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
|
/*
* kernel/ksysfs.c - sysfs attributes in /sys/kernel, which
* are not related to any other subsystem
*
* Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
*
* This file is release under the GPLv2
*
*/
#include <linux/config.h>
#include <linux/kobject.h>
#include <linux/string.h>
#include <linux/sysfs.h>
#include <linux/module.h>
#include <linux/init.h>
#define KERNEL_ATTR_RO(_name) \
static struct subsys_attribute _name##_attr = __ATTR_RO(_name)
#define KERNEL_ATTR_RW(_name) \
static struct subsys_attribute _name##_attr = \
__ATTR(_name, 0644, _name##_show, _name##_store)
#ifdef CONFIG_HOTPLUG
/* current uevent sequence number */
static ssize_t uevent_seqnum_show(struct subsystem *subsys, char *page)
{
return sprintf(page, "%llu\n", (unsigned long long)uevent_seqnum);
}
KERNEL_ATTR_RO(uevent_seqnum);
/* uevent helper program, used during early boo */
static ssize_t uevent_helper_show(struct subsystem *subsys, char *page)
{
return sprintf(page, "%s\n", uevent_helper);
}
static ssize_t uevent_helper_store(struct subsystem *subsys, const char *page, size_t count)
{
if (count+1 > UEVENT_HELPER_PATH_LEN)
return -ENOENT;
memcpy(uevent_helper, page, count);
uevent_helper[count] = '\0';
if (count && uevent_helper[count-1] == '\n')
uevent_helper[count-1] = '\0';
return count;
}
KERNEL_ATTR_RW(uevent_helper);
#endif
#ifdef CONFIG_KEXEC
#include <asm/kexec.h>
static ssize_t crash_notes_show(struct subsystem *subsys, char *page)
{
return sprintf(page, "%p\n", (void *)crash_notes);
}
KERNEL_ATTR_RO(crash_notes);
#endif
decl_subsys(kernel, NULL, NULL);
EXPORT_SYMBOL_GPL(kernel_subsys);
static struct attribute * kernel_attrs[] = {
#ifdef CONFIG_HOTPLUG
&uevent_seqnum_attr.attr,
&uevent_helper_attr.attr,
#endif
#ifdef CONFIG_KEXEC
&crash_notes_attr.attr,
#endif
NULL
};
static struct attribute_group kernel_attr_group = {
.attrs = kernel_attrs,
};
static int __init ksysfs_init(void)
{
int error = subsystem_register(&kernel_subsys);
if (!error)
error = sysfs_create_group(&kernel_subsys.kset.kobj,
&kernel_attr_group);
return error;
}
core_initcall(ksysfs_init);
|
