From c18fe54b3f8d7daa6a43270f82676d6a563582a4 Mon Sep 17 00:00:00 2001 From: Nicolas Schichan Date: Tue, 21 Jul 2015 14:14:14 +0200 Subject: [PATCH] ARM: net: fix vlan access instructions in ARM JIT. This makes BPF_ANC | SKF_AD_VLAN_TAG and BPF_ANC | SKF_AD_VLAN_TAG_PRESENT have the same behaviour as the in kernel VM and makes the test_bpf LD_VLAN_TAG and LD_VLAN_TAG_PRESENT tests pass. Signed-off-by: Nicolas Schichan Signed-off-by: David S. Miller --- arch/arm/net/bpf_jit_32.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c index d9b25242f743..c011e2296cb1 100644 --- a/arch/arm/net/bpf_jit_32.c +++ b/arch/arm/net/bpf_jit_32.c @@ -889,9 +889,11 @@ b_epilogue: off = offsetof(struct sk_buff, vlan_tci); emit(ARM_LDRH_I(r_A, r_skb, off), ctx); if (code == (BPF_ANC | SKF_AD_VLAN_TAG)) - OP_IMM3(ARM_AND, r_A, r_A, VLAN_VID_MASK, ctx); - else - OP_IMM3(ARM_AND, r_A, r_A, VLAN_TAG_PRESENT, ctx); + OP_IMM3(ARM_AND, r_A, r_A, ~VLAN_TAG_PRESENT, ctx); + else { + OP_IMM3(ARM_LSR, r_A, r_A, 12, ctx); + OP_IMM3(ARM_AND, r_A, r_A, 0x1, ctx); + } break; case BPF_ANC | SKF_AD_QUEUE: ctx->seen |= SEEN_SKB; -- 2.39.2