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1#include <linux/mm.h>
2#include <linux/slab.h>
3#include <linux/string.h>
4#include <linux/compiler.h>
5#include <linux/export.h>
6#include <linux/err.h>
7#include <linux/sched.h>
8#include <linux/security.h>
9#include <linux/swap.h>
10#include <linux/swapops.h>
11#include <linux/mman.h>
12#include <linux/hugetlb.h>
13#include <linux/vmalloc.h>
14
15#include <asm/uaccess.h>
16
17#include "internal.h"
18
19#define CREATE_TRACE_POINTS
20#include <trace/events/kmem.h>
21
22/**
23 * kstrdup - allocate space for and copy an existing string
24 * @s: the string to duplicate
25 * @gfp: the GFP mask used in the kmalloc() call when allocating memory
26 */
27char *kstrdup(const char *s, gfp_t gfp)
28{
29 size_t len;
30 char *buf;
31
32 if (!s)
33 return NULL;
34
35 len = strlen(s) + 1;
36 buf = kmalloc_track_caller(len, gfp);
37 if (buf)
38 memcpy(buf, s, len);
39 return buf;
40}
41EXPORT_SYMBOL(kstrdup);
42
43/**
44 * kstrndup - allocate space for and copy an existing string
45 * @s: the string to duplicate
46 * @max: read at most @max chars from @s
47 * @gfp: the GFP mask used in the kmalloc() call when allocating memory
48 */
49char *kstrndup(const char *s, size_t max, gfp_t gfp)
50{
51 size_t len;
52 char *buf;
53
54 if (!s)
55 return NULL;
56
57 len = strnlen(s, max);
58 buf = kmalloc_track_caller(len+1, gfp);
59 if (buf) {
60 memcpy(buf, s, len);
61 buf[len] = '\0';
62 }
63 return buf;
64}
65EXPORT_SYMBOL(kstrndup);
66
67/**
68 * kmemdup - duplicate region of memory
69 *
70 * @src: memory region to duplicate
71 * @len: memory region length
72 * @gfp: GFP mask to use
73 */
74void *kmemdup(const void *src, size_t len, gfp_t gfp)
75{
76 void *p;
77
78 p = kmalloc_track_caller(len, gfp);
79 if (p)
80 memcpy(p, src, len);
81 return p;
82}
83EXPORT_SYMBOL(kmemdup);
84
85/**
86 * memdup_user - duplicate memory region from user space
87 *
88 * @src: source address in user space
89 * @len: number of bytes to copy
90 *
91 * Returns an ERR_PTR() on failure.
92 */
93void *memdup_user(const void __user *src, size_t len)
94{
95 void *p;
96
97 /*
98 * Always use GFP_KERNEL, since copy_from_user() can sleep and
99 * cause pagefault, which makes it pointless to use GFP_NOFS
100 * or GFP_ATOMIC.
101 */
102 p = kmalloc_track_caller(len, GFP_KERNEL);
103 if (!p)
104 return ERR_PTR(-ENOMEM);
105
106 if (copy_from_user(p, src, len)) {
107 kfree(p);
108 return ERR_PTR(-EFAULT);
109 }
110
111 return p;
112}
113EXPORT_SYMBOL(memdup_user);
114
115static __always_inline void *__do_krealloc(const void *p, size_t new_size,
116 gfp_t flags)
117{
118 void *ret;
119 size_t ks = 0;
120
121 if (p)
122 ks = ksize(p);
123
124 if (ks >= new_size)
125 return (void *)p;
126
127 ret = kmalloc_track_caller(new_size, flags);
128 if (ret && p)
129 memcpy(ret, p, ks);
130
131 return ret;
132}
133
134/**
135 * __krealloc - like krealloc() but don't free @p.
136 * @p: object to reallocate memory for.
137 * @new_size: how many bytes of memory are required.
138 * @flags: the type of memory to allocate.
139 *
140 * This function is like krealloc() except it never frees the originally
141 * allocated buffer. Use this if you don't want to free the buffer immediately
142 * like, for example, with RCU.
143 */
144void *__krealloc(const void *p, size_t new_size, gfp_t flags)
145{
146 if (unlikely(!new_size))
147 return ZERO_SIZE_PTR;
148
149 return __do_krealloc(p, new_size, flags);
150
151}
152EXPORT_SYMBOL(__krealloc);
153
154/**
155 * krealloc - reallocate memory. The contents will remain unchanged.
156 * @p: object to reallocate memory for.
157 * @new_size: how many bytes of memory are required.
158 * @flags: the type of memory to allocate.
159 *
160 * The contents of the object pointed to are preserved up to the
161 * lesser of the new and old sizes. If @p is %NULL, krealloc()
162 * behaves exactly like kmalloc(). If @new_size is 0 and @p is not a
163 * %NULL pointer, the object pointed to is freed.
164 */
165void *krealloc(const void *p, size_t new_size, gfp_t flags)
166{
167 void *ret;
168
169 if (unlikely(!new_size)) {
170 kfree(p);
171 return ZERO_SIZE_PTR;
172 }
173
174 ret = __do_krealloc(p, new_size, flags);
175 if (ret && p != ret)
176 kfree(p);
177
178 return ret;
179}
180EXPORT_SYMBOL(krealloc);
181
182/**
183 * kzfree - like kfree but zero memory
184 * @p: object to free memory of
185 *
186 * The memory of the object @p points to is zeroed before freed.
187 * If @p is %NULL, kzfree() does nothing.
188 *
189 * Note: this function zeroes the whole allocated buffer which can be a good
190 * deal bigger than the requested buffer size passed to kmalloc(). So be
191 * careful when using this function in performance sensitive code.
192 */
193void kzfree(const void *p)
194{
195 size_t ks;
196 void *mem = (void *)p;
197
198 if (unlikely(ZERO_OR_NULL_PTR(mem)))
199 return;
200 ks = ksize(mem);
201 memset(mem, 0, ks);
202 kfree(mem);
203}
204EXPORT_SYMBOL(kzfree);
205
206/*
207 * strndup_user - duplicate an existing string from user space
208 * @s: The string to duplicate
209 * @n: Maximum number of bytes to copy, including the trailing NUL.
210 */
211char *strndup_user(const char __user *s, long n)
212{
213 char *p;
214 long length;
215
216 length = strnlen_user(s, n);
217
218 if (!length)
219 return ERR_PTR(-EFAULT);
220
221 if (length > n)
222 return ERR_PTR(-EINVAL);
223
224 p = memdup_user(s, length);
225
226 if (IS_ERR(p))
227 return p;
228
229 p[length - 1] = '\0';
230
231 return p;
232}
233EXPORT_SYMBOL(strndup_user);
234
235void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
236 struct vm_area_struct *prev, struct rb_node *rb_parent)
237{
238 struct vm_area_struct *next;
239
240 vma->vm_prev = prev;
241 if (prev) {
242 next = prev->vm_next;
243 prev->vm_next = vma;
244 } else {
245 mm->mmap = vma;
246 if (rb_parent)
247 next = rb_entry(rb_parent,
248 struct vm_area_struct, vm_rb);
249 else
250 next = NULL;
251 }
252 vma->vm_next = next;
253 if (next)
254 next->vm_prev = vma;
255}
256
257/* Check if the vma is being used as a stack by this task */
258static int vm_is_stack_for_task(struct task_struct *t,
259 struct vm_area_struct *vma)
260{
261 return (vma->vm_start <= KSTK_ESP(t) && vma->vm_end >= KSTK_ESP(t));
262}
263
264/*
265 * Check if the vma is being used as a stack.
266 * If is_group is non-zero, check in the entire thread group or else
267 * just check in the current task. Returns the pid of the task that
268 * the vma is stack for.
269 */
270pid_t vm_is_stack(struct task_struct *task,
271 struct vm_area_struct *vma, int in_group)
272{
273 pid_t ret = 0;
274
275 if (vm_is_stack_for_task(task, vma))
276 return task->pid;
277
278 if (in_group) {
279 struct task_struct *t;
280 rcu_read_lock();
281 if (!pid_alive(task))
282 goto done;
283
284 t = task;
285 do {
286 if (vm_is_stack_for_task(t, vma)) {
287 ret = t->pid;
288 goto done;
289 }
290 } while_each_thread(task, t);
291done:
292 rcu_read_unlock();
293 }
294
295 return ret;
296}
297
298#if defined(CONFIG_MMU) && !defined(HAVE_ARCH_PICK_MMAP_LAYOUT)
299void arch_pick_mmap_layout(struct mm_struct *mm)
300{
301 mm->mmap_base = TASK_UNMAPPED_BASE;
302 mm->get_unmapped_area = arch_get_unmapped_area;
303}
304#endif
305
306/*
307 * Like get_user_pages_fast() except its IRQ-safe in that it won't fall
308 * back to the regular GUP.
309 * If the architecture not support this function, simply return with no
310 * page pinned
311 */
312int __weak __get_user_pages_fast(unsigned long start,
313 int nr_pages, int write, struct page **pages)
314{
315 return 0;
316}
317EXPORT_SYMBOL_GPL(__get_user_pages_fast);
318
319/**
320 * get_user_pages_fast() - pin user pages in memory
321 * @start: starting user address
322 * @nr_pages: number of pages from start to pin
323 * @write: whether pages will be written to
324 * @pages: array that receives pointers to the pages pinned.
325 * Should be at least nr_pages long.
326 *
327 * Returns number of pages pinned. This may be fewer than the number
328 * requested. If nr_pages is 0 or negative, returns 0. If no pages
329 * were pinned, returns -errno.
330 *
331 * get_user_pages_fast provides equivalent functionality to get_user_pages,
332 * operating on current and current->mm, with force=0 and vma=NULL. However
333 * unlike get_user_pages, it must be called without mmap_sem held.
334 *
335 * get_user_pages_fast may take mmap_sem and page table locks, so no
336 * assumptions can be made about lack of locking. get_user_pages_fast is to be
337 * implemented in a way that is advantageous (vs get_user_pages()) when the
338 * user memory area is already faulted in and present in ptes. However if the
339 * pages have to be faulted in, it may turn out to be slightly slower so
340 * callers need to carefully consider what to use. On many architectures,
341 * get_user_pages_fast simply falls back to get_user_pages.
342 */
343int __weak get_user_pages_fast(unsigned long start,
344 int nr_pages, int write, struct page **pages)
345{
346 struct mm_struct *mm = current->mm;
347 int ret;
348
349 down_read(&mm->mmap_sem);
350 ret = get_user_pages(current, mm, start, nr_pages,
351 write, 0, pages, NULL);
352 up_read(&mm->mmap_sem);
353
354 return ret;
355}
356EXPORT_SYMBOL_GPL(get_user_pages_fast);
357
358unsigned long vm_mmap_pgoff(struct file *file, unsigned long addr,
359 unsigned long len, unsigned long prot,
360 unsigned long flag, unsigned long pgoff)
361{
362 unsigned long ret;
363 struct mm_struct *mm = current->mm;
364 unsigned long populate;
365
366 ret = security_mmap_file(file, prot, flag);
367 if (!ret) {
368 down_write(&mm->mmap_sem);
369 ret = do_mmap_pgoff(file, addr, len, prot, flag, pgoff,
370 &populate);
371 up_write(&mm->mmap_sem);
372 if (populate)
373 mm_populate(ret, populate);
374 }
375 return ret;
376}
377
378unsigned long vm_mmap(struct file *file, unsigned long addr,
379 unsigned long len, unsigned long prot,
380 unsigned long flag, unsigned long offset)
381{
382 if (unlikely(offset + PAGE_ALIGN(len) < offset))
383 return -EINVAL;
384 if (unlikely(offset & ~PAGE_MASK))
385 return -EINVAL;
386
387 return vm_mmap_pgoff(file, addr, len, prot, flag, offset >> PAGE_SHIFT);
388}
389EXPORT_SYMBOL(vm_mmap);
390
391void kvfree(const void *addr)
392{
393 if (is_vmalloc_addr(addr))
394 vfree(addr);
395 else
396 kfree(addr);
397}
398EXPORT_SYMBOL(kvfree);
399
400struct address_space *page_mapping(struct page *page)
401{
402 struct address_space *mapping = page->mapping;
403
404 /* This happens if someone calls flush_dcache_page on slab page */
405 if (unlikely(PageSlab(page)))
406 return NULL;
407
408 if (unlikely(PageSwapCache(page))) {
409 swp_entry_t entry;
410
411 entry.val = page_private(page);
412 mapping = swap_address_space(entry);
413 } else if ((unsigned long)mapping & PAGE_MAPPING_ANON)
414 mapping = NULL;
415 return mapping;
416}
417
418int overcommit_ratio_handler(struct ctl_table *table, int write,
419 void __user *buffer, size_t *lenp,
420 loff_t *ppos)
421{
422 int ret;
423
424 ret = proc_dointvec(table, write, buffer, lenp, ppos);
425 if (ret == 0 && write)
426 sysctl_overcommit_kbytes = 0;
427 return ret;
428}
429
430int overcommit_kbytes_handler(struct ctl_table *table, int write,
431 void __user *buffer, size_t *lenp,
432 loff_t *ppos)
433{
434 int ret;
435
436 ret = proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
437 if (ret == 0 && write)
438 sysctl_overcommit_ratio = 0;
439 return ret;
440}
441
442/*
443 * Committed memory limit enforced when OVERCOMMIT_NEVER policy is used
444 */
445unsigned long vm_commit_limit(void)
446{
447 unsigned long allowed;
448
449 if (sysctl_overcommit_kbytes)
450 allowed = sysctl_overcommit_kbytes >> (PAGE_SHIFT - 10);
451 else
452 allowed = ((totalram_pages - hugetlb_total_pages())
453 * sysctl_overcommit_ratio / 100);
454 allowed += total_swap_pages;
455
456 return allowed;
457}
458
459/**
460 * get_cmdline() - copy the cmdline value to a buffer.
461 * @task: the task whose cmdline value to copy.
462 * @buffer: the buffer to copy to.
463 * @buflen: the length of the buffer. Larger cmdline values are truncated
464 * to this length.
465 * Returns the size of the cmdline field copied. Note that the copy does
466 * not guarantee an ending NULL byte.
467 */
468int get_cmdline(struct task_struct *task, char *buffer, int buflen)
469{
470 int res = 0;
471 unsigned int len;
472 struct mm_struct *mm = get_task_mm(task);
473 if (!mm)
474 goto out;
475 if (!mm->arg_end)
476 goto out_mm; /* Shh! No looking before we're done */
477
478 len = mm->arg_end - mm->arg_start;
479
480 if (len > buflen)
481 len = buflen;
482
483 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
484
485 /*
486 * If the nul at the end of args has been overwritten, then
487 * assume application is using setproctitle(3).
488 */
489 if (res > 0 && buffer[res-1] != '\0' && len < buflen) {
490 len = strnlen(buffer, res);
491 if (len < res) {
492 res = len;
493 } else {
494 len = mm->env_end - mm->env_start;
495 if (len > buflen - res)
496 len = buflen - res;
497 res += access_process_vm(task, mm->env_start,
498 buffer+res, len, 0);
499 res = strnlen(buffer, res);
500 }
501 }
502out_mm:
503 mmput(mm);
504out:
505 return res;
506}
507
508/* Tracepoints definitions. */
509EXPORT_TRACEPOINT_SYMBOL(kmalloc);
510EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc);
511EXPORT_TRACEPOINT_SYMBOL(kmalloc_node);
512EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node);
513EXPORT_TRACEPOINT_SYMBOL(kfree);
514EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free);
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 <linux/security.h>
8#include <asm/uaccess.h>
9
10#include "internal.h"
11
12#define CREATE_TRACE_POINTS
13#include <trace/events/kmem.h>
14
15/**
16 * kstrdup - allocate space for and copy an existing string
17 * @s: the string to duplicate
18 * @gfp: the GFP mask used in the kmalloc() call when allocating memory
19 */
20char *kstrdup(const char *s, gfp_t gfp)
21{
22 size_t len;
23 char *buf;
24
25 if (!s)
26 return NULL;
27
28 len = strlen(s) + 1;
29 buf = kmalloc_track_caller(len, gfp);
30 if (buf)
31 memcpy(buf, s, len);
32 return buf;
33}
34EXPORT_SYMBOL(kstrdup);
35
36/**
37 * kstrndup - allocate space for and copy an existing string
38 * @s: the string to duplicate
39 * @max: read at most @max chars from @s
40 * @gfp: the GFP mask used in the kmalloc() call when allocating memory
41 */
42char *kstrndup(const char *s, size_t max, gfp_t gfp)
43{
44 size_t len;
45 char *buf;
46
47 if (!s)
48 return NULL;
49
50 len = strnlen(s, max);
51 buf = kmalloc_track_caller(len+1, gfp);
52 if (buf) {
53 memcpy(buf, s, len);
54 buf[len] = '\0';
55 }
56 return buf;
57}
58EXPORT_SYMBOL(kstrndup);
59
60/**
61 * kmemdup - duplicate region of memory
62 *
63 * @src: memory region to duplicate
64 * @len: memory region length
65 * @gfp: GFP mask to use
66 */
67void *kmemdup(const void *src, size_t len, gfp_t gfp)
68{
69 void *p;
70
71 p = kmalloc_track_caller(len, gfp);
72 if (p)
73 memcpy(p, src, len);
74 return p;
75}
76EXPORT_SYMBOL(kmemdup);
77
78/**
79 * memdup_user - duplicate memory region from user space
80 *
81 * @src: source address in user space
82 * @len: number of bytes to copy
83 *
84 * Returns an ERR_PTR() on failure.
85 */
86void *memdup_user(const void __user *src, size_t len)
87{
88 void *p;
89
90 /*
91 * Always use GFP_KERNEL, since copy_from_user() can sleep and
92 * cause pagefault, which makes it pointless to use GFP_NOFS
93 * or GFP_ATOMIC.
94 */
95 p = kmalloc_track_caller(len, GFP_KERNEL);
96 if (!p)
97 return ERR_PTR(-ENOMEM);
98
99 if (copy_from_user(p, src, len)) {
100 kfree(p);
101 return ERR_PTR(-EFAULT);
102 }
103
104 return p;
105}
106EXPORT_SYMBOL(memdup_user);
107
108/**
109 * __krealloc - like krealloc() but don't free @p.
110 * @p: object to reallocate memory for.
111 * @new_size: how many bytes of memory are required.
112 * @flags: the type of memory to allocate.
113 *
114 * This function is like krealloc() except it never frees the originally
115 * allocated buffer. Use this if you don't want to free the buffer immediately
116 * like, for example, with RCU.
117 */
118void *__krealloc(const void *p, size_t new_size, gfp_t flags)
119{
120 void *ret;
121 size_t ks = 0;
122
123 if (unlikely(!new_size))
124 return ZERO_SIZE_PTR;
125
126 if (p)
127 ks = ksize(p);
128
129 if (ks >= new_size)
130 return (void *)p;
131
132 ret = kmalloc_track_caller(new_size, flags);
133 if (ret && p)
134 memcpy(ret, p, ks);
135
136 return ret;
137}
138EXPORT_SYMBOL(__krealloc);
139
140/**
141 * krealloc - reallocate memory. The contents will remain unchanged.
142 * @p: object to reallocate memory for.
143 * @new_size: how many bytes of memory are required.
144 * @flags: the type of memory to allocate.
145 *
146 * The contents of the object pointed to are preserved up to the
147 * lesser of the new and old sizes. If @p is %NULL, krealloc()
148 * behaves exactly like kmalloc(). If @size is 0 and @p is not a
149 * %NULL pointer, the object pointed to is freed.
150 */
151void *krealloc(const void *p, size_t new_size, gfp_t flags)
152{
153 void *ret;
154
155 if (unlikely(!new_size)) {
156 kfree(p);
157 return ZERO_SIZE_PTR;
158 }
159
160 ret = __krealloc(p, new_size, flags);
161 if (ret && p != ret)
162 kfree(p);
163
164 return ret;
165}
166EXPORT_SYMBOL(krealloc);
167
168/**
169 * kzfree - like kfree but zero memory
170 * @p: object to free memory of
171 *
172 * The memory of the object @p points to is zeroed before freed.
173 * If @p is %NULL, kzfree() does nothing.
174 *
175 * Note: this function zeroes the whole allocated buffer which can be a good
176 * deal bigger than the requested buffer size passed to kmalloc(). So be
177 * careful when using this function in performance sensitive code.
178 */
179void kzfree(const void *p)
180{
181 size_t ks;
182 void *mem = (void *)p;
183
184 if (unlikely(ZERO_OR_NULL_PTR(mem)))
185 return;
186 ks = ksize(mem);
187 memset(mem, 0, ks);
188 kfree(mem);
189}
190EXPORT_SYMBOL(kzfree);
191
192/*
193 * strndup_user - duplicate an existing string from user space
194 * @s: The string to duplicate
195 * @n: Maximum number of bytes to copy, including the trailing NUL.
196 */
197char *strndup_user(const char __user *s, long n)
198{
199 char *p;
200 long length;
201
202 length = strnlen_user(s, n);
203
204 if (!length)
205 return ERR_PTR(-EFAULT);
206
207 if (length > n)
208 return ERR_PTR(-EINVAL);
209
210 p = memdup_user(s, length);
211
212 if (IS_ERR(p))
213 return p;
214
215 p[length - 1] = '\0';
216
217 return p;
218}
219EXPORT_SYMBOL(strndup_user);
220
221void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
222 struct vm_area_struct *prev, struct rb_node *rb_parent)
223{
224 struct vm_area_struct *next;
225
226 vma->vm_prev = prev;
227 if (prev) {
228 next = prev->vm_next;
229 prev->vm_next = vma;
230 } else {
231 mm->mmap = vma;
232 if (rb_parent)
233 next = rb_entry(rb_parent,
234 struct vm_area_struct, vm_rb);
235 else
236 next = NULL;
237 }
238 vma->vm_next = next;
239 if (next)
240 next->vm_prev = vma;
241}
242
243/* Check if the vma is being used as a stack by this task */
244static int vm_is_stack_for_task(struct task_struct *t,
245 struct vm_area_struct *vma)
246{
247 return (vma->vm_start <= KSTK_ESP(t) && vma->vm_end >= KSTK_ESP(t));
248}
249
250/*
251 * Check if the vma is being used as a stack.
252 * If is_group is non-zero, check in the entire thread group or else
253 * just check in the current task. Returns the pid of the task that
254 * the vma is stack for.
255 */
256pid_t vm_is_stack(struct task_struct *task,
257 struct vm_area_struct *vma, int in_group)
258{
259 pid_t ret = 0;
260
261 if (vm_is_stack_for_task(task, vma))
262 return task->pid;
263
264 if (in_group) {
265 struct task_struct *t;
266 rcu_read_lock();
267 if (!pid_alive(task))
268 goto done;
269
270 t = task;
271 do {
272 if (vm_is_stack_for_task(t, vma)) {
273 ret = t->pid;
274 goto done;
275 }
276 } while_each_thread(task, t);
277done:
278 rcu_read_unlock();
279 }
280
281 return ret;
282}
283
284#if defined(CONFIG_MMU) && !defined(HAVE_ARCH_PICK_MMAP_LAYOUT)
285void arch_pick_mmap_layout(struct mm_struct *mm)
286{
287 mm->mmap_base = TASK_UNMAPPED_BASE;
288 mm->get_unmapped_area = arch_get_unmapped_area;
289 mm->unmap_area = arch_unmap_area;
290}
291#endif
292
293/*
294 * Like get_user_pages_fast() except its IRQ-safe in that it won't fall
295 * back to the regular GUP.
296 * If the architecture not support this function, simply return with no
297 * page pinned
298 */
299int __attribute__((weak)) __get_user_pages_fast(unsigned long start,
300 int nr_pages, int write, struct page **pages)
301{
302 return 0;
303}
304EXPORT_SYMBOL_GPL(__get_user_pages_fast);
305
306/**
307 * get_user_pages_fast() - pin user pages in memory
308 * @start: starting user address
309 * @nr_pages: number of pages from start to pin
310 * @write: whether pages will be written to
311 * @pages: array that receives pointers to the pages pinned.
312 * Should be at least nr_pages long.
313 *
314 * Returns number of pages pinned. This may be fewer than the number
315 * requested. If nr_pages is 0 or negative, returns 0. If no pages
316 * were pinned, returns -errno.
317 *
318 * get_user_pages_fast provides equivalent functionality to get_user_pages,
319 * operating on current and current->mm, with force=0 and vma=NULL. However
320 * unlike get_user_pages, it must be called without mmap_sem held.
321 *
322 * get_user_pages_fast may take mmap_sem and page table locks, so no
323 * assumptions can be made about lack of locking. get_user_pages_fast is to be
324 * implemented in a way that is advantageous (vs get_user_pages()) when the
325 * user memory area is already faulted in and present in ptes. However if the
326 * pages have to be faulted in, it may turn out to be slightly slower so
327 * callers need to carefully consider what to use. On many architectures,
328 * get_user_pages_fast simply falls back to get_user_pages.
329 */
330int __attribute__((weak)) get_user_pages_fast(unsigned long start,
331 int nr_pages, int write, struct page **pages)
332{
333 struct mm_struct *mm = current->mm;
334 int ret;
335
336 down_read(&mm->mmap_sem);
337 ret = get_user_pages(current, mm, start, nr_pages,
338 write, 0, pages, NULL);
339 up_read(&mm->mmap_sem);
340
341 return ret;
342}
343EXPORT_SYMBOL_GPL(get_user_pages_fast);
344
345unsigned long vm_mmap_pgoff(struct file *file, unsigned long addr,
346 unsigned long len, unsigned long prot,
347 unsigned long flag, unsigned long pgoff)
348{
349 unsigned long ret;
350 struct mm_struct *mm = current->mm;
351
352 ret = security_mmap_file(file, prot, flag);
353 if (!ret) {
354 down_write(&mm->mmap_sem);
355 ret = do_mmap_pgoff(file, addr, len, prot, flag, pgoff);
356 up_write(&mm->mmap_sem);
357 }
358 return ret;
359}
360
361unsigned long vm_mmap(struct file *file, unsigned long addr,
362 unsigned long len, unsigned long prot,
363 unsigned long flag, unsigned long offset)
364{
365 if (unlikely(offset + PAGE_ALIGN(len) < offset))
366 return -EINVAL;
367 if (unlikely(offset & ~PAGE_MASK))
368 return -EINVAL;
369
370 return vm_mmap_pgoff(file, addr, len, prot, flag, offset >> PAGE_SHIFT);
371}
372EXPORT_SYMBOL(vm_mmap);
373
374/* Tracepoints definitions. */
375EXPORT_TRACEPOINT_SYMBOL(kmalloc);
376EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc);
377EXPORT_TRACEPOINT_SYMBOL(kmalloc_node);
378EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node);
379EXPORT_TRACEPOINT_SYMBOL(kfree);
380EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free);