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From:   Joel Granados <j.granados@samsung.com>
To:     <mcgrof@kernel.org>, Kees Cook <keescook@chromium.org>,
        Iurii Zaikin <yzaikin@google.com>
CC:     Joel Granados <j.granados@samsung.com>,
        <linux-kernel@vger.kernel.org>, <linux-fsdevel@vger.kernel.org>
Subject: [PATCH 03/11] sysctl: Add ctl_table_size to ctl_table_header
Date:   Wed, 21 Jun 2023 11:09:52 +0200
Message-ID: <20230621091000.424843-4-j.granados@samsung.com>
In-Reply-To: <20230621091000.424843-1-j.granados@samsung.com>
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References: <20230621091000.424843-1-j.granados@samsung.com>
        <CGME20230621091009eucas1p1e4fa56beb44e49e4d1160bfac6eb59ec@eucas1p1.samsung.com>
Precedence: bulk

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@samsung.com>
---
 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