Bug#132542: sysvinit: please make /etc/init.d/rcS a conffile

[Adam Borowski]

On Sat, Jan 19, 2019 at 07:34:26PM +0000, Dmitry Bogatov wrote:
> [2019-01-18 02:20] Adam Borowski <kilobyte at angband.pl>
> > That ship has long since sailed.  What's the point of making sysv-rc support
> > non-/usr early boot if the rest of the system doesn't?  It may still work on
> > some simple installs, but even that quite rapidly degrades as random
> > packages get changed to simplify this away.
> 
> The same argument could be applied to many other things: systemd,
> web-2.0, html emails, MS Office, GitLab/Hub. Still, I use runit init
> system, text browser, text mail client and still send patches via
> git-send-email.
> 
> I object when someone appears and try break my beautiful little
> paradise.  And I definitely do not want to come and break someone's
> else.

That's not what my argument is -- what I mean, is that there's many more
components that need to stick strictly to files not on /usr during that
phase of the boot, sysv-rc being only a single one.  Efforts to keep it
working are a waste of time, not because you won't get to simplify things,
but because you would need to override a number of other maintainers.

Simple setups still work in Buster, but it's easy to run into something that
doesn't.  That'd be a nasty surprise for the user, thus it's better to make
the break faster and more obvious.  Then, pretty surely even such simple
setups won't work in Bullseye.

> > >   Okay. I moved {rc, rcS} to /lib (see commit 51170798), change will be
> > >   in 2.93-4 (due in few days). Sysvinit will *not* assume, that /usr is
> > >   mounted at /sbin/init invocation in Buster. I promise.
> > 
> > That's a waste of your time.  Both for and after Buster.
> 
> That is being responsible to my users. I do not consider it waste.

There's a cost to migrations like this: any move may break stuff.  For
example, it breaks that silly little init I used to have in my .sig (and
included in this mail), but people may refer to that file for reasons other
than mere fun.

There's an easy way for Buster: just drop the move, it serves no need.


Meow!
-- 
⢀⣴⠾⠻⢶⣦⠀ .globl _start↵.data↵rc: .ascii "/etc/init.d/rcS\0"↵.text↵_start
⣾⠁⢰⠒⠀⣿⡁ mov $57,%rax↵syscall↵cmp $0,%rax↵jne child↵parent:↵mov $61,%rax
⢿⡄⠘⠷⠚⠋⠀ mov $-1,%rdi↵xor %rsi,%rsi↵xor %rdx,%rdx↵syscall↵jmp parent↵child:
⠈⠳⣄⠀⠀⠀⠀ mov $59,%rax↵mov $rc,%rdi↵xor %rsi,%rsi↵xor %rdx,%rdx↵syscall