2 * kernel/ksysfs.c - sysfs attributes in /sys/kernel, which
3 * are not related to any other subsystem
5 * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
7 * This file is release under the GPLv2
11 #include <linux/kobject.h>
12 #include <linux/string.h>
13 #include <linux/sysfs.h>
14 #include <linux/export.h>
15 #include <linux/init.h>
16 #include <linux/kexec.h>
17 #include <linux/profile.h>
18 #include <linux/stat.h>
19 #include <linux/sched.h>
20 #include <linux/capability.h>
22 #include <linux/rcupdate.h> /* rcu_expedited */
24 #define KERNEL_ATTR_RO(_name) \
25 static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
27 #define KERNEL_ATTR_RW(_name) \
28 static struct kobj_attribute _name##_attr = \
29 __ATTR(_name, 0644, _name##_show, _name##_store)
31 /* current uevent sequence number */
32 static ssize_t
uevent_seqnum_show(struct kobject
*kobj
,
33 struct kobj_attribute
*attr
, char *buf
)
35 return sprintf(buf
, "%llu\n", (unsigned long long)uevent_seqnum
);
37 KERNEL_ATTR_RO(uevent_seqnum
);
39 /* uevent helper program, used during early boot */
40 static ssize_t
uevent_helper_show(struct kobject
*kobj
,
41 struct kobj_attribute
*attr
, char *buf
)
43 return sprintf(buf
, "%s\n", uevent_helper
);
45 static ssize_t
uevent_helper_store(struct kobject
*kobj
,
46 struct kobj_attribute
*attr
,
47 const char *buf
, size_t count
)
49 if (count
+1 > UEVENT_HELPER_PATH_LEN
)
51 memcpy(uevent_helper
, buf
, count
);
52 uevent_helper
[count
] = '\0';
53 if (count
&& uevent_helper
[count
-1] == '\n')
54 uevent_helper
[count
-1] = '\0';
57 KERNEL_ATTR_RW(uevent_helper
);
60 #ifdef CONFIG_PROFILING
61 static ssize_t
profiling_show(struct kobject
*kobj
,
62 struct kobj_attribute
*attr
, char *buf
)
64 return sprintf(buf
, "%d\n", prof_on
);
66 static ssize_t
profiling_store(struct kobject
*kobj
,
67 struct kobj_attribute
*attr
,
68 const char *buf
, size_t count
)
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.
79 profile_setup((char *)buf
);
83 ret
= create_proc_profile();
88 KERNEL_ATTR_RW(profiling
);
92 static ssize_t
kexec_loaded_show(struct kobject
*kobj
,
93 struct kobj_attribute
*attr
, char *buf
)
95 return sprintf(buf
, "%d\n", !!kexec_image
);
97 KERNEL_ATTR_RO(kexec_loaded
);
99 static ssize_t
kexec_crash_loaded_show(struct kobject
*kobj
,
100 struct kobj_attribute
*attr
, char *buf
)
102 return sprintf(buf
, "%d\n", !!kexec_crash_image
);
104 KERNEL_ATTR_RO(kexec_crash_loaded
);
106 static ssize_t
kexec_crash_size_show(struct kobject
*kobj
,
107 struct kobj_attribute
*attr
, char *buf
)
109 return sprintf(buf
, "%zu\n", crash_get_memory_size());
111 static ssize_t
kexec_crash_size_store(struct kobject
*kobj
,
112 struct kobj_attribute
*attr
,
113 const char *buf
, size_t count
)
118 if (kstrtoul(buf
, 0, &cnt
))
121 ret
= crash_shrink_memory(cnt
);
122 return ret
< 0 ? ret
: count
;
124 KERNEL_ATTR_RW(kexec_crash_size
);
126 static ssize_t
vmcoreinfo_show(struct kobject
*kobj
,
127 struct kobj_attribute
*attr
, char *buf
)
129 return sprintf(buf
, "%lx %x\n",
130 paddr_vmcoreinfo_note(),
131 (unsigned int)sizeof(vmcoreinfo_note
));
133 KERNEL_ATTR_RO(vmcoreinfo
);
135 #endif /* CONFIG_KEXEC */
137 /* whether file capabilities are enabled */
138 static ssize_t
fscaps_show(struct kobject
*kobj
,
139 struct kobj_attribute
*attr
, char *buf
)
141 return sprintf(buf
, "%d\n", file_caps_enabled
);
143 KERNEL_ATTR_RO(fscaps
);
146 static ssize_t
rcu_expedited_show(struct kobject
*kobj
,
147 struct kobj_attribute
*attr
, char *buf
)
149 return sprintf(buf
, "%d\n", rcu_expedited
);
151 static ssize_t
rcu_expedited_store(struct kobject
*kobj
,
152 struct kobj_attribute
*attr
,
153 const char *buf
, size_t count
)
155 if (kstrtoint(buf
, 0, &rcu_expedited
))
160 KERNEL_ATTR_RW(rcu_expedited
);
163 * Make /sys/kernel/notes give the raw contents of our kernel .notes section.
165 extern const void __start_notes
__attribute__((weak
));
166 extern const void __stop_notes
__attribute__((weak
));
167 #define notes_size (&__stop_notes - &__start_notes)
169 static ssize_t
notes_read(struct file
*filp
, struct kobject
*kobj
,
170 struct bin_attribute
*bin_attr
,
171 char *buf
, loff_t off
, size_t count
)
173 memcpy(buf
, &__start_notes
+ off
, count
);
177 static struct bin_attribute notes_attr
= {
185 struct kobject
*kernel_kobj
;
186 EXPORT_SYMBOL_GPL(kernel_kobj
);
188 static struct attribute
* kernel_attrs
[] = {
190 &uevent_seqnum_attr
.attr
,
191 &uevent_helper_attr
.attr
,
192 #ifdef CONFIG_PROFILING
193 &profiling_attr
.attr
,
196 &kexec_loaded_attr
.attr
,
197 &kexec_crash_loaded_attr
.attr
,
198 &kexec_crash_size_attr
.attr
,
199 &vmcoreinfo_attr
.attr
,
201 &rcu_expedited_attr
.attr
,
205 static struct attribute_group kernel_attr_group
= {
206 .attrs
= kernel_attrs
,
209 static int __init
ksysfs_init(void)
213 kernel_kobj
= kobject_create_and_add("kernel", NULL
);
218 error
= sysfs_create_group(kernel_kobj
, &kernel_attr_group
);
222 if (notes_size
> 0) {
223 notes_attr
.size
= notes_size
;
224 error
= sysfs_create_bin_file(kernel_kobj
, ¬es_attr
);
232 sysfs_remove_group(kernel_kobj
, &kernel_attr_group
);
234 kobject_put(kernel_kobj
);
239 core_initcall(ksysfs_init
);