Re: [PATCH] riscv: alternative: proceed one more instruction for auipc/jalr pair

From: Andrew Jones
Date: Thu Jan 19 2023 - 03:45:43 EST


On Mon, Jan 16, 2023 at 12:28:11AM +0800, Jisheng Zhang wrote:
> If we patched auipc + jalr pair, we'd better proceed one more
> instruction. Andrew pointed out "There's not a problem now, since
> we're only adding a fixup for jal, not jalr, but we should
> future-proof this and there's no reason to revisit an already fixed-up
> instruction anyway."
>
> Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxx>
> Suggested-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx>
> ---
> arch/riscv/kernel/alternative.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/riscv/kernel/alternative.c b/arch/riscv/kernel/alternative.c
> index fc341b69bf62..2354c69dc7d1 100644
> --- a/arch/riscv/kernel/alternative.c
> +++ b/arch/riscv/kernel/alternative.c
> @@ -122,6 +122,7 @@ void riscv_alternative_fix_offsets(void *alt_ptr, unsigned int len,
>
> riscv_alternative_fix_auipc_jalr(alt_ptr + i * sizeof(u32),
> insn, insn2, patch_offset);
> + i++;
> }
>
> if (riscv_insn_is_jal(insn)) {
> --
> 2.38.1
>

Reviewed-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx>