LoadPin: Initialize as ordered LSM

This converts LoadPin from being a direct "minor" LSM into an ordered LSM.
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>

include/linux/lsm_hooks.h

@@ -2095,10 +2095,5 @@ extern void __init yama_add_hooks(void);
 #else
 static inline void __init yama_add_hooks(void) { }
 #endif
-#ifdef CONFIG_SECURITY_LOADPIN
-void __init loadpin_add_hooks(void);
-#else
-static inline void loadpin_add_hooks(void) { };
-#endif
 
 #endif /* ! __LINUX_LSM_HOOKS_H */

security/Kconfig

@@ -239,46 +239,9 @@ source "security/yama/Kconfig"
 
 source "security/integrity/Kconfig"
 
-choice
-	prompt "Default security module"
-	default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX
-	default DEFAULT_SECURITY_SMACK if SECURITY_SMACK
-	default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO
-	default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR
-	default DEFAULT_SECURITY_DAC
-
-	help
-	  Select the security module that will be used by default if the
-	  kernel parameter security= is not specified.
-
-	config DEFAULT_SECURITY_SELINUX
-		bool "SELinux" if SECURITY_SELINUX=y
-
-	config DEFAULT_SECURITY_SMACK
-		bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y
-
-	config DEFAULT_SECURITY_TOMOYO
-		bool "TOMOYO" if SECURITY_TOMOYO=y
-
-	config DEFAULT_SECURITY_APPARMOR
-		bool "AppArmor" if SECURITY_APPARMOR=y
-
-	config DEFAULT_SECURITY_DAC
-		bool "Unix Discretionary Access Controls"
-
-endchoice
-
-config DEFAULT_SECURITY
-	string
-	default "selinux" if DEFAULT_SECURITY_SELINUX
-	default "smack" if DEFAULT_SECURITY_SMACK
-	default "tomoyo" if DEFAULT_SECURITY_TOMOYO
-	default "apparmor" if DEFAULT_SECURITY_APPARMOR
-	default "" if DEFAULT_SECURITY_DAC
-
 config LSM
 	string "Ordered list of enabled LSMs"
-	default "integrity"
+	default "loadpin,integrity,selinux,smack,tomoyo,apparmor"
 	help
 	  A comma-separated list of LSMs, in initialization order.
 	  Any LSMs left off this list will be ignored. This can be

security/loadpin/loadpin.c

@@ -187,13 +187,19 @@ static struct security_hook_list loadpin_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(kernel_load_data, loadpin_load_data),
 };
 
-void __init loadpin_add_hooks(void)
+static int __init loadpin_init(void)
 {
 	pr_info("ready to pin (currently %senforcing)\n",
 		enforce ? "" : "not ");
 	security_add_hooks(loadpin_hooks, ARRAY_SIZE(loadpin_hooks), "loadpin");
+	return 0;
 }
 
+DEFINE_LSM(loadpin) = {
+	.name = "loadpin",
+	.init = loadpin_init,
+};
+
 /* Should not be mutable after boot, so not listed in sysfs (perm == 0). */
 module_param(enforce, int, 0);
 MODULE_PARM_DESC(enforce, "Enforce module/firmware pinning");

security/security.c

@@ -275,7 +275,6 @@ int __init security_init(void)
 	 */
 	capability_add_hooks();
 	yama_add_hooks();
-	loadpin_add_hooks();
 
 	/* Load LSMs in specified order. */
 	ordered_lsm_init();