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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 <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 | ||
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; |
63d9c273 MT |
53 | if (!capable(CAP_SYS_ADMIN)) |
54 | return -EPERM; | |
386f275f | 55 | memcpy(uevent_helper, buf, count); |
312c004d KS |
56 | uevent_helper[count] = '\0'; |
57 | if (count && uevent_helper[count-1] == '\n') | |
58 | uevent_helper[count-1] = '\0'; | |
0f76e5ac KS |
59 | return count; |
60 | } | |
61 | KERNEL_ATTR_RW(uevent_helper); | |
86d56134 | 62 | #endif |
1da177e4 | 63 | |
22b8ce94 DH |
64 | #ifdef CONFIG_PROFILING |
65 | static ssize_t profiling_show(struct kobject *kobj, | |
66 | struct kobj_attribute *attr, char *buf) | |
67 | { | |
68 | return sprintf(buf, "%d\n", prof_on); | |
69 | } | |
70 | static ssize_t profiling_store(struct kobject *kobj, | |
71 | struct kobj_attribute *attr, | |
72 | const char *buf, size_t count) | |
73 | { | |
74 | int ret; | |
75 | ||
76 | if (prof_on) | |
77 | return -EEXIST; | |
78 | /* | |
79 | * This eventually calls into get_option() which | |
80 | * has a ton of callers and is not const. It is | |
81 | * easiest to cast it away here. | |
82 | */ | |
83 | profile_setup((char *)buf); | |
84 | ret = profile_init(); | |
85 | if (ret) | |
86 | return ret; | |
87 | ret = create_proc_profile(); | |
88 | if (ret) | |
89 | return ret; | |
90 | return count; | |
91 | } | |
92 | KERNEL_ATTR_RW(profiling); | |
93 | #endif | |
94 | ||
c330dda9 | 95 | #ifdef CONFIG_KEXEC |
386f275f KS |
96 | static ssize_t kexec_loaded_show(struct kobject *kobj, |
97 | struct kobj_attribute *attr, char *buf) | |
c330dda9 | 98 | { |
386f275f | 99 | return sprintf(buf, "%d\n", !!kexec_image); |
c330dda9 JM |
100 | } |
101 | KERNEL_ATTR_RO(kexec_loaded); | |
102 | ||
386f275f KS |
103 | static ssize_t kexec_crash_loaded_show(struct kobject *kobj, |
104 | struct kobj_attribute *attr, char *buf) | |
c330dda9 | 105 | { |
386f275f | 106 | return sprintf(buf, "%d\n", !!kexec_crash_image); |
c330dda9 JM |
107 | } |
108 | KERNEL_ATTR_RO(kexec_crash_loaded); | |
fd59d231 | 109 | |
06a7f711 AW |
110 | static ssize_t kexec_crash_size_show(struct kobject *kobj, |
111 | struct kobj_attribute *attr, char *buf) | |
112 | { | |
113 | return sprintf(buf, "%zu\n", crash_get_memory_size()); | |
114 | } | |
115 | static ssize_t kexec_crash_size_store(struct kobject *kobj, | |
116 | struct kobj_attribute *attr, | |
117 | const char *buf, size_t count) | |
118 | { | |
119 | unsigned long cnt; | |
120 | int ret; | |
121 | ||
6072ddc8 | 122 | if (kstrtoul(buf, 0, &cnt)) |
06a7f711 AW |
123 | return -EINVAL; |
124 | ||
125 | ret = crash_shrink_memory(cnt); | |
126 | return ret < 0 ? ret : count; | |
127 | } | |
128 | KERNEL_ATTR_RW(kexec_crash_size); | |
129 | ||
386f275f KS |
130 | static ssize_t vmcoreinfo_show(struct kobject *kobj, |
131 | struct kobj_attribute *attr, char *buf) | |
fd59d231 | 132 | { |
386f275f | 133 | return sprintf(buf, "%lx %x\n", |
fd59d231 | 134 | paddr_vmcoreinfo_note(), |
77019967 | 135 | (unsigned int)sizeof(vmcoreinfo_note)); |
fd59d231 KO |
136 | } |
137 | KERNEL_ATTR_RO(vmcoreinfo); | |
138 | ||
c330dda9 JM |
139 | #endif /* CONFIG_KEXEC */ |
140 | ||
088ab0b4 LN |
141 | /* whether file capabilities are enabled */ |
142 | static ssize_t fscaps_show(struct kobject *kobj, | |
143 | struct kobj_attribute *attr, char *buf) | |
144 | { | |
145 | return sprintf(buf, "%d\n", file_caps_enabled); | |
146 | } | |
147 | KERNEL_ATTR_RO(fscaps); | |
148 | ||
3705b88d AM |
149 | int rcu_expedited; |
150 | static ssize_t rcu_expedited_show(struct kobject *kobj, | |
151 | struct kobj_attribute *attr, char *buf) | |
152 | { | |
153 | return sprintf(buf, "%d\n", rcu_expedited); | |
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 | ||
da1a679c RM |
166 | /* |
167 | * Make /sys/kernel/notes give the raw contents of our kernel .notes section. | |
168 | */ | |
52f5684c GID |
169 | extern const void __start_notes __weak; |
170 | extern const void __stop_notes __weak; | |
da1a679c RM |
171 | #define notes_size (&__stop_notes - &__start_notes) |
172 | ||
2c3c8bea CW |
173 | static ssize_t notes_read(struct file *filp, struct kobject *kobj, |
174 | struct bin_attribute *bin_attr, | |
da1a679c RM |
175 | char *buf, loff_t off, size_t count) |
176 | { | |
177 | memcpy(buf, &__start_notes + off, count); | |
178 | return count; | |
179 | } | |
180 | ||
63d9c273 | 181 | static bin_attribute_no_const notes_attr __read_only = { |
da1a679c RM |
182 | .attr = { |
183 | .name = "notes", | |
184 | .mode = S_IRUGO, | |
185 | }, | |
186 | .read = ¬es_read, | |
187 | }; | |
188 | ||
0ff21e46 GKH |
189 | struct kobject *kernel_kobj; |
190 | EXPORT_SYMBOL_GPL(kernel_kobj); | |
1da177e4 LT |
191 | |
192 | static struct attribute * kernel_attrs[] = { | |
088ab0b4 | 193 | &fscaps_attr.attr, |
0f76e5ac | 194 | &uevent_seqnum_attr.attr, |
86d56134 | 195 | #ifdef CONFIG_UEVENT_HELPER |
0f76e5ac | 196 | &uevent_helper_attr.attr, |
86d56134 | 197 | #endif |
22b8ce94 DH |
198 | #ifdef CONFIG_PROFILING |
199 | &profiling_attr.attr, | |
200 | #endif | |
c330dda9 JM |
201 | #ifdef CONFIG_KEXEC |
202 | &kexec_loaded_attr.attr, | |
203 | &kexec_crash_loaded_attr.attr, | |
06a7f711 | 204 | &kexec_crash_size_attr.attr, |
fd59d231 | 205 | &vmcoreinfo_attr.attr, |
1da177e4 | 206 | #endif |
3705b88d | 207 | &rcu_expedited_attr.attr, |
1da177e4 LT |
208 | NULL |
209 | }; | |
210 | ||
211 | static struct attribute_group kernel_attr_group = { | |
212 | .attrs = kernel_attrs, | |
213 | }; | |
214 | ||
215 | static int __init ksysfs_init(void) | |
216 | { | |
bd35b93d | 217 | int error; |
1da177e4 | 218 | |
0ff21e46 GKH |
219 | kernel_kobj = kobject_create_and_add("kernel", NULL); |
220 | if (!kernel_kobj) { | |
bd35b93d GKH |
221 | error = -ENOMEM; |
222 | goto exit; | |
223 | } | |
0ff21e46 | 224 | error = sysfs_create_group(kernel_kobj, &kernel_attr_group); |
bd35b93d GKH |
225 | if (error) |
226 | goto kset_exit; | |
227 | ||
228 | if (notes_size > 0) { | |
da1a679c | 229 | notes_attr.size = notes_size; |
0ff21e46 | 230 | error = sysfs_create_bin_file(kernel_kobj, ¬es_attr); |
bd35b93d GKH |
231 | if (error) |
232 | goto group_exit; | |
da1a679c RM |
233 | } |
234 | ||
bd35b93d GKH |
235 | return 0; |
236 | ||
bd35b93d | 237 | group_exit: |
0ff21e46 | 238 | sysfs_remove_group(kernel_kobj, &kernel_attr_group); |
bd35b93d | 239 | kset_exit: |
78a2d906 | 240 | kobject_put(kernel_kobj); |
bd35b93d | 241 | exit: |
1da177e4 LT |
242 | return error; |
243 | } | |
244 | ||
245 | core_initcall(ksysfs_init); |