[linux-block.git] / security / tomoyo / realpath.c

/*
 * security/tomoyo/realpath.c
 *
 * Get the canonicalized absolute pathnames. The basis for TOMOYO.
 *
 * Copyright (C) 2005-2009  NTT DATA CORPORATION
 *
 * Version: 2.2.0   2009/04/01
 *
 */

#include <linux/types.h>
#include <linux/mount.h>
#include <linux/mnt_namespace.h>
#include <linux/fs_struct.h>
#include <linux/hash.h>
#include <linux/magic.h>
#include "common.h"

/**
 * tomoyo_encode: Convert binary string to ascii string.
 *
 * @buffer:  Buffer for ASCII string.
 * @buflen:  Size of @buffer.
 * @str:     Binary string.
 *
 * Returns 0 on success, -ENOMEM otherwise.
 */
int tomoyo_encode(char *buffer, int buflen, const char *str)
{
	while (1) {
		const unsigned char c = *(unsigned char *) str++;

		if (tomoyo_is_valid(c)) {
			if (--buflen <= 0)
				break;
			*buffer++ = (char) c;
			if (c != '\\')
				continue;
			if (--buflen <= 0)
				break;
			*buffer++ = (char) c;
			continue;
		}
		if (!c) {
			if (--buflen <= 0)
				break;
			*buffer = '\0';
			return 0;
		}
		buflen -= 4;
		if (buflen <= 0)
			break;
		*buffer++ = '\\';
		*buffer++ = (c >> 6) + '0';
		*buffer++ = ((c >> 3) & 7) + '0';
		*buffer++ = (c & 7) + '0';
	}
	return -ENOMEM;
}

/**
 * tomoyo_realpath_from_path2 - Returns realpath(3) of the given dentry but ignores chroot'ed root.
 *
 * @path:        Pointer to "struct path".
 * @newname:     Pointer to buffer to return value in.
 * @newname_len: Size of @newname.
 *
 * Returns 0 on success, negative value otherwise.
 *
 * If dentry is a directory, trailing '/' is appended.
 * Characters out of 0x20 < c < 0x7F range are converted to
 * \ooo style octal string.
 * Character \ is converted to \\ string.
 */
int tomoyo_realpath_from_path2(struct path *path, char *newname,
			       int newname_len)
{
	int error = -ENOMEM;
	struct dentry *dentry = path->dentry;
	char *sp;

	if (!dentry || !path->mnt || !newname || newname_len <= 2048)
		return -EINVAL;
	if (dentry->d_op && dentry->d_op->d_dname) {
		/* For "socket:[\$]" and "pipe:[\$]". */
		static const int offset = 1536;
		sp = dentry->d_op->d_dname(dentry, newname + offset,
					   newname_len - offset);
	} else {
		/* Taken from d_namespace_path(). */
		struct path root;
		struct path ns_root = { };
		struct path tmp;

		read_lock(&current->fs->lock);
		root = current->fs->root;
		path_get(&root);
		read_unlock(&current->fs->lock);
		spin_lock(&vfsmount_lock);
		if (root.mnt && root.mnt->mnt_ns)
			ns_root.mnt = mntget(root.mnt->mnt_ns->root);
		if (ns_root.mnt)
			ns_root.dentry = dget(ns_root.mnt->mnt_root);
		spin_unlock(&vfsmount_lock);
		spin_lock(&dcache_lock);
		tmp = ns_root;
		sp = __d_path(path, &tmp, newname, newname_len);
		spin_unlock(&dcache_lock);
		path_put(&root);
		path_put(&ns_root);
		/* Prepend "/proc" prefix if using internal proc vfs mount. */
		if (!IS_ERR(sp) && (path->mnt->mnt_parent == path->mnt) &&
		    (path->mnt->mnt_sb->s_magic == PROC_SUPER_MAGIC)) {
			sp -= 5;
			if (sp >= newname)
				memcpy(sp, "/proc", 5);
			else
				sp = ERR_PTR(-ENOMEM);
		}
	}
	if (IS_ERR(sp))
		error = PTR_ERR(sp);
	else
		error = tomoyo_encode(newname, sp - newname, sp);
	/* Append trailing '/' if dentry is a directory. */
	if (!error && dentry->d_inode && S_ISDIR(dentry->d_inode->i_mode)
	    && *newname) {
		sp = newname + strlen(newname);
		if (*(sp - 1) != '/') {
			if (sp < newname + newname_len - 4) {
				*sp++ = '/';
				*sp = '\0';
			} else {
				error = -ENOMEM;
			}
		}
	}
	if (error)
		printk(KERN_WARNING "tomoyo_realpath: Pathname too long.\n");
	return error;
}

/**
 * tomoyo_realpath_from_path - Returns realpath(3) of the given pathname but ignores chroot'ed root.
 *
 * @path: Pointer to "struct path".
 *
 * Returns the realpath of the given @path on success, NULL otherwise.
 *
 * These functions use kzalloc(), so the caller must call kfree()
 * if these functions didn't return NULL.
 */
char *tomoyo_realpath_from_path(struct path *path)
{
	char *buf = kzalloc(sizeof(struct tomoyo_page_buffer), GFP_KERNEL);

	BUILD_BUG_ON(sizeof(struct tomoyo_page_buffer)
		     <= TOMOYO_MAX_PATHNAME_LEN - 1);
	if (!buf)
		return NULL;
	if (tomoyo_realpath_from_path2(path, buf,
				       TOMOYO_MAX_PATHNAME_LEN - 1) == 0)
		return buf;
	kfree(buf);
	return NULL;
}

/**
 * tomoyo_realpath - Get realpath of a pathname.
 *
 * @pathname: The pathname to solve.
 *
 * Returns the realpath of @pathname on success, NULL otherwise.
 */
char *tomoyo_realpath(const char *pathname)
{
	struct path path;

	if (pathname && kern_path(pathname, LOOKUP_FOLLOW, &path) == 0) {
		char *buf = tomoyo_realpath_from_path(&path);
		path_put(&path);
		return buf;
	}
	return NULL;
}

/**
 * tomoyo_realpath_nofollow - Get realpath of a pathname.
 *
 * @pathname: The pathname to solve.
 *
 * Returns the realpath of @pathname on success, NULL otherwise.
 */
char *tomoyo_realpath_nofollow(const char *pathname)
{
	struct path path;

	if (pathname && kern_path(pathname, 0, &path) == 0) {
		char *buf = tomoyo_realpath_from_path(&path);
		path_put(&path);
		return buf;
	}
	return NULL;
}

/* Memory allocated for non-string data. */
static unsigned int tomoyo_allocated_memory_for_elements;
/* Quota for holding non-string data. */
static unsigned int tomoyo_quota_for_elements;

/**
 * tomoyo_memory_ok - Check memory quota.
 *
 * @ptr: Pointer to allocated memory.
 *
 * Returns true on success, false otherwise.
 *
 * Caller holds tomoyo_policy_lock.
 * Memory pointed by @ptr will be zeroed on success.
 */
bool tomoyo_memory_ok(void *ptr)
{
	int allocated_len = ptr ? ksize(ptr) : 0;
	bool result = false;
	if (!ptr || (tomoyo_quota_for_elements &&
		     tomoyo_allocated_memory_for_elements
		     + allocated_len > tomoyo_quota_for_elements)) {
		printk(KERN_WARNING "ERROR: Out of memory "
		       "for tomoyo_alloc_element().\n");
		if (!tomoyo_policy_loaded)
			panic("MAC Initialization failed.\n");
	} else {
		result = true;
		tomoyo_allocated_memory_for_elements += allocated_len;
		memset(ptr, 0, allocated_len);
	}
	return result;
}

/* Memory allocated for string data in bytes. */
static unsigned int tomoyo_allocated_memory_for_savename;
/* Quota for holding string data in bytes. */
static unsigned int tomoyo_quota_for_savename;

/*
 * tomoyo_name_list is used for holding string data used by TOMOYO.
 * Since same string data is likely used for multiple times (e.g.
 * "/lib/libc-2.5.so"), TOMOYO shares string data in the form of
 * "const struct tomoyo_path_info *".
 */
static struct list_head tomoyo_name_list[TOMOYO_MAX_HASH];

/**
 * tomoyo_get_name - Allocate permanent memory for string data.
 *
 * @name: The string to store into the permernent memory.
 *
 * Returns pointer to "struct tomoyo_path_info" on success, NULL otherwise.
 */
const struct tomoyo_path_info *tomoyo_get_name(const char *name)
{
	static DEFINE_MUTEX(lock);
	struct tomoyo_name_entry *ptr;
	unsigned int hash;
	int len;
	int allocated_len;
	struct list_head *head;

	if (!name)
		return NULL;
	len = strlen(name) + 1;
	hash = full_name_hash((const unsigned char *) name, len - 1);
	head = &tomoyo_name_list[hash_long(hash, TOMOYO_HASH_BITS)];
	mutex_lock(&lock);
	list_for_each_entry(ptr, head, list) {
		if (hash != ptr->entry.hash || strcmp(name, ptr->entry.name))
			continue;
		atomic_inc(&ptr->users);
		goto out;
	}
	ptr = kzalloc(sizeof(*ptr) + len, GFP_KERNEL);
	allocated_len = ptr ? ksize(ptr) : 0;
	if (!ptr || (tomoyo_quota_for_savename &&
		     tomoyo_allocated_memory_for_savename + allocated_len
		     > tomoyo_quota_for_savename)) {
		kfree(ptr);
		printk(KERN_WARNING "ERROR: Out of memory "
		       "for tomoyo_get_name().\n");
		if (!tomoyo_policy_loaded)
			panic("MAC Initialization failed.\n");
		ptr = NULL;
		goto out;
	}
	tomoyo_allocated_memory_for_savename += allocated_len;
	ptr->entry.name = ((char *) ptr) + sizeof(*ptr);
	memmove((char *) ptr->entry.name, name, len);
	atomic_set(&ptr->users, 1);
	tomoyo_fill_path_info(&ptr->entry);
	list_add_tail(&ptr->list, head);
 out:
	mutex_unlock(&lock);
	return ptr ? &ptr->entry : NULL;
}

/**
 * tomoyo_realpath_init - Initialize realpath related code.
 */
void __init tomoyo_realpath_init(void)
{
	int i;

	BUILD_BUG_ON(TOMOYO_MAX_PATHNAME_LEN > PATH_MAX);
	for (i = 0; i < TOMOYO_MAX_HASH; i++)
		INIT_LIST_HEAD(&tomoyo_name_list[i]);
	INIT_LIST_HEAD(&tomoyo_kernel_domain.acl_info_list);
	tomoyo_kernel_domain.domainname = tomoyo_get_name(TOMOYO_ROOT_NAME);
	/*
	 * tomoyo_read_lock() is not needed because this function is
	 * called before the first "delete" request.
	 */
	list_add_tail_rcu(&tomoyo_kernel_domain.list, &tomoyo_domain_list);
	if (tomoyo_find_domain(TOMOYO_ROOT_NAME) != &tomoyo_kernel_domain)
		panic("Can't register tomoyo_kernel_domain");
}

/**
 * tomoyo_read_memory_counter - Check for memory usage in bytes.
 *
 * @head: Pointer to "struct tomoyo_io_buffer".
 *
 * Returns memory usage.
 */
int tomoyo_read_memory_counter(struct tomoyo_io_buffer *head)
{
	if (!head->read_eof) {
		const unsigned int shared
			= tomoyo_allocated_memory_for_savename;
		const unsigned int private
			= tomoyo_allocated_memory_for_elements;
		char buffer[64];

		memset(buffer, 0, sizeof(buffer));
		if (tomoyo_quota_for_savename)
			snprintf(buffer, sizeof(buffer) - 1,
				 "   (Quota: %10u)",
				 tomoyo_quota_for_savename);
		else
			buffer[0] = '\0';
		tomoyo_io_printf(head, "Shared:  %10u%s\n", shared, buffer);
		if (tomoyo_quota_for_elements)
			snprintf(buffer, sizeof(buffer) - 1,
				 "   (Quota: %10u)",
				 tomoyo_quota_for_elements);
		else
			buffer[0] = '\0';
		tomoyo_io_printf(head, "Private: %10u%s\n", private, buffer);
		tomoyo_io_printf(head, "Total:   %10u\n", shared + private);
		head->read_eof = true;
	}
	return 0;
}

/**
 * tomoyo_write_memory_quota - Set memory quota.
 *
 * @head: Pointer to "struct tomoyo_io_buffer".
 *
 * Returns 0.
 */
int tomoyo_write_memory_quota(struct tomoyo_io_buffer *head)
{
	char *data = head->write_buf;
	unsigned int size;

	if (sscanf(data, "Shared: %u", &size) == 1)
		tomoyo_quota_for_savename = size;
	else if (sscanf(data, "Private: %u", &size) == 1)
		tomoyo_quota_for_elements = size;
	return 0;
}
Commit	Line	Data
c73bd6d4 KT	1	/*
	2	* security/tomoyo/realpath.c
	3	*
	4	* Get the canonicalized absolute pathnames. The basis for TOMOYO.
	5	*
	6	* Copyright (C) 2005-2009 NTT DATA CORPORATION
	7	*
39826a1e	8	* Version: 2.2.0 2009/04/01
c73bd6d4 KT	9	*
	10	*/
	11
	12	#include <linux/types.h>
	13	#include <linux/mount.h>
	14	#include <linux/mnt_namespace.h>
5ad4e53b	15	#include <linux/fs_struct.h>
024e1a49	16	#include <linux/hash.h>
67fa4880	17	#include <linux/magic.h>
c73bd6d4	18	#include "common.h"
c73bd6d4 KT	19
	20	/**
	21	* tomoyo_encode: Convert binary string to ascii string.
	22	*
	23	* @buffer: Buffer for ASCII string.
	24	* @buflen: Size of @buffer.
	25	* @str: Binary string.
	26	*
	27	* Returns 0 on success, -ENOMEM otherwise.
	28	*/
	29	int tomoyo_encode(char buffer, int buflen, const char str)
	30	{
	31	while (1) {
	32	const unsigned char c = (unsigned char ) str++;
	33
	34	if (tomoyo_is_valid(c)) {
	35	if (--buflen <= 0)
	36	break;
	37	*buffer++ = (char) c;
	38	if (c != '\\')
	39	continue;
	40	if (--buflen <= 0)
	41	break;
	42	*buffer++ = (char) c;
	43	continue;
	44	}
	45	if (!c) {
	46	if (--buflen <= 0)
	47	break;
	48	*buffer = '\0';
	49	return 0;
	50	}
	51	buflen -= 4;
	52	if (buflen <= 0)
	53	break;
	54	*buffer++ = '\\';
	55	*buffer++ = (c >> 6) + '0';
	56	*buffer++ = ((c >> 3) & 7) + '0';
	57	*buffer++ = (c & 7) + '0';
	58	}
	59	return -ENOMEM;
	60	}
	61
	62	/**
	63	* tomoyo_realpath_from_path2 - Returns realpath(3) of the given dentry but ignores chroot'ed root.
	64	*
	65	* @path: Pointer to "struct path".
	66	* @newname: Pointer to buffer to return value in.
	67	* @newname_len: Size of @newname.
	68	*
	69	* Returns 0 on success, negative value otherwise.
	70	*
	71	* If dentry is a directory, trailing '/' is appended.
	72	* Characters out of 0x20 < c < 0x7F range are converted to
	73	* \ooo style octal string.
	74	* Character \ is converted to \\ string.
	75	*/
	76	int tomoyo_realpath_from_path2(struct path path, char newname,
	77	int newname_len)
	78	{
	79	int error = -ENOMEM;
	80	struct dentry *dentry = path->dentry;
	81	char *sp;
	82
83	if (!dentry \|\| !path->mnt \|\| !newname \|\| newname_len <= 2048)
84	return -EINVAL;
85	if (dentry->d_op && dentry->d_op->d_dname) {
86	/* For "socket:[\$]" and "pipe:[\$]". */
87	static const int offset = 1536;
88	sp = dentry->d_op->d_dname(dentry, newname + offset,
89	newname_len - offset);
90	} else {
91	/* Taken from d_namespace_path(). */
92	struct path root;
93	struct path ns_root = { };
94	struct path tmp;
95
96	read_lock(&current->fs->lock);
97	root = current->fs->root;
98	path_get(&root);
99	read_unlock(&current->fs->lock);
100	spin_lock(&vfsmount_lock);
101	if (root.mnt && root.mnt->mnt_ns)
102	ns_root.mnt = mntget(root.mnt->mnt_ns->root);
103	if (ns_root.mnt)
104	ns_root.dentry = dget(ns_root.mnt->mnt_root);
105	spin_unlock(&vfsmount_lock);
106	spin_lock(&dcache_lock);
107	tmp = ns_root;
108	sp = __d_path(path, &tmp, newname, newname_len);
109	spin_unlock(&dcache_lock);
110	path_put(&root);
111	path_put(&ns_root);
a4054b6b EB	112	/* Prepend "/proc" prefix if using internal proc vfs mount. */
a4054b6b EB	113	if (!IS_ERR(sp) && (path->mnt->mnt_parent == path->mnt) &&
67fa4880	114	(path->mnt->mnt_sb->s_magic == PROC_SUPER_MAGIC)) {
a4054b6b EB	115	sp -= 5;
	116	if (sp >= newname)
	117	memcpy(sp, "/proc", 5);
	118	else
	119	sp = ERR_PTR(-ENOMEM);
	120	}
c73bd6d4 KT	121	}
	122	if (IS_ERR(sp))
	123	error = PTR_ERR(sp);
	124	else
	125	error = tomoyo_encode(newname, sp - newname, sp);
	126	/* Append trailing '/' if dentry is a directory. */
	127	if (!error && dentry->d_inode && S_ISDIR(dentry->d_inode->i_mode)
	128	&& *newname) {
	129	sp = newname + strlen(newname);
	130	if (*(sp - 1) != '/') {
	131	if (sp < newname + newname_len - 4) {
	132	*sp++ = '/';
	133	*sp = '\0';
	134	} else {
	135	error = -ENOMEM;
	136	}
	137	}
	138	}
	139	if (error)
	140	printk(KERN_WARNING "tomoyo_realpath: Pathname too long.\n");
	141	return error;
	142	}
	143
	144	/**
	145	* tomoyo_realpath_from_path - Returns realpath(3) of the given pathname but ignores chroot'ed root.
	146	*
	147	* @path: Pointer to "struct path".
	148	*
	149	* Returns the realpath of the given @path on success, NULL otherwise.
	150	*
8e2d39a1	151	* These functions use kzalloc(), so the caller must call kfree()
c73bd6d4 KT	152	* if these functions didn't return NULL.
	153	*/
	154	char tomoyo_realpath_from_path(struct path path)
	155	{
8e2d39a1	156	char *buf = kzalloc(sizeof(struct tomoyo_page_buffer), GFP_KERNEL);
c73bd6d4 KT	157
	158	BUILD_BUG_ON(sizeof(struct tomoyo_page_buffer)
	159	<= TOMOYO_MAX_PATHNAME_LEN - 1);
	160	if (!buf)
	161	return NULL;
	162	if (tomoyo_realpath_from_path2(path, buf,
	163	TOMOYO_MAX_PATHNAME_LEN - 1) == 0)
	164	return buf;
8e2d39a1	165	kfree(buf);
c73bd6d4 KT	166	return NULL;
	167	}
	168
	169	/**
	170	* tomoyo_realpath - Get realpath of a pathname.
	171	*
	172	* @pathname: The pathname to solve.
	173	*
	174	* Returns the realpath of @pathname on success, NULL otherwise.
	175	*/
	176	char tomoyo_realpath(const char pathname)
	177	{
e24977d4	178	struct path path;
c73bd6d4	179
e24977d4 AV	180	if (pathname && kern_path(pathname, LOOKUP_FOLLOW, &path) == 0) {
	181	char *buf = tomoyo_realpath_from_path(&path);
	182	path_put(&path);
c73bd6d4 KT	183	return buf;
	184	}
	185	return NULL;
	186	}
	187
	188	/**
	189	* tomoyo_realpath_nofollow - Get realpath of a pathname.
	190	*
	191	* @pathname: The pathname to solve.
	192	*
	193	* Returns the realpath of @pathname on success, NULL otherwise.
	194	*/
	195	char tomoyo_realpath_nofollow(const char pathname)
	196	{
e24977d4	197	struct path path;
c73bd6d4	198
e24977d4 AV	199	if (pathname && kern_path(pathname, 0, &path) == 0) {
	200	char *buf = tomoyo_realpath_from_path(&path);
	201	path_put(&path);
c73bd6d4 KT	202	return buf;
	203	}
	204	return NULL;
	205	}
	206
	207	/* Memory allocated for non-string data. */
	208	static unsigned int tomoyo_allocated_memory_for_elements;
	209	/* Quota for holding non-string data. */
	210	static unsigned int tomoyo_quota_for_elements;
	211
	212	/**
cd7bec6a	213	* tomoyo_memory_ok - Check memory quota.
c73bd6d4	214	*
cd7bec6a	215	* @ptr: Pointer to allocated memory.
c73bd6d4	216	*
cd7bec6a	217	* Returns true on success, false otherwise.
c73bd6d4	218	*
cd7bec6a TH	219	* Caller holds tomoyo_policy_lock.
cd7bec6a TH	220	* Memory pointed by @ptr will be zeroed on success.
c73bd6d4	221	*/
cd7bec6a	222	bool tomoyo_memory_ok(void *ptr)
c73bd6d4	223	{
cd7bec6a TH	224	int allocated_len = ptr ? ksize(ptr) : 0;
	225	bool result = false;
	226	if (!ptr \|\| (tomoyo_quota_for_elements &&
	227	tomoyo_allocated_memory_for_elements
	228	+ allocated_len > tomoyo_quota_for_elements)) {
	229	printk(KERN_WARNING "ERROR: Out of memory "
	230	"for tomoyo_alloc_element().\n");
	231	if (!tomoyo_policy_loaded)
	232	panic("MAC Initialization failed.\n");
	233	} else {
	234	result = true;
	235	tomoyo_allocated_memory_for_elements += allocated_len;
	236	memset(ptr, 0, allocated_len);
c73bd6d4	237	}
cd7bec6a	238	return result;
c73bd6d4 KT	239	}
	240
	241	/* Memory allocated for string data in bytes. */
	242	static unsigned int tomoyo_allocated_memory_for_savename;
	243	/* Quota for holding string data in bytes. */
	244	static unsigned int tomoyo_quota_for_savename;
	245
c73bd6d4	246	/*
c3fa109a TH	247	* tomoyo_name_list is used for holding string data used by TOMOYO.
	248	* Since same string data is likely used for multiple times (e.g.
	249	* "/lib/libc-2.5.so"), TOMOYO shares string data in the form of
	250	* "const struct tomoyo_path_info *".
c73bd6d4 KT	251	*/
	252	static struct list_head tomoyo_name_list[TOMOYO_MAX_HASH];
	253
	254	/**
bf24fb01	255	* tomoyo_get_name - Allocate permanent memory for string data.
c73bd6d4 KT	256	*
	257	* @name: The string to store into the permernent memory.
	258	*
	259	* Returns pointer to "struct tomoyo_path_info" on success, NULL otherwise.
c73bd6d4	260	*/
bf24fb01	261	const struct tomoyo_path_info tomoyo_get_name(const char name)
c73bd6d4	262	{
c73bd6d4 KT	263	static DEFINE_MUTEX(lock);
	264	struct tomoyo_name_entry *ptr;
	265	unsigned int hash;
c73bd6d4	266	int len;
e41035a9	267	int allocated_len;
024e1a49	268	struct list_head *head;
c73bd6d4 KT	269
	270	if (!name)
	271	return NULL;
	272	len = strlen(name) + 1;
c73bd6d4	273	hash = full_name_hash((const unsigned char *) name, len - 1);
024e1a49	274	head = &tomoyo_name_list[hash_long(hash, TOMOYO_HASH_BITS)];
c73bd6d4	275	mutex_lock(&lock);
024e1a49	276	list_for_each_entry(ptr, head, list) {
bf24fb01 TH	277	if (hash != ptr->entry.hash \|\| strcmp(name, ptr->entry.name))
	278	continue;
	279	atomic_inc(&ptr->users);
	280	goto out;
c73bd6d4	281	}
e41035a9 TH	282	ptr = kzalloc(sizeof(*ptr) + len, GFP_KERNEL);
	283	allocated_len = ptr ? ksize(ptr) : 0;
	284	if (!ptr \|\| (tomoyo_quota_for_savename &&
	285	tomoyo_allocated_memory_for_savename + allocated_len
	286	> tomoyo_quota_for_savename)) {
	287	kfree(ptr);
c73bd6d4	288	printk(KERN_WARNING "ERROR: Out of memory "
bf24fb01	289	"for tomoyo_get_name().\n");
c73bd6d4 KT	290	if (!tomoyo_policy_loaded)
	291	panic("MAC Initialization failed.\n");
	292	ptr = NULL;
	293	goto out;
	294	}
e41035a9 TH	295	tomoyo_allocated_memory_for_savename += allocated_len;
	296	ptr->entry.name = ((char ) ptr) + sizeof(ptr);
	297	memmove((char *) ptr->entry.name, name, len);
bf24fb01	298	atomic_set(&ptr->users, 1);
c73bd6d4	299	tomoyo_fill_path_info(&ptr->entry);
024e1a49	300	list_add_tail(&ptr->list, head);
c73bd6d4 KT	301	out:
c73bd6d4 KT	302	mutex_unlock(&lock);
c73bd6d4 KT	303	return ptr ? &ptr->entry : NULL;
	304	}
	305
	306	/**
	307	* tomoyo_realpath_init - Initialize realpath related code.
c73bd6d4	308	*/
1581e7dd	309	void __init tomoyo_realpath_init(void)
c73bd6d4 KT	310	{
	311	int i;
	312
	313	BUILD_BUG_ON(TOMOYO_MAX_PATHNAME_LEN > PATH_MAX);
	314	for (i = 0; i < TOMOYO_MAX_HASH; i++)
	315	INIT_LIST_HEAD(&tomoyo_name_list[i]);
	316	INIT_LIST_HEAD(&tomoyo_kernel_domain.acl_info_list);
bf24fb01	317	tomoyo_kernel_domain.domainname = tomoyo_get_name(TOMOYO_ROOT_NAME);
fdb8ebb7 TH	318	/*
	319	* tomoyo_read_lock() is not needed because this function is
	320	* called before the first "delete" request.
	321	*/
	322	list_add_tail_rcu(&tomoyo_kernel_domain.list, &tomoyo_domain_list);
c73bd6d4 KT	323	if (tomoyo_find_domain(TOMOYO_ROOT_NAME) != &tomoyo_kernel_domain)
c73bd6d4 KT	324	panic("Can't register tomoyo_kernel_domain");
c73bd6d4 KT	325	}
c73bd6d4 KT	326
c73bd6d4 KT	327	/**
	328	* tomoyo_read_memory_counter - Check for memory usage in bytes.
	329	*
	330	* @head: Pointer to "struct tomoyo_io_buffer".
	331	*
	332	* Returns memory usage.
	333	*/
	334	int tomoyo_read_memory_counter(struct tomoyo_io_buffer *head)
	335	{
	336	if (!head->read_eof) {
	337	const unsigned int shared
	338	= tomoyo_allocated_memory_for_savename;
	339	const unsigned int private
	340	= tomoyo_allocated_memory_for_elements;
c73bd6d4 KT	341	char buffer[64];
	342
	343	memset(buffer, 0, sizeof(buffer));
	344	if (tomoyo_quota_for_savename)
	345	snprintf(buffer, sizeof(buffer) - 1,
	346	" (Quota: %10u)",
	347	tomoyo_quota_for_savename);
	348	else
	349	buffer[0] = '\0';
	350	tomoyo_io_printf(head, "Shared: %10u%s\n", shared, buffer);
	351	if (tomoyo_quota_for_elements)
	352	snprintf(buffer, sizeof(buffer) - 1,
	353	" (Quota: %10u)",
	354	tomoyo_quota_for_elements);
	355	else
	356	buffer[0] = '\0';
	357	tomoyo_io_printf(head, "Private: %10u%s\n", private, buffer);
8e2d39a1	358	tomoyo_io_printf(head, "Total: %10u\n", shared + private);
c73bd6d4 KT	359	head->read_eof = true;
	360	}
	361	return 0;
	362	}
	363
	364	/**
	365	* tomoyo_write_memory_quota - Set memory quota.
	366	*
	367	* @head: Pointer to "struct tomoyo_io_buffer".
	368	*
	369	* Returns 0.
	370	*/
	371	int tomoyo_write_memory_quota(struct tomoyo_io_buffer *head)
	372	{
	373	char *data = head->write_buf;
	374	unsigned int size;
	375
	376	if (sscanf(data, "Shared: %u", &size) == 1)
	377	tomoyo_quota_for_savename = size;
	378	else if (sscanf(data, "Private: %u", &size) == 1)
	379	tomoyo_quota_for_elements = size;
	380	return 0;
	381	}