Re: [PATCH 4/4] sparc: fix accurate exception reporting in copy_{from_to}_user for Niagara 4

[John Paul Adrian Glaubitz]

Hello,

On Tue, 2025-08-26 at 18:03 +0200, Michael Karcher wrote:
> Fixes: 957077048009 ("sparc64: Convert NG4copy_{from,to}_user to accurate exception reporting.")
> Signed-off-by: Michael Karcher <kernel@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>
> ---
>  arch/sparc/lib/NG4memcpy.S | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/sparc/lib/NG4memcpy.S b/arch/sparc/lib/NG4memcpy.S
> index 7ad58ebe0d00..df0ec1bd1948 100644
> --- a/arch/sparc/lib/NG4memcpy.S
> +++ b/arch/sparc/lib/NG4memcpy.S
> @@ -281,7 +281,7 @@ FUNC_NAME:	/* %o0=dst, %o1=src, %o2=len */
>  	subcc		%o5, 0x20, %o5
>  	EX_ST(STORE(stx, %g1, %o0 + 0x00), memcpy_retl_o2_plus_o5_plus_32)
>  	EX_ST(STORE(stx, %g2, %o0 + 0x08), memcpy_retl_o2_plus_o5_plus_24)
> -	EX_ST(STORE(stx, GLOBAL_SPARE, %o0 + 0x10), memcpy_retl_o2_plus_o5_plus_24)
> +	EX_ST(STORE(stx, GLOBAL_SPARE, %o0 + 0x10), memcpy_retl_o2_plus_o5_plus_16)
>  	EX_ST(STORE(stx, %o4, %o0 + 0x18), memcpy_retl_o2_plus_o5_plus_8)
>  	bne,pt		%icc, 1b
>  	 add		%o0, 0x20, %o0

Verified to not cause any regressions on SPARC T4. Whether it improved anything is
hard to say. It might be that previously observed crashes after long uptimes are
gone now.

Tested-by: John Paul Adrian Glaubitz <glaubitz@xxxxxxxxxxxxxxxxxxx>

Adrian

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