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> |
ca2b84cb | 7 | #include <linux/tracepoint.h> |
96840aa0 | 8 | #include <asm/uaccess.h> |
30992c97 MM |
9 | |
10 | /** | |
30992c97 | 11 | * kstrdup - allocate space for and copy an existing string |
30992c97 MM |
12 | * @s: the string to duplicate |
13 | * @gfp: the GFP mask used in the kmalloc() call when allocating memory | |
14 | */ | |
15 | char *kstrdup(const char *s, gfp_t gfp) | |
16 | { | |
17 | size_t len; | |
18 | char *buf; | |
19 | ||
20 | if (!s) | |
21 | return NULL; | |
22 | ||
23 | len = strlen(s) + 1; | |
1d2c8eea | 24 | buf = kmalloc_track_caller(len, gfp); |
30992c97 MM |
25 | if (buf) |
26 | memcpy(buf, s, len); | |
27 | return buf; | |
28 | } | |
29 | EXPORT_SYMBOL(kstrdup); | |
96840aa0 | 30 | |
1e66df3e JF |
31 | /** |
32 | * kstrndup - allocate space for and copy an existing string | |
33 | * @s: the string to duplicate | |
34 | * @max: read at most @max chars from @s | |
35 | * @gfp: the GFP mask used in the kmalloc() call when allocating memory | |
36 | */ | |
37 | char *kstrndup(const char *s, size_t max, gfp_t gfp) | |
38 | { | |
39 | size_t len; | |
40 | char *buf; | |
41 | ||
42 | if (!s) | |
43 | return NULL; | |
44 | ||
45 | len = strnlen(s, max); | |
46 | buf = kmalloc_track_caller(len+1, gfp); | |
47 | if (buf) { | |
48 | memcpy(buf, s, len); | |
49 | buf[len] = '\0'; | |
50 | } | |
51 | return buf; | |
52 | } | |
53 | EXPORT_SYMBOL(kstrndup); | |
54 | ||
1a2f67b4 AD |
55 | /** |
56 | * kmemdup - duplicate region of memory | |
57 | * | |
58 | * @src: memory region to duplicate | |
59 | * @len: memory region length | |
60 | * @gfp: GFP mask to use | |
61 | */ | |
62 | void *kmemdup(const void *src, size_t len, gfp_t gfp) | |
63 | { | |
64 | void *p; | |
65 | ||
1d2c8eea | 66 | p = kmalloc_track_caller(len, gfp); |
1a2f67b4 AD |
67 | if (p) |
68 | memcpy(p, src, len); | |
69 | return p; | |
70 | } | |
71 | EXPORT_SYMBOL(kmemdup); | |
72 | ||
610a77e0 LZ |
73 | /** |
74 | * memdup_user - duplicate memory region from user space | |
75 | * | |
76 | * @src: source address in user space | |
77 | * @len: number of bytes to copy | |
78 | * | |
79 | * Returns an ERR_PTR() on failure. | |
80 | */ | |
81 | void *memdup_user(const void __user *src, size_t len) | |
82 | { | |
83 | void *p; | |
84 | ||
85 | /* | |
86 | * Always use GFP_KERNEL, since copy_from_user() can sleep and | |
87 | * cause pagefault, which makes it pointless to use GFP_NOFS | |
88 | * or GFP_ATOMIC. | |
89 | */ | |
90 | p = kmalloc_track_caller(len, GFP_KERNEL); | |
91 | if (!p) | |
92 | return ERR_PTR(-ENOMEM); | |
93 | ||
94 | if (copy_from_user(p, src, len)) { | |
95 | kfree(p); | |
96 | return ERR_PTR(-EFAULT); | |
97 | } | |
98 | ||
99 | return p; | |
100 | } | |
101 | EXPORT_SYMBOL(memdup_user); | |
102 | ||
ef2ad80c | 103 | /** |
93bc4e89 | 104 | * __krealloc - like krealloc() but don't free @p. |
ef2ad80c CL |
105 | * @p: object to reallocate memory for. |
106 | * @new_size: how many bytes of memory are required. | |
107 | * @flags: the type of memory to allocate. | |
108 | * | |
93bc4e89 PE |
109 | * This function is like krealloc() except it never frees the originally |
110 | * allocated buffer. Use this if you don't want to free the buffer immediately | |
111 | * like, for example, with RCU. | |
ef2ad80c | 112 | */ |
93bc4e89 | 113 | void *__krealloc(const void *p, size_t new_size, gfp_t flags) |
ef2ad80c CL |
114 | { |
115 | void *ret; | |
ef8b4520 | 116 | size_t ks = 0; |
ef2ad80c | 117 | |
93bc4e89 | 118 | if (unlikely(!new_size)) |
6cb8f913 | 119 | return ZERO_SIZE_PTR; |
ef2ad80c | 120 | |
ef8b4520 CL |
121 | if (p) |
122 | ks = ksize(p); | |
123 | ||
ef2ad80c CL |
124 | if (ks >= new_size) |
125 | return (void *)p; | |
126 | ||
127 | ret = kmalloc_track_caller(new_size, flags); | |
93bc4e89 | 128 | if (ret && p) |
be21f0ab | 129 | memcpy(ret, p, ks); |
93bc4e89 PE |
130 | |
131 | return ret; | |
132 | } | |
133 | EXPORT_SYMBOL(__krealloc); | |
134 | ||
135 | /** | |
136 | * krealloc - reallocate memory. The contents will remain unchanged. | |
137 | * @p: object to reallocate memory for. | |
138 | * @new_size: how many bytes of memory are required. | |
139 | * @flags: the type of memory to allocate. | |
140 | * | |
141 | * The contents of the object pointed to are preserved up to the | |
142 | * lesser of the new and old sizes. If @p is %NULL, krealloc() | |
143 | * behaves exactly like kmalloc(). If @size is 0 and @p is not a | |
144 | * %NULL pointer, the object pointed to is freed. | |
145 | */ | |
146 | void *krealloc(const void *p, size_t new_size, gfp_t flags) | |
147 | { | |
148 | void *ret; | |
149 | ||
150 | if (unlikely(!new_size)) { | |
ef2ad80c | 151 | kfree(p); |
93bc4e89 | 152 | return ZERO_SIZE_PTR; |
ef2ad80c | 153 | } |
93bc4e89 PE |
154 | |
155 | ret = __krealloc(p, new_size, flags); | |
156 | if (ret && p != ret) | |
157 | kfree(p); | |
158 | ||
ef2ad80c CL |
159 | return ret; |
160 | } | |
161 | EXPORT_SYMBOL(krealloc); | |
162 | ||
3ef0e5ba JW |
163 | /** |
164 | * kzfree - like kfree but zero memory | |
165 | * @p: object to free memory of | |
166 | * | |
167 | * The memory of the object @p points to is zeroed before freed. | |
168 | * If @p is %NULL, kzfree() does nothing. | |
169 | */ | |
170 | void kzfree(const void *p) | |
171 | { | |
172 | size_t ks; | |
173 | void *mem = (void *)p; | |
174 | ||
175 | if (unlikely(ZERO_OR_NULL_PTR(mem))) | |
176 | return; | |
177 | ks = ksize(mem); | |
178 | memset(mem, 0, ks); | |
179 | kfree(mem); | |
180 | } | |
181 | EXPORT_SYMBOL(kzfree); | |
182 | ||
96840aa0 DA |
183 | /* |
184 | * strndup_user - duplicate an existing string from user space | |
96840aa0 DA |
185 | * @s: The string to duplicate |
186 | * @n: Maximum number of bytes to copy, including the trailing NUL. | |
187 | */ | |
188 | char *strndup_user(const char __user *s, long n) | |
189 | { | |
190 | char *p; | |
191 | long length; | |
192 | ||
193 | length = strnlen_user(s, n); | |
194 | ||
195 | if (!length) | |
196 | return ERR_PTR(-EFAULT); | |
197 | ||
198 | if (length > n) | |
199 | return ERR_PTR(-EINVAL); | |
200 | ||
201 | p = kmalloc(length, GFP_KERNEL); | |
202 | ||
203 | if (!p) | |
204 | return ERR_PTR(-ENOMEM); | |
205 | ||
206 | if (copy_from_user(p, s, length)) { | |
207 | kfree(p); | |
208 | return ERR_PTR(-EFAULT); | |
209 | } | |
210 | ||
211 | p[length - 1] = '\0'; | |
212 | ||
213 | return p; | |
214 | } | |
215 | EXPORT_SYMBOL(strndup_user); | |
16d69265 AM |
216 | |
217 | #ifndef HAVE_ARCH_PICK_MMAP_LAYOUT | |
218 | void arch_pick_mmap_layout(struct mm_struct *mm) | |
219 | { | |
220 | mm->mmap_base = TASK_UNMAPPED_BASE; | |
221 | mm->get_unmapped_area = arch_get_unmapped_area; | |
222 | mm->unmap_area = arch_unmap_area; | |
223 | } | |
224 | #endif | |
912985dc | 225 | |
9de100d0 AG |
226 | /** |
227 | * get_user_pages_fast() - pin user pages in memory | |
228 | * @start: starting user address | |
229 | * @nr_pages: number of pages from start to pin | |
230 | * @write: whether pages will be written to | |
231 | * @pages: array that receives pointers to the pages pinned. | |
232 | * Should be at least nr_pages long. | |
233 | * | |
234 | * Attempt to pin user pages in memory without taking mm->mmap_sem. | |
235 | * If not successful, it will fall back to taking the lock and | |
236 | * calling get_user_pages(). | |
237 | * | |
238 | * Returns number of pages pinned. This may be fewer than the number | |
239 | * requested. If nr_pages is 0 or negative, returns 0. If no pages | |
240 | * were pinned, returns -errno. | |
241 | */ | |
912985dc RR |
242 | int __attribute__((weak)) get_user_pages_fast(unsigned long start, |
243 | int nr_pages, int write, struct page **pages) | |
244 | { | |
245 | struct mm_struct *mm = current->mm; | |
246 | int ret; | |
247 | ||
248 | down_read(&mm->mmap_sem); | |
249 | ret = get_user_pages(current, mm, start, nr_pages, | |
250 | write, 0, pages, NULL); | |
251 | up_read(&mm->mmap_sem); | |
252 | ||
253 | return ret; | |
254 | } | |
255 | EXPORT_SYMBOL_GPL(get_user_pages_fast); | |
ca2b84cb EGM |
256 | |
257 | /* Tracepoints definitions. */ | |
258 | DEFINE_TRACE(kmalloc); | |
259 | DEFINE_TRACE(kmem_cache_alloc); | |
260 | DEFINE_TRACE(kmalloc_node); | |
261 | DEFINE_TRACE(kmem_cache_alloc_node); | |
262 | DEFINE_TRACE(kfree); | |
263 | DEFINE_TRACE(kmem_cache_free); | |
264 | ||
265 | EXPORT_TRACEPOINT_SYMBOL(kmalloc); | |
266 | EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc); | |
267 | EXPORT_TRACEPOINT_SYMBOL(kmalloc_node); | |
268 | EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node); | |
269 | EXPORT_TRACEPOINT_SYMBOL(kfree); | |
270 | EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free); |