1// SPDX-License-Identifier: GPL-2.0
2// Copyright (c) 2019 Facebook
3#include <linux/sched.h>
4#include <linux/ptrace.h>
5#include <stdint.h>
6#include <stddef.h>
7#include <stdbool.h>
8#include <linux/bpf.h>
9#include <bpf/bpf_helpers.h>
10#include <bpf/bpf_tracing.h>
11
12char _license[] SEC("license") = "GPL";
13
14SEC("raw_tracepoint/consume_skb")
15int while_true(struct pt_regs *ctx)
16{
17 volatile __u64 i = 0, sum = 0;
18 do {
19 i++;
20 sum += PT_REGS_RC(ctx);
21 } while (i < 0x100000000ULL);
22 return sum;
23}
24

source code of linux/tools/testing/selftests/bpf/progs/loop3.c