Re: [PATCH 4.4 3/3] futex: fix dead code in attach_to_pi_owner()

[Greg KH]

On Tue, Mar 09, 2021 at 11:06:05AM +0800, Zheng Yejian wrote:
> From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> 
> The handle_exit_race() function is defined in commit 9c3f39860367
>  ("futex: Cure exit race"), which never returns -EBUSY. This results
> in a small piece of dead code in the attach_to_pi_owner() function:
> 
> 	int ret = handle_exit_race(uaddr, uval, p); /* Never return -EBUSY */
> 	...
> 	if (ret == -EBUSY)
> 		*exiting = p; /* dead code */
> 
> The return value -EBUSY is added to handle_exit_race() in upsteam
> commit ac31c7ff8624409 ("futex: Provide distinct return value when
> owner is exiting"). This commit was incorporated into v4.9.255, before
> the function handle_exit_race() was introduced, whitout Modify
> handle_exit_race().
> 
> To fix dead code, extract the change of handle_exit_race() from
> commit ac31c7ff8624409 ("futex: Provide distinct return value when owner
>  is exiting"), re-incorporated.
> 
> Lee writes:
> 
> This commit takes the remaining functional snippet of:
> 
>  ac31c7ff8624409 ("futex: Provide distinct return value when owner is exiting")
> 
> ... and is the correct fix for this issue.
> 
> Fixes: 9c3f39860367 ("futex: Cure exit race")
> Cc: stable@xxxxxxxxxxxxxxx # v4.9.258
> Signed-off-by: Xiaoming Ni <nixiaoming@xxxxxxxxxx>
> Reviewed-by: Lee Jones <lee.jones@xxxxxxxxxx>
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Zheng Yejian <zhengyejian1@xxxxxxxxxx>
> ---
>  kernel/futex.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)

Same here, what is the upstream git id?

thanks,

greg k-h