[PATCH bpf-next v3 1/3] riscv, bpf: Add support for BPF_SDIV and BPF_SMOD in RV32 JIT

[Pu Lehui]

On 2026/7/7 2:12, bot+bpf-ci at kernel.org wrote:
>> commit c5a973b7fc82eeb9b84aaf80fc2673a94ab795b2
>> Author: Kuan-Wei Chiu <visitorckw at gmail.com>
>>
>>      riscv, bpf: Add support for BPF_SDIV and BPF_SMOD in RV32 JIT
>>
>>      The current rv32 bpf jit compiler incorrectly treats BPF_SDIV and
>>      BPF_SMOD as unsigned operations. The BPF instruction set allows
>>      signed division and modulo by reusing the BPF_DIV and BPF_MOD opcodes
>>      with the instruction offset set to 1.
>>
>>      Update the emit_alu_r32() function to accept an 'is_sdiv' variable and
>>      emit the correct div and rem instructions when the offset is 1.
>>
>>      Before this patch:
>>      [   44.161771] test_bpf: #165 ALU_SDIV_X: -6 / 2 = -3 jited:1 ret 2147483645 != -3 (0x7ffffffd != 0xfffffffd)FAIL (1 times)
>>      [   44.167385] test_bpf: #166 ALU_SDIV_K: -6 / 2 = -3 jited:1 ret 2147483645 != -3 (0x7ffffffd != 0xfffffffd)FAIL (1 times)
>>      [   44.171053] test_bpf: #169 ALU_SMOD_X: -7 % 2 = -1 jited:1 ret 1 != -1 (0x1 != 0xffffffff)FAIL (1 times)
>>      [   44.172081] test_bpf: #170 ALU_SMOD_K: -7 % 2 = -1 jited:1 ret 1 != -1 (0x1 != 0xffffffff)FAIL (1 times)
>>
>>      After this patch:
>>      [   16.002192] test_bpf: #165 ALU_SDIV_X: -6 / 2 = -3 jited:1 95 PASS
>>      [   16.002983] test_bpf: #166 ALU_SDIV_K: -6 / 2 = -3 jited:1 1059 PASS
>>      [   16.017167] test_bpf: #169 ALU_SMOD_X: -7 % 2 = -1 jited:1 136 PASS
>>      [   16.023002] test_bpf: #170 ALU_SMOD_K: -7 % 2 = -1 jited:1 109 PASS
>>
>>      Signed-off-by: Kuan-Wei Chiu <visitorckw at gmail.com>
> 
> This looks like a bug fix for the original RV32 BPF JIT implementation.
> Should this include:
> 
>    Fixes: 5f316b65e99f ("riscv, bpf: Add RV32G eBPF JIT")

not need to add fixes tag, as this not a bugfix

> 
> 
> ---
> 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/28811594040