xref: /linux/tools/testing/selftests/bpf/progs/read_vsyscall.c (revision 4f9786035f9e519db41375818e1d0b5f20da2f10)
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 
9 int target_pid = 0;
10 void *user_ptr = 0;
11 int read_ret[10];
12 
13 char _license[] SEC("license") = "GPL";
14 
15 /*
16  * These are the kfuncs, the others are helpers
17  */
18 int bpf_copy_from_user_str(void *dst, u32, const void *, u64) __weak __ksym;
19 int bpf_copy_from_user_task_str(void *dst, u32, const void *,
20 				struct task_struct *, u64) __weak __ksym;
21 
22 SEC("fentry/" SYS_PREFIX "sys_nanosleep")
23 int do_probe_read(void *ctx)
24 {
25 	char buf[8];
26 
27 	if ((bpf_get_current_pid_tgid() >> 32) != target_pid)
28 		return 0;
29 
30 	read_ret[0] = bpf_probe_read_kernel(buf, sizeof(buf), user_ptr);
31 	read_ret[1] = bpf_probe_read_kernel_str(buf, sizeof(buf), user_ptr);
32 	read_ret[2] = bpf_probe_read(buf, sizeof(buf), user_ptr);
33 	read_ret[3] = bpf_probe_read_str(buf, sizeof(buf), user_ptr);
34 	read_ret[4] = bpf_probe_read_user(buf, sizeof(buf), user_ptr);
35 	read_ret[5] = bpf_probe_read_user_str(buf, sizeof(buf), user_ptr);
36 
37 	return 0;
38 }
39 
40 SEC("fentry.s/" SYS_PREFIX "sys_nanosleep")
41 int do_copy_from_user(void *ctx)
42 {
43 	char buf[8];
44 
45 	if ((bpf_get_current_pid_tgid() >> 32) != target_pid)
46 		return 0;
47 
48 	read_ret[6] = bpf_copy_from_user(buf, sizeof(buf), user_ptr);
49 	read_ret[7] = bpf_copy_from_user_task(buf, sizeof(buf), user_ptr,
50 					      bpf_get_current_task_btf(), 0);
51 	read_ret[8] = bpf_copy_from_user_str((char *)buf, sizeof(buf), user_ptr, 0);
52 	read_ret[9] = bpf_copy_from_user_task_str((char *)buf,
53 						  sizeof(buf),
54 						  user_ptr,
55 						  bpf_get_current_task_btf(),
56 						  0);
57 
58 	return 0;
59 }
60