tools/testing/selftests/bpf/progs/test_global_func1.c

   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))
  12 int f0(int var, struct __sk_buff *skb)
  13 {
  14         return skb->len;
  15 }
  16
  17 __attribute__ ((noinline))
  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))
  28 int f2(int val, struct __sk_buff *skb)
  29 {
  30         return f1(skb) + f3(val, skb, 1);
  31 }
  32
  33 __attribute__ ((noinline))
  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("classifier/test")
  42 int test_cls(struct __sk_buff *skb)
  43 {
  44         return f0(1, skb) + f1(skb) + f2(2, skb) + f3(3, skb, 4);
  45 }