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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 <[email protected]> | |
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 | |
5a9be7c6 | 23 | #include <linux/rcupdate.h> /* rcu_expedited and rcu_normal */ |
7a754743 | 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 | ||
86d56134 | 40 | #ifdef CONFIG_UEVENT_HELPER |
af665852 | 41 | /* uevent helper program, used during early boot */ |
386f275f KS |
42 | static ssize_t uevent_helper_show(struct kobject *kobj, |
43 | struct kobj_attribute *attr, char *buf) | |
0f76e5ac | 44 | { |
386f275f | 45 | return sprintf(buf, "%s\n", uevent_helper); |
0f76e5ac | 46 | } |
386f275f KS |
47 | static ssize_t uevent_helper_store(struct kobject *kobj, |
48 | struct kobj_attribute *attr, | |
49 | const char *buf, size_t count) | |
0f76e5ac | 50 | { |
312c004d | 51 | if (count+1 > UEVENT_HELPER_PATH_LEN) |
0f76e5ac | 52 | return -ENOENT; |
386f275f | 53 | memcpy(uevent_helper, buf, count); |
312c004d KS |
54 | uevent_helper[count] = '\0'; |
55 | if (count && uevent_helper[count-1] == '\n') | |
56 | uevent_helper[count-1] = '\0'; | |
0f76e5ac KS |
57 | return count; |
58 | } | |
59 | KERNEL_ATTR_RW(uevent_helper); | |
86d56134 | 60 | #endif |
1da177e4 | 61 | |
22b8ce94 DH |
62 | #ifdef CONFIG_PROFILING |
63 | static ssize_t profiling_show(struct kobject *kobj, | |
64 | struct kobj_attribute *attr, char *buf) | |
65 | { | |
66 | return sprintf(buf, "%d\n", prof_on); | |
67 | } | |
68 | static ssize_t profiling_store(struct kobject *kobj, | |
69 | struct kobj_attribute *attr, | |
70 | const char *buf, size_t count) | |
71 | { | |
72 | int ret; | |
73 | ||
74 | if (prof_on) | |
75 | return -EEXIST; | |
76 | /* | |
77 | * This eventually calls into get_option() which | |
78 | * has a ton of callers and is not const. It is | |
79 | * easiest to cast it away here. | |
80 | */ | |
81 | profile_setup((char *)buf); | |
82 | ret = profile_init(); | |
83 | if (ret) | |
84 | return ret; | |
85 | ret = create_proc_profile(); | |
86 | if (ret) | |
87 | return ret; | |
88 | return count; | |
89 | } | |
90 | KERNEL_ATTR_RW(profiling); | |
91 | #endif | |
92 | ||
2965faa5 | 93 | #ifdef CONFIG_KEXEC_CORE |
386f275f KS |
94 | static ssize_t kexec_loaded_show(struct kobject *kobj, |
95 | struct kobj_attribute *attr, char *buf) | |
c330dda9 | 96 | { |
386f275f | 97 | return sprintf(buf, "%d\n", !!kexec_image); |
c330dda9 JM |
98 | } |
99 | KERNEL_ATTR_RO(kexec_loaded); | |
100 | ||
386f275f KS |
101 | static ssize_t kexec_crash_loaded_show(struct kobject *kobj, |
102 | struct kobj_attribute *attr, char *buf) | |
c330dda9 | 103 | { |
21db79e8 | 104 | return sprintf(buf, "%d\n", kexec_crash_loaded()); |
c330dda9 JM |
105 | } |
106 | KERNEL_ATTR_RO(kexec_crash_loaded); | |
fd59d231 | 107 | |
06a7f711 AW |
108 | static ssize_t kexec_crash_size_show(struct kobject *kobj, |
109 | struct kobj_attribute *attr, char *buf) | |
110 | { | |
111 | return sprintf(buf, "%zu\n", crash_get_memory_size()); | |
112 | } | |
113 | static ssize_t kexec_crash_size_store(struct kobject *kobj, | |
114 | struct kobj_attribute *attr, | |
115 | const char *buf, size_t count) | |
116 | { | |
117 | unsigned long cnt; | |
118 | int ret; | |
119 | ||
6072ddc8 | 120 | if (kstrtoul(buf, 0, &cnt)) |
06a7f711 AW |
121 | return -EINVAL; |
122 | ||
123 | ret = crash_shrink_memory(cnt); | |
124 | return ret < 0 ? ret : count; | |
125 | } | |
126 | KERNEL_ATTR_RW(kexec_crash_size); | |
127 | ||
692f66f2 HB |
128 | #endif /* CONFIG_KEXEC_CORE */ |
129 | ||
130 | #ifdef CONFIG_CRASH_CORE | |
131 | ||
386f275f KS |
132 | static ssize_t vmcoreinfo_show(struct kobject *kobj, |
133 | struct kobj_attribute *attr, char *buf) | |
fd59d231 | 134 | { |
dae28018 RK |
135 | phys_addr_t vmcore_base = paddr_vmcoreinfo_note(); |
136 | return sprintf(buf, "%pa %x\n", &vmcore_base, | |
203e9e41 | 137 | (unsigned int)VMCOREINFO_NOTE_SIZE); |
fd59d231 KO |
138 | } |
139 | KERNEL_ATTR_RO(vmcoreinfo); | |
140 | ||
692f66f2 | 141 | #endif /* CONFIG_CRASH_CORE */ |
c330dda9 | 142 | |
088ab0b4 LN |
143 | /* whether file capabilities are enabled */ |
144 | static ssize_t fscaps_show(struct kobject *kobj, | |
145 | struct kobj_attribute *attr, char *buf) | |
146 | { | |
147 | return sprintf(buf, "%d\n", file_caps_enabled); | |
148 | } | |
149 | KERNEL_ATTR_RO(fscaps); | |
150 | ||
79cfea02 | 151 | #ifndef CONFIG_TINY_RCU |
3705b88d AM |
152 | int rcu_expedited; |
153 | static ssize_t rcu_expedited_show(struct kobject *kobj, | |
154 | struct kobj_attribute *attr, char *buf) | |
155 | { | |
5a9be7c6 | 156 | return sprintf(buf, "%d\n", READ_ONCE(rcu_expedited)); |
3705b88d AM |
157 | } |
158 | static ssize_t rcu_expedited_store(struct kobject *kobj, | |
159 | struct kobj_attribute *attr, | |
160 | const char *buf, size_t count) | |
161 | { | |
162 | if (kstrtoint(buf, 0, &rcu_expedited)) | |
163 | return -EINVAL; | |
164 | ||
165 | return count; | |
166 | } | |
167 | KERNEL_ATTR_RW(rcu_expedited); | |
168 | ||
5a9be7c6 PM |
169 | int rcu_normal; |
170 | static ssize_t rcu_normal_show(struct kobject *kobj, | |
171 | struct kobj_attribute *attr, char *buf) | |
172 | { | |
173 | return sprintf(buf, "%d\n", READ_ONCE(rcu_normal)); | |
174 | } | |
175 | static ssize_t rcu_normal_store(struct kobject *kobj, | |
176 | struct kobj_attribute *attr, | |
177 | const char *buf, size_t count) | |
178 | { | |
179 | if (kstrtoint(buf, 0, &rcu_normal)) | |
180 | return -EINVAL; | |
181 | ||
182 | return count; | |
183 | } | |
184 | KERNEL_ATTR_RW(rcu_normal); | |
79cfea02 | 185 | #endif /* #ifndef CONFIG_TINY_RCU */ |
5a9be7c6 | 186 | |
da1a679c RM |
187 | /* |
188 | * Make /sys/kernel/notes give the raw contents of our kernel .notes section. | |
189 | */ | |
52f5684c GID |
190 | extern const void __start_notes __weak; |
191 | extern const void __stop_notes __weak; | |
da1a679c RM |
192 | #define notes_size (&__stop_notes - &__start_notes) |
193 | ||
2c3c8bea CW |
194 | static ssize_t notes_read(struct file *filp, struct kobject *kobj, |
195 | struct bin_attribute *bin_attr, | |
da1a679c RM |
196 | char *buf, loff_t off, size_t count) |
197 | { | |
198 | memcpy(buf, &__start_notes + off, count); | |
199 | return count; | |
200 | } | |
201 | ||
738bc38d | 202 | static struct bin_attribute notes_attr __ro_after_init = { |
da1a679c RM |
203 | .attr = { |
204 | .name = "notes", | |
205 | .mode = S_IRUGO, | |
206 | }, | |
207 | .read = ¬es_read, | |
208 | }; | |
209 | ||
0ff21e46 GKH |
210 | struct kobject *kernel_kobj; |
211 | EXPORT_SYMBOL_GPL(kernel_kobj); | |
1da177e4 LT |
212 | |
213 | static struct attribute * kernel_attrs[] = { | |
088ab0b4 | 214 | &fscaps_attr.attr, |
0f76e5ac | 215 | &uevent_seqnum_attr.attr, |
86d56134 | 216 | #ifdef CONFIG_UEVENT_HELPER |
0f76e5ac | 217 | &uevent_helper_attr.attr, |
86d56134 | 218 | #endif |
22b8ce94 DH |
219 | #ifdef CONFIG_PROFILING |
220 | &profiling_attr.attr, | |
221 | #endif | |
2965faa5 | 222 | #ifdef CONFIG_KEXEC_CORE |
c330dda9 JM |
223 | &kexec_loaded_attr.attr, |
224 | &kexec_crash_loaded_attr.attr, | |
06a7f711 | 225 | &kexec_crash_size_attr.attr, |
692f66f2 HB |
226 | #endif |
227 | #ifdef CONFIG_CRASH_CORE | |
fd59d231 | 228 | &vmcoreinfo_attr.attr, |
1da177e4 | 229 | #endif |
79cfea02 | 230 | #ifndef CONFIG_TINY_RCU |
3705b88d | 231 | &rcu_expedited_attr.attr, |
5a9be7c6 | 232 | &rcu_normal_attr.attr, |
79cfea02 | 233 | #endif |
1da177e4 LT |
234 | NULL |
235 | }; | |
236 | ||
9dcdcea1 | 237 | static const struct attribute_group kernel_attr_group = { |
1da177e4 LT |
238 | .attrs = kernel_attrs, |
239 | }; | |
240 | ||
241 | static int __init ksysfs_init(void) | |
242 | { | |
bd35b93d | 243 | int error; |
1da177e4 | 244 | |
0ff21e46 GKH |
245 | kernel_kobj = kobject_create_and_add("kernel", NULL); |
246 | if (!kernel_kobj) { | |
bd35b93d GKH |
247 | error = -ENOMEM; |
248 | goto exit; | |
249 | } | |
0ff21e46 | 250 | error = sysfs_create_group(kernel_kobj, &kernel_attr_group); |
bd35b93d GKH |
251 | if (error) |
252 | goto kset_exit; | |
253 | ||
254 | if (notes_size > 0) { | |
da1a679c | 255 | notes_attr.size = notes_size; |
0ff21e46 | 256 | error = sysfs_create_bin_file(kernel_kobj, ¬es_attr); |
bd35b93d GKH |
257 | if (error) |
258 | goto group_exit; | |
da1a679c RM |
259 | } |
260 | ||
bd35b93d GKH |
261 | return 0; |
262 | ||
bd35b93d | 263 | group_exit: |
0ff21e46 | 264 | sysfs_remove_group(kernel_kobj, &kernel_attr_group); |
bd35b93d | 265 | kset_exit: |
78a2d906 | 266 | kobject_put(kernel_kobj); |
bd35b93d | 267 | exit: |
1da177e4 LT |
268 | return error; |
269 | } | |
270 | ||
271 | core_initcall(ksysfs_init); |