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/* * kobject.c - library routines for handling generic kernel objects * * Copyright (c) 2002-2003 Patrick Mochel <mochel@osdl.org> * Copyright (c) 2006-2007 Greg Kroah-Hartman <greg@kroah.com> * Copyright (c) 2006-2007 Novell Inc. * * This file is released under the GPLv2. * * * Please see the file Documentation/kobject.txt for critical information * about using the kobject interface. */ #include <linux/kobject.h>#include <linux/string.h>#include <linux/export.h>#include <linux/stat.h>#include <linux/slab.h>#include <linux/random.h> /** * kobject_namespace - return @kobj's namespace tag * @kobj: kobject in question * * Returns namespace tag of @kobj if its parent has namespace ops enabled * and thus @kobj should have a namespace tag associated with it.  Returns * %NULL otherwise. */const void *kobject_namespace(struct kobject *kobj){	const struct kobj_ns_type_operations *ns_ops = kobj_ns_ops(kobj); 	if (!ns_ops || ns_ops->type == KOBJ_NS_TYPE_NONE)		return NULL; 	return kobj->ktype->namespace(kobj);} /* * populate_dir - populate directory with attributes. * @kobj: object we're working on. * * Most subsystems have a set of default attributes that are associated * with an object that registers with them.  This is a helper called during * object registration that loops through the default attributes of the * subsystem and creates attributes files for them in sysfs. */static int populate_dir(struct kobject *kobj){	struct kobj_type *t = get_ktype(kobj);	struct attribute *attr;	int error = 0;	int i; 	if (t && t->default_attrs) {		for (i = 0; (attr = t->default_attrs[i]) != NULL; i++) {			error = sysfs_create_file(kobj, attr);			if (error)				break;		}	}	return error;} static int create_dir(struct kobject *kobj){	const struct kobj_ns_type_operations *ops;	int error; 	error = sysfs_create_dir_ns(kobj, kobject_namespace(kobj));	if (error)		return error; 	error = populate_dir(kobj);	if (error) {		sysfs_remove_dir(kobj);		return error;	} 	/*	 * @kobj->sd may be deleted by an ancestor going away.  Hold an	 * extra reference so that it stays until @kobj is gone.	 */	sysfs_get(kobj->sd); 	/*	 * If @kobj has ns_ops, its children need to be filtered based on	 * their namespace tags.  Enable namespace support on @kobj->sd.	 */	ops = kobj_child_ns_ops(kobj);	if (ops) {		BUG_ON(ops->type <= KOBJ_NS_TYPE_NONE);		BUG_ON(ops->type >= KOBJ_NS_TYPES);		BUG_ON(!kobj_ns_type_registered(ops->type)); 		sysfs_enable_ns(kobj->sd);	} 	return 0;} static int get_kobj_path_length(struct kobject *kobj){	int length = 1;	struct kobject *parent = kobj; 	/* walk up the ancestors until we hit the one pointing to the	 * root.	 * Add 1 to strlen for leading '/' of each level.	 */	do {		if (kobject_name(parent) == NULL)			return 0;		length += strlen(kobject_name(parent)) + 1;		parent = parent->parent;	} while (parent);	return length;} static void fill_kobj_path(struct kobject *kobj, char *path, int length){	struct kobject *parent; 	--length;	for (parent = kobj; parent; parent = parent->parent) {		int cur = strlen(kobject_name(parent));		/* back up enough to print this name with '/' */		length -= cur;		strncpy(path + length, kobject_name(parent), cur);		*(path + --length) = '/';	} 	pr_debug("kobject: '%s' (%p): %s: path = '%s'\n", kobject_name(kobj),		 kobj, __func__, path);} /** * kobject_get_path - generate and return the path associated with a given kobj and kset pair. * * @kobj:	kobject in question, with which to build the path * @gfp_mask:	the allocation type used to allocate the path * * The result must be freed by the caller with kfree(). */char *kobject_get_path(struct kobject *kobj, gfp_t gfp_mask){	char *path;	int len; 	len = get_kobj_path_length(kobj);	if (len == 0)		return NULL;	path = kzalloc(len, gfp_mask);	if (!path)		return NULL;	fill_kobj_path(kobj, path, len); 	return path;}EXPORT_SYMBOL_GPL(kobject_get_path); /* add the kobject to its kset's list */static void kobj_kset_join(struct kobject *kobj){	if (!kobj->kset)		return; 	kset_get(kobj->kset);	spin_lock(&kobj->kset->list_lock);	list_add_tail(&kobj->entry, &kobj->kset->list);	spin_unlock(&kobj->kset->list_lock);} /* remove the kobject from its kset's list */static void kobj_kset_leave(struct kobject *kobj){	if (!kobj->kset)		return; 	spin_lock(&kobj->kset->list_lock);	list_del_init(&kobj->entry);	spin_unlock(&kobj->kset->list_lock);	kset_put(kobj->kset);} static void kobject_init_internal(struct kobject *kobj){	if (!kobj)		return;	kref_init(&kobj->kref);	INIT_LIST_HEAD(&kobj->entry);	kobj->state_in_sysfs = 0;	kobj->state_add_uevent_sent = 0;	kobj->state_remove_uevent_sent = 0;	kobj->state_initialized = 1;}  static int kobject_add_internal(struct kobject *kobj){	int error = 0;	struct kobject *parent; 	if (!kobj)		return -ENOENT; 	if (!kobj->name || !kobj->name[0]) {		WARN(1, "kobject: (%p): attempted to be registered with empty "			 "name!\n", kobj);		return -EINVAL;	} 	parent = kobject_get(kobj->parent); 	/* join kset if set, use it as parent if we do not already have one */	if (kobj->kset) {		if (!parent)			parent = kobject_get(&kobj->kset->kobj);		kobj_kset_join(kobj);		kobj->parent = parent;	} 	pr_debug("kobject: '%s' (%p): %s: parent: '%s', set: '%s'\n",		 kobject_name(kobj), kobj, __func__,		 parent ? kobject_name(parent) : "<NULL>",		 kobj->kset ? kobject_name(&kobj->kset->kobj) : "<NULL>"); 	error = create_dir(kobj);	if (error) {		kobj_kset_leave(kobj);		kobject_put(parent);		kobj->parent = NULL; 		/* be noisy on error issues */		if (error == -EEXIST)			WARN(1, "%s failed for %s with "			     "-EEXIST, don't try to register things with "			     "the same name in the same directory.\n",			     __func__, kobject_name(kobj));		else			WARN(1, "%s failed for %s (error: %d parent: %s)\n",			     __func__, kobject_name(kobj), error,			     parent ? kobject_name(parent) : "'none'");	} else		kobj->state_in_sysfs = 1; 	return error;} /** * kobject_set_name_vargs - Set the name of an kobject * @kobj: struct kobject to set the name of * @fmt: format string used to build the name * @vargs: vargs to format the string. */int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,				  va_list vargs){	const char *s; 	if (kobj->name && !fmt)		return 0; 	s = kvasprintf_const(GFP_KERNEL, fmt, vargs);	if (!s)		return -ENOMEM; 	/*	 * ewww... some of these buggers have '/' in the name ... If	 * that's the case, we need to make sure we have an actual	 * allocated copy to modify, since kvasprintf_const may have	 * returned something from .rodata.	 */	if (strchr(s, '/')) {		char *t; 		t = kstrdup(s, GFP_KERNEL);		kfree_const(s);		if (!t)			return -ENOMEM;		strreplace(t, '/', '!');		s = t;	}	kfree_const(kobj->name);	kobj->name = s; 	return 0;} /** * kobject_set_name - Set the name of a kobject * @kobj: struct kobject to set the name of * @fmt: format string used to build the name * * This sets the name of the kobject.  If you have already added the * kobject to the system, you must call kobject_rename() in order to * change the name of the kobject. */int kobject_set_name(struct kobject *kobj, const char *fmt, ...){	va_list vargs;	int retval; 	va_start(vargs, fmt);	retval = kobject_set_name_vargs(kobj, fmt, vargs);	va_end(vargs); 	return retval;}EXPORT_SYMBOL(kobject_set_name); /** * kobject_init - initialize a kobject structure * @kobj: pointer to the kobject to initialize * @ktype: pointer to the ktype for this kobject. * * This function will properly initialize a kobject such that it can then * be passed to the kobject_add() call. * * After this function is called, the kobject MUST be cleaned up by a call * to kobject_put(), not by a call to kfree directly to ensure that all of * the memory is cleaned up properly. */void kobject_init(struct kobject *kobj, struct kobj_type *ktype){	char *err_str; 	if (!kobj) {		err_str = "invalid kobject pointer!";		goto error;	}	if (!ktype) {		err_str = "must have a ktype to be initialized properly!\n";		goto error;	}	if (kobj->state_initialized) {		/* do not error out as sometimes we can recover */		printk(KERN_ERR "kobject (%p): tried to init an initialized "		       "object, something is seriously wrong.\n", kobj);		dump_stack();	} 	kobject_init_internal(kobj);	kobj->ktype = ktype;	return; error:	printk(KERN_ERR "kobject (%p): %s\n", kobj, err_str);	dump_stack();}EXPORT_SYMBOL(kobject_init); static __printf(3, 0) int kobject_add_varg(struct kobject *kobj,					   struct kobject *parent,					   const char *fmt, va_list vargs){	int retval; 	retval = kobject_set_name_vargs(kobj, fmt, vargs);	if (retval) {		printk(KERN_ERR "kobject: can not set name properly!\n");		return retval;	}	kobj->parent = parent;	return kobject_add_internal(kobj);} /** * kobject_add - the main kobject add function * @kobj: the kobject to add * @parent: pointer to the parent of the kobject. * @fmt: format to name the kobject with. * * The kobject name is set and added to the kobject hierarchy in this * function. * * If @parent is set, then the parent of the @kobj will be set to it. * If @parent is NULL, then the parent of the @kobj will be set to the * kobject associated with the kset assigned to this kobject.  If no kset * is assigned to the kobject, then the kobject will be located in the * root of the sysfs tree. * * If this function returns an error, kobject_put() must be called to * properly clean up the memory associated with the object. * Under no instance should the kobject that is passed to this function * be directly freed with a call to kfree(), that can leak memory. * * Note, no "add" uevent will be created with this call, the caller should set * up all of the necessary sysfs files for the object and then call * kobject_uevent() with the UEVENT_ADD parameter to ensure that * userspace is properly notified of this kobject's creation. */int kobject_add(struct kobject *kobj, struct kobject *parent,		const char *fmt, ...){	va_list args;	int retval; 	if (!kobj)		return -EINVAL; 	if (!kobj->state_initialized) {		printk(KERN_ERR "kobject '%s' (%p): tried to add an "		       "uninitialized object, something is seriously wrong.\n",		       kobject_name(kobj), kobj);		dump_stack();		return -EINVAL;	}	va_start(args, fmt);	retval = kobject_add_varg(kobj, parent, fmt, args);	va_end(args); 	return retval;}EXPORT_SYMBOL(kobject_add); /** * kobject_init_and_add - initialize a kobject structure and add it to the kobject hierarchy * @kobj: pointer to the kobject to initialize * @ktype: pointer to the ktype for this kobject. * @parent: pointer to the parent of this kobject. * @fmt: the name of the kobject. * * This function combines the call to kobject_init() and * kobject_add().  The same type of error handling after a call to * kobject_add() and kobject lifetime rules are the same here. */int kobject_init_and_add(struct kobject *kobj, struct kobj_type *ktype,			 struct kobject *parent, const char *fmt, ...){	va_list args;	int retval; 	kobject_init(kobj, ktype); 	va_start(args, fmt);	retval = kobject_add_varg(kobj, parent, fmt, args);	va_end(args); 	return retval;}EXPORT_SYMBOL_GPL(kobject_init_and_add); /** * kobject_rename - change the name of an object * @kobj: object in question. * @new_name: object's new name * * It is the responsibility of the caller to provide mutual * exclusion between two different calls of kobject_rename * on the same kobject and to ensure that new_name is valid and * won't conflict with other kobjects. */int kobject_rename(struct kobject *kobj, const char *new_name){	int error = 0;	const char *devpath = NULL;	const char *dup_name = NULL, *name;	char *devpath_string = NULL;	char *envp[2]; 	kobj = kobject_get(kobj);	if (!kobj)		return -EINVAL;	if (!kobj->parent)		return -EINVAL; 	devpath = kobject_get_path(kobj, GFP_KERNEL);	if (!devpath) {		error = -ENOMEM;		goto out;	}	devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL);	if (!devpath_string) {		error = -ENOMEM;		goto out;	}	sprintf(devpath_string, "DEVPATH_OLD=%s", devpath);	envp[0] = devpath_string;	envp[1] = NULL; 	name = dup_name = kstrdup_const(new_name, GFP_KERNEL);	if (!name) {		error = -ENOMEM;		goto out;	} 	error = sysfs_rename_dir_ns(kobj, new_name, kobject_namespace(kobj));	if (error)		goto out; 	/* Install the new kobject name */	dup_name = kobj->name;	kobj->name = name; 	/* This function is mostly/only used for network interface.	 * Some hotplug package track interfaces by their name and	 * therefore want to know when the name is changed by the user. */	kobject_uevent_env(kobj, KOBJ_MOVE, envp);

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