Commit | Line | Data |
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16d69265 | 1 | #include <linux/mm.h> |
30992c97 MM |
2 | #include <linux/slab.h> |
3 | #include <linux/string.h> | |
4 | #include <linux/module.h> | |
96840aa0 | 5 | #include <linux/err.h> |
3b8f14b4 | 6 | #include <linux/sched.h> |
96840aa0 | 7 | #include <asm/uaccess.h> |
30992c97 MM |
8 | |
9 | /** | |
30992c97 | 10 | * kstrdup - allocate space for and copy an existing string |
30992c97 MM |
11 | * @s: the string to duplicate |
12 | * @gfp: the GFP mask used in the kmalloc() call when allocating memory | |
13 | */ | |
14 | char *kstrdup(const char *s, gfp_t gfp) | |
15 | { | |
16 | size_t len; | |
17 | char *buf; | |
18 | ||
19 | if (!s) | |
20 | return NULL; | |
21 | ||
22 | len = strlen(s) + 1; | |
1d2c8eea | 23 | buf = kmalloc_track_caller(len, gfp); |
30992c97 MM |
24 | if (buf) |
25 | memcpy(buf, s, len); | |
26 | return buf; | |
27 | } | |
28 | EXPORT_SYMBOL(kstrdup); | |
96840aa0 | 29 | |
1e66df3e JF |
30 | /** |
31 | * kstrndup - allocate space for and copy an existing string | |
32 | * @s: the string to duplicate | |
33 | * @max: read at most @max chars from @s | |
34 | * @gfp: the GFP mask used in the kmalloc() call when allocating memory | |
35 | */ | |
36 | char *kstrndup(const char *s, size_t max, gfp_t gfp) | |
37 | { | |
38 | size_t len; | |
39 | char *buf; | |
40 | ||
41 | if (!s) | |
42 | return NULL; | |
43 | ||
44 | len = strnlen(s, max); | |
45 | buf = kmalloc_track_caller(len+1, gfp); | |
46 | if (buf) { | |
47 | memcpy(buf, s, len); | |
48 | buf[len] = '\0'; | |
49 | } | |
50 | return buf; | |
51 | } | |
52 | EXPORT_SYMBOL(kstrndup); | |
53 | ||
1a2f67b4 AD |
54 | /** |
55 | * kmemdup - duplicate region of memory | |
56 | * | |
57 | * @src: memory region to duplicate | |
58 | * @len: memory region length | |
59 | * @gfp: GFP mask to use | |
60 | */ | |
61 | void *kmemdup(const void *src, size_t len, gfp_t gfp) | |
62 | { | |
63 | void *p; | |
64 | ||
1d2c8eea | 65 | p = kmalloc_track_caller(len, gfp); |
1a2f67b4 AD |
66 | if (p) |
67 | memcpy(p, src, len); | |
68 | return p; | |
69 | } | |
70 | EXPORT_SYMBOL(kmemdup); | |
71 | ||
ef2ad80c | 72 | /** |
93bc4e89 | 73 | * __krealloc - like krealloc() but don't free @p. |
ef2ad80c CL |
74 | * @p: object to reallocate memory for. |
75 | * @new_size: how many bytes of memory are required. | |
76 | * @flags: the type of memory to allocate. | |
77 | * | |
93bc4e89 PE |
78 | * This function is like krealloc() except it never frees the originally |
79 | * allocated buffer. Use this if you don't want to free the buffer immediately | |
80 | * like, for example, with RCU. | |
ef2ad80c | 81 | */ |
93bc4e89 | 82 | void *__krealloc(const void *p, size_t new_size, gfp_t flags) |
ef2ad80c CL |
83 | { |
84 | void *ret; | |
ef8b4520 | 85 | size_t ks = 0; |
ef2ad80c | 86 | |
93bc4e89 | 87 | if (unlikely(!new_size)) |
6cb8f913 | 88 | return ZERO_SIZE_PTR; |
ef2ad80c | 89 | |
ef8b4520 CL |
90 | if (p) |
91 | ks = ksize(p); | |
92 | ||
ef2ad80c CL |
93 | if (ks >= new_size) |
94 | return (void *)p; | |
95 | ||
96 | ret = kmalloc_track_caller(new_size, flags); | |
93bc4e89 | 97 | if (ret && p) |
be21f0ab | 98 | memcpy(ret, p, ks); |
93bc4e89 PE |
99 | |
100 | return ret; | |
101 | } | |
102 | EXPORT_SYMBOL(__krealloc); | |
103 | ||
104 | /** | |
105 | * krealloc - reallocate memory. The contents will remain unchanged. | |
106 | * @p: object to reallocate memory for. | |
107 | * @new_size: how many bytes of memory are required. | |
108 | * @flags: the type of memory to allocate. | |
109 | * | |
110 | * The contents of the object pointed to are preserved up to the | |
111 | * lesser of the new and old sizes. If @p is %NULL, krealloc() | |
112 | * behaves exactly like kmalloc(). If @size is 0 and @p is not a | |
113 | * %NULL pointer, the object pointed to is freed. | |
114 | */ | |
115 | void *krealloc(const void *p, size_t new_size, gfp_t flags) | |
116 | { | |
117 | void *ret; | |
118 | ||
119 | if (unlikely(!new_size)) { | |
ef2ad80c | 120 | kfree(p); |
93bc4e89 | 121 | return ZERO_SIZE_PTR; |
ef2ad80c | 122 | } |
93bc4e89 PE |
123 | |
124 | ret = __krealloc(p, new_size, flags); | |
125 | if (ret && p != ret) | |
126 | kfree(p); | |
127 | ||
ef2ad80c CL |
128 | return ret; |
129 | } | |
130 | EXPORT_SYMBOL(krealloc); | |
131 | ||
3ef0e5ba JW |
132 | /** |
133 | * kzfree - like kfree but zero memory | |
134 | * @p: object to free memory of | |
135 | * | |
136 | * The memory of the object @p points to is zeroed before freed. | |
137 | * If @p is %NULL, kzfree() does nothing. | |
138 | */ | |
139 | void kzfree(const void *p) | |
140 | { | |
141 | size_t ks; | |
142 | void *mem = (void *)p; | |
143 | ||
144 | if (unlikely(ZERO_OR_NULL_PTR(mem))) | |
145 | return; | |
146 | ks = ksize(mem); | |
147 | memset(mem, 0, ks); | |
148 | kfree(mem); | |
149 | } | |
150 | EXPORT_SYMBOL(kzfree); | |
151 | ||
96840aa0 DA |
152 | /* |
153 | * strndup_user - duplicate an existing string from user space | |
96840aa0 DA |
154 | * @s: The string to duplicate |
155 | * @n: Maximum number of bytes to copy, including the trailing NUL. | |
156 | */ | |
157 | char *strndup_user(const char __user *s, long n) | |
158 | { | |
159 | char *p; | |
160 | long length; | |
161 | ||
162 | length = strnlen_user(s, n); | |
163 | ||
164 | if (!length) | |
165 | return ERR_PTR(-EFAULT); | |
166 | ||
167 | if (length > n) | |
168 | return ERR_PTR(-EINVAL); | |
169 | ||
170 | p = kmalloc(length, GFP_KERNEL); | |
171 | ||
172 | if (!p) | |
173 | return ERR_PTR(-ENOMEM); | |
174 | ||
175 | if (copy_from_user(p, s, length)) { | |
176 | kfree(p); | |
177 | return ERR_PTR(-EFAULT); | |
178 | } | |
179 | ||
180 | p[length - 1] = '\0'; | |
181 | ||
182 | return p; | |
183 | } | |
184 | EXPORT_SYMBOL(strndup_user); | |
16d69265 AM |
185 | |
186 | #ifndef HAVE_ARCH_PICK_MMAP_LAYOUT | |
187 | void arch_pick_mmap_layout(struct mm_struct *mm) | |
188 | { | |
189 | mm->mmap_base = TASK_UNMAPPED_BASE; | |
190 | mm->get_unmapped_area = arch_get_unmapped_area; | |
191 | mm->unmap_area = arch_unmap_area; | |
192 | } | |
193 | #endif | |
912985dc RR |
194 | |
195 | int __attribute__((weak)) get_user_pages_fast(unsigned long start, | |
196 | int nr_pages, int write, struct page **pages) | |
197 | { | |
198 | struct mm_struct *mm = current->mm; | |
199 | int ret; | |
200 | ||
201 | down_read(&mm->mmap_sem); | |
202 | ret = get_user_pages(current, mm, start, nr_pages, | |
203 | write, 0, pages, NULL); | |
204 | up_read(&mm->mmap_sem); | |
205 | ||
206 | return ret; | |
207 | } | |
208 | EXPORT_SYMBOL_GPL(get_user_pages_fast); |