GCC 7.3 released

GCC 7.3 is out. This is mainly a bug-fix release, but it does also contain the "retpoline" support needed to build the kernel (and perhaps other code) with resistance to the Spectre variant-2 vulnerability.

From:		Richard Biener <rguenther-AT-suse.de>
To:		gcc-announce-AT-gcc.gnu.org, gcc-AT-gcc.gnu.org, info-gnu-AT-gnu.org
Subject:		GCC 7.3 Released
Date:		Thu, 25 Jan 2018 10:41:30 +0100 (CET)
Message-ID:		<alpine.LSU.2.20.1801251039290.18265@zhemvz.fhfr.qr>


The GNU Compiler Collection version 7.3 has been released.

GCC 7.3 is a bug-fix release from the GCC 7 branch
containing important fixes for regressions and serious bugs in
GCC 7.2 with more than 99 bugs fixed since the previous release.

This release includes code generation options to mitigate
Spectre Variant 2 (CVE 2017-5715) for the x86 and powerpc targets.

This release is available from the FTP servers listed at:

  http://www.gnu.org/order/ftp.html

Please do not contact me directly regarding questions or comments
about this release.  Instead, use the resources available from
http://gcc.gnu.org.

As always, a vast number of people contributed to this GCC release
-- far too many to thank them individually!

-- 
If you have a working or partly working program that you'd like
to offer to the GNU project as a GNU package,
see https://www.gnu.org/help/evaluation.html.

GCC 7.3 released

Posted Jan 27, 2018 17:20 UTC (Sat) by cyperpunks (subscriber, #39406) [Link] (1 responses)

Can you explain more about retpoline, what happens if only kernel is retpoline compiled?

GCC 7.3 released

Posted Jan 27, 2018 21:55 UTC (Sat) by nivedita76 (subscriber, #121790) [Link]

See Meltdown/Spectre mitigation. Not sure what you're asking with second q, but if only kernel is compiled with Retpoline, naturally only the kernel is protected against Spectre Variant 2.

GCC 7.3 released

Posted Jan 30, 2018 22:03 UTC (Tue) by kjhambrick (guest, #23704) [Link] (6 responses)

Curious because I run Slackware 14.2 ...

Does anyone know if I should be watching for back-ports of the retpoline code in say, gcc 5.3.x ?

Thanks !

-- kjh

GCC 7.3 released

Posted Jan 31, 2018 9:16 UTC (Wed) by amacater (subscriber, #790) [Link] (3 responses)

Unlikely in the extreme, I'd have said - there's enough change in the last few years that it would be infeasible. You'd be easier installing from a tarball of 7.3 yourself and then compiling kernel 4.15 for yourself or nagging Patrick and the rest. Maybe you need a Slackware 14.2.1 "Doesn't melt" point release to be made :)

[Although pbonzini suggests that all fixes will be backported to 4.14 as the LTS version above, I suspect that the amount of work will mean that it's only for paying enterprise customers - the kernel fixes are still very much ongoing and some of the ARM64 fixes will only start in 4.16 if I read it correctly?]

GCC 7.3 released

Posted Feb 2, 2018 13:30 UTC (Fri) by kjhambrick (guest, #23704) [Link] (2 responses)

Thanks amacater.

Yes, I imagine you're correct.

If I want the Spectre fixes, I'll have to upgrade from Slackware64 14.2 to 15.0 when it is released .

I've never had to do that before -- Slackware since Version 7.0 has always remained Secure and Stable as long as my Hardware lived :)

Odd situation though with Spectre in that it requires both compiler and kernel patches for 'mitigation'.

The 4.4.113+ Kernels are ready but gcc 5.3.0 is not.

Thanks again !

-- kjh

GCC 7.3 released

Posted Feb 7, 2018 18:03 UTC (Wed) by jfb (subscriber, #60805) [Link] (1 responses)

Today's Slackware 14.2 ChangeLog contains this entry:

patches/packages/gcc-5.5.0-x86_64-1_slack14.2.txz: Upgraded.
Upgraded to the latest gcc-5 release, with patches to support
-mindirect-branch=thunk-extern, allowing full mitigation of Spectre v2
in the kernel (when CONFIG_RETPOLINE is used).

And also an upgrade to linux-4.4.115.

GCC 7.3 released

Posted Feb 7, 2018 18:40 UTC (Wed) by kjhambrick (guest, #23704) [Link]

Thanks jfb !

Yes, I've already downloaded and installed the updates on two Slackware64 14.2 Systems

Now I am studying Eric Hameleers( aka Alien Bob )'s multilib gcc and glibc SlackBuilds so I can try to bootstrap multilib versions on my working Laptop some time this weekend.

Thanks again !

-- kjh

GCC 7.3 released

Posted Feb 2, 2018 7:49 UTC (Fri) by bernat (subscriber, #51658) [Link] (1 responses)

You can find backports in this tree: https://github.com/hjl-tools/gcc/tree/hjl/indirect/gcc-5-....

GCC 7.3 released

Posted Feb 2, 2018 13:17 UTC (Fri) by kjhambrick (guest, #23704) [Link]

Thank you, bernat.

Very helpful link !

I'll keep an eye on the 5.3.0 ChangeLog.

-- kjh