tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0-only
2/* Copyright (c) 2020 Facebook */
3#include <stddef.h>
4#include <linux/bpf.h>
5#include <bpf/bpf_helpers.h>
6
7#ifndef MAX_STACK
8#define MAX_STACK (512 - 3 * 32 + 8)
9#endif
10
11static __attribute__ ((noinline))
12int f0(int var, struct __sk_buff *skb)
13{
14 return skb->len;
15}
16
17__attribute__ ((noinline))
18int f1(struct __sk_buff *skb)
19{
20 volatile char buf[MAX_STACK] = {};
21
22 return f0(0, skb) + skb->len;
23}
24
25int f3(int, struct __sk_buff *skb, int);
26
27__attribute__ ((noinline))
28int f2(int val, struct __sk_buff *skb)
29{
30 return f1(skb) + f3(val, skb, 1);
31}
32
33__attribute__ ((noinline))
34int f3(int val, struct __sk_buff *skb, int var)
35{
36 volatile char buf[MAX_STACK] = {};
37
38 return skb->ifindex * val * var;
39}
40
41SEC("tc")
42int test_cls(struct __sk_buff *skb)
43{
44 return f0(1, skb) + f1(skb) + f2(2, skb) + f3(3, skb, 4);
45}