1 // SPDX-License-Identifier: GPL-2.0
17 #include <linux/bpf-cgroup.h>
39 	return head->ctl_table[0].child == sysctl_mount_point;  in is_empty_dir()
44 	dir->header.ctl_table[0].child = sysctl_mount_point;  in set_empty_dir()
50 	dir->header.ctl_table[0].child = NULL;  in clear_empty_dir()
58 	atomic_inc(&poll->event);  in proc_sys_poll_notify()
59 	wake_up_interruptible(&poll->wait);  in proc_sys_poll_notify()
90 	if (dir->header.parent)  in sysctl_print_dir()
91 		sysctl_print_dir(dir->header.parent);  in sysctl_print_dir()
92 	pr_cont("%s/", dir->header.ctl_table[0].procname);  in sysctl_print_dir()
101 		cmp = len1 - len2;  in namecmp()
107 	struct ctl_dir *dir, const char *name, int namelen)  in find_entry()  argument
110 	struct ctl_table *entry;  in find_entry()  local
111 	struct rb_node *node = dir->root.rb_node;  in find_entry()
120 		head = ctl_node->header;  in find_entry()
121 		entry = &head->ctl_table[ctl_node - head->node];  in find_entry()
122 		procname = entry->procname;  in find_entry()
124 		cmp = namecmp(name, namelen, procname, strlen(procname));  in find_entry()
126 			node = node->rb_left;  in find_entry()
128 			node = node->rb_right;  in find_entry()
131 			return entry;  in find_entry()
137 static int insert_entry(struct ctl_table_header *head, struct ctl_table *entry)  in insert_entry()  argument
139 	struct rb_node *node = &head->node[entry - head->ctl_table].node;  in insert_entry()
140 	struct rb_node **p = &head->parent->root.rb_node;  in insert_entry()
142 	const char *name = entry->procname;  in insert_entry()  local
143 	int namelen = strlen(name);  in insert_entry()
154 		parent_head = parent_node->header;  in insert_entry()
155 		parent_entry = &parent_head->ctl_table[parent_node - parent_head->node];  in insert_entry()
156 		parent_name = parent_entry->procname;  in insert_entry()
158 		cmp = namecmp(name, namelen, parent_name, strlen(parent_name));  in insert_entry()
160 			p = &(*p)->rb_left;  in insert_entry()
162 			p = &(*p)->rb_right;  in insert_entry()
164 			pr_err("sysctl duplicate entry: ");  in insert_entry()
165 			sysctl_print_dir(head->parent);  in insert_entry()
166 			pr_cont("/%s\n", entry->procname);  in insert_entry()
167 			return -EEXIST;  in insert_entry()
172 	rb_insert_color(node, &head->parent->root);  in insert_entry()
176 static void erase_entry(struct ctl_table_header *head, struct ctl_table *entry)  in erase_entry()  argument
178 	struct rb_node *node = &head->node[entry - head->ctl_table].node;  in erase_entry()
180 	rb_erase(node, &head->parent->root);  in erase_entry()
187 	head->ctl_table = table;  in init_header()
188 	head->ctl_table_arg = table;  in init_header()
189 	head->used = 0;  in init_header()
190 	head->count = 1;  in init_header()
191 	head->nreg = 1;  in init_header()
192 	head->unregistering = NULL;  in init_header()
193 	head->root = root;  in init_header()
194 	head->set = set;  in init_header()
195 	head->parent = NULL;  in init_header()
196 	head->node = node;  in init_header()
197 	INIT_HLIST_HEAD(&head->inodes);  in init_header()
199 		struct ctl_table *entry;  in init_header()  local
200 		for (entry = table; entry->procname; entry++, node++)  in init_header()
201 			node->header = head;  in init_header()
207 	struct ctl_table *entry;  in erase_header()  local
208 	for (entry = head->ctl_table; entry->procname; entry++)  in erase_header()
209 		erase_entry(head, entry);  in erase_header()
214 	struct ctl_table *entry;  in insert_header()  local
218 	if (is_empty_dir(&dir->header))  in insert_header()
219 		return -EROFS;  in insert_header()
222 	if (header->ctl_table == sysctl_mount_point) {  in insert_header()
223 		if (!RB_EMPTY_ROOT(&dir->root))  in insert_header()
224 			return -EINVAL;  in insert_header()
228 	dir->header.nreg++;  in insert_header()
229 	header->parent = dir;  in insert_header()
233 	for (entry = header->ctl_table; entry->procname; entry++) {  in insert_header()
234 		err = insert_entry(header, entry);  in insert_header()
243 	if (header->ctl_table == sysctl_mount_point)  in insert_header()
245 	header->parent = NULL;  in insert_header()
246 	drop_sysctl_table(&dir->header);  in insert_header()
253 	if (unlikely(p->unregistering))  in use_table()
255 	p->used++;  in use_table()
262 	if (!--p->used)  in unuse_table()
263 		if (unlikely(p->unregistering))  in unuse_table()
264 			complete(p->unregistering);  in unuse_table()
269 	proc_invalidate_siblings_dcache(&head->inodes, &sysctl_lock);  in proc_sys_invalidate_dcache()
276 	 * if p->used is 0, nobody will ever touch that entry again;  in start_unregistering()
279 	if (unlikely(p->used)) {  in start_unregistering()
282 		p->unregistering = &wait;  in start_unregistering()
286 		/* anything non-NULL; we'll never dereference it */  in start_unregistering()
287 		p->unregistering = ERR_PTR(-EINVAL);  in start_unregistering()
308 		head = ERR_PTR(-ENOENT);  in sysctl_head_grab()
325 	struct ctl_table_set *set = &root->default_set;  in lookup_header_set()
326 	if (root->lookup)  in lookup_header_set()
327 		set = root->lookup(root);  in lookup_header_set()
333 				      const char *name, int namelen)  in lookup_entry()  argument
336 	struct ctl_table *entry;  in lookup_entry()  local
339 	entry = find_entry(&head, dir, name, namelen);  in lookup_entry()
340 	if (entry && use_table(head))  in lookup_entry()
343 		entry = NULL;  in lookup_entry()
345 	return entry;  in lookup_entry()
354 		if (use_table(ctl_node->header))  in first_usable_entry()
364 	struct ctl_table *entry = NULL;  in first_entry()  local
368 	ctl_node = first_usable_entry(rb_first(&dir->root));  in first_entry()
371 		head = ctl_node->header;  in first_entry()
372 		entry = &head->ctl_table[ctl_node - head->node];  in first_entry()
375 	*pentry = entry;  in first_entry()
381 	struct ctl_table *entry = *pentry;  in next_entry()  local
382 	struct ctl_node *ctl_node = &head->node[entry - head->ctl_table];  in next_entry()
387 	ctl_node = first_usable_entry(rb_next(&ctl_node->node));  in next_entry()
391 		head = ctl_node->header;  in next_entry()
392 		entry = &head->ctl_table[ctl_node - head->node];  in next_entry()
395 	*pentry = entry;  in next_entry()
411 	return -EACCES;  in test_perm()
416 	struct ctl_table_root *root = head->root;  in sysctl_perm()
419 	if (root->permissions)  in sysctl_perm()
420 		mode = root->permissions(head, table);  in sysctl_perm()
422 		mode = table->mode;  in sysctl_perm()
430 	struct ctl_table_root *root = head->root;  in proc_sys_make_inode()
436 		return ERR_PTR(-ENOMEM);  in proc_sys_make_inode()
438 	inode->i_ino = get_next_ino();  in proc_sys_make_inode()
443 	if (unlikely(head->unregistering)) {  in proc_sys_make_inode()
446 		return ERR_PTR(-ENOENT);  in proc_sys_make_inode()
448 	ei->sysctl = head;  in proc_sys_make_inode()
449 	ei->sysctl_entry = table;  in proc_sys_make_inode()
450 	hlist_add_head_rcu(&ei->sibling_inodes, &head->inodes);  in proc_sys_make_inode()
451 	head->count++;  in proc_sys_make_inode()
454 	inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);  in proc_sys_make_inode()
455 	inode->i_mode = table->mode;  in proc_sys_make_inode()
456 	if (!S_ISDIR(table->mode)) {  in proc_sys_make_inode()
457 		inode->i_mode |= S_IFREG;  in proc_sys_make_inode()
458 		inode->i_op = &proc_sys_inode_operations;  in proc_sys_make_inode()
459 		inode->i_fop = &proc_sys_file_operations;  in proc_sys_make_inode()
461 		inode->i_mode |= S_IFDIR;  in proc_sys_make_inode()
462 		inode->i_op = &proc_sys_dir_operations;  in proc_sys_make_inode()
463 		inode->i_fop = &proc_sys_dir_file_operations;  in proc_sys_make_inode()
468 	if (root->set_ownership)  in proc_sys_make_inode()
469 		root->set_ownership(head, table, &inode->i_uid, &inode->i_gid);  in proc_sys_make_inode()
471 		inode->i_uid = GLOBAL_ROOT_UID;  in proc_sys_make_inode()
472 		inode->i_gid = GLOBAL_ROOT_GID;  in proc_sys_make_inode()
481 	hlist_del_init_rcu(&PROC_I(inode)->sibling_inodes);  in proc_sys_evict_inode()
482 	if (!--head->count)  in proc_sys_evict_inode()
489 	struct ctl_table_header *head = PROC_I(inode)->sysctl;  in grab_header()
500 	const struct qstr *name = &dentry->d_name;  in proc_sys_lookup()  local
503 	struct dentry *err = ERR_PTR(-ENOENT);  in proc_sys_lookup()
512 	p = lookup_entry(&h, ctl_dir, name->name, name->len);  in proc_sys_lookup()
516 	if (S_ISLNK(p->mode)) {  in proc_sys_lookup()
523 	inode = proc_sys_make_inode(dir->i_sb, h ? h : head, p);  in proc_sys_lookup()
542 	struct inode *inode = file_inode(iocb->ki_filp);  in proc_sys_call_handler()
544 	struct ctl_table *table = PROC_I(inode)->sysctl_entry;  in proc_sys_call_handler()
556 	error = -EPERM;  in proc_sys_call_handler()
560 	/* if that can happen at all, it should be -EINVAL, not -EISDIR */  in proc_sys_call_handler()
561 	error = -EINVAL;  in proc_sys_call_handler()
562 	if (!table->proc_handler)  in proc_sys_call_handler()
566 	error = -ENOMEM;  in proc_sys_call_handler()
574 		error = -EFAULT;  in proc_sys_call_handler()
581 					   &iocb->ki_pos);  in proc_sys_call_handler()
586 	error = table->proc_handler(table, write, kbuf, &count, &iocb->ki_pos);  in proc_sys_call_handler()
591 		error = -EFAULT;  in proc_sys_call_handler()
618 	struct ctl_table *table = PROC_I(inode)->sysctl_entry;  in proc_sys_open()
624 	if (table->poll)  in proc_sys_open()
625 		filp->private_data = proc_sys_poll_event(table->poll);  in proc_sys_open()
636 	struct ctl_table *table = PROC_I(inode)->sysctl_entry;  in proc_sys_poll()
644 	if (!table->proc_handler)  in proc_sys_poll()
647 	if (!table->poll)  in proc_sys_poll()
650 	event = (unsigned long)filp->private_data;  in proc_sys_poll()
651 	poll_wait(filp, &table->poll->wait, wait);  in proc_sys_poll()
653 	if (event != atomic_read(&table->poll->event)) {  in proc_sys_poll()
654 		filp->private_data = proc_sys_poll_event(table->poll);  in proc_sys_poll()
669 	struct dentry *child, *dir = file->f_path.dentry;  in proc_sys_fill_cache()
675 	qname.name = table->procname;  in proc_sys_fill_cache()
676 	qname.len  = strlen(table->procname);  in proc_sys_fill_cache()
677 	qname.hash = full_name_hash(dir, qname.name, qname.len);  in proc_sys_fill_cache()
687 			inode = proc_sys_make_inode(dir->d_sb, head, table);  in proc_sys_fill_cache()
707 	ino  = inode->i_ino;  in proc_sys_fill_cache()
708 	type = inode->i_mode >> 12;  in proc_sys_fill_cache()
710 	return dir_emit(ctx, qname.name, qname.len, ino, type);  in proc_sys_fill_cache()
740 	if ((*pos)++ < ctx->pos)  in scan()
743 	if (unlikely(S_ISLNK(table->mode)))  in scan()
749 		ctx->pos = *pos;  in scan()
758 	struct ctl_table *entry;  in proc_sys_readdir()  local
772 	for (first_entry(ctl_dir, &h, &entry); h; next_entry(&h, &entry)) {  in proc_sys_readdir()
773 		if (!scan(h, entry, &pos, file, ctx)) {  in proc_sys_readdir()
795 	if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode))  in proc_sys_permission()
796 		return -EACCES;  in proc_sys_permission()
802 	table = PROC_I(inode)->sysctl_entry;  in proc_sys_permission()
803 	if (!table) /* global root - r-xr-xr-x */  in proc_sys_permission()
804 		error = mask & MAY_WRITE ? -EACCES : 0;  in proc_sys_permission()
805 	else /* Use the permissions on the sysctl table entry */  in proc_sys_permission()
818 	if (attr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID))  in proc_sys_setattr()
819 		return -EPERM;  in proc_sys_setattr()
834 	struct inode *inode = d_inode(path->dentry);  in proc_sys_getattr()
836 	struct ctl_table *table = PROC_I(inode)->sysctl_entry;  in proc_sys_getattr()
843 		stat->mode = (stat->mode & S_IFMT) | table->mode;  in proc_sys_getattr()
881 		return -ECHILD;  in proc_sys_revalidate()
882 	return !PROC_I(d_inode(dentry))->sysctl->unregistering;  in proc_sys_revalidate()
887 	return !!PROC_I(d_inode(dentry))->sysctl->unregistering;  in proc_sys_delete()
892 	struct ctl_table_set *set = p->set;  in sysctl_is_seen()
895 	if (p->unregistering)  in sysctl_is_seen()
897 	else if (!set->is_seen)  in sysctl_is_seen()
900 		res = set->is_seen(set);  in sysctl_is_seen()
906 		unsigned int len, const char *str, const struct qstr *name)  in proc_sys_compare()  argument
911 	/* Although proc doesn't have negative dentries, rcu-walk means  in proc_sys_compare()
917 	if (name->len != len)  in proc_sys_compare()
919 	if (memcmp(name->name, str, len))  in proc_sys_compare()
921 	head = rcu_dereference(PROC_I(inode)->sysctl);  in proc_sys_compare()
932 				   const char *name, int namelen)  in find_subdir()  argument
935 	struct ctl_table *entry;  in find_subdir()  local
937 	entry = find_entry(&head, dir, name, namelen);  in find_subdir()
938 	if (!entry)  in find_subdir()
939 		return ERR_PTR(-ENOENT);  in find_subdir()
940 	if (!S_ISDIR(entry->mode))  in find_subdir()
941 		return ERR_PTR(-ENOTDIR);  in find_subdir()
946 			       const char *name, int namelen)  in new_dir()  argument
962 	memcpy(new_name, name, namelen);  in new_dir()
966 	init_header(&new->header, set->dir.header.root, set, node, table);  in new_dir()
972  * get_subdir - find or create a subdir with the specified name.
974  * @name: The name of the subdirectory to find or create
975  * @namelen: The length of name
984 				  const char *name, int namelen)  in get_subdir()  argument
986 	struct ctl_table_set *set = dir->header.set;  in get_subdir()
991 	subdir = find_subdir(dir, name, namelen);  in get_subdir()
994 	if (PTR_ERR(subdir) != -ENOENT)  in get_subdir()
998 	new = new_dir(set, name, namelen);  in get_subdir()
1000 	subdir = ERR_PTR(-ENOMEM);  in get_subdir()
1005 	subdir = find_subdir(dir, name, namelen);  in get_subdir()
1008 	if (PTR_ERR(subdir) != -ENOENT)  in get_subdir()
1011 	/* Nope.  Use the our freshly made directory entry. */  in get_subdir()
1012 	err = insert_header(dir, &new->header);  in get_subdir()
1018 	subdir->header.nreg++;  in get_subdir()
1024 			namelen, namelen, name, PTR_ERR(subdir));  in get_subdir()
1026 	drop_sysctl_table(&dir->header);  in get_subdir()
1028 		drop_sysctl_table(&new->header);  in get_subdir()
1037 	if (!dir->header.parent)  in xlate_dir()
1038 		return &set->dir;  in xlate_dir()
1039 	parent = xlate_dir(set, dir->header.parent);  in xlate_dir()
1042 	procname = dir->header.ctl_table[0].procname;  in xlate_dir()
1052 	struct ctl_table *entry;  in sysctl_follow_link()  local
1058 	root = (*pentry)->data;  in sysctl_follow_link()
1060 	dir = xlate_dir(set, (*phead)->parent);  in sysctl_follow_link()
1064 		const char *procname = (*pentry)->procname;  in sysctl_follow_link()
1066 		entry = find_entry(&head, dir, procname, strlen(procname));  in sysctl_follow_link()
1067 		ret = -ENOENT;  in sysctl_follow_link()
1068 		if (entry && use_table(head)) {  in sysctl_follow_link()
1071 			*pentry = entry;  in sysctl_follow_link()
1090 	       path, table->procname, &vaf);  in sysctl_err()
1093 	return -EINVAL;  in sysctl_err()
1100 	if ((table->proc_handler == proc_douintvec) ||  in sysctl_check_table_array()
1101 	    (table->proc_handler == proc_douintvec_minmax)) {  in sysctl_check_table_array()
1102 		if (table->maxlen != sizeof(unsigned int))  in sysctl_check_table_array()
1106 	if (table->proc_handler == proc_dou8vec_minmax) {  in sysctl_check_table_array()
1107 		if (table->maxlen != sizeof(u8))  in sysctl_check_table_array()
1117 	for (; table->procname; table++) {  in sysctl_check_table()
1118 		if (table->child)  in sysctl_check_table()
1121 		if ((table->proc_handler == proc_dostring) ||  in sysctl_check_table()
1122 		    (table->proc_handler == proc_dointvec) ||  in sysctl_check_table()
1123 		    (table->proc_handler == proc_douintvec) ||  in sysctl_check_table()
1124 		    (table->proc_handler == proc_douintvec_minmax) ||  in sysctl_check_table()
1125 		    (table->proc_handler == proc_dointvec_minmax) ||  in sysctl_check_table()
1126 		    (table->proc_handler == proc_dou8vec_minmax) ||  in sysctl_check_table()
1127 		    (table->proc_handler == proc_dointvec_jiffies) ||  in sysctl_check_table()
1128 		    (table->proc_handler == proc_dointvec_userhz_jiffies) ||  in sysctl_check_table()
1129 		    (table->proc_handler == proc_dointvec_ms_jiffies) ||  in sysctl_check_table()
1130 		    (table->proc_handler == proc_doulongvec_minmax) ||  in sysctl_check_table()
1131 		    (table->proc_handler == proc_doulongvec_ms_jiffies_minmax)) {  in sysctl_check_table()
1132 			if (!table->data)  in sysctl_check_table()
1134 			if (!table->maxlen)  in sysctl_check_table()
1139 		if (!table->proc_handler)  in sysctl_check_table()
1142 		if ((table->mode & (S_IRUGO|S_IWUGO)) != table->mode)  in sysctl_check_table()
1144 				table->mode);  in sysctl_check_table()
1152 	struct ctl_table *link_table, *entry, *link;  in new_links()  local
1160 	for (entry = table; entry->procname; entry++) {  in new_links()
1162 		name_bytes += strlen(entry->procname) + 1;  in new_links()
1178 	for (link = link_table, entry = table; entry->procname; link++, entry++) {  in new_links()
1179 		int len = strlen(entry->procname) + 1;  in new_links()
1180 		memcpy(link_name, entry->procname, len);  in new_links()
1181 		link->procname = link_name;  in new_links()
1182 		link->mode = S_IFLNK|S_IRWXUGO;  in new_links()
1183 		link->data = link_root;  in new_links()
1186 	init_header(links, dir->header.root, dir->header.set, node, link_table);  in new_links()
1187 	links->nreg = nr_entries;  in new_links()
1196 	struct ctl_table *entry, *link;  in get_links()  local
1198 	/* Are there links available for every entry in table? */  in get_links()
1199 	for (entry = table; entry->procname; entry++) {  in get_links()
1200 		const char *procname = entry->procname;  in get_links()
1204 		if (S_ISDIR(link->mode) && S_ISDIR(entry->mode))  in get_links()
1206 		if (S_ISLNK(link->mode) && (link->data == link_root))  in get_links()
1212 	for (entry = table; entry->procname; entry++) {  in get_links()
1213 		const char *procname = entry->procname;  in get_links()
1215 		head->nreg++;  in get_links()
1227 	if (head->set == root_set)  in insert_links()
1230 	core_parent = xlate_dir(root_set, head->parent);  in insert_links()
1234 	if (get_links(core_parent, head->ctl_table, head->root))  in insert_links()
1237 	core_parent->header.nreg++;  in insert_links()
1240 	links = new_links(core_parent, head->ctl_table, head->root);  in insert_links()
1243 	err = -ENOMEM;  in insert_links()
1248 	if (get_links(core_parent, head->ctl_table, head->root)) {  in insert_links()
1257 	drop_sysctl_table(&core_parent->header);  in insert_links()
1262  * __register_sysctl_table - register a leaf sysctl table
1265  * @table: the top-level table structure
1268  * array. A completely 0 filled entry terminates the table.
1272  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1275  * data - a pointer to data for use by proc_handler
1277  * maxlen - the maximum size in bytes of the data
1279  * mode - the file permissions for the /proc/sys file
1281  * child - must be %NULL.
1283  * proc_handler - the text handler routine (described below)
1285  * extra1, extra2 - extra pointers usable by the proc handler routines
1288  * under /proc; non-leaf nodes will be represented by directories.
1291  * Several default handlers are available to cover common cases -
1307 	struct ctl_table_root *root = set->dir.header.root;  in __register_sysctl_table()
1309 	const char *name, *nextname;  in __register_sysctl_table()  local
1311 	struct ctl_table *entry;  in __register_sysctl_table()  local
1315 	for (entry = table; entry->procname; entry++)  in __register_sysctl_table()
1329 	dir = &set->dir;  in __register_sysctl_table()
1331 	dir->header.nreg++;  in __register_sysctl_table()
1335 	for (name = path; name; name = nextname) {  in __register_sysctl_table()
1337 		nextname = strchr(name, '/');  in __register_sysctl_table()
1339 			namelen = nextname - name;  in __register_sysctl_table()
1342 			namelen = strlen(name);  in __register_sysctl_table()
1347 		dir = get_subdir(dir, name, namelen);  in __register_sysctl_table()
1356 	drop_sysctl_table(&dir->header);  in __register_sysctl_table()
1362 	drop_sysctl_table(&dir->header);  in __register_sysctl_table()
1371  * register_sysctl - register a sysctl table
1376  * array. A completely 0 filled entry terminates the table.
1387 static char *append_path(const char *path, char *pos, const char *name)  in append_path()  argument
1390 	namelen = strlen(name);  in append_path()
1391 	if (((pos - path) + namelen + 2) >= PATH_MAX)  in append_path()
1393 	memcpy(pos, name, namelen);  in append_path()
1404 	struct ctl_table *entry;  in count_subheaders()  local
1407 	if (!table || !table->procname)  in count_subheaders()
1410 	for (entry = table; entry->procname; entry++) {  in count_subheaders()
1411 		if (entry->child)  in count_subheaders()
1412 			nr_subheaders += count_subheaders(entry->child);  in count_subheaders()
1424 	struct ctl_table *entry, *files;  in register_leaf_sysctl_tables()  local
1427 	int err = -ENOMEM;  in register_leaf_sysctl_tables()
1429 	for (entry = table; entry->procname; entry++) {  in register_leaf_sysctl_tables()
1430 		if (entry->child)  in register_leaf_sysctl_tables()
1446 		for (new = files, entry = table; entry->procname; entry++) {  in register_leaf_sysctl_tables()
1447 			if (entry->child)  in register_leaf_sysctl_tables()
1449 			*new = *entry;  in register_leaf_sysctl_tables()
1464 		header->ctl_table_arg = ctl_table_arg;  in register_leaf_sysctl_tables()
1470 	for (entry = table; entry->procname; entry++) {  in register_leaf_sysctl_tables()
1473 		if (!entry->child)  in register_leaf_sysctl_tables()
1476 		err = -ENAMETOOLONG;  in register_leaf_sysctl_tables()
1477 		child_pos = append_path(path, pos, entry->procname);  in register_leaf_sysctl_tables()
1482 						  set, entry->child);  in register_leaf_sysctl_tables()
1494  * __register_sysctl_paths - register a sysctl table hierarchy
1497  * @table: the top-level table structure
1500  * array. A completely 0 filled entry terminates the table.
1519 	for (component = path; component->procname; component++) {  in __register_sysctl_paths()
1520 		pos = append_path(new_path, pos, component->procname);  in __register_sysctl_paths()
1524 	while (table->procname && table->child && !table[1].procname) {  in __register_sysctl_paths()
1525 		pos = append_path(new_path, pos, table->procname);  in __register_sysctl_paths()
1528 		table = table->child;  in __register_sysctl_paths()
1533 			header->ctl_table_arg = ctl_table_arg;  in __register_sysctl_paths()
1542 		header->ctl_table_arg = ctl_table_arg;  in __register_sysctl_paths()
1555 		struct ctl_table_header *subh = *(--subheader);  in __register_sysctl_paths()
1556 		struct ctl_table *table = subh->ctl_table_arg;  in __register_sysctl_paths()
1566  * register_sysctl_paths - register a sysctl table hierarchy
1568  * @table: the top-level table structure
1571  * array. A completely 0 filled entry terminates the table.
1584  * register_sysctl_table - register a sysctl table hierarchy
1585  * @table: the top-level table structure
1588  * array. A completely 0 filled entry terminates the table.
1603 	struct ctl_table_root *root = header->root;  in put_links()
1604 	struct ctl_dir *parent = header->parent;  in put_links()
1606 	struct ctl_table *entry;  in put_links()  local
1608 	if (header->set == root_set)  in put_links()
1615 	for (entry = header->ctl_table; entry->procname; entry++) {  in put_links()
1618 		const char *name = entry->procname;  in put_links()  local
1620 		link = find_entry(&link_head, core_parent, name, strlen(name));  in put_links()
1622 		    ((S_ISDIR(link->mode) && S_ISDIR(entry->mode)) ||  in put_links()
1623 		     (S_ISLNK(link->mode) && (link->data == root)))) {  in put_links()
1629 			pr_cont("/%s\n", name);  in put_links()
1636 	struct ctl_dir *parent = header->parent;  in drop_sysctl_table()
1638 	if (--header->nreg)  in drop_sysctl_table()
1646 	if (!--header->count)  in drop_sysctl_table()
1650 		drop_sysctl_table(&parent->header);  in drop_sysctl_table()
1654  * unregister_sysctl_table - unregister a sysctl table hierarchy
1668 	nr_subheaders = count_subheaders(header->ctl_table_arg);  in unregister_sysctl_table()
1674 		for (i = nr_subheaders -1; i >= 0; i--) {  in unregister_sysctl_table()
1676 			struct ctl_table *table = subh->ctl_table_arg;  in unregister_sysctl_table()
1695 	set->is_seen = is_seen;  in setup_sysctl_set()
1696 	init_header(&set->dir.header, root, set, NULL, root_table);  in setup_sysctl_set()
1701 	WARN_ON(!RB_EMPTY_ROOT(&set->dir.root));  in retire_sysctl_set()
1709 	proc_sys_root->proc_iops = &proc_sys_dir_operations;  in proc_sys_init()
1710 	proc_sys_root->proc_dir_ops = &proc_sys_dir_file_operations;  in proc_sys_init()
1711 	proc_sys_root->nlink = 0;  in proc_sys_init()
1724  * place and only keep the historical name for compatibility. This is not meant
1743 	for (alias = &sysctl_aliases[0]; alias->kernel_param != NULL; alias++) {  in sysctl_find_alias()
1744 		if (strcmp(alias->kernel_param, param) == 0)  in sysctl_find_alias()
1745 			return alias->sysctl_param;  in sysctl_find_alias()
1764 	if (strncmp(param, "sysctl", sizeof("sysctl") - 1) == 0) {  in process_sysctl_arg()
1765 		param += sizeof("sysctl") - 1;  in process_sysctl_arg()
1778 		return -EINVAL;  in process_sysctl_arg()
1781 		return -EINVAL;  in process_sysctl_arg()
1813 		if (err == -ENOENT)  in process_sysctl_arg()
1816 		else if (err == -EACCES)  in process_sysctl_arg()
1817 			pr_err("Failed to set sysctl parameter '%s=%s': permission denied (read-only?)\n",  in process_sysctl_arg()
1827 		if (err == -EINVAL)  in process_sysctl_arg()
1857 		   NULL, 0, -1, -1, &proc_mnt, process_sysctl_arg);  in do_sysctl_args()