riscv, bpf: Support sign-extension mov insns

Add support sign-extension mov instructions for RV64.

Signed-off-by: Pu Lehui <pulehui@huawei.com>
Acked-by: Björn Töpel <bjorn@kernel.org>
Link: https://lore.kernel.org/r/20230824095001.3408573-4-pulehui@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c
index fd36cb1..bcf1e75 100644 (file)
--- a/arch/riscv/net/bpf_jit_comp64.c
+++ b/arch/riscv/net/bpf_jit_comp64.c
@@ -1047,7 +1047,19 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx,
                        emit_zext_32(rd, ctx);
                        break;
                }
-               emit_mv(rd, rs, ctx);
+               switch (insn->off) {
+               case 0:
+                       emit_mv(rd, rs, ctx);
+                       break;
+               case 8:
+               case 16:
+                       emit_slli(RV_REG_T1, rs, 64 - insn->off, ctx);
+                       emit_srai(rd, RV_REG_T1, 64 - insn->off, ctx);
+                       break;
+               case 32:
+                       emit_addiw(rd, rs, 0, ctx);
+                       break;
+               }
                if (!is64 && !aux->verifier_zext)
                        emit_zext_32(rd, ctx);
                break;