Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) #include <linux/mount.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3) #include <linux/pseudo_fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4) #include <linux/file.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5) #include <linux/fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6) #include <linux/proc_fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7) #include <linux/proc_ns.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) #include <linux/magic.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) #include <linux/ktime.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) #include <linux/seq_file.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) #include <linux/user_namespace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) #include <linux/nsfs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include "internal.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) static struct vfsmount *nsfs_mnt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) static long ns_ioctl(struct file *filp, unsigned int ioctl,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) 			unsigned long arg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) static const struct file_operations ns_file_operations = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) 	.llseek		= no_llseek,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) 	.unlocked_ioctl = ns_ioctl,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) static char *ns_dname(struct dentry *dentry, char *buffer, int buflen)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) 	struct inode *inode = d_inode(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) 	const struct proc_ns_operations *ns_ops = dentry->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 	return dynamic_dname(dentry, buffer, buflen, "%s:[%lu]",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 		ns_ops->name, inode->i_ino);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) static void ns_prune_dentry(struct dentry *dentry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 	struct inode *inode = d_inode(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 	if (inode) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 		struct ns_common *ns = inode->i_private;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 		atomic_long_set(&ns->stashed, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) const struct dentry_operations ns_dentry_operations =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 	.d_prune	= ns_prune_dentry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 	.d_delete	= always_delete_dentry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 	.d_dname	= ns_dname,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) static void nsfs_evict(struct inode *inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 	struct ns_common *ns = inode->i_private;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 	clear_inode(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 	ns->ops->put(ns);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) static int __ns_get_path(struct path *path, struct ns_common *ns)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 	struct vfsmount *mnt = nsfs_mnt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 	struct dentry *dentry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 	struct inode *inode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 	unsigned long d;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 	d = atomic_long_read(&ns->stashed);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 	if (!d)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 		goto slow;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 	dentry = (struct dentry *)d;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 	if (!lockref_get_not_dead(&dentry->d_lockref))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 		goto slow;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 	rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 	ns->ops->put(ns);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) got_it:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 	path->mnt = mntget(mnt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 	path->dentry = dentry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) slow:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 	rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 	inode = new_inode_pseudo(mnt->mnt_sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 	if (!inode) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 		ns->ops->put(ns);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 		return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 	inode->i_ino = ns->inum;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 	inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 	inode->i_flags |= S_IMMUTABLE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 	inode->i_mode = S_IFREG | S_IRUGO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 	inode->i_fop = &ns_file_operations;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 	inode->i_private = ns;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 	dentry = d_alloc_anon(mnt->mnt_sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 	if (!dentry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 		iput(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 		return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 	d_instantiate(dentry, inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 	dentry->d_fsdata = (void *)ns->ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 	d = atomic_long_cmpxchg(&ns->stashed, 0, (unsigned long)dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 	if (d) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 		d_delete(dentry);	/* make sure ->d_prune() does nothing */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 		dput(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 		cpu_relax();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 		return -EAGAIN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 	goto got_it;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) int ns_get_path_cb(struct path *path, ns_get_path_helper_t *ns_get_cb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 		     void *private_data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 	do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 		struct ns_common *ns = ns_get_cb(private_data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 		if (!ns)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 			return -ENOENT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 		ret = __ns_get_path(path, ns);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 	} while (ret == -EAGAIN);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) struct ns_get_path_task_args {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 	const struct proc_ns_operations *ns_ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 	struct task_struct *task;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) static struct ns_common *ns_get_path_task(void *private_data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 	struct ns_get_path_task_args *args = private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 	return args->ns_ops->get(args->task);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) int ns_get_path(struct path *path, struct task_struct *task,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 		  const struct proc_ns_operations *ns_ops)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 	struct ns_get_path_task_args args = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 		.ns_ops	= ns_ops,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 		.task	= task,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 	};
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 	return ns_get_path_cb(path, ns_get_path_task, &args);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) int open_related_ns(struct ns_common *ns,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 		   struct ns_common *(*get_ns)(struct ns_common *ns))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 	struct path path = {};
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 	struct file *f;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 	int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 	int fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 	fd = get_unused_fd_flags(O_CLOEXEC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 	if (fd < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 		return fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 	do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 		struct ns_common *relative;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 		relative = get_ns(ns);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 		if (IS_ERR(relative)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 			put_unused_fd(fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 			return PTR_ERR(relative);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 		err = __ns_get_path(&path, relative);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 	} while (err == -EAGAIN);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 	if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 		put_unused_fd(fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 		return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 	f = dentry_open(&path, O_RDONLY, current_cred());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 	path_put(&path);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 	if (IS_ERR(f)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 		put_unused_fd(fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 		fd = PTR_ERR(f);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 	} else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 		fd_install(fd, f);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 	return fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) EXPORT_SYMBOL_GPL(open_related_ns);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) static long ns_ioctl(struct file *filp, unsigned int ioctl,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 			unsigned long arg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 	struct user_namespace *user_ns;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 	struct ns_common *ns = get_proc_ns(file_inode(filp));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 	uid_t __user *argp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 	uid_t uid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 	switch (ioctl) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 	case NS_GET_USERNS:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 		return open_related_ns(ns, ns_get_owner);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 	case NS_GET_PARENT:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 		if (!ns->ops->get_parent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 			return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 		return open_related_ns(ns, ns->ops->get_parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 	case NS_GET_NSTYPE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 		return ns->ops->type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 	case NS_GET_OWNER_UID:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 		if (ns->ops->type != CLONE_NEWUSER)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 			return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 		user_ns = container_of(ns, struct user_namespace, ns);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 		argp = (uid_t __user *) arg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 		uid = from_kuid_munged(current_user_ns(), user_ns->owner);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 		return put_user(uid, argp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 	default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 		return -ENOTTY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) int ns_get_name(char *buf, size_t size, struct task_struct *task,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 			const struct proc_ns_operations *ns_ops)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 	struct ns_common *ns;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 	int res = -ENOENT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 	const char *name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 	ns = ns_ops->get(task);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 	if (ns) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 		name = ns_ops->real_ns_name ? : ns_ops->name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 		res = snprintf(buf, size, "%s:[%u]", name, ns->inum);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 		ns_ops->put(ns);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 	return res;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) bool proc_ns_file(const struct file *file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) 	return file->f_op == &ns_file_operations;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) struct file *proc_ns_fget(int fd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 	struct file *file;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 	file = fget(fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 	if (!file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 		return ERR_PTR(-EBADF);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 	if (file->f_op != &ns_file_operations)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 		goto out_invalid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 	return file;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) out_invalid:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 	fput(file);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) 	return ERR_PTR(-EINVAL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256)  * ns_match() - Returns true if current namespace matches dev/ino provided.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257)  * @ns_common: current ns
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258)  * @dev: dev_t from nsfs that will be matched against current nsfs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259)  * @ino: ino_t from nsfs that will be matched against current nsfs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261)  * Return: true if dev and ino matches the current nsfs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) bool ns_match(const struct ns_common *ns, dev_t dev, ino_t ino)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) 	return (ns->inum == ino) && (nsfs_mnt->mnt_sb->s_dev == dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) static int nsfs_show_path(struct seq_file *seq, struct dentry *dentry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) 	struct inode *inode = d_inode(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 	const struct proc_ns_operations *ns_ops = dentry->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) 	seq_printf(seq, "%s:[%lu]", ns_ops->name, inode->i_ino);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) static const struct super_operations nsfs_ops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) 	.statfs = simple_statfs,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 	.evict_inode = nsfs_evict,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) 	.show_path = nsfs_show_path,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) static int nsfs_init_fs_context(struct fs_context *fc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) 	struct pseudo_fs_context *ctx = init_pseudo(fc, NSFS_MAGIC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) 	if (!ctx)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) 		return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) 	ctx->ops = &nsfs_ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) 	ctx->dops = &ns_dentry_operations;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) static struct file_system_type nsfs = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) 	.name = "nsfs",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) 	.init_fs_context = nsfs_init_fs_context,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) 	.kill_sb = kill_anon_super,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) void __init nsfs_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) 	nsfs_mnt = kern_mount(&nsfs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) 	if (IS_ERR(nsfs_mnt))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) 		panic("can't set nsfs up\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) 	nsfs_mnt->mnt_sb->s_flags &= ~SB_NOUSER;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) }