Profile 17.0

NeddySeagoon · Posted: Mon Jan 08, 2018 9:14 pm Post subject:

ct85711,

Neither need a full system build.

The gcc-4.x to >=gcc-5.y change needs all the installed C++ to be rebuilt due to the ABI change.
The (-pie) to (+pie) change, managed with the /17.0/ profile needs all the static libraries to be rebuilt.

Hardened profile users have been on (+pie) for a long time, so the upgrade may be a noop for them.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

eccerr0r · Posted: Tue Jan 09, 2018 1:33 am Post subject:

Fortunately my i686 was able to build gcc-6.4 with gcc-4.9.4, though I haven't gone through with PIEing or rebuilding c++ yet on this machine...
_________________
Intel Core i7 2700K/Radeon R7 250/24GB DDR3/256GB SSD
What am I supposed watching?

krinn · Watchman Joined: 02 May 2003 Posts: 7470

because of "incoming" spectre patch mitigation for gcc, i would just wait with my 4.9.
and when "spectre"-gcc is out, i would download latest stage3, chroot, build the new gcc with the toolchain from the chroot : so no upgrade to 4.9->? just using toolchain from stage3 and upgrade to spectre-gcc (which should be 8, but we might have a 7-3 or 7.4 ready), but i really don't expect gcc 6 series to have them backport to it.

jorgicio · n00b Joined: 17 Oct 2014 Posts: 47

In resume: if I just build static-related packages (after migrate of profile and building gcc and other packages with PIE, of course), Am I done and then I'll (re)build everything I want? (In order to avoid the emerge -e @world which takes ages to do so)

NeddySeagoon · Posted: Wed Jan 10, 2018 1:39 pm Post subject:

krinn,

gcc builds itself three times in the course of the install.
It builds a bootstrap gcc with the random C++ compiler it finds on the system.
It uses that bootstrap gcc to build itself, then it compares the two gccs, which should be identical.

Lastly, it uses the second gcc to build the gcc targets that actually get installed.

This build system means that distcc can't help build gcc
Bootstrapping gcc this way only works for native builds.

That's a long way to say don't bother waiting for a stage3.
Build your new gcc.
Use it ts build the toolchain.
If you are really paranoid, do it again.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

Vandon · n00b Joined: 04 Jan 2004 Posts: 29

I've updated my system to a 17.0 profile and everything seemed to go well with re-emerging everything.
I went to: [19] default/linux/amd64/17.0/desktop/plasma *

However, once the 17.1 profiles were removed, I started getting this message every time I emerge something:

NeddySeagoon · Posted: Wed Jan 10, 2018 5:21 pm Post subject:

Vandon,

The message is displayed because you have a file named depreciated in your profile.
See

Vandon · n00b Joined: 04 Jan 2004 Posts: 29

proteusx · Guru Joined: 21 Jan 2008 Posts: 338

You get this message if the symlink '/etc/portage/make.profile' is invalid.

Vandon · n00b Joined: 04 Jan 2004 Posts: 29

wrc1944 · Posted: Wed Jan 10, 2018 11:57 pm Post subject:

tld,
I'm currently running three rock solid gentoo ~amd64 gcc-7.2 profile 13.0 (global -pie) Ryzen systems, and am contemplating using your method of moving to a -pie profile 17 on page 8 of this profile 17.0 thread.
Anyway, posted on page 7 of this thread I'm still wondering how profile 17 with default pie might fare on AM4/Ryzen considering some known and possibly related Ryzen problems, and a few experts offered some thoughts. I've gained a little more understanding, but I'm not convinced I should try a full default pie profile 17 change, even on ~amd64 systems. I'm aware that the pie performance hits are reported as mainly a 32bit problem, but with known ryzen ASLR flaws, I still feel a little apprehensive. If I wasn't on Ryzen, I probably would just go ahead and do the profile 17.0 update, and hope for the best, even if I'm still not convinced I need pie.

equery hasuse pie lists my current GCC, which I take implies GCC is already built with pie (not sure on this),

patrix_neo · Guru Joined: 08 Jan 2004 Posts: 520 Location: The Maldives

NeddySeagoon · Posted: Fri Jan 19, 2018 9:21 pm Post subject:

patrix_neo,

Its the way the kernel build system works. Its not built with emerge. emerge only installs the sources for you, so the settings in make.conf are not used for kernel builds.

If you know the environment variables to set, you can set them on the command line with the make command.
Then you get to keep the pieces if the resulting kernel fails in funny ways as it did with gentoo-hardened's gcc recently.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

Havin_it · Posted: Sun Jan 21, 2018 2:51 pm Post subject:

I'm about to go through this on my server box, got one small question: The news item specifies gcc:6.4.0, but is it fine to use gcc:7.2.0 instead?

The box is quite out-of-date (~400 updates queued!) and hasn't got gcc:7.2.0 yet. So is this sequence alright?

pjp · Administrator Joined: 16 Apr 2002 Posts: 20067

gcc 7.2 is fine with profile 17.

But depending on the version of gcc you currently have installed, there may be some additional steps.

Upgrading from gcc-4.x to gcc-5.x

Otherwise I've followed Upgrading GCC. Despite the reference to not having to do it the "long way," I followed the unstated advice to do it anyway:

Havin_it · Posted: Sun Jan 21, 2018 11:28 pm Post subject:

Hi pjp, thanks for the reply.

I've had gcc:6.4 installed for a few months (since last emerge -u @world) but none of my system is built with it (not even libtool until just now -- oops) but rather with gcc:5.3.0.

So if I update to 17.0 now, I can then build gcc:7.2.0 once (followed by switching to it and using it to build libtool, binutils and glibc) and then just proceed with the world rebuild?

pjp · Administrator Joined: 16 Apr 2002 Posts: 20067

I can't find my notes on my upgrade. Nor the posts I relied upon.

Since you apparently accidentally built libtool with gcc-6.4, I'm not sure how significant that is. I don't know if you can have a gcc-5 environment with libtool compiled with gcc-6 and then migrate everything to gcc-7 and profile 17 in "one step."

I'm going to defer to more experienced users on this one. Unless I'm personally pretty clear that stuff isn't going to hit the fan, I try not to fix things by breaking them more. :)

Otherwise, I would have installed gcc-7.2, rebuilt the toolchain, switched to the 17 profile, rebuilt the toolchain (for pie, etc) and then -ea @system and -ea @world.
_________________
Quis separabit? Quo animo?

trigggl · Posted: Fri Feb 02, 2018 7:15 am Post subject:

trigggl · Posted: Fri Feb 02, 2018 7:24 am Post subject: