Commit | Line | Data |
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468e15fd | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * kernel/ksysfs.c - sysfs attributes in /sys/kernel, which | |
4 | * are not related to any other subsystem | |
5 | * | |
6 | * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org> | |
1da177e4 LT |
7 | */ |
8 | ||
1da177e4 LT |
9 | #include <linux/kobject.h> |
10 | #include <linux/string.h> | |
11 | #include <linux/sysfs.h> | |
9984de1a | 12 | #include <linux/export.h> |
1da177e4 | 13 | #include <linux/init.h> |
c330dda9 | 14 | #include <linux/kexec.h> |
22b8ce94 | 15 | #include <linux/profile.h> |
1596425f | 16 | #include <linux/stat.h> |
5cb350ba | 17 | #include <linux/sched.h> |
088ab0b4 | 18 | #include <linux/capability.h> |
52f5684c | 19 | #include <linux/compiler.h> |
1da177e4 | 20 | |
5a9be7c6 | 21 | #include <linux/rcupdate.h> /* rcu_expedited and rcu_normal */ |
7a754743 | 22 | |
1da177e4 | 23 | #define KERNEL_ATTR_RO(_name) \ |
386f275f | 24 | static struct kobj_attribute _name##_attr = __ATTR_RO(_name) |
1da177e4 LT |
25 | |
26 | #define KERNEL_ATTR_RW(_name) \ | |
a7cd9a53 | 27 | static struct kobj_attribute _name##_attr = __ATTR_RW(_name) |
1da177e4 | 28 | |
0f76e5ac | 29 | /* current uevent sequence number */ |
386f275f KS |
30 | static ssize_t uevent_seqnum_show(struct kobject *kobj, |
31 | struct kobj_attribute *attr, char *buf) | |
1da177e4 | 32 | { |
386f275f | 33 | return sprintf(buf, "%llu\n", (unsigned long long)uevent_seqnum); |
1da177e4 | 34 | } |
0f76e5ac KS |
35 | KERNEL_ATTR_RO(uevent_seqnum); |
36 | ||
86d56134 | 37 | #ifdef CONFIG_UEVENT_HELPER |
af665852 | 38 | /* uevent helper program, used during early boot */ |
386f275f KS |
39 | static ssize_t uevent_helper_show(struct kobject *kobj, |
40 | struct kobj_attribute *attr, char *buf) | |
0f76e5ac | 41 | { |
386f275f | 42 | return sprintf(buf, "%s\n", uevent_helper); |
0f76e5ac | 43 | } |
386f275f KS |
44 | static ssize_t uevent_helper_store(struct kobject *kobj, |
45 | struct kobj_attribute *attr, | |
46 | const char *buf, size_t count) | |
0f76e5ac | 47 | { |
312c004d | 48 | if (count+1 > UEVENT_HELPER_PATH_LEN) |
0f76e5ac | 49 | return -ENOENT; |
386f275f | 50 | memcpy(uevent_helper, buf, count); |
312c004d KS |
51 | uevent_helper[count] = '\0'; |
52 | if (count && uevent_helper[count-1] == '\n') | |
53 | uevent_helper[count-1] = '\0'; | |
0f76e5ac KS |
54 | return count; |
55 | } | |
56 | KERNEL_ATTR_RW(uevent_helper); | |
86d56134 | 57 | #endif |
1da177e4 | 58 | |
22b8ce94 DH |
59 | #ifdef CONFIG_PROFILING |
60 | static ssize_t profiling_show(struct kobject *kobj, | |
61 | struct kobj_attribute *attr, char *buf) | |
62 | { | |
63 | return sprintf(buf, "%d\n", prof_on); | |
64 | } | |
65 | static ssize_t profiling_store(struct kobject *kobj, | |
66 | struct kobj_attribute *attr, | |
67 | const char *buf, size_t count) | |
68 | { | |
69 | int ret; | |
70 | ||
71 | if (prof_on) | |
72 | return -EEXIST; | |
73 | /* | |
74 | * This eventually calls into get_option() which | |
75 | * has a ton of callers and is not const. It is | |
76 | * easiest to cast it away here. | |
77 | */ | |
78 | profile_setup((char *)buf); | |
79 | ret = profile_init(); | |
80 | if (ret) | |
81 | return ret; | |
82 | ret = create_proc_profile(); | |
83 | if (ret) | |
84 | return ret; | |
85 | return count; | |
86 | } | |
87 | KERNEL_ATTR_RW(profiling); | |
88 | #endif | |
89 | ||
2965faa5 | 90 | #ifdef CONFIG_KEXEC_CORE |
386f275f KS |
91 | static ssize_t kexec_loaded_show(struct kobject *kobj, |
92 | struct kobj_attribute *attr, char *buf) | |
c330dda9 | 93 | { |
386f275f | 94 | return sprintf(buf, "%d\n", !!kexec_image); |
c330dda9 JM |
95 | } |
96 | KERNEL_ATTR_RO(kexec_loaded); | |
97 | ||
386f275f KS |
98 | static ssize_t kexec_crash_loaded_show(struct kobject *kobj, |
99 | struct kobj_attribute *attr, char *buf) | |
c330dda9 | 100 | { |
21db79e8 | 101 | return sprintf(buf, "%d\n", kexec_crash_loaded()); |
c330dda9 JM |
102 | } |
103 | KERNEL_ATTR_RO(kexec_crash_loaded); | |
fd59d231 | 104 | |
06a7f711 AW |
105 | static ssize_t kexec_crash_size_show(struct kobject *kobj, |
106 | struct kobj_attribute *attr, char *buf) | |
107 | { | |
108 | return sprintf(buf, "%zu\n", crash_get_memory_size()); | |
109 | } | |
110 | static ssize_t kexec_crash_size_store(struct kobject *kobj, | |
111 | struct kobj_attribute *attr, | |
112 | const char *buf, size_t count) | |
113 | { | |
114 | unsigned long cnt; | |
115 | int ret; | |
116 | ||
6072ddc8 | 117 | if (kstrtoul(buf, 0, &cnt)) |
06a7f711 AW |
118 | return -EINVAL; |
119 | ||
120 | ret = crash_shrink_memory(cnt); | |
121 | return ret < 0 ? ret : count; | |
122 | } | |
123 | KERNEL_ATTR_RW(kexec_crash_size); | |
124 | ||
692f66f2 HB |
125 | #endif /* CONFIG_KEXEC_CORE */ |
126 | ||
127 | #ifdef CONFIG_CRASH_CORE | |
128 | ||
386f275f KS |
129 | static ssize_t vmcoreinfo_show(struct kobject *kobj, |
130 | struct kobj_attribute *attr, char *buf) | |
fd59d231 | 131 | { |
dae28018 RK |
132 | phys_addr_t vmcore_base = paddr_vmcoreinfo_note(); |
133 | return sprintf(buf, "%pa %x\n", &vmcore_base, | |
203e9e41 | 134 | (unsigned int)VMCOREINFO_NOTE_SIZE); |
fd59d231 KO |
135 | } |
136 | KERNEL_ATTR_RO(vmcoreinfo); | |
137 | ||
692f66f2 | 138 | #endif /* CONFIG_CRASH_CORE */ |
c330dda9 | 139 | |
088ab0b4 LN |
140 | /* whether file capabilities are enabled */ |
141 | static ssize_t fscaps_show(struct kobject *kobj, | |
142 | struct kobj_attribute *attr, char *buf) | |
143 | { | |
144 | return sprintf(buf, "%d\n", file_caps_enabled); | |
145 | } | |
146 | KERNEL_ATTR_RO(fscaps); | |
147 | ||
79cfea02 | 148 | #ifndef CONFIG_TINY_RCU |
3705b88d AM |
149 | int rcu_expedited; |
150 | static ssize_t rcu_expedited_show(struct kobject *kobj, | |
151 | struct kobj_attribute *attr, char *buf) | |
152 | { | |
5a9be7c6 | 153 | return sprintf(buf, "%d\n", READ_ONCE(rcu_expedited)); |
3705b88d AM |
154 | } |
155 | static ssize_t rcu_expedited_store(struct kobject *kobj, | |
156 | struct kobj_attribute *attr, | |
157 | const char *buf, size_t count) | |
158 | { | |
159 | if (kstrtoint(buf, 0, &rcu_expedited)) | |
160 | return -EINVAL; | |
161 | ||
162 | return count; | |
163 | } | |
164 | KERNEL_ATTR_RW(rcu_expedited); | |
165 | ||
5a9be7c6 PM |
166 | int rcu_normal; |
167 | static ssize_t rcu_normal_show(struct kobject *kobj, | |
168 | struct kobj_attribute *attr, char *buf) | |
169 | { | |
170 | return sprintf(buf, "%d\n", READ_ONCE(rcu_normal)); | |
171 | } | |
172 | static ssize_t rcu_normal_store(struct kobject *kobj, | |
173 | struct kobj_attribute *attr, | |
174 | const char *buf, size_t count) | |
175 | { | |
176 | if (kstrtoint(buf, 0, &rcu_normal)) | |
177 | return -EINVAL; | |
178 | ||
179 | return count; | |
180 | } | |
181 | KERNEL_ATTR_RW(rcu_normal); | |
79cfea02 | 182 | #endif /* #ifndef CONFIG_TINY_RCU */ |
5a9be7c6 | 183 | |
da1a679c RM |
184 | /* |
185 | * Make /sys/kernel/notes give the raw contents of our kernel .notes section. | |
186 | */ | |
52f5684c GID |
187 | extern const void __start_notes __weak; |
188 | extern const void __stop_notes __weak; | |
da1a679c RM |
189 | #define notes_size (&__stop_notes - &__start_notes) |
190 | ||
2c3c8bea CW |
191 | static ssize_t notes_read(struct file *filp, struct kobject *kobj, |
192 | struct bin_attribute *bin_attr, | |
da1a679c RM |
193 | char *buf, loff_t off, size_t count) |
194 | { | |
195 | memcpy(buf, &__start_notes + off, count); | |
196 | return count; | |
197 | } | |
198 | ||
738bc38d | 199 | static struct bin_attribute notes_attr __ro_after_init = { |
da1a679c RM |
200 | .attr = { |
201 | .name = "notes", | |
202 | .mode = S_IRUGO, | |
203 | }, | |
204 | .read = ¬es_read, | |
205 | }; | |
206 | ||
0ff21e46 GKH |
207 | struct kobject *kernel_kobj; |
208 | EXPORT_SYMBOL_GPL(kernel_kobj); | |
1da177e4 LT |
209 | |
210 | static struct attribute * kernel_attrs[] = { | |
088ab0b4 | 211 | &fscaps_attr.attr, |
0f76e5ac | 212 | &uevent_seqnum_attr.attr, |
86d56134 | 213 | #ifdef CONFIG_UEVENT_HELPER |
0f76e5ac | 214 | &uevent_helper_attr.attr, |
86d56134 | 215 | #endif |
22b8ce94 DH |
216 | #ifdef CONFIG_PROFILING |
217 | &profiling_attr.attr, | |
218 | #endif | |
2965faa5 | 219 | #ifdef CONFIG_KEXEC_CORE |
c330dda9 JM |
220 | &kexec_loaded_attr.attr, |
221 | &kexec_crash_loaded_attr.attr, | |
06a7f711 | 222 | &kexec_crash_size_attr.attr, |
692f66f2 HB |
223 | #endif |
224 | #ifdef CONFIG_CRASH_CORE | |
fd59d231 | 225 | &vmcoreinfo_attr.attr, |
1da177e4 | 226 | #endif |
79cfea02 | 227 | #ifndef CONFIG_TINY_RCU |
3705b88d | 228 | &rcu_expedited_attr.attr, |
5a9be7c6 | 229 | &rcu_normal_attr.attr, |
79cfea02 | 230 | #endif |
1da177e4 LT |
231 | NULL |
232 | }; | |
233 | ||
9dcdcea1 | 234 | static const struct attribute_group kernel_attr_group = { |
1da177e4 LT |
235 | .attrs = kernel_attrs, |
236 | }; | |
237 | ||
238 | static int __init ksysfs_init(void) | |
239 | { | |
bd35b93d | 240 | int error; |
1da177e4 | 241 | |
0ff21e46 GKH |
242 | kernel_kobj = kobject_create_and_add("kernel", NULL); |
243 | if (!kernel_kobj) { | |
bd35b93d GKH |
244 | error = -ENOMEM; |
245 | goto exit; | |
246 | } | |
0ff21e46 | 247 | error = sysfs_create_group(kernel_kobj, &kernel_attr_group); |
bd35b93d GKH |
248 | if (error) |
249 | goto kset_exit; | |
250 | ||
251 | if (notes_size > 0) { | |
da1a679c | 252 | notes_attr.size = notes_size; |
0ff21e46 | 253 | error = sysfs_create_bin_file(kernel_kobj, ¬es_attr); |
bd35b93d GKH |
254 | if (error) |
255 | goto group_exit; | |
da1a679c RM |
256 | } |
257 | ||
bd35b93d GKH |
258 | return 0; |
259 | ||
bd35b93d | 260 | group_exit: |
0ff21e46 | 261 | sysfs_remove_group(kernel_kobj, &kernel_attr_group); |
bd35b93d | 262 | kset_exit: |
78a2d906 | 263 | kobject_put(kernel_kobj); |
bd35b93d | 264 | exit: |
1da177e4 LT |
265 | return error; |
266 | } | |
267 | ||
268 | core_initcall(ksysfs_init); |