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