From ee6d3dd4ed48ab24b74bab3c3977b8218518247d Mon Sep 17 00:00:00 2001 From: Wedson Almeida Filho Date: Fri, 24 Dec 2021 23:13:45 +0000 Subject: [PATCH] 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: Wedson Almeida Filho Link: https://lore.kernel.org/r/20211224231345.777370-1-wedsonaf@google.com Signed-off-by: Greg Kroah-Hartman --- 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",