On 03/13/2017 03:56 AM, James Hogan wrote:
On Fri, Mar 10, 2017 at 02:14:05PM -0800, David Daney wrote:
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@xxxxxxxxxx>
I think the BPF maintainers should probably be Cc'd on this patch.
Cc'ing now.
Good point.
Since there are some corrections needed, I will send another version and
CC the proper people.
---
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 */
this comment should probably be updated.
Right.
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);
Technically net_device::type is unsigned, and emit_half_load uses LH
which sign extends. Does that matter in practice.
The next version will use LHU.
Cheers
James
