Eric Lee / smarc-fsl-linux-kernel

Blame view

kernel/regset.c 1.85 KB
edit raw normal view history
b4e9c9549   Al Viro   introduction of r... 
1
2
3
4
5
6
7
8
9
10
11
12
 
  // SPDX-License-Identifier: GPL-2.0-only
  #include <linux/export.h>
  #include <linux/slab.h>
  #include <linux/regset.h>
  
  static int __regset_get(struct task_struct *target,
  			const struct user_regset *regset,
  			unsigned int size,
  			void **data)
  {
  	void *p = *data, *to_free = NULL;
  	int res;
1e6986c9d   Al Viro   regset: kill ->get() 
13
 
  	if (!regset->regset_get)
b4e9c9549   Al Viro   introduction of r... 
14
15
16
17
18
19
20
21
 
  		return -EOPNOTSUPP;
  	if (size > regset->n * regset->size)
  		size = regset->n * regset->size;
  	if (!p) {
  		to_free = p = kzalloc(size, GFP_KERNEL);
  		if (!p)
  			return -ENOMEM;
  	}
1e6986c9d   Al Viro   regset: kill ->get() 
22
23
24
 
  	res = regset->regset_get(target, regset,
  			   (struct membuf){.p = p, .left = size});
  	if (res < 0) {
b4e9c9549   Al Viro   introduction of r... 
25
26
27
28
 
  		kfree(to_free);
  		return res;
  	}
  	*data = p;
1e6986c9d   Al Viro   regset: kill ->get() 
29
 
  	return size - res;
b4e9c9549   Al Viro   introduction of r... 
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
 
  }
  
  int regset_get(struct task_struct *target,
  	       const struct user_regset *regset,
  	       unsigned int size,
  	       void *data)
  {
  	return __regset_get(target, regset, size, &data);
  }
  EXPORT_SYMBOL(regset_get);
  
  int regset_get_alloc(struct task_struct *target,
  		     const struct user_regset *regset,
  		     unsigned int size,
  		     void **data)
  {
  	*data = NULL;
  	return __regset_get(target, regset, size, data);
  }
  EXPORT_SYMBOL(regset_get_alloc);
dc12d7968   Al Viro   copy_regset_to_us... 
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
 
  
  /**
   * copy_regset_to_user - fetch a thread's user_regset data into user memory
   * @target:	thread to be examined
   * @view:	&struct user_regset_view describing user thread machine state
   * @setno:	index in @view->regsets
   * @offset:	offset into the regset data, in bytes
   * @size:	amount of data to copy, in bytes
   * @data:	user-mode pointer to copy into
   */
  int copy_regset_to_user(struct task_struct *target,
  			const struct user_regset_view *view,
  			unsigned int setno,
  			unsigned int offset, unsigned int size,
  			void __user *data)
  {
  	const struct user_regset *regset = &view->regsets[setno];
  	void *buf;
  	int ret;
  
  	ret = regset_get_alloc(target, regset, size, &buf);
  	if (ret > 0)
  		ret = copy_to_user(data, buf, ret) ? -EFAULT : 0;
  	kfree(buf);
  	return ret;
  }