Commit | Line | Data |
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1da177e4 LT |
1 | #include <linux/errno.h> |
2 | #include <linux/sched.h> | |
3 | #include <linux/syscalls.h> | |
4 | #include <linux/mm.h> | |
4e950f6f | 5 | #include <linux/fs.h> |
1da177e4 | 6 | #include <linux/smp.h> |
1da177e4 LT |
7 | #include <linux/sem.h> |
8 | #include <linux/msg.h> | |
9 | #include <linux/shm.h> | |
10 | #include <linux/stat.h> | |
11 | #include <linux/mman.h> | |
12 | #include <linux/file.h> | |
13 | #include <linux/utsname.h> | |
14 | #include <linux/personality.h> | |
cc503c1b | 15 | #include <linux/random.h> |
e9c8abb6 | 16 | #include <linux/uaccess.h> |
910b2c51 | 17 | #include <linux/elf.h> |
1da177e4 | 18 | |
1da177e4 | 19 | #include <asm/ia32.h> |
bbc1f698 | 20 | #include <asm/syscalls.h> |
1da177e4 | 21 | |
dfb09f9b BP |
22 | /* |
23 | * Align a virtual address to avoid aliasing in the I$ on AMD F15h. | |
dfb09f9b | 24 | */ |
f9902472 | 25 | static unsigned long get_align_mask(void) |
dfb09f9b | 26 | { |
dfb09f9b BP |
27 | /* handle 32- and 64-bit case with a single conditional */ |
28 | if (va_align.flags < 0 || !(va_align.flags & (2 - mmap_is_ia32()))) | |
f9902472 | 29 | return 0; |
dfb09f9b BP |
30 | |
31 | if (!(current->flags & PF_RANDOMIZE)) | |
f9902472 | 32 | return 0; |
dfb09f9b | 33 | |
f9902472 ML |
34 | return va_align.mask; |
35 | } | |
dfb09f9b | 36 | |
4e26d11f HMG |
37 | /* |
38 | * To avoid aliasing in the I$ on AMD F15h, the bits defined by the | |
39 | * va_align.bits, [12:upper_bit), are set to a random value instead of | |
40 | * zeroing them. This random value is computed once per boot. This form | |
41 | * of ASLR is known as "per-boot ASLR". | |
42 | * | |
43 | * To achieve this, the random value is added to the info.align_offset | |
44 | * value before calling vm_unmapped_area() or ORed directly to the | |
45 | * address. | |
46 | */ | |
47 | static unsigned long get_align_bits(void) | |
48 | { | |
49 | return va_align.bits & get_align_mask(); | |
50 | } | |
51 | ||
f9902472 ML |
52 | unsigned long align_vdso_addr(unsigned long addr) |
53 | { | |
54 | unsigned long align_mask = get_align_mask(); | |
4e26d11f HMG |
55 | addr = (addr + align_mask) & ~align_mask; |
56 | return addr | get_align_bits(); | |
dfb09f9b BP |
57 | } |
58 | ||
59 | static int __init control_va_addr_alignment(char *str) | |
60 | { | |
61 | /* guard against enabling this on other CPU families */ | |
62 | if (va_align.flags < 0) | |
63 | return 1; | |
64 | ||
65 | if (*str == 0) | |
66 | return 1; | |
67 | ||
68 | if (*str == '=') | |
69 | str++; | |
70 | ||
71 | if (!strcmp(str, "32")) | |
72 | va_align.flags = ALIGN_VA_32; | |
73 | else if (!strcmp(str, "64")) | |
74 | va_align.flags = ALIGN_VA_64; | |
75 | else if (!strcmp(str, "off")) | |
76 | va_align.flags = 0; | |
77 | else if (!strcmp(str, "on")) | |
78 | va_align.flags = ALIGN_VA_32 | ALIGN_VA_64; | |
79 | else | |
80 | return 0; | |
81 | ||
82 | return 1; | |
83 | } | |
84 | __setup("align_va_addr", control_va_addr_alignment); | |
85 | ||
0ac676fb JB |
86 | SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len, |
87 | unsigned long, prot, unsigned long, flags, | |
88 | unsigned long, fd, unsigned long, off) | |
1da177e4 LT |
89 | { |
90 | long error; | |
1da177e4 LT |
91 | error = -EINVAL; |
92 | if (off & ~PAGE_MASK) | |
93 | goto out; | |
94 | ||
f8b72560 | 95 | error = sys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT); |
1da177e4 LT |
96 | out: |
97 | return error; | |
98 | } | |
99 | ||
100 | static void find_start_end(unsigned long flags, unsigned long *begin, | |
101 | unsigned long *end) | |
102 | { | |
6bd33008 | 103 | if (!test_thread_flag(TIF_ADDR32) && (flags & MAP_32BIT)) { |
cc503c1b | 104 | unsigned long new_begin; |
1da177e4 LT |
105 | /* This is usually used needed to map code in small |
106 | model, so it needs to be in the first 31bit. Limit | |
107 | it to that. This means we need to move the | |
108 | unmapped base down for this case. This can give | |
109 | conflicts with the heap, but we assume that glibc | |
110 | malloc knows how to fall back to mmap. Give it 1GB | |
e9c8abb6 GP |
111 | of playground for now. -AK */ |
112 | *begin = 0x40000000; | |
113 | *end = 0x80000000; | |
cc503c1b JK |
114 | if (current->flags & PF_RANDOMIZE) { |
115 | new_begin = randomize_range(*begin, *begin + 0x02000000, 0); | |
116 | if (new_begin) | |
117 | *begin = new_begin; | |
118 | } | |
84929801 | 119 | } else { |
41aacc1e | 120 | *begin = current->mm->mmap_legacy_base; |
e9c8abb6 | 121 | *end = TASK_SIZE; |
84929801 | 122 | } |
e9c8abb6 | 123 | } |
1da177e4 LT |
124 | |
125 | unsigned long | |
126 | arch_get_unmapped_area(struct file *filp, unsigned long addr, | |
127 | unsigned long len, unsigned long pgoff, unsigned long flags) | |
128 | { | |
129 | struct mm_struct *mm = current->mm; | |
130 | struct vm_area_struct *vma; | |
f9902472 | 131 | struct vm_unmapped_area_info info; |
1da177e4 | 132 | unsigned long begin, end; |
e9c8abb6 | 133 | |
11300a64 BH |
134 | if (flags & MAP_FIXED) |
135 | return addr; | |
136 | ||
e9c8abb6 | 137 | find_start_end(flags, &begin, &end); |
1da177e4 LT |
138 | |
139 | if (len > end) | |
140 | return -ENOMEM; | |
141 | ||
142 | if (addr) { | |
143 | addr = PAGE_ALIGN(addr); | |
144 | vma = find_vma(mm, addr); | |
145 | if (end - len >= addr && | |
146 | (!vma || addr + len <= vma->vm_start)) | |
147 | return addr; | |
148 | } | |
1363c3cd | 149 | |
f9902472 ML |
150 | info.flags = 0; |
151 | info.length = len; | |
152 | info.low_limit = begin; | |
153 | info.high_limit = end; | |
4e26d11f | 154 | info.align_mask = 0; |
7d025059 | 155 | info.align_offset = pgoff << PAGE_SHIFT; |
4e26d11f HMG |
156 | if (filp) { |
157 | info.align_mask = get_align_mask(); | |
158 | info.align_offset += get_align_bits(); | |
159 | } | |
f9902472 | 160 | return vm_unmapped_area(&info); |
1da177e4 LT |
161 | } |
162 | ||
cc503c1b JK |
163 | unsigned long |
164 | arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, | |
165 | const unsigned long len, const unsigned long pgoff, | |
166 | const unsigned long flags) | |
167 | { | |
168 | struct vm_area_struct *vma; | |
169 | struct mm_struct *mm = current->mm; | |
f9902472 ML |
170 | unsigned long addr = addr0; |
171 | struct vm_unmapped_area_info info; | |
cc503c1b JK |
172 | |
173 | /* requested length too big for entire address space */ | |
174 | if (len > TASK_SIZE) | |
175 | return -ENOMEM; | |
176 | ||
177 | if (flags & MAP_FIXED) | |
178 | return addr; | |
179 | ||
e3e81aca | 180 | /* for MAP_32BIT mappings we force the legacy mmap base */ |
6bd33008 | 181 | if (!test_thread_flag(TIF_ADDR32) && (flags & MAP_32BIT)) |
cc503c1b JK |
182 | goto bottomup; |
183 | ||
184 | /* requesting a specific address */ | |
185 | if (addr) { | |
186 | addr = PAGE_ALIGN(addr); | |
187 | vma = find_vma(mm, addr); | |
188 | if (TASK_SIZE - len >= addr && | |
189 | (!vma || addr + len <= vma->vm_start)) | |
190 | return addr; | |
191 | } | |
192 | ||
f9902472 ML |
193 | info.flags = VM_UNMAPPED_AREA_TOPDOWN; |
194 | info.length = len; | |
195 | info.low_limit = PAGE_SIZE; | |
196 | info.high_limit = mm->mmap_base; | |
4e26d11f | 197 | info.align_mask = 0; |
7d025059 | 198 | info.align_offset = pgoff << PAGE_SHIFT; |
4e26d11f HMG |
199 | if (filp) { |
200 | info.align_mask = get_align_mask(); | |
201 | info.align_offset += get_align_bits(); | |
202 | } | |
f9902472 ML |
203 | addr = vm_unmapped_area(&info); |
204 | if (!(addr & ~PAGE_MASK)) | |
205 | return addr; | |
206 | VM_BUG_ON(addr != -ENOMEM); | |
b716ad95 | 207 | |
cc503c1b JK |
208 | bottomup: |
209 | /* | |
210 | * A failed mmap() very likely causes application failure, | |
211 | * so fall back to the bottom-up function here. This scenario | |
212 | * can happen with large stack limits and large mmap() | |
213 | * allocations. | |
214 | */ | |
f9902472 | 215 | return arch_get_unmapped_area(filp, addr0, len, pgoff, flags); |
cc503c1b | 216 | } |