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android / kernel / common / d6c552505c0d1719dda42b4af2def0618bd7bf54 / . / kernel / ksysfs.c
blob: 46ba853656f63b7ba1a1e11171b8cdc935666c8d [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]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 <[email protected]>
6 *
7 * This file is release under the GPLv2
8 *
9 */
10
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]11#include <linux/kobject.h>
12#include <linux/string.h>
13#include <linux/sysfs.h>
Paul Gortmaker9984de12011-05-23 14:51:41 -0400[diff] [blame]14#include <linux/export.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]15#include <linux/init.h>
Jeff Moyerc330dda2006-06-23 02:05:07 -0700[diff] [blame]16#include <linux/kexec.h>
Dave Hansen22b8ce92008-10-15 22:01:46 -0700[diff] [blame]17#include <linux/profile.h>
Paul Gortmaker15964252011-07-28 14:22:29 -0400[diff] [blame]18#include <linux/stat.h>
Dhaval Giani5cb350b2007-10-15 17:00:14 +0200[diff] [blame]19#include <linux/sched.h>
Ludwig Nussel088ab0b2011-02-28 15:57:17 +0100[diff] [blame]20#include <linux/capability.h>
Gideon Israel Dsouza52f5684c2014-04-07 15:39:20 -0700[diff] [blame]21#include <linux/compiler.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]22
Paul E. McKenney5a9be7c2015-11-24 15:44:06 -0800[diff] [blame]23#include <linux/rcupdate.h> /* rcu_expedited and rcu_normal */
Paul Gortmaker7a754742014-02-11 16:10:12 -0500[diff] [blame]24
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]25#define KERNEL_ATTR_RO(_name) \
Kay Sievers386f2752007-11-02 13:47:53 +0100[diff] [blame]26static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]27
28#define KERNEL_ATTR_RW(_name) \
Kay Sievers386f2752007-11-02 13:47:53 +0100[diff] [blame]29static struct kobj_attribute _name##_attr = \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]30 __ATTR(_name, 0644, _name##_show, _name##_store)
31
Kay Sievers0f76e5a2005-11-11 04:58:04 +0100[diff] [blame]32/* current uevent sequence number */
Kay Sievers386f2752007-11-02 13:47:53 +0100[diff] [blame]33static ssize_t uevent_seqnum_show(struct kobject *kobj,
34 struct kobj_attribute *attr, char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]35{
Kay Sievers386f2752007-11-02 13:47:53 +0100[diff] [blame]36 return sprintf(buf, "%llu\n", (unsigned long long)uevent_seqnum);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]37}
Kay Sievers0f76e5a2005-11-11 04:58:04 +0100[diff] [blame]38KERNEL_ATTR_RO(uevent_seqnum);
39
Michael Marineau86d56132014-04-10 14:09:31 -0700[diff] [blame]40#ifdef CONFIG_UEVENT_HELPER
Thadeu Lima de Souza Cascardoaf665852010-01-17 19:14:26 -0200[diff] [blame]41/* uevent helper program, used during early boot */
Kay Sievers386f2752007-11-02 13:47:53 +0100[diff] [blame]42static ssize_t uevent_helper_show(struct kobject *kobj,
43 struct kobj_attribute *attr, char *buf)
Kay Sievers0f76e5a2005-11-11 04:58:04 +0100[diff] [blame]44{
Kay Sievers386f2752007-11-02 13:47:53 +0100[diff] [blame]45 return sprintf(buf, "%s\n", uevent_helper);
Kay Sievers0f76e5a2005-11-11 04:58:04 +0100[diff] [blame]46}
Kay Sievers386f2752007-11-02 13:47:53 +0100[diff] [blame]47static ssize_t uevent_helper_store(struct kobject *kobj,
48 struct kobj_attribute *attr,
49 const char *buf, size_t count)
Kay Sievers0f76e5a2005-11-11 04:58:04 +0100[diff] [blame]50{
Kay Sievers312c0042005-11-16 09:00:00 +0100[diff] [blame]51 if (count+1 > UEVENT_HELPER_PATH_LEN)
Kay Sievers0f76e5a2005-11-11 04:58:04 +0100[diff] [blame]52 return -ENOENT;
Kay Sievers386f2752007-11-02 13:47:53 +0100[diff] [blame]53 memcpy(uevent_helper, buf, count);
Kay Sievers312c0042005-11-16 09:00:00 +0100[diff] [blame]54 uevent_helper[count] = '\0';
55 if (count && uevent_helper[count-1] == '\n')
56 uevent_helper[count-1] = '\0';
Kay Sievers0f76e5a2005-11-11 04:58:04 +0100[diff] [blame]57 return count;
58}
59KERNEL_ATTR_RW(uevent_helper);
Michael Marineau86d56132014-04-10 14:09:31 -0700[diff] [blame]60#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]61
Dave Hansen22b8ce92008-10-15 22:01:46 -0700[diff] [blame]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
Dave Young2965faa2015-09-09 15:38:55 -0700[diff] [blame]93#ifdef CONFIG_KEXEC_CORE
Kay Sievers386f2752007-11-02 13:47:53 +0100[diff] [blame]94static ssize_t kexec_loaded_show(struct kobject *kobj,
95 struct kobj_attribute *attr, char *buf)
Jeff Moyerc330dda2006-06-23 02:05:07 -0700[diff] [blame]96{
Kay Sievers386f2752007-11-02 13:47:53 +0100[diff] [blame]97 return sprintf(buf, "%d\n", !!kexec_image);
Jeff Moyerc330dda2006-06-23 02:05:07 -0700[diff] [blame]98}
99KERNEL_ATTR_RO(kexec_loaded);
100
Kay Sievers386f2752007-11-02 13:47:53 +0100[diff] [blame]101static ssize_t kexec_crash_loaded_show(struct kobject *kobj,
102 struct kobj_attribute *attr, char *buf)
Jeff Moyerc330dda2006-06-23 02:05:07 -0700[diff] [blame]103{
Petr Tesarik21db79e2016-08-02 14:06:16 -0700[diff] [blame]104 return sprintf(buf, "%d\n", kexec_crash_loaded());
Jeff Moyerc330dda2006-06-23 02:05:07 -0700[diff] [blame]105}
106KERNEL_ATTR_RO(kexec_crash_loaded);
Ken'ichi Ohmichifd59d232007-10-16 23:27:27 -0700[diff] [blame]107
Amerigo Wang06a7f712009-12-15 16:47:46 -0800[diff] [blame]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
Jingoo Han6072ddc2013-09-12 15:14:07 -0700[diff] [blame]120 if (kstrtoul(buf, 0, &cnt))
Amerigo Wang06a7f712009-12-15 16:47:46 -0800[diff] [blame]121 return -EINVAL;
122
123 ret = crash_shrink_memory(cnt);
124 return ret < 0 ? ret : count;
125}
126KERNEL_ATTR_RW(kexec_crash_size);
127
Hari Bathini692f66f2017-05-08 15:56:18 -0700[diff] [blame]128#endif /* CONFIG_KEXEC_CORE */
129
130#ifdef CONFIG_CRASH_CORE
131
Kay Sievers386f2752007-11-02 13:47:53 +0100[diff] [blame]132static ssize_t vmcoreinfo_show(struct kobject *kobj,
133 struct kobj_attribute *attr, char *buf)
Ken'ichi Ohmichifd59d232007-10-16 23:27:27 -0700[diff] [blame]134{
Russell Kingdae28012016-08-02 14:06:00 -0700[diff] [blame]135 phys_addr_t vmcore_base = paddr_vmcoreinfo_note();
136 return sprintf(buf, "%pa %x\n", &vmcore_base,
Xunlei Pang203e9e42017-07-12 14:33:14 -0700[diff] [blame]137 (unsigned int)VMCOREINFO_NOTE_SIZE);
Ken'ichi Ohmichifd59d232007-10-16 23:27:27 -0700[diff] [blame]138}
139KERNEL_ATTR_RO(vmcoreinfo);
140
Hari Bathini692f66f2017-05-08 15:56:18 -0700[diff] [blame]141#endif /* CONFIG_CRASH_CORE */
Jeff Moyerc330dda2006-06-23 02:05:07 -0700[diff] [blame]142
Ludwig Nussel088ab0b2011-02-28 15:57:17 +0100[diff] [blame]143/* whether file capabilities are enabled */
144static ssize_t fscaps_show(struct kobject *kobj,
145 struct kobj_attribute *attr, char *buf)
146{
147 return sprintf(buf, "%d\n", file_caps_enabled);
148}
149KERNEL_ATTR_RO(fscaps);
150
Paul E. McKenney79cfea022015-12-07 13:09:52 -0800[diff] [blame]151#ifndef CONFIG_TINY_RCU
Antti P Miettinen3705b882012-10-05 09:59:15 +0300[diff] [blame]152int rcu_expedited;
153static ssize_t rcu_expedited_show(struct kobject *kobj,
154 struct kobj_attribute *attr, char *buf)
155{
Paul E. McKenney5a9be7c2015-11-24 15:44:06 -0800[diff] [blame]156 return sprintf(buf, "%d\n", READ_ONCE(rcu_expedited));
Antti P Miettinen3705b882012-10-05 09:59:15 +0300[diff] [blame]157}
158static ssize_t rcu_expedited_store(struct kobject *kobj,
159 struct kobj_attribute *attr,
160 const char *buf, size_t count)
161{
162 if (kstrtoint(buf, 0, &rcu_expedited))
163 return -EINVAL;
164
165 return count;
166}
167KERNEL_ATTR_RW(rcu_expedited);
168
Paul E. McKenney5a9be7c2015-11-24 15:44:06 -0800[diff] [blame]169int rcu_normal;
170static ssize_t rcu_normal_show(struct kobject *kobj,
171 struct kobj_attribute *attr, char *buf)
172{
173 return sprintf(buf, "%d\n", READ_ONCE(rcu_normal));
174}
175static ssize_t rcu_normal_store(struct kobject *kobj,
176 struct kobj_attribute *attr,
177 const char *buf, size_t count)
178{
179 if (kstrtoint(buf, 0, &rcu_normal))
180 return -EINVAL;
181
182 return count;
183}
184KERNEL_ATTR_RW(rcu_normal);
Paul E. McKenney79cfea022015-12-07 13:09:52 -0800[diff] [blame]185#endif /* #ifndef CONFIG_TINY_RCU */
Paul E. McKenney5a9be7c2015-11-24 15:44:06 -0800[diff] [blame]186
Roland McGrathda1a6792007-07-19 01:48:39 -0700[diff] [blame]187/*
188 * Make /sys/kernel/notes give the raw contents of our kernel .notes section.
189 */
Gideon Israel Dsouza52f5684c2014-04-07 15:39:20 -0700[diff] [blame]190extern const void __start_notes __weak;
191extern const void __stop_notes __weak;
Roland McGrathda1a6792007-07-19 01:48:39 -0700[diff] [blame]192#define notes_size (&__stop_notes - &__start_notes)
193
Chris Wright2c3c8be2010-05-12 18:28:57 -0700[diff] [blame]194static ssize_t notes_read(struct file *filp, struct kobject *kobj,
195 struct bin_attribute *bin_attr,
Roland McGrathda1a6792007-07-19 01:48:39 -0700[diff] [blame]196 char *buf, loff_t off, size_t count)
197{
198 memcpy(buf, &__start_notes + off, count);
199 return count;
200}
201
Bhumika Goyal738bc382017-02-24 15:00:46 -0800[diff] [blame]202static struct bin_attribute notes_attr __ro_after_init = {
Roland McGrathda1a6792007-07-19 01:48:39 -0700[diff] [blame]203 .attr = {
204 .name = "notes",
205 .mode = S_IRUGO,
206 },
207 .read = &notes_read,
208};
209
Greg Kroah-Hartman0ff21e42007-11-06 10:36:58 -0800[diff] [blame]210struct kobject *kernel_kobj;
211EXPORT_SYMBOL_GPL(kernel_kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]212
213static struct attribute * kernel_attrs[] = {
Ludwig Nussel088ab0b2011-02-28 15:57:17 +0100[diff] [blame]214 &fscaps_attr.attr,
Kay Sievers0f76e5a2005-11-11 04:58:04 +0100[diff] [blame]215 &uevent_seqnum_attr.attr,
Michael Marineau86d56132014-04-10 14:09:31 -0700[diff] [blame]216#ifdef CONFIG_UEVENT_HELPER
Kay Sievers0f76e5a2005-11-11 04:58:04 +0100[diff] [blame]217 &uevent_helper_attr.attr,
Michael Marineau86d56132014-04-10 14:09:31 -0700[diff] [blame]218#endif
Dave Hansen22b8ce92008-10-15 22:01:46 -0700[diff] [blame]219#ifdef CONFIG_PROFILING
220 &profiling_attr.attr,
221#endif
Dave Young2965faa2015-09-09 15:38:55 -0700[diff] [blame]222#ifdef CONFIG_KEXEC_CORE
Jeff Moyerc330dda2006-06-23 02:05:07 -0700[diff] [blame]223 &kexec_loaded_attr.attr,
224 &kexec_crash_loaded_attr.attr,
Amerigo Wang06a7f712009-12-15 16:47:46 -0800[diff] [blame]225 &kexec_crash_size_attr.attr,
Hari Bathini692f66f2017-05-08 15:56:18 -0700[diff] [blame]226#endif
227#ifdef CONFIG_CRASH_CORE
Ken'ichi Ohmichifd59d232007-10-16 23:27:27 -0700[diff] [blame]228 &vmcoreinfo_attr.attr,
Jeff Moyerc330dda2006-06-23 02:05:07 -0700[diff] [blame]229#endif
Paul E. McKenney79cfea022015-12-07 13:09:52 -0800[diff] [blame]230#ifndef CONFIG_TINY_RCU
Antti P Miettinen3705b882012-10-05 09:59:15 +0300[diff] [blame]231 &rcu_expedited_attr.attr,
Paul E. McKenney5a9be7c2015-11-24 15:44:06 -0800[diff] [blame]232 &rcu_normal_attr.attr,
Paul E. McKenney79cfea022015-12-07 13:09:52 -0800[diff] [blame]233#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]234 NULL
235};
236
Arvind Yadav9dcdcea2017-07-10 15:51:14 -0700[diff] [blame]237static const struct attribute_group kernel_attr_group = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]238 .attrs = kernel_attrs,
239};
240
241static int __init ksysfs_init(void)
242{
Greg Kroah-Hartmanbd35b932007-10-29 20:13:17 +0100[diff] [blame]243 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]244
Greg Kroah-Hartman0ff21e42007-11-06 10:36:58 -0800[diff] [blame]245 kernel_kobj = kobject_create_and_add("kernel", NULL);
246 if (!kernel_kobj) {
Greg Kroah-Hartmanbd35b932007-10-29 20:13:17 +0100[diff] [blame]247 error = -ENOMEM;
248 goto exit;
249 }
Greg Kroah-Hartman0ff21e42007-11-06 10:36:58 -0800[diff] [blame]250 error = sysfs_create_group(kernel_kobj, &kernel_attr_group);
Greg Kroah-Hartmanbd35b932007-10-29 20:13:17 +0100[diff] [blame]251 if (error)
252 goto kset_exit;
253
254 if (notes_size > 0) {
Roland McGrathda1a6792007-07-19 01:48:39 -0700[diff] [blame]255 notes_attr.size = notes_size;
Greg Kroah-Hartman0ff21e42007-11-06 10:36:58 -0800[diff] [blame]256 error = sysfs_create_bin_file(kernel_kobj, &notes_attr);
Greg Kroah-Hartmanbd35b932007-10-29 20:13:17 +0100[diff] [blame]257 if (error)
258 goto group_exit;
Roland McGrathda1a6792007-07-19 01:48:39 -0700[diff] [blame]259 }
260
Greg Kroah-Hartmanbd35b932007-10-29 20:13:17 +0100[diff] [blame]261 return 0;
262
Greg Kroah-Hartmanbd35b932007-10-29 20:13:17 +0100[diff] [blame]263group_exit:
Greg Kroah-Hartman0ff21e42007-11-06 10:36:58 -0800[diff] [blame]264 sysfs_remove_group(kernel_kobj, &kernel_attr_group);
Greg Kroah-Hartmanbd35b932007-10-29 20:13:17 +0100[diff] [blame]265kset_exit:
Greg Kroah-Hartman78a2d902007-12-20 08:13:05 -0800[diff] [blame]266 kobject_put(kernel_kobj);
Greg Kroah-Hartmanbd35b932007-10-29 20:13:17 +0100[diff] [blame]267exit:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]268 return error;
269}
270
271core_initcall(ksysfs_init);