Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * kernel/ksysfs.c - sysfs attributes in /sys/kernel, which | |
3 | * are not related to any other subsystem | |
4 | * | |
5 | * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org> | |
6 | * | |
7 | * This file is release under the GPLv2 | |
8 | * | |
9 | */ | |
10 | ||
1da177e4 LT |
11 | #include <linux/kobject.h> |
12 | #include <linux/string.h> | |
13 | #include <linux/sysfs.h> | |
14 | #include <linux/module.h> | |
15 | #include <linux/init.h> | |
c330dda9 | 16 | #include <linux/kexec.h> |
1da177e4 LT |
17 | |
18 | #define KERNEL_ATTR_RO(_name) \ | |
19 | static struct subsys_attribute _name##_attr = __ATTR_RO(_name) | |
20 | ||
21 | #define KERNEL_ATTR_RW(_name) \ | |
22 | static struct subsys_attribute _name##_attr = \ | |
23 | __ATTR(_name, 0644, _name##_show, _name##_store) | |
24 | ||
f125b561 | 25 | #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET) |
0f76e5ac | 26 | /* current uevent sequence number */ |
823bccfc | 27 | static ssize_t uevent_seqnum_show(struct kset *kset, char *page) |
1da177e4 | 28 | { |
312c004d | 29 | return sprintf(page, "%llu\n", (unsigned long long)uevent_seqnum); |
1da177e4 | 30 | } |
0f76e5ac KS |
31 | KERNEL_ATTR_RO(uevent_seqnum); |
32 | ||
33 | /* uevent helper program, used during early boo */ | |
823bccfc | 34 | static ssize_t uevent_helper_show(struct kset *kset, char *page) |
0f76e5ac | 35 | { |
312c004d | 36 | return sprintf(page, "%s\n", uevent_helper); |
0f76e5ac | 37 | } |
823bccfc | 38 | static ssize_t uevent_helper_store(struct kset *kset, const char *page, size_t count) |
0f76e5ac | 39 | { |
312c004d | 40 | if (count+1 > UEVENT_HELPER_PATH_LEN) |
0f76e5ac | 41 | return -ENOENT; |
312c004d KS |
42 | memcpy(uevent_helper, page, count); |
43 | uevent_helper[count] = '\0'; | |
44 | if (count && uevent_helper[count-1] == '\n') | |
45 | uevent_helper[count-1] = '\0'; | |
0f76e5ac KS |
46 | return count; |
47 | } | |
48 | KERNEL_ATTR_RW(uevent_helper); | |
1da177e4 LT |
49 | #endif |
50 | ||
c330dda9 | 51 | #ifdef CONFIG_KEXEC |
823bccfc | 52 | static ssize_t kexec_loaded_show(struct kset *kset, char *page) |
c330dda9 JM |
53 | { |
54 | return sprintf(page, "%d\n", !!kexec_image); | |
55 | } | |
56 | KERNEL_ATTR_RO(kexec_loaded); | |
57 | ||
823bccfc | 58 | static ssize_t kexec_crash_loaded_show(struct kset *kset, char *page) |
c330dda9 JM |
59 | { |
60 | return sprintf(page, "%d\n", !!kexec_crash_image); | |
61 | } | |
62 | KERNEL_ATTR_RO(kexec_crash_loaded); | |
63 | #endif /* CONFIG_KEXEC */ | |
64 | ||
da1a679c RM |
65 | /* |
66 | * Make /sys/kernel/notes give the raw contents of our kernel .notes section. | |
67 | */ | |
0b1937ac DH |
68 | extern const void __start_notes __attribute__((weak)); |
69 | extern const void __stop_notes __attribute__((weak)); | |
da1a679c RM |
70 | #define notes_size (&__stop_notes - &__start_notes) |
71 | ||
72 | static ssize_t notes_read(struct kobject *kobj, struct bin_attribute *bin_attr, | |
73 | char *buf, loff_t off, size_t count) | |
74 | { | |
75 | memcpy(buf, &__start_notes + off, count); | |
76 | return count; | |
77 | } | |
78 | ||
79 | static struct bin_attribute notes_attr = { | |
80 | .attr = { | |
81 | .name = "notes", | |
82 | .mode = S_IRUGO, | |
83 | }, | |
84 | .read = ¬es_read, | |
85 | }; | |
86 | ||
1da177e4 LT |
87 | decl_subsys(kernel, NULL, NULL); |
88 | EXPORT_SYMBOL_GPL(kernel_subsys); | |
89 | ||
90 | static struct attribute * kernel_attrs[] = { | |
f125b561 | 91 | #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET) |
0f76e5ac KS |
92 | &uevent_seqnum_attr.attr, |
93 | &uevent_helper_attr.attr, | |
c330dda9 JM |
94 | #endif |
95 | #ifdef CONFIG_KEXEC | |
96 | &kexec_loaded_attr.attr, | |
97 | &kexec_crash_loaded_attr.attr, | |
1da177e4 LT |
98 | #endif |
99 | NULL | |
100 | }; | |
101 | ||
102 | static struct attribute_group kernel_attr_group = { | |
103 | .attrs = kernel_attrs, | |
104 | }; | |
105 | ||
106 | static int __init ksysfs_init(void) | |
107 | { | |
108 | int error = subsystem_register(&kernel_subsys); | |
109 | if (!error) | |
823bccfc | 110 | error = sysfs_create_group(&kernel_subsys.kobj, |
1da177e4 LT |
111 | &kernel_attr_group); |
112 | ||
da1a679c RM |
113 | if (!error && notes_size > 0) { |
114 | notes_attr.size = notes_size; | |
115 | error = sysfs_create_bin_file(&kernel_subsys.kobj, | |
116 | ¬es_attr); | |
117 | } | |
118 | ||
1da177e4 LT |
119 | return error; |
120 | } | |
121 | ||
122 | core_initcall(ksysfs_init); |