[PATCH v2 15/18] sysctl: allow registration of const struct ctl_table

From: "Thomas Weißschuh" <linux@weissschuh.net>
To: Kees Cook <keescook@chromium.org>,
	"Gustavo A. R. Silva" <gustavoars@kernel.org>,
	Luis Chamberlain <mcgrof@kernel.org>,
	Iurii Zaikin <yzaikin@google.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Joel Granados <j.granados@samsung.com>
Cc: linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-fsdevel@vger.kernel.org,
	"Thomas Weißschuh" <linux@weissschuh.net>
Subject: [PATCH v2 15/18] sysctl: allow registration of const struct ctl_table
Date: Mon, 04 Dec 2023 08:52:28 +0100	[thread overview]
Message-ID: <20231204-const-sysctl-v2-15-7a5060b11447@weissschuh.net> (raw)
In-Reply-To: <20231204-const-sysctl-v2-0-7a5060b11447@weissschuh.net>

This allows sysctl table to be put into read-only data.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 fs/proc/proc_sysctl.c  |  6 +++---
 include/linux/sysctl.h | 10 +++++-----
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index e7fd1680d479..d09107a5b43f 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -1356,7 +1356,7 @@ 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;
@@ -1417,7 +1417,7 @@ 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,
@@ -1446,7 +1446,7 @@ 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);
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 2f4d577f2e93..7c96d5abafc7 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -229,13 +229,13 @@ 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))
@@ -257,7 +257,7 @@ 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)
 {
 }
 
@@ -267,7 +267,7 @@ 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;

-- 
2.43.0

