Interesting.  How does setuid have this effect on i3lock but only under
strace?

Any idea where the setuid is coming from or how to find out?  The system is
pretty vanilla ubuntu 14.10 (they have a good installer) aside from running
i3 instead of gnome.

The exec path that's visible once I'm logged in is lightdm -> lightdm
--sesion-child -> i3.  I see that i3 parents what is executed due to
.xsessionrc.

I'll try to gather traces with -p, but this will depend on me thinking to
trace i3lock from a vt before unlocking the screen.  My apologies in
advance if I take a long time to catch the occasional errant process that
way.

And thanks for your ever prompt assistance and insights.

Jeff Abrahamson
+33 6 24 40 01 57
+44 7920 594 255    <-- only if I'm in the UK

http://jeff.purple.com/
http://blog.purple.com/jeff/

On 17 April 2015 at 10:09, Michael Stapelberg <mich...@i3wm.org> wrote:

> Ugh, then you’re running it in a setuid setup. You’ll need to start i3lock
> and then attach strace afterwards using -p.
>
> On Fri, Apr 17, 2015 at 9:56 AM, Jeff Abrahamson <j...@purple.com> wrote:
>
>> I invoke i3lock at the commandline thus:
>>
>> [S-18]jeff@siegfried:gtd $ strace -o/tmp/i3lock-log-$(date +%s) -f -s
>> 2048 -tt  i3lock --dpms --inactivity-timeout 10 --color=220022
>> [S-18]jeff@siegfried:gtd $
>>
>> and the result is that i3lock does not recognize my password.  It does
>> echo my typing, it just always says fail.  I switch to a vt, login, and
>> kill it.
>>
>> Jeff Abrahamson
>> +33 6 24 40 01 57
>> +44 7920 594 255    <-- only if I'm in the UK
>>
>> http://jeff.purple.com/
>> http://blog.purple.com/jeff/
>>
>> On 17 April 2015 at 09:39, Michael Stapelberg <mich...@i3wm.org> wrote:
>>
>>> Yes, but also use -f (to follow child processes) and -s 2048 (to
>>> increase the size of strings) and -tt (to get timing).
>>>
>>> On Fri, Apr 17, 2015 at 9:23 AM, Jeff Abrahamson <j...@purple.com>
>>> wrote:
>>>
>>>> Sure thing.
>>>>
>>>> Just to be clear, do you mean that instead of launching "i3lock .." I
>>>> substitute "strace -o/tmp/i3lock-log-$(date +%s) i3lock ..."?
>>>>
>>>> Jeff Abrahamson
>>>> +33 6 24 40 01 57
>>>> +44 7920 594 255    <-- only if I'm in the UK
>>>>
>>>> http://jeff.purple.com/
>>>> http://blog.purple.com/jeff/
>>>>
>>>> On 17 April 2015 at 09:19, Michael Stapelberg <mich...@i3wm.org> wrote:
>>>>
>>>>> i3lock shouldn’t hang around. Can you start stracing all your i3lock
>>>>> instances automatically and provide the corresponding strace output of a
>>>>> hung instance in a bugreport?
>>>>>
>>>>> On Fri, Apr 17, 2015 at 9:04 AM, Jeff Abrahamson <j...@purple.com>
>>>>> wrote:
>>>>>
>>>>>> I have a maintenance function that ought not bother spinning the CPU
>>>>>> if the screen is locked.  It checks this thus:
>>>>>>
>>>>>> if pidof i3lock >/dev/null; then
>>>>>>     ...
>>>>>>
>>>>>> This is i3-specific, which is sad, but not a huge problem.  What is a
>>>>>> problem is that i3lock sometimes hangs around even though I think it 
>>>>>> should
>>>>>> exit on unlock.  And, indeed, most of the time it does exit on unlock.
>>>>>> Once in a while, I find I have one or even several i3lock processes 
>>>>>> hanging
>>>>>> around.
>>>>>>
>>>>>> I either lock my screen explicitly
>>>>>>
>>>>>> bindsym $mod+Control+L exec i3lock --dpms --inactivity-timeout 10
>>>>>> --color=220022
>>>>>>
>>>>>> or else it's done by inactivity
>>>>>>
>>>>>> xautolock -detectsleep \
>>>>>>     -time 3 -locker "i3lock --dpms --color=220022
>>>>>> --inactivity-timeout 10 --nofork"
>>>>>>
>>>>>> This question thus has two parts:
>>>>>>
>>>>>> 1. Am I doing something wrong that I sometimes have multiple i3lock
>>>>>> instances?
>>>>>> 2. Is there a better way to detect screen lock than pidof i3lock?
>>>>>>
>>>>>> Jeff Abrahamson
>>>>>> +33 6 24 40 01 57
>>>>>> +44 7920 594 255    <-- only if I'm in the UK
>>>>>>
>>>>>> http://jeff.purple.com/
>>>>>> http://blog.purple.com/jeff/
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Best regards,
>>>>> Michael
>>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>> Best regards,
>>> Michael
>>>
>>
>>
>
>
> --
> Best regards,
> Michael
>

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