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Subject[PATCH] driver core: make kobj_type constant.
From
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: Wedson Almeida Filho <wedsonaf@google.com>
---
Documentation/core-api/kobject.rst | 4 ++--
drivers/base/bus.c | 2 +-
drivers/base/core.c | 2 +-
include/linux/kobject.h | 8 ++++----
kernel/params.c | 2 +-
lib/kobject.c | 8 ++++----
6 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/Documentation/core-api/kobject.rst b/Documentation/core-api/kobject.rst
index 2739f8b72575..d3b5bf9f643a 100644
--- a/Documentation/core-api/kobject.rst
+++ b/Documentation/core-api/kobject.rst
@@ -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
diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index bdc98c5713d5..a64454f5f8c0 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -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;
diff --git a/drivers/base/core.c b/drivers/base/core.c
index fd034d742447..d712ea11066b 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -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);
diff --git a/include/linux/kobject.h b/include/linux/kobject.h
index c740062b4b1a..683172b2e094 100644
--- a/include/linux/kobject.h
+++ b/include/linux/kobject.h
@@ -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;
}
diff --git a/kernel/params.c b/kernel/params.c
index 8299bd764e42..9b90e3c4d3c0 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -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;
diff --git a/lib/kobject.c b/lib/kobject.c
index 4a56f519139d..56fa037501b5 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -65,7 +65,7 @@ void kobject_get_ownership(struct kobject *kobj, kuid_t *uid, kgid_t *gid)
*/
static int populate_dir(struct kobject *kobj)
{
- struct kobj_type *t = get_ktype(kobj);
+ const struct kobj_type *t = get_ktype(kobj);
struct attribute *attr;
int error = 0;
int i;
@@ -346,7 +346,7 @@ EXPORT_SYMBOL(kobject_set_name);
* 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)
+void kobject_init(struct kobject *kobj, const struct kobj_type *ktype)
{
char *err_str;

@@ -461,7 +461,7 @@ EXPORT_SYMBOL(kobject_add);
* 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,
+int kobject_init_and_add(struct kobject *kobj, const struct kobj_type *ktype,
struct kobject *parent, const char *fmt, ...)
{
va_list args;
@@ -679,7 +679,7 @@ EXPORT_SYMBOL(kobject_get_unless_zero);
static void kobject_cleanup(struct kobject *kobj)
{
struct kobject *parent = kobj->parent;
- struct kobj_type *t = get_ktype(kobj);
+ const struct kobj_type *t = get_ktype(kobj);
const char *name = kobj->name;

pr_debug("kobject: '%s' (%p): %s, parent %p\n",
--
2.34.1.448.ga2b2bfdf31-goog
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