Bug 485598 – CONFIG_PROTECT fails to protect symlinks

• Product: Portage Development
• Status: RESOLVED FIXED

[Description Jeroen Roovers (RETIRED) 2013-09-21 17:37:13 UTC]

With CONFIG_PROTECT="... /usr/lib/distcc/bin"

Before reinstalling sys-devel/distcc:

elmer /usr/lib/distcc/bin # ls -l
c++ -> hppa2.0-unknown-linux-gnu
cc -> hppa2.0-unknown-linux-gnu
g++ -> hppa2.0-unknown-linux-gnu
gcc -> hppa2.0-unknown-linux-gnu
hppa2.0-unknown-linux-gnu
hppa2.0-unknown-linux-gnu-c++ -> /usr/bin/distcc
hppa2.0-unknown-linux-gnu-g++ -> /usr/bin/distcc
hppa2.0-unknown-linux-gnu-gcc -> /usr/bin/distcc

After reinstalling sys-devel/distcc:

elmer /usr/lib/distcc/bin # ls -l
c++ -> /usr/bin/distcc
cc -> /usr/bin/distcc
g++ -> /usr/bin/distcc
gcc -> /usr/bin/distcc
hppa2.0-unknown-linux-gnu
hppa2.0-unknown-linux-gnu-c++ -> /usr/bin/distcc
hppa2.0-unknown-linux-gnu-g++ -> /usr/bin/distcc
hppa2.0-unknown-linux-gnu-gcc -> /usr/bin/distcc

I need to run

for i in c* g*; do rm -v $i && ln -sv hppa2.0-unknown-linux-gnu $i; done

after every reinstall (to make the symlinks point to a script that auto-corrects [cg]* --> hppa2.0-unknown-linux-gnu-[cg]* and issues a warning on stderr.

I don't see why these symlinks are not protected. Apparently similar bugs were fixed in sys-apps/portage in the past.

bug #54053 	cri 	High 	[e-mail] 	RESO 	FIXE 	Linu 	CONFIG_PROTECT does not work for symlinks 
bug #151502 	nor 	High 	[e-mail] 	RESO 	FIXE 	Linu 	CONFIG_PROTECT and symlinks

[Comment 1 Mike Gilbert 2014-09-25 14:23:31 UTC]

I would also like to see this fixed.

sys-apps/systemd installs a number of symlinks in /etc/systemd by default, and these may manipulated by the sysadmin to adjust their system startup. However, any changes get clobbered when you upgrade systemd.

We currently work around this by removing the symlinks in src_install and forcing the user to create them manually via 'systemctl enable'.

[Comment 2 Zac Medico 2014-10-23 11:00:49 UTC]

I've started working on this in the following branch:

	https://github.com/zmedico/portage/tree/bug_485598

Most of the changes to the merge code are complete. I haven't started on etc-update/dispatch-conf support yet.

[Comment 3 Zac Medico 2014-10-24 08:07:23 UTC]

The etc-update behavior for merging a regular file where there's an existing symlink is update the regular file that the symlink points to (see bug #330221). Please comment if you have a problem with that. Otherwise, I'll assume that this behavior is acceptable.

[Comment 4 Jeroen Roovers (RETIRED) 2014-10-24 08:40:18 UTC]

(In reply to Zac Medico from comment #3)
> The etc-update behavior for merging a regular file where there's an existing
> symlink is update the regular file that the symlink points to (see bug
> #330221). Please comment if you have a problem with that. Otherwise, I'll
> assume that this behavior is acceptable.

That should be fine as long as CONFIG_PROTECT enables me to get rid of the updates. :)

Case in point is /usr/lib/distcc/bin, where I replace the usual symlinks to /usr/bin/distcc with symlinks to a script matching the canonical toolchain tuple:

/usr/lib/distcc/bin/c++ -> x86_64-pc-linux-gnu
(and so on).

The /usr/lib/distcc/bin/x86_64-pc-linux-gnu script is mine, and any updates I could just throw away again.

The only problem I see is that it might then offer me a comparison between an executable binary and a script. :)

[Comment 5 Zac Medico 2014-10-25 09:33:30 UTC]

(In reply to Zac Medico from comment #2)
> I've started working on this in the following branch:
> 
> 	https://github.com/zmedico/portage/tree/bug_485598

It's basically complete now. There are lots of changes, and I need review it all. Then I'll post a patch and ask for testers.

[Comment 6 Zac Medico 2014-10-26 11:15:10 UTC]

I've posted patches for review here:

http://thread.gmane.org/gmane.linux.gentoo.portage.devel/4687

[Comment 7 Zac Medico 2014-11-03 04:52:26 UTC]

This is in git now:

https://github.com/gentoo/portage/commit/02417188225758b1822d176abd8902a92300a371
https://github.com/gentoo/portage/commit/f17448317166bfac42dc279b8795cd581c189582
https://github.com/gentoo/portage/commit/6659c00a580254f68460608b4cdc5df8e057d17c

[Comment 8 Zac Medico 2014-12-06 23:33:04 UTC]

This is fixed in 2.2.15.