linux-kernel - Re: [PATCH] riscv: add correct as-options for assembly in modules

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Message-ID: <b7592b63-b17e-a9d7-e4f6-bbeb417418ed@codethink.co.uk>
Date:   Fri, 16 Jul 2021 11:23:47 +0100
From:   Ben Dooks <ben.dooks@...ethink.co.uk>
To:     linux-kernel@...ts.codethink.co.uk, linux-kernel@...r.kernel.org,
        linux-riscv@...ts.infradead.org
Cc:     Paul Walmsley <paul.walmsley@...ive.com>,
        Palmer Dabbelt <palmer@...belt.com>,
        Albert Ou <aou@...s.berkeley.edu>
Subject: Re: [PATCH] riscv: add correct as-options for assembly in modules

On 12/07/2021 18:48, Ben Dooks wrote:
> When trying to load modules built for riscv which include assembly
> the kernel loader errors with "unexpected relocation type 'R_RISCV_ALIGN'"
> due to R_RISCV_ALIGN relocations being generated by the assembler.
> 
> In commit 7a8e7da42250138 ("RISC-V: Fixes to module loading")
> the fix for gcc adds -mno-relax to the command line when building
> C files. However this was never applied to assembly flags, and gcc
> does no pass -mno-relax to gas when presented with a .S file.
> 
> The fix (other than making gcc always pass -mno-relax to gas) is
> to add -Wa,-mno-relax to gcc to make sure the as is invoked with
> the right options.
> 
> Signed-off-by: Ben Dooks <ben.dooks@...ethink.co.uk>

Just wanted to find out if anyone has had time to review this.
If this is ok, should we also send to -stable ?

> ---
>   arch/riscv/Makefile | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
> index 1f5c03082976..fca40511a8c6 100644
> --- a/arch/riscv/Makefile
> +++ b/arch/riscv/Makefile
> @@ -60,6 +60,7 @@ ifeq ($(CONFIG_PERF_EVENTS),y)
>   endif
>   
>   KBUILD_CFLAGS_MODULE += $(call cc-option,-mno-relax)
> +KBUILD_AFLAGS_MODULE += $(call as-option,-Wa$(comma)-mno-relax)
>   
>   # GCC versions that support the "-mstrict-align" option default to allowing
>   # unaligned accesses.  While unaligned accesses are explicitly allowed in the
> 


-- 
Ben Dooks				http://www.codethink.co.uk/
Senior Engineer				Codethink - Providing Genius

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