[PATCH v2 3/5] MIPS: BPF: Use unsigned access for unsigned SKB fields.
From: David Daney <hidden>
Date: 2017-03-14 21:22:12
Also in:
lkml, netdev
Subsystem:
bpf jit for mips (32-bit and 64-bit), bpf [general] (safe dynamic programs and tools), mips, the rest · Maintainers:
Johan Almbladh, Paul Burton, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Thomas Bogendoerfer, Linus Torvalds
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 <redacted> --- 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