Subject: [PATCH v2 bpf-next 15/17] selftests/bpf: Extend test_pkt_access test

From: Alexei Starovoitov <[email-masked]>
Date: Wed, 6 Nov 2019 21:46:42 -0800

The test_pkt_access.o is used by multiple tests. Fix its section name so that
program type can be automatically detected by libbpf and make it call another
subprogram with skb argument.

Signed-off-by: Alexei Starovoitov <[email-masked]>
---
 tools/testing/selftests/bpf/progs/test_pkt_access.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/test_pkt_access.c b/tools/testing/selftests/bpf/progs/test_pkt_access.c
index 7cf42d14103f..9aaee1400c1e 100644
--- a/tools/testing/selftests/bpf/progs/test_pkt_access.c
+++ b/tools/testing/selftests/bpf/progs/test_pkt_access.c
@@ -17,8 +17,14 @@
 #define barrier() __asm__ __volatile__("": : :"memory")
 int _version SEC("version") = 1;
 
-SEC("test1")
-int process(struct __sk_buff *skb)
+static __attribute__ ((noinline))
+int test_pkt_access_subprog(volatile struct __sk_buff *skb)
+{
+	return skb->len * 2;
+}
+
+SEC("classifier/test_pkt_access")
+int test_pkt_access(struct __sk_buff *skb)
 {
 	void *data_end = (void *)(long)skb->data_end;
 	void *data = (void *)(long)skb->data;
@@ -48,6 +54,8 @@ int process(struct __sk_buff *skb)
 		tcp = (struct tcphdr *)((void *)(ip6h) + ihl_len);
 	}
 
+	if (test_pkt_access_subprog(skb) != skb->len * 2)
+		return TC_ACT_SHOT;
 	if (tcp) {
 		if (((void *)(tcp) + 20) > data_end || proto != 6)
 			return TC_ACT_SHOT;
-- 
2.23.0