Summary

* sysctl ctl_table constification
 
   Constifying ctl_table structs prevents the modification of proc_handler
   function pointers. All ctl_table struct arguments are const qualified in the
   sysctl API in such a way that the ctl_table arrays being defined elsewhere
   and passed through sysctl can be constified one-by-one. We kick the
   constification off by qualifying user_table in kernel/ucount.c and expect all
   the ctl_tables to be constified in the coming releases.
 
 * Misc fixes
 
   Adjust comments in two places to better reflect the code. Remove superfluous
   dput calls. Remove Luis from sysctl maintainership. Replace comments about
   holding a lock with calls to lockdep_assert_held.
 
 * Testing
 
   All these went through 0-day and they have all been in linux-next for at
   least 1 month (since Oct-24). I also rand these through the sysctl selftest
   for x86_64.
 -----BEGIN PGP SIGNATURE-----
 
 iQGzBAABCgAdFiEErkcJVyXmMSXOyyeQupfNUreWQU8FAmdAXMsACgkQupfNUreW
 QU/KfQv8Daq9sew98ohmS/lkdoE1dfpI72motzEn1993CbLjN2h3CZauaHjBPFnr
 rpr8qPrphdWTyDbDMgx63oxcNxM07g7a9H0y/K3IwdUsx7fGINgHF5kfWeVn09ov
 X8I3NuL/+xSHAZRsLQeBykbY6BD5e0uuxL6ayGzkejrgRd+80dmC3MzXqX207v1z
 rlrUFXEXwqKYgxP/H+pxmvmVWKAeFsQt/E49GOkg2qSg9mVFhtKpxHwMJVqS2a8u
 qAKHgcZhB5T8TQSb1eKnyCzXLDLpzqUBj9ejqJSsQm16fweawv221Ji6a1k53QYG
 chreoB9R8qCZ/jGoWI3ZKGRZ/Vl37l+GF/82X/sDrMbKwVlxvaERpb1KXrnh/D1v
 qNze1Eea0eYv22weGGEa3J5N2tKfgX6NcRFioDNe9VEXX6zDcAtJKTKZtbMB3gXX
 CzQicH5yXApyAk3aNCq0S3s+WRQR0syGAYCmtxhaRgXRnSu9qifKZ1XhZQyhgKIG
 Flt9MsU2
 =bOJ0
 -----END PGP SIGNATURE-----

Merge tag 'sysctl-6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl

Pull sysctl updates from Joel Granados:
 "sysctl ctl_table constification:

   - Constifying ctl_table structs prevents the modification of
     proc_handler function pointers. All ctl_table struct arguments are
     const qualified in the sysctl API in such a way that the ctl_table
     arrays being defined elsewhere and passed through sysctl can be
     constified one-by-one.

     We kick the constification off by qualifying user_table in
     kernel/ucount.c and expect all the ctl_tables to be constified in
     the coming releases.

  Misc fixes:

   - Adjust comments in two places to better reflect the code

   - Remove superfluous dput calls

   - Remove Luis from sysctl maintainership

   - Replace comments about holding a lock with calls to
     lockdep_assert_held"

* tag 'sysctl-6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl:
  sysctl: Reduce dput(child) calls in proc_sys_fill_cache()
  sysctl: Reorganize kerneldoc parameter names
  ucounts: constify sysctl table user_table
  sysctl: update comments to new registration APIs
  MAINTAINERS: remove me from sysctl
  sysctl: Convert locking comments to lockdep assertions
  const_structs.checkpatch: add ctl_table
  sysctl: make internal ctl_tables const
  sysctl: allow registration of const struct ctl_table
  sysctl: move internal interfaces to const struct ctl_table
  bpf: Constify ctl_table argument of filter function

MAINTAINERS

@@ -18641,7 +18641,6 @@ F:	include/linux/proc_fs.h
 F:	tools/testing/selftests/proc/
 
 PROC SYSCTL
-M:	Luis Chamberlain <mcgrof@kernel.org>
 M:	Kees Cook <kees@kernel.org>
 M:	Joel Granados <joel.granados@kernel.org>
 L:	linux-kernel@vger.kernel.org

fs/proc/internal.h

@@ -102,7 +102,7 @@ struct proc_inode {
 	union proc_op op;
 	struct proc_dir_entry *pde;
 	struct ctl_table_header *sysctl;
-	struct ctl_table *sysctl_entry;
+	const struct ctl_table *sysctl_entry;
 	struct hlist_node sibling_inodes;
 	const struct proc_ns_operations *ns_ops;
 	struct inode vfs_inode;

fs/proc/proc_sysctl.c

@@ -17,6 +17,7 @@
 #include <linux/bpf-cgroup.h>
 #include <linux/mount.h>
 #include <linux/kmemleak.h>
+#include <linux/lockdep.h>
 #include "internal.h"
 
 #define list_for_each_table_entry(entry, header)	\
@@ -33,7 +34,7 @@ static const struct inode_operations proc_sys_dir_operations;
  * Support for permanently empty directories.
  * Must be non-empty to avoid sharing an address with other tables.
  */
-static struct ctl_table sysctl_mount_point[] = {
+static const struct ctl_table sysctl_mount_point[] = {
 	{ }
 };
 
@@ -67,7 +68,7 @@ void proc_sys_poll_notify(struct ctl_table_poll *poll)
 	wake_up_interruptible(&poll->wait);
 }
 
-static struct ctl_table root_table[] = {
+static const struct ctl_table root_table[] = {
 	{
 		.procname = "",
 		.mode = S_IFDIR|S_IRUGO|S_IXUGO,
@@ -88,7 +89,7 @@ static DEFINE_SPINLOCK(sysctl_lock);
 
 static void drop_sysctl_table(struct ctl_table_header *header);
 static int sysctl_follow_link(struct ctl_table_header **phead,
-	struct ctl_table **pentry);
+	const struct ctl_table **pentry);
 static int insert_links(struct ctl_table_header *head);
 static void put_links(struct ctl_table_header *header);
 
@@ -109,14 +110,15 @@ static int namecmp(const char *name1, int len1, const char *name2, int len2)
 	return cmp;
 }
 
-/* Called under sysctl_lock */
-static struct ctl_table *find_entry(struct ctl_table_header **phead,
+static const struct ctl_table *find_entry(struct ctl_table_header **phead,
 	struct ctl_dir *dir, const char *name, int namelen)
 {
 	struct ctl_table_header *head;
-	struct ctl_table *entry;
+	const struct ctl_table *entry;
 	struct rb_node *node = dir->root.rb_node;
 
+	lockdep_assert_held(&sysctl_lock);
+
 	while (node)
 	{
 		struct ctl_node *ctl_node;
@@ -141,7 +143,7 @@ static struct ctl_table *find_entry(struct ctl_table_header **phead,
 	return NULL;
 }
 
-static int insert_entry(struct ctl_table_header *head, struct ctl_table *entry)
+static int insert_entry(struct ctl_table_header *head, const struct ctl_table *entry)
 {
 	struct rb_node *node = &head->node[entry - head->ctl_table].node;
 	struct rb_node **p = &head->parent->root.rb_node;
@@ -151,7 +153,7 @@ static int insert_entry(struct ctl_table_header *head, struct ctl_table *entry)
 
 	while (*p) {
 		struct ctl_table_header *parent_head;
-		struct ctl_table *parent_entry;
+		const struct ctl_table *parent_entry;
 		struct ctl_node *parent_node;
 		const char *parent_name;
 		int cmp;
@@ -180,7 +182,7 @@ static int insert_entry(struct ctl_table_header *head, struct ctl_table *entry)
 	return 0;
 }
 
-static void erase_entry(struct ctl_table_header *head, struct ctl_table *entry)
+static void erase_entry(struct ctl_table_header *head, const struct ctl_table *entry)
 {
 	struct rb_node *node = &head->node[entry - head->ctl_table].node;
 
@@ -189,7 +191,7 @@ 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, size_t table_size)
+	struct ctl_node *node, const struct ctl_table *table, size_t table_size)
 {
 	head->ctl_table = table;
 	head->ctl_table_size = table_size;
@@ -204,7 +206,7 @@ static void init_header(struct ctl_table_header *head,
 	head->node = node;
 	INIT_HLIST_HEAD(&head->inodes);
 	if (node) {
-		struct ctl_table *entry;
+		const struct ctl_table *entry;
 
 		list_for_each_table_entry(entry, head) {
 			node->header = head;
@@ -217,7 +219,7 @@ static void init_header(struct ctl_table_header *head,
 
 static void erase_header(struct ctl_table_header *head)
 {
-	struct ctl_table *entry;
+	const struct ctl_table *entry;
 
 	list_for_each_table_entry(entry, head)
 		erase_entry(head, entry);
@@ -225,7 +227,7 @@ 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;
+	const struct ctl_table *entry;
 	struct ctl_table_header *dir_h = &dir->header;
 	int err;
 
@@ -263,18 +265,20 @@ static int insert_header(struct ctl_dir *dir, struct ctl_table_header *header)
 	return err;
 }
 
-/* called under sysctl_lock */
 static int use_table(struct ctl_table_header *p)
 {
+	lockdep_assert_held(&sysctl_lock);
+
 	if (unlikely(p->unregistering))
 		return 0;
 	p->used++;
 	return 1;
 }
 
-/* called under sysctl_lock */
 static void unuse_table(struct ctl_table_header *p)
 {
+	lockdep_assert_held(&sysctl_lock);
+
 	if (!--p->used)
 		if (unlikely(p->unregistering))
 			complete(p->unregistering);
@@ -285,9 +289,11 @@ static void proc_sys_invalidate_dcache(struct ctl_table_header *head)
 	proc_invalidate_siblings_dcache(&head->inodes, &sysctl_lock);
 }
 
-/* called under sysctl_lock, will reacquire if has to wait */
 static void start_unregistering(struct ctl_table_header *p)
 {
+	/* will reacquire if has to wait */
+	lockdep_assert_held(&sysctl_lock);
+
 	/*
 	 * if p->used is 0, nobody will ever touch that entry again;
 	 * we'll eliminate all paths to it before dropping sysctl_lock
@@ -344,12 +350,12 @@ lookup_header_set(struct ctl_table_root *root)
 	return set;
 }
 
-static struct ctl_table *lookup_entry(struct ctl_table_header **phead,
-				      struct ctl_dir *dir,
-				      const char *name, int namelen)
+static const struct ctl_table *lookup_entry(struct ctl_table_header **phead,
+					    struct ctl_dir *dir,
+					    const char *name, int namelen)
 {
 	struct ctl_table_header *head;
-	struct ctl_table *entry;
+	const struct ctl_table *entry;
 
 	spin_lock(&sysctl_lock);
 	entry = find_entry(&head, dir, name, namelen);
@@ -374,10 +380,10 @@ static struct ctl_node *first_usable_entry(struct rb_node *node)
 }
 
 static void first_entry(struct ctl_dir *dir,
-	struct ctl_table_header **phead, struct ctl_table **pentry)
+	struct ctl_table_header **phead, const struct ctl_table **pentry)
 {
 	struct ctl_table_header *head = NULL;
-	struct ctl_table *entry = NULL;
+	const struct ctl_table *entry = NULL;
 	struct ctl_node *ctl_node;
 
 	spin_lock(&sysctl_lock);
@@ -391,10 +397,10 @@ static void first_entry(struct ctl_dir *dir,
 	*pentry = entry;
 }
 
-static void next_entry(struct ctl_table_header **phead, struct ctl_table **pentry)
+static void next_entry(struct ctl_table_header **phead, const struct ctl_table **pentry)
 {
 	struct ctl_table_header *head = *phead;
-	struct ctl_table *entry = *pentry;
+	const struct ctl_table *entry = *pentry;
 	struct ctl_node *ctl_node = &head->node[entry - head->ctl_table];
 
 	spin_lock(&sysctl_lock);
@@ -427,7 +433,7 @@ static int test_perm(int mode, int op)
 	return -EACCES;
 }
 
-static int sysctl_perm(struct ctl_table_header *head, struct ctl_table *table, int op)
+static int sysctl_perm(struct ctl_table_header *head, const struct ctl_table *table, int op)
 {
 	struct ctl_table_root *root = head->root;
 	int mode;
@@ -441,7 +447,7 @@ static int sysctl_perm(struct ctl_table_header *head, struct ctl_table *table, i
 }
 
 static struct inode *proc_sys_make_inode(struct super_block *sb,
-		struct ctl_table_header *head, struct ctl_table *table)
+		struct ctl_table_header *head, const struct ctl_table *table)
 {
 	struct ctl_table_root *root = head->root;
 	struct inode *inode;
@@ -512,7 +518,7 @@ static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry,
 	struct ctl_table_header *head = grab_header(dir);
 	struct ctl_table_header *h = NULL;
 	const struct qstr *name = &dentry->d_name;
-	struct ctl_table *p;
+	const struct ctl_table *p;
 	struct inode *inode;
 	struct dentry *err = ERR_PTR(-ENOENT);
 	struct ctl_dir *ctl_dir;
@@ -550,7 +556,7 @@ static ssize_t proc_sys_call_handler(struct kiocb *iocb, struct iov_iter *iter,
 {
 	struct inode *inode = file_inode(iocb->ki_filp);
 	struct ctl_table_header *head = grab_header(inode);
-	struct ctl_table *table = PROC_I(inode)->sysctl_entry;
+	const struct ctl_table *table = PROC_I(inode)->sysctl_entry;
 	size_t count = iov_iter_count(iter);
 	char *kbuf;
 	ssize_t error;
@@ -624,7 +630,7 @@ static ssize_t proc_sys_write(struct kiocb *iocb, struct iov_iter *iter)
 static int proc_sys_open(struct inode *inode, struct file *filp)
 {
 	struct ctl_table_header *head = grab_header(inode);
-	struct ctl_table *table = PROC_I(inode)->sysctl_entry;
+	const struct ctl_table *table = PROC_I(inode)->sysctl_entry;
 
 	/* sysctl was unregistered */
 	if (IS_ERR(head))
@@ -642,7 +648,7 @@ static __poll_t proc_sys_poll(struct file *filp, poll_table *wait)
 {
 	struct inode *inode = file_inode(filp);
 	struct ctl_table_header *head = grab_header(inode);
-	struct ctl_table *table = PROC_I(inode)->sysctl_entry;
+	const struct ctl_table *table = PROC_I(inode)->sysctl_entry;
 	__poll_t ret = DEFAULT_POLLMASK;
 	unsigned long event;
 
@@ -673,7 +679,7 @@ static __poll_t proc_sys_poll(struct file *filp, poll_table *wait)
 static bool proc_sys_fill_cache(struct file *file,
 				struct dir_context *ctx,
 				struct ctl_table_header *head,
-				struct ctl_table *table)
+				const struct ctl_table *table)
 {
 	struct dentry *child, *dir = file->f_path.dentry;
 	struct inode *inode;
@@ -698,11 +704,11 @@ static bool proc_sys_fill_cache(struct file *file,
 			res = d_splice_alias(inode, child);
 			d_lookup_done(child);
 			if (unlikely(res)) {
-				if (IS_ERR(res)) {
-					dput(child);
-					return false;
-				}
 				dput(child);
+
+				if (IS_ERR(res))
+					return false;
+
 				child = res;
 			}
 		}
@@ -717,7 +723,7 @@ static bool proc_sys_fill_cache(struct file *file,
 static bool proc_sys_link_fill_cache(struct file *file,
 				    struct dir_context *ctx,
 				    struct ctl_table_header *head,
-				    struct ctl_table *table)
+				    const struct ctl_table *table)
 {
 	bool ret = true;
 
@@ -735,7 +741,7 @@ static bool proc_sys_link_fill_cache(struct file *file,
 	return ret;
 }
 
-static int scan(struct ctl_table_header *head, struct ctl_table *table,
+static int scan(struct ctl_table_header *head, const struct ctl_table *table,
 		unsigned long *pos, struct file *file,
 		struct dir_context *ctx)
 {
@@ -759,7 +765,7 @@ static int proc_sys_readdir(struct file *file, struct dir_context *ctx)
 {
 	struct ctl_table_header *head = grab_header(file_inode(file));
 	struct ctl_table_header *h = NULL;
-	struct ctl_table *entry;
+	const struct ctl_table *entry;
 	struct ctl_dir *ctl_dir;
 	unsigned long pos;
 
@@ -792,7 +798,7 @@ static int proc_sys_permission(struct mnt_idmap *idmap,
 	 * are _NOT_ writeable, capabilities or not.
 	 */
 	struct ctl_table_header *head;
-	struct ctl_table *table;
+	const struct ctl_table *table;
 	int error;
 
 	/* Executable files are not allowed under /proc/sys/ */
@@ -836,7 +842,7 @@ static int proc_sys_getattr(struct mnt_idmap *idmap,
 {
 	struct inode *inode = d_inode(path->dentry);
 	struct ctl_table_header *head = grab_header(inode);
-	struct ctl_table *table = PROC_I(inode)->sysctl_entry;
+	const struct ctl_table *table = PROC_I(inode)->sysctl_entry;
 
 	if (IS_ERR(head))
 		return PTR_ERR(head);
@@ -935,7 +941,7 @@ static struct ctl_dir *find_subdir(struct ctl_dir *dir,
 				   const char *name, int namelen)
 {
 	struct ctl_table_header *head;
-	struct ctl_table *entry;
+	const struct ctl_table *entry;
 
 	entry = find_entry(&head, dir, name, namelen);
 	if (!entry)
@@ -1046,12 +1052,12 @@ static struct ctl_dir *xlate_dir(struct ctl_table_set *set, struct ctl_dir *dir)
 }
 
 static int sysctl_follow_link(struct ctl_table_header **phead,
-	struct ctl_table **pentry)
+	const struct ctl_table **pentry)
 {
 	struct ctl_table_header *head;
+	const struct ctl_table *entry;
 	struct ctl_table_root *root;
 	struct ctl_table_set *set;
-	struct ctl_table *entry;
 	struct ctl_dir *dir;
 	int ret;
 
@@ -1078,7 +1084,7 @@ static int sysctl_follow_link(struct ctl_table_header **phead,
 	return ret;
 }
 
-static int sysctl_err(const char *path, struct ctl_table *table, char *fmt, ...)
+static int sysctl_err(const char *path, const struct ctl_table *table, char *fmt, ...)
 {
 	struct va_format vaf;
 	va_list args;
@@ -1094,7 +1100,7 @@ static int sysctl_err(const char *path, struct ctl_table *table, char *fmt, ...)
 	return -EINVAL;
 }
 
-static int sysctl_check_table_array(const char *path, struct ctl_table *table)
+static int sysctl_check_table_array(const char *path, const struct ctl_table *table)
 {
 	unsigned int extra;
 	int err = 0;
@@ -1133,7 +1139,7 @@ static int sysctl_check_table_array(const char *path, struct ctl_table *table)
 
 static int sysctl_check_table(const char *path, struct ctl_table_header *header)
 {
-	struct ctl_table *entry;
+	const struct ctl_table *entry;
 	int err = 0;
 	list_for_each_table_entry(entry, header) {
 		if (!entry->procname)
@@ -1169,8 +1175,9 @@ static int sysctl_check_table(const char *path, struct ctl_table_header *header)
 
 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 *link_table, *link;
 	struct ctl_table_header *links;
+	const struct ctl_table *entry;
 	struct ctl_node *node;
 	char *link_name;
 	int name_bytes;
@@ -1215,7 +1222,7 @@ static bool get_links(struct ctl_dir *dir,
 		      struct ctl_table_root *link_root)
 {
 	struct ctl_table_header *tmp_head;
-	struct ctl_table *entry, *link;
+	const struct ctl_table *entry, *link;
 
 	if (header->ctl_table_size == 0 ||
 	    sysctl_is_perm_empty_ctl_header(header))
@@ -1358,7 +1365,7 @@ 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, size_t table_size)
+	const char *path, const struct ctl_table *table, size_t table_size)
 {
 	struct ctl_table_root *root = set->dir.header.root;
 	struct ctl_table_header *header;
@@ -1419,7 +1426,7 @@ struct ctl_table_header *__register_sysctl_table(
  *
  * See __register_sysctl_table for more details.
  */
-struct ctl_table_header *register_sysctl_sz(const char *path, struct ctl_table *table,
+struct ctl_table_header *register_sysctl_sz(const char *path, const struct ctl_table *table,
 					    size_t table_size)
 {
 	return __register_sysctl_table(&sysctl_table_root.default_set,
@@ -1448,7 +1455,7 @@ EXPORT_SYMBOL(register_sysctl_sz);
  *
  * 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,
+void __init __register_sysctl_init(const char *path, const struct ctl_table *table,
 				 const char *table_name, size_t table_size)
 {
 	struct ctl_table_header *hdr = register_sysctl_sz(path, table, table_size);
@@ -1466,7 +1473,7 @@ static void put_links(struct ctl_table_header *header)
 	struct ctl_table_root *root = header->root;
 	struct ctl_dir *parent = header->parent;
 	struct ctl_dir *core_parent;
-	struct ctl_table *entry;
+	const struct ctl_table *entry;
 
 	if (header->set == root_set)
 		return;
@@ -1477,7 +1484,7 @@ static void put_links(struct ctl_table_header *header)
 
 	list_for_each_table_entry(entry, header) {
 		struct ctl_table_header *link_head;
-		struct ctl_table *link;
+		const struct ctl_table *link;
 		const char *name = entry->procname;
 
 		link = find_entry(&link_head, core_parent, name, strlen(name));

include/linux/bpf-cgroup.h

@@ -138,7 +138,7 @@ int __cgroup_bpf_check_dev_permission(short dev_type, u32 major, u32 minor,
 				      short access, enum cgroup_bpf_attach_type atype);
 
 int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
-				   struct ctl_table *table, int write,
+				   const struct ctl_table *table, int write,
 				   char **buf, size_t *pcount, loff_t *ppos,
 				   enum cgroup_bpf_attach_type atype);
 

include/linux/sysctl.h

@@ -90,9 +90,7 @@ int proc_do_static_key(const struct ctl_table *table, int write, void *buffer,
 
 /*
  * 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.
+ * with an initialised array of struct ctl_table's.
  *
  * sysctl names can be mirrored automatically under /proc/sys.  The
  * procname supplied controls /proc naming.
@@ -133,7 +131,7 @@ static inline void *proc_sys_poll_event(struct ctl_table_poll *poll)
 
 /* A sysctl table is an array of struct ctl_table: */
 struct ctl_table {
-	const char *procname;		/* Text ID for /proc/sys, or zero */
+	const char *procname;		/* Text ID for /proc/sys */
 	void *data;
 	int maxlen;
 	umode_t mode;
@@ -162,7 +160,7 @@ struct ctl_node {
 struct ctl_table_header {
 	union {
 		struct {
-			struct ctl_table *ctl_table;
+			const struct ctl_table *ctl_table;
 			int ctl_table_size;
 			int used;
 			int count;
@@ -223,13 +221,13 @@ extern void retire_sysctl_set(struct ctl_table_set *set);
 
 struct ctl_table_header *__register_sysctl_table(
 	struct ctl_table_set *set,
-	const char *path, struct ctl_table *table, size_t table_size);
-struct ctl_table_header *register_sysctl_sz(const char *path, struct ctl_table *table,
+	const char *path, const struct ctl_table *table, size_t table_size);
+struct ctl_table_header *register_sysctl_sz(const char *path, const struct ctl_table *table,
 					    size_t table_size);
 void unregister_sysctl_table(struct ctl_table_header * table);
 
 extern int sysctl_init_bases(void);
-extern void __register_sysctl_init(const char *path, struct ctl_table *table,
+extern void __register_sysctl_init(const char *path, const struct ctl_table *table,
 				 const char *table_name, size_t table_size);
 #define register_sysctl_init(path, table)	\
 	__register_sysctl_init(path, table, #table, ARRAY_SIZE(table))
@@ -251,7 +249,7 @@ extern int no_unaligned_warning;
 
 #else /* CONFIG_SYSCTL */
 
-static inline void register_sysctl_init(const char *path, struct ctl_table *table)
+static inline void register_sysctl_init(const char *path, const struct ctl_table *table)
 {
 }
 
@@ -261,7 +259,7 @@ static inline struct ctl_table_header *register_sysctl_mount_point(const char *p
 }
 
 static inline struct ctl_table_header *register_sysctl_sz(const char *path,
-							  struct ctl_table *table,
+							  const struct ctl_table *table,
 							  size_t table_size)
 {
 	return NULL;

kernel/bpf/cgroup.c

@@ -1708,7 +1708,7 @@ const struct bpf_verifier_ops cg_dev_verifier_ops = {
  * returned value != 1 during execution. In all other cases 0 is returned.
  */
 int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
-				   struct ctl_table *table, int write,
+				   const struct ctl_table *table, int write,
 				   char **buf, size_t *pcount, loff_t *ppos,
 				   enum cgroup_bpf_attach_type atype)
 {

kernel/sysctl.c

@@ -1305,7 +1305,6 @@ int proc_dointvec_userhz_jiffies(const struct ctl_table *table, int write,
  * @write: %TRUE if this is a write to the sysctl file
  * @buffer: the user buffer
  * @lenp: the size of the user buffer
- * @ppos: file position
  * @ppos: the current position in the file
  *
  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer

kernel/ucount.c

@@ -70,7 +70,7 @@ static long ue_int_max = INT_MAX;
 		.extra1		= &ue_zero,			\
 		.extra2		= &ue_int_max,			\
 	}
-static struct ctl_table user_table[] = {
+static const struct ctl_table user_table[] = {
 	UCOUNT_ENTRY("max_user_namespaces"),
 	UCOUNT_ENTRY("max_pid_namespaces"),
 	UCOUNT_ENTRY("max_uts_namespaces"),

scripts/const_structs.checkpatch

@@ -6,6 +6,7 @@ bus_type
 clk_ops
 comedi_lrange
 component_ops
+ctl_table
 dentry_operations
 dev_pm_ops
 device_type