From: David Daney <david.daney@cavium.com>
To: linux-mips@linux-mips.org, ralf@linux-mips.org,
        James Hogan <james.hogan@imgtec.com>
Cc: linux-kernel@vger.kernel.org,
        "Steven J. Hill" <steven.hill@cavium.com>,
        David Daney <david.daney@cavium.com>
Subject: [PATCH] MIPS: BPF: Add support for SKF_AD_HATYPE
Date: Fri, 10 Mar 2017 14:14:05 -0800
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This let's us pass some additional "modprobe test-bpf" tests.

Reuse the code for SKF_AD_IFINDEX, but substitute the offset and size
of the "type" field.

Signed-off-by: David Daney <david.daney@cavium.com>
---
 arch/mips/net/bpf_jit.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/arch/mips/net/bpf_jit.c b/arch/mips/net/bpf_jit.c
index 49a2e22..f613708 100644
--- a/arch/mips/net/bpf_jit.c
+++ b/arch/mips/net/bpf_jit.c
@@ -1111,6 +1111,7 @@ static int build_body(struct jit_ctx *ctx)
 			emit_load(r_A, 28, off, ctx);
 			break;
 		case BPF_ANC | SKF_AD_IFINDEX:
+		case BPF_ANC | SKF_AD_HATYPE:
 			/* A = skb->dev->ifindex */
 			ctx->flags |= SEEN_SKB | SEEN_A;
 			off = offsetof(struct sk_buff, dev);
@@ -1120,10 +1121,15 @@ static int build_body(struct jit_ctx *ctx)
 			emit_bcond(MIPS_COND_EQ, r_s0, r_zero,
 				   b_imm(prog->len, ctx), ctx);
 			emit_reg_move(r_ret, r_zero, ctx);
-			BUILD_BUG_ON(FIELD_SIZEOF(struct net_device,
-						  ifindex) != 4);
-			off = offsetof(struct net_device, ifindex);
-			emit_load(r_A, r_s0, off, ctx);
+			if (code == (BPF_ANC | SKF_AD_IFINDEX)) {
+				BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4);
+				off = offsetof(struct net_device, ifindex);
+				emit_load(r_A, r_s0, off, ctx);
+			} else { /* (code == (BPF_ANC | SKF_AD_HATYPE) */
+				BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, type) != 2);
+				off = offsetof(struct net_device, type);
+				emit_half_load(r_A, r_s0, off, ctx);
+			}
 			break;
 		case BPF_ANC | SKF_AD_MARK:
 			ctx->flags |= SEEN_SKB | SEEN_A;
-- 
2.9.3