Commit 87ac7d79 authored by George Stark's avatar George Stark Committed by Tengda Wu
Browse files

locking/mutex: Introduce devm_mutex_init() 

mainline inclusion
from mainline-v6.10-rc1
commit 4cd47222e435dec8e3787614924174f53fcfb5ae
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAGS4V
CVE: CVE-2024-42129

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=4cd47222e435dec8e3787614924174f53fcfb5ae



--------------------------------

Using of devm API leads to a certain order of releasing resources.
So all dependent resources which are not devm-wrapped should be deleted
with respect to devm-release order. Mutex is one of such objects that
often is bound to other resources and has no own devm wrapping.
Since mutex_destroy() actually does nothing in non-debug builds
frequently calling mutex_destroy() is just ignored which is safe for now
but wrong formally and can lead to a problem if mutex_destroy() will be
extended so introduce devm_mutex_init().

Suggested-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: default avatarGeorge Stark <gnstark@salutedevices.com>
Reviewed-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: default avatarMarek Behún <kabel@kernel.org>
Acked-by: default avatarWaiman Long <longman@redhat.com>
Link: https://lore.kernel.org/r/20240411161032.609544-2-gnstark@salutedevices.com


Signed-off-by: default avatarLee Jones <lee@kernel.org>

Conflicts:
	include/linux/mutex.h
[The commit bb630f9f ("locking/rtmutex: Add mutex variant for RT") has
nothing to do with this patch, so skip backporting]
Signed-off-by: default avatarTengda Wu <wutengda2@huawei.com>
parent 03b9074c

include/linux/mutex.h

+27 −0
Original line number Diff line number Diff line
@@ -20,6 +20,8 @@ 
#include <linux/osq_lock.h>

#include <linux/debug_locks.h>



struct device;



struct ww_acquire_ctx;



/*
@@ -150,6 +152,31 @@ extern void __mutex_init(struct mutex *lock, const char *name, 
 */

extern bool mutex_is_locked(struct mutex *lock);



#ifdef CONFIG_DEBUG_MUTEXES



int __devm_mutex_init(struct device *dev, struct mutex *lock);



#else



static inline int __devm_mutex_init(struct device *dev, struct mutex *lock)

{

	/*

	 * When CONFIG_DEBUG_MUTEXES is off mutex_destroy() is just a nop so

	 * no really need to register it in the devm subsystem.

	 */

	return 0;

}



#endif



#define devm_mutex_init(dev, mutex)			\

({							\

	typeof(mutex) mutex_ = (mutex);			\

							\

	mutex_init(mutex_);				\

	__devm_mutex_init(dev, mutex_);			\

})



/*

 * See kernel/locking/mutex.c for detailed documentation of these APIs.

 * Also see Documentation/locking/mutex-design.rst.

kernel/locking/mutex-debug.c

+12 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
 */

#include <linux/mutex.h>

#include <linux/delay.h>

#include <linux/device.h>

#include <linux/export.h>

#include <linux/poison.h>

#include <linux/sched.h>
@@ -90,6 +91,17 @@ void debug_mutex_init(struct mutex *lock, const char *name, 
	lock->magic = lock;

}



static void devm_mutex_release(void *res)

{

	mutex_destroy(res);

}



int __devm_mutex_init(struct device *dev, struct mutex *lock)

{

	return devm_add_action_or_reset(dev, devm_mutex_release, lock);

}

EXPORT_SYMBOL_GPL(__devm_mutex_init);



/***

 * mutex_destroy - mark a mutex unusable

 * @lock: the mutex to be destroyed