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> |
1da177e4 | 21 | |
7a754743 PG |
22 | #include <linux/rcupdate.h> /* rcu_expedited */ |
23 | ||
1da177e4 | 24 | #define KERNEL_ATTR_RO(_name) \ |
386f275f | 25 | static struct kobj_attribute _name##_attr = __ATTR_RO(_name) |
1da177e4 LT |
26 | |
27 | #define KERNEL_ATTR_RW(_name) \ | |
386f275f | 28 | static struct kobj_attribute _name##_attr = \ |
1da177e4 LT |
29 | __ATTR(_name, 0644, _name##_show, _name##_store) |
30 | ||
0f76e5ac | 31 | /* current uevent sequence number */ |
386f275f KS |
32 | static ssize_t uevent_seqnum_show(struct kobject *kobj, |
33 | struct kobj_attribute *attr, char *buf) | |
1da177e4 | 34 | { |
386f275f | 35 | return sprintf(buf, "%llu\n", (unsigned long long)uevent_seqnum); |
1da177e4 | 36 | } |
0f76e5ac KS |
37 | KERNEL_ATTR_RO(uevent_seqnum); |
38 | ||
af665852 | 39 | /* uevent helper program, used during early boot */ |
386f275f KS |
40 | static ssize_t uevent_helper_show(struct kobject *kobj, |
41 | struct kobj_attribute *attr, char *buf) | |
0f76e5ac | 42 | { |
386f275f | 43 | return sprintf(buf, "%s\n", uevent_helper); |
0f76e5ac | 44 | } |
386f275f KS |
45 | static ssize_t uevent_helper_store(struct kobject *kobj, |
46 | struct kobj_attribute *attr, | |
47 | const char *buf, size_t count) | |
0f76e5ac | 48 | { |
312c004d | 49 | if (count+1 > UEVENT_HELPER_PATH_LEN) |
0f76e5ac | 50 | return -ENOENT; |
386f275f | 51 | memcpy(uevent_helper, buf, count); |
312c004d KS |
52 | uevent_helper[count] = '\0'; |
53 | if (count && uevent_helper[count-1] == '\n') | |
54 | uevent_helper[count-1] = '\0'; | |
0f76e5ac KS |
55 | return count; |
56 | } | |
57 | KERNEL_ATTR_RW(uevent_helper); | |
e3a1a5ec | 58 | |
1da177e4 | 59 | |
22b8ce94 DH |
60 | #ifdef CONFIG_PROFILING |
61 | static ssize_t profiling_show(struct kobject *kobj, | |
62 | struct kobj_attribute *attr, char *buf) | |
63 | { | |
64 | return sprintf(buf, "%d\n", prof_on); | |
65 | } | |
66 | static ssize_t profiling_store(struct kobject *kobj, | |
67 | struct kobj_attribute *attr, | |
68 | const char *buf, size_t count) | |
69 | { | |
70 | int ret; | |
71 | ||
72 | if (prof_on) | |
73 | return -EEXIST; | |
74 | /* | |
75 | * This eventually calls into get_option() which | |
76 | * has a ton of callers and is not const. It is | |
77 | * easiest to cast it away here. | |
78 | */ | |
79 | profile_setup((char *)buf); | |
80 | ret = profile_init(); | |
81 | if (ret) | |
82 | return ret; | |
83 | ret = create_proc_profile(); | |
84 | if (ret) | |
85 | return ret; | |
86 | return count; | |
87 | } | |
88 | KERNEL_ATTR_RW(profiling); | |
89 | #endif | |
90 | ||
c330dda9 | 91 | #ifdef CONFIG_KEXEC |
386f275f KS |
92 | static ssize_t kexec_loaded_show(struct kobject *kobj, |
93 | struct kobj_attribute *attr, char *buf) | |
c330dda9 | 94 | { |
386f275f | 95 | return sprintf(buf, "%d\n", !!kexec_image); |
c330dda9 JM |
96 | } |
97 | KERNEL_ATTR_RO(kexec_loaded); | |
98 | ||
386f275f KS |
99 | static ssize_t kexec_crash_loaded_show(struct kobject *kobj, |
100 | struct kobj_attribute *attr, char *buf) | |
c330dda9 | 101 | { |
386f275f | 102 | return sprintf(buf, "%d\n", !!kexec_crash_image); |
c330dda9 JM |
103 | } |
104 | KERNEL_ATTR_RO(kexec_crash_loaded); | |
fd59d231 | 105 | |
06a7f711 AW |
106 | static ssize_t kexec_crash_size_show(struct kobject *kobj, |
107 | struct kobj_attribute *attr, char *buf) | |
108 | { | |
109 | return sprintf(buf, "%zu\n", crash_get_memory_size()); | |
110 | } | |
111 | static ssize_t kexec_crash_size_store(struct kobject *kobj, | |
112 | struct kobj_attribute *attr, | |
113 | const char *buf, size_t count) | |
114 | { | |
115 | unsigned long cnt; | |
116 | int ret; | |
117 | ||
6072ddc8 | 118 | if (kstrtoul(buf, 0, &cnt)) |
06a7f711 AW |
119 | return -EINVAL; |
120 | ||
121 | ret = crash_shrink_memory(cnt); | |
122 | return ret < 0 ? ret : count; | |
123 | } | |
124 | KERNEL_ATTR_RW(kexec_crash_size); | |
125 | ||
386f275f KS |
126 | static ssize_t vmcoreinfo_show(struct kobject *kobj, |
127 | struct kobj_attribute *attr, char *buf) | |
fd59d231 | 128 | { |
386f275f | 129 | return sprintf(buf, "%lx %x\n", |
fd59d231 | 130 | paddr_vmcoreinfo_note(), |
77019967 | 131 | (unsigned int)sizeof(vmcoreinfo_note)); |
fd59d231 KO |
132 | } |
133 | KERNEL_ATTR_RO(vmcoreinfo); | |
134 | ||
c330dda9 JM |
135 | #endif /* CONFIG_KEXEC */ |
136 | ||
088ab0b4 LN |
137 | /* whether file capabilities are enabled */ |
138 | static ssize_t fscaps_show(struct kobject *kobj, | |
139 | struct kobj_attribute *attr, char *buf) | |
140 | { | |
141 | return sprintf(buf, "%d\n", file_caps_enabled); | |
142 | } | |
143 | KERNEL_ATTR_RO(fscaps); | |
144 | ||
3705b88d AM |
145 | int rcu_expedited; |
146 | static ssize_t rcu_expedited_show(struct kobject *kobj, | |
147 | struct kobj_attribute *attr, char *buf) | |
148 | { | |
149 | return sprintf(buf, "%d\n", rcu_expedited); | |
150 | } | |
151 | static ssize_t rcu_expedited_store(struct kobject *kobj, | |
152 | struct kobj_attribute *attr, | |
153 | const char *buf, size_t count) | |
154 | { | |
155 | if (kstrtoint(buf, 0, &rcu_expedited)) | |
156 | return -EINVAL; | |
157 | ||
158 | return count; | |
159 | } | |
160 | KERNEL_ATTR_RW(rcu_expedited); | |
161 | ||
da1a679c RM |
162 | /* |
163 | * Make /sys/kernel/notes give the raw contents of our kernel .notes section. | |
164 | */ | |
0b1937ac DH |
165 | extern const void __start_notes __attribute__((weak)); |
166 | extern const void __stop_notes __attribute__((weak)); | |
da1a679c RM |
167 | #define notes_size (&__stop_notes - &__start_notes) |
168 | ||
2c3c8bea CW |
169 | static ssize_t notes_read(struct file *filp, struct kobject *kobj, |
170 | struct bin_attribute *bin_attr, | |
da1a679c RM |
171 | char *buf, loff_t off, size_t count) |
172 | { | |
173 | memcpy(buf, &__start_notes + off, count); | |
174 | return count; | |
175 | } | |
176 | ||
177 | static struct bin_attribute notes_attr = { | |
178 | .attr = { | |
179 | .name = "notes", | |
180 | .mode = S_IRUGO, | |
181 | }, | |
182 | .read = ¬es_read, | |
183 | }; | |
184 | ||
0ff21e46 GKH |
185 | struct kobject *kernel_kobj; |
186 | EXPORT_SYMBOL_GPL(kernel_kobj); | |
1da177e4 LT |
187 | |
188 | static struct attribute * kernel_attrs[] = { | |
088ab0b4 | 189 | &fscaps_attr.attr, |
0f76e5ac KS |
190 | &uevent_seqnum_attr.attr, |
191 | &uevent_helper_attr.attr, | |
22b8ce94 DH |
192 | #ifdef CONFIG_PROFILING |
193 | &profiling_attr.attr, | |
194 | #endif | |
c330dda9 JM |
195 | #ifdef CONFIG_KEXEC |
196 | &kexec_loaded_attr.attr, | |
197 | &kexec_crash_loaded_attr.attr, | |
06a7f711 | 198 | &kexec_crash_size_attr.attr, |
fd59d231 | 199 | &vmcoreinfo_attr.attr, |
1da177e4 | 200 | #endif |
3705b88d | 201 | &rcu_expedited_attr.attr, |
1da177e4 LT |
202 | NULL |
203 | }; | |
204 | ||
205 | static struct attribute_group kernel_attr_group = { | |
206 | .attrs = kernel_attrs, | |
207 | }; | |
208 | ||
209 | static int __init ksysfs_init(void) | |
210 | { | |
bd35b93d | 211 | int error; |
1da177e4 | 212 | |
0ff21e46 GKH |
213 | kernel_kobj = kobject_create_and_add("kernel", NULL); |
214 | if (!kernel_kobj) { | |
bd35b93d GKH |
215 | error = -ENOMEM; |
216 | goto exit; | |
217 | } | |
0ff21e46 | 218 | error = sysfs_create_group(kernel_kobj, &kernel_attr_group); |
bd35b93d GKH |
219 | if (error) |
220 | goto kset_exit; | |
221 | ||
222 | if (notes_size > 0) { | |
da1a679c | 223 | notes_attr.size = notes_size; |
0ff21e46 | 224 | error = sysfs_create_bin_file(kernel_kobj, ¬es_attr); |
bd35b93d GKH |
225 | if (error) |
226 | goto group_exit; | |
da1a679c RM |
227 | } |
228 | ||
bd35b93d GKH |
229 | return 0; |
230 | ||
bd35b93d | 231 | group_exit: |
0ff21e46 | 232 | sysfs_remove_group(kernel_kobj, &kernel_attr_group); |
bd35b93d | 233 | kset_exit: |
78a2d906 | 234 | kobject_put(kernel_kobj); |
bd35b93d | 235 | exit: |
1da177e4 LT |
236 | return error; |
237 | } | |
238 | ||
239 | core_initcall(ksysfs_init); |