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
11 static __attribute__ ((noinline))
f0(int var,struct __sk_buff * skb)12 int f0(int var, struct __sk_buff *skb)
13 {
14 return skb->len;
15 }
16
17 __attribute__ ((noinline))
f1(struct __sk_buff * skb)18 int f1(struct __sk_buff *skb)
19 {
20 volatile char buf[MAX_STACK] = {};
21
22 return f0(0, skb) + skb->len;
23 }
24
25 int f3(int, struct __sk_buff *skb, int);
26
27 __attribute__ ((noinline))
f2(int val,struct __sk_buff * skb)28 int f2(int val, struct __sk_buff *skb)
29 {
30 return f1(skb) + f3(val, skb, 1);
31 }
32
33 __attribute__ ((noinline))
f3(int val,struct __sk_buff * skb,int var)34 int 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
41 SEC("tc")
test_cls(struct __sk_buff * skb)42 int test_cls(struct __sk_buff *skb)
43 {
44 return f0(1, skb) + f1(skb) + f2(2, skb) + f3(3, skb, 4);
45 }
46