security: introduce CONFIG_SECURITY_WRITABLE_HOOKS
Subsequent patches will add RO hardening to LSM hooks, however, SELinux
still needs to be able to perform runtime disablement after init to handle
architectures where init-time disablement via boot parameters is not feasible.
Introduce a new kernel configuration parameter CONFIG_SECURITY_WRITABLE_HOOKS,
and a helper macro __lsm_ro_after_init, to handle this case.
Signed-off-by: James Morris <james.l.morris@oracle.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Kees Cook <keescook@chromium.org>
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index ba3049f..1aa6333 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1920,6 +1920,13 @@
}
#endif /* CONFIG_SECURITY_SELINUX_DISABLE */
+/* Currently required to handle SELinux runtime hook disable. */
+#ifdef CONFIG_SECURITY_WRITABLE_HOOKS
+#define __lsm_ro_after_init
+#else
+#define __lsm_ro_after_init __ro_after_init
+#endif /* CONFIG_SECURITY_WRITABLE_HOOKS */
+
extern int __init security_module_enable(const char *module);
extern void __init capability_add_hooks(void);
#ifdef CONFIG_SECURITY_YAMA