Re: [PATCH 1/1] Fonts: font_acorn_8x8: Replace discarded const qualifier

[Daniel Vetter]

On Mon, Nov 2, 2020 at 12:09 PM Lee Jones <lee.jones@xxxxxxxxxx> wrote:
>
> On Mon, 02 Nov 2020, Daniel Vetter wrote:
>
> > On Fri, Oct 30, 2020 at 7:18 PM Lee Jones <lee.jones@xxxxxxxxxx> wrote:
> > >
> > > Commit 09e5b3fd5672 ("Fonts: Support FONT_EXTRA_WORDS macros for
> > > built-in fonts") introduced the following error when building
> > > rpc_defconfig (only this build appears to be affected):
> > >
> > >  `acorndata_8x8' referenced in section `.text' of arch/arm/boot/compressed/ll_char_wr.o:
> > >     defined in discarded section `.data' of arch/arm/boot/compressed/font.o
> > >  `acorndata_8x8' referenced in section `.data.rel.ro' of arch/arm/boot/compressed/font.o:
> > >     defined in discarded section `.data' of arch/arm/boot/compressed/font.o
> > >  make[3]: *** [/scratch/linux/arch/arm/boot/compressed/Makefile:191: arch/arm/boot/compressed/vmlinux] Error 1
> > >  make[2]: *** [/scratch/linux/arch/arm/boot/Makefile:61: arch/arm/boot/compressed/vmlinux] Error 2
> > >  make[1]: *** [/scratch/linux/arch/arm/Makefile:317: zImage] Error 2
> > >
> > > The .data section is discarded at link time.  Reinstating
> > > acorndata_8x8 as const ensures it is still available after linking.
> > >
> > > Cc: <stable@xxxxxxxxxxxxxxx>
> > > Cc: Russell King <linux@xxxxxxxxxxxxxxx>
> > > Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>
> >
> > Shouldn't we add the const to all of them, for consistency?
>
> The thought did cross my mind.  However, I do not see any further
> issues which need addressing.  Nor do I have any visibility into what
> issues may be caused by doing so.  The only thing I know for sure is
> that this patch fixes the compile error pertained to in the commit
> message, and I'd like for this fix to be as atomic as possible, as
> it's designed to be routed through the Stable/LTS trees.

The trouble is that if we only make one of them const, then it'll take
so much longer to hit any issues due to code not handling this
correctly. Being consistent with all fonts sounds like the best
approach.

And the original patch that lost the const for the additional data
also went through cc: stable for all fonts together. So that shouldn't
be the hold-up.
-Daniel

>
> --
> Lee Jones [李琼斯]
> Senior Technical Lead - Developer Services
> Linaro.org │ Open source software for Arm SoCs
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch