[PATCH bpf-next 6/7] bpf, arm64: Support signed div/mod instructions

Xu Kuohai
2023-08-15T15:21:15Z

Add jit for signed div/mod instructions.

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
---
arch/arm64/net/bpf_jit.h | 1 +
arch/arm64/net/bpf_jit_comp.c | 20 ++++++++++++++++----
2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/net/bpf_jit.h b/arch/arm64/net/bpf_jit.h
index 949810a0c48c..23b1b34db088 100644
--- a/arch/arm64/net/bpf_jit.h
+++ b/arch/arm64/net/bpf_jit.h
@@ -234,6 +234,7 @@
#define A64_DATA2(sf, Rd, Rn, Rm, type) aarch64_insn_gen_data2(Rd, Rn, Rm, \
A64_VARIANT(sf), AARCH64_INSN_DATA2_##type)
#define A64_UDIV(sf, Rd, Rn, Rm) A64_DATA2(sf, Rd, Rn, Rm, UDIV)
+#define A64_SDIV(sf, Rd, Rn, Rm) A64_DATA2(sf, Rd, Rn, Rm, SDIV)
#define A64_LSLV(sf, Rd, Rn, Rm) A64_DATA2(sf, Rd, Rn, Rm, LSLV)
#define A64_LSRV(sf, Rd, Rn, Rm) A64_DATA2(sf, Rd, Rn, Rm, LSRV)
#define A64_ASRV(sf, Rd, Rn, Rm) A64_DATA2(sf, Rd, Rn, Rm, ASRV)
diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index 924b8ef2e46a..150d1c6543f7 100644
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c
@@ -828,11 +828,17 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
break;
case BPF_ALU | BPF_DIV | BPF_X:
case BPF_ALU64 | BPF_DIV | BPF_X:
- emit(A64_UDIV(is64, dst, dst, src), ctx);
+ if (!off)
+ emit(A64_UDIV(is64, dst, dst, src), ctx);
+ else
+ emit(A64_SDIV(is64, dst, dst, src), ctx);
break;
case BPF_ALU | BPF_MOD | BPF_X:
case BPF_ALU64 | BPF_MOD | BPF_X:
- emit(A64_UDIV(is64, tmp, dst, src), ctx);
+ if (!off)
+ emit(A64_UDIV(is64, tmp, dst, src), ctx);
+ else
+ emit(A64_SDIV(is64, tmp, dst, src), ctx);
emit(A64_MSUB(is64, dst, dst, tmp, src), ctx);
break;
case BPF_ALU | BPF_LSH | BPF_X:
@@ -959,12 +965,18 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
case BPF_ALU | BPF_DIV | BPF_K:
case BPF_ALU64 | BPF_DIV | BPF_K:
emit_a64_mov_i(is64, tmp, imm, ctx);
- emit(A64_UDIV(is64, dst, dst, tmp), ctx);
+ if (!off)
+ emit(A64_UDIV(is64, dst, dst, tmp), ctx);
+ else
+ emit(A64_SDIV(is64, dst, dst, tmp), ctx);
break;
case BPF_ALU | BPF_MOD | BPF_K:
case BPF_ALU64 | BPF_MOD | BPF_K:
emit_a64_mov_i(is64, tmp2, imm, ctx);
- emit(A64_UDIV(is64, tmp, dst, tmp2), ctx);
+ if (!off)
+ emit(A64_UDIV(is64, tmp, dst, tmp2), ctx);
+ else
+ emit(A64_SDIV(is64, tmp, dst, tmp2), ctx);
emit(A64_MSUB(is64, dst, dst, tmp, tmp2), ctx);
break;
case BPF_ALU | BPF_LSH | BPF_K:
--
2.30.2