Subject: [PATCH v2 2/2] powerpc: bpf: Fix the broken LD_VLAN_TAG_PRESENT test

From: Denis Kirjanov <[email-masked]>
Date: Wed, 25 Jun 2014 21:34:57 +0400

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 <[email-masked]>
---
 arch/powerpc/net/bpf_jit_comp.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c
index 892167b..82e82ca 100644
--- 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,
-- 
2.0.0