// SPDX-License-Identifier: GPL-2.0 /* Copyright Leon Hwang */ #include "vmlinux.h" #include <bpf/bpf_helpers.h> #include <bpf/bpf_tracing.h> struct { __uint(type, BPF_MAP_TYPE_PROG_ARRAY); __uint(max_entries, 1); __uint(key_size, sizeof(__u32)); __uint(value_size, sizeof(__u32)); } jmp_table SEC(".maps"); int count = 0; static __noinline int subprog_tail(void *ctx) { bpf_tail_call_static(ctx, &jmp_table, 0); return 0; } SEC("fentry/dummy") int BPF_PROG(fentry, struct sk_buff *skb) { count++; subprog_tail(ctx); subprog_tail(ctx); return 0; } char _license[] SEC("license") = "GPL";