[prev in list] [next in list] [prev in thread] [next in thread] 

List:       kde-frameworks-devel
Subject:    Re: Review Request 128790: Remove usage of utempter
From:       Martin Tobias Holmedahl Sandsmark <martin.sandsmark () kde ! org>
Date:       2016-08-28 13:52:14
Message-ID: 20160828135214.27514.85353 () mimi ! kde ! org
[Download RAW message or body]

--===============3297393490186748167==
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 7bit



> On Aug. 28, 2016, 1:41 p.m., Oswald Buddenhagen wrote:
> > uhm, and why do you think utempter is the preferred choice?
> > last time i checked, nobody was shipping konsole setgid utmp. with kdeinit, \
> > that's not even an option. 
> > there are several options how to deal with this:
> > - fork()/wait() around the utempter calls, so it can't mess with the signal \
> > handling of the current process. though i seem to remmber that the addToUtmp() \
> >                 call actually uses the PID
> > - re-implement the libutempter calls with QProcess. that's actually how it was \
> > originally, but was changed because there were incompatible versions of utempter \
> >                 - but that seems like a minor concern compared to the status quo.
> > - drop utmp handling altogether, as it's been mostly superseded, first by \
> > consolekit, and now logind. however, respective bindings would have to be \
> > actually implemented, and i have no clue how things are supposed to be done. just \
> >                 some dbus calls?
> > -- what about non-linux systems?

> uhm, and why do you think utempter is the preferred choice?
> last time i checked, nobody was shipping konsole setgid utmp. with kdeinit, that's \
> not even an option.

Why is the fallback code there at all, then?


> - fork()/wait() around the utempter calls, so it can't mess with the signal \
> handling of the current process. though i seem to remmber that the addToUtmp() call \
> actually uses the PID

Won't that break if another process exits at the wrong time?


> - re-implement the libutempter calls with QProcess. that's actually how it was \
> originally, but was changed because there were incompatible versions of utempter - \
> but that seems like a minor concern compared to the status quo.

I looked at that as well, the issue is finding the correct path for the utempter \
helper.

 
> - drop utmp handling altogether, as it's been mostly superseded, first by \
> consolekit, and now logind. however, respective bindings would have to be actually \
> implemented, and i have no clue how things are supposed to be done. just some dbus \
> calls?

There seems to be a simple dbus call to register with logind at least. I tried \
looking briefly at it, but I couldn't quickly find any logind code that did utmp \
stuff. I didn't look very hard, though.


> -- what about non-linux systems?

libutempter only supports Linux and FreeBSD, the fallback code seems to at least try \
to be compatible with other platforms.


- Martin Tobias Holmedahl


-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
https://git.reviewboard.kde.org/r/128790/#review98742
-----------------------------------------------------------


On Aug. 28, 2016, 1:13 p.m., Martin Tobias Holmedahl Sandsmark wrote:
> 
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> https://git.reviewboard.kde.org/r/128790/
> -----------------------------------------------------------
> 
> (Updated Aug. 28, 2016, 1:13 p.m.)
> 
> 
> Review request for KDE Frameworks, David Faure, Kurt Hindenburg, Rex Dieter, and \
> Thiago Macieira. 
> 
> Bugs: 364779
> https://bugs.kde.org/show_bug.cgi?id=364779
> 
> 
> Repository: kpty
> 
> 
> Description
> -------
> 
> According to the investigation in https://bugs.kde.org/show_bug.cgi?id=364779 \
> utempter does stuff in a way that isn't compatible with \
> QProcess/KProcess/KPtyProcess (calling sigaction() before launching its child \
> process). So remove it, and rely on the fallback methods already implemented. 
> 
> Diffs
> -----
> 
> CMakeLists.txt 3e17cac 
> KF5PtyConfig.cmake.in 66f8c43 
> cmake/FindUTEMPTER.cmake a3ea06a 
> src/CMakeLists.txt caab96f 
> src/ConfigureChecks.cmake ded08f4 
> src/config-pty.h.cmake aaaf8d9 
> src/kpty.cpp 15c3b81 
> 
> Diff: https://git.reviewboard.kde.org/r/128790/diff/
> 
> 
> Testing
> -------
> 
> 
> Thanks,
> 
> Martin Tobias Holmedahl Sandsmark
> 
> 


--===============3297393490186748167==
MIME-Version: 1.0
Content-Type: text/html; charset="utf-8"
Content-Transfer-Encoding: 7bit




<html>
 <body>
  <div style="font-family: Verdana, Arial, Helvetica, Sans-Serif;">
   <table bgcolor="#f9f3c9" width="100%" cellpadding="12" style="border: 1px #c9c399 \
solid; border-radius: 6px; -moz-border-radius: 6px; -webkit-border-radius: 6px;">  \
<tr>  <td>
      This is an automatically generated e-mail. To reply, visit:
      <a href="https://git.reviewboard.kde.org/r/128790/">https://git.reviewboard.kde.org/r/128790/</a>
  </td>
    </tr>
   </table>
   <br />





<blockquote style="margin-left: 1em; border-left: 2px solid #d0d0d0; padding-left: \
10px;">  <p style="margin-top: 0;">On August 28th, 2016, 1:41 p.m. UTC, <b>Oswald \
Buddenhagen</b> wrote:</p>  <blockquote style="margin-left: 1em; border-left: 2px \
solid #d0d0d0; padding-left: 10px;">  <pre style="white-space: pre-wrap; white-space: \
-moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: \
break-word;"><p style="padding: 0;text-rendering: inherit;margin: 0;line-height: \
inherit;white-space: inherit;">uhm, and why do you think utempter is the preferred \
choice? last time i checked, nobody was shipping konsole setgid utmp. with kdeinit, \
that's not even an option.</p> <p style="padding: 0;text-rendering: inherit;margin: \
0;line-height: inherit;white-space: inherit;">there are several options how to deal \
                with this:
- fork()/wait() around the utempter calls, so it can't mess with the signal handling \
of the current process. though i seem to remmber that the addToUtmp() call actually \
                uses the PID
- re-implement the libutempter calls with QProcess. that's actually how it was \
originally, but was changed because there were incompatible versions of utempter - \
                but that seems like a minor concern compared to the status quo.
- drop utmp handling altogether, as it's been mostly superseded, first by consolekit, \
and now logind. however, respective bindings would have to be actually implemented, \
                and i have no clue how things are supposed to be done. just some dbus \
                calls?
-- what about non-linux systems?</p></pre>
 </blockquote>







</blockquote>

<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: \
-pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;"><blockquote \
style="text-rendering: inherit;padding: 0 0 0 1em;border-left: 1px solid \
#bbb;white-space: normal;margin: 0 0 0 0.5em;line-height: inherit;"> <p \
style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: \
inherit;">uhm, and why do you think utempter is the preferred choice? last time i \
checked, nobody was shipping konsole setgid utmp. with kdeinit, that's not even an \
option.</p> </blockquote>
<p style="padding: 0;text-rendering: inherit;margin: 0;line-height: \
inherit;white-space: inherit;">Why is the fallback code there at all, then?</p> \
<blockquote style="text-rendering: inherit;padding: 0 0 0 1em;border-left: 1px solid \
#bbb;white-space: normal;margin: 0 0 0 0.5em;line-height: inherit;"> <ul \
style="padding: 0;text-rendering: inherit;margin: 0 0 0 1em;line-height: \
inherit;white-space: normal;"> <li style="padding: 0;text-rendering: inherit;margin: \
0;line-height: inherit;white-space: normal;">fork()/wait() around the utempter calls, \
so it can't mess with the signal handling of the current process. though i seem to \
remmber that the addToUtmp() call actually uses the PID</li> </ul>
</blockquote>
<p style="padding: 0;text-rendering: inherit;margin: 0;line-height: \
inherit;white-space: inherit;">Won't that break if another process exits at the wrong \
time?</p> <blockquote style="text-rendering: inherit;padding: 0 0 0 1em;border-left: \
1px solid #bbb;white-space: normal;margin: 0 0 0 0.5em;line-height: inherit;"> <ul \
style="padding: 0;text-rendering: inherit;margin: 0 0 0 1em;line-height: \
inherit;white-space: normal;"> <li style="padding: 0;text-rendering: inherit;margin: \
0;line-height: inherit;white-space: normal;">re-implement the libutempter calls with \
QProcess. that's actually how it was originally, but was changed because there were \
incompatible versions of utempter - but that seems like a minor concern compared to \
the status quo.</li> </ul>
</blockquote>
<p style="padding: 0;text-rendering: inherit;margin: 0;line-height: \
inherit;white-space: inherit;">I looked at that as well, the issue is finding the \
correct path for the utempter helper.</p> <blockquote style="text-rendering: \
inherit;padding: 0 0 0 1em;border-left: 1px solid #bbb;white-space: normal;margin: 0 \
0 0 0.5em;line-height: inherit;"> <ul style="padding: 0;text-rendering: \
inherit;margin: 0 0 0 1em;line-height: inherit;white-space: normal;"> <li \
style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: \
normal;">drop utmp handling altogether, as it's been mostly superseded, first by \
consolekit, and now logind. however, respective bindings would have to be actually \
implemented, and i have no clue how things are supposed to be done. just some dbus \
calls?</li> </ul>
</blockquote>
<p style="padding: 0;text-rendering: inherit;margin: 0;line-height: \
inherit;white-space: inherit;">There seems to be a simple dbus call to register with \
logind at least. I tried looking briefly at it, but I couldn't quickly find any \
logind code that did utmp stuff. I didn't look very hard, though.</p> <blockquote \
style="text-rendering: inherit;padding: 0 0 0 1em;border-left: 1px solid \
#bbb;white-space: normal;margin: 0 0 0 0.5em;line-height: inherit;"> <p \
style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: \
inherit;">-- what about non-linux systems?</p> </blockquote>
<p style="padding: 0;text-rendering: inherit;margin: 0;line-height: \
inherit;white-space: inherit;">libutempter only supports Linux and FreeBSD, the \
fallback code seems to at least try to be compatible with other platforms.</p></pre> \
<br />










<p>- Martin Tobias Holmedahl</p>


<br />
<p>On August 28th, 2016, 1:13 p.m. UTC, Martin Tobias Holmedahl Sandsmark wrote:</p>








<table bgcolor="#fefadf" width="100%" cellspacing="0" cellpadding="12" style="border: \
1px #888a85 solid; border-radius: 6px; -moz-border-radius: 6px; \
-webkit-border-radius: 6px;">  <tr>
  <td>

<div>Review request for KDE Frameworks, David Faure, Kurt Hindenburg, Rex Dieter, and \
Thiago Macieira.</div> <div>By Martin Tobias Holmedahl Sandsmark.</div>


<p style="color: grey;"><i>Updated Aug. 28, 2016, 1:13 p.m.</i></p>







<div style="margin-top: 1.5em;">
 <b style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Bugs: </b>


 <a href="https://bugs.kde.org/show_bug.cgi?id=364779">364779</a>


</div>



<div style="margin-top: 1.5em;">
 <b style="color: #575012; font-size: 10pt;">Repository: </b>
kpty
</div>


<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Description </h1>
 <table width="100%" bgcolor="#ffffff" cellspacing="0" cellpadding="10" \
style="border: 1px solid #b8b5a0">  <tr>
  <td>
   <pre style="margin: 0; padding: 0; white-space: pre-wrap; white-space: \
-moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: \
break-word;"><p style="padding: 0;text-rendering: inherit;margin: 0;line-height: \
inherit;white-space: inherit;">According to the investigation in \
https://bugs.kde.org/show_bug.cgi?id=364779 utempter does stuff in a way that isn't \
compatible with QProcess/KProcess/KPtyProcess (calling sigaction() before launching \
its child process). So remove it, and rely on the fallback methods already \
implemented.</p></pre>  </td>
 </tr>
</table>



<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Diffs</b> </h1>
<ul style="margin-left: 3em; padding-left: 0;">

 <li>CMakeLists.txt <span style="color: grey">(3e17cac)</span></li>

 <li>KF5PtyConfig.cmake.in <span style="color: grey">(66f8c43)</span></li>

 <li>cmake/FindUTEMPTER.cmake <span style="color: grey">(a3ea06a)</span></li>

 <li>src/CMakeLists.txt <span style="color: grey">(caab96f)</span></li>

 <li>src/ConfigureChecks.cmake <span style="color: grey">(ded08f4)</span></li>

 <li>src/config-pty.h.cmake <span style="color: grey">(aaaf8d9)</span></li>

 <li>src/kpty.cpp <span style="color: grey">(15c3b81)</span></li>

</ul>

<p><a href="https://git.reviewboard.kde.org/r/128790/diff/" style="margin-left: \
3em;">View Diff</a></p>






  </td>
 </tr>
</table>







  </div>
 </body>
</html>


--===============3297393490186748167==--


[prev in list] [next in list] [prev in thread] [next in thread] 

Configure | About | News | Add a list | Sponsored by KoreLogic