1 // SPDX-License-Identifier: GPL-2.0
2
3 #include "vmlinux.h"
4 #include <bpf/bpf_helpers.h>
5 #include <bpf/bpf_tracing.h>
6
7 char _license[] SEC("license") = "GPL";
8
9 #ifndef EBUSY
10 #define EBUSY 16
11 #endif
12
13 extern bool CONFIG_PREEMPT __kconfig __weak;
14 int nr_get_errs = 0;
15 int nr_del_errs = 0;
16
17 struct {
18 __uint(type, BPF_MAP_TYPE_TASK_STORAGE);
19 __uint(map_flags, BPF_F_NO_PREALLOC);
20 __type(key, int);
21 __type(value, int);
22 } task_storage SEC(".maps");
23
24 SEC("lsm.s/socket_post_create")
BPF_PROG(socket_post_create,struct socket * sock,int family,int type,int protocol,int kern)25 int BPF_PROG(socket_post_create, struct socket *sock, int family, int type,
26 int protocol, int kern)
27 {
28 struct task_struct *task;
29 int ret, zero = 0;
30 int *value;
31
32 if (!CONFIG_PREEMPT)
33 return 0;
34
35 task = bpf_get_current_task_btf();
36 value = bpf_task_storage_get(&task_storage, task, &zero,
37 BPF_LOCAL_STORAGE_GET_F_CREATE);
38 if (!value)
39 __sync_fetch_and_add(&nr_get_errs, 1);
40
41 ret = bpf_task_storage_delete(&task_storage,
42 bpf_get_current_task_btf());
43 if (ret == -EBUSY)
44 __sync_fetch_and_add(&nr_del_errs, 1);
45
46 return 0;
47 }
48