bpf, arm64: remove obsolete exception handling from div/mod

Since we've changed div/mod exception handling for src_reg in
eBPF verifier itself, remove the leftovers from arm64 JIT.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index 0775d5a..1d4f1da 100644 (file)
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c
@@ -390,18 +390,6 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx)
        case BPF_ALU64 | BPF_DIV | BPF_X:
        case BPF_ALU | BPF_MOD | BPF_X:
        case BPF_ALU64 | BPF_MOD | BPF_X:
-       {
-               const u8 r0 = bpf2a64[BPF_REG_0];
-
-               /* if (src == 0) return 0 */
-               jmp_offset = 3; /* skip ahead to else path */
-               check_imm19(jmp_offset);
-               emit(A64_CBNZ(is64, src, jmp_offset), ctx);
-               emit(A64_MOVZ(1, r0, 0, 0), ctx);
-               jmp_offset = epilogue_offset(ctx);
-               check_imm26(jmp_offset);
-               emit(A64_B(jmp_offset), ctx);
-               /* else */
                switch (BPF_OP(code)) {
                case BPF_DIV:
                        emit(A64_UDIV(is64, dst, dst, src), ctx);
@@ -413,7 +401,6 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx)
                        break;
                }
                break;
-       }
        case BPF_ALU | BPF_LSH | BPF_X:
        case BPF_ALU64 | BPF_LSH | BPF_X:
                emit(A64_LSLV(is64, dst, dst, src), ctx);