Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Alexei Starovoitov says:

====================
pull-request: bpf-next 2020-09-23

The following pull-request contains BPF updates for your *net-next* tree.

We've added 95 non-merge commits during the last 22 day(s) which contain
a total of 124 files changed, 4211 insertions(+), 2040 deletions(-).

The main changes are:

1) Full multi function support in libbpf, from Andrii.

2) Refactoring of function argument checks, from Lorenz.

3) Make bpf_tail_call compatible with functions (subprograms), from Maciej.

4) Program metadata support, from YiFei.

5) bpf iterator optimizations, from Yonghong.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 38 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf1.c b/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf1.c
new file mode 100644
index 000000000000..b5d9c8e778ae
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf1.c
@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
+	__uint(max_entries, 2);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(__u32));
+} jmp_table SEC(".maps");
+
+#define TAIL_FUNC(x) 				\
+	SEC("classifier/" #x)			\
+	int bpf_func_##x(struct __sk_buff *skb)	\
+	{					\
+		return x;			\
+	}
+TAIL_FUNC(0)
+TAIL_FUNC(1)
+
+static __noinline
+int subprog_tail(struct __sk_buff *skb)
+{
+	bpf_tail_call(skb, &jmp_table, 0);
+
+	return skb->len * 2;
+}
+
+SEC("classifier")
+int entry(struct __sk_buff *skb)
+{
+	bpf_tail_call(skb, &jmp_table, 1);
+
+	return subprog_tail(skb);
+}
+
+char __license[] SEC("license") = "GPL";
+int _version SEC("version") = 1;