diff options
| author |   Martin KaFai Lau <kafai@fb.com> | 2019-11-07 10:09:05 -0800 |
|---|---|---|
| committer |   Alexei Starovoitov <ast@kernel.org> | 2019-11-07 10:59:08 -0800 |
| commit | ed5941af3f67ba9062b98aba1a6ca398867dc0de (patch) | |
| tree | b0b8bc736a595b0589e9a0feecf74fb615da0083 /tools/testing/selftests/bpf/progs/kfree_skb.c | |
| parent | bpf: Add array support to btf_struct_access (diff) | |
| download | linux-dev-ed5941af3f67ba9062b98aba1a6ca398867dc0de.tar.xz linux-dev-ed5941af3f67ba9062b98aba1a6ca398867dc0de.zip | |
bpf: Add cb access in kfree_skb test
Access the skb->cb[] in the kfree_skb test.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191107180905.4097871-1-kafai@fb.com
Diffstat (limited to '')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/kfree_skb.c | 25 |
1 files changed, 20 insertions, 5 deletions
diff --git a/tools/testing/selftests/bpf/progs/kfree_skb.c b/tools/testing/selftests/bpf/progs/kfree_skb.c index 489319ea1d6a..f769fdbf6725 100644 --- a/tools/testing/selftests/bpf/progs/kfree_skb.c +++ b/tools/testing/selftests/bpf/progs/kfree_skb.c @@ -43,6 +43,7 @@ struct sk_buff { refcount_t users; unsigned char *data; char __pkt_type_offset[0]; + char cb[48]; }; /* copy arguments from @@ -57,28 +58,41 @@ struct trace_kfree_skb { void *location; }; +struct meta { + int ifindex; + __u32 cb32_0; + __u8 cb8_0; +}; + SEC("tp_btf/kfree_skb") int trace_kfree_skb(struct trace_kfree_skb *ctx) { struct sk_buff *skb = ctx->skb; struct net_device *dev; - int ifindex; struct callback_head *ptr; void *func; int users; unsigned char *data; unsigned short pkt_data; + struct meta meta = {}; char pkt_type; + __u32 *cb32; + __u8 *cb8; __builtin_preserve_access_index(({ users = skb->users.refs.counter; data = skb->data; dev = skb->dev; - ifindex = dev->ifindex; ptr = dev->ifalias->rcuhead.next; func = ptr->func; + cb8 = (__u8 *)&skb->cb; + cb32 = (__u32 *)&skb->cb; })); + meta.ifindex = _(dev->ifindex); + meta.cb8_0 = cb8[8]; + meta.cb32_0 = cb32[2]; + bpf_probe_read_kernel(&pkt_type, sizeof(pkt_type), _(&skb->__pkt_type_offset)); pkt_type &= 7; @@ -90,14 +104,15 @@ int trace_kfree_skb(struct trace_kfree_skb *ctx) _(skb->len), users, pkt_type); bpf_printk("skb->queue_mapping %d\n", _(skb->queue_mapping)); bpf_printk("dev->ifindex %d data %llx pkt_data %x\n", - ifindex, data, pkt_data); + meta.ifindex, data, pkt_data); + bpf_printk("cb8_0:%x cb32_0:%x\n", meta.cb8_0, meta.cb32_0); - if (users != 1 || pkt_data != bpf_htons(0x86dd) || ifindex != 1) + if (users != 1 || pkt_data != bpf_htons(0x86dd) || meta.ifindex != 1) /* raw tp ignores return value */ return 0; /* send first 72 byte of the packet to user space */ bpf_skb_output(skb, &perf_buf_map, (72ull << 32) | BPF_F_CURRENT_CPU, - &ifindex, sizeof(ifindex)); + &meta, sizeof(meta)); return 0; } |