blob: 687081a724b33325316e765b0a027508b15a0e1c (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
|
// SPDX-License-Identifier: GPL-2.0
#include <vmlinux.h>
#include <bpf/bpf_tracing.h>
#include <bpf/bpf_helpers.h>
struct map_value {
struct task_struct __kptr *ptr;
};
struct {
__uint(type, BPF_MAP_TYPE_LRU_HASH);
__uint(max_entries, 1);
__type(key, int);
__type(value, struct map_value);
} lru_map SEC(".maps");
int pid = 0;
int result = 1;
SEC("fentry/bpf_ktime_get_ns")
int printk(void *ctx)
{
struct map_value v = {};
if (pid == bpf_get_current_task_btf()->pid)
bpf_map_update_elem(&lru_map, &(int){0}, &v, 0);
return 0;
}
SEC("fentry/do_nanosleep")
int nanosleep(void *ctx)
{
struct map_value val = {}, *v;
struct task_struct *current;
bpf_map_update_elem(&lru_map, &(int){0}, &val, 0);
v = bpf_map_lookup_elem(&lru_map, &(int){0});
if (!v)
return 0;
bpf_map_delete_elem(&lru_map, &(int){0});
current = bpf_get_current_task_btf();
v->ptr = current;
pid = current->pid;
bpf_ktime_get_ns();
result = !v->ptr;
return 0;
}
char _license[] SEC("license") = "GPL";
|
