diff options
| -rw-r--r-- | arch/loongarch/net/bpf_jit.c | 37 |
1 files changed, 36 insertions, 1 deletions
diff --git a/arch/loongarch/net/bpf_jit.c b/arch/loongarch/net/bpf_jit.c index fa1a3234e9a6..cbe53d0b7fb0 100644 --- a/arch/loongarch/net/bpf_jit.c +++ b/arch/loongarch/net/bpf_jit.c @@ -1448,6 +1448,37 @@ void arch_free_bpf_trampoline(void *image, unsigned int size) bpf_prog_pack_free(image, size); } +/* + * Sign-extend the register if necessary + */ +static void sign_extend(struct jit_ctx *ctx, int rd, int rj, u8 size, bool sign) +{ + /* ABI requires unsigned char/short to be zero-extended */ + if (!sign && (size == 1 || size == 2)) { + if (rd != rj) + move_reg(ctx, rd, rj); + return; + } + + switch (size) { + case 1: + emit_insn(ctx, extwb, rd, rj); + break; + case 2: + emit_insn(ctx, extwh, rd, rj); + break; + case 4: + emit_insn(ctx, addiw, rd, rj, 0); + break; + case 8: + if (rd != rj) + move_reg(ctx, rd, rj); + break; + default: + pr_warn("bpf_jit: invalid size %d for sign_extend\n", size); + } +} + static int __arch_prepare_bpf_trampoline(struct jit_ctx *ctx, struct bpf_tramp_image *im, const struct btf_func_model *m, struct bpf_tramp_links *tlinks, void *func_addr, u32 flags) @@ -1655,8 +1686,12 @@ static int __arch_prepare_bpf_trampoline(struct jit_ctx *ctx, struct bpf_tramp_i restore_args(ctx, m->nr_args, args_off); if (save_ret) { - emit_insn(ctx, ldd, LOONGARCH_GPR_A0, LOONGARCH_GPR_FP, -retval_off); emit_insn(ctx, ldd, regmap[BPF_REG_0], LOONGARCH_GPR_FP, -(retval_off - 8)); + if (is_struct_ops) + sign_extend(ctx, LOONGARCH_GPR_A0, regmap[BPF_REG_0], + m->ret_size, m->ret_flags & BTF_FMODEL_SIGNED_ARG); + else + emit_insn(ctx, ldd, LOONGARCH_GPR_A0, LOONGARCH_GPR_FP, -retval_off); } emit_insn(ctx, ldd, LOONGARCH_GPR_S1, LOONGARCH_GPR_FP, -sreg_off); |