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
 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>
 21#include <linux/compiler.h>
 22
 23#include <linux/rcupdate.h>	/* rcu_expedited and rcu_normal */
 24
 25#define KERNEL_ATTR_RO(_name) \
 26static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
 27
 28#define KERNEL_ATTR_RW(_name) \
 29static struct kobj_attribute _name##_attr = \
 30	__ATTR(_name, 0644, _name##_show, _name##_store)
 31
 
 32/* current uevent sequence number */
 33static ssize_t uevent_seqnum_show(struct kobject *kobj,
 34				  struct kobj_attribute *attr, char *buf)
 35{
 36	return sprintf(buf, "%llu\n", (unsigned long long)uevent_seqnum);
 37}
 38KERNEL_ATTR_RO(uevent_seqnum);
 39
 40#ifdef CONFIG_UEVENT_HELPER
 41/* uevent helper program, used during early boot */
 42static ssize_t uevent_helper_show(struct kobject *kobj,
 43				  struct kobj_attribute *attr, char *buf)
 44{
 45	return sprintf(buf, "%s\n", uevent_helper);
 46}
 47static ssize_t uevent_helper_store(struct kobject *kobj,
 48				   struct kobj_attribute *attr,
 49				   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	uevent_helper[count] = '\0';
 55	if (count && uevent_helper[count-1] == '\n')
 56		uevent_helper[count-1] = '\0';
 57	return count;
 58}
 59KERNEL_ATTR_RW(uevent_helper);
 60#endif
 61
 62#ifdef CONFIG_PROFILING
 63static ssize_t profiling_show(struct kobject *kobj,
 64				  struct kobj_attribute *attr, char *buf)
 65{
 66	return sprintf(buf, "%d\n", prof_on);
 67}
 68static ssize_t profiling_store(struct kobject *kobj,
 69				   struct kobj_attribute *attr,
 70				   const char *buf, size_t count)
 71{
 72	int ret;
 73
 74	if (prof_on)
 75		return -EEXIST;
 76	/*
 77	 * This eventually calls into get_option() which
 78	 * has a ton of callers and is not const.  It is
 79	 * easiest to cast it away here.
 80	 */
 81	profile_setup((char *)buf);
 82	ret = profile_init();
 83	if (ret)
 84		return ret;
 85	ret = create_proc_profile();
 86	if (ret)
 87		return ret;
 88	return count;
 89}
 90KERNEL_ATTR_RW(profiling);
 91#endif
 92
 93#ifdef CONFIG_KEXEC_CORE
 94static ssize_t kexec_loaded_show(struct kobject *kobj,
 95				 struct kobj_attribute *attr, char *buf)
 96{
 97	return sprintf(buf, "%d\n", !!kexec_image);
 98}
 99KERNEL_ATTR_RO(kexec_loaded);
100
101static ssize_t kexec_crash_loaded_show(struct kobject *kobj,
102				       struct kobj_attribute *attr, char *buf)
103{
104	return sprintf(buf, "%d\n", !!kexec_crash_image);
105}
106KERNEL_ATTR_RO(kexec_crash_loaded);
107
108static ssize_t kexec_crash_size_show(struct kobject *kobj,
109				       struct kobj_attribute *attr, char *buf)
110{
111	return sprintf(buf, "%zu\n", crash_get_memory_size());
112}
113static ssize_t kexec_crash_size_store(struct kobject *kobj,
114				   struct kobj_attribute *attr,
115				   const char *buf, size_t count)
116{
117	unsigned long cnt;
118	int ret;
119
120	if (kstrtoul(buf, 0, &cnt))
121		return -EINVAL;
122
123	ret = crash_shrink_memory(cnt);
124	return ret < 0 ? ret : count;
125}
126KERNEL_ATTR_RW(kexec_crash_size);
127
128static ssize_t vmcoreinfo_show(struct kobject *kobj,
129			       struct kobj_attribute *attr, char *buf)
130{
131	return sprintf(buf, "%lx %x\n",
132		       paddr_vmcoreinfo_note(),
133		       (unsigned int)sizeof(vmcoreinfo_note));
134}
135KERNEL_ATTR_RO(vmcoreinfo);
136
137#endif /* CONFIG_KEXEC_CORE */
138
139/* whether file capabilities are enabled */
140static ssize_t fscaps_show(struct kobject *kobj,
141				  struct kobj_attribute *attr, char *buf)
142{
143	return sprintf(buf, "%d\n", file_caps_enabled);
144}
145KERNEL_ATTR_RO(fscaps);
146
147#ifndef CONFIG_TINY_RCU
148int rcu_expedited;
149static ssize_t rcu_expedited_show(struct kobject *kobj,
150				  struct kobj_attribute *attr, char *buf)
151{
152	return sprintf(buf, "%d\n", READ_ONCE(rcu_expedited));
153}
154static ssize_t rcu_expedited_store(struct kobject *kobj,
155				   struct kobj_attribute *attr,
156				   const char *buf, size_t count)
157{
158	if (kstrtoint(buf, 0, &rcu_expedited))
159		return -EINVAL;
160
161	return count;
162}
163KERNEL_ATTR_RW(rcu_expedited);
164
165int rcu_normal;
166static ssize_t rcu_normal_show(struct kobject *kobj,
167			       struct kobj_attribute *attr, char *buf)
168{
169	return sprintf(buf, "%d\n", READ_ONCE(rcu_normal));
170}
171static ssize_t rcu_normal_store(struct kobject *kobj,
172				struct kobj_attribute *attr,
173				const char *buf, size_t count)
174{
175	if (kstrtoint(buf, 0, &rcu_normal))
176		return -EINVAL;
177
178	return count;
179}
180KERNEL_ATTR_RW(rcu_normal);
181#endif /* #ifndef CONFIG_TINY_RCU */
182
183/*
184 * Make /sys/kernel/notes give the raw contents of our kernel .notes section.
185 */
186extern const void __start_notes __weak;
187extern const void __stop_notes __weak;
188#define	notes_size (&__stop_notes - &__start_notes)
189
190static ssize_t notes_read(struct file *filp, struct kobject *kobj,
191			  struct bin_attribute *bin_attr,
192			  char *buf, loff_t off, size_t count)
193{
194	memcpy(buf, &__start_notes + off, count);
195	return count;
196}
197
198static struct bin_attribute notes_attr = {
199	.attr = {
200		.name = "notes",
201		.mode = S_IRUGO,
202	},
203	.read = &notes_read,
204};
205
206struct kobject *kernel_kobj;
207EXPORT_SYMBOL_GPL(kernel_kobj);
208
209static struct attribute * kernel_attrs[] = {
210	&fscaps_attr.attr,
 
211	&uevent_seqnum_attr.attr,
212#ifdef CONFIG_UEVENT_HELPER
213	&uevent_helper_attr.attr,
214#endif
215#ifdef CONFIG_PROFILING
216	&profiling_attr.attr,
217#endif
218#ifdef CONFIG_KEXEC_CORE
219	&kexec_loaded_attr.attr,
220	&kexec_crash_loaded_attr.attr,
221	&kexec_crash_size_attr.attr,
222	&vmcoreinfo_attr.attr,
223#endif
224#ifndef CONFIG_TINY_RCU
225	&rcu_expedited_attr.attr,
226	&rcu_normal_attr.attr,
227#endif
228	NULL
229};
230
231static struct attribute_group kernel_attr_group = {
232	.attrs = kernel_attrs,
233};
234
235static int __init ksysfs_init(void)
236{
237	int error;
238
239	kernel_kobj = kobject_create_and_add("kernel", NULL);
240	if (!kernel_kobj) {
241		error = -ENOMEM;
242		goto exit;
243	}
244	error = sysfs_create_group(kernel_kobj, &kernel_attr_group);
245	if (error)
246		goto kset_exit;
247
248	if (notes_size > 0) {
249		notes_attr.size = notes_size;
250		error = sysfs_create_bin_file(kernel_kobj, &notes_attr);
251		if (error)
252			goto group_exit;
253	}
254
255	return 0;
256
257group_exit:
258	sysfs_remove_group(kernel_kobj, &kernel_attr_group);
259kset_exit:
260	kobject_put(kernel_kobj);
261exit:
262	return error;
263}
264
265core_initcall(ksysfs_init);

  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
 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>
 
 
 
 21
 22#define KERNEL_ATTR_RO(_name) \
 23static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
 24
 25#define KERNEL_ATTR_RW(_name) \
 26static struct kobj_attribute _name##_attr = \
 27	__ATTR(_name, 0644, _name##_show, _name##_store)
 28
 29#if defined(CONFIG_HOTPLUG)
 30/* current uevent sequence number */
 31static ssize_t uevent_seqnum_show(struct kobject *kobj,
 32				  struct kobj_attribute *attr, char *buf)
 33{
 34	return sprintf(buf, "%llu\n", (unsigned long long)uevent_seqnum);
 35}
 36KERNEL_ATTR_RO(uevent_seqnum);
 37
 
 38/* uevent helper program, used during early boot */
 39static ssize_t uevent_helper_show(struct kobject *kobj,
 40				  struct kobj_attribute *attr, char *buf)
 41{
 42	return sprintf(buf, "%s\n", uevent_helper);
 43}
 44static ssize_t uevent_helper_store(struct kobject *kobj,
 45				   struct kobj_attribute *attr,
 46				   const char *buf, size_t count)
 47{
 48	if (count+1 > UEVENT_HELPER_PATH_LEN)
 49		return -ENOENT;
 50	memcpy(uevent_helper, buf, count);
 51	uevent_helper[count] = '\0';
 52	if (count && uevent_helper[count-1] == '\n')
 53		uevent_helper[count-1] = '\0';
 54	return count;
 55}
 56KERNEL_ATTR_RW(uevent_helper);
 57#endif
 58
 59#ifdef CONFIG_PROFILING
 60static ssize_t profiling_show(struct kobject *kobj,
 61				  struct kobj_attribute *attr, char *buf)
 62{
 63	return sprintf(buf, "%d\n", prof_on);
 64}
 65static 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}
 87KERNEL_ATTR_RW(profiling);
 88#endif
 89
 90#ifdef CONFIG_KEXEC
 91static ssize_t kexec_loaded_show(struct kobject *kobj,
 92				 struct kobj_attribute *attr, char *buf)
 93{
 94	return sprintf(buf, "%d\n", !!kexec_image);
 95}
 96KERNEL_ATTR_RO(kexec_loaded);
 97
 98static ssize_t kexec_crash_loaded_show(struct kobject *kobj,
 99				       struct kobj_attribute *attr, char *buf)
100{
101	return sprintf(buf, "%d\n", !!kexec_crash_image);
102}
103KERNEL_ATTR_RO(kexec_crash_loaded);
104
105static 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}
110static 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
117	if (strict_strtoul(buf, 0, &cnt))
118		return -EINVAL;
119
120	ret = crash_shrink_memory(cnt);
121	return ret < 0 ? ret : count;
122}
123KERNEL_ATTR_RW(kexec_crash_size);
124
125static ssize_t vmcoreinfo_show(struct kobject *kobj,
126			       struct kobj_attribute *attr, char *buf)
127{
128	return sprintf(buf, "%lx %x\n",
129		       paddr_vmcoreinfo_note(),
130		       (unsigned int)vmcoreinfo_max_size);
131}
132KERNEL_ATTR_RO(vmcoreinfo);
133
134#endif /* CONFIG_KEXEC */
135
136/* whether file capabilities are enabled */
137static ssize_t fscaps_show(struct kobject *kobj,
138				  struct kobj_attribute *attr, char *buf)
139{
140	return sprintf(buf, "%d\n", file_caps_enabled);
141}
142KERNEL_ATTR_RO(fscaps);
143
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
144/*
145 * Make /sys/kernel/notes give the raw contents of our kernel .notes section.
146 */
147extern const void __start_notes __attribute__((weak));
148extern const void __stop_notes __attribute__((weak));
149#define	notes_size (&__stop_notes - &__start_notes)
150
151static ssize_t notes_read(struct file *filp, struct kobject *kobj,
152			  struct bin_attribute *bin_attr,
153			  char *buf, loff_t off, size_t count)
154{
155	memcpy(buf, &__start_notes + off, count);
156	return count;
157}
158
159static struct bin_attribute notes_attr = {
160	.attr = {
161		.name = "notes",
162		.mode = S_IRUGO,
163	},
164	.read = &notes_read,
165};
166
167struct kobject *kernel_kobj;
168EXPORT_SYMBOL_GPL(kernel_kobj);
169
170static struct attribute * kernel_attrs[] = {
171	&fscaps_attr.attr,
172#if defined(CONFIG_HOTPLUG)
173	&uevent_seqnum_attr.attr,
 
174	&uevent_helper_attr.attr,
175#endif
176#ifdef CONFIG_PROFILING
177	&profiling_attr.attr,
178#endif
179#ifdef CONFIG_KEXEC
180	&kexec_loaded_attr.attr,
181	&kexec_crash_loaded_attr.attr,
182	&kexec_crash_size_attr.attr,
183	&vmcoreinfo_attr.attr,
 
 
 
 
184#endif
185	NULL
186};
187
188static struct attribute_group kernel_attr_group = {
189	.attrs = kernel_attrs,
190};
191
192static int __init ksysfs_init(void)
193{
194	int error;
195
196	kernel_kobj = kobject_create_and_add("kernel", NULL);
197	if (!kernel_kobj) {
198		error = -ENOMEM;
199		goto exit;
200	}
201	error = sysfs_create_group(kernel_kobj, &kernel_attr_group);
202	if (error)
203		goto kset_exit;
204
205	if (notes_size > 0) {
206		notes_attr.size = notes_size;
207		error = sysfs_create_bin_file(kernel_kobj, &notes_attr);
208		if (error)
209			goto group_exit;
210	}
211
212	return 0;
213
214group_exit:
215	sysfs_remove_group(kernel_kobj, &kernel_attr_group);
216kset_exit:
217	kobject_put(kernel_kobj);
218exit:
219	return error;
220}
221
222core_initcall(ksysfs_init);