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

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (c) 2019 Facebook
   3 #include <linux/bpf.h>
   4 #include <linux/version.h>
   5 #include "bpf_helpers.h"
   6
   7 struct {
   8         __uint(type, BPF_MAP_TYPE_ARRAY);
   9         __uint(max_entries, 1);
  10         __type(key, __u32);
  11         __type(value, __u64);
  12 } info_map SEC(".maps");
  13
  14 struct {
  15         __uint(type, BPF_MAP_TYPE_ARRAY);
  16         __uint(max_entries, 1);
  17         __type(key, __u32);
  18         __type(value, __u64);
  19 } status_map SEC(".maps");
  20
  21 SEC("send_signal_demo")
  22 int bpf_send_signal_test(void *ctx)
  23 {
  24         __u64 *info_val, *status_val;
  25         __u32 key = 0, pid, sig;
  26         int ret;
  27
  28         status_val = bpf_map_lookup_elem(&status_map, &key);
  29         if (!status_val || *status_val != 0)
  30                 return 0;
  31
  32         info_val = bpf_map_lookup_elem(&info_map, &key);
  33         if (!info_val || *info_val == 0)
  34                 return 0;
  35
  36         sig = *info_val >> 32;
  37         pid = *info_val & 0xffffFFFF;
  38
  39         if ((bpf_get_current_pid_tgid() >> 32) == pid) {
  40                 ret = bpf_send_signal(sig);
  41                 if (ret == 0)
  42                         *status_val = 1;
  43         }
  44
  45         return 0;
  46 }
  47 char __license[] SEC("license") = "GPL";