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