2020-06-24 18:39:20

by Christian Borntraeger

Subject: Re: linux-next: umh: fix processed error when UMH_WAIT_PROC is used seems to break linux bridge on s390x (bisected)

On 24.06.20 20:32, Christian Borntraeger wrote:
[...]>
> So the translations look correct. But your change is actually a sematic change
> if(ret) will only trigger if there is an error
> if (KWIFEXITED(ret)) will always trigger when the process ends. So we will always overwrite -ECHILD
> and we did not do it before.
>

So the right fix is

diff --git a/kernel/umh.c b/kernel/umh.c
index f81e8698e36e..a3a3196e84d1 100644
--- a/kernel/umh.c
+++ b/kernel/umh.c
@@ -154,7 +154,7 @@ static void call_usermodehelper_exec_sync(struct subprocess_info *sub_info)
* the real error code is already in sub_info->retval or
* sub_info->retval is 0 anyway, so don't mess with it then.
*/
- if (KWIFEXITED(ret))
+ if (KWEXITSTATUS(ret))
sub_info->retval = KWEXITSTATUS(ret);
}



I think.

2020-06-25 13:28:25

by Christian Borntraeger

Subject: Re: linux-next: umh: fix processed error when UMH_WAIT_PROC is used seems to break linux bridge on s390x (bisected)

On 24.06.20 20:37, Christian Borntraeger wrote:
>
>
> On 24.06.20 20:32, Christian Borntraeger wrote:
> [...]>
>> So the translations look correct. But your change is actually a sematic change
>> if(ret) will only trigger if there is an error
>> if (KWIFEXITED(ret)) will always trigger when the process ends. So we will always overwrite -ECHILD
>> and we did not do it before.
>>
>
> So the right fix is
>
> diff --git a/kernel/umh.c b/kernel/umh.c
> index f81e8698e36e..a3a3196e84d1 100644
> --- a/kernel/umh.c
> +++ b/kernel/umh.c
> @@ -154,7 +154,7 @@ static void call_usermodehelper_exec_sync(struct subprocess_info *sub_info)
> * the real error code is already in sub_info->retval or
> * sub_info->retval is 0 anyway, so don't mess with it then.
> */
> - if (KWIFEXITED(ret))
> + if (KWEXITSTATUS(ret))
> sub_info->retval = KWEXITSTATUS(ret);
> }

Ping. Shall I send this as a proper patch or are we merging this fixup in Andrews patch queue?