Re: [PATCH v2] RISC-V: fix compile error from deduplicated __ALTERNATIVE_CFG_2

["Heiko Stübner" <heiko@sntech.de>]

Am Donnerstag, 5. Januar 2023, 21:47:47 CET schrieb Palmer Dabbelt:
> On Thu, 05 Jan 2023 11:26:10 PST (-0800), heiko@sntech.de wrote:
> > From: Heiko Stuebner <heiko.stuebner@vrull.eu>
> >
> > On the non-assembler-side wrapping alternative-macros inside other macros
> > to prevent duplication of code works, as the end result will just be a
> > string that gets fed to the asm instruction.
> >
> > In real assembler code, wrapping .macro blocks inside other .macro blocks
> > brings more restrictions on usage it seems and the optimization done by
> > commit 2ba8c7dc71c0 ("riscv: Don't duplicate __ALTERNATIVE_CFG in __ALTERNATIVE_CFG_2")
> > results in a compile error like:
> >
> > ../arch/riscv/lib/strcmp.S: Assembler messages:
> > ../arch/riscv/lib/strcmp.S:15: Error: too many positional arguments
> > ../arch/riscv/lib/strcmp.S:15: Error: backward ref to unknown label "886:"
> > ../arch/riscv/lib/strcmp.S:15: Error: backward ref to unknown label "887:"
> > ../arch/riscv/lib/strcmp.S:15: Error: backward ref to unknown label "886:"
> > ../arch/riscv/lib/strcmp.S:15: Error: backward ref to unknown label "887:"
> > ../arch/riscv/lib/strcmp.S:15: Error: backward ref to unknown label "886:"
> > ../arch/riscv/lib/strcmp.S:15: Error: attempt to move .org backwards
> >
> > Wrapping the variables containing assembler code in quotes solves this issue,
> > compilation and the code in question still works and objdump also shows sane
> > decompiled results of the affected code.
> >
> > Fixes: 2ba8c7dc71c0 ("riscv: Don't duplicate __ALTERNATIVE_CFG in __ALTERNATIVE_CFG_2")
> > Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
> > ---
> > changes in v2:
> > - don't revert the affected cleanup but use quotes around the parts
> >
> > Tested on qemu + Allwinner D1 + specially created test-cases using
> > ALTERNATIVE_2 in full assembler .S files
> >
> >  arch/riscv/include/asm/alternative-macros.h | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/arch/riscv/include/asm/alternative-macros.h b/arch/riscv/include/asm/alternative-macros.h
> > index 7226e2462584..2c0f4c887289 100644
> > --- a/arch/riscv/include/asm/alternative-macros.h
> > +++ b/arch/riscv/include/asm/alternative-macros.h
> > @@ -46,7 +46,7 @@
> >
> >  .macro ALTERNATIVE_CFG_2 old_c, new_c_1, vendor_id_1, errata_id_1, enable_1,	\
> >  				new_c_2, vendor_id_2, errata_id_2, enable_2
> > -	ALTERNATIVE_CFG \old_c, \new_c_1, \vendor_id_1, \errata_id_1, \enable_1
> > +	ALTERNATIVE_CFG "\old_c", "\new_c_1", \vendor_id_1, \errata_id_1, \enable_1
> >  	ALT_NEW_CONTENT \vendor_id_2, \errata_id_2, \enable_2, \new_c_2
> >  .endm
> 
> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
> 
> I'm going to hold off on this one for this week, though -- at least to 
> give it some time on the lists, but it appears this hasn't landed at 
> lore/patchwork yet and thus might be stuck.  It is in the mailman 
> archives...

No worries - there isn't any real-word breakage happening with 6.2-rc
So we're in no particular rush to fix somebodies broken boardfarm :-)

Heiko

> http://lists.infradead.org/pipermail/linux-riscv/2023-January/024682.html
> 





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