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

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (c) 2019 Facebook
   3 #include <vmlinux.h>
   4 #include <linux/version.h>
   5 #include <bpf/bpf_helpers.h>
   6
   7 struct task_struct *bpf_task_from_pid(int pid) __ksym;
   8 void bpf_task_release(struct task_struct *p) __ksym;
   9 int bpf_send_signal_task(struct task_struct *task, int sig, enum pid_type type, u64 value) __ksym;
  10
  11 __u32 sig = 0, pid = 0, status = 0, signal_thread = 0, target_pid = 0;
  12
  13 static __always_inline int bpf_send_signal_test(void *ctx)
  14 {
  15         struct task_struct *target_task = NULL;
  16         int ret;
  17         u64 value;
  18
  19         if (status != 0 || pid == 0)
  20                 return 0;
  21
  22         if ((bpf_get_current_pid_tgid() >> 32) == pid) {
  23                 if (target_pid) {
  24                         target_task = bpf_task_from_pid(target_pid);
  25                         if (!target_task)
  26                                 return 0;
  27                         value = 8;
  28                 }
  29
  30                 if (signal_thread) {
  31                         if (target_pid)
  32                                 ret = bpf_send_signal_task(target_task, sig, PIDTYPE_PID, value);
  33                         else
  34                                 ret = bpf_send_signal_thread(sig);
  35                 } else {
  36                         if (target_pid)
  37                                 ret = bpf_send_signal_task(target_task, sig, PIDTYPE_TGID, value);
  38                         else
  39                                 ret = bpf_send_signal(sig);
  40                 }
  41                 if (ret == 0)
  42                         status = 1;
  43         }
  44
  45         if (target_task)
  46                 bpf_task_release(target_task);
  47
  48         return 0;
  49 }
  50
  51 SEC("tracepoint/syscalls/sys_enter_nanosleep")
  52 int send_signal_tp(void *ctx)
  53 {
  54         return bpf_send_signal_test(ctx);
  55 }
  56
  57 SEC("tracepoint/sched/sched_switch")
  58 int send_signal_tp_sched(void *ctx)
  59 {
  60         return bpf_send_signal_test(ctx);
  61 }
  62
  63 SEC("perf_event")
  64 int send_signal_perf(void *ctx)
  65 {
  66         return bpf_send_signal_test(ctx);
  67 }
  68
  69 char __license[] SEC("license") = "GPL";