ksysfs.c 5.6 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3 4 5 6 7 8 9 10 11 12 13
/*
 * kernel/ksysfs.c - sysfs attributes in /sys/kernel, which
 * 		     are not related to any other subsystem
 *
 * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
 * 
 * This file is release under the GPLv2
 *
 */

#include <linux/kobject.h>
#include <linux/string.h>
#include <linux/sysfs.h>
14
#include <linux/export.h>
L
Linus Torvalds 已提交
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>
21
#include <linux/compiler.h>
L
Linus Torvalds 已提交
22

23 24
#include <linux/rcupdate.h>	/* rcu_expedited */

L
Linus Torvalds 已提交
25
#define KERNEL_ATTR_RO(_name) \
26
static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
L
Linus Torvalds 已提交
27 28

#define KERNEL_ATTR_RW(_name) \
29
static struct kobj_attribute _name##_attr = \
L
Linus Torvalds 已提交
30 31
	__ATTR(_name, 0644, _name##_show, _name##_store)

32
/* current uevent sequence number */
33 34
static ssize_t uevent_seqnum_show(struct kobject *kobj,
				  struct kobj_attribute *attr, char *buf)
L
Linus Torvalds 已提交
35
{
36
	return sprintf(buf, "%llu\n", (unsigned long long)uevent_seqnum);
L
Linus Torvalds 已提交
37
}
38 39
KERNEL_ATTR_RO(uevent_seqnum);

40
#ifdef CONFIG_UEVENT_HELPER
41
/* uevent helper program, used during early boot */
42 43
static ssize_t uevent_helper_show(struct kobject *kobj,
				  struct kobj_attribute *attr, char *buf)
44
{
45
	return sprintf(buf, "%s\n", uevent_helper);
46
}
47 48 49
static ssize_t uevent_helper_store(struct kobject *kobj,
				   struct kobj_attribute *attr,
				   const char *buf, size_t count)
50
{
51
	if (count+1 > UEVENT_HELPER_PATH_LEN)
52
		return -ENOENT;
53
	memcpy(uevent_helper, buf, count);
54 55 56
	uevent_helper[count] = '\0';
	if (count && uevent_helper[count-1] == '\n')
		uevent_helper[count-1] = '\0';
57 58 59
	return count;
}
KERNEL_ATTR_RW(uevent_helper);
60
#endif
L
Linus Torvalds 已提交
61

62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92
#ifdef CONFIG_PROFILING
static ssize_t profiling_show(struct kobject *kobj,
				  struct kobj_attribute *attr, char *buf)
{
	return sprintf(buf, "%d\n", prof_on);
}
static ssize_t profiling_store(struct kobject *kobj,
				   struct kobj_attribute *attr,
				   const char *buf, size_t count)
{
	int ret;

	if (prof_on)
		return -EEXIST;
	/*
	 * This eventually calls into get_option() which
	 * has a ton of callers and is not const.  It is
	 * easiest to cast it away here.
	 */
	profile_setup((char *)buf);
	ret = profile_init();
	if (ret)
		return ret;
	ret = create_proc_profile();
	if (ret)
		return ret;
	return count;
}
KERNEL_ATTR_RW(profiling);
#endif

93
#ifdef CONFIG_KEXEC_CORE
94 95
static ssize_t kexec_loaded_show(struct kobject *kobj,
				 struct kobj_attribute *attr, char *buf)
96
{
97
	return sprintf(buf, "%d\n", !!kexec_image);
98 99 100
}
KERNEL_ATTR_RO(kexec_loaded);

101 102
static ssize_t kexec_crash_loaded_show(struct kobject *kobj,
				       struct kobj_attribute *attr, char *buf)
103
{
104
	return sprintf(buf, "%d\n", !!kexec_crash_image);
105 106
}
KERNEL_ATTR_RO(kexec_crash_loaded);
K
Ken'ichi Ohmichi 已提交
107

108 109 110 111 112 113 114 115 116 117 118 119
static ssize_t kexec_crash_size_show(struct kobject *kobj,
				       struct kobj_attribute *attr, char *buf)
{
	return sprintf(buf, "%zu\n", crash_get_memory_size());
}
static ssize_t kexec_crash_size_store(struct kobject *kobj,
				   struct kobj_attribute *attr,
				   const char *buf, size_t count)
{
	unsigned long cnt;
	int ret;

120
	if (kstrtoul(buf, 0, &cnt))
121 122 123 124 125 126 127
		return -EINVAL;

	ret = crash_shrink_memory(cnt);
	return ret < 0 ? ret : count;
}
KERNEL_ATTR_RW(kexec_crash_size);

128 129
static ssize_t vmcoreinfo_show(struct kobject *kobj,
			       struct kobj_attribute *attr, char *buf)
K
Ken'ichi Ohmichi 已提交
130
{
131
	return sprintf(buf, "%lx %x\n",
K
Ken'ichi Ohmichi 已提交
132
		       paddr_vmcoreinfo_note(),
133
		       (unsigned int)sizeof(vmcoreinfo_note));
K
Ken'ichi Ohmichi 已提交
134 135 136
}
KERNEL_ATTR_RO(vmcoreinfo);

137
#endif /* CONFIG_KEXEC_CORE */
138

139 140 141 142 143 144 145 146
/* whether file capabilities are enabled */
static ssize_t fscaps_show(struct kobject *kobj,
				  struct kobj_attribute *attr, char *buf)
{
	return sprintf(buf, "%d\n", file_caps_enabled);
}
KERNEL_ATTR_RO(fscaps);

147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163
int rcu_expedited;
static ssize_t rcu_expedited_show(struct kobject *kobj,
				  struct kobj_attribute *attr, char *buf)
{
	return sprintf(buf, "%d\n", rcu_expedited);
}
static ssize_t rcu_expedited_store(struct kobject *kobj,
				   struct kobj_attribute *attr,
				   const char *buf, size_t count)
{
	if (kstrtoint(buf, 0, &rcu_expedited))
		return -EINVAL;

	return count;
}
KERNEL_ATTR_RW(rcu_expedited);

R
Roland McGrath 已提交
164 165 166
/*
 * Make /sys/kernel/notes give the raw contents of our kernel .notes section.
 */
167 168
extern const void __start_notes __weak;
extern const void __stop_notes __weak;
R
Roland McGrath 已提交
169 170
#define	notes_size (&__stop_notes - &__start_notes)

171 172
static ssize_t notes_read(struct file *filp, struct kobject *kobj,
			  struct bin_attribute *bin_attr,
R
Roland McGrath 已提交
173 174 175 176 177 178 179 180 181 182 183 184 185 186
			  char *buf, loff_t off, size_t count)
{
	memcpy(buf, &__start_notes + off, count);
	return count;
}

static struct bin_attribute notes_attr = {
	.attr = {
		.name = "notes",
		.mode = S_IRUGO,
	},
	.read = &notes_read,
};

187 188
struct kobject *kernel_kobj;
EXPORT_SYMBOL_GPL(kernel_kobj);
L
Linus Torvalds 已提交
189 190

static struct attribute * kernel_attrs[] = {
191
	&fscaps_attr.attr,
192
	&uevent_seqnum_attr.attr,
193
#ifdef CONFIG_UEVENT_HELPER
194
	&uevent_helper_attr.attr,
195
#endif
196 197 198
#ifdef CONFIG_PROFILING
	&profiling_attr.attr,
#endif
199
#ifdef CONFIG_KEXEC_CORE
200 201
	&kexec_loaded_attr.attr,
	&kexec_crash_loaded_attr.attr,
202
	&kexec_crash_size_attr.attr,
K
Ken'ichi Ohmichi 已提交
203
	&vmcoreinfo_attr.attr,
L
Linus Torvalds 已提交
204
#endif
205
	&rcu_expedited_attr.attr,
L
Linus Torvalds 已提交
206 207 208 209 210 211 212 213 214
	NULL
};

static struct attribute_group kernel_attr_group = {
	.attrs = kernel_attrs,
};

static int __init ksysfs_init(void)
{
215
	int error;
L
Linus Torvalds 已提交
216

217 218
	kernel_kobj = kobject_create_and_add("kernel", NULL);
	if (!kernel_kobj) {
219 220 221
		error = -ENOMEM;
		goto exit;
	}
222
	error = sysfs_create_group(kernel_kobj, &kernel_attr_group);
223 224 225 226
	if (error)
		goto kset_exit;

	if (notes_size > 0) {
R
Roland McGrath 已提交
227
		notes_attr.size = notes_size;
228
		error = sysfs_create_bin_file(kernel_kobj, &notes_attr);
229 230
		if (error)
			goto group_exit;
R
Roland McGrath 已提交
231 232
	}

233 234 235
	return 0;

group_exit:
236
	sysfs_remove_group(kernel_kobj, &kernel_attr_group);
237
kset_exit:
238
	kobject_put(kernel_kobj);
239
exit:
L
Linus Torvalds 已提交
240 241 242 243
	return error;
}

core_initcall(ksysfs_init);