Re: [PATCH] aes-gcm-p10: Use the correct bit to test for P10

From: Michael Ellerman
Date: Thu Nov 07 2024 - 06:43:31 EST


Michal Suchanek <msuchanek@xxxxxxx> writes:
> A hwcap feature bit is passed to cpu_has_feature, resulting in testing
> for CPU_FTR_MMCRA instead of the 3.1 platform revision.

Ouch. Good find.

Notably all IBM Power CPUs have MMCRA set, so the feature test is
essentially a nop.

> Fixes: c954b252dee9 ("crypto: powerpc/p10-aes-gcm - Register modules as SIMD")

^ which is only in linux-next so no stable tag needed.

> Reported-by: Nicolai Stange <nstange@xxxxxxxx>
> Signed-off-by: Michal Suchanek <msuchanek@xxxxxxx>
> ---
> arch/powerpc/crypto/aes-gcm-p10-glue.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)

Acked-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> (powerpc)

cheers

> diff --git a/arch/powerpc/crypto/aes-gcm-p10-glue.c b/arch/powerpc/crypto/aes-gcm-p10-glue.c
> index e52629334cf8..1f8b67775658 100644
> --- a/arch/powerpc/crypto/aes-gcm-p10-glue.c
> +++ b/arch/powerpc/crypto/aes-gcm-p10-glue.c
> @@ -414,7 +414,7 @@ static int __init p10_init(void)
> {
> int ret;
>
> - if (!cpu_has_feature(PPC_FEATURE2_ARCH_3_1))
> + if (!cpu_has_feature(CPU_FTR_ARCH_31))
> return 0;
>
> ret = simd_register_aeads_compat(gcm_aes_algs,
> --
> 2.46.1