linux/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf1.c
Maciej Fijalkowski 3b03791111 selftests/bpf: Add tailcall_bpf2bpf tests
Add four tests to tailcalls selftest explicitly named
"tailcall_bpf2bpf_X" as their purpose is to validate that combination
of tailcalls with bpf2bpf calls are working properly.
These tests also validate LD_ABS from subprograms.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2020-09-17 19:56:07 -07:00

39 lines
728 B
C

// 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;