Re: [PATCH v2 1/2] ext4: Forcing subclasses to have same name pointer as their parent class

[Waiman Long <longman@redhat.com>]

On 7/14/24 01:14, botta633 wrote:
> From: Ahmed Ehab <bottaawesome633@gmail.com>
>
> Preventing lockdep_set_subclass from creating a new instance of the
> string literal. Hence, we will always have the same class->name among
> parent and subclasses. This prevents kernel panics when looking up a
> lock class while comparing class locks and class names.
>
> Reported-by: <syzbot+7f4a6f7f7051474e40ad@syzkaller.appspotmail.com>
> Fixes: fd5e3f5fe27
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Ahmed Ehab <bottaawesome633@gmail.com>
> ---
>   include/linux/lockdep.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
> index 08b0d1d9d78b..df8fa5929de7 100644
> --- a/include/linux/lockdep.h
> +++ b/include/linux/lockdep.h
> @@ -173,7 +173,7 @@ static inline void lockdep_init_map(struct lockdep_map *lock, const char *name,
>   			      (lock)->dep_map.lock_type)
>   
>   #define lockdep_set_subclass(lock, sub)					\
> -	lockdep_init_map_type(&(lock)->dep_map, #lock, (lock)->dep_map.key, sub,\
> +	lockdep_init_map_type(&(lock)->dep_map, (lock)->dep_map.name, (lock)->dep_map.key, sub,\
>   			      (lock)->dep_map.wait_type_inner,		\
>   			      (lock)->dep_map.wait_type_outer,		\
>   			      (lock)->dep_map.lock_type)

ext4 is a filesystem. It has nothing to do with locking/lockdep. Could 
you resend the patches with the proper prefix of "lockdep:" or 
"locking/lockdep:"?

Thanks,
Longman