[PATCH 03/11] sysctl: Add ctl_table_size to ctl_table_header

From: Joel Granados
Date: Wed Jun 21 2023 - 05:11:17 EST


The new ctl_table_size element will hold the size of the ctl_table
contained in the header. This value is passed by the callers to the
sysctl register infra.
Add a new macro that uses the size to traverse the ctl_table in the
header. This moves away from using the last empty element in the
ctl_table array as a stop post

Signed-off-by: Joel Granados <j.granados@xxxxxxxxxxx>
---
include/linux/sysctl.h | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 59d451f455bf..33252ad58ebe 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -159,12 +159,22 @@ struct ctl_node {
struct ctl_table_header *header;
};

-/* struct ctl_table_header is used to maintain dynamic lists of
- struct ctl_table trees. */
+/**
+ * struct ctl_table_header - maintains dynamic lists of struct ctl_table trees
+ * @ctl_table: pointer to the first element in ctl_table array
+ * @ctl_table_size: number of elements pointed by @ctl_table
+ * @used: The entry will never be touched when equal to 0.
+ * @count: Upped every time something is added to @inodes and downed every time
+ * something is removed from inodes
+ * @nreg: When nreg drops to 0 the ctl_table_header will be unregistered.
+ * @rcu: Delays the freeing of the inode. Introduced with "unfuck proc_sysctl ->d_compare()"
+ *
+ */
struct ctl_table_header {
union {
struct {
struct ctl_table *ctl_table;
+ int ctl_table_size;
int used;
int count;
int nreg;
--
2.30.2