Commit | Line | Data |
---|---|---|
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> | |
9984de1a | 14 | #include <linux/export.h> |
1da177e4 | 15 | #include <linux/init.h> |
c330dda9 | 16 | #include <linux/kexec.h> |
22b8ce94 | 17 | #include <linux/profile.h> |
1596425f | 18 | #include <linux/stat.h> |
5cb350ba | 19 | #include <linux/sched.h> |
088ab0b4 | 20 | #include <linux/capability.h> |
52f5684c | 21 | #include <linux/compiler.h> |
1da177e4 | 22 | |
7a754743 PG |
23 | #include <linux/rcupdate.h> /* rcu_expedited */ |
24 | ||
1da177e4 | 25 | #define KERNEL_ATTR_RO(_name) \ |
386f275f | 26 | static struct kobj_attribute _name##_attr = __ATTR_RO(_name) |
1da177e4 LT |
27 | |
28 | #define KERNEL_ATTR_RW(_name) \ | |
386f275f | 29 | static struct kobj_attribute _name##_attr = \ |
1da177e4 LT |
30 | __ATTR(_name, 0644, _name##_show, _name##_store) |
31 | ||
0f76e5ac | 32 | /* current uevent sequence number */ |
386f275f KS |
33 | static ssize_t uevent_seqnum_show(struct kobject *kobj, |
34 | struct kobj_attribute *attr, char *buf) | |
1da177e4 | 35 | { |
386f275f | 36 | return sprintf(buf, "%llu\n", (unsigned long long)uevent_seqnum); |
1da177e4 | 37 | } |
0f76e5ac KS |
38 | KERNEL_ATTR_RO(uevent_seqnum); |
39 | ||
af665852 | 40 | /* uevent helper program, used during early boot */ |
386f275f KS |
41 | static ssize_t uevent_helper_show(struct kobject *kobj, |
42 | struct kobj_attribute *attr, char *buf) | |
0f76e5ac | 43 | { |
386f275f | 44 | return sprintf(buf, "%s\n", uevent_helper); |
0f76e5ac | 45 | } |
386f275f KS |
46 | static ssize_t uevent_helper_store(struct kobject *kobj, |
47 | struct kobj_attribute *attr, | |
48 | const char *buf, size_t count) | |
0f76e5ac | 49 | { |
312c004d | 50 | if (count+1 > UEVENT_HELPER_PATH_LEN) |
0f76e5ac | 51 | return -ENOENT; |
386f275f | 52 | memcpy(uevent_helper, buf, count); |
312c004d KS |
53 | uevent_helper[count] = '\0'; |
54 | if (count && uevent_helper[count-1] == '\n') | |
55 | uevent_helper[count-1] = '\0'; | |
0f76e5ac KS |
56 | return count; |
57 | } | |
58 | KERNEL_ATTR_RW(uevent_helper); | |
e3a1a5ec | 59 | |
1da177e4 | 60 | |
22b8ce94 DH |
61 | #ifdef CONFIG_PROFILING |
62 | static ssize_t profiling_show(struct kobject *kobj, | |
63 | struct kobj_attribute *attr, char *buf) | |
64 | { | |
65 | return sprintf(buf, "%d\n", prof_on); | |
66 | } | |
67 | static ssize_t profiling_store(struct kobject *kobj, | |
68 | struct kobj_attribute *attr, | |
69 | const char *buf, size_t count) | |
70 | { | |
71 | int ret; | |
72 | ||
73 | if (prof_on) | |
74 | return -EEXIST; | |
75 | /* | |
76 | * This eventually calls into get_option() which | |
77 | * has a ton of callers and is not const. It is | |
78 | * easiest to cast it away here. | |
79 | */ | |
80 | profile_setup((char *)buf); | |
81 | ret = profile_init(); | |
82 | if (ret) | |
83 | return ret; | |
84 | ret = create_proc_profile(); | |
85 | if (ret) | |
86 | return ret; | |
87 | return count; | |
88 | } | |
89 | KERNEL_ATTR_RW(profiling); | |
90 | #endif | |
91 | ||
c330dda9 | 92 | #ifdef CONFIG_KEXEC |
386f275f KS |
93 | static ssize_t kexec_loaded_show(struct kobject *kobj, |
94 | struct kobj_attribute *attr, char *buf) | |
c330dda9 | 95 | { |
386f275f | 96 | return sprintf(buf, "%d\n", !!kexec_image); |
c330dda9 JM |
97 | } |
98 | KERNEL_ATTR_RO(kexec_loaded); | |
99 | ||
386f275f KS |
100 | static ssize_t kexec_crash_loaded_show(struct kobject *kobj, |
101 | struct kobj_attribute *attr, char *buf) | |
c330dda9 | 102 | { |
386f275f | 103 | return sprintf(buf, "%d\n", !!kexec_crash_image); |
c330dda9 JM |
104 | } |
105 | KERNEL_ATTR_RO(kexec_crash_loaded); | |
fd59d231 | 106 | |
06a7f711 AW |
107 | static ssize_t kexec_crash_size_show(struct kobject *kobj, |
108 | struct kobj_attribute *attr, char *buf) | |
109 | { | |
110 | return sprintf(buf, "%zu\n", crash_get_memory_size()); | |
111 | } | |
112 | static ssize_t kexec_crash_size_store(struct kobject *kobj, | |
113 | struct kobj_attribute *attr, | |
114 | const char *buf, size_t count) | |
115 | { | |
116 | unsigned long cnt; | |
117 | int ret; | |
118 | ||
6072ddc8 | 119 | if (kstrtoul(buf, 0, &cnt)) |
06a7f711 AW |
120 | return -EINVAL; |
121 | ||
122 | ret = crash_shrink_memory(cnt); | |
123 | return ret < 0 ? ret : count; | |
124 | } | |
125 | KERNEL_ATTR_RW(kexec_crash_size); | |
126 | ||
386f275f KS |
127 | static ssize_t vmcoreinfo_show(struct kobject *kobj, |
128 | struct kobj_attribute *attr, char *buf) | |
fd59d231 | 129 | { |
386f275f | 130 | return sprintf(buf, "%lx %x\n", |
fd59d231 | 131 | paddr_vmcoreinfo_note(), |
77019967 | 132 | (unsigned int)sizeof(vmcoreinfo_note)); |
fd59d231 KO |
133 | } |
134 | KERNEL_ATTR_RO(vmcoreinfo); | |
135 | ||
c330dda9 JM |
136 | #endif /* CONFIG_KEXEC */ |
137 | ||
088ab0b4 LN |
138 | /* whether file capabilities are enabled */ |
139 | static ssize_t fscaps_show(struct kobject *kobj, | |
140 | struct kobj_attribute *attr, char *buf) | |
141 | { | |
142 | return sprintf(buf, "%d\n", file_caps_enabled); | |
143 | } | |
144 | KERNEL_ATTR_RO(fscaps); | |
145 | ||
3705b88d AM |
146 | int rcu_expedited; |
147 | static ssize_t rcu_expedited_show(struct kobject *kobj, | |
148 | struct kobj_attribute *attr, char *buf) | |
149 | { | |
150 | return sprintf(buf, "%d\n", rcu_expedited); | |
151 | } | |
152 | static ssize_t rcu_expedited_store(struct kobject *kobj, | |
153 | struct kobj_attribute *attr, | |
154 | const char *buf, size_t count) | |
155 | { | |
156 | if (kstrtoint(buf, 0, &rcu_expedited)) | |
157 | return -EINVAL; | |
158 | ||
159 | return count; | |
160 | } | |
161 | KERNEL_ATTR_RW(rcu_expedited); | |
162 | ||
da1a679c RM |
163 | /* |
164 | * Make /sys/kernel/notes give the raw contents of our kernel .notes section. | |
165 | */ | |
52f5684c GID |
166 | extern const void __start_notes __weak; |
167 | extern const void __stop_notes __weak; | |
da1a679c RM |
168 | #define notes_size (&__stop_notes - &__start_notes) |
169 | ||
2c3c8bea CW |
170 | static ssize_t notes_read(struct file *filp, struct kobject *kobj, |
171 | struct bin_attribute *bin_attr, | |
da1a679c RM |
172 | char *buf, loff_t off, size_t count) |
173 | { | |
174 | memcpy(buf, &__start_notes + off, count); | |
175 | return count; | |
176 | } | |
177 | ||
178 | static struct bin_attribute notes_attr = { | |
179 | .attr = { | |
180 | .name = "notes", | |
181 | .mode = S_IRUGO, | |
182 | }, | |
183 | .read = ¬es_read, | |
184 | }; | |
185 | ||
0ff21e46 GKH |
186 | struct kobject *kernel_kobj; |
187 | EXPORT_SYMBOL_GPL(kernel_kobj); | |
1da177e4 LT |
188 | |
189 | static struct attribute * kernel_attrs[] = { | |
088ab0b4 | 190 | &fscaps_attr.attr, |
0f76e5ac KS |
191 | &uevent_seqnum_attr.attr, |
192 | &uevent_helper_attr.attr, | |
22b8ce94 DH |
193 | #ifdef CONFIG_PROFILING |
194 | &profiling_attr.attr, | |
195 | #endif | |
c330dda9 JM |
196 | #ifdef CONFIG_KEXEC |
197 | &kexec_loaded_attr.attr, | |
198 | &kexec_crash_loaded_attr.attr, | |
06a7f711 | 199 | &kexec_crash_size_attr.attr, |
fd59d231 | 200 | &vmcoreinfo_attr.attr, |
1da177e4 | 201 | #endif |
3705b88d | 202 | &rcu_expedited_attr.attr, |
1da177e4 LT |
203 | NULL |
204 | }; | |
205 | ||
206 | static struct attribute_group kernel_attr_group = { | |
207 | .attrs = kernel_attrs, | |
208 | }; | |
209 | ||
210 | static int __init ksysfs_init(void) | |
211 | { | |
bd35b93d | 212 | int error; |
1da177e4 | 213 | |
0ff21e46 GKH |
214 | kernel_kobj = kobject_create_and_add("kernel", NULL); |
215 | if (!kernel_kobj) { | |
bd35b93d GKH |
216 | error = -ENOMEM; |
217 | goto exit; | |
218 | } | |
0ff21e46 | 219 | error = sysfs_create_group(kernel_kobj, &kernel_attr_group); |
bd35b93d GKH |
220 | if (error) |
221 | goto kset_exit; | |
222 | ||
223 | if (notes_size > 0) { | |
da1a679c | 224 | notes_attr.size = notes_size; |
0ff21e46 | 225 | error = sysfs_create_bin_file(kernel_kobj, ¬es_attr); |
bd35b93d GKH |
226 | if (error) |
227 | goto group_exit; | |
da1a679c RM |
228 | } |
229 | ||
bd35b93d GKH |
230 | return 0; |
231 | ||
bd35b93d | 232 | group_exit: |
0ff21e46 | 233 | sysfs_remove_group(kernel_kobj, &kernel_attr_group); |
bd35b93d | 234 | kset_exit: |
78a2d906 | 235 | kobject_put(kernel_kobj); |
bd35b93d | 236 | exit: |
1da177e4 LT |
237 | return error; |
238 | } | |
239 | ||
240 | core_initcall(ksysfs_init); |