Thanks. I understand (and a bit better, now) why strace/ptrace may have
problems with a program that calls setuid. On the other hand, i3lock
doesn't have the setuid bit set, and the strace logs do not show an attempt
to call strace.
[S-18]jeff@siegfried:~ $ stat /usr/bin/i3lock
File: ‘/usr/bin/i3lock’
Size: 31912 Blocks: 64 IO Block: 4096 regular file
Device: fc01h/64513d Inode: 1575208 Links: 1
Access: (0755/-rwxr-xr-x) Uid: ( 0/ root) Gid: ( 0/ root)
Access: 2015-04-16 20:02:56.634223226 +0200
Modify: 2014-07-19 01:13:09.000000000 +0200
Change: 2015-03-04 15:18:43.959784604 +0100
Birth: -
[S-18]jeff@siegfried:~ $ grep setuid /tmp/i3lock-log-1429256*
1,[S-18] jeff@siegfried:~ $
This said, if something PAM did when I logged in affects the behavior of
stracing i3lock, I do not think I will try to figure out what PAM has done.
;-) But I still find it odd that i3lock would interpret keystrokes
differently under strace or not based on what I know so far.
Well, I will debug what I can. Maybe I will compile an i3lock with
scaffolding over the weekend to see what I can learn.
Thanks again.
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 11:47, Michael Stapelberg <michael@xxxxxxxx> wrote:
See http://superuser.com/a/248127 for why setuid is ignored when
running under strace.
Given that you run i3lock on linux, it might be PAM which uses setuid
in some of its modules.
On Fri, Apr 17, 2015 at 1:20 AM, Jeff Abrahamson <jeff@xxxxxxxxxx> wrote:
Interesting. How does setuid have this effect on i3lock but only underis
strace?
Any idea where the setuid is coming from or how to find out? The system
pretty vanilla ubuntu 14.10 (they have a good installer) aside fromrunning
i3 instead of gnome.advance
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
if I take a long time to catch the occasional errant process that way.i3lock
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 <michael@xxxxxxxx> wrote:
Ugh, then you’re running it in a setuid setup. You’ll need to start
wrote:and then attach strace afterwards using -p.
On Fri, Apr 17, 2015 at 9:56 AM, Jeff Abrahamson <jeff@xxxxxxxxxx>
and kill
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,
wrote: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 <michael@xxxxxxxx>
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 <jeff@xxxxxxxxxx>
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 <michael@xxxxxxxx>
of a
i3lock shouldn’t hang around. Can you start stracing all your i3lock
instances automatically and provide the corresponding strace output
CPUhung instance in a bugreport?
On Fri, Apr 17, 2015 at 9:04 AM, Jeff Abrahamson <jeff@xxxxxxxxxx>
wrote:
I have a maintenance function that ought not bother spinning the
is aif 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
it shouldproblem is that i3lock sometimes hangs around even though I think
unlock. Onceexit on unlock. And, indeed, most of the time it does exit on
hangingin a while, I find I have one or even several i3lock processes
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
--
Best regards,
Michael