leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

kobject: Make sure the parent does not get released before its children

Browse Source 
In the function kobject_cleanup(), kobject_del(kobj) is
called before the kobj->release(). That makes it possible to
release the parent of the kobject before the kobject itself.

To fix that, adding function __kboject_del() that does
everything that kobject_del() does except release the parent
reference. kobject_cleanup() then calls __kobject_del()
instead of kobject_del(), and separately decrements the
reference count of the parent kobject after kobj->release()
has been called.

Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reported-by: kernel test robot <rong.a.chen@intel.com>
Fixes: 7589238a8c ("Revert "software node: Simplify software_node_release() function"")
Suggested-by: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20200513151840.36400-1-heikki.krogerus@linux.intel.com
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Heikki Krogerus 2020-05-13 18:18:40 +03:00 committed by Greg Kroah-Hartman
parent 44e960490d
commit 4ef12f7198
1 changed files with 20 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
lib/kobject.c
View File

@ -599,14 +599,7 @@ out:
}
EXPORT_SYMBOL_GPL(kobject_move);
/**
* 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)
static void __kobject_del(struct kobject *kobj)
{
struct kernfs_node *sd;
const struct kobj_type *ktype;
@ -625,9 +618,23 @@ void kobject_del(struct kobject *kobj)
kobj->state_in_sysfs = 0;
kobj_kset_leave(kobj);
kobject_put(kobj->parent);
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 = kobj->parent;
__kobject_del(kobj);
kobject_put(parent);
}
EXPORT_SYMBOL(kobject_del);
/**
@ -663,6 +670,7 @@ 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 char *name = kobj->name;
@ -684,7 +692,7 @@ static void kobject_cleanup(struct kobject *kobj)
if (kobj->state_in_sysfs) {
pr_debug("kobject: '%s' (%p): auto cleanup kobject_del\n",
kobject_name(kobj), kobj);
kobject_del(kobj);
__kobject_del(kobj);
}
if (t && t->release) {
@ -698,6 +706,8 @@ static void kobject_cleanup(struct kobject *kobj)
pr_debug("kobject: '%s': free name\n", name);
kfree_const(name);
}
kobject_put(parent);
}
#ifdef CONFIG_DEBUG_KOBJECT_RELEASE