summaryrefslogtreecommitdiffstats
path: root/lib/kobject.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/kobject.c')
-rw-r--r--lib/kobject.c1127
1 files changed, 1127 insertions, 0 deletions
diff --git a/lib/kobject.c b/lib/kobject.c
new file mode 100644
index 0000000000..59dbcbdb1c
--- /dev/null
+++ b/lib/kobject.c
@@ -0,0 +1,1127 @@
+// 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/core-api/kobject.rst for critical information
+ * about using the kobject interface.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#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(const 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(const 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);
+}
+
+static bool kobj_ns_type_is_valid(enum kobj_ns_type type)
+{
+ if ((type <= KOBJ_NS_TYPE_NONE) || (type >= KOBJ_NS_TYPES))
+ return false;
+
+ return true;
+}
+
+static int create_dir(struct kobject *kobj)
+{
+ const struct kobj_type *ktype = get_ktype(kobj);
+ const struct kobj_ns_type_operations *ops;
+ int error;
+
+ error = sysfs_create_dir_ns(kobj, kobject_namespace(kobj));
+ if (error)
+ return error;
+
+ error = sysfs_create_groups(kobj, ktype->default_groups);
+ 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(!kobj_ns_type_is_valid(ops->type));
+ BUG_ON(!kobj_ns_type_registered(ops->type));
+
+ sysfs_enable_ns(kobj->sd);
+ }
+
+ return 0;
+}
+
+static int get_kobj_path_length(const struct kobject *kobj)
+{
+ int length = 1;
+ const 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 int fill_kobj_path(const struct kobject *kobj, char *path, int length)
+{
+ const 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;
+ if (length <= 0)
+ return -EINVAL;
+ memcpy(path + length, kobject_name(parent), cur);
+ *(path + --length) = '/';
+ }
+
+ pr_debug("'%s' (%p): %s: path = '%s'\n", kobject_name(kobj),
+ kobj, __func__, path);
+
+ return 0;
+}
+
+/**
+ * kobject_get_path() - Allocate memory and fill in the path for @kobj.
+ * @kobj: kobject in question, with which to build the path
+ * @gfp_mask: the allocation type used to allocate the path
+ *
+ * Return: The newly allocated memory, caller must free with kfree().
+ */
+char *kobject_get_path(const struct kobject *kobj, gfp_t gfp_mask)
+{
+ char *path;
+ int len;
+
+retry:
+ len = get_kobj_path_length(kobj);
+ if (len == 0)
+ return NULL;
+ path = kzalloc(len, gfp_mask);
+ if (!path)
+ return NULL;
+ if (fill_kobj_path(kobj, path, len)) {
+ kfree(path);
+ goto retry;
+ }
+
+ 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("'%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)
+ pr_err("%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
+ pr_err("%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 a 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;
+ s = strreplace(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, const 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 */
+ pr_err("kobject (%p): tried to init an initialized object, something is seriously wrong.\n",
+ kobj);
+ dump_stack_lvl(KERN_ERR);
+ }
+
+ kobject_init_internal(kobj);
+ kobj->ktype = ktype;
+ return;
+
+error:
+ pr_err("kobject (%p): %s\n", kobj, err_str);
+ dump_stack_lvl(KERN_ERR);
+}
+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) {
+ pr_err("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.
+ *
+ * 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.
+ *
+ * Return: 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.
+ *
+ * If this function returns success, kobject_put() must also be called
+ * in order to properly clean up the memory associated with the object.
+ *
+ * In short, once this function is called, kobject_put() MUST be called
+ * when the use of the object is finished in order to properly free
+ * everything.
+ */
+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) {
+ pr_err("kobject '%s' (%p): tried to add an uninitialized object, something is seriously wrong.\n",
+ kobject_name(kobj), kobj);
+ dump_stack_lvl(KERN_ERR);
+ 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().
+ *
+ * If this function returns an error, kobject_put() must be called to
+ * properly clean up the memory associated with the object. This is 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, const 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) {
+ kobject_put(kobj);
+ 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);
+
+static void __kobject_del(struct kobject *kobj)
+{
+ struct kernfs_node *sd;
+ const struct kobj_type *ktype;
+
+ sd = kobj->sd;
+ ktype = get_ktype(kobj);
+
+ sysfs_remove_groups(kobj, ktype->default_groups);
+
+ /* 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("'%s' (%p): auto cleanup 'remove' event\n",
+ kobject_name(kobj), kobj);
+ kobject_uevent(kobj, KOBJ_REMOVE);
+ }
+
+ sysfs_remove_dir(kobj);
+ sysfs_put(sd);
+
+ kobj->state_in_sysfs = 0;
+ kobj_kset_leave(kobj);
+ kobj->parent = NULL;
+}
+
+/**
+ * kobject_del() - Unlink kobject from hierarchy.
+ * @kobj: object.
+ *
+ * This is the function that should be called to delete an object
+ * successfully added via kobject_add().
+ */
+void kobject_del(struct kobject *kobj)
+{
+ struct kobject *parent;
+
+ if (!kobj)
+ return;
+
+ parent = kobj->parent;
+ __kobject_del(kobj);
+ kobject_put(parent);
+}
+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 kobject *parent = kobj->parent;
+ const struct kobj_type *t = get_ktype(kobj);
+ const char *name = kobj->name;
+
+ pr_debug("'%s' (%p): %s, parent %p\n",
+ kobject_name(kobj), kobj, __func__, kobj->parent);
+
+ /* remove from sysfs if the caller did not do it */
+ if (kobj->state_in_sysfs) {
+ pr_debug("'%s' (%p): auto cleanup kobject_del\n",
+ kobject_name(kobj), kobj);
+ __kobject_del(kobj);
+ } else {
+ /* avoid dropping the parent reference unnecessarily */
+ parent = NULL;
+ }
+
+ if (t->release) {
+ pr_debug("'%s' (%p): calling ktype release\n",
+ kobject_name(kobj), kobj);
+ t->release(kobj);
+ } else {
+ pr_debug("'%s' (%p): does not have a release() function, it is broken and must be fixed. See Documentation/core-api/kobject.rst.\n",
+ kobject_name(kobj), kobj);
+ }
+
+ /* free name if we allocated it */
+ if (name) {
+ pr_debug("'%s': free name\n", name);
+ kfree_const(name);
+ }
+
+ kobject_put(parent);
+}
+
+#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_u32_below(4);
+ pr_info("'%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("(%p): %s\n", kobj, __func__);
+ kfree(kobj);
+}
+
+static const 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.
+ */
+static 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) {
+ pr_warn("%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.
+ *
+ * NOTE: On error, the kset.kobj.name allocated by() kobj_set_name()
+ * is freed, it can not be used any more.
+ */
+int kset_register(struct kset *k)
+{
+ int err;
+
+ if (!k)
+ return -EINVAL;
+
+ if (!k->kobj.ktype) {
+ pr_err("must have a ktype to be initialized properly!\n");
+ return -EINVAL;
+ }
+
+ kset_init(k);
+ err = kobject_add_internal(&k->kobj);
+ if (err) {
+ kfree_const(k->kobj.name);
+ /* Set it to NULL to avoid accessing bad pointer in callers. */
+ k->kobj.name = NULL;
+ 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("'%s' (%p): %s\n",
+ kobject_name(kobj), kobj, __func__);
+ kfree(kset);
+}
+
+static void kset_get_ownership(const struct kobject *kobj, kuid_t *uid, kgid_t *gid)
+{
+ if (kobj->parent)
+ kobject_get_ownership(kobj->parent, uid, gid);
+}
+
+static const struct kobj_type kset_ktype = {
+ .sysfs_ops = &kobj_sysfs_ops,
+ .release = kset_release,
+ .get_ownership = kset_get_ownership,
+};
+
+/**
+ * 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 (!kobj_ns_type_is_valid(type))
+ 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 (kobj_ns_type_is_valid(type))
+ 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(const 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(const 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 (kobj_ns_type_is_valid(type) && 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 (kobj_ns_type_is_valid(type) && kobj_ns_ops_tbl[type])
+ ns = kobj_ns_ops_tbl[type]->grab_current_ns();
+ spin_unlock(&kobj_ns_type_lock);
+
+ return ns;
+}
+EXPORT_SYMBOL_GPL(kobj_ns_grab_current);
+
+const void *kobj_ns_netlink(enum kobj_ns_type type, struct sock *sk)
+{
+ const void *ns = NULL;
+
+ spin_lock(&kobj_ns_type_lock);
+ if (kobj_ns_type_is_valid(type) && 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 (kobj_ns_type_is_valid(type) && 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 (kobj_ns_type_is_valid(type) &&
+ 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_GPL(kobj_ns_drop);