Re: [PATCH v5 02/16] x86: Raise minimum GCC version to 8.1

[Brian Gerst]

On Thu, Dec 5, 2024 at 6:44 AM Ard Biesheuvel <ardb@xxxxxxxxxx> wrote:
>
> On Tue, 5 Nov 2024 at 16:58, Brian Gerst <brgerst@xxxxxxxxx> wrote:
> >
> > Stack protector support on 64-bit currently requires that the percpu
> > section is linked at absolute address 0 because older compilers fixed
> > the location of the canary value relative to the GS segment base.
> > GCC 8.1 introduced options to change where the canary value is located,
> > allowing it to be configured as a standard percpu variable.  This has
> > already been done for 32-bit.  Doing the same for 64-bit will enable
> > removing the code needed to suport zero-based percpu.
> >
> > Signed-off-by: Brian Gerst <brgerst@xxxxxxxxx>
> > ---
> >  scripts/min-tool-version.sh | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/scripts/min-tool-version.sh b/scripts/min-tool-version.sh
> > index 91c91201212c..06c4e410ecab 100755
> > --- a/scripts/min-tool-version.sh
> > +++ b/scripts/min-tool-version.sh
> > @@ -19,6 +19,8 @@ binutils)
> >  gcc)
> >         if [ "$ARCH" = parisc64 ]; then
> >                 echo 12.0.0
> > +       elif [ "$SRCARCH" = x86 ]; then
> > +               echo 8.1.0
> >         else
> >                 echo 5.1.0
> >         fi
>
> There appears to be consensus that we can bump this to GCC 8.1.0 for
> all architectures:
>
> https://lore.kernel.org/all/20240925150059.3955569-32-ardb+git@xxxxxxxxxx/

That may be, but since the scope of this series is for x86, I'd rather
not have to depend on signoffs from all other arch maintainers.


Brian Gerst