LXR linux/tools/testing/selftests/bpf/progs/tailcall2.c

   1// SPDX-License-Identifier: GPL-2.0
   2#include <linux/bpf.h>
   3
   4#include <bpf/bpf_helpers.h>
   5
   6struct {
   7        __uint(type, BPF_MAP_TYPE_PROG_ARRAY);
   8        __uint(max_entries, 5);
   9        __uint(key_size, sizeof(__u32));
  10        __uint(value_size, sizeof(__u32));
  11} jmp_table SEC(".maps");
  12
  13SEC("classifier/0")
  14int bpf_func_0(struct __sk_buff *skb)
  15{
  16        bpf_tail_call_static(skb, &jmp_table, 1);
  17        return 0;
  18}
  19
  20SEC("classifier/1")
  21int bpf_func_1(struct __sk_buff *skb)
  22{
  23        bpf_tail_call_static(skb, &jmp_table, 2);
  24        return 1;
  25}
  26
  27SEC("classifier/2")
  28int bpf_func_2(struct __sk_buff *skb)
  29{
  30        return 2;
  31}
  32
  33SEC("classifier/3")
  34int bpf_func_3(struct __sk_buff *skb)
  35{
  36        bpf_tail_call_static(skb, &jmp_table, 4);
  37        return 3;
  38}
  39
  40SEC("classifier/4")
  41int bpf_func_4(struct __sk_buff *skb)
  42{
  43        bpf_tail_call_static(skb, &jmp_table, 3);
  44        return 4;
  45}
  46
  47SEC("classifier")
  48int entry(struct __sk_buff *skb)
  49{
  50        bpf_tail_call_static(skb, &jmp_table, 0);
  51        /* Check multi-prog update. */
  52        bpf_tail_call_static(skb, &jmp_table, 2);
  53        /* Check tail call limit. */
  54        bpf_tail_call_static(skb, &jmp_table, 3);
  55        return 3;
  56}
  57
  58char __license[] SEC("license") = "GPL";
  59int _version SEC("version") = 1;
  60