15 files changed, 351 insertions, 434 deletions

diff --git a/drivers/parport/procfs.c b/drivers/parport/procfs.c
index d740eba3c099..4e5b972c3e26 100644
--- a/drivers/parport/procfs.c
+++ b/drivers/parport/procfs.c
@@ -32,6 +32,13 @@
 #define PARPORT_MAX_TIMESLICE_VALUE ((unsigned long) HZ)
 #define PARPORT_MIN_SPINTIME_VALUE 1
 #define PARPORT_MAX_SPINTIME_VALUE 1000
+/*
+ * PARPORT_BASE_* is the size of the known parts of the sysctl path
+ * in dev/partport/%s/devices/%s. "dev/parport/"(12), "/devices/"(9
+ * and null char(1).
+ */
+#define PARPORT_BASE_PATH_SIZE 13
+#define PARPORT_BASE_DEVICES_PATH_SIZE 22
 
 static int do_active_device(struct ctl_table *table, int write,
 		      void *result, size_t *lenp, loff_t *ppos)
@@ -236,13 +243,6 @@ do {									\
 	return 0;
 }
 
-#define PARPORT_PORT_DIR(CHILD) { .procname = NULL, .mode = 0555, .child = CHILD }
-#define PARPORT_PARPORT_DIR(CHILD) { .procname = "parport", \
-                                     .mode = 0555, .child = CHILD }
-#define PARPORT_DEV_DIR(CHILD) { .procname = "dev", .mode = 0555, .child = CHILD }
-#define PARPORT_DEVICES_ROOT_DIR  {  .procname = "devices", \
-                                    .mode = 0555, .child = NULL }
-
 static const unsigned long parport_min_timeslice_value =
 PARPORT_MIN_TIMESLICE_VALUE;
 
@@ -257,17 +257,16 @@ PARPORT_MAX_SPINTIME_VALUE;
 
 
 struct parport_sysctl_table {
-	struct ctl_table_header *sysctl_header;
+	struct ctl_table_header *port_header;
+	struct ctl_table_header *devices_header;
 	struct ctl_table vars[12];
 	struct ctl_table device_dir[2];
-	struct ctl_table port_dir[2];
-	struct ctl_table parport_dir[2];
-	struct ctl_table dev_dir[2];
 };
 
 static const struct parport_sysctl_table parport_sysctl_template = {
-	.sysctl_header = NULL,
-        {
+	.port_header = NULL,
+	.devices_header = NULL,
+	{
 		{
 			.procname	= "spintime",
 			.data		= NULL,
@@ -305,7 +304,6 @@ static const struct parport_sysctl_table parport_sysctl_template = {
 			.mode		= 0444,
 			.proc_handler	= do_hardware_modes
 		},
-		PARPORT_DEVICES_ROOT_DIR,
 #ifdef CONFIG_PARPORT_1284
 		{
 			.procname	= "autoprobe",
@@ -355,18 +353,6 @@ static const struct parport_sysctl_table parport_sysctl_template = {
 		},
 		{}
 	},
-	{
-		PARPORT_PORT_DIR(NULL),
-		{}
-	},
-	{
-		PARPORT_PARPORT_DIR(NULL),
-		{}
-	},
-	{
-		PARPORT_DEV_DIR(NULL),
-		{}
-	}
 };
 
 struct parport_device_sysctl_table
@@ -393,6 +379,7 @@ parport_device_sysctl_template = {
 			.extra1		= (void*) &parport_min_timeslice_value,
 			.extra2		= (void*) &parport_max_timeslice_value
 		},
+		{}
 	},
 	{
 		{
@@ -400,25 +387,8 @@ parport_device_sysctl_template = {
 			.data		= NULL,
 			.maxlen		= 0,
 			.mode		= 0555,
-			.child		= NULL
 		},
 		{}
-	},
-	{
-		PARPORT_DEVICES_ROOT_DIR,
-		{}
-	},
-	{
-		PARPORT_PORT_DIR(NULL),
-		{}
-	},
-	{
-		PARPORT_PARPORT_DIR(NULL),
-		{}
-	},
-	{
-		PARPORT_DEV_DIR(NULL),
-		{}
 	}
 };
 
@@ -454,30 +424,15 @@ parport_default_sysctl_table = {
 			.extra2		= (void*) &parport_max_spintime_value
 		},
 		{}
-	},
-	{
-		{
-			.procname	= "default",
-			.mode		= 0555,
-			.child		= parport_default_sysctl_table.vars
-		},
-		{}
-	},
-	{
-		PARPORT_PARPORT_DIR(parport_default_sysctl_table.default_dir),
-		{}
-	},
-	{
-		PARPORT_DEV_DIR(parport_default_sysctl_table.parport_dir),
-		{}
 	}
 };
 
-
 int parport_proc_register(struct parport *port)
 {
 	struct parport_sysctl_table *t;
-	int i;
+	char *tmp_dir_path;
+	size_t tmp_path_len, port_name_len;
+	int bytes_written, i, err = 0;
 
 	t = kmemdup(&parport_sysctl_template, sizeof(*t), GFP_KERNEL);
 	if (t == NULL)
@@ -485,28 +440,64 @@ int parport_proc_register(struct parport *port)
 
 	t->device_dir[0].extra1 = port;
 
-	for (i = 0; i < 5; i++)
+	t->vars[0].data = &port->spintime;
+	for (i = 0; i < 5; i++) {
 		t->vars[i].extra1 = port;
+		t->vars[5 + i].extra2 = &port->probe_info[i];
+	}
 
-	t->vars[0].data = &port->spintime;
-	t->vars[5].child = t->device_dir;
-	
-	for (i = 0; i < 5; i++)
-		t->vars[6 + i].extra2 = &port->probe_info[i];
+	port_name_len = strnlen(port->name, PARPORT_NAME_MAX_LEN);
+	/*
+	 * Allocate a buffer for two paths: dev/parport/PORT and dev/parport/PORT/devices.
+	 * We calculate for the second as that will give us enough for the first.
+	 */
+	tmp_path_len = PARPORT_BASE_DEVICES_PATH_SIZE + port_name_len;
+	tmp_dir_path = kzalloc(tmp_path_len, GFP_KERNEL);
+	if (!tmp_dir_path) {
+		err = -ENOMEM;
+		goto exit_free_t;
+	}
 
-	t->port_dir[0].procname = port->name;
+	bytes_written = snprintf(tmp_dir_path, tmp_path_len,
+				 "dev/parport/%s/devices", port->name);
+	if (tmp_path_len <= bytes_written) {
+		err = -ENOENT;
+		goto exit_free_tmp_dir_path;
+	}
+	t->devices_header = register_sysctl(tmp_dir_path, t->device_dir);
+	if (t->devices_header == NULL) {
+		err = -ENOENT;
+		goto  exit_free_tmp_dir_path;
+	}
 
-	t->port_dir[0].child = t->vars;
-	t->parport_dir[0].child = t->port_dir;
-	t->dev_dir[0].child = t->parport_dir;
+	tmp_path_len = PARPORT_BASE_PATH_SIZE + port_name_len;
+	bytes_written = snprintf(tmp_dir_path, tmp_path_len,
+				 "dev/parport/%s", port->name);
+	if (tmp_path_len <= bytes_written) {
+		err = -ENOENT;
+		goto unregister_devices_h;
+	}
 
-	t->sysctl_header = register_sysctl_table(t->dev_dir);
-	if (t->sysctl_header == NULL) {
-		kfree(t);
-		t = NULL;
+	t->port_header = register_sysctl(tmp_dir_path, t->vars);
+	if (t->port_header == NULL) {
+		err = -ENOENT;
+		goto unregister_devices_h;
 	}
+
 	port->sysctl_table = t;
+
+	kfree(tmp_dir_path);
 	return 0;
+
+unregister_devices_h:
+	unregister_sysctl_table(t->devices_header);
+
+exit_free_tmp_dir_path:
+	kfree(tmp_dir_path);
+
+exit_free_t:
+	kfree(t);
+	return err;
 }
 
 int parport_proc_unregister(struct parport *port)
@@ -514,7 +505,8 @@ int parport_proc_unregister(struct parport *port)
 	if (port->sysctl_table) {
 		struct parport_sysctl_table *t = port->sysctl_table;
 		port->sysctl_table = NULL;
-		unregister_sysctl_table(t->sysctl_header);
+		unregister_sysctl_table(t->devices_header);
+		unregister_sysctl_table(t->port_header);
 		kfree(t);
 	}
 	return 0;
@@ -522,30 +514,53 @@ int parport_proc_unregister(struct parport *port)
 
 int parport_device_proc_register(struct pardevice *device)
 {
+	int bytes_written, err = 0;
 	struct parport_device_sysctl_table *t;
 	struct parport * port = device->port;
+	size_t port_name_len, device_name_len, tmp_dir_path_len;
+	char *tmp_dir_path;
 	
 	t = kmemdup(&parport_device_sysctl_template, sizeof(*t), GFP_KERNEL);
 	if (t == NULL)
 		return -ENOMEM;
 
-	t->dev_dir[0].child = t->parport_dir;
-	t->parport_dir[0].child = t->port_dir;
-	t->port_dir[0].procname = port->name;
-	t->port_dir[0].child = t->devices_root_dir;
-	t->devices_root_dir[0].child = t->device_dir;
+	port_name_len = strnlen(port->name, PARPORT_NAME_MAX_LEN);
+	device_name_len = strnlen(device->name, PATH_MAX);
+
+	/* Allocate a buffer for two paths: dev/parport/PORT/devices/DEVICE. */
+	tmp_dir_path_len = PARPORT_BASE_DEVICES_PATH_SIZE + port_name_len + device_name_len;
+	tmp_dir_path = kzalloc(tmp_dir_path_len, GFP_KERNEL);
+	if (!tmp_dir_path) {
+		err = -ENOMEM;
+		goto exit_free_t;
+	}
+
+	bytes_written = snprintf(tmp_dir_path, tmp_dir_path_len, "dev/parport/%s/devices/%s",
+				 port->name, device->name);
+	if (tmp_dir_path_len <= bytes_written) {
+		err = -ENOENT;
+		goto exit_free_path;
+	}
 
-	t->device_dir[0].procname = device->name;
-	t->device_dir[0].child = t->vars;
 	t->vars[0].data = &device->timeslice;
 
-	t->sysctl_header = register_sysctl_table(t->dev_dir);
+	t->sysctl_header = register_sysctl(tmp_dir_path, t->vars);
 	if (t->sysctl_header == NULL) {
 		kfree(t);
 		t = NULL;
 	}
 	device->sysctl_table = t;
+
+	kfree(tmp_dir_path);
 	return 0;
+
+exit_free_path:
+	kfree(tmp_dir_path);
+
+exit_free_t:
+	kfree(t);
+
+	return err;
 }
 
 int parport_device_proc_unregister(struct pardevice *device)
@@ -564,7 +579,7 @@ static int __init parport_default_proc_register(void)
 	int ret;
 
 	parport_default_sysctl_table.sysctl_header =
-		register_sysctl_table(parport_default_sysctl_table.dev_dir);
+		register_sysctl("dev/parport/default", parport_default_sysctl_table.vars);
 	if (!parport_default_sysctl_table.sysctl_header)
 		return -ENOMEM;
 	ret = parport_bus_init();
diff --git a/drivers/parport/share.c b/drivers/parport/share.c
index 62f8407923d4..2d46b1d4fd69 100644
--- a/drivers/parport/share.c
+++ b/drivers/parport/share.c
@@ -467,7 +467,7 @@ struct parport *parport_register_port(unsigned long base, int irq, int dma,
 	atomic_set(&tmp->ref_count, 1);
 	INIT_LIST_HEAD(&tmp->full_list);
 
-	name = kmalloc(15, GFP_KERNEL);
+	name = kmalloc(PARPORT_NAME_MAX_LEN, GFP_KERNEL);
 	if (!name) {
 		kfree(tmp);
 		return NULL;
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index ae832e982003..4e5488975415 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -29,9 +29,8 @@ static const struct file_operations proc_sys_dir_file_operations;
 static const struct inode_operations proc_sys_dir_operations;
 
 /* Support for permanently empty directories */
-
 struct ctl_table sysctl_mount_point[] = {
-	{ }
+	{.type = SYSCTL_TABLE_TYPE_PERMANENTLY_EMPTY }
 };
 
 /**
@@ -48,21 +47,14 @@ struct ctl_table_header *register_sysctl_mount_point(const char *path)
 }
 EXPORT_SYMBOL(register_sysctl_mount_point);
 
-static bool is_empty_dir(struct ctl_table_header *head)
-{
-	return head->ctl_table[0].child == sysctl_mount_point;
-}
-
-static void set_empty_dir(struct ctl_dir *dir)
-{
-	dir->header.ctl_table[0].child = sysctl_mount_point;
-}
-
-static void clear_empty_dir(struct ctl_dir *dir)
-
-{
-	dir->header.ctl_table[0].child = NULL;
-}
+#define sysctl_is_perm_empty_ctl_table(tptr)		\
+	(tptr[0].type == SYSCTL_TABLE_TYPE_PERMANENTLY_EMPTY)
+#define sysctl_is_perm_empty_ctl_header(hptr)		\
+	(sysctl_is_perm_empty_ctl_table(hptr->ctl_table))
+#define sysctl_set_perm_empty_ctl_header(hptr)		\
+	(hptr->ctl_table[0].type = SYSCTL_TABLE_TYPE_PERMANENTLY_EMPTY)
+#define sysctl_clear_perm_empty_ctl_header(hptr)	\
+	(hptr->ctl_table[0].type = SYSCTL_TABLE_TYPE_DEFAULT)
 
 void proc_sys_poll_notify(struct ctl_table_poll *poll)
 {
@@ -230,20 +222,22 @@ static void erase_header(struct ctl_table_header *head)
 static int insert_header(struct ctl_dir *dir, struct ctl_table_header *header)
 {
 	struct ctl_table *entry;
+	struct ctl_table_header *dir_h = &dir->header;
 	int err;
 
+
 	/* Is this a permanently empty directory? */
-	if (is_empty_dir(&dir->header))
+	if (sysctl_is_perm_empty_ctl_header(dir_h))
 		return -EROFS;
 
 	/* Am I creating a permanently empty directory? */
-	if (header->ctl_table == sysctl_mount_point) {
+	if (sysctl_is_perm_empty_ctl_table(header->ctl_table)) {
 		if (!RB_EMPTY_ROOT(&dir->root))
 			return -EINVAL;
-		set_empty_dir(dir);
+		sysctl_set_perm_empty_ctl_header(dir_h);
 	}
 
-	dir->header.nreg++;
+	dir_h->nreg++;
 	header->parent = dir;
 	err = insert_links(header);
 	if (err)
@@ -259,9 +253,9 @@ fail:
 	put_links(header);
 fail_links:
 	if (header->ctl_table == sysctl_mount_point)
-		clear_empty_dir(dir);
+		sysctl_clear_perm_empty_ctl_header(dir_h);
 	header->parent = NULL;
-	drop_sysctl_table(&dir->header);
+	drop_sysctl_table(dir_h);
 	return err;
 }
 
@@ -479,7 +473,7 @@ static struct inode *proc_sys_make_inode(struct super_block *sb,
 		inode->i_mode |= S_IFDIR;
 		inode->i_op = &proc_sys_dir_operations;
 		inode->i_fop = &proc_sys_dir_file_operations;
-		if (is_empty_dir(head))
+		if (sysctl_is_perm_empty_ctl_header(head))
 			make_empty_dir_inode(inode);
 	}
 
@@ -1136,9 +1130,6 @@ static int sysctl_check_table(const char *path, struct ctl_table *table)
 	struct ctl_table *entry;
 	int err = 0;
 	list_for_each_table_entry(entry, table) {
-		if (entry->child)
-			err |= sysctl_err(path, entry, "Not a file");
-
 		if ((entry->proc_handler == proc_dostring) ||
 		    (entry->proc_handler == proc_dobool) ||
 		    (entry->proc_handler == proc_dointvec) ||
@@ -1406,7 +1397,6 @@ fail_put_dir_locked:
 	spin_unlock(&sysctl_lock);
 fail:
 	kfree(header);
-	dump_stack();
 	return NULL;
 }
 
@@ -1466,185 +1456,6 @@ void __init __register_sysctl_init(const char *path, struct ctl_table *table,
 	kmemleak_not_leak(hdr);
 }
 
-static char *append_path(const char *path, char *pos, const char *name)
-{
-	int namelen;
-	namelen = strlen(name);
-	if (((pos - path) + namelen + 2) >= PATH_MAX)
-		return NULL;
-	memcpy(pos, name, namelen);
-	pos[namelen] = '/';
-	pos[namelen + 1] = '\0';
-	pos += namelen + 1;
-	return pos;
-}
-
-static int count_subheaders(struct ctl_table *table)
-{
-	int has_files = 0;
-	int nr_subheaders = 0;
-	struct ctl_table *entry;
-
-	/* special case: no directory and empty directory */
-	if (!table || !table->procname)
-		return 1;
-
-	list_for_each_table_entry(entry, table) {
-		if (entry->child)
-			nr_subheaders += count_subheaders(entry->child);
-		else
-			has_files = 1;
-	}
-	return nr_subheaders + has_files;
-}
-
-static int register_leaf_sysctl_tables(const char *path, char *pos,
-	struct ctl_table_header ***subheader, struct ctl_table_set *set,
-	struct ctl_table *table)
-{
-	struct ctl_table *ctl_table_arg = NULL;
-	struct ctl_table *entry, *files;
-	int nr_files = 0;
-	int nr_dirs = 0;
-	int err = -ENOMEM;
-
-	list_for_each_table_entry(entry, table) {
-		if (entry->child)
-			nr_dirs++;
-		else
-			nr_files++;
-	}
-
-	files = table;
-	/* If there are mixed files and directories we need a new table */
-	if (nr_dirs && nr_files) {
-		struct ctl_table *new;
-		files = kcalloc(nr_files + 1, sizeof(struct ctl_table),
-				GFP_KERNEL);
-		if (!files)
-			goto out;
-
-		ctl_table_arg = files;
-		new = files;
-
-		list_for_each_table_entry(entry, table) {
-			if (entry->child)
-				continue;
-			*new = *entry;
-			new++;
-		}
-	}
-
-	/* Register everything except a directory full of subdirectories */
-	if (nr_files || !nr_dirs) {
-		struct ctl_table_header *header;
-		header = __register_sysctl_table(set, path, files);
-		if (!header) {
-			kfree(ctl_table_arg);
-			goto out;
-		}
-
-		/* Remember if we need to free the file table */
-		header->ctl_table_arg = ctl_table_arg;
-		**subheader = header;
-		(*subheader)++;
-	}
-
-	/* Recurse into the subdirectories. */
-	list_for_each_table_entry(entry, table) {
-		char *child_pos;
-
-		if (!entry->child)
-			continue;
-
-		err = -ENAMETOOLONG;
-		child_pos = append_path(path, pos, entry->procname);
-		if (!child_pos)
-			goto out;
-
-		err = register_leaf_sysctl_tables(path, child_pos, subheader,
-						  set, entry->child);
-		pos[0] = '\0';
-		if (err)
-			goto out;
-	}
-	err = 0;
-out:
-	/* On failure our caller will unregister all registered subheaders */
-	return err;
-}
-
-/**
- * register_sysctl_table - register a sysctl table hierarchy
- * @table: the top-level table structure
- *
- * Register a sysctl table hierarchy. @table should be a filled in ctl_table
- * array. A completely 0 filled entry terminates the table.
- * We are slowly deprecating this call so avoid its use.
- */
-struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
-{
-	struct ctl_table *ctl_table_arg = table;
-	int nr_subheaders = count_subheaders(table);
-	struct ctl_table_header *header = NULL, **subheaders, **subheader;
-	char *new_path, *pos;
-
-	pos = new_path = kmalloc(PATH_MAX, GFP_KERNEL);
-	if (!new_path)
-		return NULL;
-
-	pos[0] = '\0';
-	while (table->procname && table->child && !table[1].procname) {
-		pos = append_path(new_path, pos, table->procname);
-		if (!pos)
-			goto out;
-		table = table->child;
-	}
-	if (nr_subheaders == 1) {
-		header = __register_sysctl_table(&sysctl_table_root.default_set, new_path, table);
-		if (header)
-			header->ctl_table_arg = ctl_table_arg;
-	} else {
-		header = kzalloc(sizeof(*header) +
-				 sizeof(*subheaders)*nr_subheaders, GFP_KERNEL);
-		if (!header)
-			goto out;
-
-		subheaders = (struct ctl_table_header **) (header + 1);
-		subheader = subheaders;
-		header->ctl_table_arg = ctl_table_arg;
-
-		if (register_leaf_sysctl_tables(new_path, pos, &subheader,
-						&sysctl_table_root.default_set, table))
-			goto err_register_leaves;
-	}
-
-out:
-	kfree(new_path);
-	return header;
-
-err_register_leaves:
-	while (subheader > subheaders) {
-		struct ctl_table_header *subh = *(--subheader);
-		struct ctl_table *table = subh->ctl_table_arg;
-		unregister_sysctl_table(subh);
-		kfree(table);
-	}
-	kfree(header);
-	header = NULL;
-	goto out;
-}
-EXPORT_SYMBOL(register_sysctl_table);
-
-int __register_sysctl_base(struct ctl_table *base_table)
-{
-	struct ctl_table_header *hdr;
-
-	hdr = register_sysctl_table(base_table);
-	kmemleak_not_leak(hdr);
-	return 0;
-}
-
 static void put_links(struct ctl_table_header *header)
 {
 	struct ctl_table_set *root_set = &sysctl_table_root.default_set;
@@ -1700,35 +1511,18 @@ static void drop_sysctl_table(struct ctl_table_header *header)
 
 /**
  * unregister_sysctl_table - unregister a sysctl table hierarchy
- * @header: the header returned from register_sysctl_table
+ * @header: the header returned from register_sysctl or __register_sysctl_table
  *
  * Unregisters the sysctl table and all children. proc entries may not
  * actually be removed until they are no longer used by anyone.
  */
 void unregister_sysctl_table(struct ctl_table_header * header)
 {
-	int nr_subheaders;
 	might_sleep();
 
 	if (header == NULL)
 		return;
 
-	nr_subheaders = count_subheaders(header->ctl_table_arg);
-	if (unlikely(nr_subheaders > 1)) {
-		struct ctl_table_header **subheaders;
-		int i;
-
-		subheaders = (struct ctl_table_header **)(header + 1);
-		for (i = nr_subheaders -1; i >= 0; i--) {
-			struct ctl_table_header *subh = subheaders[i];
-			struct ctl_table *table = subh->ctl_table_arg;
-			unregister_sysctl_table(subh);
-			kfree(table);
-		}
-		kfree(header);
-		return;
-	}
-
 	spin_lock(&sysctl_lock);
 	drop_sysctl_table(header);
 	spin_unlock(&sysctl_lock);
diff --git a/fs/sysctls.c b/fs/sysctls.c
index c701273c9432..76a0aee8c229 100644
--- a/fs/sysctls.c
+++ b/fs/sysctls.c
@@ -29,11 +29,10 @@ static struct ctl_table fs_shared_sysctls[] = {
 	{ }
 };
 
-DECLARE_SYSCTL_BASE(fs, fs_shared_sysctls);
-
 static int __init init_fs_sysctls(void)
 {
-	return register_sysctl_base(fs);
+	register_sysctl_init("fs", fs_shared_sysctls);
+	return 0;
 }
 
 early_initcall(init_fs_sysctls);
diff --git a/include/linux/key.h b/include/linux/key.h
index 8dc7f7c3088b..938d7ecfb495 100644
--- a/include/linux/key.h
+++ b/include/linux/key.h
@@ -490,9 +490,6 @@ do {									\
 	rcu_assign_pointer((KEY)->payload.rcu_data0, (PAYLOAD));	\
 } while (0)
 
-#ifdef CONFIG_SYSCTL
-extern struct ctl_table key_sysctls[];
-#endif
 /*
  * the userspace interface
  */
diff --git a/include/linux/parport.h b/include/linux/parport.h
index a0bc9e0267b7..243c82d7f852 100644
--- a/include/linux/parport.h
+++ b/include/linux/parport.h
@@ -180,6 +180,8 @@ struct ieee1284_info {
 	struct semaphore irq;
 };
 
+#define PARPORT_NAME_MAX_LEN 15
+
 /* A parallel port */
 struct parport {
 	unsigned long base;	/* base address */
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 3d08277959af..59d451f455bf 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -89,7 +89,7 @@ int proc_do_static_key(struct ctl_table *table, int write, void *buffer,
 		size_t *lenp, loff_t *ppos);
 
 /*
- * Register a set of sysctl names by calling register_sysctl_table
+ * Register a set of sysctl names by calling register_sysctl
  * with an initialised array of struct ctl_table's.  An entry with 
  * NULL procname terminates the table.  table->de will be
  * set up by the registration and need not be initialised in advance.
@@ -137,7 +137,17 @@ struct ctl_table {
 	void *data;
 	int maxlen;
 	umode_t mode;
-	struct ctl_table *child;	/* Deprecated */
+	/**
+	 * enum type - Enumeration to differentiate between ctl target types
+	 * @SYSCTL_TABLE_TYPE_DEFAULT: ctl target with no special considerations
+	 * @SYSCTL_TABLE_TYPE_PERMANENTLY_EMPTY: Used to identify a permanently
+	 *                                       empty directory target to serve
+	 *                                       as mount point.
+	 */
+	enum {
+		SYSCTL_TABLE_TYPE_DEFAULT,
+		SYSCTL_TABLE_TYPE_PERMANENTLY_EMPTY
+	} type;
 	proc_handler *proc_handler;	/* Callback for text formatting */
 	struct ctl_table_poll *poll;
 	void *extra1;
@@ -197,20 +207,6 @@ struct ctl_path {
 
 #ifdef CONFIG_SYSCTL
 
-#define DECLARE_SYSCTL_BASE(_name, _table)				\
-static struct ctl_table _name##_base_table[] = {			\
-	{								\
-		.procname	= #_name,				\
-		.mode		= 0555,					\
-		.child		= _table,				\
-	},								\
-	{ },								\
-}
-
-extern int __register_sysctl_base(struct ctl_table *base_table);
-
-#define register_sysctl_base(_name) __register_sysctl_base(_name##_base_table)
-
 void proc_sys_poll_notify(struct ctl_table_poll *poll);
 
 extern void setup_sysctl_set(struct ctl_table_set *p,
@@ -222,7 +218,6 @@ struct ctl_table_header *__register_sysctl_table(
 	struct ctl_table_set *set,
 	const char *path, struct ctl_table *table);
 struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table);
-struct ctl_table_header *register_sysctl_table(struct ctl_table * table);
 void unregister_sysctl_table(struct ctl_table_header * table);
 
 extern int sysctl_init_bases(void);
@@ -244,24 +239,10 @@ extern int unaligned_enabled;
 extern int unaligned_dump_stack;
 extern int no_unaligned_warning;
 
-extern struct ctl_table sysctl_mount_point[];
+#define SYSCTL_PERM_EMPTY_DIR	(1 << 0)
 
 #else /* CONFIG_SYSCTL */
 
-#define DECLARE_SYSCTL_BASE(_name, _table)
-
-static inline int __register_sysctl_base(struct ctl_table *base_table)
-{
-	return 0;
-}
-
-#define register_sysctl_base(table) __register_sysctl_base(table)
-
-static inline struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
-{
-	return NULL;
-}
-
 static inline void register_sysctl_init(const char *path, struct ctl_table *table)
 {
 }
diff --git a/include/linux/umh.h b/include/linux/umh.h
index 5d1f6129b847..daa6a7048c11 100644
--- a/include/linux/umh.h
+++ b/include/linux/umh.h
@@ -42,8 +42,6 @@ call_usermodehelper_setup(const char *path, char **argv, char **envp,
 extern int
 call_usermodehelper_exec(struct subprocess_info *info, int wait);
 
-extern struct ctl_table usermodehelper_table[];
-
 enum umh_disable_depth {
 	UMH_ENABLED = 0,
 	UMH_FREEZING,
diff --git a/kernel/signal.c b/kernel/signal.c
index 2547fa73bde5..b5370fe5c198 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -45,6 +45,7 @@
 #include <linux/posix-timers.h>
 #include <linux/cgroup.h>
 #include <linux/audit.h>
+#include <linux/sysctl.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/signal.h>
@@ -4773,6 +4774,28 @@ static inline void siginfo_buildtime_checks(void)
 #endif
 }
 
+#if defined(CONFIG_SYSCTL)
+static struct ctl_table signal_debug_table[] = {
+#ifdef CONFIG_SYSCTL_EXCEPTION_TRACE
+	{
+		.procname	= "exception-trace",
+		.data		= &show_unhandled_signals,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec
+	},
+#endif
+	{ }
+};
+
+static int __init init_signal_sysctls(void)
+{
+	register_sysctl_init("debug", signal_debug_table);
+	return 0;
+}
+early_initcall(init_signal_sysctls);
+#endif /* CONFIG_SYSCTL */
+
 void __init signals_init(void)
 {
 	siginfo_buildtime_checks();
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index a57de67f032f..354a2d294f52 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1783,11 +1783,6 @@ static struct ctl_table kern_table[] = {
 		.proc_handler	= sysctl_max_threads,
 	},
 	{
-		.procname	= "usermodehelper",
-		.mode		= 0555,
-		.child		= usermodehelper_table,
-	},
-	{
 		.procname	= "overflowuid",
 		.data		= &overflowuid,
 		.maxlen		= sizeof(int),
@@ -1962,13 +1957,6 @@ static struct ctl_table kern_table[] = {
 		.proc_handler	= proc_dointvec,
 	},
 #endif
-#ifdef CONFIG_KEYS
-	{
-		.procname	= "keys",
-		.mode		= 0555,
-		.child		= key_sysctls,
-	},
-#endif
 #ifdef CONFIG_PERF_EVENTS
 	/*
 	 * User-space scripts rely on the existence of this file
@@ -2264,34 +2252,10 @@ static struct ctl_table vm_table[] = {
 	{ }
 };
 
-static struct ctl_table debug_table[] = {
-#ifdef CONFIG_SYSCTL_EXCEPTION_TRACE
-	{
-		.procname	= "exception-trace",
-		.data		= &show_unhandled_signals,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec
-	},
-#endif
-	{ }
-};
-
-static struct ctl_table dev_table[] = {
-	{ }
-};
-
-DECLARE_SYSCTL_BASE(kernel, kern_table);
-DECLARE_SYSCTL_BASE(vm, vm_table);
-DECLARE_SYSCTL_BASE(debug, debug_table);
-DECLARE_SYSCTL_BASE(dev, dev_table);
-
 int __init sysctl_init_bases(void)
 {
-	register_sysctl_base(kernel);
-	register_sysctl_base(vm);
-	register_sysctl_base(debug);
-	register_sysctl_base(dev);
+	register_sysctl_init("kernel", kern_table);
+	register_sysctl_init("vm", vm_table);
 
 	return 0;
 }
diff --git a/kernel/umh.c b/kernel/umh.c
index 60aa9e764a38..41088c5c39fd 100644
--- a/kernel/umh.c
+++ b/kernel/umh.c
@@ -544,7 +544,8 @@ static int proc_cap_handler(struct ctl_table *table, int write,
 	return 0;
 }
 
-struct ctl_table usermodehelper_table[] = {
+#if defined(CONFIG_SYSCTL)
+static struct ctl_table usermodehelper_table[] = {
 	{
 		.procname	= "bset",
 		.data		= &usermodehelper_bset,
@@ -561,3 +562,11 @@ struct ctl_table usermodehelper_table[] = {
 	},
 	{ }
 };
+
+static int __init init_umh_sysctls(void)
+{
+	register_sysctl_init("kernel/usermodehelper", usermodehelper_table);
+	return 0;
+}
+early_initcall(init_umh_sysctls);
+#endif /* CONFIG_SYSCTL */
diff --git a/lib/test_sysctl.c b/lib/test_sysctl.c
index e2a816d85ea2..8036aa91a1cb 100644
--- a/lib/test_sysctl.c
+++ b/lib/test_sysctl.c
@@ -30,6 +30,13 @@ static int i_zero;
 static int i_one_hundred = 100;
 static int match_int_ok = 1;
 
+
+static struct {
+	struct ctl_table_header *test_h_setup_node;
+	struct ctl_table_header *test_h_mnt;
+	struct ctl_table_header *test_h_mnterror;
+} sysctl_test_headers;
+
 struct test_sysctl_data {
 	int int_0001;
 	int int_0002;
@@ -126,9 +133,7 @@ static struct ctl_table test_table[] = {
 	{ }
 };
 
-static struct ctl_table_header *test_sysctl_header;
-
-static int __init test_sysctl_init(void)
+static void test_sysctl_calc_match_int_ok(void)
 {
 	int i;
 
@@ -153,24 +158,96 @@ static int __init test_sysctl_init(void)
 	for (i = 0; i < ARRAY_SIZE(match_int); i++)
 		if (match_int[i].defined != match_int[i].wanted)
 			match_int_ok = 0;
+}
 
+static int test_sysctl_setup_node_tests(void)
+{
+	test_sysctl_calc_match_int_ok();
 	test_data.bitmap_0001 = kzalloc(SYSCTL_TEST_BITMAP_SIZE/8, GFP_KERNEL);
 	if (!test_data.bitmap_0001)
 		return -ENOMEM;
-	test_sysctl_header = register_sysctl("debug/test_sysctl", test_table);
-	if (!test_sysctl_header) {
+	sysctl_test_headers.test_h_setup_node = register_sysctl("debug/test_sysctl", test_table);
+	if (!sysctl_test_headers.test_h_setup_node) {
 		kfree(test_data.bitmap_0001);
 		return -ENOMEM;
 	}
+
 	return 0;
 }
+
+/* Used to test that unregister actually removes the directory */
+static struct ctl_table test_table_unregister[] = {
+	{
+		.procname	= "unregister_error",
+		.data		= &test_data.int_0001,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+	},
+	{}
+};
+
+static int test_sysctl_run_unregister_nested(void)
+{
+	struct ctl_table_header *unregister;
+
+	unregister = register_sysctl("debug/test_sysctl/unregister_error",
+				   test_table_unregister);
+	if (!unregister)
+		return -ENOMEM;
+
+	unregister_sysctl_table(unregister);
+	return 0;
+}
+
+static int test_sysctl_run_register_mount_point(void)
+{
+	sysctl_test_headers.test_h_mnt
+		= register_sysctl_mount_point("debug/test_sysctl/mnt");
+	if (!sysctl_test_headers.test_h_mnt)
+		return -ENOMEM;
+
+	sysctl_test_headers.test_h_mnterror
+		= register_sysctl("debug/test_sysctl/mnt/mnt_error",
+				  test_table_unregister);
+	/*
+	 * Don't check the result.:
+	 * If it fails (expected behavior), return 0.
+	 * If successful (missbehavior of register mount point), we want to see
+	 * mnt_error when we run the sysctl test script
+	 */
+
+	return 0;
+}
+
+static int __init test_sysctl_init(void)
+{
+	int err;
+
+	err = test_sysctl_setup_node_tests();
+	if (err)
+		goto out;
+
+	err = test_sysctl_run_unregister_nested();
+	if (err)
+		goto out;
+
+	err = test_sysctl_run_register_mount_point();
+
+out:
+	return err;
+}
 module_init(test_sysctl_init);
 
 static void __exit test_sysctl_exit(void)
 {
 	kfree(test_data.bitmap_0001);
-	if (test_sysctl_header)
-		unregister_sysctl_table(test_sysctl_header);
+	if (sysctl_test_headers.test_h_setup_node)