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
bpf_send_signal_test(void * ctx)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")
send_signal_tp(void * ctx)52 int send_signal_tp(void *ctx)
53 {
54 return bpf_send_signal_test(ctx);
55 }
56
57 SEC("tracepoint/sched/sched_switch")
send_signal_tp_sched(void * ctx)58 int send_signal_tp_sched(void *ctx)
59 {
60 return bpf_send_signal_test(ctx);
61 }
62
63 SEC("perf_event")
send_signal_perf(void * ctx)64 int send_signal_perf(void *ctx)
65 {
66 return bpf_send_signal_test(ctx);
67 }
68
69 char __license[] SEC("license") = "GPL";
70