powerpc: bpf: Fix the broken LD_VLAN_TAG_PRESENT test

We have to return the boolean here if the tag presents
or not, not just ANDing the TCI with the mask which results to:

[  709.412097] test_bpf: #18 LD_VLAN_TAG_PRESENT
[  709.412245] ret 4096 != 1
[  709.412332] ret 4096 != 1
[  709.412333] FAIL (2 times)

Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c
index 892167b..82e82ca 100644 (file)
--- a/arch/powerpc/net/bpf_jit_comp.c
+++ b/arch/powerpc/net/bpf_jit_comp.c
@@ -394,10 +394,12 @@ static int bpf_jit_build_body(struct sk_filter *fp, u32 *image,
 
                        PPC_LHZ_OFFS(r_A, r_skb, offsetof(struct sk_buff,
                                                          vlan_tci));
-                       if (code == (BPF_ANC | SKF_AD_VLAN_TAG))
+                       if (code == (BPF_ANC | SKF_AD_VLAN_TAG)) {
                                PPC_ANDI(r_A, r_A, ~VLAN_TAG_PRESENT);
-                       else
+                       } else {
                                PPC_ANDI(r_A, r_A, VLAN_TAG_PRESENT);
+                               PPC_SRWI(r_A, r_A, 12);
+                       }
                        break;
                case BPF_ANC | SKF_AD_QUEUE:
                        BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff,