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 260 |
9 | |
10 | static __attribute__ ((noinline)) |
11 | int f0(int var, struct __sk_buff *skb) |
12 | { |
13 | asm volatile ("" ); |
14 | |
15 | return skb->len; |
16 | } |
17 | |
18 | __attribute__ ((noinline)) |
19 | int f1(struct __sk_buff *skb) |
20 | { |
21 | volatile char buf[MAX_STACK] = {}; |
22 | |
23 | __sink(buf[MAX_STACK - 1]); |
24 | |
25 | return f0(var: 0, skb) + skb->len; |
26 | } |
27 | |
28 | int f3(int, struct __sk_buff *skb, int); |
29 | |
30 | __attribute__ ((noinline)) |
31 | int f2(int val, struct __sk_buff *skb) |
32 | { |
33 | volatile char buf[MAX_STACK] = {}; |
34 | |
35 | __sink(buf[MAX_STACK - 1]); |
36 | |
37 | return f1(skb) + f3(val, skb, 1); |
38 | } |
39 | |
40 | __attribute__ ((noinline)) |
41 | int f3(int val, struct __sk_buff *skb, int var) |
42 | { |
43 | volatile char buf[MAX_STACK] = {}; |
44 | |
45 | __sink(buf[MAX_STACK - 1]); |
46 | |
47 | return skb->ifindex * val * var; |
48 | } |
49 | |
50 | SEC("tc" ) |
51 | __failure __msg("combined stack size of 3 calls is" ) |
52 | int global_func1(struct __sk_buff *skb) |
53 | { |
54 | return f0(var: 1, skb) + f1(skb) + f2(val: 2, skb) + f3(val: 3, skb, var: 4); |
55 | } |
56 | |