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c70c176ff8
Make the function available for outside use and fortify it against NULL kobject. CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
1077 lines
26 KiB
C
1077 lines
26 KiB
C
/*
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* kobject.c - library routines for handling generic kernel objects
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*
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* Copyright (c) 2002-2003 Patrick Mochel <mochel@osdl.org>
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* Copyright (c) 2006-2007 Greg Kroah-Hartman <greg@kroah.com>
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* Copyright (c) 2006-2007 Novell Inc.
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*
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* This file is released under the GPLv2.
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*
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*
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* Please see the file Documentation/kobject.txt for critical information
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* about using the kobject interface.
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*/
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#include <linux/kobject.h>
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#include <linux/string.h>
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#include <linux/export.h>
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#include <linux/stat.h>
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#include <linux/slab.h>
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#include <linux/random.h>
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/**
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* kobject_namespace - return @kobj's namespace tag
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* @kobj: kobject in question
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*
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* Returns namespace tag of @kobj if its parent has namespace ops enabled
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* and thus @kobj should have a namespace tag associated with it. Returns
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* %NULL otherwise.
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*/
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const void *kobject_namespace(struct kobject *kobj)
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{
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const struct kobj_ns_type_operations *ns_ops = kobj_ns_ops(kobj);
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if (!ns_ops || ns_ops->type == KOBJ_NS_TYPE_NONE)
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return NULL;
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return kobj->ktype->namespace(kobj);
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}
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/*
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* populate_dir - populate directory with attributes.
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* @kobj: object we're working on.
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*
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* Most subsystems have a set of default attributes that are associated
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* with an object that registers with them. This is a helper called during
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* object registration that loops through the default attributes of the
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* subsystem and creates attributes files for them in sysfs.
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*/
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static int populate_dir(struct kobject *kobj)
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{
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struct kobj_type *t = get_ktype(kobj);
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struct attribute *attr;
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int error = 0;
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int i;
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if (t && t->default_attrs) {
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for (i = 0; (attr = t->default_attrs[i]) != NULL; i++) {
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error = sysfs_create_file(kobj, attr);
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if (error)
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break;
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}
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}
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return error;
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}
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static int create_dir(struct kobject *kobj)
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{
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const struct kobj_ns_type_operations *ops;
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int error;
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error = sysfs_create_dir_ns(kobj, kobject_namespace(kobj));
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if (error)
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return error;
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error = populate_dir(kobj);
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if (error) {
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sysfs_remove_dir(kobj);
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return error;
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}
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/*
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* @kobj->sd may be deleted by an ancestor going away. Hold an
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* extra reference so that it stays until @kobj is gone.
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*/
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sysfs_get(kobj->sd);
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/*
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* If @kobj has ns_ops, its children need to be filtered based on
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* their namespace tags. Enable namespace support on @kobj->sd.
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*/
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ops = kobj_child_ns_ops(kobj);
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if (ops) {
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BUG_ON(ops->type <= KOBJ_NS_TYPE_NONE);
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BUG_ON(ops->type >= KOBJ_NS_TYPES);
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BUG_ON(!kobj_ns_type_registered(ops->type));
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sysfs_enable_ns(kobj->sd);
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}
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return 0;
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}
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static int get_kobj_path_length(struct kobject *kobj)
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{
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int length = 1;
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struct kobject *parent = kobj;
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/* walk up the ancestors until we hit the one pointing to the
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* root.
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* Add 1 to strlen for leading '/' of each level.
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*/
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do {
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if (kobject_name(parent) == NULL)
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return 0;
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length += strlen(kobject_name(parent)) + 1;
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parent = parent->parent;
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} while (parent);
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return length;
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}
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static void fill_kobj_path(struct kobject *kobj, char *path, int length)
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{
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struct kobject *parent;
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--length;
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for (parent = kobj; parent; parent = parent->parent) {
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int cur = strlen(kobject_name(parent));
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/* back up enough to print this name with '/' */
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length -= cur;
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strncpy(path + length, kobject_name(parent), cur);
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*(path + --length) = '/';
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}
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pr_debug("kobject: '%s' (%p): %s: path = '%s'\n", kobject_name(kobj),
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kobj, __func__, path);
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}
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/**
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* kobject_get_path - generate and return the path associated with a given kobj and kset pair.
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*
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* @kobj: kobject in question, with which to build the path
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* @gfp_mask: the allocation type used to allocate the path
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*
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* The result must be freed by the caller with kfree().
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*/
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char *kobject_get_path(struct kobject *kobj, gfp_t gfp_mask)
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{
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char *path;
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int len;
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len = get_kobj_path_length(kobj);
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if (len == 0)
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return NULL;
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path = kzalloc(len, gfp_mask);
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if (!path)
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return NULL;
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fill_kobj_path(kobj, path, len);
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return path;
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}
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EXPORT_SYMBOL_GPL(kobject_get_path);
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/* add the kobject to its kset's list */
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static void kobj_kset_join(struct kobject *kobj)
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{
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if (!kobj->kset)
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return;
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kset_get(kobj->kset);
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spin_lock(&kobj->kset->list_lock);
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list_add_tail(&kobj->entry, &kobj->kset->list);
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spin_unlock(&kobj->kset->list_lock);
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}
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/* remove the kobject from its kset's list */
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static void kobj_kset_leave(struct kobject *kobj)
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{
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if (!kobj->kset)
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return;
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spin_lock(&kobj->kset->list_lock);
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list_del_init(&kobj->entry);
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spin_unlock(&kobj->kset->list_lock);
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kset_put(kobj->kset);
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}
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static void kobject_init_internal(struct kobject *kobj)
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{
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if (!kobj)
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return;
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kref_init(&kobj->kref);
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INIT_LIST_HEAD(&kobj->entry);
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kobj->state_in_sysfs = 0;
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kobj->state_add_uevent_sent = 0;
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kobj->state_remove_uevent_sent = 0;
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kobj->state_initialized = 1;
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}
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static int kobject_add_internal(struct kobject *kobj)
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{
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int error = 0;
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struct kobject *parent;
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if (!kobj)
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return -ENOENT;
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if (!kobj->name || !kobj->name[0]) {
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WARN(1, "kobject: (%p): attempted to be registered with empty "
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"name!\n", kobj);
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return -EINVAL;
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}
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parent = kobject_get(kobj->parent);
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/* join kset if set, use it as parent if we do not already have one */
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if (kobj->kset) {
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if (!parent)
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parent = kobject_get(&kobj->kset->kobj);
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kobj_kset_join(kobj);
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kobj->parent = parent;
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}
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pr_debug("kobject: '%s' (%p): %s: parent: '%s', set: '%s'\n",
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kobject_name(kobj), kobj, __func__,
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parent ? kobject_name(parent) : "<NULL>",
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kobj->kset ? kobject_name(&kobj->kset->kobj) : "<NULL>");
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error = create_dir(kobj);
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if (error) {
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kobj_kset_leave(kobj);
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kobject_put(parent);
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kobj->parent = NULL;
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/* be noisy on error issues */
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if (error == -EEXIST)
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WARN(1, "%s failed for %s with "
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"-EEXIST, don't try to register things with "
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"the same name in the same directory.\n",
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__func__, kobject_name(kobj));
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else
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WARN(1, "%s failed for %s (error: %d parent: %s)\n",
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__func__, kobject_name(kobj), error,
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parent ? kobject_name(parent) : "'none'");
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} else
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kobj->state_in_sysfs = 1;
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return error;
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}
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/**
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* kobject_set_name_vargs - Set the name of an kobject
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* @kobj: struct kobject to set the name of
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* @fmt: format string used to build the name
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* @vargs: vargs to format the string.
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*/
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int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
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va_list vargs)
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{
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const char *s;
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if (kobj->name && !fmt)
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return 0;
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s = kvasprintf_const(GFP_KERNEL, fmt, vargs);
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if (!s)
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return -ENOMEM;
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/*
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* ewww... some of these buggers have '/' in the name ... If
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* that's the case, we need to make sure we have an actual
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* allocated copy to modify, since kvasprintf_const may have
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* returned something from .rodata.
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*/
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if (strchr(s, '/')) {
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char *t;
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t = kstrdup(s, GFP_KERNEL);
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kfree_const(s);
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if (!t)
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return -ENOMEM;
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strreplace(t, '/', '!');
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s = t;
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}
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kfree_const(kobj->name);
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kobj->name = s;
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return 0;
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}
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/**
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* kobject_set_name - Set the name of a kobject
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* @kobj: struct kobject to set the name of
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* @fmt: format string used to build the name
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*
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* This sets the name of the kobject. If you have already added the
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* kobject to the system, you must call kobject_rename() in order to
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* change the name of the kobject.
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*/
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int kobject_set_name(struct kobject *kobj, const char *fmt, ...)
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{
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va_list vargs;
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int retval;
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va_start(vargs, fmt);
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retval = kobject_set_name_vargs(kobj, fmt, vargs);
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va_end(vargs);
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return retval;
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}
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EXPORT_SYMBOL(kobject_set_name);
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/**
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* kobject_init - initialize a kobject structure
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* @kobj: pointer to the kobject to initialize
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* @ktype: pointer to the ktype for this kobject.
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*
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* This function will properly initialize a kobject such that it can then
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* be passed to the kobject_add() call.
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*
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* After this function is called, the kobject MUST be cleaned up by a call
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* to kobject_put(), not by a call to kfree directly to ensure that all of
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* the memory is cleaned up properly.
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*/
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void kobject_init(struct kobject *kobj, struct kobj_type *ktype)
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{
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char *err_str;
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if (!kobj) {
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err_str = "invalid kobject pointer!";
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goto error;
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}
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if (!ktype) {
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err_str = "must have a ktype to be initialized properly!\n";
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goto error;
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}
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if (kobj->state_initialized) {
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/* do not error out as sometimes we can recover */
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printk(KERN_ERR "kobject (%p): tried to init an initialized "
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"object, something is seriously wrong.\n", kobj);
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dump_stack();
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}
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kobject_init_internal(kobj);
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kobj->ktype = ktype;
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return;
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error:
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printk(KERN_ERR "kobject (%p): %s\n", kobj, err_str);
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dump_stack();
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}
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EXPORT_SYMBOL(kobject_init);
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static __printf(3, 0) int kobject_add_varg(struct kobject *kobj,
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struct kobject *parent,
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const char *fmt, va_list vargs)
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{
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int retval;
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retval = kobject_set_name_vargs(kobj, fmt, vargs);
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if (retval) {
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printk(KERN_ERR "kobject: can not set name properly!\n");
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return retval;
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}
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kobj->parent = parent;
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return kobject_add_internal(kobj);
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}
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/**
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* kobject_add - the main kobject add function
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* @kobj: the kobject to add
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* @parent: pointer to the parent of the kobject.
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* @fmt: format to name the kobject with.
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*
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* The kobject name is set and added to the kobject hierarchy in this
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* function.
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*
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* If @parent is set, then the parent of the @kobj will be set to it.
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* If @parent is NULL, then the parent of the @kobj will be set to the
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* kobject associated with the kset assigned to this kobject. If no kset
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* is assigned to the kobject, then the kobject will be located in the
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* root of the sysfs tree.
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*
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* If this function returns an error, kobject_put() must be called to
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* properly clean up the memory associated with the object.
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* Under no instance should the kobject that is passed to this function
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* be directly freed with a call to kfree(), that can leak memory.
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*
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* Note, no "add" uevent will be created with this call, the caller should set
|
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* up all of the necessary sysfs files for the object and then call
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* kobject_uevent() with the UEVENT_ADD parameter to ensure that
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* userspace is properly notified of this kobject's creation.
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*/
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int kobject_add(struct kobject *kobj, struct kobject *parent,
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const char *fmt, ...)
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{
|
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va_list args;
|
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int retval;
|
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|
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if (!kobj)
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return -EINVAL;
|
|
|
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if (!kobj->state_initialized) {
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printk(KERN_ERR "kobject '%s' (%p): tried to add an "
|
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"uninitialized object, something is seriously wrong.\n",
|
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kobject_name(kobj), kobj);
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dump_stack();
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return -EINVAL;
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}
|
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va_start(args, fmt);
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retval = kobject_add_varg(kobj, parent, fmt, args);
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va_end(args);
|
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|
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return retval;
|
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}
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EXPORT_SYMBOL(kobject_add);
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|
|
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/**
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* kobject_init_and_add - initialize a kobject structure and add it to the kobject hierarchy
|
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* @kobj: pointer to the kobject to initialize
|
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* @ktype: pointer to the ktype for this kobject.
|
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* @parent: pointer to the parent of this kobject.
|
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* @fmt: the name of the kobject.
|
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*
|
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* This function combines the call to kobject_init() and
|
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* kobject_add(). The same type of error handling after a call to
|
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* kobject_add() and kobject lifetime rules are the same here.
|
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*/
|
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int kobject_init_and_add(struct kobject *kobj, struct kobj_type *ktype,
|
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struct kobject *parent, const char *fmt, ...)
|
|
{
|
|
va_list args;
|
|
int retval;
|
|
|
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kobject_init(kobj, ktype);
|
|
|
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va_start(args, fmt);
|
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retval = kobject_add_varg(kobj, parent, fmt, args);
|
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va_end(args);
|
|
|
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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
|
|
*
|
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* 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);
|
|
|
|
out:
|
|
kfree_const(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_ns(kobj, new_parent, kobject_namespace(kobj));
|
|
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;
|
|
}
|
|
EXPORT_SYMBOL_GPL(kobject_move);
|
|
|
|
/**
|
|
* kobject_del - unlink kobject from hierarchy.
|
|
* @kobj: object.
|
|
*/
|
|
void kobject_del(struct kobject *kobj)
|
|
{
|
|
struct kernfs_node *sd;
|
|
|
|
if (!kobj)
|
|
return;
|
|
|
|
sd = kobj->sd;
|
|
sysfs_remove_dir(kobj);
|
|
sysfs_put(sd);
|
|
|
|
kobj->state_in_sysfs = 0;
|
|
kobj_kset_leave(kobj);
|
|
kobject_put(kobj->parent);
|
|
kobj->parent = NULL;
|
|
}
|
|
EXPORT_SYMBOL(kobject_del);
|
|
|
|
/**
|
|
* kobject_get - increment refcount for object.
|
|
* @kobj: object.
|
|
*/
|
|
struct kobject *kobject_get(struct kobject *kobj)
|
|
{
|
|
if (kobj) {
|
|
if (!kobj->state_initialized)
|
|
WARN(1, KERN_WARNING "kobject: '%s' (%p): is not "
|
|
"initialized, yet kobject_get() is being "
|
|
"called.\n", kobject_name(kobj), kobj);
|
|
kref_get(&kobj->kref);
|
|
}
|
|
return kobj;
|
|
}
|
|
EXPORT_SYMBOL(kobject_get);
|
|
|
|
struct kobject * __must_check kobject_get_unless_zero(struct kobject *kobj)
|
|
{
|
|
if (!kobj)
|
|
return NULL;
|
|
if (!kref_get_unless_zero(&kobj->kref))
|
|
kobj = NULL;
|
|
return kobj;
|
|
}
|
|
EXPORT_SYMBOL(kobject_get_unless_zero);
|
|
|
|
/*
|
|
* 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, parent %p\n",
|
|
kobject_name(kobj), kobj, __func__, kobj->parent);
|
|
|
|
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_const(name);
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_DEBUG_KOBJECT_RELEASE
|
|
static void kobject_delayed_cleanup(struct work_struct *work)
|
|
{
|
|
kobject_cleanup(container_of(to_delayed_work(work),
|
|
struct kobject, release));
|
|
}
|
|
#endif
|
|
|
|
static void kobject_release(struct kref *kref)
|
|
{
|
|
struct kobject *kobj = container_of(kref, struct kobject, kref);
|
|
#ifdef CONFIG_DEBUG_KOBJECT_RELEASE
|
|
unsigned long delay = HZ + HZ * (get_random_int() & 0x3);
|
|
pr_info("kobject: '%s' (%p): %s, parent %p (delayed %ld)\n",
|
|
kobject_name(kobj), kobj, __func__, kobj->parent, delay);
|
|
INIT_DELAYED_WORK(&kobj->release, kobject_delayed_cleanup);
|
|
|
|
schedule_delayed_work(&kobj->release, delay);
|
|
#else
|
|
kobject_cleanup(kobj);
|
|
#endif
|
|
}
|
|
|
|
/**
|
|
* 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);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(kobject_put);
|
|
|
|
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,
|
|
};
|
|
EXPORT_SYMBOL_GPL(kobj_sysfs_ops);
|
|
|
|
/**
|
|
* 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;
|
|
}
|
|
EXPORT_SYMBOL(kset_register);
|
|
|
|
/**
|
|
* kset_unregister - remove a kset.
|
|
* @k: kset.
|
|
*/
|
|
void kset_unregister(struct kset *k)
|
|
{
|
|
if (!k)
|
|
return;
|
|
kobject_del(&k->kobj);
|
|
kobject_put(&k->kobj);
|
|
}
|
|
EXPORT_SYMBOL(kset_unregister);
|
|
|
|
/**
|
|
* 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_unless_zero(k);
|
|
break;
|
|
}
|
|
}
|
|
|
|
spin_unlock(&kset->list_lock);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(kset_find_obj);
|
|
|
|
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, "%s", 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 && 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);
|
|
}
|
|
|
|
bool kobj_ns_current_may_mount(enum kobj_ns_type type)
|
|
{
|
|
bool may_mount = true;
|
|
|
|
spin_lock(&kobj_ns_type_lock);
|
|
if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
|
|
kobj_ns_ops_tbl[type])
|
|
may_mount = kobj_ns_ops_tbl[type]->current_may_mount();
|
|
spin_unlock(&kobj_ns_type_lock);
|
|
|
|
return may_mount;
|
|
}
|
|
|
|
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);
|
|
}
|