[PATCH] powerpc/boot: Fix build with gcc 15

[Michal Suchánek]

On Thu, Apr 17, 2025 at 11:37:09AM +0530, Mukesh Kumar Chaurasiya wrote:
> On Fri, Mar 07, 2025 at 10:20:52AM +0100, Michal Suchanek wrote:
> > Similar to x86 the ppc boot code does not build with GCC 15.
> > 
> > Copy the fix from
> > commit ee2ab467bddf ("x86/boot: Use '-std=gnu11' to fix build with GCC 15")
> > 
> > Signed-off-by: Michal Suchanek <msuchanek at suse.de>
> > ---
> >  arch/powerpc/boot/Makefile | 1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
> > index 1ff6ad4f6cd2..e6b35699c049 100644
> > --- a/arch/powerpc/boot/Makefile
> > +++ b/arch/powerpc/boot/Makefile
> > @@ -33,6 +33,7 @@ else
> >  endif
> >  
> >  ifdef CONFIG_PPC64_BOOT_WRAPPER
> > +BOOTTARGETFLAGS	+= -std=gnu11
> >  BOOTTARGETFLAGS	+= -m64
> >  BOOTTARGETFLAGS	+= -mabi=elfv2
> >  ifdef CONFIG_PPC64_ELF_ABI_V2
> > -- 
> > 2.47.1
> > 
> There's another patch which fixes this problem by version comparison.
> https://lore.kernel.org/all/20250323163607.537270-2-misanjum@linux.ibm.com/
> 
> In my opinion this is a better solution as it will use the features of latest
> compiler.

No it's not a better solution. It's documented that the kernel is built
with the GNU dialect of ISO C11. When a file is not compiled with the
documented C dialect that's a bug.

If newer C dialect features are desirable then they should be enabled
consistently across the tree, not individually for a few files used in
boot code.

Thanks

Michal