1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* Copyright (c) 2021 Facebook */ |
3 | #include "vmlinux.h" |
4 | #include <bpf/bpf_helpers.h> |
5 | |
6 | char _license[] SEC("license" ) = "GPL" ; |
7 | |
8 | struct callback_ctx { |
9 | int dummy; |
10 | }; |
11 | |
12 | static long write_task(struct task_struct *task, struct vm_area_struct *vma, |
13 | struct callback_ctx *data) |
14 | { |
15 | /* writing to task, which is illegal */ |
16 | task->mm = NULL; |
17 | |
18 | return 0; |
19 | } |
20 | |
21 | SEC("raw_tp/sys_enter" ) |
22 | int handle_getpid(void) |
23 | { |
24 | struct task_struct *task = bpf_get_current_task_btf(); |
25 | struct callback_ctx data = {}; |
26 | |
27 | bpf_find_vma(task, 0, write_task, &data, 0); |
28 | return 0; |
29 | } |
30 | |