problem with running "kill -QUIT 1" from init

[Denys Vlasenko]

On Tuesday 27 January 2009 03:14, Rob Landley wrote:
> On Thursday 22 January 2009 22:55:23 Aras Vaichas wrote:
> > One extra note, I do some trickery with /etc/inittab.
> >
> > # cat inittab.new
> >
> > ::restart:./upgrade_nand
> >
> > I change the existing inittab to run my upgrade script, tell init to
> > reload the new, and then restore the old one so I can continue testing.
> >
> > # cp /etc/inittab inittab.bak
> > # cp inittab.new /etc/inittab
> > # kill -1 1
> > # cp inittab.bak /etc/inittab
> >
> > It seems that doing "kill -1 1" from /etc/init/rcS doesn't reload the
> > inittab.
> 
> The busybox init is a bit of a hack.
> 
> I made a largeish stab at cleaning it up during the 1.0.0-pre timeframe, but 
> the source control system was frozen for several months (during the switchover 
> from cvs to svn) so I couldn't check it in, and by the time it was unfrozen 
> I'd had a laptop destroyed and lost the code.  Never got back around to 
> redoing it.
> 
> The current maintainer has chosen instead to implement a different group of 
> init-like programs (sv, runsv, runsvdir and friends, the "runit" package), 
> which can best be described as "not compatible with Ubuntu's upstart".  That's 
> what he pays attention to, not the original sysv-like init.
> 
> So my vague impression is that the init implementation in busybox has largely 
> been ignored for some time now...

No Rob, not really. While I do think that basic idea of init being responsible
for respawning daemons and stuff wasn't too bright, that does not mean
I will try to force my views on anyone by neglecting init in busybox.

There were some bugs fixed in it. I am not looking away from it.

I did not reply to this thread before because original post is lacking
details. Look at it:

On Friday 23 January 2009 05:15, Aras Vaichas wrote:
> I have a working script which allows me to unmount my jffs2 root filing 
> system so I can then write a new image to it. The problem is that it 
> only works when I test run it from a shell prompt. If I run it from my 
> /etc/init/rcS startup script, it doesn't work properly.

Great. "it doesn't work properly". I don't see the script, have no idea
how it is being run, what reporter expects to see, and what he sees instead.

Granted, I could again repeat for a zillionth time the request for more info,
but I was tired. Sorry.

> I think the problem occurs when I call chroot in the /etc/init/rcS context.
> 
> Here are the last two lines of my first script:
> ...
> ./bin/pivot_root . oldroot
> ./bin/chroot . ./bin/kill -QUIT 1

"I call chroot in the /etc/init/rcS context". I don't know how reporter
calls chroot "in the /etc/init/rcS context".

Granted, with some detective work I can figure out what it all means,
but I can spend time more productively.
Like - making uclibc testsuite to actually test at least
SOME math functions, looks like it doesn't test any
(looks like a breakage in testing machinery).
--
vda