Re: [gentoo-user] Re: gcc 7.3 + kernel 4.15 = spectre_v2 fixed

[Mike Gilbert <floppym@gentoo.org>]

On Mon, Jan 29, 2018 at 1:56 PM, Mick <michaelkintzios@gmail.com> wrote:
> On Monday, 29 January 2018 18:35:58 GMT Mike Gilbert wrote:
>> On Mon, Jan 29, 2018 at 12:50 PM, Ian Zimmerman <itz@very.loosely.org>
> wrote:
>> > On 2018-01-29 20:11, Adam Carter wrote:
>> >> Comparing the contents of
>> >> /sys/devices/system/cpu/vulnerabilities/spectre_v2
>> >>
>> >> With gcc 7.2 + kernel 4.14.15;
>> >> Intel system shows; Vulnerable: Minimal generic ASM retpoline
>> >> AMD system shows: Vulnerable: Minimal AMD ASM retpoline
>> >>
>> >> With gcc 7.3 + kernel 4.15.0;
>> >> Intel system shows; Mitigation: Full generic retpoline
>> >> AMD system shows' Mitigation: Full AMD retpoline
>> >
>> > Is there a simple way, with the upstream (kernel.org) sources, to force
>> > a compiler different from the system default?  If there is, it's not in
>> > the
>> > README, and a simple grep over the Makefiles also doesn't enlighten.
>> >
>> > I am not ready to activate a keyworded gcc for general use.
>>
>> You could pass CC=gcc-7.3.0 to the make command, like so:
>>
>> make -j6 CC=gcc-7.3.0
>
> Shouldn't you have at least compiled your whole toolchain with gcc-7.3.0
> first?

I don't see any reason that would be necessary.