Bug 199305

Description of problem:

When init re-execs itself (from telinit u etc), it doesn't (attempt to) preserve
the WAITING flag, so if this happens while a startup script (say) is being run,
init goes off and runs the next init line in the inittab anyway...

Version-Release number of selected component (if applicable):

I've checked the source of SysVinit-2.85-4.4 (from EL3), but the same code seems
to be present in the version in EL4 and in the upstream 2.86

How reproducible:

100%

Steps to Reproduce:
1.  (this is a trivial example) add inittab entries like

jsp1:5:wait:/root/test1
jsp2:5:wait:/root/test2

where each script does some work and sleeps before finishing off.

e.g.
#! /bin/bash
#
exec >> /root/abyno 2>&1
echo in test1
date
sleep 60
date
echo 'got to end!'

(and similar for the other).

On HUP'ing init they would be run (normally) in order: test1, test2.

2. kill -1 1
3. telinit u
  
Actual results:

as soon as the telinit u is sent the 2nd script is started (before the fist has
finished).

Expected results:

the 2 scripts to run in order as they would without the 'telinit u'

Additional info:

In the default EL3/EL4 /etc/inittab we have entries like:

...
l5:5:wait:/etc/rc.d/rc 5
...
1:2345:respawn:/sbin/mingetty tty1
2:2345:respawn:/sbin/mingetty tty2
...
x:5:respawn:/etc/X11/prefdm -nodaemon

if one of the init scripts from rc5.d results in 'telinit u' happening then the
getty's and gdm (or whatever) get started *before* the init scripts have
finished.  In particular this is likely to be before xfs gets started so gdm
won't work very well (this scares the hell out of my users!)

In my case an init script attempts to apply missed updates (e.g. from when a
machine was off etc), so when (say) glibc (or sysvinit) get upgraded the
postinstall scriptlet ends up doing a telinit u so gdm (and getty's) get
spawned.  My users seem to think that the machine is broken and tend to turn it
back off again...  The flashing X/gdm failing can eventually get to the 'I can't
start an X server' warning which worries some users...

Of course there might be a good reason why WAITING isn't preserved over a
re-exec, but I don't understand the code well enough to be 100% sure.