xref: /linux/samples/bpf/syscall_tp_kern.c (revision 4b132aacb0768ac1e652cf517097ea6f237214b9)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2017 Facebook
3  */
4 #include <uapi/linux/bpf.h>
5 #include <bpf/bpf_helpers.h>
6 
7 #if !defined(__aarch64__)
8 struct syscalls_enter_open_args {
9 	unsigned long long unused;
10 	long syscall_nr;
11 	long filename_ptr;
12 	long flags;
13 	long mode;
14 };
15 #endif
16 
17 struct syscalls_exit_open_args {
18 	unsigned long long unused;
19 	long syscall_nr;
20 	long ret;
21 };
22 
23 struct syscalls_enter_open_at_args {
24 	unsigned long long unused;
25 	long syscall_nr;
26 	long long dfd;
27 	long filename_ptr;
28 	long flags;
29 	long mode;
30 };
31 
32 struct {
33 	__uint(type, BPF_MAP_TYPE_ARRAY);
34 	__type(key, u32);
35 	__type(value, u32);
36 	__uint(max_entries, 1);
37 } enter_open_map SEC(".maps");
38 
39 struct {
40 	__uint(type, BPF_MAP_TYPE_ARRAY);
41 	__type(key, u32);
42 	__type(value, u32);
43 	__uint(max_entries, 1);
44 } exit_open_map SEC(".maps");
45 
46 static __always_inline void count(void *map)
47 {
48 	u32 key = 0;
49 	u32 *value, init_val = 1;
50 
51 	value = bpf_map_lookup_elem(map, &key);
52 	if (value)
53 		*value += 1;
54 	else
55 		bpf_map_update_elem(map, &key, &init_val, BPF_NOEXIST);
56 }
57 
58 #if !defined(__aarch64__)
59 SEC("tracepoint/syscalls/sys_enter_open")
60 int trace_enter_open(struct syscalls_enter_open_args *ctx)
61 {
62 	count(&enter_open_map);
63 	return 0;
64 }
65 #endif
66 
67 SEC("tracepoint/syscalls/sys_enter_openat")
68 int trace_enter_open_at(struct syscalls_enter_open_at_args *ctx)
69 {
70 	count(&enter_open_map);
71 	return 0;
72 }
73 
74 SEC("tracepoint/syscalls/sys_enter_openat2")
75 int trace_enter_open_at2(struct syscalls_enter_open_at_args *ctx)
76 {
77 	count(&enter_open_map);
78 	return 0;
79 }
80 
81 #if !defined(__aarch64__)
82 SEC("tracepoint/syscalls/sys_exit_open")
83 int trace_enter_exit(struct syscalls_exit_open_args *ctx)
84 {
85 	count(&exit_open_map);
86 	return 0;
87 }
88 #endif
89 
90 SEC("tracepoint/syscalls/sys_exit_openat")
91 int trace_enter_exit_at(struct syscalls_exit_open_args *ctx)
92 {
93 	count(&exit_open_map);
94 	return 0;
95 }
96 
97 SEC("tracepoint/syscalls/sys_exit_openat2")
98 int trace_enter_exit_at2(struct syscalls_exit_open_args *ctx)
99 {
100 	count(&exit_open_map);
101 	return 0;
102 }
103