Re: arch/x86/Makefile REALMODE_CFLAGS needs -std=gnu11 with recent GCC versions

From: Borislav Petkov
Date: Sun Jun 29 2025 - 11:34:13 EST


+ stable folks.

On Sun, Jun 29, 2025 at 11:15:13AM -0400, Dennis Clarke wrote:
>
> Code fix for due to https://bugzilla.kernel.org/show_bug.cgi?id=220294
>
> The summary is that recent GCC versions ( 15.1.0 today ) will assume C23
> spec compliance and get upset with ye old A20 address line code bits.
>
> This problem exists previous to the 6.12.35 release tarballs and is
> fixed with commit b3bee1e7c3f2b1b77182302c7b2131c804175870 applied.
>
> The newer GCC revisions will be quite popular soon enough and this may
> bite people when that happens.

I don't know what the rules are for building 6.1-stable with gcc-15 but if
they do that, then 6.1 will need to pick up the abovementioned commit:

b3bee1e7c3f2 ("x86/boot: Compile boot code with -std=gnu11 too")

Thx.

--
Regards/Gruss,
Boris.

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