Root/
1 | #include <linux/mm.h> |
2 | #include <linux/slab.h> |
3 | #include <linux/string.h> |
4 | #include <linux/export.h> |
5 | #include <linux/err.h> |
6 | #include <linux/sched.h> |
7 | #include <asm/uaccess.h> |
8 | |
9 | #include "internal.h" |
10 | |
11 | #define CREATE_TRACE_POINTS |
12 | #include <trace/events/kmem.h> |
13 | |
14 | /** |
15 | * kstrdup - allocate space for and copy an existing string |
16 | * @s: the string to duplicate |
17 | * @gfp: the GFP mask used in the kmalloc() call when allocating memory |
18 | */ |
19 | char *kstrdup(const char *s, gfp_t gfp) |
20 | { |
21 | size_t len; |
22 | char *buf; |
23 | |
24 | if (!s) |
25 | return NULL; |
26 | |
27 | len = strlen(s) + 1; |
28 | buf = kmalloc_track_caller(len, gfp); |
29 | if (buf) |
30 | memcpy(buf, s, len); |
31 | return buf; |
32 | } |
33 | EXPORT_SYMBOL(kstrdup); |
34 | |
35 | /** |
36 | * kstrndup - allocate space for and copy an existing string |
37 | * @s: the string to duplicate |
38 | * @max: read at most @max chars from @s |
39 | * @gfp: the GFP mask used in the kmalloc() call when allocating memory |
40 | */ |
41 | char *kstrndup(const char *s, size_t max, gfp_t gfp) |
42 | { |
43 | size_t len; |
44 | char *buf; |
45 | |
46 | if (!s) |
47 | return NULL; |
48 | |
49 | len = strnlen(s, max); |
50 | buf = kmalloc_track_caller(len+1, gfp); |
51 | if (buf) { |
52 | memcpy(buf, s, len); |
53 | buf[len] = '\0'; |
54 | } |
55 | return buf; |
56 | } |
57 | EXPORT_SYMBOL(kstrndup); |
58 | |
59 | /** |
60 | * kmemdup - duplicate region of memory |
61 | * |
62 | * @src: memory region to duplicate |
63 | * @len: memory region length |
64 | * @gfp: GFP mask to use |
65 | */ |
66 | void *kmemdup(const void *src, size_t len, gfp_t gfp) |
67 | { |
68 | void *p; |
69 | |
70 | p = kmalloc_track_caller(len, gfp); |
71 | if (p) |
72 | memcpy(p, src, len); |
73 | return p; |
74 | } |
75 | EXPORT_SYMBOL(kmemdup); |
76 | |
77 | /** |
78 | * memdup_user - duplicate memory region from user space |
79 | * |
80 | * @src: source address in user space |
81 | * @len: number of bytes to copy |
82 | * |
83 | * Returns an ERR_PTR() on failure. |
84 | */ |
85 | void *memdup_user(const void __user *src, size_t len) |
86 | { |
87 | void *p; |
88 | |
89 | /* |
90 | * Always use GFP_KERNEL, since copy_from_user() can sleep and |
91 | * cause pagefault, which makes it pointless to use GFP_NOFS |
92 | * or GFP_ATOMIC. |
93 | */ |
94 | p = kmalloc_track_caller(len, GFP_KERNEL); |
95 | if (!p) |
96 | return ERR_PTR(-ENOMEM); |
97 | |
98 | if (copy_from_user(p, src, len)) { |
99 | kfree(p); |
100 | return ERR_PTR(-EFAULT); |
101 | } |
102 | |
103 | return p; |
104 | } |
105 | EXPORT_SYMBOL(memdup_user); |
106 | |
107 | /** |
108 | * __krealloc - like krealloc() but don't free @p. |
109 | * @p: object to reallocate memory for. |
110 | * @new_size: how many bytes of memory are required. |
111 | * @flags: the type of memory to allocate. |
112 | * |
113 | * This function is like krealloc() except it never frees the originally |
114 | * allocated buffer. Use this if you don't want to free the buffer immediately |
115 | * like, for example, with RCU. |
116 | */ |
117 | void *__krealloc(const void *p, size_t new_size, gfp_t flags) |
118 | { |
119 | void *ret; |
120 | size_t ks = 0; |
121 | |
122 | if (unlikely(!new_size)) |
123 | return ZERO_SIZE_PTR; |
124 | |
125 | if (p) |
126 | ks = ksize(p); |
127 | |
128 | if (ks >= new_size) |
129 | return (void *)p; |
130 | |
131 | ret = kmalloc_track_caller(new_size, flags); |
132 | if (ret && p) |
133 | memcpy(ret, p, ks); |
134 | |
135 | return ret; |
136 | } |
137 | EXPORT_SYMBOL(__krealloc); |
138 | |
139 | /** |
140 | * krealloc - reallocate memory. The contents will remain unchanged. |
141 | * @p: object to reallocate memory for. |
142 | * @new_size: how many bytes of memory are required. |
143 | * @flags: the type of memory to allocate. |
144 | * |
145 | * The contents of the object pointed to are preserved up to the |
146 | * lesser of the new and old sizes. If @p is %NULL, krealloc() |
147 | * behaves exactly like kmalloc(). If @size is 0 and @p is not a |
148 | * %NULL pointer, the object pointed to is freed. |
149 | */ |
150 | void *krealloc(const void *p, size_t new_size, gfp_t flags) |
151 | { |
152 | void *ret; |
153 | |
154 | if (unlikely(!new_size)) { |
155 | kfree(p); |
156 | return ZERO_SIZE_PTR; |
157 | } |
158 | |
159 | ret = __krealloc(p, new_size, flags); |
160 | if (ret && p != ret) |
161 | kfree(p); |
162 | |
163 | return ret; |
164 | } |
165 | EXPORT_SYMBOL(krealloc); |
166 | |
167 | /** |
168 | * kzfree - like kfree but zero memory |
169 | * @p: object to free memory of |
170 | * |
171 | * The memory of the object @p points to is zeroed before freed. |
172 | * If @p is %NULL, kzfree() does nothing. |
173 | * |
174 | * Note: this function zeroes the whole allocated buffer which can be a good |
175 | * deal bigger than the requested buffer size passed to kmalloc(). So be |
176 | * careful when using this function in performance sensitive code. |
177 | */ |
178 | void kzfree(const void *p) |
179 | { |
180 | size_t ks; |
181 | void *mem = (void *)p; |
182 | |
183 | if (unlikely(ZERO_OR_NULL_PTR(mem))) |
184 | return; |
185 | ks = ksize(mem); |
186 | memset(mem, 0, ks); |
187 | kfree(mem); |
188 | } |
189 | EXPORT_SYMBOL(kzfree); |
190 | |
191 | /* |
192 | * strndup_user - duplicate an existing string from user space |
193 | * @s: The string to duplicate |
194 | * @n: Maximum number of bytes to copy, including the trailing NUL. |
195 | */ |
196 | char *strndup_user(const char __user *s, long n) |
197 | { |
198 | char *p; |
199 | long length; |
200 | |
201 | length = strnlen_user(s, n); |
202 | |
203 | if (!length) |
204 | return ERR_PTR(-EFAULT); |
205 | |
206 | if (length > n) |
207 | return ERR_PTR(-EINVAL); |
208 | |
209 | p = memdup_user(s, length); |
210 | |
211 | if (IS_ERR(p)) |
212 | return p; |
213 | |
214 | p[length - 1] = '\0'; |
215 | |
216 | return p; |
217 | } |
218 | EXPORT_SYMBOL(strndup_user); |
219 | |
220 | void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma, |
221 | struct vm_area_struct *prev, struct rb_node *rb_parent) |
222 | { |
223 | struct vm_area_struct *next; |
224 | |
225 | vma->vm_prev = prev; |
226 | if (prev) { |
227 | next = prev->vm_next; |
228 | prev->vm_next = vma; |
229 | } else { |
230 | mm->mmap = vma; |
231 | if (rb_parent) |
232 | next = rb_entry(rb_parent, |
233 | struct vm_area_struct, vm_rb); |
234 | else |
235 | next = NULL; |
236 | } |
237 | vma->vm_next = next; |
238 | if (next) |
239 | next->vm_prev = vma; |
240 | } |
241 | |
242 | /* Check if the vma is being used as a stack by this task */ |
243 | static int vm_is_stack_for_task(struct task_struct *t, |
244 | struct vm_area_struct *vma) |
245 | { |
246 | return (vma->vm_start <= KSTK_ESP(t) && vma->vm_end >= KSTK_ESP(t)); |
247 | } |
248 | |
249 | /* |
250 | * Check if the vma is being used as a stack. |
251 | * If is_group is non-zero, check in the entire thread group or else |
252 | * just check in the current task. Returns the pid of the task that |
253 | * the vma is stack for. |
254 | */ |
255 | pid_t vm_is_stack(struct task_struct *task, |
256 | struct vm_area_struct *vma, int in_group) |
257 | { |
258 | pid_t ret = 0; |
259 | |
260 | if (vm_is_stack_for_task(task, vma)) |
261 | return task->pid; |
262 | |
263 | if (in_group) { |
264 | struct task_struct *t; |
265 | rcu_read_lock(); |
266 | if (!pid_alive(task)) |
267 | goto done; |
268 | |
269 | t = task; |
270 | do { |
271 | if (vm_is_stack_for_task(t, vma)) { |
272 | ret = t->pid; |
273 | goto done; |
274 | } |
275 | } while_each_thread(task, t); |
276 | done: |
277 | rcu_read_unlock(); |
278 | } |
279 | |
280 | return ret; |
281 | } |
282 | |
283 | #if defined(CONFIG_MMU) && !defined(HAVE_ARCH_PICK_MMAP_LAYOUT) |
284 | void arch_pick_mmap_layout(struct mm_struct *mm) |
285 | { |
286 | mm->mmap_base = TASK_UNMAPPED_BASE; |
287 | mm->get_unmapped_area = arch_get_unmapped_area; |
288 | mm->unmap_area = arch_unmap_area; |
289 | } |
290 | #endif |
291 | |
292 | /* |
293 | * Like get_user_pages_fast() except its IRQ-safe in that it won't fall |
294 | * back to the regular GUP. |
295 | * If the architecture not support this function, simply return with no |
296 | * page pinned |
297 | */ |
298 | int __attribute__((weak)) __get_user_pages_fast(unsigned long start, |
299 | int nr_pages, int write, struct page **pages) |
300 | { |
301 | return 0; |
302 | } |
303 | EXPORT_SYMBOL_GPL(__get_user_pages_fast); |
304 | |
305 | /** |
306 | * get_user_pages_fast() - pin user pages in memory |
307 | * @start: starting user address |
308 | * @nr_pages: number of pages from start to pin |
309 | * @write: whether pages will be written to |
310 | * @pages: array that receives pointers to the pages pinned. |
311 | * Should be at least nr_pages long. |
312 | * |
313 | * Returns number of pages pinned. This may be fewer than the number |
314 | * requested. If nr_pages is 0 or negative, returns 0. If no pages |
315 | * were pinned, returns -errno. |
316 | * |
317 | * get_user_pages_fast provides equivalent functionality to get_user_pages, |
318 | * operating on current and current->mm, with force=0 and vma=NULL. However |
319 | * unlike get_user_pages, it must be called without mmap_sem held. |
320 | * |
321 | * get_user_pages_fast may take mmap_sem and page table locks, so no |
322 | * assumptions can be made about lack of locking. get_user_pages_fast is to be |
323 | * implemented in a way that is advantageous (vs get_user_pages()) when the |
324 | * user memory area is already faulted in and present in ptes. However if the |
325 | * pages have to be faulted in, it may turn out to be slightly slower so |
326 | * callers need to carefully consider what to use. On many architectures, |
327 | * get_user_pages_fast simply falls back to get_user_pages. |
328 | */ |
329 | int __attribute__((weak)) get_user_pages_fast(unsigned long start, |
330 | int nr_pages, int write, struct page **pages) |
331 | { |
332 | struct mm_struct *mm = current->mm; |
333 | int ret; |
334 | |
335 | down_read(&mm->mmap_sem); |
336 | ret = get_user_pages(current, mm, start, nr_pages, |
337 | write, 0, pages, NULL); |
338 | up_read(&mm->mmap_sem); |
339 | |
340 | return ret; |
341 | } |
342 | EXPORT_SYMBOL_GPL(get_user_pages_fast); |
343 | |
344 | /* Tracepoints definitions. */ |
345 | EXPORT_TRACEPOINT_SYMBOL(kmalloc); |
346 | EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc); |
347 | EXPORT_TRACEPOINT_SYMBOL(kmalloc_node); |
348 | EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node); |
349 | EXPORT_TRACEPOINT_SYMBOL(kfree); |
350 | EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free); |
351 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9