tools/testing/selftests/bpf/progs/loop1.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (c) 2019 Facebook
   3 #include <linux/sched.h>
   4 #include <linux/ptrace.h>
   5 #include <stdint.h>
   6 #include <stddef.h>
   7 #include <stdbool.h>
   8 #include <linux/bpf.h>
   9 #include <bpf/bpf_helpers.h>
  10 #include <bpf/bpf_tracing.h>
  11
  12 char _license[] SEC("license") = "GPL";
  13
  14 SEC("raw_tracepoint/kfree_skb")
  15 int nested_loops(volatile struct pt_regs* ctx)
  16 {
  17         int i, j, sum = 0, m;
  18
  19         for (j = 0; j < 300; j++)
  20                 for (i = 0; i < j; i++) {
  21                         if (j & 1)
  22                                 m = PT_REGS_RC(ctx);
  23                         else
  24                                 m = j;
  25                         sum += i * m;
  26                 }
  27
  28         return sum;
  29 }