Merge tag 'sysctl-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl

Pull sysctl updates from Joel Granados:

 - Remove sentinel elements from ctl_table structs in kernel/*

   Removing sentinels in ctl_table arrays reduces the build time size
   and runtime memory consumed by ~64 bytes per array. Removals for
   net/, io_uring/, mm/, ipc/ and security/ are set to go into mainline
   through their respective subsystems making the next release the most
   likely place where the final series that removes the check for
   proc_name == NULL will land.

   This adds to removals already in arch/, drivers/ and fs/.

 - Adjust ctl_table definitions and references to allow constification
     - Remove unused ctl_table function arguments
     - Move non-const elements from ctl_table to ctl_table_header
     - Make ctl_table pointers const in ctl_table_root structure

   Making the static ctl_table structs const will increase safety by
   keeping the pointers to proc_handler functions in .rodata. Though no
   ctl_tables where made const in this PR, the ground work for making
   that possible has started with these changes sent by Thomas
   Weißschuh.

* tag 'sysctl-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl:
  sysctl: drop now unnecessary out-of-bounds check
  sysctl: move sysctl type to ctl_table_header
  sysctl: drop sysctl_is_perm_empty_ctl_table
  sysctl: treewide: constify argument ctl_table_root::permissions(table)
  sysctl: treewide: drop unused argument ctl_table_root::set_ownership(table)
  bpf: Remove the now superfluous sentinel elements from ctl_table array
  delayacct: Remove the now superfluous sentinel elements from ctl_table array
  kprobes: Remove the now superfluous sentinel elements from ctl_table array
  printk: Remove the now superfluous sentinel elements from ctl_table array
  scheduler: Remove the now superfluous sentinel elements from ctl_table array
  seccomp: Remove the now superfluous sentinel elements from ctl_table array
  timekeeping: Remove the now superfluous sentinel elements from ctl_table array
  ftrace: Remove the now superfluous sentinel elements from ctl_table array
  umh: Remove the now superfluous sentinel elements from ctl_table array
  kernel misc: Remove the now superfluous sentinel elements from ctl_table array

1 files changed, 9 insertions, 12 deletions

diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 37cde0efee57..b1c2c0b82116 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -30,9 +30,7 @@ static const struct file_operations proc_sys_dir_file_operations;
 static const struct inode_operations proc_sys_dir_operations;
 
 /* Support for permanently empty directories */
-static struct ctl_table sysctl_mount_point[] = {
-	{.type = SYSCTL_TABLE_TYPE_PERMANENTLY_EMPTY }
-};
+static struct ctl_table sysctl_mount_point[] = { };
 
 /**
  * register_sysctl_mount_point() - registers a sysctl mount point
@@ -48,14 +46,12 @@ struct ctl_table_header *register_sysctl_mount_point(const char *path)
 }
 EXPORT_SYMBOL(register_sysctl_mount_point);
 
-#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))
+	(hptr->type == SYSCTL_TABLE_TYPE_PERMANENTLY_EMPTY)
 #define sysctl_set_perm_empty_ctl_header(hptr)		\
-	(hptr->ctl_table[0].type = SYSCTL_TABLE_TYPE_PERMANENTLY_EMPTY)
+	(hptr->type = SYSCTL_TABLE_TYPE_PERMANENTLY_EMPTY)
 #define sysctl_clear_perm_empty_ctl_header(hptr)	\
-	(hptr->ctl_table[0].type = SYSCTL_TABLE_TYPE_DEFAULT)
+	(hptr->type = SYSCTL_TABLE_TYPE_DEFAULT)
 
 void proc_sys_poll_notify(struct ctl_table_poll *poll)
 {
@@ -210,6 +206,8 @@ static void init_header(struct ctl_table_header *head,
 			node++;
 		}
 	}
+	if (table == sysctl_mount_point)
+		sysctl_set_perm_empty_ctl_header(head);
 }
 
 static void erase_header(struct ctl_table_header *head)
@@ -232,8 +230,7 @@ static int insert_header(struct ctl_dir *dir, struct ctl_table_header *header)
 		return -EROFS;
 
 	/* Am I creating a permanently empty directory? */
-	if (header->ctl_table_size > 0 &&
-	    sysctl_is_perm_empty_ctl_table(header->ctl_table)) {
+	if (sysctl_is_perm_empty_ctl_header(header)) {
 		if (!RB_EMPTY_ROOT(&dir->root))
 			return -EINVAL;
 		sysctl_set_perm_empty_ctl_header(dir_h);
@@ -480,7 +477,7 @@ static struct inode *proc_sys_make_inode(struct super_block *sb,
 	}
 
 	if (root->set_ownership)
-		root->set_ownership(head, table, &inode->i_uid, &inode->i_gid);
+		root->set_ownership(head, &inode->i_uid, &inode->i_gid);
 	else {
 		inode->i_uid = GLOBAL_ROOT_UID;
 		inode->i_gid = GLOBAL_ROOT_GID;
@@ -1204,7 +1201,7 @@ static bool get_links(struct ctl_dir *dir,
 	struct ctl_table *entry, *link;
 
 	if (header->ctl_table_size == 0 ||
-	    sysctl_is_perm_empty_ctl_table(header->ctl_table))
+	    sysctl_is_perm_empty_ctl_header(header))
 		return true;
 
 	/* Are there links available for every entry in table? */