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

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (c) 2020 Tessares SA <http://www.tessares.net> */
   3
   4 #include "vmlinux.h"
   5 #include <bpf/bpf_helpers.h>
   6
   7 __u64 inKey = 0;
   8 __u64 inValue = 0;
   9 __u32 inPid = 0;
  10
  11 struct {
  12         __uint(type, BPF_MAP_TYPE_PERCPU_HASH);
  13         __uint(max_entries, 2);
  14         __type(key, __u64);
  15         __type(value, __u64);
  16 } hashmap1 SEC(".maps");
  17
  18
  19 SEC("tp/syscalls/sys_enter_getpgid")
  20 int sysenter_getpgid(const void *ctx)
  21 {
  22         /* Just do it for once, when called from our own test prog. This
  23          * ensures the map value is only updated for a single CPU.
  24          */
  25         int cur_pid = bpf_get_current_pid_tgid() >> 32;
  26
  27         if (cur_pid == inPid)
  28                 bpf_map_update_elem(&hashmap1, &inKey, &inValue, BPF_NOEXIST);
  29
  30         return 0;
  31 }
  32
  33 char _license[] SEC("license") = "GPL";