1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2024 Jose Fernandez
3
4 #include "vmlinux.h"
5 #include <bpf/bpf_helpers.h>
6 #include <bpf/bpf_tracing.h>
7
8 struct {
9 __uint(type, BPF_MAP_TYPE_USER_RINGBUF);
10 __uint(max_entries, 4096 /* one page */);
11 } user_ringbuf SEC(".maps");
12
13 struct {
14 __uint(type, BPF_MAP_TYPE_HASH);
15 __type(key, u32);
16 __type(value, u32);
17 __uint(max_entries, 100);
18 } samples SEC(".maps");
19
20 struct my_struct_t {
21 u32 key;
22 u32 value;
23 };
24
user_ringbuf_callback(struct bpf_dynptr * dynptr,void * context)25 static long user_ringbuf_callback(struct bpf_dynptr *dynptr, void *context)
26 {
27 const struct my_struct_t *data;
28
29 data = bpf_dynptr_data(dynptr, 0, sizeof(*data));
30 if (!data)
31 return 0;
32
33 bpf_map_update_elem(&samples, &data->key, &data->value, BPF_ANY);
34
35 return 0;
36 }
37
38 SEC("tp/syscalls/sys_enter_getpid")
handle__sys_enter_getpid(void * ctx)39 int handle__sys_enter_getpid(void *ctx)
40 {
41 bpf_user_ringbuf_drain(&user_ringbuf, user_ringbuf_callback, NULL, 0);
42
43 return 0;
44 }
45
46 char LICENSE[] SEC("license") = "GPL";
47