| // SPDX-License-Identifier: GPL-2.0 |
| /* Copyright (c) 2021 Facebook */ |
| #include "vmlinux.h" |
| #include <bpf/bpf_helpers.h> |
| |
| char _license[] SEC("license") = "GPL"; |
| |
| struct callback_ctx { |
| int dummy; |
| }; |
| |
| static long write_task(struct task_struct *task, struct vm_area_struct *vma, |
| struct callback_ctx *data) |
| { |
| /* writing to task, which is illegal */ |
| task->mm = NULL; |
| |
| return 0; |
| } |
| |
| SEC("raw_tp/sys_enter") |
| int handle_getpid(void) |
| { |
| struct task_struct *task = bpf_get_current_task_btf(); |
| struct callback_ctx data = {}; |
| |
| bpf_find_vma(task, 0, write_task, &data, 0); |
| return 0; |
| } |