FreeBSD/Linux Kernel Cross Reference
sys/lib/kobject.c

     /*
      * 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>
    
    /*
     * 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)
    {
            int error = 0;
            error = sysfs_create_dir(kobj);
            if (!error) {
                    error = populate_dir(kobj);
                    if (error)
                            sysfs_remove_dir(kobj);
            }
            return error;
    }
    
    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 *old_name = kobj->name;
           char *s;
   
           if (kobj->name && !fmt)
                   return 0;
   
           kobj->name = kvasprintf(GFP_KERNEL, fmt, vargs);
           if (!kobj->name)
                   return -ENOMEM;
   
           /* ewww... some of these buggers have '/' in the name ... */
           while ((s = strchr(kobj->name, '/')))
                   s[0] = '!';
   
           kfree(old_name);
           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 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 associted 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(new_name, GFP_KERNEL);
           if (!name) {
                   error = -ENOMEM;
                   goto out;
           }
   
           error = sysfs_rename_dir(kobj, new_name);
           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);
   
   out:
           kfree(dup_name);
           kfree(devpath_string);
           kfree(devpath);
           kobject_put(kobj);
   
           return error;
   }
   EXPORT_SYMBOL_GPL(kobject_rename);
   
   /**
    * kobject_move - move object to another parent
    * @kobj: object in question.
    * @new_parent: object's new parent (can be NULL)
    */
   int kobject_move(struct kobject *kobj, struct kobject *new_parent)
   {
           int error;
           struct kobject *old_parent;
           const char *devpath = NULL;
           char *devpath_string = NULL;
           char *envp[2];
   
           kobj = kobject_get(kobj);
           if (!kobj)
                   return -EINVAL;
           new_parent = kobject_get(new_parent);
           if (!new_parent) {
                   if (kobj->kset)
                           new_parent = kobject_get(&kobj->kset->kobj);
           }
           /* old object path */
           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;
           error = sysfs_move_dir(kobj, new_parent);
           if (error)
                   goto out;
           old_parent = kobj->parent;
           kobj->parent = new_parent;
           new_parent = NULL;
           kobject_put(old_parent);
           kobject_uevent_env(kobj, KOBJ_MOVE, envp);
   out:
           kobject_put(new_parent);
           kobject_put(kobj);
           kfree(devpath_string);
           kfree(devpath);
           return error;
   }
   
   /**
    * kobject_del - unlink kobject from hierarchy.
    * @kobj: object.
    */
   void kobject_del(struct kobject *kobj)
   {
           if (!kobj)
                   return;
   
           sysfs_remove_dir(kobj);
           kobj->state_in_sysfs = 0;
           kobj_kset_leave(kobj);
           kobject_put(kobj->parent);
           kobj->parent = NULL;
   }
   
   /**
    * kobject_get - increment refcount for object.
    * @kobj: object.
    */
   struct kobject *kobject_get(struct kobject *kobj)
   {
           if (kobj)
                   kref_get(&kobj->kref);
           return kobj;
   }
   
   /*
    * kobject_cleanup - free kobject resources.
    * @kobj: object to cleanup
    */
   static void kobject_cleanup(struct kobject *kobj)
   {
           struct kobj_type *t = get_ktype(kobj);
           const char *name = kobj->name;
   
           pr_debug("kobject: '%s' (%p): %s\n",
                    kobject_name(kobj), kobj, __func__);
   
           if (t && !t->release)
                   pr_debug("kobject: '%s' (%p): does not have a release() "
                            "function, it is broken and must be fixed.\n",
                            kobject_name(kobj), kobj);
   
           /* send "remove" if the caller did not do it but sent "add" */
           if (kobj->state_add_uevent_sent && !kobj->state_remove_uevent_sent) {
                   pr_debug("kobject: '%s' (%p): auto cleanup 'remove' event\n",
                            kobject_name(kobj), kobj);
                   kobject_uevent(kobj, KOBJ_REMOVE);
           }
   
           /* remove from sysfs if the caller did not do it */
           if (kobj->state_in_sysfs) {
                   pr_debug("kobject: '%s' (%p): auto cleanup kobject_del\n",
                            kobject_name(kobj), kobj);
                   kobject_del(kobj);
           }
   
           if (t && t->release) {
                   pr_debug("kobject: '%s' (%p): calling ktype release\n",
                            kobject_name(kobj), kobj);
                   t->release(kobj);
           }
   
           /* free name if we allocated it */
           if (name) {
                   pr_debug("kobject: '%s': free name\n", name);
                   kfree(name);
           }
   }
   
   static void kobject_release(struct kref *kref)
   {
           kobject_cleanup(container_of(kref, struct kobject, kref));
   }
   
   /**
    * kobject_put - decrement refcount for object.
    * @kobj: object.
    *
    * Decrement the refcount, and if 0, call kobject_cleanup().
    */
   void kobject_put(struct kobject *kobj)
   {
           if (kobj) {
                   if (!kobj->state_initialized)
                           WARN(1, KERN_WARNING "kobject: '%s' (%p): is not "
                                  "initialized, yet kobject_put() is being "
                                  "called.\n", kobject_name(kobj), kobj);
                   kref_put(&kobj->kref, kobject_release);
           }
   }
   
   static void dynamic_kobj_release(struct kobject *kobj)
   {
           pr_debug("kobject: (%p): %s\n", kobj, __func__);
           kfree(kobj);
   }
   
   static struct kobj_type dynamic_kobj_ktype = {
           .release        = dynamic_kobj_release,
           .sysfs_ops      = &kobj_sysfs_ops,
   };
   
   /**
    * kobject_create - create a struct kobject dynamically
    *
    * This function creates a kobject structure dynamically and sets it up
    * to be a "dynamic" kobject with a default release function set up.
    *
    * If the kobject was not able to be created, NULL will be returned.
    * The kobject structure returned from here must be cleaned up with a
    * call to kobject_put() and not kfree(), as kobject_init() has
    * already been called on this structure.
    */
   struct kobject *kobject_create(void)
   {
           struct kobject *kobj;
   
           kobj = kzalloc(sizeof(*kobj), GFP_KERNEL);
           if (!kobj)
                   return NULL;
   
           kobject_init(kobj, &dynamic_kobj_ktype);
           return kobj;
   }
   
   /**
    * kobject_create_and_add - create a struct kobject dynamically and register it with sysfs
    *
    * @name: the name for the kobject
    * @parent: the parent kobject of this kobject, if any.
    *
    * This function creates a kobject structure dynamically and registers it
    * with sysfs.  When you are finished with this structure, call
    * kobject_put() and the structure will be dynamically freed when
    * it is no longer being used.
    *
    * If the kobject was not able to be created, NULL will be returned.
    */
   struct kobject *kobject_create_and_add(const char *name, struct kobject *parent)
   {
           struct kobject *kobj;
           int retval;
   
           kobj = kobject_create();
           if (!kobj)
                   return NULL;
   
           retval = kobject_add(kobj, parent, "%s", name);
           if (retval) {
                   printk(KERN_WARNING "%s: kobject_add error: %d\n",
                          __func__, retval);
                   kobject_put(kobj);
                   kobj = NULL;
           }
           return kobj;
   }
   EXPORT_SYMBOL_GPL(kobject_create_and_add);
   
   /**
    * kset_init - initialize a kset for use
    * @k: kset
    */
   void kset_init(struct kset *k)
   {
           kobject_init_internal(&k->kobj);
           INIT_LIST_HEAD(&k->list);
           spin_lock_init(&k->list_lock);
   }
   
   /* default kobject attribute operations */
   static ssize_t kobj_attr_show(struct kobject *kobj, struct attribute *attr,
                                 char *buf)
   {
           struct kobj_attribute *kattr;
           ssize_t ret = -EIO;
   
           kattr = container_of(attr, struct kobj_attribute, attr);
           if (kattr->show)
                   ret = kattr->show(kobj, kattr, buf);
           return ret;
   }
   
   static ssize_t kobj_attr_store(struct kobject *kobj, struct attribute *attr,
                                  const char *buf, size_t count)
   {
           struct kobj_attribute *kattr;
           ssize_t ret = -EIO;
   
           kattr = container_of(attr, struct kobj_attribute, attr);
           if (kattr->store)
                   ret = kattr->store(kobj, kattr, buf, count);
           return ret;
   }
   
   const struct sysfs_ops kobj_sysfs_ops = {
           .show   = kobj_attr_show,
           .store  = kobj_attr_store,
   };
   
   /**
    * kset_register - initialize and add a kset.
    * @k: kset.
    */
   int kset_register(struct kset *k)
   {
           int err;
   
           if (!k)
                   return -EINVAL;
   
           kset_init(k);
           err = kobject_add_internal(&k->kobj);
           if (err)
                   return err;
           kobject_uevent(&k->kobj, KOBJ_ADD);
           return 0;
   }
   
   /**
    * kset_unregister - remove a kset.
    * @k: kset.
    */
   void kset_unregister(struct kset *k)
   {
           if (!k)
                   return;
           kobject_put(&k->kobj);
   }
   
   /**
    * kset_find_obj - search for object in kset.
    * @kset: kset we're looking in.
    * @name: object's name.
    *
    * Lock kset via @kset->subsys, and iterate over @kset->list,
    * looking for a matching kobject. If matching object is found
    * take a reference and return the object.
    */
   struct kobject *kset_find_obj(struct kset *kset, const char *name)
   {
           struct kobject *k;
           struct kobject *ret = NULL;
   
           spin_lock(&kset->list_lock);
   
           list_for_each_entry(k, &kset->list, entry) {
                   if (kobject_name(k) && !strcmp(kobject_name(k), name)) {
                           ret = kobject_get(k);
                           break;
                   }
           }
   
           spin_unlock(&kset->list_lock);
           return ret;
   }
   
   static void kset_release(struct kobject *kobj)
   {
           struct kset *kset = container_of(kobj, struct kset, kobj);
           pr_debug("kobject: '%s' (%p): %s\n",
                    kobject_name(kobj), kobj, __func__);
           kfree(kset);
   }
   
   static struct kobj_type kset_ktype = {
           .sysfs_ops      = &kobj_sysfs_ops,
           .release = kset_release,
   };
   
   /**
    * kset_create - create a struct kset dynamically
    *
    * @name: the name for the kset
    * @uevent_ops: a struct kset_uevent_ops for the kset
    * @parent_kobj: the parent kobject of this kset, if any.
    *
    * This function creates a kset structure dynamically.  This structure can
    * then be registered with the system and show up in sysfs with a call to
    * kset_register().  When you are finished with this structure, if
    * kset_register() has been called, call kset_unregister() and the
    * structure will be dynamically freed when it is no longer being used.
    *
    * If the kset was not able to be created, NULL will be returned.
    */
   static struct kset *kset_create(const char *name,
                                   const struct kset_uevent_ops *uevent_ops,
                                   struct kobject *parent_kobj)
   {
           struct kset *kset;
           int retval;
   
           kset = kzalloc(sizeof(*kset), GFP_KERNEL);
           if (!kset)
                   return NULL;
           retval = kobject_set_name(&kset->kobj, name);
           if (retval) {
                   kfree(kset);
                   return NULL;
           }
           kset->uevent_ops = uevent_ops;
           kset->kobj.parent = parent_kobj;
   
           /*
            * The kobject of this kset will have a type of kset_ktype and belong to
            * no kset itself.  That way we can properly free it when it is
            * finished being used.
            */
           kset->kobj.ktype = &kset_ktype;
           kset->kobj.kset = NULL;
   
           return kset;
   }
   
   /**
    * kset_create_and_add - create a struct kset dynamically and add it to sysfs
    *
    * @name: the name for the kset
    * @uevent_ops: a struct kset_uevent_ops for the kset
    * @parent_kobj: the parent kobject of this kset, if any.
    *
    * This function creates a kset structure dynamically and registers it
    * with sysfs.  When you are finished with this structure, call
    * kset_unregister() and the structure will be dynamically freed when it
    * is no longer being used.
    *
    * If the kset was not able to be created, NULL will be returned.
    */
   struct kset *kset_create_and_add(const char *name,
                                    const struct kset_uevent_ops *uevent_ops,
                                    struct kobject *parent_kobj)
   {
           struct kset *kset;
           int error;
   
           kset = kset_create(name, uevent_ops, parent_kobj);
           if (!kset)
                   return NULL;
           error = kset_register(kset);
           if (error) {
                   kfree(kset);
                   return NULL;
           }
           return kset;
   }
   EXPORT_SYMBOL_GPL(kset_create_and_add);
   
   
   static DEFINE_SPINLOCK(kobj_ns_type_lock);
   static const struct kobj_ns_type_operations *kobj_ns_ops_tbl[KOBJ_NS_TYPES];
   
   int kobj_ns_type_register(const struct kobj_ns_type_operations *ops)
   {
           enum kobj_ns_type type = ops->type;
           int error;
   
           spin_lock(&kobj_ns_type_lock);
   
           error = -EINVAL;
           if (type >= KOBJ_NS_TYPES)
                   goto out;
   
           error = -EINVAL;
           if (type <= KOBJ_NS_TYPE_NONE)
                   goto out;
   
           error = -EBUSY;
           if (kobj_ns_ops_tbl[type])
                   goto out;
   
           error = 0;
           kobj_ns_ops_tbl[type] = ops;
   
   out:
           spin_unlock(&kobj_ns_type_lock);
           return error;
   }
   
   int kobj_ns_type_registered(enum kobj_ns_type type)
   {
           int registered = 0;
   
           spin_lock(&kobj_ns_type_lock);
           if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES))
                   registered = kobj_ns_ops_tbl[type] != NULL;
           spin_unlock(&kobj_ns_type_lock);
   
           return registered;
   }
   
   const struct kobj_ns_type_operations *kobj_child_ns_ops(struct kobject *parent)
   {
           const struct kobj_ns_type_operations *ops = NULL;
   
           if (parent && parent->ktype->child_ns_type)
                   ops = parent->ktype->child_ns_type(parent);
   
           return ops;
   }
   
   const struct kobj_ns_type_operations *kobj_ns_ops(struct kobject *kobj)
   {
           return kobj_child_ns_ops(kobj->parent);
   }
   
   
   void *kobj_ns_grab_current(enum kobj_ns_type type)
   {
           void *ns = NULL;
   
           spin_lock(&kobj_ns_type_lock);
           if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
               kobj_ns_ops_tbl[type])
                   ns = kobj_ns_ops_tbl[type]->grab_current_ns();
           spin_unlock(&kobj_ns_type_lock);
   
           return ns;
   }
   
   const void *kobj_ns_netlink(enum kobj_ns_type type, struct sock *sk)
   {
           const void *ns = NULL;
   
           spin_lock(&kobj_ns_type_lock);
           if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
               kobj_ns_ops_tbl[type])
                   ns = kobj_ns_ops_tbl[type]->netlink_ns(sk);
           spin_unlock(&kobj_ns_type_lock);
   
           return ns;
   }
   
   const void *kobj_ns_initial(enum kobj_ns_type type)
   {
           const void *ns = NULL;
   
           spin_lock(&kobj_ns_type_lock);
           if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
               kobj_ns_ops_tbl[type])
                   ns = kobj_ns_ops_tbl[type]->initial_ns();
           spin_unlock(&kobj_ns_type_lock);
   
           return ns;
   }
   
   void kobj_ns_drop(enum kobj_ns_type type, void *ns)
   {
           spin_lock(&kobj_ns_type_lock);
           if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
               kobj_ns_ops_tbl[type] && kobj_ns_ops_tbl[type]->drop_ns)
                   kobj_ns_ops_tbl[type]->drop_ns(ns);
           spin_unlock(&kobj_ns_type_lock);
   }
   
   EXPORT_SYMBOL(kobject_get);
   EXPORT_SYMBOL(kobject_put);
   EXPORT_SYMBOL(kobject_del);
   
   EXPORT_SYMBOL(kset_register);
   EXPORT_SYMBOL(kset_unregister);

Cache object: 655174a97c2a51471d9c4b4314c9d8f2