@@ -857,7 +857,9 @@ b_epilogue:
emit(ARM_LDR_I(r_A, r_scratch, off), ctx);
break;
case BPF_ANC | SKF_AD_IFINDEX:
+ case BPF_ANC | SKF_AD_HATYPE:
/* A = skb->dev->ifindex */
+ /* A = skb->dev->type */
ctx->seen |= SEEN_SKB;
off = offsetof(struct sk_buff, dev);
emit(ARM_LDR_I(r_scratch, r_skb, off), ctx);
@@ -867,8 +869,24 @@ b_epilogue:
BUILD_BUG_ON(FIELD_SIZEOF(struct net_device,
ifindex) != 4);
- off = offsetof(struct net_device, ifindex);
- emit(ARM_LDR_I(r_A, r_scratch, off), ctx);
+ BUILD_BUG_ON(FIELD_SIZEOF(struct net_device,
+ type) != 2);
+
+ if (code == (BPF_ANC | SKF_AD_IFINDEX)) {
+ off = offsetof(struct net_device, ifindex);
+ emit(ARM_LDR_I(r_A, r_scratch, off), ctx);
+ } else {
+ /*
+ * offset of field "type" in "struct
+ * net_device" is above what can be
+ * used in the ldrh rd, [rn, #imm]
+ * instruction, so load the offset in
+ * a register and use ldrh rd, [rn, rm]
+ */
+ off = offsetof(struct net_device, type);
+ emit_mov_i(ARM_R3, off, ctx);
+ emit(ARM_LDRH_R(r_A, r_scratch, ARM_R3), ctx);
+ }
break;
case BPF_ANC | SKF_AD_MARK:
ctx->seen |= SEEN_SKB;
@@ -74,6 +74,7 @@
#define ARM_INST_LDRB_I 0x05d00000
#define ARM_INST_LDRB_R 0x07d00000
#define ARM_INST_LDRH_I 0x01d000b0
+#define ARM_INST_LDRH_R 0x019000b0
#define ARM_INST_LDR_I 0x05900000
#define ARM_INST_LDM 0x08900000
@@ -160,6 +161,8 @@
| (rm))
#define ARM_LDRH_I(rt, rn, off) (ARM_INST_LDRH_I | (rt) << 12 | (rn) << 16 \
| (((off) & 0xf0) << 4) | ((off) & 0xf))
+#define ARM_LDRH_R(rt, rn, rm) (ARM_INST_LDRH_R | (rt) << 12 | (rn) << 16 \
+ | (rm))
#define ARM_LDM(rn, regs) (ARM_INST_LDM | (rn) << 16 | (regs))
Signed-off-by: Nicolas Schichan <nschichan@freebox.fr> --- arch/arm/net/bpf_jit_32.c | 22 ++++++++++++++++++++-- arch/arm/net/bpf_jit_32.h | 3 +++ 2 files changed, 23 insertions(+), 2 deletions(-)