[deliverable/linux.git] / fs / proc / inode.c

/*
 *  linux/fs/proc/inode.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */

#include <linux/time.h>
#include <linux/proc_fs.h>
#include <linux/kernel.h>
#include <linux/pid_namespace.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/stat.h>
#include <linux/completion.h>
#include <linux/poll.h>
#include <linux/printk.h>
#include <linux/file.h>
#include <linux/limits.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/sysctl.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/mount.h>

#include <asm/uaccess.h>

#include "internal.h"

static void proc_evict_inode(struct inode *inode)
{
	struct proc_dir_entry *de;
	struct ctl_table_header *head;
	const struct proc_ns_operations *ns_ops;
	void *ns;

	truncate_inode_pages(&inode->i_data, 0);
	clear_inode(inode);

	/* Stop tracking associated processes */
	put_pid(PROC_I(inode)->pid);

	/* Let go of any associated proc directory entry */
	de = PROC_I(inode)->pde;
	if (de)
		pde_put(de);
	head = PROC_I(inode)->sysctl;
	if (head) {
		rcu_assign_pointer(PROC_I(inode)->sysctl, NULL);
		sysctl_head_put(head);
	}
	/* Release any associated namespace */
	ns_ops = PROC_I(inode)->ns_ops;
	ns = PROC_I(inode)->ns;
	if (ns_ops && ns)
		ns_ops->put(ns);
}

static struct kmem_cache * proc_inode_cachep;

static struct inode *proc_alloc_inode(struct super_block *sb)
{
	struct proc_inode *ei;
	struct inode *inode;

	ei = (struct proc_inode *)kmem_cache_alloc(proc_inode_cachep, GFP_KERNEL);
	if (!ei)
		return NULL;
	ei->pid = NULL;
	ei->fd = 0;
	ei->op.proc_get_link = NULL;
	ei->pde = NULL;
	ei->sysctl = NULL;
	ei->sysctl_entry = NULL;
	ei->ns = NULL;
	ei->ns_ops = NULL;
	inode = &ei->vfs_inode;
	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
	return inode;
}

static void proc_i_callback(struct rcu_head *head)
{
	struct inode *inode = container_of(head, struct inode, i_rcu);
	kmem_cache_free(proc_inode_cachep, PROC_I(inode));
}

static void proc_destroy_inode(struct inode *inode)
{
	call_rcu(&inode->i_rcu, proc_i_callback);
}

static void init_once(void *foo)
{
	struct proc_inode *ei = (struct proc_inode *) foo;

	inode_init_once(&ei->vfs_inode);
}

void __init proc_init_inodecache(void)
{
	proc_inode_cachep = kmem_cache_create("proc_inode_cache",
					     sizeof(struct proc_inode),
					     0, (SLAB_RECLAIM_ACCOUNT|
						SLAB_MEM_SPREAD|SLAB_PANIC),
					     init_once);
}

static int proc_show_options(struct seq_file *seq, struct dentry *root)
{
	struct super_block *sb = root->d_sb;
	struct pid_namespace *pid = sb->s_fs_info;

	if (!gid_eq(pid->pid_gid, GLOBAL_ROOT_GID))
		seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, pid->pid_gid));
	if (pid->hide_pid != 0)
		seq_printf(seq, ",hidepid=%u", pid->hide_pid);

	return 0;
}

static const struct super_operations proc_sops = {
	.alloc_inode	= proc_alloc_inode,
	.destroy_inode	= proc_destroy_inode,
	.drop_inode	= generic_delete_inode,
	.evict_inode	= proc_evict_inode,
	.statfs		= simple_statfs,
	.remount_fs	= proc_remount,
	.show_options	= proc_show_options,
};

enum {BIAS = -1U<<31};

static inline int use_pde(struct proc_dir_entry *pde)
{
	return atomic_inc_unless_negative(&pde->in_use);
}

static void unuse_pde(struct proc_dir_entry *pde)
{
	if (atomic_dec_return(&pde->in_use) == BIAS)
		complete(pde->pde_unload_completion);
}

/* pde is locked */
static void close_pdeo(struct proc_dir_entry *pde, struct pde_opener *pdeo)
{
	if (pdeo->closing) {
		/* somebody else is doing that, just wait */
		DECLARE_COMPLETION_ONSTACK(c);
		pdeo->c = &c;
		spin_unlock(&pde->pde_unload_lock);
		wait_for_completion(&c);
		spin_lock(&pde->pde_unload_lock);
	} else {
		struct file *file;
		pdeo->closing = 1;
		spin_unlock(&pde->pde_unload_lock);
		file = pdeo->file;
		pde->proc_fops->release(file_inode(file), file);
		spin_lock(&pde->pde_unload_lock);
		list_del_init(&pdeo->lh);
		if (pdeo->c)
			complete(pdeo->c);
		kfree(pdeo);
	}
}

void proc_entry_rundown(struct proc_dir_entry *de)
{
	DECLARE_COMPLETION_ONSTACK(c);
	/* Wait until all existing callers into module are done. */
	de->pde_unload_completion = &c;
	if (atomic_add_return(BIAS, &de->in_use) != BIAS)
		wait_for_completion(&c);

	spin_lock(&de->pde_unload_lock);
	while (!list_empty(&de->pde_openers)) {
		struct pde_opener *pdeo;
		pdeo = list_first_entry(&de->pde_openers, struct pde_opener, lh);
		close_pdeo(de, pdeo);
	}
	spin_unlock(&de->pde_unload_lock);
}

static loff_t proc_reg_llseek(struct file *file, loff_t offset, int whence)
{
	struct proc_dir_entry *pde = PDE(file_inode(file));
	loff_t rv = -EINVAL;
	if (use_pde(pde)) {
		loff_t (*llseek)(struct file *, loff_t, int);
		llseek = pde->proc_fops->llseek;
		if (!llseek)
			llseek = default_llseek;
		rv = llseek(file, offset, whence);
		unuse_pde(pde);
	}
	return rv;
}

static ssize_t proc_reg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
{
	ssize_t (*read)(struct file *, char __user *, size_t, loff_t *);
	struct proc_dir_entry *pde = PDE(file_inode(file));
	ssize_t rv = -EIO;
	if (use_pde(pde)) {
		read = pde->proc_fops->read;
		if (read)
			rv = read(file, buf, count, ppos);
		unuse_pde(pde);
	}
	return rv;
}

static ssize_t proc_reg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
{
	ssize_t (*write)(struct file *, const char __user *, size_t, loff_t *);
	struct proc_dir_entry *pde = PDE(file_inode(file));
	ssize_t rv = -EIO;
	if (use_pde(pde)) {
		write = pde->proc_fops->write;
		if (write)
			rv = write(file, buf, count, ppos);
		unuse_pde(pde);
	}
	return rv;
}

static unsigned int proc_reg_poll(struct file *file, struct poll_table_struct *pts)
{
	struct proc_dir_entry *pde = PDE(file_inode(file));
	unsigned int rv = DEFAULT_POLLMASK;
	unsigned int (*poll)(struct file *, struct poll_table_struct *);
	if (use_pde(pde)) {
		poll = pde->proc_fops->poll;
		if (poll)
			rv = poll(file, pts);
		unuse_pde(pde);
	}
	return rv;
}

static long proc_reg_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	struct proc_dir_entry *pde = PDE(file_inode(file));
	long rv = -ENOTTY;
	long (*ioctl)(struct file *, unsigned int, unsigned long);
	if (use_pde(pde)) {
		ioctl = pde->proc_fops->unlocked_ioctl;
		if (ioctl)
			rv = ioctl(file, cmd, arg);
		unuse_pde(pde);
	}
	return rv;
}

#ifdef CONFIG_COMPAT
static long proc_reg_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	struct proc_dir_entry *pde = PDE(file_inode(file));
	long rv = -ENOTTY;
	long (*compat_ioctl)(struct file *, unsigned int, unsigned long);
	if (use_pde(pde)) {
		compat_ioctl = pde->proc_fops->compat_ioctl;
		if (compat_ioctl)
			rv = compat_ioctl(file, cmd, arg);
		unuse_pde(pde);
	}
	return rv;
}
#endif

static int proc_reg_mmap(struct file *file, struct vm_area_struct *vma)
{
	struct proc_dir_entry *pde = PDE(file_inode(file));
	int rv = -EIO;
	int (*mmap)(struct file *, struct vm_area_struct *);
	if (use_pde(pde)) {
		mmap = pde->proc_fops->mmap;
		if (mmap)
			rv = mmap(file, vma);
		unuse_pde(pde);
	}
	return rv;
}

static int proc_reg_open(struct inode *inode, struct file *file)
{
	struct proc_dir_entry *pde = PDE(inode);
	int rv = 0;
	int (*open)(struct inode *, struct file *);
	int (*release)(struct inode *, struct file *);
	struct pde_opener *pdeo;

	/*
	 * What for, you ask? Well, we can have open, rmmod, remove_proc_entry
	 * sequence. ->release won't be called because ->proc_fops will be
	 * cleared. Depending on complexity of ->release, consequences vary.
	 *
	 * We can't wait for mercy when close will be done for real, it's
	 * deadlockable: rmmod foo </proc/foo . So, we're going to do ->release
	 * by hand in remove_proc_entry(). For this, save opener's credentials
	 * for later.
	 */
	pdeo = kzalloc(sizeof(struct pde_opener), GFP_KERNEL);
	if (!pdeo)
		return -ENOMEM;

	if (!use_pde(pde)) {
		kfree(pdeo);
		return -ENOENT;
	}
	open = pde->proc_fops->open;
	release = pde->proc_fops->release;

	if (open)
		rv = open(inode, file);

	if (rv == 0 && release) {
		/* To know what to release. */
		pdeo->file = file;
		/* Strictly for "too late" ->release in proc_reg_release(). */
		spin_lock(&pde->pde_unload_lock);
		list_add(&pdeo->lh, &pde->pde_openers);
		spin_unlock(&pde->pde_unload_lock);
	} else
		kfree(pdeo);

	unuse_pde(pde);
	return rv;
}

static int proc_reg_release(struct inode *inode, struct file *file)
{
	struct proc_dir_entry *pde = PDE(inode);
	struct pde_opener *pdeo;
	spin_lock(&pde->pde_unload_lock);
	list_for_each_entry(pdeo, &pde->pde_openers, lh) {
		if (pdeo->file == file) {
			close_pdeo(pde, pdeo);
			break;
		}
	}
	spin_unlock(&pde->pde_unload_lock);
	return 0;
}

static const struct file_operations proc_reg_file_ops = {
	.llseek		= proc_reg_llseek,
	.read		= proc_reg_read,
	.write		= proc_reg_write,
	.poll		= proc_reg_poll,
	.unlocked_ioctl	= proc_reg_unlocked_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl	= proc_reg_compat_ioctl,
#endif
	.mmap		= proc_reg_mmap,
	.open		= proc_reg_open,
	.release	= proc_reg_release,
};

#ifdef CONFIG_COMPAT
static const struct file_operations proc_reg_file_ops_no_compat = {
	.llseek		= proc_reg_llseek,
	.read		= proc_reg_read,
	.write		= proc_reg_write,
	.poll		= proc_reg_poll,
	.unlocked_ioctl	= proc_reg_unlocked_ioctl,
	.mmap		= proc_reg_mmap,
	.open		= proc_reg_open,
	.release	= proc_reg_release,
};
#endif

struct inode *proc_get_inode(struct super_block *sb, struct proc_dir_entry *de)
{
	struct inode *inode = new_inode_pseudo(sb);

	if (inode) {
		inode->i_ino = de->low_ino;
		inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
		PROC_I(inode)->pde = de;

		if (de->mode) {
			inode->i_mode = de->mode;
			inode->i_uid = de->uid;
			inode->i_gid = de->gid;
		}
		if (de->size)
			inode->i_size = de->size;
		if (de->nlink)
			set_nlink(inode, de->nlink);
		WARN_ON(!de->proc_iops);
		inode->i_op = de->proc_iops;
		if (de->proc_fops) {
			if (S_ISREG(inode->i_mode)) {
#ifdef CONFIG_COMPAT
				if (!de->proc_fops->compat_ioctl)
					inode->i_fop =
						&proc_reg_file_ops_no_compat;
				else
#endif
					inode->i_fop = &proc_reg_file_ops;
			} else {
				inode->i_fop = de->proc_fops;
			}
		}
	} else
	       pde_put(de);
	return inode;
}

int proc_fill_super(struct super_block *s)
{
	struct inode *root_inode;

	s->s_flags |= MS_NODIRATIME | MS_NOSUID | MS_NOEXEC;
	s->s_blocksize = 1024;
	s->s_blocksize_bits = 10;
	s->s_magic = PROC_SUPER_MAGIC;
	s->s_op = &proc_sops;
	s->s_time_gran = 1;
	
	pde_get(&proc_root);
	root_inode = proc_get_inode(s, &proc_root);
	if (!root_inode) {
		pr_err("proc_fill_super: get root inode failed\n");
		return -ENOMEM;
	}

	s->s_root = d_make_root(root_inode);
	if (!s->s_root) {
		pr_err("proc_fill_super: allocate dentry failed\n");
		return -ENOMEM;
	}

	return proc_setup_self(s);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/proc/inode.c
	3	*
	4	* Copyright (C) 1991, 1992 Linus Torvalds
	5	*/
	6
	7	#include <linux/time.h>
	8	#include <linux/proc_fs.h>
	9	#include <linux/kernel.h>
97412950	10	#include <linux/pid_namespace.h>
1da177e4 LT	11	#include <linux/mm.h>
	12	#include <linux/string.h>
	13	#include <linux/stat.h>
786d7e16	14	#include <linux/completion.h>
dd23aae4	15	#include <linux/poll.h>
87ebdc00	16	#include <linux/printk.h>
1da177e4 LT	17	#include <linux/file.h>
	18	#include <linux/limits.h>
	19	#include <linux/init.h>
	20	#include <linux/module.h>
9043476f	21	#include <linux/sysctl.h>
97412950	22	#include <linux/seq_file.h>
5a0e3ad6	23	#include <linux/slab.h>
97412950	24	#include <linux/mount.h>
1da177e4	25
1da177e4 LT	26	#include <asm/uaccess.h>
1da177e4 LT	27
fee781e6	28	#include "internal.h"
1da177e4	29
8267952b	30	static void proc_evict_inode(struct inode *inode)
1da177e4 LT	31	{
1da177e4 LT	32	struct proc_dir_entry *de;
dfef6dcd	33	struct ctl_table_header *head;
6b4e306a	34	const struct proc_ns_operations *ns_ops;
bf056bfa	35	void *ns;
1da177e4	36
fef26658	37	truncate_inode_pages(&inode->i_data, 0);
dbd5768f	38	clear_inode(inode);
fef26658	39
99f89551	40	/* Stop tracking associated processes */
13b41b09	41	put_pid(PROC_I(inode)->pid);
1da177e4 LT	42
	43	/* Let go of any associated proc directory entry */
	44	de = PROC_I(inode)->pde;
99b76233	45	if (de)
135d5655	46	pde_put(de);
dfef6dcd AV	47	head = PROC_I(inode)->sysctl;
	48	if (head) {
	49	rcu_assign_pointer(PROC_I(inode)->sysctl, NULL);
	50	sysctl_head_put(head);
	51	}
6b4e306a EB	52	/* Release any associated namespace */
6b4e306a EB	53	ns_ops = PROC_I(inode)->ns_ops;
bf056bfa EB	54	ns = PROC_I(inode)->ns;
	55	if (ns_ops && ns)
	56	ns_ops->put(ns);
1da177e4 LT	57	}
1da177e4 LT	58
e18b890b	59	static struct kmem_cache * proc_inode_cachep;
1da177e4 LT	60
	61	static struct inode proc_alloc_inode(struct super_block sb)
	62	{
	63	struct proc_inode *ei;
	64	struct inode *inode;
	65
e94b1766	66	ei = (struct proc_inode *)kmem_cache_alloc(proc_inode_cachep, GFP_KERNEL);
1da177e4 LT	67	if (!ei)
1da177e4 LT	68	return NULL;
13b41b09	69	ei->pid = NULL;
aed7a6c4	70	ei->fd = 0;
1da177e4 LT	71	ei->op.proc_get_link = NULL;
1da177e4 LT	72	ei->pde = NULL;
9043476f AV	73	ei->sysctl = NULL;
9043476f AV	74	ei->sysctl_entry = NULL;
6b4e306a EB	75	ei->ns = NULL;
6b4e306a EB	76	ei->ns_ops = NULL;
1da177e4 LT	77	inode = &ei->vfs_inode;
	78	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
	79	return inode;
	80	}
	81
fa0d7e3d	82	static void proc_i_callback(struct rcu_head *head)
1da177e4	83	{
fa0d7e3d	84	struct inode *inode = container_of(head, struct inode, i_rcu);
1da177e4 LT	85	kmem_cache_free(proc_inode_cachep, PROC_I(inode));
	86	}
	87
fa0d7e3d NP	88	static void proc_destroy_inode(struct inode *inode)
	89	{
	90	call_rcu(&inode->i_rcu, proc_i_callback);
	91	}
	92
51cc5068	93	static void init_once(void *foo)
1da177e4 LT	94	{
	95	struct proc_inode ei = (struct proc_inode ) foo;
	96
a35afb83	97	inode_init_once(&ei->vfs_inode);
1da177e4	98	}
20c2df83	99
5bcd7ff9	100	void __init proc_init_inodecache(void)
1da177e4 LT	101	{
	102	proc_inode_cachep = kmem_cache_create("proc_inode_cache",
	103	sizeof(struct proc_inode),
fffb60f9	104	0, (SLAB_RECLAIM_ACCOUNT\|
040b5c6f	105	SLAB_MEM_SPREAD\|SLAB_PANIC),
20c2df83	106	init_once);
1da177e4 LT	107	}
1da177e4 LT	108
97412950 VK	109	static int proc_show_options(struct seq_file seq, struct dentry root)
97412950 VK	110	{
0499680a VK	111	struct super_block *sb = root->d_sb;
	112	struct pid_namespace *pid = sb->s_fs_info;
	113
dcb0f222 EB	114	if (!gid_eq(pid->pid_gid, GLOBAL_ROOT_GID))
dcb0f222 EB	115	seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, pid->pid_gid));
0499680a VK	116	if (pid->hide_pid != 0)
	117	seq_printf(seq, ",hidepid=%u", pid->hide_pid);
	118
97412950 VK	119	return 0;
	120	}
	121
ee9b6d61	122	static const struct super_operations proc_sops = {
1da177e4 LT	123	.alloc_inode = proc_alloc_inode,
1da177e4 LT	124	.destroy_inode = proc_destroy_inode,
1da177e4	125	.drop_inode = generic_delete_inode,
8267952b	126	.evict_inode = proc_evict_inode,
1da177e4	127	.statfs = simple_statfs,
97412950 VK	128	.remount_fs = proc_remount,
97412950 VK	129	.show_options = proc_show_options,
1da177e4 LT	130	};
1da177e4 LT	131
866ad9a7 AV	132	enum {BIAS = -1U<<31};
	133
	134	static inline int use_pde(struct proc_dir_entry *pde)
	135	{
05c0ae21	136	return atomic_inc_unless_negative(&pde->in_use);
881adb85 AD	137	}
881adb85 AD	138
866ad9a7	139	static void unuse_pde(struct proc_dir_entry *pde)
881adb85	140	{
05c0ae21 AV	141	if (atomic_dec_return(&pde->in_use) == BIAS)
05c0ae21 AV	142	complete(pde->pde_unload_completion);
786d7e16 AD	143	}
786d7e16 AD	144
ca469f35 AV	145	/* pde is locked */
	146	static void close_pdeo(struct proc_dir_entry pde, struct pde_opener pdeo)
	147	{
05c0ae21	148	if (pdeo->closing) {
ca469f35	149	/* somebody else is doing that, just wait */
05c0ae21 AV	150	DECLARE_COMPLETION_ONSTACK(c);
05c0ae21 AV	151	pdeo->c = &c;
ca469f35	152	spin_unlock(&pde->pde_unload_lock);
05c0ae21	153	wait_for_completion(&c);
ca469f35	154	spin_lock(&pde->pde_unload_lock);
ca469f35 AV	155	} else {
ca469f35 AV	156	struct file *file;
05c0ae21	157	pdeo->closing = 1;
ca469f35 AV	158	spin_unlock(&pde->pde_unload_lock);
	159	file = pdeo->file;
	160	pde->proc_fops->release(file_inode(file), file);
	161	spin_lock(&pde->pde_unload_lock);
	162	list_del_init(&pdeo->lh);
05c0ae21 AV	163	if (pdeo->c)
05c0ae21 AV	164	complete(pdeo->c);
ca469f35	165	kfree(pdeo);
05c0ae21	166	}
ca469f35 AV	167	}
ca469f35 AV	168
866ad9a7	169	void proc_entry_rundown(struct proc_dir_entry *de)
786d7e16	170	{
05c0ae21	171	DECLARE_COMPLETION_ONSTACK(c);
866ad9a7	172	/* Wait until all existing callers into module are done. */
05c0ae21 AV	173	de->pde_unload_completion = &c;
	174	if (atomic_add_return(BIAS, &de->in_use) != BIAS)
	175	wait_for_completion(&c);
786d7e16	176
05c0ae21	177	spin_lock(&de->pde_unload_lock);
866ad9a7 AV	178	while (!list_empty(&de->pde_openers)) {
866ad9a7 AV	179	struct pde_opener *pdeo;
866ad9a7	180	pdeo = list_first_entry(&de->pde_openers, struct pde_opener, lh);
ca469f35	181	close_pdeo(de, pdeo);
866ad9a7 AV	182	}
866ad9a7 AV	183	spin_unlock(&de->pde_unload_lock);
786d7e16 AD	184	}
786d7e16 AD	185
866ad9a7 AV	186	static loff_t proc_reg_llseek(struct file *file, loff_t offset, int whence)
	187	{
	188	struct proc_dir_entry *pde = PDE(file_inode(file));
	189	loff_t rv = -EINVAL;
	190	if (use_pde(pde)) {
	191	loff_t (llseek)(struct file , loff_t, int);
	192	llseek = pde->proc_fops->llseek;
	193	if (!llseek)
	194	llseek = default_llseek;
	195	rv = llseek(file, offset, whence);
	196	unuse_pde(pde);
	197	}
786d7e16 AD	198	return rv;
	199	}
	200
866ad9a7	201	static ssize_t proc_reg_read(struct file file, char __user buf, size_t count, loff_t *ppos)
786d7e16	202	{
866ad9a7	203	ssize_t (read)(struct file , char __user , size_t, loff_t );
496ad9aa	204	struct proc_dir_entry *pde = PDE(file_inode(file));
786d7e16	205	ssize_t rv = -EIO;
866ad9a7 AV	206	if (use_pde(pde)) {
	207	read = pde->proc_fops->read;
	208	if (read)
	209	rv = read(file, buf, count, ppos);
	210	unuse_pde(pde);
786d7e16	211	}
866ad9a7 AV	212	return rv;
866ad9a7 AV	213	}
786d7e16	214
866ad9a7 AV	215	static ssize_t proc_reg_write(struct file file, const char __user buf, size_t count, loff_t *ppos)
	216	{
	217	ssize_t (write)(struct file , const char __user , size_t, loff_t );
	218	struct proc_dir_entry *pde = PDE(file_inode(file));
	219	ssize_t rv = -EIO;
	220	if (use_pde(pde)) {
	221	write = pde->proc_fops->write;
	222	if (write)
	223	rv = write(file, buf, count, ppos);
	224	unuse_pde(pde);
	225	}
786d7e16 AD	226	return rv;
	227	}
	228
	229	static unsigned int proc_reg_poll(struct file file, struct poll_table_struct pts)
	230	{
496ad9aa	231	struct proc_dir_entry *pde = PDE(file_inode(file));
dd23aae4	232	unsigned int rv = DEFAULT_POLLMASK;
786d7e16	233	unsigned int (poll)(struct file , struct poll_table_struct *);
866ad9a7 AV	234	if (use_pde(pde)) {
	235	poll = pde->proc_fops->poll;
	236	if (poll)
	237	rv = poll(file, pts);
	238	unuse_pde(pde);
786d7e16	239	}
786d7e16 AD	240	return rv;
	241	}
	242
	243	static long proc_reg_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
	244	{
496ad9aa	245	struct proc_dir_entry *pde = PDE(file_inode(file));
786d7e16	246	long rv = -ENOTTY;
b19dd42f	247	long (ioctl)(struct file , unsigned int, unsigned long);
866ad9a7 AV	248	if (use_pde(pde)) {
	249	ioctl = pde->proc_fops->unlocked_ioctl;
	250	if (ioctl)
	251	rv = ioctl(file, cmd, arg);
	252	unuse_pde(pde);
786d7e16	253	}
786d7e16 AD	254	return rv;
	255	}
	256
	257	#ifdef CONFIG_COMPAT
	258	static long proc_reg_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
	259	{
496ad9aa	260	struct proc_dir_entry *pde = PDE(file_inode(file));
786d7e16 AD	261	long rv = -ENOTTY;
786d7e16 AD	262	long (compat_ioctl)(struct file , unsigned int, unsigned long);
866ad9a7 AV	263	if (use_pde(pde)) {
	264	compat_ioctl = pde->proc_fops->compat_ioctl;
	265	if (compat_ioctl)
	266	rv = compat_ioctl(file, cmd, arg);
	267	unuse_pde(pde);
786d7e16	268	}
786d7e16 AD	269	return rv;
	270	}
	271	#endif
	272
	273	static int proc_reg_mmap(struct file file, struct vm_area_struct vma)
	274	{
496ad9aa	275	struct proc_dir_entry *pde = PDE(file_inode(file));
786d7e16 AD	276	int rv = -EIO;
786d7e16 AD	277	int (mmap)(struct file , struct vm_area_struct *);
866ad9a7 AV	278	if (use_pde(pde)) {
	279	mmap = pde->proc_fops->mmap;
	280	if (mmap)
	281	rv = mmap(file, vma);
	282	unuse_pde(pde);
786d7e16	283	}
786d7e16 AD	284	return rv;
	285	}
	286
	287	static int proc_reg_open(struct inode inode, struct file file)
	288	{
	289	struct proc_dir_entry *pde = PDE(inode);
	290	int rv = 0;
	291	int (open)(struct inode , struct file *);
881adb85 AD	292	int (release)(struct inode , struct file *);
	293	struct pde_opener *pdeo;
	294
	295	/*
	296	* What for, you ask? Well, we can have open, rmmod, remove_proc_entry
	297	* sequence. ->release won't be called because ->proc_fops will be
	298	* cleared. Depending on complexity of ->release, consequences vary.
	299	*
	300	* We can't wait for mercy when close will be done for real, it's
	301	* deadlockable: rmmod foo </proc/foo . So, we're going to do ->release
	302	* by hand in remove_proc_entry(). For this, save opener's credentials
	303	* for later.
	304	*/
05c0ae21	305	pdeo = kzalloc(sizeof(struct pde_opener), GFP_KERNEL);
881adb85 AD	306	if (!pdeo)
881adb85 AD	307	return -ENOMEM;
786d7e16	308
866ad9a7	309	if (!use_pde(pde)) {
881adb85	310	kfree(pdeo);
d2857e79	311	return -ENOENT;
786d7e16	312	}
786d7e16	313	open = pde->proc_fops->open;
881adb85	314	release = pde->proc_fops->release;
786d7e16 AD	315
	316	if (open)
	317	rv = open(inode, file);
	318
881adb85 AD	319	if (rv == 0 && release) {
881adb85 AD	320	/* To know what to release. */
881adb85 AD	321	pdeo->file = file;
881adb85 AD	322	/* Strictly for "too late" ->release in proc_reg_release(). */
05c0ae21	323	spin_lock(&pde->pde_unload_lock);
881adb85	324	list_add(&pdeo->lh, &pde->pde_openers);
05c0ae21	325	spin_unlock(&pde->pde_unload_lock);
881adb85 AD	326	} else
881adb85 AD	327	kfree(pdeo);
05c0ae21 AV	328
05c0ae21 AV	329	unuse_pde(pde);
786d7e16 AD	330	return rv;
	331	}
	332
	333	static int proc_reg_release(struct inode inode, struct file file)
	334	{
	335	struct proc_dir_entry *pde = PDE(inode);
881adb85	336	struct pde_opener *pdeo;
786d7e16	337	spin_lock(&pde->pde_unload_lock);
ca469f35 AV	338	list_for_each_entry(pdeo, &pde->pde_openers, lh) {
	339	if (pdeo->file == file) {
	340	close_pdeo(pde, pdeo);
	341	break;
	342	}
881adb85	343	}
786d7e16	344	spin_unlock(&pde->pde_unload_lock);
ca469f35	345	return 0;
786d7e16 AD	346	}
	347
	348	static const struct file_operations proc_reg_file_ops = {
	349	.llseek = proc_reg_llseek,
	350	.read = proc_reg_read,
	351	.write = proc_reg_write,
	352	.poll = proc_reg_poll,
	353	.unlocked_ioctl = proc_reg_unlocked_ioctl,
	354	#ifdef CONFIG_COMPAT
	355	.compat_ioctl = proc_reg_compat_ioctl,
	356	#endif
	357	.mmap = proc_reg_mmap,
	358	.open = proc_reg_open,
	359	.release = proc_reg_release,
	360	};
	361
778f3dd5 DM	362	#ifdef CONFIG_COMPAT
	363	static const struct file_operations proc_reg_file_ops_no_compat = {
	364	.llseek = proc_reg_llseek,
	365	.read = proc_reg_read,
	366	.write = proc_reg_write,
	367	.poll = proc_reg_poll,
	368	.unlocked_ioctl = proc_reg_unlocked_ioctl,
	369	.mmap = proc_reg_mmap,
	370	.open = proc_reg_open,
	371	.release = proc_reg_release,
	372	};
	373	#endif
	374
6d1b6e4e	375	struct inode proc_get_inode(struct super_block sb, struct proc_dir_entry *de)
1da177e4	376	{
51f0885e	377	struct inode *inode = new_inode_pseudo(sb);
1da177e4	378
51f0885e LT	379	if (inode) {
51f0885e LT	380	inode->i_ino = de->low_ino;
a1d4aebb	381	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
a1d4aebb	382	PROC_I(inode)->pde = de;
5e971dce AD	383
	384	if (de->mode) {
	385	inode->i_mode = de->mode;
	386	inode->i_uid = de->uid;
	387	inode->i_gid = de->gid;
	388	}
	389	if (de->size)
	390	inode->i_size = de->size;
	391	if (de->nlink)
bfe86848	392	set_nlink(inode, de->nlink);
b6cdc731 AV	393	WARN_ON(!de->proc_iops);
b6cdc731 AV	394	inode->i_op = de->proc_iops;
5e971dce AD	395	if (de->proc_fops) {
5e971dce AD	396	if (S_ISREG(inode->i_mode)) {
778f3dd5	397	#ifdef CONFIG_COMPAT
5e971dce AD	398	if (!de->proc_fops->compat_ioctl)
	399	inode->i_fop =
	400	&proc_reg_file_ops_no_compat;
	401	else
778f3dd5	402	#endif
5e971dce AD	403	inode->i_fop = &proc_reg_file_ops;
	404	} else {
	405	inode->i_fop = de->proc_fops;
778f3dd5	406	}
786d7e16	407	}
99b76233	408	} else
135d5655	409	pde_put(de);
1da177e4	410	return inode;
d3d009cb	411	}
1da177e4	412
07543f5c	413	int proc_fill_super(struct super_block *s)
1da177e4	414	{
87e0aab3 MP	415	struct inode *root_inode;
87e0aab3 MP	416
92d03285	417	s->s_flags \|= MS_NODIRATIME \| MS_NOSUID \| MS_NOEXEC;
1da177e4 LT	418	s->s_blocksize = 1024;
	419	s->s_blocksize_bits = 10;
	420	s->s_magic = PROC_SUPER_MAGIC;
	421	s->s_op = &proc_sops;
	422	s->s_time_gran = 1;
	423
135d5655	424	pde_get(&proc_root);
87e0aab3 MP	425	root_inode = proc_get_inode(s, &proc_root);
87e0aab3 MP	426	if (!root_inode) {
87ebdc00	427	pr_err("proc_fill_super: get root inode failed\n");
87e0aab3 MP	428	return -ENOMEM;
87e0aab3 MP	429	}
1da177e4	430
87e0aab3 MP	431	s->s_root = d_make_root(root_inode);
87e0aab3 MP	432	if (!s->s_root) {
87ebdc00	433	pr_err("proc_fill_super: allocate dentry failed\n");
87e0aab3 MP	434	return -ENOMEM;
	435	}
	436
021ada7d	437	return proc_setup_self(s);
1da177e4	438	}