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1// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
2/* Copyright (c) 2020 Facebook */
3#include "vmlinux.h"
4#include <bpf/bpf_helpers.h>
5#include <bpf/bpf_tracing.h>
6#include <bpf/bpf_core_read.h>
7#include "bootstrap.h"
8
9char LICENSE[] SEC("license") = "Dual BSD/GPL";
10
11struct {
12 __uint(type, BPF_MAP_TYPE_HASH);
13 __uint(max_entries, 8192);
14 __type(key, pid_t);
15 __type(value, u64);
16} exec_start SEC(".maps");
17
18struct {
19 __uint(type, BPF_MAP_TYPE_RINGBUF);
20 __uint(max_entries, 256 * 1024);
21} rb SEC(".maps");
22
23const volatile unsigned long long min_duration_ns = 0;
24
25SEC("tp/sched/sched_process_exec")
26int handle_exec(struct trace_event_raw_sched_process_exec *ctx)
27{
28 struct task_struct *task;
29 unsigned fname_off;
30 struct event *e;
31 pid_t pid;
32 u64 ts;
33
34 /* remember time exec() was executed for this PID */
35 pid = bpf_get_current_pid_tgid() >> 32;
36 ts = bpf_ktime_get_ns();
37 bpf_map_update_elem(&exec_start, &pid, &ts, BPF_ANY);
38
39 /* don't emit exec events when minimum duration is specified */
40 if (min_duration_ns)
41 return 0;
42
43 /* reserve sample from BPF ringbuf */
44 e = bpf_ringbuf_reserve(&rb, sizeof(*e), 0);
45 if (!e)
46 return 0;
47
48 /* fill out the sample with data */
49 task = (struct task_struct *)bpf_get_current_task();
50
51 e->exit_event = false;
52 e->pid = pid;
53 e->ppid = BPF_CORE_READ(task, real_parent, tgid);
54 bpf_get_current_comm(&e->comm, sizeof(e->comm));
55
56 fname_off = ctx->__data_loc_filename & 0xFFFF;
57 bpf_probe_read_str(&e->filename, sizeof(e->filename), (void *)ctx + fname_off);
58
59 /* successfully submit it to user-space for post-processing */
60 bpf_ringbuf_submit(e, 0);
61 return 0;
62}
63
64SEC("tp/sched/sched_process_exit")
65int handle_exit(struct trace_event_raw_sched_process_template *ctx)
66{
67 struct task_struct *task;
68 struct event *e;
69 pid_t pid, tid;
70 u64 id, ts, *start_ts, duration_ns = 0;
71
72 /* get PID and TID of exiting thread/process */
73 id = bpf_get_current_pid_tgid();
74 pid = id >> 32;
75 tid = (u32)id;
76
77 /* ignore thread exits */
78 if (pid != tid)
79 return 0;
80
81 /* if we recorded start of the process, calculate lifetime duration */
82 start_ts = bpf_map_lookup_elem(&exec_start, &pid);
83 if (start_ts)
84 duration_ns = bpf_ktime_get_ns() - *start_ts;
85 else if (min_duration_ns)
86 return 0;
87 bpf_map_delete_elem(&exec_start, &pid);
88
89 /* if process didn't live long enough, return early */
90 if (min_duration_ns && duration_ns < min_duration_ns)
91 return 0;
92
93 /* reserve sample from BPF ringbuf */
94 e = bpf_ringbuf_reserve(&rb, sizeof(*e), 0);
95 if (!e)
96 return 0;
97
98 /* fill out the sample with data */
99 task = (struct task_struct *)bpf_get_current_task();
100
101 e->exit_event = true;
102 e->duration_ns = duration_ns;
103 e->pid = pid;
104 e->ppid = BPF_CORE_READ(task, real_parent, tgid);
105 e->exit_code = (BPF_CORE_READ(task, exit_code) >> 8) & 0xff;
106 bpf_get_current_comm(&e->comm, sizeof(e->comm));
107
108 /* send data to user-space for post-processing */
109 bpf_ringbuf_submit(e, 0);
110 return 0;
111}