/* * kernel/ksysfs.c - sysfs attributes in /sys/kernel, which * 		     are not related to any other subsystem * * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org> *  * This file is release under the GPLv2 * */ #include <linux/kobject.h>#include <linux/string.h>#include <linux/sysfs.h>#include <linux/export.h>#include <linux/init.h>#include <linux/kexec.h>#include <linux/profile.h>#include <linux/stat.h>#include <linux/sched.h>#include <linux/capability.h> #define KERNEL_ATTR_RO(_name) \static struct kobj_attribute _name##_attr = __ATTR_RO(_name) #define KERNEL_ATTR_RW(_name) \static struct kobj_attribute _name##_attr = \	__ATTR(_name, 0644, _name##_show, _name##_store) /* current uevent sequence number */static ssize_t uevent_seqnum_show(struct kobject *kobj,				  struct kobj_attribute *attr, char *buf){	return sprintf(buf, "%llu\n", (unsigned long long)uevent_seqnum);}KERNEL_ATTR_RO(uevent_seqnum); /* uevent helper program, used during early boot */static ssize_t uevent_helper_show(struct kobject *kobj,				  struct kobj_attribute *attr, char *buf){	return sprintf(buf, "%s\n", uevent_helper);}static ssize_t uevent_helper_store(struct kobject *kobj,				   struct kobj_attribute *attr,				   const char *buf, size_t count){	if (count+1 > UEVENT_HELPER_PATH_LEN)		return -ENOENT;	memcpy(uevent_helper, buf, count);	uevent_helper[count] = '\0';	if (count && uevent_helper[count-1] == '\n')		uevent_helper[count-1] = '\0';	return count;}KERNEL_ATTR_RW(uevent_helper);  #ifdef CONFIG_PROFILINGstatic ssize_t profiling_show(struct kobject *kobj,				  struct kobj_attribute *attr, char *buf){	return sprintf(buf, "%d\n", prof_on);}static ssize_t profiling_store(struct kobject *kobj,				   struct kobj_attribute *attr,				   const char *buf, size_t count){	int ret; 	if (prof_on)		return -EEXIST;	/*	 * This eventually calls into get_option() which	 * has a ton of callers and is not const.  It is	 * easiest to cast it away here.	 */	profile_setup((char *)buf);	ret = profile_init();	if (ret)		return ret;	ret = create_proc_profile();	if (ret)		return ret;	return count;}KERNEL_ATTR_RW(profiling);#endif #ifdef CONFIG_KEXECstatic ssize_t kexec_loaded_show(struct kobject *kobj,				 struct kobj_attribute *attr, char *buf){	return sprintf(buf, "%d\n", !!kexec_image);}KERNEL_ATTR_RO(kexec_loaded); static ssize_t kexec_crash_loaded_show(struct kobject *kobj,				       struct kobj_attribute *attr, char *buf){	return sprintf(buf, "%d\n", !!kexec_crash_image);}KERNEL_ATTR_RO(kexec_crash_loaded); static ssize_t kexec_crash_size_show(struct kobject *kobj,				       struct kobj_attribute *attr, char *buf){	return sprintf(buf, "%zu\n", crash_get_memory_size());}static ssize_t kexec_crash_size_store(struct kobject *kobj,				   struct kobj_attribute *attr,				   const char *buf, size_t count){	unsigned long cnt;	int ret; 	if (kstrtoul(buf, 0, &cnt))		return -EINVAL; 	ret = crash_shrink_memory(cnt);	return ret < 0 ? ret : count;}KERNEL_ATTR_RW(kexec_crash_size); static ssize_t vmcoreinfo_show(struct kobject *kobj,			       struct kobj_attribute *attr, char *buf){	return sprintf(buf, "%lx %x\n",		       paddr_vmcoreinfo_note(),		       (unsigned int)vmcoreinfo_max_size);}KERNEL_ATTR_RO(vmcoreinfo); #endif /* CONFIG_KEXEC */ /* whether file capabilities are enabled */static ssize_t fscaps_show(struct kobject *kobj,				  struct kobj_attribute *attr, char *buf){	return sprintf(buf, "%d\n", file_caps_enabled);}KERNEL_ATTR_RO(fscaps); int rcu_expedited;static ssize_t rcu_expedited_show(struct kobject *kobj,				  struct kobj_attribute *attr, char *buf){	return sprintf(buf, "%d\n", rcu_expedited);}static ssize_t rcu_expedited_store(struct kobject *kobj,				   struct kobj_attribute *attr,				   const char *buf, size_t count){	if (kstrtoint(buf, 0, &rcu_expedited))		return -EINVAL; 	return count;}KERNEL_ATTR_RW(rcu_expedited); /* * Make /sys/kernel/notes give the raw contents of our kernel .notes section. */extern const void __start_notes __attribute__((weak));extern const void __stop_notes __attribute__((weak));#define	notes_size (&__stop_notes - &__start_notes) static ssize_t notes_read(struct file *filp, struct kobject *kobj,			  struct bin_attribute *bin_attr,			  char *buf, loff_t off, size_t count){	memcpy(buf, &__start_notes + off, count);	return count;} static struct bin_attribute notes_attr = {	.attr = {		.name = "notes",		.mode = S_IRUGO,	},	.read = &notes_read,}; struct kobject *kernel_kobj;EXPORT_SYMBOL_GPL(kernel_kobj); static struct attribute * kernel_attrs[] = {	&fscaps_attr.attr,	&uevent_seqnum_attr.attr,	&uevent_helper_attr.attr,#ifdef CONFIG_PROFILING	&profiling_attr.attr,#endif#ifdef CONFIG_KEXEC	&kexec_loaded_attr.attr,	&kexec_crash_loaded_attr.attr,	&kexec_crash_size_attr.attr,	&vmcoreinfo_attr.attr,#endif	&rcu_expedited_attr.attr,	NULL}; static struct attribute_group kernel_attr_group = {	.attrs = kernel_attrs,}; static int __init ksysfs_init(void){	int error; 	kernel_kobj = kobject_create_and_add("kernel", NULL);	if (!kernel_kobj) {		error = -ENOMEM;		goto exit;	}	error = sysfs_create_group(kernel_kobj, &kernel_attr_group);	if (error)		goto kset_exit; 	if (notes_size > 0) {		notes_attr.size = notes_size;		error = sysfs_create_bin_file(kernel_kobj, &notes_attr);		if (error)			goto group_exit;	} 	return 0; group_exit:	sysfs_remove_group(kernel_kobj, &kernel_attr_group);kset_exit:	kobject_put(kernel_kobj);exit:	return error;} core_initcall(ksysfs_init);