1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
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
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
|
/*
* bin.c - binary file operations for sysfs.
*
* Copyright (c) 2003 Patrick Mochel
* Copyright (c) 2003 Matthew Wilcox
* Copyright (c) 2004 Silicon Graphics, Inc.
*/
#undef DEBUG
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/kobject.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <asm/uaccess.h>
#include "sysfs.h"
static int
fill_read(struct dentry *dentry, char *buffer, loff_t off, size_t count)
{
struct bin_attribute * attr = to_bin_attr(dentry);
struct kobject * kobj = to_kobj(dentry->d_parent);
if (!attr->read)
return -EIO;
return attr->read(kobj, buffer, off, count);
}
static ssize_t
read(struct file * file, char __user * userbuf, size_t count, loff_t * off)
{
char *buffer = file->private_data;
struct dentry *dentry = file->f_path.dentry;
int size = dentry->d_inode->i_size;
loff_t offs = *off;
int ret;
if (count > PAGE_SIZE)
count = PAGE_SIZE;
if (size) {
if (offs > size)
return 0;
if (offs + count > size)
count = size - offs;
}
ret = fill_read(dentry, buffer, offs, count);
if (ret < 0)
return ret;
count = ret;
if (copy_to_user(userbuf, buffer, count))
return -EFAULT;
pr_debug("offs = %lld, *off = %lld, count = %zd\n", offs, *off, count);
*off = offs + count;
return count;
}
static int
flush_write(struct dentry *dentry, char *buffer, loff_t offset, size_t count)
{
struct bin_attribute *attr = to_bin_attr(dentry);
struct kobject *kobj = to_kobj(dentry->d_parent);
if (!attr->write)
return -EIO;
return attr->write(kobj, buffer, offset, count);
}
static ssize_t write(struct file * file, const char __user * userbuf,
size_t count, loff_t * off)
{
char *buffer = file->private_data;
struct dentry *dentry = file->f_path.dentry;
int size = dentry->d_inode->i_size;
loff_t offs = *off;
if (count > PAGE_SIZE)
count = PAGE_SIZE;
if (size) {
if (offs > size)
return 0;
if (offs + count > size)
count = size - offs;
}
if (copy_from_user(buffer, userbuf, count))
return -EFAULT;
count = flush_write(dentry, buffer, offs, count);
if (count > 0)
*off = offs + count;
return count;
}
static int mmap(struct file *file, struct vm_area_struct *vma)
{
struct dentry *dentry = file->f_path.dentry;
struct bin_attribute *attr = to_bin_attr(dentry);
struct kobject *kobj = to_kobj(dentry->d_parent);
if (!attr->mmap)
return -EINVAL;
return attr->mmap(kobj, attr, vma);
}
static int open(struct inode * inode, struct file * file)
{
struct kobject *kobj = sysfs_get_kobject(file->f_path.dentry->d_parent);
struct bin_attribute * attr = to_bin_attr(file->f_path.dentry);
int error = -EINVAL;
if (!kobj || !attr)
goto Done;
/* Grab the module reference for this attribute if we have one */
error = -ENODEV;
if (!try_module_get(attr->attr.owner))
goto Done;
error = -EACCES;
if ((file->f_mode & FMODE_WRITE) && !(attr->write || attr->mmap))
goto Error;
if ((file->f_mode & FMODE_READ) && !(attr->read || attr->mmap))
goto Error;
error = -ENOMEM;
file->private_data = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (!file->private_data)
goto Error;
error = 0;
goto Done;
Error:
module_put(attr->attr.owner);
Done:
if (error && kobj)
kobject_put(kobj);
return error;
}
static int release(struct inode * inode, struct file * file)
{
struct kobject * kobj = to_kobj(file->f_path.dentry->d_parent);
struct bin_attribute * attr = to_bin_attr(file->f_path.dentry);
u8 * buffer = file->private_data;
if (kobj)
kobject_put(kobj);
module_put(attr->attr.owner);
kfree(buffer);
return 0;
}
const struct file_operations bin_fops = {
.read = read,
.write = write,
.mmap = mmap,
.llseek = generic_file_llseek,
.open = open,
.release = release,
};
/**
* sysfs_create_bin_file - create binary file for object.
* @kobj: object.
* @attr: attribute descriptor.
*/
int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr)
{
BUG_ON(!kobj || !kobj->dentry || !attr);
return sysfs_add_file(kobj->dentry, &attr->attr, SYSFS_KOBJ_BIN_ATTR);
}
/**
* sysfs_remove_bin_file - remove binary file for object.
* @kobj: object.
* @attr: attribute descriptor.
*/
void sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr)
{
if (sysfs_hash_and_remove(kobj->dentry, attr->attr.name) < 0) {
printk(KERN_ERR "%s: "
"bad dentry or inode or no such file: \"%s\"\n",
__FUNCTION__, attr->attr.name);
dump_stack();
}
}
EXPORT_SYMBOL_GPL(sysfs_create_bin_file);
EXPORT_SYMBOL_GPL(sysfs_remove_bin_file);
|
