blob: 528dd78e7e7e94595106d70c6eefb35d3a5b89aa [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>
14#include <linux/module.h>
15#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>
Dhaval Giani5cb350b2007-10-15 17:00:14 +020018#include <linux/sched.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019
20#define KERNEL_ATTR_RO(_name) \
Kay Sievers386f2752007-11-02 13:47:53 +010021static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
Linus Torvalds1da177e2005-04-16 15:20:36 -070022
23#define KERNEL_ATTR_RW(_name) \
Kay Sievers386f2752007-11-02 13:47:53 +010024static struct kobj_attribute _name##_attr = \
Linus Torvalds1da177e2005-04-16 15:20:36 -070025 __ATTR(_name, 0644, _name##_show, _name##_store)
26
Ming Leicd3772e2008-11-16 18:22:09 +080027#if defined(CONFIG_HOTPLUG)
Kay Sievers0f76e5a2005-11-11 04:58:04 +010028/* current uevent sequence number */
Kay Sievers386f2752007-11-02 13:47:53 +010029static ssize_t uevent_seqnum_show(struct kobject *kobj,
30 struct kobj_attribute *attr, char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -070031{
Kay Sievers386f2752007-11-02 13:47:53 +010032 return sprintf(buf, "%llu\n", (unsigned long long)uevent_seqnum);
Linus Torvalds1da177e2005-04-16 15:20:36 -070033}
Kay Sievers0f76e5a2005-11-11 04:58:04 +010034KERNEL_ATTR_RO(uevent_seqnum);
35
36/* uevent helper program, used during early boo */
Kay Sievers386f2752007-11-02 13:47:53 +010037static ssize_t uevent_helper_show(struct kobject *kobj,
38 struct kobj_attribute *attr, char *buf)
Kay Sievers0f76e5a2005-11-11 04:58:04 +010039{
Kay Sievers386f2752007-11-02 13:47:53 +010040 return sprintf(buf, "%s\n", uevent_helper);
Kay Sievers0f76e5a2005-11-11 04:58:04 +010041}
Kay Sievers386f2752007-11-02 13:47:53 +010042static ssize_t uevent_helper_store(struct kobject *kobj,
43 struct kobj_attribute *attr,
44 const char *buf, size_t count)
Kay Sievers0f76e5a2005-11-11 04:58:04 +010045{
Kay Sievers312c0042005-11-16 09:00:00 +010046 if (count+1 > UEVENT_HELPER_PATH_LEN)
Kay Sievers0f76e5a2005-11-11 04:58:04 +010047 return -ENOENT;
Kay Sievers386f2752007-11-02 13:47:53 +010048 memcpy(uevent_helper, buf, count);
Kay Sievers312c0042005-11-16 09:00:00 +010049 uevent_helper[count] = '\0';
50 if (count && uevent_helper[count-1] == '\n')
51 uevent_helper[count-1] = '\0';
Kay Sievers0f76e5a2005-11-11 04:58:04 +010052 return count;
53}
54KERNEL_ATTR_RW(uevent_helper);
Linus Torvalds1da177e2005-04-16 15:20:36 -070055#endif
56
Dave Hansen22b8ce92008-10-15 22:01:46 -070057#ifdef CONFIG_PROFILING
58static ssize_t profiling_show(struct kobject *kobj,
59 struct kobj_attribute *attr, char *buf)
60{
61 return sprintf(buf, "%d\n", prof_on);
62}
63static ssize_t profiling_store(struct kobject *kobj,
64 struct kobj_attribute *attr,
65 const char *buf, size_t count)
66{
67 int ret;
68
69 if (prof_on)
70 return -EEXIST;
71 /*
72 * This eventually calls into get_option() which
73 * has a ton of callers and is not const. It is
74 * easiest to cast it away here.
75 */
76 profile_setup((char *)buf);
77 ret = profile_init();
78 if (ret)
79 return ret;
80 ret = create_proc_profile();
81 if (ret)
82 return ret;
83 return count;
84}
85KERNEL_ATTR_RW(profiling);
86#endif
87
Jeff Moyerc330dda2006-06-23 02:05:07 -070088#ifdef CONFIG_KEXEC
Kay Sievers386f2752007-11-02 13:47:53 +010089static ssize_t kexec_loaded_show(struct kobject *kobj,
90 struct kobj_attribute *attr, char *buf)
Jeff Moyerc330dda2006-06-23 02:05:07 -070091{
Kay Sievers386f2752007-11-02 13:47:53 +010092 return sprintf(buf, "%d\n", !!kexec_image);
Jeff Moyerc330dda2006-06-23 02:05:07 -070093}
94KERNEL_ATTR_RO(kexec_loaded);
95
Kay Sievers386f2752007-11-02 13:47:53 +010096static ssize_t kexec_crash_loaded_show(struct kobject *kobj,
97 struct kobj_attribute *attr, char *buf)
Jeff Moyerc330dda2006-06-23 02:05:07 -070098{
Kay Sievers386f2752007-11-02 13:47:53 +010099 return sprintf(buf, "%d\n", !!kexec_crash_image);
Jeff Moyerc330dda2006-06-23 02:05:07 -0700100}
101KERNEL_ATTR_RO(kexec_crash_loaded);
Ken'ichi Ohmichifd59d232007-10-16 23:27:27 -0700102
Kay Sievers386f2752007-11-02 13:47:53 +0100103static ssize_t vmcoreinfo_show(struct kobject *kobj,
104 struct kobj_attribute *attr, char *buf)
Ken'ichi Ohmichifd59d232007-10-16 23:27:27 -0700105{
Kay Sievers386f2752007-11-02 13:47:53 +0100106 return sprintf(buf, "%lx %x\n",
Ken'ichi Ohmichifd59d232007-10-16 23:27:27 -0700107 paddr_vmcoreinfo_note(),
Ken'ichi Ohmichid7682812007-10-16 23:27:28 -0700108 (unsigned int)vmcoreinfo_max_size);
Ken'ichi Ohmichifd59d232007-10-16 23:27:27 -0700109}
110KERNEL_ATTR_RO(vmcoreinfo);
111
Jeff Moyerc330dda2006-06-23 02:05:07 -0700112#endif /* CONFIG_KEXEC */
113
Roland McGrathda1a6792007-07-19 01:48:39 -0700114/*
115 * Make /sys/kernel/notes give the raw contents of our kernel .notes section.
116 */
David Howells0b1937a2007-07-20 17:02:04 +0100117extern const void __start_notes __attribute__((weak));
118extern const void __stop_notes __attribute__((weak));
Roland McGrathda1a6792007-07-19 01:48:39 -0700119#define notes_size (&__stop_notes - &__start_notes)
120
121static ssize_t notes_read(struct kobject *kobj, struct bin_attribute *bin_attr,
122 char *buf, loff_t off, size_t count)
123{
124 memcpy(buf, &__start_notes + off, count);
125 return count;
126}
127
128static struct bin_attribute notes_attr = {
129 .attr = {
130 .name = "notes",
131 .mode = S_IRUGO,
132 },
133 .read = &notes_read,
134};
135
Greg Kroah-Hartman0ff21e42007-11-06 10:36:58 -0800136struct kobject *kernel_kobj;
137EXPORT_SYMBOL_GPL(kernel_kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138
139static struct attribute * kernel_attrs[] = {
Ming Leicd3772e2008-11-16 18:22:09 +0800140#if defined(CONFIG_HOTPLUG)
Kay Sievers0f76e5a2005-11-11 04:58:04 +0100141 &uevent_seqnum_attr.attr,
142 &uevent_helper_attr.attr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143#endif
Dave Hansen22b8ce92008-10-15 22:01:46 -0700144#ifdef CONFIG_PROFILING
145 &profiling_attr.attr,
146#endif
Jeff Moyerc330dda2006-06-23 02:05:07 -0700147#ifdef CONFIG_KEXEC
148 &kexec_loaded_attr.attr,
149 &kexec_crash_loaded_attr.attr,
Ken'ichi Ohmichifd59d232007-10-16 23:27:27 -0700150 &vmcoreinfo_attr.attr,
Jeff Moyerc330dda2006-06-23 02:05:07 -0700151#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 NULL
153};
154
155static struct attribute_group kernel_attr_group = {
156 .attrs = kernel_attrs,
157};
158
159static int __init ksysfs_init(void)
160{
Greg Kroah-Hartmanbd35b932007-10-29 20:13:17 +0100161 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162
Greg Kroah-Hartman0ff21e42007-11-06 10:36:58 -0800163 kernel_kobj = kobject_create_and_add("kernel", NULL);
164 if (!kernel_kobj) {
Greg Kroah-Hartmanbd35b932007-10-29 20:13:17 +0100165 error = -ENOMEM;
166 goto exit;
167 }
Greg Kroah-Hartman0ff21e42007-11-06 10:36:58 -0800168 error = sysfs_create_group(kernel_kobj, &kernel_attr_group);
Greg Kroah-Hartmanbd35b932007-10-29 20:13:17 +0100169 if (error)
170 goto kset_exit;
171
172 if (notes_size > 0) {
Roland McGrathda1a6792007-07-19 01:48:39 -0700173 notes_attr.size = notes_size;
Greg Kroah-Hartman0ff21e42007-11-06 10:36:58 -0800174 error = sysfs_create_bin_file(kernel_kobj, &notes_attr);
Greg Kroah-Hartmanbd35b932007-10-29 20:13:17 +0100175 if (error)
176 goto group_exit;
Roland McGrathda1a6792007-07-19 01:48:39 -0700177 }
178
Kay Sieverseb41d942007-11-02 13:47:53 +0100179 /* create the /sys/kernel/uids/ directory */
180 error = uids_sysfs_init();
Greg Kroah-Hartmanbd35b932007-10-29 20:13:17 +0100181 if (error)
182 goto notes_exit;
Dhaval Giani5cb350b2007-10-15 17:00:14 +0200183
Greg Kroah-Hartmanbd35b932007-10-29 20:13:17 +0100184 return 0;
185
186notes_exit:
187 if (notes_size > 0)
Greg Kroah-Hartman0ff21e42007-11-06 10:36:58 -0800188 sysfs_remove_bin_file(kernel_kobj, &notes_attr);
Greg Kroah-Hartmanbd35b932007-10-29 20:13:17 +0100189group_exit:
Greg Kroah-Hartman0ff21e42007-11-06 10:36:58 -0800190 sysfs_remove_group(kernel_kobj, &kernel_attr_group);
Greg Kroah-Hartmanbd35b932007-10-29 20:13:17 +0100191kset_exit:
Greg Kroah-Hartman78a2d902007-12-20 08:13:05 -0800192 kobject_put(kernel_kobj);
Greg Kroah-Hartmanbd35b932007-10-29 20:13:17 +0100193exit:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 return error;
195}
196
197core_initcall(ksysfs_init);