From 7d90e81a2d5edbd04037100bdd54d955bdd9b0d0 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Fri, 31 Mar 2023 11:33:12 +0200 Subject: [PATCH] driver core: core: move to use class_to_subsys() There are a number of places in core.c that need access to the private subsystem structure of struct class, so move them to use class_to_subsys() instead of accessing it directly. This requires exporting class_to_subsys() out of class.c, but keeping it local to the driver core. Reviewed-by: Rafael J. Wysocki Link: https://lore.kernel.org/r/20230331093318.82288-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman --- drivers/base/base.h | 2 + drivers/base/class.c | 2 +- drivers/base/core.c | 121 +++++++++++++++++++++++++++++++++------------------ 3 files changed, 81 insertions(+), 44 deletions(-) diff --git a/drivers/base/base.h b/drivers/base/base.h index 2867ca4..6296164 100644 --- a/drivers/base/base.h +++ b/drivers/base/base.h @@ -73,6 +73,8 @@ static inline void subsys_put(struct subsys_private *sp) kset_put(&sp->subsys); } +struct subsys_private *class_to_subsys(const struct class *class); + struct driver_private { struct kobject kobj; struct klist klist_devices; diff --git a/drivers/base/class.c b/drivers/base/class.c index 1f12bd5..68a6f9b 100644 --- a/drivers/base/class.c +++ b/drivers/base/class.c @@ -39,7 +39,7 @@ static struct kset *class_kset; * NULL. A call to subsys_put() must be done when finished with the pointer in * order for it to be properly freed. */ -static struct subsys_private *class_to_subsys(const struct class *class) +struct subsys_private *class_to_subsys(const struct class *class) { struct subsys_private *sp = NULL; struct kobject *kobj; diff --git a/drivers/base/core.c b/drivers/base/core.c index 89249be..e3bc34f 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -3149,8 +3149,8 @@ static const struct kobj_type class_dir_ktype = { .child_ns_type = class_dir_child_ns_type }; -static struct kobject * -class_dir_create_and_add(const struct class *class, struct kobject *parent_kobj) +static struct kobject *class_dir_create_and_add(struct subsys_private *sp, + struct kobject *parent_kobj) { struct class_dir *dir; int retval; @@ -3159,12 +3159,12 @@ class_dir_create_and_add(const struct class *class, struct kobject *parent_kobj) if (!dir) return ERR_PTR(-ENOMEM); - dir->class = class; + dir->class = sp->class; kobject_init(&dir->kobj, &class_dir_ktype); - dir->kobj.kset = &class->p->glue_dirs; + dir->kobj.kset = &sp->glue_dirs; - retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name); + retval = kobject_add(&dir->kobj, parent_kobj, "%s", sp->class->name); if (retval < 0) { kobject_put(&dir->kobj); return ERR_PTR(retval); @@ -3177,9 +3177,10 @@ static DEFINE_MUTEX(gdp_mutex); static struct kobject *get_device_parent(struct device *dev, struct device *parent) { + struct subsys_private *sp = class_to_subsys(dev->class); struct kobject *kobj = NULL; - if (dev->class) { + if (sp) { struct kobject *parent_kobj; struct kobject *k; @@ -3190,30 +3191,34 @@ static struct kobject *get_device_parent(struct device *dev, */ if (parent == NULL) parent_kobj = virtual_device_parent(dev); - else if (parent->class && !dev->class->ns_type) + else if (parent->class && !dev->class->ns_type) { + subsys_put(sp); return &parent->kobj; - else + } else { parent_kobj = &parent->kobj; + } mutex_lock(&gdp_mutex); /* find our class-directory at the parent and reference it */ - spin_lock(&dev->class->p->glue_dirs.list_lock); - list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry) + spin_lock(&sp->glue_dirs.list_lock); + list_for_each_entry(k, &sp->glue_dirs.list, entry) if (k->parent == parent_kobj) { kobj = kobject_get(k); break; } - spin_unlock(&dev->class->p->glue_dirs.list_lock); + spin_unlock(&sp->glue_dirs.list_lock); if (kobj) { mutex_unlock(&gdp_mutex); + subsys_put(sp); return kobj; } /* or create a new class-directory at the parent device */ - k = class_dir_create_and_add(dev->class, parent_kobj); + k = class_dir_create_and_add(sp, parent_kobj); /* do not emit an uevent for this simple "glue" directory */ mutex_unlock(&gdp_mutex); + subsys_put(sp); return k; } @@ -3236,10 +3241,23 @@ static struct kobject *get_device_parent(struct device *dev, static inline bool live_in_glue_dir(struct kobject *kobj, struct device *dev) { - if (!kobj || !dev->class || - kobj->kset != &dev->class->p->glue_dirs) + struct subsys_private *sp; + bool retval; + + if (!kobj || !dev->class) return false; - return true; + + sp = class_to_subsys(dev->class); + if (!sp) + return false; + + if (kobj->kset == &sp->glue_dirs) + retval = true; + else + retval = false; + + subsys_put(sp); + return retval; } static inline struct kobject *get_glue_dir(struct device *dev) @@ -3336,6 +3354,7 @@ static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir) static int device_add_class_symlinks(struct device *dev) { struct device_node *of_node = dev_of_node(dev); + struct subsys_private *sp; int error; if (of_node) { @@ -3345,12 +3364,11 @@ static int device_add_class_symlinks(struct device *dev) /* An error here doesn't warrant bringing down the device */ } - if (!dev->class) + sp = class_to_subsys(dev->class); + if (!sp) return 0; - error = sysfs_create_link(&dev->kobj, - &dev->class->p->subsys.kobj, - "subsystem"); + error = sysfs_create_link(&dev->kobj, &sp->subsys.kobj, "subsystem"); if (error) goto out_devnode; @@ -3362,35 +3380,37 @@ static int device_add_class_symlinks(struct device *dev) } /* link in the class directory pointing to the device */ - error = sysfs_create_link(&dev->class->p->subsys.kobj, - &dev->kobj, dev_name(dev)); + error = sysfs_create_link(&sp->subsys.kobj, &dev->kobj, dev_name(dev)); if (error) goto out_device; - - return 0; + goto exit; out_device: sysfs_remove_link(&dev->kobj, "device"); - out_subsys: sysfs_remove_link(&dev->kobj, "subsystem"); out_devnode: sysfs_remove_link(&dev->kobj, "of_node"); +exit: + subsys_put(sp); return error; } static void device_remove_class_symlinks(struct device *dev) { + struct subsys_private *sp = class_to_subsys(dev->class); + if (dev_of_node(dev)) sysfs_remove_link(&dev->kobj, "of_node"); - if (!dev->class) + if (!sp) return; if (dev->parent && device_is_not_partition(dev)) sysfs_remove_link(&dev->kobj, "device"); sysfs_remove_link(&dev->kobj, "subsystem"); - sysfs_delete_link(&dev->class->p->subsys.kobj, &dev->kobj, dev_name(dev)); + sysfs_delete_link(&sp->subsys.kobj, &dev->kobj, dev_name(dev)); + subsys_put(sp); } /** @@ -3499,6 +3519,7 @@ static int device_private_init(struct device *dev) */ int device_add(struct device *dev) { + struct subsys_private *sp; struct device *parent; struct kobject *kobj; struct class_interface *class_intf; @@ -3627,18 +3648,18 @@ int device_add(struct device *dev) klist_add_tail(&dev->p->knode_parent, &parent->p->klist_children); - if (dev->class) { - mutex_lock(&dev->class->p->mutex); + sp = class_to_subsys(dev->class); + if (sp) { + mutex_lock(&sp->mutex); /* tie the class to the device */ - klist_add_tail(&dev->p->knode_class, - &dev->class->p->klist_devices); + klist_add_tail(&dev->p->knode_class, &sp->klist_devices); /* notify any interfaces that the device is here */ - list_for_each_entry(class_intf, - &dev->class->p->interfaces, node) + list_for_each_entry(class_intf, &sp->interfaces, node) if (class_intf->add_dev) class_intf->add_dev(dev, class_intf); - mutex_unlock(&dev->class->p->mutex); + mutex_unlock(&sp->mutex); + subsys_put(sp); } done: put_device(dev); @@ -3758,6 +3779,7 @@ EXPORT_SYMBOL_GPL(kill_device); */ void device_del(struct device *dev) { + struct subsys_private *sp; struct device *parent = dev->parent; struct kobject *glue_dir = NULL; struct class_interface *class_intf; @@ -3784,18 +3806,20 @@ void device_del(struct device *dev) device_remove_sys_dev_entry(dev); device_remove_file(dev, &dev_attr_dev); } - if (dev->class) { + + sp = class_to_subsys(dev->class); + if (sp) { device_remove_class_symlinks(dev); - mutex_lock(&dev->class->p->mutex); + mutex_lock(&sp->mutex); /* notify any interfaces that the device is now gone */ - list_for_each_entry(class_intf, - &dev->class->p->interfaces, node) + list_for_each_entry(class_intf, &sp->interfaces, node) if (class_intf->remove_dev) class_intf->remove_dev(dev, class_intf); /* remove the device from the class list */ klist_del(&dev->p->knode_class); - mutex_unlock(&dev->class->p->mutex); + mutex_unlock(&sp->mutex); + subsys_put(sp); } device_remove_file(dev, &dev_attr_uevent); device_remove_attrs(dev); @@ -4458,9 +4482,16 @@ int device_rename(struct device *dev, const char *new_name) } if (dev->class) { - error = sysfs_rename_link_ns(&dev->class->p->subsys.kobj, - kobj, old_device_name, + struct subsys_private *sp = class_to_subsys(dev->class); + + if (!sp) { + error = -EINVAL; + goto out; + } + + error = sysfs_rename_link_ns(&sp->subsys.kobj, kobj, old_device_name, new_name, kobject_namespace(kobj)); + subsys_put(sp); if (error) goto out; } @@ -4643,6 +4674,7 @@ int device_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid) { int error; struct kobject *kobj = &dev->kobj; + struct subsys_private *sp; dev = get_device(dev); if (!dev) @@ -4685,10 +4717,13 @@ int device_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid) * directory entry for @dev to @kuid/@kgid. This ensures that the * symlink shows the same permissions as its target. */ - error = sysfs_link_change_owner(&dev->class->p->subsys.kobj, &dev->kobj, - dev_name(dev), kuid, kgid); - if (error) + sp = class_to_subsys(dev->class); + if (!sp) { + error = -EINVAL; goto out; + } + error = sysfs_link_change_owner(&sp->subsys.kobj, &dev->kobj, dev_name(dev), kuid, kgid); + subsys_put(sp); out: put_device(dev); -- 2.7.4