MIPS: BPF: Add JIT support for SKF_AD_HATYPE.

This let's us pass some additional "modprobe test-bpf" tests with JIT
enabled.

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>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Steven J. Hill <steven.hill@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/15744/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

diff --git a/arch/mips/net/bpf_jit.c b/arch/mips/net/bpf_jit.c
index 49a2e2226fee84f2a284373a427b5fe155bf261d..880e329310ee8fc3226c4ff73322978d16270467 100644 (file)
--- a/arch/mips/net/bpf_jit.c
+++ b/arch/mips/net/bpf_jit.c
@@ -365,6 +365,12 @@ static inline void emit_half_load(unsigned int reg, unsigned int base,
        emit_instr(ctx, lh, reg, offset, base);
 }
 
+static inline void emit_half_load_unsigned(unsigned int reg, unsigned int base,
+                                          unsigned int offset, struct jit_ctx *ctx)
+{
+       emit_instr(ctx, lhu, reg, offset, base);
+}
+
 static inline void emit_mul(unsigned int dst, unsigned int src1,
                            unsigned int src2, struct jit_ctx *ctx)
 {
@@ -1112,6 +1118,8 @@ jmp_cmp:
                        break;
                case BPF_ANC | SKF_AD_IFINDEX:
                        /* A = skb->dev->ifindex */
+               case BPF_ANC | SKF_AD_HATYPE:
+                       /* A = skb->dev->type */
                        ctx->flags |= SEEN_SKB | SEEN_A;
                        off = offsetof(struct sk_buff, dev);
                        /* Load *dev pointer */
@@ -1120,10 +1128,15 @@ jmp_cmp:
                        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_unsigned(r_A, r_s0, off, ctx);
+                       }
                        break;
                case BPF_ANC | SKF_AD_MARK:
                        ctx->flags |= SEEN_SKB | SEEN_A;