Makefile
1
2
3
4
5
6
7
8
9
10
KVERS = $(shell
uname
-r)
# Kernel modules
obj-m += proc.o
# Specify flags for the module compilation.
#EXTRA_CFLAGS=-g -O0
build: kernel_modules
kernel_modules:
make
-C
/lib/modules/
$(KVERS)
/build
M=$(CURDIR) modules
clean:
make
-C
/lib/modules/
$(KVERS)
/build
M=$(CURDIR) clean
proc.c
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
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/version.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <asm/uaccess.h>
static
unsigned
int
variable;
static
struct
proc_dir_entry *test_dir, *test_entry;
#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 10, 0)
static
int
test_proc_read(
char
*buf,
char
**start, off_t off,
int
count,
int
*eof,
void
*data)
{
unsigned
int
*ptr_var = data;
return
sprintf
(buf,
"test_rw = %u\n"
, *ptr_var);
}
static
int
test_proc_write(
struct
file *file,
const
char
*buffer,
unsigned
long
count,
void
*data)
{
unsigned
int
*ptr_var = data;
*ptr_var = simple_strtoul(buffer, NULL, 10);
return
count;
}
#else
static
int
test_proc_show(
struct
seq_file *seq,
void
*v)
{
unsigned
int
*ptr_var = seq->
private
;
seq_printf(seq,
"%u\n"
, *ptr_var);
return
0;
}
static
ssize_t test_proc_write(
struct
file *file,
const
char
__user *buffer,
size_t
count, loff_t *ppos)
{
struct
seq_file *seq = file->private_data;
unsigned
int
*ptr_var = seq->
private
;
int
err;
char
*kbuffer;
if
(!buffer || count > PAGE_SIZE - 1)
return
-EINVAL;
kbuffer = (
char
*)__get_free_page(GFP_KERNEL);
if
(!kbuffer)
return
-ENOMEM;
err = -EFAULT;
if
(copy_from_user(kbuffer, buffer, count))
goto
out;
kbuffer[count] =
'\0'
;
*ptr_var = simple_strtoul(kbuffer, NULL, 10);
return
count;
out:
free_page((unsigned
long
)buffer);
return
err;
}
static
int
test_proc_open(
struct
inode *inode,
struct
file *file)
{
return
single_open(file, test_proc_show, PDE_DATA(inode));
}
static
const
struct
file_operations test_proc_fops =
{
.owner = THIS_MODULE,
.open = test_proc_open,
.read = seq_read,
.write = test_proc_write,
.llseek = seq_lseek,
.release = single_release,
};
#endif
static
__init
int
test_proc_init(
void
)
{
test_dir = proc_mkdir(
"test_dir"
, NULL);
if
(test_dir) {
#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 10, 0)
test_entry = create_proc_entry(
"test_rw"
, 0666, test_dir);
if
(test_entry) {
test_entry->nlink = 1;
test_entry->data = &variable;
test_entry->read_proc = test_proc_read;
test_entry->write_proc = test_proc_write;
return
0;
}
#else
test_entry = proc_create_data(
"test_rw"
,0666, test_dir, &test_proc_fops, &variable);
if
(test_entry)
return
0;
#endif
}
return
-ENOMEM;
}
module_init(test_proc_init);
static
__exit
void
test_proc_cleanup(
void
)
{
remove_proc_entry(
"test_rw"
, test_dir);
remove_proc_entry(
"test_dir"
, NULL);
}
module_exit(test_proc_cleanup);
MODULE_AUTHOR(
"Barry Song <baohua@kernel.org>"
);
MODULE_DESCRIPTION(
"proc exmaple"
);
MODULE_LICENSE(
"GPL v2"
);
```
转载于:https://www.cnblogs.com/gaoyang3513/p/10990573.html
