diff options
| -rw-r--r-- | arch/riscv/net/bpf_jit_comp64.c | 42 |
1 files changed, 41 insertions, 1 deletions
diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c index 886b647dc206..14d7aab61fcb 100644 --- a/arch/riscv/net/bpf_jit_comp64.c +++ b/arch/riscv/net/bpf_jit_comp64.c @@ -711,6 +711,39 @@ static int emit_atomic_rmw(u8 rd, u8 rs, const struct bpf_insn *insn, return 0; } +/* + * Sign-extend the register if necessary + */ +static int sign_extend(u8 rd, u8 rs, u8 sz, bool sign, struct rv_jit_context *ctx) +{ + if (!sign && (sz == 1 || sz == 2)) { + if (rd != rs) + emit_mv(rd, rs, ctx); + return 0; + } + + switch (sz) { + case 1: + emit_sextb(rd, rs, ctx); + break; + case 2: + emit_sexth(rd, rs, ctx); + break; + case 4: + emit_sextw(rd, rs, ctx); + break; + case 8: + if (rd != rs) + emit_mv(rd, rs, ctx); + break; + default: + pr_err("bpf-jit: invalid size %d for sign_extend\n", sz); + return -EINVAL; + } + + return 0; +} + #define BPF_FIXUP_OFFSET_MASK GENMASK(26, 0) #define BPF_FIXUP_REG_MASK GENMASK(31, 27) #define REG_DONT_CLEAR_MARKER 0 /* RV_REG_ZERO unused in pt_regmap */ @@ -1175,8 +1208,15 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, restore_args(min_t(int, nr_arg_slots, RV_MAX_REG_ARGS), args_off, ctx); if (save_ret) { - emit_ld(RV_REG_A0, -retval_off, RV_REG_FP, ctx); emit_ld(regmap[BPF_REG_0], -(retval_off - 8), RV_REG_FP, ctx); + if (is_struct_ops) { + ret = sign_extend(RV_REG_A0, regmap[BPF_REG_0], m->ret_size, + m->ret_flags & BTF_FMODEL_SIGNED_ARG, ctx); + if (ret) + goto out; + } else { + emit_ld(RV_REG_A0, -retval_off, RV_REG_FP, ctx); + } } emit_ld(RV_REG_S1, -sreg_off, RV_REG_FP, ctx); |