# Re: \[GIT PULL\] namespaces related fixes for v4.11-rc1

- List: linux-api
- 3 messages, 3 authors
- Page: https://ratatoskr.run/linux-api/2017/02/118026/t

## Re: \[GIT PULL\] namespaces related fixes for v4.11-rc1

- From: Eric W. Biederman \<hidden\>
- Date: 2017-02-23 01:35:06 
- Message: https://ratatoskr.run/linux-api/2017/02/118026.md

```text
Aleksa Sarai [ref] writes:

>> The only known user of this prctl systemd
>> forks all children after the prctl.  So no userspace regressions will
>> occur.
>
> Note that runC and containerd (and thus Docker) as well as cri-o use the prctl
> as well -- to be able to collect exit codes from a non-child process (namely to
> collect the exit code from PID 1 in the container).

Are any of those affected by the change?  I would not expect so.  As it
would require having children or grand children whose exit codes you
don't want to collect.

Eric
```

## Re: \[GIT PULL\] namespaces related fixes for v4.11-rc1

- From: Aleksa Sarai \<hidden\>
- Date: 2017-02-23 02:21:42 
- Message: https://ratatoskr.run/linux-api/2017/02/118025.md

```text
>>> The only known user of this prctl systemd
>>> forks all children after the prctl.  So no userspace regressions will
>>> occur.
>>
>> Note that runC and containerd (and thus Docker) as well as cri-o use the prctl
>> as well -- to be able to collect exit codes from a non-child process (namely to
>> collect the exit code from PID 1 in the container).
>
> Are any of those affected by the change?  I would not expect so.  As it
> would require having children or grand children whose exit codes you
> don't want to collect.

AFAICS they do appear to work (and runC definitely calls the prctl before it creates the container init process -- so it shouldn't break anything for runC). I was just pointing out that systemd isn't the only major userspace user of the prctl (for future reference).

-- 
Aleksa Sarai
Software Engineer (Containers)
SUSE Linux GmbH
https://www.cyphar.com/
```

## Re: \[GIT PULL\] namespaces related fixes for v4.11-rc1

- From: Andy Lutomirski \<luto@amacapital.net\>
- Date: 2017-02-23 03:06:39 
- Message: https://ratatoskr.run/linux-api/2017/02/118024.md

```text
On Wed, Feb 22, 2017 at 5:29 PM, Eric W. Biederman
[ref] wrote:
> Aleksa Sarai [ref] writes:
>
>>> The only known user of this prctl systemd
>>> forks all children after the prctl.  So no userspace regressions will
>>> occur.
>>
>> Note that runC and containerd (and thus Docker) as well as cri-o use the prctl
>> as well -- to be able to collect exit codes from a non-child process (namely to
>> collect the exit code from PID 1 in the container).
>
> Are any of those affected by the change?  I would not expect so.  As it
> would require having children or grand children whose exit codes you
> don't want to collect.

FWIW, I have private code that uses PR_SET_CHILD_SUBREAPER, too.  I
don't see why it would be affected by this change.
```