[people/ms/linux.git] / fs / init.c

// 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/file.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 = path_permission(&path, 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 = path_permission(&path, 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_chown(const char *filename, uid_t user, gid_t group, int flags)
{
	int lookup_flags = (flags & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW;
	struct path path;
	int error;

	error = kern_path(filename, lookup_flags, &path);
	if (error)
		return error;
	error = mnt_want_write(path.mnt);
	if (!error) {
		error = chown_common(&path, user, group);
		mnt_drop_write(path.mnt);
	}
	path_put(&path);
	return error;
}

int __init init_chmod(const char *filename, umode_t mode)
{
	struct path path;
	int error;

	error = kern_path(filename, LOOKUP_FOLLOW, &path);
	if (error)
		return error;
	error = chmod_common(&path, mode);
	path_put(&path);
	return error;
}

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

	error = kern_path(filename, LOOKUP_FOLLOW, &path);
	if (error)
		return error;
	error = path_permission(&path, MAY_ACCESS);
	path_put(&path);
	return error;
}

int __init init_stat(const char *filename, struct kstat *stat, int flags)
{
	int lookup_flags = (flags & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW;
	struct path path;
	int error;

	error = kern_path(filename, lookup_flags, &path);
	if (error)
		return error;
	error = vfs_getattr(&path, stat, STATX_BASIC_STATS,
			    flags | AT_NO_AUTOMOUNT);
	path_put(&path);
	return error;
}

int __init init_mknod(const char *filename, umode_t mode, unsigned int dev)
{
	struct dentry *dentry;
	struct path path;
	int error;

	if (S_ISFIFO(mode) || S_ISSOCK(mode))
		dev = 0;
	else if (!(S_ISBLK(mode) || S_ISCHR(mode)))
		return -EINVAL;

	dentry = kern_path_create(AT_FDCWD, filename, &path, 0);
	if (IS_ERR(dentry))
		return PTR_ERR(dentry);

	if (!IS_POSIXACL(path.dentry->d_inode))
		mode &= ~current_umask();
	error = security_path_mknod(&path, dentry, mode, dev);
	if (!error)
		error = vfs_mknod(mnt_user_ns(path.mnt), path.dentry->d_inode,
				  dentry, mode, new_decode_dev(dev));
	done_path_create(&path, dentry);
	return error;
}

int __init init_link(const char *oldname, const char *newname)
{
	struct dentry *new_dentry;
	struct path old_path, new_path;
	struct user_namespace *mnt_userns;
	int error;

	error = kern_path(oldname, 0, &old_path);
	if (error)
		return error;

	new_dentry = kern_path_create(AT_FDCWD, newname, &new_path, 0);
	error = PTR_ERR(new_dentry);
	if (IS_ERR(new_dentry))
		goto out;

	error = -EXDEV;
	if (old_path.mnt != new_path.mnt)
		goto out_dput;
	mnt_userns = mnt_user_ns(new_path.mnt);
	error = may_linkat(mnt_userns, &old_path);
	if (unlikely(error))
		goto out_dput;
	error = security_path_link(old_path.dentry, &new_path, new_dentry);
	if (error)
		goto out_dput;
	error = vfs_link(old_path.dentry, mnt_userns, new_path.dentry->d_inode,
			 new_dentry, NULL);
out_dput:
	done_path_create(&new_path, new_dentry);
out:
	path_put(&old_path);
	return error;
}

int __init init_symlink(const char *oldname, const char *newname)
{
	struct dentry *dentry;
	struct path path;
	int error;

	dentry = kern_path_create(AT_FDCWD, newname, &path, 0);
	if (IS_ERR(dentry))
		return PTR_ERR(dentry);
	error = security_path_symlink(&path, dentry, oldname);
	if (!error)
		error = vfs_symlink(mnt_user_ns(path.mnt), path.dentry->d_inode,
				    dentry, oldname);
	done_path_create(&path, dentry);
	return error;
}

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

int __init init_mkdir(const char *pathname, umode_t mode)
{
	struct dentry *dentry;
	struct path path;
	int error;

	dentry = kern_path_create(AT_FDCWD, pathname, &path, LOOKUP_DIRECTORY);
	if (IS_ERR(dentry))
		return PTR_ERR(dentry);
	if (!IS_POSIXACL(path.dentry->d_inode))
		mode &= ~current_umask();
	error = security_path_mkdir(&path, dentry, mode);
	if (!error)
		error = vfs_mkdir(mnt_user_ns(path.mnt), path.dentry->d_inode,
				  dentry, mode);
	done_path_create(&path, dentry);
	return error;
}

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

int __init init_utimes(char *filename, struct timespec64 *ts)
{
	struct path path;
	int error;

	error = kern_path(filename, 0, &path);
	if (error)
		return error;
	error = vfs_utimes(&path, ts);
	path_put(&path);
	return error;
}

int __init init_dup(struct file *file)
{
	int fd;

	fd = get_unused_fd_flags(0);
	if (fd < 0)
		return fd;
	fd_install(fd, get_file(file));
	return 0;
}
Commit	Line	Data
c60166f0 CH	1	// SPDX-License-Identifier: GPL-2.0
	2	/*
	3	* Routines that mimic syscalls, but don't use the user address space or file
	4	* descriptors. Only for init/ and related early init code.
	5	*/
	6	#include <linux/init.h>
	7	#include <linux/mount.h>
	8	#include <linux/namei.h>
	9	#include <linux/fs.h>
db63f1e3	10	#include <linux/fs_struct.h>
f0735310	11	#include <linux/file.h>
c60166f0	12	#include <linux/init_syscalls.h>
4b7ca501	13	#include <linux/security.h>
c60166f0 CH	14	#include "internal.h"
	15
	16	int __init init_mount(const char dev_name, const char dir_name,
	17	const char type_page, unsigned long flags, void data_page)
	18	{
	19	struct path path;
	20	int ret;
	21
	22	ret = kern_path(dir_name, LOOKUP_FOLLOW, &path);
	23	if (ret)
	24	return ret;
	25	ret = path_mount(dev_name, &path, type_page, flags, data_page);
	26	path_put(&path);
	27	return ret;
	28	}
09267def CH	29
	30	int __init init_umount(const char *name, int flags)
	31	{
	32	int lookup_flags = LOOKUP_MOUNTPOINT;
	33	struct path path;
	34	int ret;
	35
	36	if (!(flags & UMOUNT_NOFOLLOW))
	37	lookup_flags \|= LOOKUP_FOLLOW;
	38	ret = kern_path(name, lookup_flags, &path);
	39	if (ret)
	40	return ret;
	41	return path_umount(&path, flags);
	42	}
8fb9f73e	43
db63f1e3 CH	44	int __init init_chdir(const char *filename)
	45	{
	46	struct path path;
	47	int error;
	48
	49	error = kern_path(filename, LOOKUP_FOLLOW \| LOOKUP_DIRECTORY, &path);
	50	if (error)
	51	return error;
02f92b38	52	error = path_permission(&path, MAY_EXEC \| MAY_CHDIR);
db63f1e3 CH	53	if (!error)
	54	set_fs_pwd(current->fs, &path);
	55	path_put(&path);
	56	return error;
	57	}
	58
4b7ca501 CH	59	int __init init_chroot(const char *filename)
	60	{
	61	struct path path;
	62	int error;
	63
	64	error = kern_path(filename, LOOKUP_FOLLOW \| LOOKUP_DIRECTORY, &path);
	65	if (error)
	66	return error;
02f92b38	67	error = path_permission(&path, MAY_EXEC \| MAY_CHDIR);
4b7ca501 CH	68	if (error)
	69	goto dput_and_out;
	70	error = -EPERM;
	71	if (!ns_capable(current_user_ns(), CAP_SYS_CHROOT))
	72	goto dput_and_out;
	73	error = security_path_chroot(&path);
	74	if (error)
	75	goto dput_and_out;
	76	set_fs_root(current->fs, &path);
	77	dput_and_out:
	78	path_put(&path);
	79	return error;
	80	}
	81
b873498f CH	82	int __init init_chown(const char *filename, uid_t user, gid_t group, int flags)
	83	{
	84	int lookup_flags = (flags & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW;
	85	struct path path;
	86	int error;
	87
	88	error = kern_path(filename, lookup_flags, &path);
	89	if (error)
	90	return error;
	91	error = mnt_want_write(path.mnt);
	92	if (!error) {
	93	error = chown_common(&path, user, group);
	94	mnt_drop_write(path.mnt);
	95	}
	96	path_put(&path);
	97	return error;
	98	}
	99
1097742e CH	100	int __init init_chmod(const char *filename, umode_t mode)
	101	{
	102	struct path path;
	103	int error;
	104
	105	error = kern_path(filename, LOOKUP_FOLLOW, &path);
	106	if (error)
	107	return error;
	108	error = chmod_common(&path, mode);
	109	path_put(&path);
	110	return error;
	111	}
	112
eb9d7d39 CH	113	int __init init_eaccess(const char *filename)
	114	{
	115	struct path path;
	116	int error;
	117
	118	error = kern_path(filename, LOOKUP_FOLLOW, &path);
	119	if (error)
	120	return error;
02f92b38	121	error = path_permission(&path, MAY_ACCESS);
eb9d7d39 CH	122	path_put(&path);
	123	return error;
	124	}
	125
716308a5 CH	126	int __init init_stat(const char filename, struct kstat stat, int flags)
	127	{
	128	int lookup_flags = (flags & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW;
	129	struct path path;
	130	int error;
	131
	132	error = kern_path(filename, lookup_flags, &path);
	133	if (error)
	134	return error;
	135	error = vfs_getattr(&path, stat, STATX_BASIC_STATS,
	136	flags \| AT_NO_AUTOMOUNT);
	137	path_put(&path);
	138	return error;
	139	}
	140
5fee64fc CH	141	int __init init_mknod(const char *filename, umode_t mode, unsigned int dev)
	142	{
	143	struct dentry *dentry;
	144	struct path path;
	145	int error;
	146
	147	if (S_ISFIFO(mode) \|\| S_ISSOCK(mode))
	148	dev = 0;
	149	else if (!(S_ISBLK(mode) \|\| S_ISCHR(mode)))
	150	return -EINVAL;
	151
	152	dentry = kern_path_create(AT_FDCWD, filename, &path, 0);
	153	if (IS_ERR(dentry))
	154	return PTR_ERR(dentry);
	155
	156	if (!IS_POSIXACL(path.dentry->d_inode))
	157	mode &= ~current_umask();
	158	error = security_path_mknod(&path, dentry, mode, dev);
	159	if (!error)
b816dd5d CB	160	error = vfs_mknod(mnt_user_ns(path.mnt), path.dentry->d_inode,
b816dd5d CB	161	dentry, mode, new_decode_dev(dev));
5fee64fc CH	162	done_path_create(&path, dentry);
	163	return error;
	164	}
	165
812931d6 CH	166	int __init init_link(const char oldname, const char newname)
	167	{
	168	struct dentry *new_dentry;
	169	struct path old_path, new_path;
b816dd5d	170	struct user_namespace *mnt_userns;
812931d6 CH	171	int error;
	172
	173	error = kern_path(oldname, 0, &old_path);
	174	if (error)
	175	return error;
	176
	177	new_dentry = kern_path_create(AT_FDCWD, newname, &new_path, 0);
	178	error = PTR_ERR(new_dentry);
	179	if (IS_ERR(new_dentry))
	180	goto out;
	181
	182	error = -EXDEV;
	183	if (old_path.mnt != new_path.mnt)
	184	goto out_dput;
b816dd5d CB	185	mnt_userns = mnt_user_ns(new_path.mnt);
b816dd5d CB	186	error = may_linkat(mnt_userns, &old_path);
812931d6 CH	187	if (unlikely(error))
	188	goto out_dput;
	189	error = security_path_link(old_path.dentry, &new_path, new_dentry);
	190	if (error)
	191	goto out_dput;
b816dd5d CB	192	error = vfs_link(old_path.dentry, mnt_userns, new_path.dentry->d_inode,
b816dd5d CB	193	new_dentry, NULL);
812931d6 CH	194	out_dput:
	195	done_path_create(&new_path, new_dentry);
	196	out:
	197	path_put(&old_path);
	198	return error;
	199	}
	200
cd3acb6a CH	201	int __init init_symlink(const char oldname, const char newname)
	202	{
	203	struct dentry *dentry;
	204	struct path path;
	205	int error;
	206
	207	dentry = kern_path_create(AT_FDCWD, newname, &path, 0);
	208	if (IS_ERR(dentry))
	209	return PTR_ERR(dentry);
	210	error = security_path_symlink(&path, dentry, oldname);
	211	if (!error)
b816dd5d CB	212	error = vfs_symlink(mnt_user_ns(path.mnt), path.dentry->d_inode,
b816dd5d CB	213	dentry, oldname);
cd3acb6a CH	214	done_path_create(&path, dentry);
	215	return error;
	216	}
	217
8fb9f73e CH	218	int __init init_unlink(const char *pathname)
	219	{
	220	return do_unlinkat(AT_FDCWD, getname_kernel(pathname));
	221	}
20cce026	222
83ff98c3 CH	223	int __init init_mkdir(const char *pathname, umode_t mode)
	224	{
	225	struct dentry *dentry;
	226	struct path path;
	227	int error;
	228
	229	dentry = kern_path_create(AT_FDCWD, pathname, &path, LOOKUP_DIRECTORY);
	230	if (IS_ERR(dentry))
	231	return PTR_ERR(dentry);
	232	if (!IS_POSIXACL(path.dentry->d_inode))
	233	mode &= ~current_umask();
	234	error = security_path_mkdir(&path, dentry, mode);
	235	if (!error)
b816dd5d CB	236	error = vfs_mkdir(mnt_user_ns(path.mnt), path.dentry->d_inode,
b816dd5d CB	237	dentry, mode);
83ff98c3 CH	238	done_path_create(&path, dentry);
	239	return error;
	240	}
	241
20cce026 CH	242	int __init init_rmdir(const char *pathname)
	243	{
	244	return do_rmdir(AT_FDCWD, getname_kernel(pathname));
	245	}
235e5793 CH	246
	247	int __init init_utimes(char filename, struct timespec64 ts)
	248	{
	249	struct path path;
	250	int error;
	251
	252	error = kern_path(filename, 0, &path);
	253	if (error)
	254	return error;
	255	error = vfs_utimes(&path, ts);
	256	path_put(&path);
	257	return error;
	258	}
f0735310 CH	259
	260	int __init init_dup(struct file *file)
	261	{
	262	int fd;
	263
	264	fd = get_unused_fd_flags(0);
	265	if (fd < 0)
	266	return fd;
	267	fd_install(fd, get_file(file));
	268	return 0;
	269	}