[RFC PATCH 07/29] lsm: rework lsm_active_cnt and lsm_idlist[]

[Paul Moore]

Move the LSM count and lsm_id list declarations out of a header that is
visible across the kernel and into a header that is limited to the LSM
framework.  This not only helps keep the include/linux headers smaller
and cleaner, it helps prevent misuse of these variables.

During the move, lsm_active_cnt was renamed to lsm_count for the sake
of brevity.

Signed-off-by: Paul Moore <paul at paul-moore.com>
---
 include/linux/security.h | 2 --
 security/lsm.h           | 5 +++++
 security/lsm_init.c      | 8 +-------
 security/lsm_syscalls.c  | 8 +++++---
 security/security.c      | 3 +++
 5 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index cc9b54d95d22..8aac21787a9f 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -167,8 +167,6 @@ struct lsm_prop {
 };
 
 extern const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1];
-extern u32 lsm_active_cnt;
-extern const struct lsm_id *lsm_idlist[];
 
 /* These functions are in security/commoncap.c */
 extern int cap_capable(const struct cred *cred, struct user_namespace *ns,
diff --git a/security/lsm.h b/security/lsm.h
index 0e1731bad4a7..af343072199d 100644
--- a/security/lsm.h
+++ b/security/lsm.h
@@ -7,6 +7,11 @@
 #define _LSM_H_
 
 #include <linux/lsm_hooks.h>
+#include <linux/lsm_count.h>
+
+/* List of configured LSMs */
+extern unsigned int lsm_count;
+extern const struct lsm_id *lsm_idlist[];
 
 /* LSM blob configuration */
 extern struct lsm_blob_sizes blob_sizes;
diff --git a/security/lsm_init.c b/security/lsm_init.c
index edf2f4140eaa..981ddb20f48e 100644
--- a/security/lsm_init.c
+++ b/security/lsm_init.c
@@ -22,8 +22,8 @@ static __initdata const char *lsm_order_cmdline;
 static __initdata const char *lsm_order_legacy;
 
 /* Ordered list of LSMs to initialize. */
-static __initdata struct lsm_info *lsm_order[MAX_LSM_COUNT + 1];
 static __initdata struct lsm_info *lsm_exclusive;
+static __initdata struct lsm_info *lsm_order[MAX_LSM_COUNT + 1];
 
 static __initdata bool debug;
 #define init_debug(...)							\
@@ -211,12 +211,6 @@ static void __init initialize_lsm(struct lsm_info *lsm)
 	}
 }
 
-/*
- * Current index to use while initializing the lsm id list.
- */
-u32 lsm_active_cnt __ro_after_init;
-const struct lsm_id *lsm_idlist[MAX_LSM_COUNT];
-
 /* Populate ordered LSMs list from comma-separated LSM name list. */
 static void __init ordered_lsm_parse(const char *order, const char *origin)
 {
diff --git a/security/lsm_syscalls.c b/security/lsm_syscalls.c
index 8440948a690c..3fb0d77ae65c 100644
--- a/security/lsm_syscalls.c
+++ b/security/lsm_syscalls.c
@@ -17,6 +17,8 @@
 #include <linux/lsm_hooks.h>
 #include <uapi/linux/lsm.h>
 
+#include "lsm.h"
+
 /**
  * lsm_name_to_attr - map an LSM attribute name to its ID
  * @name: name of the attribute
@@ -96,7 +98,7 @@ SYSCALL_DEFINE4(lsm_get_self_attr, unsigned int, attr, struct lsm_ctx __user *,
 SYSCALL_DEFINE3(lsm_list_modules, u64 __user *, ids, u32 __user *, size,
 		u32, flags)
 {
-	u32 total_size = lsm_active_cnt * sizeof(*ids);
+	u32 total_size = lsm_count * sizeof(*ids);
 	u32 usize;
 	int i;
 
@@ -112,9 +114,9 @@ SYSCALL_DEFINE3(lsm_list_modules, u64 __user *, ids, u32 __user *, size,
 	if (usize < total_size)
 		return -E2BIG;
 
-	for (i = 0; i < lsm_active_cnt; i++)
+	for (i = 0; i < lsm_count; i++)
 		if (put_user(lsm_idlist[i]->id, ids++))
 			return -EFAULT;
 
-	return lsm_active_cnt;
+	return lsm_count;
 }
diff --git a/security/security.c b/security/security.c
index 8d370a4c5e74..a3e8dd640b39 100644
--- a/security/security.c
+++ b/security/security.c
@@ -73,6 +73,9 @@ const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX + 1] = {
 	[LOCKDOWN_CONFIDENTIALITY_MAX] = "confidentiality",
 };
 
+unsigned int lsm_count __ro_after_init;
+const struct lsm_id *lsm_idlist[MAX_LSM_COUNT];
+
 struct lsm_blob_sizes blob_sizes;
 
 struct kmem_cache *lsm_file_cache;
-- 
2.49.0