[PATCH bpf-next 1/3] riscv, bpf: Fix support for BPF_SDIV and BPF_SMOD in RV32 JIT

[bot+bpf-ci at kernel.org]

> diff --git a/arch/riscv/net/bpf_jit_comp32.c b/arch/riscv/net/bpf_jit_comp32.c
> index 592dd86fbf81..7396899ea276 100644
> --- a/arch/riscv/net/bpf_jit_comp32.c
> +++ b/arch/riscv/net/bpf_jit_comp32.c
> @@ -509,7 +509,7 @@ static void emit_alu_r64(const s8 *dst, const s8 *src,
>  }
>
>  static void emit_alu_r32(const s8 *dst, const s8 *src,
> -			 struct rv_jit_context *ctx, const u8 op)
> +			 struct rv_jit_context *ctx, const u8 op, bool is_sdiv)
>  {
>  	const s8 *tmp1 = bpf2rv32[TMP_REG_1];
>  	const s8 *tmp2 = bpf2rv32[TMP_REG_2];
> @@ -539,10 +539,16 @@ static void emit_alu_r32(const s8 *dst, const s8 *src,
>  		emit(rv_mul(lo(rd), lo(rd), lo(rs)), ctx);
>  		break;
>  	case BPF_DIV:
> -		emit(rv_divu(lo(rd), lo(rd), lo(rs)), ctx);
> +		if (is_sdiv)
> +			emit(rv_div(lo(rd), lo(rd), lo(rs)), ctx);
> +		else
> +			emit(rv_divu(lo(rd), lo(rd), lo(rs)), ctx);
>  		break;
>  	case BPF_MOD:
> -		emit(rv_remu(lo(rd), lo(rd), lo(rs)), ctx);
> +		if (is_sdiv)
> +			emit(rv_rem(lo(rd), lo(rd), lo(rs)), ctx);
> +		else
> +			emit(rv_remu(lo(rd), lo(rd), lo(rs)), ctx);
>  		break;
>  	case BPF_LSH:
>  		emit(rv_sll(lo(rd), lo(rd), lo(rs)), ctx);
> @@ -959,6 +965,7 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx,
>  	u8 code = insn->code;
>  	s16 off = insn->off;
>  	s32 imm = insn->imm;
> +	bool is_sdiv = false;
>
>  	const s8 *dst = bpf2rv32[insn->dst_reg];
>  	const s8 *src = bpf2rv32[insn->src_reg];
> @@ -1041,7 +1048,9 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx,
>  			emit_imm32(tmp2, imm, ctx);
>  			src = tmp2;
>  		}
> -		emit_alu_r32(dst, src, ctx, BPF_OP(code));
> +		if ((BPF_OP(code) == BPF_DIV || BPF_OP(code) == BPF_MOD) && insn->off == 1)
> +			is_sdiv = true;
> +		emit_alu_r32(dst, src, ctx, BPF_OP(code), is_sdiv);
>  		break;
>
>  	case BPF_ALU | BPF_MOV | BPF_K:
> @@ -1065,7 +1074,7 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx,
>  		 * src is ignored---choose tmp2 as a dummy register since it
>  		 * is not on the stack.
>  		 */
> -		emit_alu_r32(dst, tmp2, ctx, BPF_OP(code));
> +		emit_alu_r32(dst, tmp2, ctx, BPF_OP(code), false);
>  		break;
>
>  	case BPF_ALU | BPF_END | BPF_FROM_LE:


---
AI reviewed your patch. Please fix the bug or email reply why it's not a bug.
See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md

CI run summary: https://github.com/kernel-patches/bpf/actions/runs/25109627626