diff options
| -rw-r--r-- | arch/x86/net/bpf_jit_comp.c | 21 |
1 files changed, 11 insertions, 10 deletions
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index f3e5cd8c1e68..9895ca383023 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -615,8 +615,10 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, case BPF_ALU | BPF_MUL | BPF_X: case BPF_ALU64 | BPF_MUL | BPF_K: case BPF_ALU64 | BPF_MUL | BPF_X: - EMIT1(0x50); /* push rax */ - EMIT1(0x52); /* push rdx */ + if (dst_reg != BPF_REG_0) + EMIT1(0x50); /* push rax */ + if (dst_reg != BPF_REG_3) + EMIT1(0x52); /* push rdx */ /* mov r11, dst_reg */ EMIT_mov(AUX_REG, dst_reg); @@ -636,14 +638,13 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, /* mul(q) r11 */ EMIT2(0xF7, add_1reg(0xE0, AUX_REG)); - /* mov r11, rax */ - EMIT_mov(AUX_REG, BPF_REG_0); - - EMIT1(0x5A); /* pop rdx */ - EMIT1(0x58); /* pop rax */ - - /* mov dst_reg, r11 */ - EMIT_mov(dst_reg, AUX_REG); + if (dst_reg != BPF_REG_3) + EMIT1(0x5A); /* pop rdx */ + if (dst_reg != BPF_REG_0) { + /* mov dst_reg, rax */ + EMIT_mov(dst_reg, BPF_REG_0); + EMIT1(0x58); /* pop rax */ + } break; /* shifts */ |