| // SPDX-License-Identifier: GPL-2.0-only |
| /* Copyright (c) 2020 Facebook */ |
| #include <stddef.h> |
| #include <linux/bpf.h> |
| #include <bpf/bpf_helpers.h> |
| #include "bpf_misc.h" |
| |
| #define MAX_STACK (512 - 3 * 32 + 8) |
| |
| static __attribute__ ((noinline)) |
| int f0(int var, struct __sk_buff *skb) |
| { |
| return skb->len; |
| } |
| |
| __attribute__ ((noinline)) |
| int f1(struct __sk_buff *skb) |
| { |
| volatile char buf[MAX_STACK] = {}; |
| |
| return f0(0, skb) + skb->len; |
| } |
| |
| int f3(int, struct __sk_buff *skb, int); |
| |
| __attribute__ ((noinline)) |
| int f2(int val, struct __sk_buff *skb) |
| { |
| return f1(skb) + f3(val, skb, 1); |
| } |
| |
| __attribute__ ((noinline)) |
| int f3(int val, struct __sk_buff *skb, int var) |
| { |
| volatile char buf[MAX_STACK] = {}; |
| |
| return skb->ifindex * val * var; |
| } |
| |
| SEC("tc") |
| __failure __msg("combined stack size of 4 calls is 544") |
| int global_func1(struct __sk_buff *skb) |
| { |
| return f0(1, skb) + f1(skb) + f2(2, skb) + f3(3, skb, 4); |
| } |