Release 4.17 fs/proc/root.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  linux/fs/proc/root.c
 *
 *  Copyright (C) 1991, 1992 Linus Torvalds
 *
 *  proc root directory handling functions
 */

#include <linux/uaccess.h>

#include <linux/errno.h>
#include <linux/time.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/sched/stat.h>
#include <linux/module.h>
#include <linux/bitops.h>
#include <linux/user_namespace.h>
#include <linux/mount.h>
#include <linux/pid_namespace.h>
#include <linux/parser.h>
#include <linux/cred.h>

#include "internal.h"


enum {
	


Opt_gid, Opt_hidepid, Opt_err,
};


static const match_table_t tokens = {
	{Opt_hidepid, "hidepid=%u"},
	{Opt_gid, "gid=%u"},
	{Opt_err, NULL},
};



int proc_parse_options(char *options, struct pid_namespace *pid)
{
	char *p;
	substring_t args[MAX_OPT_ARGS];
	int option;

	if (!options)
		return 1;

	while ((p = strsep(&options, ",")) != NULL) {
		int token;
		if (!*p)
			continue;

		args[0].to = args[0].from = NULL;
		token = match_token(p, tokens, args);
		switch (token) {
		case Opt_gid:
			if (match_int(&args[0], &option))
				return 0;
			pid->pid_gid = make_kgid(current_user_ns(), option);
			break;
		case Opt_hidepid:
			if (match_int(&args[0], &option))
				return 0;
			if (option < HIDEPID_OFF ||
			    option > HIDEPID_INVISIBLE) {
				pr_err("proc: hidepid value must be between 0 and 2.\n");
				return 0;
			}
			pid->hide_pid = option;
			break;
		default:
			pr_err("proc: unrecognized mount option \"%s\" "
			       "or missing value\n", p);
			return 0;
		}
	}

	return 1;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Vasiliy Kulikov
182
95.29%
2
40.00%
Eric W. Biedermann
6
3.14%
1
20.00%
Lafcadio Wluiki
2
1.05%
1
20.00%
Sachin Kamat
1
0.52%
1
20.00%
Total
191
100.00%
5
100.00%



int proc_remount(struct super_block *sb, int *flags, char *data)
{
	struct pid_namespace *pid = sb->s_fs_info;

	sync_filesystem(sb);
	return !proc_parse_options(data, pid);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Vasiliy Kulikov
36
87.80%
1
50.00%
Theodore Y. Ts'o
5
12.20%
1
50.00%
Total
41
100.00%
2
100.00%



static struct dentry *proc_mount(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *data)
{
	struct pid_namespace *ns;

	if (flags & SB_KERNMOUNT) {
		ns = data;
		data = NULL;
	} else {
		ns = task_active_pid_ns(current);
	}

	return mount_ns(fs_type, flags, data, ns, ns->user_ns, proc_fill_super);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Al Viro
26
35.14%
2
16.67%
Pavel Emelyanov
18
24.32%
1
8.33%
Eric W. Biedermann
12
16.22%
3
25.00%
Vasiliy Kulikov
10
13.51%
2
16.67%
Linus Torvalds
5
6.76%
2
16.67%
David Howells
2
2.70%
1
8.33%
Andries E. Brouwer
1
1.35%
1
8.33%
Total
74
100.00%
12
100.00%



static void proc_kill_sb(struct super_block *sb)
{
	struct pid_namespace *ns;

	ns = (struct pid_namespace *)sb->s_fs_info;
	if (ns->proc_self)
		dput(ns->proc_self);
	if (ns->proc_thread_self)
		dput(ns->proc_thread_self);
	kill_anon_super(sb);
	put_pid_ns(ns);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Pavel Emelyanov
37
58.73%
1
33.33%
Eric W. Biedermann
13
20.63%
1
33.33%
Al Viro
13
20.63%
1
33.33%
Total
63
100.00%
3
100.00%


static struct file_system_type proc_fs_type = {
	.name		= "proc",
	.mount		= proc_mount,
	.kill_sb	= proc_kill_sb,
	.fs_flags	= FS_USERNS_MOUNT,
};



void __init proc_root_init(void)
{
	proc_init_kmemcache();
	set_proc_pid_nlink();
	proc_self_init();
	proc_thread_self_init();
	proc_symlink("mounts", NULL, "self/mounts");

	proc_net_init();
	proc_mkdir("fs", NULL);
	proc_mkdir("driver", NULL);
	proc_create_mount_point("fs/nfsd"); /* somewhere for the nfsd filesystem to be mounted */
#if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE)
	/* just give it a mountpoint */
	proc_create_mount_point("openprom");
#endif
	proc_tty_init();
	proc_mkdir("bus", NULL);
	proc_sys_init();

	register_filesystem(&proc_fs_type);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds (pre-git)
48
53.33%
7
31.82%
Alexey Dobriyan
18
20.00%
5
22.73%
Eric W. Biedermann
13
14.44%
5
22.73%
Neil Brown
5
5.56%
1
4.55%
Mika Kukkonen
3
3.33%
1
4.55%
Al Viro
1
1.11%
1
4.55%
Linus Torvalds
1
1.11%
1
4.55%
Harald Welte
1
1.11%
1
4.55%
Total
90
100.00%
22
100.00%



static int proc_root_getattr(const struct path *path, struct kstat *stat,
			     u32 request_mask, unsigned int query_flags)
{
	generic_fillattr(d_inode(path->dentry), stat);
	stat->nlink = proc_root.nlink + nr_processes();
	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Al Viro
35
70.00%
1
33.33%
David Howells
15
30.00%
2
66.67%
Total
50
100.00%
3
100.00%



static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, unsigned int flags)
{
	if (!proc_pid_lookup(dir, dentry, flags))
		return NULL;
	
	return proc_lookup(dir, dentry, flags);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds (pre-git)
37
78.72%
6
66.67%
Al Viro
5
10.64%
1
11.11%
Trond Myklebust
3
6.38%
1
11.11%
Alexey Dobriyan
2
4.26%
1
11.11%
Total
47
100.00%
9
100.00%



static int proc_root_readdir(struct file *file, struct dir_context *ctx)
{
	if (ctx->pos < FIRST_PROCESS_ENTRY) {
		int error = proc_readdir(file, ctx);
		if (unlikely(error <= 0))
			return error;
		ctx->pos = FIRST_PROCESS_ENTRY;
	}

	return proc_pid_readdir(file, ctx);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds (pre-git)
32
51.61%
7
77.78%
Richard Genoud
16
25.81%
1
11.11%
Al Viro
14
22.58%
1
11.11%
Total
62
100.00%
9
100.00%

/*
 * The root /proc directory is special, as it has the
 * <pid> directories. Thus we don't use the generic
 * directory handling functions for that..
 */

static const struct file_operations proc_root_operations = {
	.read		 = generic_read_dir,
	.iterate_shared	 = proc_root_readdir,
	.llseek		= generic_file_llseek,
};

/*
 * proc root can do almost nothing..
 */

static const struct inode_operations proc_root_inode_operations = {
	.lookup		= proc_root_lookup,
	.getattr	= proc_root_getattr,
};

/*
 * This is the root "inode" in the /proc tree..
 */

struct proc_dir_entry proc_root = {
	.low_ino	= PROC_ROOT_INO, 
	.namelen	= 5, 
	.mode		= S_IFDIR | S_IRUGO | S_IXUGO, 
	.nlink		= 2, 
	.refcnt		= REFCOUNT_INIT(1),
	.proc_iops	= &proc_root_inode_operations, 
	.proc_fops	= &proc_root_operations,
	.parent		= &proc_root,
	.subdir		= RB_ROOT,
	.name		= proc_root.inline_name,
	.inline_name	= "/proc",
};



int pid_ns_prepare_proc(struct pid_namespace *ns)
{
	struct vfsmount *mnt;

	mnt = kern_mount_data(&proc_fs_type, ns);
	if (IS_ERR(mnt))
		return PTR_ERR(mnt);

	ns->proc_mnt = mnt;
	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Pavel Emelyanov
41
87.23%
1
50.00%
Al Viro
6
12.77%
1
50.00%
Total
47
100.00%
2
100.00%



void pid_ns_release_proc(struct pid_namespace *ns)
{
	kern_unmount(ns->proc_mnt);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Pavel Emelyanov
16
94.12%
1
50.00%
Al Viro
1
5.88%
1
50.00%
Total
17
100.00%
2
100.00%

Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Vasiliy Kulikov
265
29.12%
3
3.37%
Linus Torvalds (pre-git)
195
21.43%
21
23.60%
Al Viro
127
13.96%
13
14.61%
Pavel Emelyanov
116
12.75%
2
2.25%
Eric W. Biedermann
55
6.04%
11
12.36%
Alexey Dobriyan
37
4.07%
11
12.36%
Art Haas
26
2.86%
1
1.12%
David Howells
22
2.42%
4
4.49%
Richard Genoud
16
1.76%
1
1.12%
Linus Torvalds
10
1.10%
4
4.49%
Ingo Molnar
6
0.66%
2
2.25%
Theodore Y. Ts'o
5
0.55%
1
1.12%
Neil Brown
5
0.55%
1
1.12%
Arnd Bergmann
4
0.44%
1
1.12%
Nicolas Dichtel
4
0.44%
1
1.12%
Trond Myklebust
3
0.33%
1
1.12%
Mika Kukkonen
3
0.33%
1
1.12%
Lafcadio Wluiki
2
0.22%
1
1.12%
Adrian Bunk
2
0.22%
2
2.25%
Arjan van de Ven
2
0.22%
2
2.25%
Harald Welte
1
0.11%
1
1.12%
Greg Kroah-Hartman
1
0.11%
1
1.12%
Dave Jones
1
0.11%
1
1.12%
Andries E. Brouwer
1
0.11%
1
1.12%
Sachin Kamat
1
0.11%
1
1.12%
Total
910
100.00%
89
100.00%
Directory: fs/proc

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