x86: bpf_jit_comp: add XOR instruction for BPF JIT

This patch is a follow-up for patch "filter: add XOR instruction for use
with X/K" that implements BPF x86 JIT parts for the BPF XOR operation.

Signed-off-by: Daniel Borkmann <daniel.borkmann@tik.ee.ethz.ch>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index 106c578..520d2bd 100644 (file)
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -335,9 +335,18 @@ void bpf_jit_compile(struct sk_filter *fp)
                                        EMIT1_off32(0x0d, K);   /* or imm32,%eax */
                                break;
                        case BPF_S_ANC_ALU_XOR_X: /* A ^= X; */
+                       case BPF_S_ALU_XOR_X:
                                seen |= SEEN_XREG;
                                EMIT2(0x31, 0xd8);              /* xor %ebx,%eax */
                                break;
+                       case BPF_S_ALU_XOR_K: /* A ^= K; */
+                               if (K == 0)
+                                       break;
+                               if (is_imm8(K))
+                                       EMIT3(0x83, 0xf0, K);   /* xor imm8,%eax */
+                               else
+                                       EMIT1_off32(0x35, K);   /* xor imm32,%eax */
+                               break;
                        case BPF_S_ALU_LSH_X: /* A <<= X; */
                                seen |= SEEN_XREG;
                                EMIT4(0x89, 0xd9, 0xd3, 0xe0);  /* mov %ebx,%ecx; shl %cl,%eax */