blob: 6683ccef9fffb2de28b6a4d6d01393b080811d6a [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070011#include <linux/kobject.h>
12#include <linux/string.h>
13#include <linux/sysfs.h>
Paul Gortmaker9984de12011-05-23 14:51:41 -040014#include <linux/export.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/init.h>
Jeff Moyerc330dda2006-06-23 02:05:07 -070016#include <linux/kexec.h>
Dave Hansen22b8ce92008-10-15 22:01:46 -070017#include <linux/profile.h>
Paul Gortmaker15964252011-07-28 14:22:29 -040018#include <linux/stat.h>
Dhaval Giani5cb350b2007-10-15 17:00:14 +020019#include <linux/sched.h>
Ludwig Nussel088ab0b2011-02-28 15:57:17 +010020#include <linux/capability.h>
Gideon Israel Dsouza52f5684c2014-04-07 15:39:20 -070021#include <linux/compiler.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022
Paul Gortmaker7a754742014-02-11 16:10:12 -050023#include <linux/rcupdate.h> /* rcu_expedited */
24
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#define KERNEL_ATTR_RO(_name) \
Kay Sievers386f2752007-11-02 13:47:53 +010026static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
Linus Torvalds1da177e2005-04-16 15:20:36 -070027
28#define KERNEL_ATTR_RW(_name) \
Kay Sievers386f2752007-11-02 13:47:53 +010029static struct kobj_attribute _name##_attr = \
Linus Torvalds1da177e2005-04-16 15:20:36 -070030 __ATTR(_name, 0644, _name##_show, _name##_store)
31
Kay Sievers0f76e5a2005-11-11 04:58:04 +010032/* current uevent sequence number */
Kay Sievers386f2752007-11-02 13:47:53 +010033static ssize_t uevent_seqnum_show(struct kobject *kobj,
34 struct kobj_attribute *attr, char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -070035{
Kay Sievers386f2752007-11-02 13:47:53 +010036 return sprintf(buf, "%llu\n", (unsigned long long)uevent_seqnum);
Linus Torvalds1da177e2005-04-16 15:20:36 -070037}
Kay Sievers0f76e5a2005-11-11 04:58:04 +010038KERNEL_ATTR_RO(uevent_seqnum);
39
Michael Marineau86d56132014-04-10 14:09:31 -070040#ifdef CONFIG_UEVENT_HELPER
Thadeu Lima de Souza Cascardoaf665852010-01-17 19:14:26 -020041/* uevent helper program, used during early boot */
Kay Sievers386f2752007-11-02 13:47:53 +010042static ssize_t uevent_helper_show(struct kobject *kobj,
43 struct kobj_attribute *attr, char *buf)
Kay Sievers0f76e5a2005-11-11 04:58:04 +010044{
Kay Sievers386f2752007-11-02 13:47:53 +010045 return sprintf(buf, "%s\n", uevent_helper);
Kay Sievers0f76e5a2005-11-11 04:58:04 +010046}
Kay Sievers386f2752007-11-02 13:47:53 +010047static 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 +010050{
Kay Sievers312c0042005-11-16 09:00:00 +010051 if (count+1 > UEVENT_HELPER_PATH_LEN)
Kay Sievers0f76e5a2005-11-11 04:58:04 +010052 return -ENOENT;
Kay Sievers386f2752007-11-02 13:47:53 +010053 memcpy(uevent_helper, buf, count);
Kay Sievers312c0042005-11-16 09:00:00 +010054 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 +010057 return count;
58}
59KERNEL_ATTR_RW(uevent_helper);
Michael Marineau86d56132014-04-10 14:09:31 -070060#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070061
Dave Hansen22b8ce92008-10-15 22:01:46 -070062#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
Jeff Moyerc330dda2006-06-23 02:05:07 -070093#ifdef CONFIG_KEXEC
Kay Sievers386f2752007-11-02 13:47:53 +010094static ssize_t kexec_loaded_show(struct kobject *kobj,
95 struct kobj_attribute *attr, char *buf)
Jeff Moyerc330dda2006-06-23 02:05:07 -070096{
Kay Sievers386f2752007-11-02 13:47:53 +010097 return sprintf(buf, "%d\n", !!kexec_image);
Jeff Moyerc330dda2006-06-23 02:05:07 -070098}
99KERNEL_ATTR_RO(kexec_loaded);
100
Kay Sievers386f2752007-11-02 13:47:53 +0100101static ssize_t kexec_crash_loaded_show(struct kobject *kobj,
102 struct kobj_attribute *attr, char *buf)
Jeff Moyerc330dda2006-06-23 02:05:07 -0700103{
Kay Sievers386f2752007-11-02 13:47:53 +0100104 return sprintf(buf, "%d\n", !!kexec_crash_image);
Jeff Moyerc330dda2006-06-23 02:05:07 -0700105}
106KERNEL_ATTR_RO(kexec_crash_loaded);
Ken'ichi Ohmichifd59d232007-10-16 23:27:27 -0700107
Amerigo Wang06a7f712009-12-15 16:47:46 -0800108static 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 -0700120 if (kstrtoul(buf, 0, &cnt))
Amerigo Wang06a7f712009-12-15 16:47:46 -0800121 return -EINVAL;
122
123 ret = crash_shrink_memory(cnt);
124 return ret < 0 ? ret : count;
125}
126KERNEL_ATTR_RW(kexec_crash_size);
127
Kay Sievers386f2752007-11-02 13:47:53 +0100128static ssize_t vmcoreinfo_show(struct kobject *kobj,
129 struct kobj_attribute *attr, char *buf)
Ken'ichi Ohmichifd59d232007-10-16 23:27:27 -0700130{
Kay Sievers386f2752007-11-02 13:47:53 +0100131 return sprintf(buf, "%lx %x\n",
Ken'ichi Ohmichifd59d232007-10-16 23:27:27 -0700132 paddr_vmcoreinfo_note(),
Vivek Goyal77019962014-01-23 15:56:00 -0800133 (unsigned int)sizeof(vmcoreinfo_note));
Ken'ichi Ohmichifd59d232007-10-16 23:27:27 -0700134}
135KERNEL_ATTR_RO(vmcoreinfo);
136
Jeff Moyerc330dda2006-06-23 02:05:07 -0700137#endif /* CONFIG_KEXEC */
138
Ludwig Nussel088ab0b2011-02-28 15:57:17 +0100139/* 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
Antti P Miettinen3705b882012-10-05 09:59:15 +0300147int rcu_expedited;
148static ssize_t rcu_expedited_show(struct kobject *kobj,
149 struct kobj_attribute *attr, char *buf)
150{
151 return sprintf(buf, "%d\n", rcu_expedited);
152}
153static ssize_t rcu_expedited_store(struct kobject *kobj,
154 struct kobj_attribute *attr,
155 const char *buf, size_t count)
156{
157 if (kstrtoint(buf, 0, &rcu_expedited))
158 return -EINVAL;
159
160 return count;
161}
162KERNEL_ATTR_RW(rcu_expedited);
163
Roland McGrathda1a6792007-07-19 01:48:39 -0700164/*
165 * Make /sys/kernel/notes give the raw contents of our kernel .notes section.
166 */
Gideon Israel Dsouza52f5684c2014-04-07 15:39:20 -0700167extern const void __start_notes __weak;
168extern const void __stop_notes __weak;
Roland McGrathda1a6792007-07-19 01:48:39 -0700169#define notes_size (&__stop_notes - &__start_notes)
170
Chris Wright2c3c8be2010-05-12 18:28:57 -0700171static ssize_t notes_read(struct file *filp, struct kobject *kobj,
172 struct bin_attribute *bin_attr,
Roland McGrathda1a6792007-07-19 01:48:39 -0700173 char *buf, loff_t off, size_t count)
174{
175 memcpy(buf, &__start_notes + off, count);
176 return count;
177}
178
179static struct bin_attribute notes_attr = {
180 .attr = {
181 .name = "notes",
182 .mode = S_IRUGO,
183 },
184 .read = &notes_read,
185};
186
Greg Kroah-Hartman0ff21e42007-11-06 10:36:58 -0800187struct kobject *kernel_kobj;
188EXPORT_SYMBOL_GPL(kernel_kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189
190static struct attribute * kernel_attrs[] = {
Ludwig Nussel088ab0b2011-02-28 15:57:17 +0100191 &fscaps_attr.attr,
Kay Sievers0f76e5a2005-11-11 04:58:04 +0100192 &uevent_seqnum_attr.attr,
Michael Marineau86d56132014-04-10 14:09:31 -0700193#ifdef CONFIG_UEVENT_HELPER
Kay Sievers0f76e5a2005-11-11 04:58:04 +0100194 &uevent_helper_attr.attr,
Michael Marineau86d56132014-04-10 14:09:31 -0700195#endif
Dave Hansen22b8ce92008-10-15 22:01:46 -0700196#ifdef CONFIG_PROFILING
197 &profiling_attr.attr,
198#endif
Jeff Moyerc330dda2006-06-23 02:05:07 -0700199#ifdef CONFIG_KEXEC
200 &kexec_loaded_attr.attr,
201 &kexec_crash_loaded_attr.attr,
Amerigo Wang06a7f712009-12-15 16:47:46 -0800202 &kexec_crash_size_attr.attr,
Ken'ichi Ohmichifd59d232007-10-16 23:27:27 -0700203 &vmcoreinfo_attr.attr,
Jeff Moyerc330dda2006-06-23 02:05:07 -0700204#endif
Antti P Miettinen3705b882012-10-05 09:59:15 +0300205 &rcu_expedited_attr.attr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 NULL
207};
208
209static struct attribute_group kernel_attr_group = {
210 .attrs = kernel_attrs,
211};
212
213static int __init ksysfs_init(void)
214{
Greg Kroah-Hartmanbd35b932007-10-29 20:13:17 +0100215 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216
Greg Kroah-Hartman0ff21e42007-11-06 10:36:58 -0800217 kernel_kobj = kobject_create_and_add("kernel", NULL);
218 if (!kernel_kobj) {
Greg Kroah-Hartmanbd35b932007-10-29 20:13:17 +0100219 error = -ENOMEM;
220 goto exit;
221 }
Greg Kroah-Hartman0ff21e42007-11-06 10:36:58 -0800222 error = sysfs_create_group(kernel_kobj, &kernel_attr_group);
Greg Kroah-Hartmanbd35b932007-10-29 20:13:17 +0100223 if (error)
224 goto kset_exit;
225
226 if (notes_size > 0) {
Roland McGrathda1a6792007-07-19 01:48:39 -0700227 notes_attr.size = notes_size;
Greg Kroah-Hartman0ff21e42007-11-06 10:36:58 -0800228 error = sysfs_create_bin_file(kernel_kobj, &notes_attr);
Greg Kroah-Hartmanbd35b932007-10-29 20:13:17 +0100229 if (error)
230 goto group_exit;
Roland McGrathda1a6792007-07-19 01:48:39 -0700231 }
232
Greg Kroah-Hartmanbd35b932007-10-29 20:13:17 +0100233 return 0;
234
Greg Kroah-Hartmanbd35b932007-10-29 20:13:17 +0100235group_exit:
Greg Kroah-Hartman0ff21e42007-11-06 10:36:58 -0800236 sysfs_remove_group(kernel_kobj, &kernel_attr_group);
Greg Kroah-Hartmanbd35b932007-10-29 20:13:17 +0100237kset_exit:
Greg Kroah-Hartman78a2d902007-12-20 08:13:05 -0800238 kobject_put(kernel_kobj);
Greg Kroah-Hartmanbd35b932007-10-29 20:13:17 +0100239exit:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 return error;
241}
242
243core_initcall(ksysfs_init);