LXR linux/tools/testing/selftests/bpf/progs/test_map

   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
  11struct {
  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
  19SEC("tp/syscalls/sys_enter_getpgid")
  20int 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
  33char _license[] SEC("license") = "GPL";
  34