tools/testing/selftests/bpf/progs/tailcall6.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/bpf.h>
   3
   4 #include <bpf/bpf_helpers.h>
   5
   6 struct {
   7         __uint(type, BPF_MAP_TYPE_PROG_ARRAY);
   8         __uint(max_entries, 1);
   9         __uint(key_size, sizeof(__u32));
  10         __uint(value_size, sizeof(__u32));
  11 } jmp_table SEC(".maps");
  12
  13 int count, which;
  14
  15 SEC("tc")
  16 int classifier_0(struct __sk_buff *skb)
  17 {
  18         count++;
  19         if (__builtin_constant_p(which))
  20                 __bpf_unreachable();
  21         bpf_tail_call(skb, &jmp_table, which);
  22         return 1;
  23 }
  24
  25 SEC("tc")
  26 int entry(struct __sk_buff *skb)
  27 {
  28         if (__builtin_constant_p(which))
  29                 __bpf_unreachable();
  30         bpf_tail_call(skb, &jmp_table, which);
  31         return 0;
  32 }
  33
  34 char __license[] SEC("license") = "GPL";