1 files changed, 46 insertions, 44 deletions

diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index bf06344a42cc..c88854df0b62 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -19,8 +19,9 @@
 #include <linux/kmemleak.h>
 #include "internal.h"
 
-#define list_for_each_table_entry(entry, table) \
-	for ((entry) = (table); (entry)->procname; (entry)++)
+#define list_for_each_table_entry(entry, header)	\
+	entry = header->ctl_table;			\
+	for (size_t i = 0 ; i < header->ctl_table_size && entry->procname; ++i, entry++)
 
 static const struct dentry_operations proc_sys_dentry_operations;
 static const struct file_operations proc_sys_file_operations;
@@ -43,7 +44,7 @@ static struct ctl_table sysctl_mount_point[] = {
  */
 struct ctl_table_header *register_sysctl_mount_point(const char *path)
 {
-	return register_sysctl(path, sysctl_mount_point);
+	return register_sysctl_sz(path, sysctl_mount_point, 0);
 }
 EXPORT_SYMBOL(register_sysctl_mount_point);
 
@@ -188,9 +189,10 @@ static void erase_entry(struct ctl_table_header *head, struct ctl_table *entry)
 
 static void init_header(struct ctl_table_header *head,
 	struct ctl_table_root *root, struct ctl_table_set *set,
-	struct ctl_node *node, struct ctl_table *table)
+	struct ctl_node *node, struct ctl_table *table, size_t table_size)
 {
 	head->ctl_table = table;
+	head->ctl_table_size = table_size;
 	head->ctl_table_arg = table;
 	head->used = 0;
 	head->count = 1;
@@ -204,7 +206,7 @@ static void init_header(struct ctl_table_header *head,
 	if (node) {
 		struct ctl_table *entry;
 
-		list_for_each_table_entry(entry, table) {
+		list_for_each_table_entry(entry, head) {
 			node->header = head;
 			node++;
 		}
@@ -215,7 +217,7 @@ static void erase_header(struct ctl_table_header *head)
 {
 	struct ctl_table *entry;
 
-	list_for_each_table_entry(entry, head->ctl_table)
+	list_for_each_table_entry(entry, head)
 		erase_entry(head, entry);
 }
 
@@ -242,7 +244,7 @@ static int insert_header(struct ctl_dir *dir, struct ctl_table_header *header)
 	err = insert_links(header);
 	if (err)
 		goto fail_links;
-	list_for_each_table_entry(entry, header->ctl_table) {
+	list_for_each_table_entry(entry, header) {
 		err = insert_entry(header, entry);
 		if (err)
 			goto fail;
@@ -973,7 +975,7 @@ static struct ctl_dir *new_dir(struct ctl_table_set *set,
 	memcpy(new_name, name, namelen);
 	table[0].procname = new_name;
 	table[0].mode = S_IFDIR|S_IRUGO|S_IXUGO;
-	init_header(&new->header, set->dir.header.root, set, node, table);
+	init_header(&new->header, set->dir.header.root, set, node, table, 1);
 
 	return new;
 }
@@ -1125,11 +1127,11 @@ static int sysctl_check_table_array(const char *path, struct ctl_table *table)
 	return err;
 }
 
-static int sysctl_check_table(const char *path, struct ctl_table *table)
+static int sysctl_check_table(const char *path, struct ctl_table_header *header)
 {
 	struct ctl_table *entry;
 	int err = 0;
-	list_for_each_table_entry(entry, table) {
+	list_for_each_table_entry(entry, header) {
 		if ((entry->proc_handler == proc_dostring) ||
 		    (entry->proc_handler == proc_dobool) ||
 		    (entry->proc_handler == proc_dointvec) ||
@@ -1159,8 +1161,7 @@ static int sysctl_check_table(const char *path, struct ctl_table *table)
 	return err;
 }
 
-static struct ctl_table_header *new_links(struct ctl_dir *dir, struct ctl_table *table,
-	struct ctl_table_root *link_root)
+static struct ctl_table_header *new_links(struct ctl_dir *dir, struct ctl_table_header *head)
 {
 	struct ctl_table *link_table, *entry, *link;
 	struct ctl_table_header *links;
@@ -1170,7 +1171,7 @@ static struct ctl_table_header *new_links(struct ctl_dir *dir, struct ctl_table
 
 	name_bytes = 0;
 	nr_entries = 0;
-	list_for_each_table_entry(entry, table) {
+	list_for_each_table_entry(entry, head) {
 		nr_entries++;
 		name_bytes += strlen(entry->procname) + 1;
 	}
@@ -1189,31 +1190,33 @@ static struct ctl_table_header *new_links(struct ctl_dir *dir, struct ctl_table
 	link_name = (char *)&link_table[nr_entries + 1];
 	link = link_table;
 
-	list_for_each_table_entry(entry, table) {
+	list_for_each_table_entry(entry, head) {
 		int len = strlen(entry->procname) + 1;
 		memcpy(link_name, entry->procname, len);
 		link->procname = link_name;
 		link->mode = S_IFLNK|S_IRWXUGO;
-		link->data = link_root;
+		link->data = head->root;
 		link_name += len;
 		link++;
 	}
-	init_header(links, dir->header.root, dir->header.set, node, link_table);
+	init_header(links, dir->header.root, dir->header.set, node, link_table,
+		    head->ctl_table_size);
 	links->nreg = nr_entries;
 
 	return links;
 }
 
 static bool get_links(struct ctl_dir *dir,
-	struct ctl_table *table, struct ctl_table_root *link_root)
+		      struct ctl_table_header *header,
+		      struct ctl_table_root *link_root)
 {
-	struct ctl_table_header *head;
+	struct ctl_table_header *tmp_head;
 	struct ctl_table *entry, *link;
 
 	/* Are there links available for every entry in table? */
-	list_for_each_table_entry(entry, table) {
+	list_for_each_table_entry(entry, header) {
 		const char *procname = entry->procname;
-		link = find_entry(&head, dir, procname, strlen(procname));
+		link = find_entry(&tmp_head, dir, procname, strlen(procname));
 		if (!link)
 			return false;
 		if (S_ISDIR(link->mode) && S_ISDIR(entry->mode))
@@ -1224,10 +1227,10 @@ static bool get_links(struct ctl_dir *dir,
 	}
 
 	/* The checks passed.  Increase the registration count on the links */
-	list_for_each_table_entry(entry, table) {
+	list_for_each_table_entry(entry, header) {
 		const char *procname = entry->procname;
-		link = find_entry(&head, dir, procname, strlen(procname));
-		head->nreg++;
+		link = find_entry(&tmp_head, dir, procname, strlen(procname));
+		tmp_head->nreg++;
 	}
 	return true;
 }
@@ -1246,13 +1249,13 @@ static int insert_links(struct ctl_table_header *head)
 	if (IS_ERR(core_parent))
 		return 0;
 
-	if (get_links(core_parent, head->ctl_table, head->root))
+	if (get_links(core_parent, head, head->root))
 		return 0;
 
 	core_parent->header.nreg++;
 	spin_unlock(&sysctl_lock);
 
-	links = new_links(core_parent, head->ctl_table, head->root);
+	links = new_links(core_parent, head);
 
 	spin_lock(&sysctl_lock);
 	err = -ENOMEM;
@@ -1260,7 +1263,7 @@ static int insert_links(struct ctl_table_header *head)
 		goto out;
 
 	err = 0;
-	if (get_links(core_parent, head->ctl_table, head->root)) {
+	if (get_links(core_parent, head, head->root)) {
 		kfree(links);
 		goto out;
 	}
@@ -1310,6 +1313,7 @@ static struct ctl_dir *sysctl_mkdir_p(struct ctl_dir *dir, const char *path)
  * 	 should not be free'd after registration. So it should not be
  * 	 used on stack. It can either be a global or dynamically allocated
  * 	 by the caller and free'd later after sysctl unregistration.
+ * @table_size : The number of elements in table
  *
  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
  * array. A completely 0 filled entry terminates the table.
@@ -1352,26 +1356,21 @@ static struct ctl_dir *sysctl_mkdir_p(struct ctl_dir *dir, const char *path)
  */
 struct ctl_table_header *__register_sysctl_table(
 	struct ctl_table_set *set,
-	const char *path, struct ctl_table *table)
+	const char *path, struct ctl_table *table, size_t table_size)
 {
 	struct ctl_table_root *root = set->dir.header.root;
 	struct ctl_table_header *header;
 	struct ctl_dir *dir;
-	struct ctl_table *entry;
 	struct ctl_node *node;
-	int nr_entries = 0;
-
-	list_for_each_table_entry(entry, table)
-		nr_entries++;
 
 	header = kzalloc(sizeof(struct ctl_table_header) +
-			 sizeof(struct ctl_node)*nr_entries, GFP_KERNEL_ACCOUNT);
+			 sizeof(struct ctl_node)*table_size, GFP_KERNEL_ACCOUNT);
 	if (!header)
 		return NULL;
 
 	node = (struct ctl_node *)(header + 1);
-	init_header(header, root, set, node, table);
-	if (sysctl_check_table(path, table))
+	init_header(header, root, set, node, table, table_size);
+	if (sysctl_check_table(path, header))
 		goto fail;
 
 	spin_lock(&sysctl_lock);
@@ -1401,7 +1400,7 @@ fail:
 }
 
 /**
- * register_sysctl - register a sysctl table
+ * register_sysctl_sz - register a sysctl table
  * @path: The path to the directory the sysctl table is in. If the path
  * 	doesn't exist we will create it for you.
  * @table: the table structure. The calller must ensure the life of the @table
@@ -1411,18 +1410,20 @@ fail:
  * 	to call unregister_sysctl_table() and can instead use something like
  * 	register_sysctl_init() which does not care for the result of the syctl
  * 	registration.
+ * @table_size: The number of elements in table.
  *
  * Register a sysctl table. @table should be a filled in ctl_table
  * array. A completely 0 filled entry terminates the table.
  *
  * See __register_sysctl_table for more details.
  */
-struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table)
+struct ctl_table_header *register_sysctl_sz(const char *path, struct ctl_table *table,
+					    size_t table_size)
 {
 	return __register_sysctl_table(&sysctl_table_root.default_set,
-					path, table);
+					path, table, table_size);
 }
-EXPORT_SYMBOL(register_sysctl);
+EXPORT_SYMBOL(register_sysctl_sz);
 
 /**
  * __register_sysctl_init() - register sysctl table to path
@@ -1433,6 +1434,7 @@ EXPORT_SYMBOL(register_sysctl);
  * 	lifetime use of the sysctl.
  * @table_name: The name of sysctl table, only used for log printing when
  *              registration fails
+ * @table_size: The number of elements in table
  *
  * The sysctl interface is used by userspace to query or modify at runtime
  * a predefined value set on a variable. These variables however have default
@@ -1445,12 +1447,12 @@ EXPORT_SYMBOL(register_sysctl);
  * Context: if your base directory does not exist it will be created for you.
  */
 void __init __register_sysctl_init(const char *path, struct ctl_table *table,
-				 const char *table_name)
+				 const char *table_name, size_t table_size)
 {
-	struct ctl_table_header *hdr = register_sysctl(path, table);
+	struct ctl_table_header *hdr = register_sysctl_sz(path, table, table_size);
 
 	if (unlikely(!hdr)) {
-		pr_err("failed when register_sysctl %s to %s\n", table_name, path);
+		pr_err("failed when register_sysctl_sz %s to %s\n", table_name, path);
 		return;
 	}
 	kmemleak_not_leak(hdr);
@@ -1471,7 +1473,7 @@ static void put_links(struct ctl_table_header *header)
 	if (IS_ERR(core_parent))
 		return;
 
-	list_for_each_table_entry(entry, header->ctl_table) {
+	list_for_each_table_entry(entry, header) {
 		struct ctl_table_header *link_head;
 		struct ctl_table *link;
 		const char *name = entry->procname;
@@ -1535,7 +1537,7 @@ void setup_sysctl_set(struct ctl_table_set *set,
 {
 	memset(set, 0, sizeof(*set));
 	set->is_seen = is_seen;
-	init_header(&set->dir.header, root, set, NULL, root_table);
+	init_header(&set->dir.header, root, set, NULL, root_table, 1);
 }
 
 void retire_sysctl_set(struct ctl_table_set *set)