Commit ee6d3dd4 authored by Wedson Almeida Filho's avatar Wedson Almeida Filho Committed by Greg Kroah-Hartman
Browse files

driver core: make kobj_type constant. 



This way instances of kobj_type (which contain function pointers) can be
stored in .rodata, which means that they cannot be [easily/accidentally]
modified at runtime.

Signed-off-by: default avatarWedson Almeida Filho <wedsonaf@google.com>
Link: https://lore.kernel.org/r/20211224231345.777370-1-wedsonaf@google.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 67e532a4

Documentation/core-api/kobject.rst

+2 −2
Original line number Diff line number Diff line
@@ -118,7 +118,7 @@ Initialization of kobjects 
Code which creates a kobject must, of course, initialize that object. Some

of the internal fields are setup with a (mandatory) call to kobject_init()::



    void kobject_init(struct kobject *kobj, struct kobj_type *ktype);

    void kobject_init(struct kobject *kobj, const struct kobj_type *ktype);



The ktype is required for a kobject to be created properly, as every kobject

must have an associated kobj_type.  After calling kobject_init(), to
@@ -156,7 +156,7 @@ kobject_name():: 
There is a helper function to both initialize and add the kobject to the

kernel at the same time, called surprisingly enough kobject_init_and_add()::



    int kobject_init_and_add(struct kobject *kobj, struct kobj_type *ktype,

    int kobject_init_and_add(struct kobject *kobj, const struct kobj_type *ktype,

                             struct kobject *parent, const char *fmt, ...);



The arguments are the same as the individual kobject_init() and

drivers/base/bus.c

+1 −1
Original line number Diff line number Diff line
@@ -165,7 +165,7 @@ static struct kobj_type bus_ktype = { 


static int bus_uevent_filter(struct kset *kset, struct kobject *kobj)

{

	struct kobj_type *ktype = get_ktype(kobj);

	const struct kobj_type *ktype = get_ktype(kobj);



	if (ktype == &bus_ktype)

		return 1;

drivers/base/core.c

+1 −1
Original line number Diff line number Diff line
@@ -2263,7 +2263,7 @@ static struct kobj_type device_ktype = { 


static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)

{

	struct kobj_type *ktype = get_ktype(kobj);

	const struct kobj_type *ktype = get_ktype(kobj);



	if (ktype == &device_ktype) {

		struct device *dev = kobj_to_dev(kobj);

include/linux/kobject.h

+4 −4
Original line number Diff line number Diff line
@@ -66,7 +66,7 @@ struct kobject { 
	struct list_head	entry;

	struct kobject		*parent;

	struct kset		*kset;

	struct kobj_type	*ktype;

	const struct kobj_type	*ktype;

	struct kernfs_node	*sd; /* sysfs directory entry */

	struct kref		kref;

#ifdef CONFIG_DEBUG_KOBJECT_RELEASE
@@ -90,13 +90,13 @@ static inline const char *kobject_name(const struct kobject *kobj) 
	return kobj->name;

}



extern void kobject_init(struct kobject *kobj, struct kobj_type *ktype);

extern void kobject_init(struct kobject *kobj, const struct kobj_type *ktype);

extern __printf(3, 4) __must_check

int kobject_add(struct kobject *kobj, struct kobject *parent,

		const char *fmt, ...);

extern __printf(4, 5) __must_check

int kobject_init_and_add(struct kobject *kobj,

			 struct kobj_type *ktype, struct kobject *parent,

			 const struct kobj_type *ktype, struct kobject *parent,

			 const char *fmt, ...);



extern void kobject_del(struct kobject *kobj);
@@ -217,7 +217,7 @@ static inline void kset_put(struct kset *k) 
	kobject_put(&k->kobj);

}



static inline struct kobj_type *get_ktype(struct kobject *kobj)

static inline const struct kobj_type *get_ktype(struct kobject *kobj)

{

	return kobj->ktype;

}

kernel/params.c

+1 −1
Original line number Diff line number Diff line
@@ -928,7 +928,7 @@ static const struct sysfs_ops module_sysfs_ops = { 


static int uevent_filter(struct kset *kset, struct kobject *kobj)

{

	struct kobj_type *ktype = get_ktype(kobj);

	const struct kobj_type *ktype = get_ktype(kobj);



	if (ktype == &module_ktype)

		return 1;