aboutsummaryrefslogtreecommitdiffstats
path: root/fs/init.c
blob: 2c78f24814dde4ea0c18aa501f1076f476547590 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
// SPDX-License-Identifier: GPL-2.0
/*
 * Routines that mimic syscalls, but don't use the user address space or file
 * descriptors.  Only for init/ and related early init code.
 */
#include <linux/init.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/fs.h>
#include <linux/fs_struct.h>
#include <linux/init_syscalls.h>
#include <linux/security.h>
#include "internal.h"

int __init init_mount(const char *dev_name, const char *dir_name,
		const char *type_page, unsigned long flags, void *data_page)
{
	struct path path;
	int ret;

	ret = kern_path(dir_name, LOOKUP_FOLLOW, &path);
	if (ret)
		return ret;
	ret = path_mount(dev_name, &path, type_page, flags, data_page);
	path_put(&path);
	return ret;
}

int __init init_umount(const char *name, int flags)
{
	int lookup_flags = LOOKUP_MOUNTPOINT;
	struct path path;
	int ret;

	if (!(flags & UMOUNT_NOFOLLOW))
		lookup_flags |= LOOKUP_FOLLOW;
	ret = kern_path(name, lookup_flags, &path);
	if (ret)
		return ret;
	return path_umount(&path, flags);
}

int __init init_chdir(const char *filename)
{
	struct path path;
	int error;

	error = kern_path(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
	if (error)
		return error;
	error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR);
	if (!error)
		set_fs_pwd(current->fs, &path);
	path_put(&path);
	return error;
}

int __init init_chroot(const char *filename)
{
	struct path path;
	int error;

	error = kern_path(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
	if (error)
		return error;
	error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR);
	if (error)
		goto dput_and_out;
	error = -EPERM;
	if (!ns_capable(current_user_ns(), CAP_SYS_CHROOT))
		goto dput_and_out;
	error = security_path_chroot(&path);
	if (error)
		goto dput_and_out;
	set_fs_root(current->fs, &path);
dput_and_out:
	path_put(&path);
	return error;
}

int __init init_unlink(const char *pathname)
{
	return do_unlinkat(AT_FDCWD, getname_kernel(pathname));
}

int __init init_rmdir(const char *pathname)
{
	return do_rmdir(AT_FDCWD, getname_kernel(pathname));
}