, count);
284 return count;
285}
286
287long vwrite(char *buf, char *addr, unsigned long count)
288{
289
290 if ((unsigned long) addr + count < count)
291 count = -(unsigned long) addr;
292
293 memcpy(addr, buf, count);
294 return count;
295}
296
297
298
299
300
301
302
303
304
305
306
307
308void *vmalloc(unsigned long size)
309{
310 return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL);
311}
312EXPORT_SYMBOL(vmalloc);
313
314
315
316
317
318
319
320
321
322
323
324
325
326void *vzalloc(unsigned long size)
327{
328 return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
329 PAGE_KERNEL);
330}
331EXPORT_SYMBOL(vzalloc);
332
333
334
335
336
337
338
339
340
341
342
343
344void *vmalloc_node(unsigned long size, int node)
345{
346 return vmalloc(size);
347}
348EXPORT_SYMBOL(vmalloc_node);
349
350
351
352
353
354
355
356
357
358
359
360
361
362void *vzalloc_node(unsigned long size, int node)
363{
364 return vzalloc(size);
365}
366EXPORT_SYMBOL(vzalloc_node);
367
368
369
370
371
372
373
374
375
376
377
378
379
380void *vmalloc_exec(unsigned long size)
381{
382 return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC);
383}
384
385
386
387
388
389
390
391
392void *vmalloc_32(unsigned long size)
393{
394 return __vmalloc(size, GFP_KERNEL, PAGE_KERNEL);
395}
396EXPORT_SYMBOL(vmalloc_32);
397
398
399
400
401
402
403
404
405
406
407
408void *vmalloc_32_user(unsigned long size)
409{
410
411
412
413
414 return vmalloc_user(size);
415}
416EXPORT_SYMBOL(vmalloc_32_user);
417
418void *vmap(struct page **pages, unsigned int count, unsigned long flags, pgprot_t prot)
419{
420 BUG();
421 return NULL;
422}
423EXPORT_SYMBOL(vmap);
424
425void vunmap(const void *addr)
426{
427 BUG();
428}
429EXPORT_SYMBOL(vunmap);
430
431void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot)
432{
433 BUG();
434 return NULL;
435}
436EXPORT_SYMBOL(vm_map_ram);
437
438void vm_unmap_ram(const void *mem, unsigned int count)
439{
440 BUG();
441}
442EXPORT_SYMBOL(vm_unmap_ram);
443
444void vm_unmap_aliases(void)
445{
446}
447EXPORT_SYMBOL_GPL(vm_unmap_aliases);
448
449
450
451
452
453void __weak vmalloc_sync_all(void)
454{
455}
456
457struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes)
458{
459 BUG();
460 return NULL;
461}
462EXPORT_SYMBOL_GPL(alloc_vm_area);
463
464void free_vm_area(struct vm_struct *area)
465{
466 BUG();
467}
468EXPORT_SYMBOL_GPL(free_vm_area);
469
470int vm_insert_page(struct vm_area_struct *vma, unsigned long addr,
471 struct page *page)
472{
473 return -EINVAL;
474}
475EXPORT_SYMBOL(vm_insert_page);
476
477int vm_map_pages(struct vm_area_struct *vma, struct page **pages,
478 unsigned long num)
479{
480 return -EINVAL;
481}
482EXPORT_SYMBOL(vm_map_pages);
483
484int vm_map_pages_zero(struct vm_area_struct *vma, struct page **pages,
485 unsigned long num)
486{
487 return -EINVAL;
488}
489EXPORT_SYMBOL(vm_map_pages_zero);
490
491
492
493
494
495
496
497
498SYSCALL_DEFINE1(brk, unsigned long, brk)
499{
500 struct mm_struct *mm = current->mm;
501
502 if (brk < mm->start_brk || brk > mm->context.end_brk)
503 return mm->brk;
504
505 if (mm->brk == brk)
506 return mm->brk;
507
508
509
510
511 if (brk <= mm->brk) {
512 mm->brk = brk;
513 return brk;
514 }
515
516
517
518
519 flush_icache_range(mm->brk, brk);
520 return mm->brk = brk;
521}
522
523
524
525
526void __init mmap_init(void)
527{
528 int ret;
529
530 ret = percpu_counter_init(&vm_committed_as, 0, GFP_KERNEL);
531 VM_BUG_ON(ret);
532 vm_region_jar = KMEM_CACHE(vm_region, SLAB_PANIC|SLAB_ACCOUNT);
533}
534
535
536
537
538
539#ifdef CONFIG_DEBUG_NOMMU_REGIONS
540static noinline void validate_nommu_regions(void)
541{
542 struct vm_region *region, *last;
543 struct rb_node *p, *lastp;
544
545 lastp = rb_first(&nommu_region_tree);
546 if (!lastp)
547 return;
548
549 last = rb_entry(lastp, struct vm_region, vm_rb);
550 BUG_ON(last->vm_end <= last->vm_start);
551 BUG_ON(last->vm_top < last->vm_end);
552
553 while ((p = rb_next(lastp))) {
554 region = rb_entry(p, struct vm_region, vm_rb);
555 last = rb_entry(lastp, struct vm_region, vm_rb);
556
557 BUG_ON(region->vm_end <= region->vm_start);
558 BUG_ON(region->vm_top < region->vm_end);
559 BUG_ON(region->vm_start < last->vm_top);
560
561 lastp = p;
562 }
563}
564#else
565static void validate_nommu_regions(void)
566{
567}
568#endif
569
570
571
572
573static void add_nommu_region(struct vm_region *region)
574{
575 struct vm_region *pregion;
576 struct rb_node **p, *parent;
577
578 validate_nommu_regions();
579
580 parent = NULL;
581 p = &nommu_region_tree.rb_node;
582 while (*p) {
583 parent = *p;
584 pregion = rb_entry(parent, struct vm_region, vm_rb);
585 if (region->vm_start < pregion->vm_start)
586 p = &(*p)->rb_left;
587 else if (region->vm_start > pregion->vm_start)
588 p = &(*p)->rb_right;
589 else if (pregion == region)
590 return;
591 else
592 BUG();
593 }
594
595 rb_link_node(®ion->vm_rb, parent, p);
596 rb_insert_color(®ion->vm_rb, &nommu_region_tree);
597
598 validate_nommu_regions();
599}
600
601
602
603
604static void delete_nommu_region(struct vm_region *region)
605{
606 BUG_ON(!nommu_region_tree.rb_node);
607
608 validate_nommu_regions();
609 rb_erase(®ion->vm_rb, &nommu_region_tree);
610 validate_nommu_regions();
611}
612
613
614
615
616static void free_page_series(unsigned long from, unsigned long to)
617{
618 for (; from < to; from += PAGE_SIZE) {
619 struct page *page = virt_to_page(from);
620
621 atomic_long_dec(&mmap_pages_allocated);
622 put_page(page);
623 }
624}
625
626
627
628
629
630
631
632static void __put_nommu_region(struct vm_region *region)
633 __releases(nommu_region_sem)
634{
635 BUG_ON(!nommu_region_tree.rb_node);
636
637 if (--region->vm_usage == 0) {
638 if (region->vm_top > region->vm_start)
639 delete_nommu_region(region);
640 up_write(&nommu_region_sem);
641
642 if (region->vm_file)
643 fput(region->vm_file);
644
645
646
647 if (region->vm_flags & VM_MAPPED_COPY)
648 free_page_series(region->vm_start, region->vm_top);
649 kmem_cache_free(vm_region_jar, region);
650 } else {
651 up_write(&nommu_region_sem);
652 }
653}
654
655
656
657
658static void put_nommu_region(struct vm_region *region)
659{
660 down_write(&nommu_region_sem);
661 __put_nommu_region(region);
662}
663
664
665
666
667
668
669
670static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma)
671{
672 struct vm_area_struct *pvma, *prev;
673 struct address_space *mapping;
674 struct rb_node **p, *parent, *rb_prev;
675
676 BUG_ON(!vma->vm_region);
677
678 mm->map_count++;
679 vma->vm_mm = mm;
680
681
682 if (vma->vm_file) {
683 mapping = vma->vm_file->f_mapping;
684
685 i_mmap_lock_write(mapping);
686 flush_dcache_mmap_lock(mapping);
687 vma_interval_tree_insert(vma, &mapping->i_mmap);
688 flush_dcache_mmap_unlock(mapping);
689 i_mmap_unlock_write(mapping);
690 }
691
692
693 parent = rb_prev = NULL;
694 p = &mm->mm_rb.rb_node;
695 while (*p) {
696 parent = *p;
697 pvma = rb_entry(parent, struct vm_area_struct, vm_rb);
698
699
700
701 if (vma->vm_start < pvma->vm_start)
702 p = &(*p)->rb_left;
703 else if (vma->vm_start > pvma->vm_start) {
704 rb_prev = parent;
705 p = &(*p)->rb_right;
706 } else if (vma->vm_end < pvma->vm_end)
707 p = &(*p)->rb_left;
708 else if (vma->vm_end > pvma->vm_end) {
709 rb_prev = parent;
710 p = &(*p)->rb_right;
711 } else if (vma < pvma)
712 p = &(*p)->rb_left;
713 else if (vma > pvma) {
714 rb_prev = parent;
715 p = &(*p)->rb_right;
716 } else
717 BUG();
718 }
719
720 rb_link_node(&vma->vm_rb, parent, p);
721 rb_insert_color(&vma->vm_rb, &mm->mm_rb);
722
723
724 prev = NULL;
725 if (rb_prev)
726 prev = rb_entry(rb_prev, struct vm_area_struct, vm_rb);
727
728 __vma_link_list(mm, vma, prev, parent);
729}
730
731
732
733
734static void delete_vma_from_mm(struct vm_area_struct *vma)
735{
736 int i;
737 struct address_space *mapping;
738 struct mm_struct *mm = vma->vm_mm;
739 struct task_struct *curr = current;
740
741 mm->map_count--;
742 for (i = 0; i < VMACACHE_SIZE; i++) {
743
744 if (curr->vmacache.vmas[i] == vma) {
745 vmacache_invalidate(mm);
746 break;
747 }
748 }
749
750
751 if (vma->vm_file) {
752 mapping = vma->vm_file->f_mapping;
753
754 i_mmap_lock_write(mapping);
755 flush_dcache_mmap_lock(mapping);
756 vma_interval_tree_remove(vma, &mapping->i_mmap);
757 flush_dcache_mmap_unlock(mapping);
758 i_mmap_unlock_write(mapping);
759 }
760
761
762 rb_erase(&vma->vm_rb, &mm->mm_rb);
763
764 if (vma->vm_prev)
765 vma->vm_prev->vm_next = vma->vm_next;
766 else
767 mm->mmap = vma->vm_next;
768
769 if (vma->vm_next)
770 vma->vm_next->vm_prev = vma->vm_prev;
771}
772
773
774
775
776static void delete_vma(struct mm_struct *mm, struct vm_area_struct *vma)
777{
778 if (vma->vm_ops && vma->vm_ops->close)
779 vma->vm_ops->close(vma);
780 if (vma->vm_file)
781 fput(vma->vm_file);
782 put_nommu_region(vma->vm_region);
783 vm_area_free(vma);
784}
785
786
787
788
789
790struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr)
791{
792 struct vm_area_struct *vma;
793
794
795 vma = vmacache_find(mm, addr);
796 if (likely(vma))
797 return vma;
798
799
800
801 for (vma = mm->mmap; vma; vma = vma->vm_next) {
802 if (vma->vm_start > addr)
803 return NULL;
804 if (vma->vm_end > addr) {
805 vmacache_update(addr, vma);
806 return vma;
807 }
808 }
809
810 return NULL;
811}
812EXPORT_SYMBOL(find_vma);
813
814
815
816
817
818struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr)
819{
820 return find_vma(mm, addr);
821}
822
823
824
825
826
827int expand_stack(struct vm_area_struct *vma, unsigned long address)
828{
829 return -ENOMEM;
830}
831
832
833
834
835
836static struct vm_area_struct *find_vma_exact(struct mm_struct *mm,
837 unsigned long addr,
838 unsigned long len)
839{
840 struct vm_area_struct *vma;
841 unsigned long end = addr + len;
842
843
844 vma = vmacache_find_exact(mm, addr, end);
845 if (vma)
846 return vma;
847
848
849
850 for (vma = mm->mmap; vma; vma = vma->vm_next) {
851 if (vma->vm_start < addr)
852 continue;
853 if (vma->vm_start > addr)
854 return NULL;
855 if (vma->vm_end == end) {
856 vmacache_update(addr, vma);
857 return vma;
858 }
859 }
860
861 return NULL;
862}
863
864
865
866
867
868static int validate_mmap_request(struct file *file,
869 unsigned long addr,
870 unsigned long len,
871 unsigned long prot,
872 unsigned long flags,
873 unsigned long pgoff,
874 unsigned long *_capabilities)
875{
876 unsigned long capabilities, rlen;
877 int ret;
878
879
880 if (flags & MAP_FIXED)
881 return -EINVAL;
882
883 if ((flags & MAP_TYPE) != MAP_PRIVATE &&
884 (flags & MAP_TYPE) != MAP_SHARED)
885 return -EINVAL;
886
887 if (!len)
888 return -EINVAL;
889
890
891 rlen = PAGE_ALIGN(len);
892 if (!rlen || rlen > TASK_SIZE)
893 return -ENOMEM;
894
895
896 if ((pgoff + (rlen >> PAGE_SHIFT)) < pgoff)
897 return -EOVERFLOW;
898
899 if (file) {
900
901 if (!file->f_op->mmap)
902 return -ENODEV;
903
904
905
906
907
908 if (file->f_op->mmap_capabilities) {
909 capabilities = file->f_op->mmap_capabilities(file);
910 } else {
911
912
913 switch (file_inode(file)->i_mode & S_IFMT) {
914 case S_IFREG:
915 case S_IFBLK:
916 capabilities = NOMMU_MAP_COPY;
917 break;
918
919 case S_IFCHR:
920 capabilities =
921 NOMMU_MAP_DIRECT |
922 NOMMU_MAP_READ |
923 NOMMU_MAP_WRITE;
924 break;
925
926 default:
927 return -EINVAL;
928 }
929 }
930
931
932
933 if (!file->f_op->get_unmapped_area)
934 capabilities &= ~NOMMU_MAP_DIRECT;
935 if (!(file->f_mode & FMODE_CAN_READ))
936 capabilities &= ~NOMMU_MAP_COPY;
937
938
939 if (!(file->f_mode & FMODE_READ))
940 return -EACCES;
941
942 if (flags & MAP_SHARED) {
943
944 if ((prot & PROT_WRITE) &&
945 !(file->f_mode & FMODE_WRITE))
946 return -EACCES;
947
948 if (IS_APPEND(file_inode(file)) &&
949 (file->f_mode & FMODE_WRITE))
950 return -EACCES;
951
952 if (locks_verify_locked(file))
953 return -EAGAIN;
954
955 if (!(capabilities & NOMMU_MAP_DIRECT))
956 return -ENODEV;
957
958
959 capabilities &= ~NOMMU_MAP_COPY;
960 } else {
961
962
963 if (!(capabilities & NOMMU_MAP_COPY))
964 return -ENODEV;
965
966
967
968 if (prot & PROT_WRITE)
969 capabilities &= ~NOMMU_MAP_DIRECT;
970 }
971
972 if (capabilities & NOMMU_MAP_DIRECT) {
973 if (((prot & PROT_READ) && !(capabilities & NOMMU_MAP_READ)) ||
974 ((prot & PROT_WRITE) && !(capabilities & NOMMU_MAP_WRITE)) ||
975 ((prot & PROT_EXEC) && !(capabilities & NOMMU_MAP_EXEC))
976 ) {
977 capabilities &= ~NOMMU_MAP_DIRECT;
978 if (flags & MAP_SHARED) {
979 pr_warn("MAP_SHARED not completely supported on !MMU\n");
980 return -EINVAL;
981 }
982 }
983 }
984
985
986
987 if (path_noexec(&file->f_path)) {
988 if (prot & PROT_EXEC)
989 return -EPERM;
990 } else if ((prot & PROT_READ) && !(prot & PROT_EXEC)) {
991
992 if (current->personality & READ_IMPLIES_EXEC) {
993 if (capabilities & NOMMU_MAP_EXEC)
994 prot |= PROT_EXEC;
995 }
996 } else if ((prot & PROT_READ) &&
997 (prot & PROT_EXEC) &&
998 !(capabilities & NOMMU_MAP_EXEC)
999 ) {
1000
1001 capabilities &= ~NOMMU_MAP_DIRECT;
1002 }
1003 } else {
1004
1005
1006
1007 capabilities = NOMMU_MAP_COPY;
1008
1009
1010 if ((prot & PROT_READ) &&
1011 (current->personality & READ_IMPLIES_EXEC))
1012 prot |= PROT_EXEC;
1013 }
1014
1015
1016 ret = security_mmap_addr(addr);
1017 if (ret < 0)
1018 return ret;
1019
1020
1021 *_capabilities = capabilities;
1022 return 0;
1023}
1024
1025
1026
1027
1028
1029static unsigned long determine_vm_flags(struct file *file,
1030 unsigned long prot,
1031 unsigned long flags,
1032 unsigned long capabilities)
1033{
1034 unsigned long vm_flags;
1035
1036 vm_flags = calc_vm_prot_bits(prot, 0) | calc_vm_flag_bits(flags);
1037
1038
1039 if (!(capabilities & NOMMU_MAP_DIRECT)) {
1040
1041 vm_flags |= VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;
1042 if (file && !(prot & PROT_WRITE))
1043 vm_flags |= VM_MAYSHARE;
1044 } else {
1045
1046
1047
1048 vm_flags |= VM_MAYSHARE | (capabilities & NOMMU_VMFLAGS);
1049 if (flags & MAP_SHARED)
1050 vm_flags |= VM_SHARED;
1051 }
1052
1053
1054
1055
1056
1057 if ((flags & MAP_PRIVATE) && current->ptrace)
1058 vm_flags &= ~VM_MAYSHARE;
1059
1060 return vm_flags;
1061}
1062
1063
1064
1065
1066
1067static int do_mmap_shared_file(struct vm_area_struct *vma)
1068{
1069 int ret;
1070
1071 ret = call_mmap(vma->vm_file, vma);
1072 if (ret == 0) {
1073 vma->vm_region->vm_top = vma->vm_region->vm_end;
1074 return 0;
1075 }
1076 if (ret != -ENOSYS)
1077 return ret;
1078
1079
1080
1081
1082 return -ENODEV;
1083}
1084
1085
1086
1087
1088static int do_mmap_private(struct vm_area_struct *vma,
1089 struct vm_region *region,
1090 unsigned long len,
1091 unsigned long capabilities)
1092{
1093 unsigned long total, point;
1094 void *base;
1095 int ret, order;
1096
1097
1098
1099
1100
1101 if (capabilities & NOMMU_MAP_DIRECT) {
1102 ret = call_mmap(vma->vm_file, vma);
1103 if (ret == 0) {
1104
1105 BUG_ON(!(vma->vm_flags & VM_MAYSHARE));
1106 vma->vm_region->vm_top = vma->vm_region->vm_end;
1107 return 0;
1108 }
1109 if (ret != -ENOSYS)
1110 return ret;
1111
1112
1113
1114
1115 }
1116
1117
1118
1119
1120
1121
1122 order = get_order(len);
1123 total = 1 << order;
1124 point = len >> PAGE_SHIFT;
1125
1126
1127 if (sysctl_nr_trim_pages && total - point >= sysctl_nr_trim_pages)
1128 total = point;
1129
1130 base = alloc_pages_exact(total << PAGE_SHIFT, GFP_KERNEL);
1131 if (!base)
1132 goto enomem;
1133
1134 atomic_long_add(total, &mmap_pages_allocated);
1135
1136 region->vm_flags = vma->vm_flags |= VM_MAPPED_COPY;
1137 region->vm_start = (unsigned long) base;
1138 region->vm_end = region->vm_start + len;
1139 region->vm_top = region->vm_start + (total << PAGE_SHIFT);
1140
1141 vma->vm_start = region->vm_start;
1142 vma->vm_end = region->vm_start + len;
1143
1144 if (vma->vm_file) {
1145
1146 loff_t fpos;
1147
1148 fpos = vma->vm_pgoff;
1149 fpos <<= PAGE_SHIFT;
1150
1151 ret = kernel_read(vma->vm_file, base, len, &fpos);
1152 if (ret < 0)
1153 goto error_free;
1154
1155
1156 if (ret < len)
1157 memset(base + ret, 0, len - ret);
1158
1159 } else {
1160 vma_set_anonymous(vma);
1161 }
1162
1163 return 0;
1164
1165error_free:
1166 free_page_series(region->vm_start, region->vm_top);
1167 region->vm_start = vma->vm_start = 0;
1168 region->vm_end = vma->vm_end = 0;
1169 region->vm_top = 0;
1170 return ret;
1171
1172enomem:
1173 pr_err("Allocation of length %lu from process %d (%s) failed\n",
1174 len, current->pid, current->comm);
1175 show_free_areas(0, NULL);
1176 return -ENOMEM;
1177}
1178
1179
1180
1181
1182unsigned long do_mmap(struct file *file,
1183 unsigned long addr,
1184 unsigned long len,
1185 unsigned long prot,
1186 unsigned long flags,
1187 vm_flags_t vm_flags,
1188 unsigned long pgoff,
1189 unsigned long *populate,
1190 struct list_head *uf)
1191{
1192 struct vm_area_struct *vma;
1193 struct vm_region *region;
1194 struct rb_node *rb;
1195 unsigned long capabilities, result;
1196 int ret;
1197
1198 *populate = 0;
1199
1200
1201
1202 ret = validate_mmap_request(file, addr, len, prot, flags, pgoff,
1203 &capabilities);
1204 if (ret < 0)
1205 return ret;
1206
1207
1208 addr = 0;
1209 len = PAGE_ALIGN(len);
1210
1211
1212
1213 vm_flags |= determine_vm_flags(file, prot, flags, capabilities);
1214
1215
1216 region = kmem_cache_zalloc(vm_region_jar, GFP_KERNEL);
1217 if (!region)
1218 goto error_getting_region;
1219
1220 vma = vm_area_alloc(current->mm);
1221 if (!vma)
1222 goto error_getting_vma;
1223
1224 region->vm_usage = 1;
1225 region->vm_flags = vm_flags;
1226 region->vm_pgoff = pgoff;
1227
1228 vma->vm_flags = vm_flags;
1229 vma->vm_pgoff = pgoff;
1230
1231 if (file) {
1232 region->vm_file = get_file(file);
1233 vma->vm_file = get_file(file);
1234 }
1235
1236 down_write(&nommu_region_sem);
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246 if (vm_flags & VM_MAYSHARE) {
1247 struct vm_region *pregion;
1248 unsigned long pglen, rpglen, pgend, rpgend, start;
1249
1250 pglen = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
1251 pgend = pgoff + pglen;
1252
1253 for (rb = rb_first(&nommu_region_tree); rb; rb = rb_next(rb)) {
1254 pregion = rb_entry(rb, struct vm_region, vm_rb);
1255
1256 if (!(pregion->vm_flags & VM_MAYSHARE))
1257 continue;
1258
1259
1260 if (file_inode(pregion->vm_file) !=
1261 file_inode(file))
1262 continue;
1263
1264 if (pregion->vm_pgoff >= pgend)
1265 continue;
1266
1267 rpglen = pregion->vm_end - pregion->vm_start;
1268 rpglen = (rpglen + PAGE_SIZE - 1) >> PAGE_SHIFT;
1269 rpgend = pregion->vm_pgoff + rpglen;
1270 if (pgoff >= rpgend)
1271 continue;
1272
1273
1274
1275 if ((pregion->vm_pgoff != pgoff || rpglen != pglen) &&
1276 !(pgoff >= pregion->vm_pgoff && pgend <= rpgend)) {
1277
1278 if (!(capabilities & NOMMU_MAP_DIRECT))
1279 goto sharing_violation;
1280 continue;
1281 }
1282
1283
1284 pregion->vm_usage++;
1285 vma->vm_region = pregion;
1286 start = pregion->vm_start;
1287 start += (pgoff - pregion->vm_pgoff) << PAGE_SHIFT;
1288 vma->vm_start = start;
1289 vma->vm_end = start + len;
1290
1291 if (pregion->vm_flags & VM_MAPPED_COPY)
1292 vma->vm_flags |= VM_MAPPED_COPY;
1293 else {
1294 ret = do_mmap_shared_file(vma);
1295 if (ret < 0) {
1296 vma->vm_region = NULL;
1297 vma->vm_start = 0;
1298 vma->vm_end = 0;
1299 pregion->vm_usage--;
1300 pregion = NULL;
1301 goto error_just_free;
1302 }
1303 }
1304 fput(region->vm_file);
1305 kmem_cache_free(vm_region_jar, region);
1306 region = pregion;
1307 result = start;
1308 goto share;
1309 }
1310
1311
1312
1313
1314
1315 if (capabilities & NOMMU_MAP_DIRECT) {
1316 addr = file->f_op->get_unmapped_area(file, addr, len,
1317 pgoff, flags);
1318 if (IS_ERR_VALUE(addr)) {
1319 ret = addr;
1320 if (ret != -ENOSYS)
1321 goto error_just_free;
1322
1323
1324
1325
1326 ret = -ENODEV;
1327 if (!(capabilities & NOMMU_MAP_COPY))
1328 goto error_just_free;
1329
1330 capabilities &= ~NOMMU_MAP_DIRECT;
1331 } else {
1332 vma->vm_start = region->vm_start = addr;
1333 vma->vm_end = region->vm_end = addr + len;
1334 }
1335 }
1336 }
1337
1338 vma->vm_region = region;
1339
1340
1341
1342
1343 if (file && vma->vm_flags & VM_SHARED)
1344 ret = do_mmap_shared_file(vma);
1345 else
1346 ret = do_mmap_private(vma, region, len, capabilities);
1347 if (ret < 0)
1348 goto error_just_free;
1349 add_nommu_region(region);
1350
1351
1352 if (!vma->vm_file && !(flags & MAP_UNINITIALIZED))
1353 memset((void *)region->vm_start, 0,
1354 region->vm_end - region->vm_start);
1355
1356
1357 result = vma->vm_start;
1358
1359 current->mm->total_vm += len >> PAGE_SHIFT;
1360
1361share:
1362 add_vma_to_mm(current->mm, vma);
1363
1364
1365
1366 if (vma->vm_flags & VM_EXEC && !region->vm_icache_flushed) {
1367 flush_icache_range(region->vm_start, region->vm_end);
1368 region->vm_icache_flushed = true;
1369 }
1370
1371 up_write(&nommu_region_sem);
1372
1373 return result;
1374
1375error_just_free:
1376 up_write(&nommu_region_sem);
1377error:
1378 if (region->vm_file)
1379 fput(region->vm_file);
1380 kmem_cache_free(vm_region_jar, region);
1381 if (vma->vm_file)
1382 fput(vma->vm_file);
1383 vm_area_free(vma);
1384 return ret;
1385
1386sharing_violation:
1387 up_write(&nommu_region_sem);
1388 pr_warn("Attempt to share mismatched mappings\n");
1389 ret = -EINVAL;
1390 goto error;
1391
1392error_getting_vma:
1393 kmem_cache_free(vm_region_jar, region);
1394 pr_warn("Allocation of vma for %lu byte allocation from process %d failed\n",
1395 len, current->pid);
1396 show_free_areas(0, NULL);
1397 return -ENOMEM;
1398
1399error_getting_region:
1400 pr_warn("Allocation of vm region for %lu byte allocation from process %d failed\n",
1401 len, current->pid);
1402 show_free_areas(0, NULL);
1403 return -ENOMEM;
1404}
1405
1406unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len,
1407 unsigned long prot, unsigned long flags,
1408 unsigned long fd, unsigned long pgoff)
1409{
1410 struct file *file = NULL;
1411 unsigned long retval = -EBADF;
1412
1413 audit_mmap_fd(fd, flags);
1414 if (!(flags & MAP_ANONYMOUS)) {
1415 file = fget(fd);
1416 if (!file)
1417 goto out;
1418 }
1419
1420 flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
1421
1422 retval = vm_mmap_pgoff(file, addr, len, prot, flags, pgoff);
1423
1424 if (file)
1425 fput(file);
1426out:
1427 return retval;
1428}
1429
1430SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len,
1431 unsigned long, prot, unsigned long, flags,
1432 unsigned long, fd, unsigned long, pgoff)
1433{
1434 return ksys_mmap_pgoff(addr, len, prot, flags, fd, pgoff);
1435}
1436
1437#ifdef __ARCH_WANT_SYS_OLD_MMAP
1438struct mmap_arg_struct {
1439 unsigned long addr;
1440 unsigned long len;
1441 unsigned long prot;
1442 unsigned long flags;
1443 unsigned long fd;
1444 unsigned long offset;
1445};
1446
1447SYSCALL_DEFINE1(old_mmap, struct mmap_arg_struct __user *, arg)
1448{
1449 struct mmap_arg_struct a;
1450
1451 if (copy_from_user(&a, arg, sizeof(a)))
1452 return -EFAULT;
1453 if (offset_in_page(a.offset))
1454 return -EINVAL;
1455
1456 return ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd,
1457 a.offset >> PAGE_SHIFT);
1458}
1459#endif
1460
1461
1462
1463
1464
1465int split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
1466 unsigned long addr, int new_below)
1467{
1468 struct vm_area_struct *new;
1469 struct vm_region *region;
1470 unsigned long npages;
1471
1472
1473
1474 if (vma->vm_file)
1475 return -ENOMEM;
1476
1477 if (mm->map_count >= sysctl_max_map_count)
1478 return -ENOMEM;
1479
1480 region = kmem_cache_alloc(vm_region_jar, GFP_KERNEL);
1481 if (!region)
1482 return -ENOMEM;
1483
1484 new = vm_area_dup(vma);
1485 if (!new) {
1486 kmem_cache_free(vm_region_jar, region);
1487 return -ENOMEM;
1488 }
1489
1490
1491 *region = *vma->vm_region;
1492 new->vm_region = region;
1493
1494 npages = (addr - vma->vm_start) >> PAGE_SHIFT;
1495
1496 if (new_below) {
1497 region->vm_top = region->vm_end = new->vm_end = addr;
1498 } else {
1499 region->vm_start = new->vm_start = addr;
1500 region->vm_pgoff = new->vm_pgoff += npages;
1501 }
1502
1503 if (new->vm_ops && new->vm_ops->open)
1504 new->vm_ops->open(new);
1505
1506 delete_vma_from_mm(vma);
1507 down_write(&nommu_region_sem);
1508 delete_nommu_region(vma->vm_region);
1509 if (new_below) {
1510 vma->vm_region->vm_start = vma->vm_start = addr;
1511 vma->vm_region->vm_pgoff = vma->vm_pgoff += npages;
1512 } else {
1513 vma->vm_region->vm_end = vma->vm_end = addr;
1514 vma->vm_region->vm_top = addr;
1515 }
1516 add_nommu_region(vma->vm_region);
1517 add_nommu_region(new->vm_region);
1518 up_write(&nommu_region_sem);
1519 add_vma_to_mm(mm, vma);
1520 add_vma_to_mm(mm, new);
1521 return 0;
1522}
1523
1524
1525
1526
1527
1528static int shrink_vma(struct mm_struct *mm,
1529 struct vm_area_struct *vma,
1530 unsigned long from, unsigned long to)
1531{
1532 struct vm_region *region;
1533
1534
1535
1536 delete_vma_from_mm(vma);
1537 if (from > vma->vm_start)
1538 vma->vm_end = from;
1539 else
1540 vma->vm_start = to;
1541 add_vma_to_mm(mm, vma);
1542
1543
1544 region = vma->vm_region;
1545 BUG_ON(region->vm_usage != 1);
1546
1547 down_write(&nommu_region_sem);
1548 delete_nommu_region(region);
1549 if (from > region->vm_start) {
1550 to = region->vm_top;
1551 region->vm_top = region->vm_end = from;
1552 } else {
1553 region->vm_start = to;
1554 }
1555 add_nommu_region(region);
1556 up_write(&nommu_region_sem);
1557
1558 free_page_series(from, to);
1559 return 0;
1560}
1561
1562
1563
1564
1565
1566
1567int do_munmap(struct mm_struct *mm, unsigned long start, size_t len, struct list_head *uf)
1568{
1569 struct vm_area_struct *vma;
1570 unsigned long end;
1571 int ret;
1572
1573 len = PAGE_ALIGN(len);
1574 if (len == 0)
1575 return -EINVAL;
1576
1577 end = start + len;
1578
1579
1580 vma = find_vma(mm, start);
1581 if (!vma) {
1582 static int limit;
1583 if (limit < 5) {
1584 pr_warn("munmap of memory not mmapped by process %d (%s): 0x%lx-0x%lx\n",
1585 current->pid, current->comm,
1586 start, start + len - 1);
1587 limit++;
1588 }
1589 return -EINVAL;
1590 }
1591
1592
1593 if (vma->vm_file) {
1594 do {
1595 if (start > vma->vm_start)
1596 return -EINVAL;
1597 if (end == vma->vm_end)
1598 goto erase_whole_vma;
1599 vma = vma->vm_next;
1600 } while (vma);
1601 return -EINVAL;
1602 } else {
1603
1604 if (start == vma->vm_start && end == vma->vm_end)
1605 goto erase_whole_vma;
1606 if (start < vma->vm_start || end > vma->vm_end)
1607 return -EINVAL;
1608 if (offset_in_page(start))
1609 return -EINVAL;
1610 if (end != vma->vm_end && offset_in_page(end))
1611 return -EINVAL;
1612 if (start != vma->vm_start && end != vma->vm_end) {
1613 ret = split_vma(mm, vma, start, 1);
1614 if (ret < 0)
1615 return ret;
1616 }
1617 return shrink_vma(mm, vma, start, end);
1618 }
1619
1620erase_whole_vma:
1621 delete_vma_from_mm(vma);
1622 delete_vma(mm, vma);
1623 return 0;
1624}
1625EXPORT_SYMBOL(do_munmap);
1626
1627int vm_munmap(unsigned long addr, size_t len)
1628{
1629 struct mm_struct *mm = current->mm;
1630 int ret;
1631
1632 down_write(&mm->mmap_sem);
1633 ret = do_munmap(mm, addr, len, NULL);
1634 up_write(&mm->mmap_sem);
1635 return ret;
1636}
1637EXPORT_SYMBOL(vm_munmap);
1638
1639SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len)
1640{
1641 return vm_munmap(addr, len);
1642}
1643
1644
1645
1646
1647void exit_mmap(struct mm_struct *mm)
1648{
1649 struct vm_area_struct *vma;
1650
1651 if (!mm)
1652 return;
1653
1654 mm->total_vm = 0;
1655
1656 while ((vma = mm->mmap)) {
1657 mm->mmap = vma->vm_next;
1658 delete_vma_from_mm(vma);
1659 delete_vma(mm, vma);
1660 cond_resched();
1661 }
1662}
1663
1664int vm_brk(unsigned long addr, unsigned long len)
1665{
1666 return -ENOMEM;
1667}
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679static unsigned long do_mremap(unsigned long addr,
1680 unsigned long old_len, unsigned long new_len,
1681 unsigned long flags, unsigned long new_addr)
1682{
1683 struct vm_area_struct *vma;
1684
1685
1686 old_len = PAGE_ALIGN(old_len);
1687 new_len = PAGE_ALIGN(new_len);
1688 if (old_len == 0 || new_len == 0)
1689 return (unsigned long) -EINVAL;
1690
1691 if (offset_in_page(addr))
1692 return -EINVAL;
1693
1694 if (flags & MREMAP_FIXED && new_addr != addr)
1695 return (unsigned long) -EINVAL;
1696
1697 vma = find_vma_exact(current->mm, addr, old_len);
1698 if (!vma)
1699 return (unsigned long) -EINVAL;
1700
1701 if (vma->vm_end != vma->vm_start + old_len)
1702 return (unsigned long) -EFAULT;
1703
1704 if (vma->vm_flags & VM_MAYSHARE)
1705 return (unsigned long) -EPERM;
1706
1707 if (new_len > vma->vm_region->vm_end - vma->vm_region->vm_start)
1708 return (unsigned long) -ENOMEM;
1709
1710
1711 vma->vm_end = vma->vm_start + new_len;
1712 return vma->vm_start;
1713}
1714
1715SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
1716 unsigned long, new_len, unsigned long, flags,
1717 unsigned long, new_addr)
1718{
1719 unsigned long ret;
1720
1721 down_write(¤t->mm->mmap_sem);
1722 ret = do_mremap(addr, old_len, new_len, flags, new_addr);
1723 up_write(¤t->mm->mmap_sem);
1724 return ret;
1725}
1726
1727struct page *follow_page(struct vm_area_struct *vma, unsigned long address,
1728 unsigned int foll_flags)
1729{
1730 return NULL;
1731}
1732
1733int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr,
1734 unsigned long pfn, unsigned long size, pgprot_t prot)
1735{
1736 if (addr != (pfn << PAGE_SHIFT))
1737 return -EINVAL;
1738
1739 vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
1740 return 0;
1741}
1742EXPORT_SYMBOL(remap_pfn_range);
1743
1744int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len)
1745{
1746 unsigned long pfn = start >> PAGE_SHIFT;
1747 unsigned long vm_len = vma->vm_end - vma->vm_start;
1748
1749 pfn += vma->vm_pgoff;
1750 return io_remap_pfn_range(vma, vma->vm_start, pfn, vm_len, vma->vm_page_prot);
1751}
1752EXPORT_SYMBOL(vm_iomap_memory);
1753
1754int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
1755 unsigned long pgoff)
1756{
1757 unsigned int size = vma->vm_end - vma->vm_start;
1758
1759 if (!(vma->vm_flags & VM_USERMAP))
1760 return -EINVAL;
1761
1762 vma->vm_start = (unsigned long)(addr + (pgoff << PAGE_SHIFT));
1763 vma->vm_end = vma->vm_start + size;
1764
1765 return 0;
1766}
1767EXPORT_SYMBOL(remap_vmalloc_range);
1768
1769unsigned long arch_get_unmapped_area(struct file *file, unsigned long addr,
1770 unsigned long len, unsigned long pgoff, unsigned long flags)
1771{
1772 return -ENOMEM;
1773}
1774
1775vm_fault_t filemap_fault(struct vm_fault *vmf)
1776{
1777 BUG();
1778 return 0;
1779}
1780EXPORT_SYMBOL(filemap_fault);
1781
1782void filemap_map_pages(struct vm_fault *vmf,
1783 pgoff_t start_pgoff, pgoff_t end_pgoff)
1784{
1785 BUG();
1786}
1787EXPORT_SYMBOL(filemap_map_pages);
1788
1789int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm,
1790 unsigned long addr, void *buf, int len, unsigned int gup_flags)
1791{
1792 struct vm_area_struct *vma;
1793 int write = gup_flags & FOLL_WRITE;
1794
1795 down_read(&mm->mmap_sem);
1796
1797
1798 vma = find_vma(mm, addr);
1799 if (vma) {
1800
1801 if (addr + len >= vma->vm_end)
1802 len = vma->vm_end - addr;
1803
1804
1805 if (write && vma->vm_flags & VM_MAYWRITE)
1806 copy_to_user_page(vma, NULL, addr,
1807 (void *) addr, buf, len);
1808 else if (!write && vma->vm_flags & VM_MAYREAD)
1809 copy_from_user_page(vma, NULL, addr,
1810 buf, (void *) addr, len);
1811 else
1812 len = 0;
1813 } else {
1814 len = 0;
1815 }
1816
1817 up_read(&mm->mmap_sem);
1818
1819 return len;
1820}
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832int access_remote_vm(struct mm_struct *mm, unsigned long addr,
1833 void *buf, int len, unsigned int gup_flags)
1834{
1835 return __access_remote_vm(NULL, mm, addr, buf, len, gup_flags);
1836}
1837
1838
1839
1840
1841
1842int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len,
1843 unsigned int gup_flags)
1844{
1845 struct mm_struct *mm;
1846
1847 if (addr + len < addr)
1848 return 0;
1849
1850 mm = get_task_mm(tsk);
1851 if (!mm)
1852 return 0;
1853
1854 len = __access_remote_vm(tsk, mm, addr, buf, len, gup_flags);
1855
1856 mmput(mm);
1857 return len;
1858}
1859EXPORT_SYMBOL_GPL(access_process_vm);
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872int nommu_shrink_inode_mappings(struct inode *inode, size_t size,
1873 size_t newsize)
1874{
1875 struct vm_area_struct *vma;
1876 struct vm_region *region;
1877 pgoff_t low, high;
1878 size_t r_size, r_top;
1879
1880 low = newsize >> PAGE_SHIFT;
1881 high = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
1882
1883 down_write(&nommu_region_sem);
1884 i_mmap_lock_read(inode->i_mapping);
1885
1886
1887 vma_interval_tree_foreach(vma, &inode->i_mapping->i_mmap, low, high) {
1888
1889
1890 if (vma->vm_flags & VM_SHARED) {
1891 i_mmap_unlock_read(inode->i_mapping);
1892 up_write(&nommu_region_sem);
1893 return -ETXTBSY;
1894 }
1895 }
1896
1897
1898
1899
1900
1901
1902
1903 vma_interval_tree_foreach(vma, &inode->i_mapping->i_mmap, 0, ULONG_MAX) {
1904 if (!(vma->vm_flags & VM_SHARED))
1905 continue;
1906
1907 region = vma->vm_region;
1908 r_size = region->vm_top - region->vm_start;
1909 r_top = (region->vm_pgoff << PAGE_SHIFT) + r_size;
1910
1911 if (r_top > newsize) {
1912 region->vm_top -= r_top - newsize;
1913 if (region->vm_end > region->vm_top)
1914 region->vm_end = region->vm_top;
1915 }
1916 }
1917
1918 i_mmap_unlock_read(inode->i_mapping);
1919 up_write(&nommu_region_sem);
1920 return 0;
1921}
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933static int __meminit init_user_reserve(void)
1934{
1935 unsigned long free_kbytes;
1936
1937 free_kbytes = global_zone_page_state(NR_FREE_PAGES) << (PAGE_SHIFT - 10);
1938
1939 sysctl_user_reserve_kbytes = min(free_kbytes / 32, 1UL << 17);
1940 return 0;
1941}
1942subsys_initcall(init_user_reserve);
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954static int __meminit init_admin_reserve(void)
1955{
1956 unsigned long free_kbytes;
1957
1958 free_kbytes = global_zone_page_state(NR_FREE_PAGES) << (PAGE_SHIFT - 10);
1959
1960 sysctl_admin_reserve_kbytes = min(free_kbytes / 32, 1UL << 13);
1961 return 0;
1962}
1963subsys_initcall(init_admin_reserve);
1964