[PATCH v2 3/5] MIPS: BPF: Use unsigned access for unsigned SKB fields.

From: David Daney
Date: Tue Mar 14 2017 - 17:22:16 EST


The SKB vlan_tci and queue_mapping fields are unsigned, don't sign
extend these in the BPF JIT. In the vlan_tci case, the value gets
masked so the change is not needed for correctness, but do it anyway
for agreement with the types defined in struct sk_buff.

Signed-off-by: David Daney <david.daney@xxxxxxxxxx>
---
arch/mips/net/bpf_jit.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/mips/net/bpf_jit.c b/arch/mips/net/bpf_jit.c
index 880e329..a68cd36 100644
--- a/arch/mips/net/bpf_jit.c
+++ b/arch/mips/net/bpf_jit.c
@@ -1156,7 +1156,7 @@ static int build_body(struct jit_ctx *ctx)
BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff,
vlan_tci) != 2);
off = offsetof(struct sk_buff, vlan_tci);
- emit_half_load(r_s0, r_skb, off, ctx);
+ emit_half_load_unsigned(r_s0, r_skb, off, ctx);
if (code == (BPF_ANC | SKF_AD_VLAN_TAG)) {
emit_andi(r_A, r_s0, (u16)~VLAN_TAG_PRESENT, ctx);
} else {
@@ -1183,7 +1183,7 @@ static int build_body(struct jit_ctx *ctx)
BUILD_BUG_ON(offsetof(struct sk_buff,
queue_mapping) > 0xff);
off = offsetof(struct sk_buff, queue_mapping);
- emit_half_load(r_A, r_skb, off, ctx);
+ emit_half_load_unsigned(r_A, r_skb, off, ctx);
break;
default:
pr_debug("%s: Unhandled opcode: 0x%02x\n", __FILE__,
--
2.9.3