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 DA |
5 | #include <linux/err.h> |
6 | #include <asm/uaccess.h> | |
30992c97 MM |
7 | |
8 | /** | |
30992c97 | 9 | * kstrdup - allocate space for and copy an existing string |
30992c97 MM |
10 | * @s: the string to duplicate |
11 | * @gfp: the GFP mask used in the kmalloc() call when allocating memory | |
12 | */ | |
13 | char *kstrdup(const char *s, gfp_t gfp) | |
14 | { | |
15 | size_t len; | |
16 | char *buf; | |
17 | ||
18 | if (!s) | |
19 | return NULL; | |
20 | ||
21 | len = strlen(s) + 1; | |
1d2c8eea | 22 | buf = kmalloc_track_caller(len, gfp); |
30992c97 MM |
23 | if (buf) |
24 | memcpy(buf, s, len); | |
25 | return buf; | |
26 | } | |
27 | EXPORT_SYMBOL(kstrdup); | |
96840aa0 | 28 | |
1e66df3e JF |
29 | /** |
30 | * kstrndup - allocate space for and copy an existing string | |
31 | * @s: the string to duplicate | |
32 | * @max: read at most @max chars from @s | |
33 | * @gfp: the GFP mask used in the kmalloc() call when allocating memory | |
34 | */ | |
35 | char *kstrndup(const char *s, size_t max, gfp_t gfp) | |
36 | { | |
37 | size_t len; | |
38 | char *buf; | |
39 | ||
40 | if (!s) | |
41 | return NULL; | |
42 | ||
43 | len = strnlen(s, max); | |
44 | buf = kmalloc_track_caller(len+1, gfp); | |
45 | if (buf) { | |
46 | memcpy(buf, s, len); | |
47 | buf[len] = '\0'; | |
48 | } | |
49 | return buf; | |
50 | } | |
51 | EXPORT_SYMBOL(kstrndup); | |
52 | ||
1a2f67b4 AD |
53 | /** |
54 | * kmemdup - duplicate region of memory | |
55 | * | |
56 | * @src: memory region to duplicate | |
57 | * @len: memory region length | |
58 | * @gfp: GFP mask to use | |
59 | */ | |
60 | void *kmemdup(const void *src, size_t len, gfp_t gfp) | |
61 | { | |
62 | void *p; | |
63 | ||
1d2c8eea | 64 | p = kmalloc_track_caller(len, gfp); |
1a2f67b4 AD |
65 | if (p) |
66 | memcpy(p, src, len); | |
67 | return p; | |
68 | } | |
69 | EXPORT_SYMBOL(kmemdup); | |
70 | ||
ef2ad80c CL |
71 | /** |
72 | * krealloc - reallocate memory. The contents will remain unchanged. | |
73 | * @p: object to reallocate memory for. | |
74 | * @new_size: how many bytes of memory are required. | |
75 | * @flags: the type of memory to allocate. | |
76 | * | |
77 | * The contents of the object pointed to are preserved up to the | |
78 | * lesser of the new and old sizes. If @p is %NULL, krealloc() | |
79 | * behaves exactly like kmalloc(). If @size is 0 and @p is not a | |
80 | * %NULL pointer, the object pointed to is freed. | |
81 | */ | |
82 | void *krealloc(const void *p, size_t new_size, gfp_t flags) | |
83 | { | |
84 | void *ret; | |
ef8b4520 | 85 | size_t ks = 0; |
ef2ad80c CL |
86 | |
87 | if (unlikely(!new_size)) { | |
88 | kfree(p); | |
6cb8f913 | 89 | return ZERO_SIZE_PTR; |
ef2ad80c CL |
90 | } |
91 | ||
ef8b4520 CL |
92 | if (p) |
93 | ks = ksize(p); | |
94 | ||
ef2ad80c CL |
95 | if (ks >= new_size) |
96 | return (void *)p; | |
97 | ||
98 | ret = kmalloc_track_caller(new_size, flags); | |
be21f0ab AB |
99 | if (ret && p) { |
100 | memcpy(ret, p, ks); | |
ef2ad80c CL |
101 | kfree(p); |
102 | } | |
103 | return ret; | |
104 | } | |
105 | EXPORT_SYMBOL(krealloc); | |
106 | ||
96840aa0 DA |
107 | /* |
108 | * strndup_user - duplicate an existing string from user space | |
96840aa0 DA |
109 | * @s: The string to duplicate |
110 | * @n: Maximum number of bytes to copy, including the trailing NUL. | |
111 | */ | |
112 | char *strndup_user(const char __user *s, long n) | |
113 | { | |
114 | char *p; | |
115 | long length; | |
116 | ||
117 | length = strnlen_user(s, n); | |
118 | ||
119 | if (!length) | |
120 | return ERR_PTR(-EFAULT); | |
121 | ||
122 | if (length > n) | |
123 | return ERR_PTR(-EINVAL); | |
124 | ||
125 | p = kmalloc(length, GFP_KERNEL); | |
126 | ||
127 | if (!p) | |
128 | return ERR_PTR(-ENOMEM); | |
129 | ||
130 | if (copy_from_user(p, s, length)) { | |
131 | kfree(p); | |
132 | return ERR_PTR(-EFAULT); | |
133 | } | |
134 | ||
135 | p[length - 1] = '\0'; | |
136 | ||
137 | return p; | |
138 | } | |
139 | EXPORT_SYMBOL(strndup_user); | |
16d69265 AM |
140 | |
141 | #ifndef HAVE_ARCH_PICK_MMAP_LAYOUT | |
142 | void arch_pick_mmap_layout(struct mm_struct *mm) | |
143 | { | |
144 | mm->mmap_base = TASK_UNMAPPED_BASE; | |
145 | mm->get_unmapped_area = arch_get_unmapped_area; | |
146 | mm->unmap_area = arch_unmap_area; | |
147 | } | |
148 | #endif |