tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (C) 2024. Huawei Technologies Co., Ltd */
3#include "vmlinux.h"
4#include <linux/types.h>
5#include <bpf/bpf_helpers.h>
6
7#include "bpf_misc.h"
8
9int target_pid = 0;
10void *user_ptr = 0;
11int read_ret[9];
12
13char _license[] SEC("license") = "GPL";
14
15/*
16 * This is the only kfunc, the others are helpers
17 */
18int bpf_copy_from_user_str(void *dst, u32, const void *, u64) __weak __ksym;
19
20SEC("fentry/" SYS_PREFIX "sys_nanosleep")
21int do_probe_read(void *ctx)
22{
23 char buf[8];
24
25 if ((bpf_get_current_pid_tgid() >> 32) != target_pid)
26 return 0;
27
28 read_ret[0] = bpf_probe_read_kernel(buf, sizeof(buf), user_ptr);
29 read_ret[1] = bpf_probe_read_kernel_str(buf, sizeof(buf), user_ptr);
30 read_ret[2] = bpf_probe_read(buf, sizeof(buf), user_ptr);
31 read_ret[3] = bpf_probe_read_str(buf, sizeof(buf), user_ptr);
32 read_ret[4] = bpf_probe_read_user(buf, sizeof(buf), user_ptr);
33 read_ret[5] = bpf_probe_read_user_str(buf, sizeof(buf), user_ptr);
34
35 return 0;
36}
37
38SEC("fentry.s/" SYS_PREFIX "sys_nanosleep")
39int do_copy_from_user(void *ctx)
40{
41 char buf[8];
42
43 if ((bpf_get_current_pid_tgid() >> 32) != target_pid)
44 return 0;
45
46 read_ret[6] = bpf_copy_from_user(buf, sizeof(buf), user_ptr);
47 read_ret[7] = bpf_copy_from_user_task(buf, sizeof(buf), user_ptr,
48 bpf_get_current_task_btf(), 0);
49 read_ret[8] = bpf_copy_from_user_str((char *)buf, sizeof(buf), user_ptr, 0);
50
51 return 0;
52}