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 | #include "bpf_misc.h" |
7 | |
8 | #define MAX_STACK (512 - 3 * 32) |
9 | |
10 | static __attribute__ ((noinline)) |
11 | int f0(int var, struct __sk_buff *skb) |
12 | { |
13 | return skb->len; |
14 | } |
15 | |
16 | __attribute__ ((noinline)) |
17 | int f1(struct __sk_buff *skb) |
18 | { |
19 | volatile char buf[MAX_STACK] = {}; |
20 | |
21 | __sink(buf[MAX_STACK - 1]); |
22 | |
23 | return f0(var: 0, skb) + skb->len; |
24 | } |
25 | |
26 | int f3(int, struct __sk_buff *skb, int); |
27 | |
28 | __attribute__ ((noinline)) |
29 | int f2(int val, struct __sk_buff *skb) |
30 | { |
31 | return f1(skb) + f3(val, skb, 1); |
32 | } |
33 | |
34 | __attribute__ ((noinline)) |
35 | int f3(int val, struct __sk_buff *skb, int var) |
36 | { |
37 | volatile char buf[MAX_STACK] = {}; |
38 | |
39 | __sink(buf[MAX_STACK - 1]); |
40 | |
41 | return skb->ifindex * val * var; |
42 | } |
43 | |
44 | SEC("tc" ) |
45 | __success |
46 | int global_func2(struct __sk_buff *skb) |
47 | { |
48 | return f0(var: 1, skb) + f1(skb) + f2(val: 2, skb) + f3(val: 3, skb, var: 4); |
49 | } |
50 | |