Re: [PATCH v7 0/6] seccomp trap to userspace

Kees Cook
2018-09-28T22:34:37Z

On Fri, Sep 28, 2018 at 3:16 PM, Michael Kerrisk (man-pages)
<mtk.manpages@gmail.com> wrote:
> Hi Tycho,
>
> On Sat, 29 Sep 2018 at 00:04, Tycho Andersen <tycho@tycho.ws> wrote:
>>
>> On Fri, Sep 28, 2018 at 11:57:40PM +0200, Michael Kerrisk (man-opages) wrote:
>> > Hi Tycho,
>> >
>> > On 09/27/2018 05:11 PM, Tycho Andersen wrote:
>> > > Hi all,
>> > >
>> > > Here's v7 of the seccomp trap to userspace set. There are various minor
>> > > changes and bug fixes, but two major changes:
>> > >
>> > > * We now pass fds to the tracee via an ioctl, and do it immediately when
>> > > the ioctl is called. For this we needed some help from the vfs, so
>> > > I've put the one patch in this series and cc'd fsdevel. This does have
>> > > the advantage that the feature is now totally decoupled from the rest
>> > > of the set, which is itself useful (thanks Andy!)
>> > >
>> > > * Instead of putting all of the notification related stuff into the
>> > > struct seccomp_filter, it now lives in its own struct notification,
>> > > which is pointed to by struct seccomp_filter. This will save a lot of
>> > > memory (thanks Tyler!)
>> >
>> > Is there a documentation (man page) patch for this API change?
>>
>> Not yet, but once we decide on a final API I'll prepare one.
>
> Honestly, the production of such documentation should be part of the
> evolution towards the final API...
>
> Documentation is not an afterthought. It's a tool for pushing you, the
> developer (and others, your reviewers) to more deeply consider your
> design.

In Tycho's defense, he did write up documentation in Documentation/
for the feature, so it won't be an afterthought. :) But yes, there's
no manpage delta yet.

-Kees

--
Kees Cook
Pixel Security