x86 bpf_jit: support BPF_S_ANC_ALU_XOR_X instruction

commit ffe06c17afbb  (filter: add XOR operation) added generic support
for XOR operation.

This patch implements the XOR instruction in x86 jit.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jiri Pirko <jpirko@redhat.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 0597f95..33643a8 100644 (file)
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -309,6 +309,10 @@ void bpf_jit_compile(struct sk_filter *fp)
                                else
                                        EMIT1_off32(0x0d, K);   /* or imm32,%eax */
                                break;
+                       case BPF_S_ANC_ALU_XOR_X: /* A ^= X; */
+                               seen |= SEEN_XREG;
+                               EMIT2(0x31, 0xd8);              /* xor %ebx,%eax */
+                               break;
                        case BPF_S_ALU_LSH_X: /* A <<= X; */
                                seen |= SEEN_XREG;
                                EMIT4(0x89, 0xd9, 0xd3, 0xe0);  /* mov %ebx,%ecx; shl %cl,%eax */