Commit 7abc9b53 authored by Thomas Weißschuh's avatar Thomas Weißschuh Committed by Joel Granados
Browse files

sysctl: allow registration of const struct ctl_table 



Putting structure, especially those containing function pointers,
into read-only memory makes the safer and easier to reason about.
Change the sysctl registration APIs to allow registration of
"const struct ctl_table".

Signed-off-by: default avatarThomas Weißschuh <linux@weissschuh.net>
Acked-by: default avatarKees Cook <keescook@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org> # security/*
Signed-off-by: default avatarJoel Granados <joel.granados@kernel.org>
parent 29e1095b

fs/proc/proc_sysctl.c

+3 −3
Original line number Diff line number Diff line
@@ -1359,7 +1359,7 @@ 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;
@@ -1420,7 +1420,7 @@ 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,
@@ -1449,7 +1449,7 @@ 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);

include/linux/sysctl.h

+5 −5
Original line number Diff line number Diff line
@@ -223,13 +223,13 @@ 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 +251,7 @@ 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 +261,7 @@ 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;