linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * 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.

 *

 * 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);

}

​

/**

 * kobject_get_ownership - get sysfs ownership data for @kobj

 * @kobj: kobject in question

 * @uid: kernel user ID for sysfs objects

 * @gid: kernel group ID for sysfs objects

 *

 * Returns initial uid/gid pair that should be used when creating sysfs

 * representation of given kobject. Normally used to adjust ownership of

 * objects in a container.

 */

void kobject_get_ownership(struct kobject *kobj, kuid_t *uid, kgid_t *gid)

{

    *uid = GLOBAL_ROOT_UID;

    *gid = GLOBAL_ROOT_GID;

​

    if (kobj->ktype->get_ownership)

        kobj->ktype->get_ownership(kobj, uid, gid);

}

​

/*

 * 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);