On Tue, Jul 6, 2021 at 6:18 AM Huacai Chen <chenhuacai@xxxxxxxxxxx> wrote:
>
> +/*
> + * long __strncpy_from_user(char *to, const char *from, long len)
> + *
> + * a0: to
> + * a1: from
> + * a2: len
> + */
> +SYM_FUNC_START(__strncpy_from_user)
> + move a3, zero
> +
I doubt this is better than the C version in lib/strncpy_from_user.c
> diff --git a/arch/loongarch/lib/strnlen_user.S b/arch/loongarch/lib/strnlen_user.S
> new file mode 100644
> index 000000000000..9288a5ad294e
> --- /dev/null
> +++ b/arch/loongarch/lib/strnlen_user.S
> @@ -0,0 +1,47 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
> + */
Same here.
Have you done any measurement to show that the asm version actually helps
here? If not, just use the generic version.
Arnd
