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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * linux/arch/arm/mm/mmap.c | |
4 | */ | |
1da177e4 LT |
5 | #include <linux/fs.h> |
6 | #include <linux/mm.h> | |
7 | #include <linux/mman.h> | |
8 | #include <linux/shm.h> | |
3f07c014 | 9 | #include <linux/sched/signal.h> |
01042607 | 10 | #include <linux/sched/mm.h> |
09d9bae0 | 11 | #include <linux/io.h> |
df5419a9 | 12 | #include <linux/personality.h> |
cc92c28b | 13 | #include <linux/random.h> |
41dfaa93 | 14 | #include <asm/cachetype.h> |
1da177e4 LT |
15 | |
16 | #define COLOUR_ALIGN(addr,pgoff) \ | |
17 | ((((addr)+SHMLBA-1)&~(SHMLBA-1)) + \ | |
18 | (((pgoff)<<PAGE_SHIFT) & (SHMLBA-1))) | |
19 | ||
20 | /* | |
21 | * We need to ensure that shared mappings are correctly aligned to | |
22 | * avoid aliasing issues with VIPT caches. We need to ensure that | |
23 | * a specific page of an object is always mapped at a multiple of | |
24 | * SHMLBA bytes. | |
25 | * | |
26 | * We unconditionally provide this function for all cases, however | |
27 | * in the VIVT case, we optimise out the alignment rules. | |
28 | */ | |
29 | unsigned long | |
30 | arch_get_unmapped_area(struct file *filp, unsigned long addr, | |
31 | unsigned long len, unsigned long pgoff, unsigned long flags) | |
32 | { | |
33 | struct mm_struct *mm = current->mm; | |
34 | struct vm_area_struct *vma; | |
41dfaa93 RH |
35 | int do_align = 0; |
36 | int aliasing = cache_is_vipt_aliasing(); | |
394ef640 | 37 | struct vm_unmapped_area_info info; |
1da177e4 LT |
38 | |
39 | /* | |
40 | * We only need to do colour alignment if either the I or D | |
41dfaa93 | 41 | * caches alias. |
1da177e4 | 42 | */ |
41dfaa93 RH |
43 | if (aliasing) |
44 | do_align = filp || (flags & MAP_SHARED); | |
1da177e4 LT |
45 | |
46 | /* | |
acec0ac0 | 47 | * We enforce the MAP_FIXED case. |
1da177e4 LT |
48 | */ |
49 | if (flags & MAP_FIXED) { | |
e77414e0 AV |
50 | if (aliasing && flags & MAP_SHARED && |
51 | (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)) | |
1da177e4 LT |
52 | return -EINVAL; |
53 | return addr; | |
54 | } | |
55 | ||
56 | if (len > TASK_SIZE) | |
57 | return -ENOMEM; | |
58 | ||
59 | if (addr) { | |
60 | if (do_align) | |
61 | addr = COLOUR_ALIGN(addr, pgoff); | |
62 | else | |
63 | addr = PAGE_ALIGN(addr); | |
64 | ||
65 | vma = find_vma(mm, addr); | |
66 | if (TASK_SIZE - len >= addr && | |
1be7107f | 67 | (!vma || addr + len <= vm_start_gap(vma))) |
1da177e4 LT |
68 | return addr; |
69 | } | |
1da177e4 | 70 | |
394ef640 ML |
71 | info.flags = 0; |
72 | info.length = len; | |
73 | info.low_limit = mm->mmap_base; | |
74 | info.high_limit = TASK_SIZE; | |
75 | info.align_mask = do_align ? (PAGE_MASK & (SHMLBA - 1)) : 0; | |
76 | info.align_offset = pgoff << PAGE_SHIFT; | |
77 | return vm_unmapped_area(&info); | |
1da177e4 LT |
78 | } |
79 | ||
7dbaa466 RH |
80 | unsigned long |
81 | arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, | |
82 | const unsigned long len, const unsigned long pgoff, | |
83 | const unsigned long flags) | |
84 | { | |
85 | struct vm_area_struct *vma; | |
86 | struct mm_struct *mm = current->mm; | |
87 | unsigned long addr = addr0; | |
88 | int do_align = 0; | |
89 | int aliasing = cache_is_vipt_aliasing(); | |
394ef640 | 90 | struct vm_unmapped_area_info info; |
7dbaa466 RH |
91 | |
92 | /* | |
93 | * We only need to do colour alignment if either the I or D | |
94 | * caches alias. | |
95 | */ | |
96 | if (aliasing) | |
97 | do_align = filp || (flags & MAP_SHARED); | |
98 | ||
99 | /* requested length too big for entire address space */ | |
100 | if (len > TASK_SIZE) | |
101 | return -ENOMEM; | |
102 | ||
103 | if (flags & MAP_FIXED) { | |
104 | if (aliasing && flags & MAP_SHARED && | |
105 | (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)) | |
106 | return -EINVAL; | |
107 | return addr; | |
108 | } | |
109 | ||
110 | /* requesting a specific address */ | |
111 | if (addr) { | |
112 | if (do_align) | |
113 | addr = COLOUR_ALIGN(addr, pgoff); | |
114 | else | |
115 | addr = PAGE_ALIGN(addr); | |
116 | vma = find_vma(mm, addr); | |
117 | if (TASK_SIZE - len >= addr && | |
1be7107f | 118 | (!vma || addr + len <= vm_start_gap(vma))) |
7dbaa466 RH |
119 | return addr; |
120 | } | |
121 | ||
394ef640 ML |
122 | info.flags = VM_UNMAPPED_AREA_TOPDOWN; |
123 | info.length = len; | |
d8aa712c | 124 | info.low_limit = FIRST_USER_ADDRESS; |
394ef640 ML |
125 | info.high_limit = mm->mmap_base; |
126 | info.align_mask = do_align ? (PAGE_MASK & (SHMLBA - 1)) : 0; | |
127 | info.align_offset = pgoff << PAGE_SHIFT; | |
128 | addr = vm_unmapped_area(&info); | |
7dbaa466 | 129 | |
7dbaa466 RH |
130 | /* |
131 | * A failed mmap() very likely causes application failure, | |
132 | * so fall back to the bottom-up function here. This scenario | |
133 | * can happen with large stack limits and large mmap() | |
134 | * allocations. | |
135 | */ | |
394ef640 ML |
136 | if (addr & ~PAGE_MASK) { |
137 | VM_BUG_ON(addr != -ENOMEM); | |
138 | info.flags = 0; | |
139 | info.low_limit = mm->mmap_base; | |
140 | info.high_limit = TASK_SIZE; | |
141 | addr = vm_unmapped_area(&info); | |
142 | } | |
7dbaa466 RH |
143 | |
144 | return addr; | |
145 | } | |
146 | ||
51635ad2 LB |
147 | /* |
148 | * You really shouldn't be using read() or write() on /dev/mem. This | |
149 | * might go away in the future. | |
150 | */ | |
7e6735c3 | 151 | int valid_phys_addr_range(phys_addr_t addr, size_t size) |
51635ad2 | 152 | { |
9ae3ae0b AR |
153 | if (addr < PHYS_OFFSET) |
154 | return 0; | |
6806bfe1 | 155 | if (addr + size > __pa(high_memory - 1) + 1) |
51635ad2 LB |
156 | return 0; |
157 | ||
158 | return 1; | |
159 | } | |
160 | ||
161 | /* | |
3159f372 | 162 | * Do not allow /dev/mem mappings beyond the supported physical range. |
51635ad2 LB |
163 | */ |
164 | int valid_mmap_phys_addr_range(unsigned long pfn, size_t size) | |
165 | { | |
3159f372 | 166 | return (pfn + (size >> PAGE_SHIFT)) <= (1 + (PHYS_MASK >> PAGE_SHIFT)); |
51635ad2 | 167 | } |