security: Convert LSM into a static interface

Convert LSM into a static interface, as the ability to unload a security
module is not required by in-tree users and potentially complicates the
overall security architecture.

Needlessly exported LSM symbols have been unexported, to help reduce API
abuse.

Parameters for the capability and root_plug modules are now specified
at boot.

The SECURITY_FRAMEWORK_VERSION macro has also been removed.

In a nutshell, there is no safe way to unload an LSM.  The modular interface
is thus unecessary and broken infrastructure.  It is used only by out-of-tree
modules, which are often binary-only, illegal, abusive of the API and
dangerous, e.g.  silently re-vectoring SELinux.

[akpm@linux-foundation.org: cleanups]
[akpm@linux-foundation.org: USB Kconfig fix]
[randy.dunlap@oracle.com: fix LSM kernel-doc]
Signed-off-by: NJames Morris <jmorris@namei.org>
Acked-by: NChris Wright <chrisw@sous-sol.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: "Serge E. Hallyn" <serue@us.ibm.com>
Acked-by: NArjan van de Ven <arjan@infradead.org>
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Documentation/DocBook/kernel-api.tmpl

@@ -340,7 +340,7 @@ X!Earch/x86/kernel/mca_32.c
 
   <chapter id="security">
      <title>Security Framework</title>
-!Esecurity/security.c
+!Isecurity/security.c
   </chapter>
 
   <chapter id="audit">

Documentation/kernel-parameters.txt

@@ -75,10 +75,12 @@ parameter is applicable:
 	PPT	Parallel port support is enabled.
 	PS2	Appropriate PS/2 support is enabled.
 	RAM	RAM disk support is enabled.
+	ROOTPLUG The example Root Plug LSM is enabled.
 	S390	S390 architecture is enabled.
 	SCSI	Appropriate SCSI support is enabled.
 			A lot of drivers has their options described inside of
 			Documentation/scsi/.
+	SECURITY Different security models are enabled.
 	SELINUX SELinux support is enabled.
 	SERIAL	Serial support is enabled.
 	SH	SuperH architecture is enabled.
@@ -373,6 +375,12 @@ and is between 256 and 4096 characters. It is defined in the file
 			possible to determine what the correct size should be.
 			This option provides an override for these situations.
 
+	capability.disable=
+			[SECURITY] Disable capabilities.  This would normally
+			be used only if an alternative security model is to be
+			configured.  Potentially dangerous and should only be
+			used if you are entirely sure of the consequences.
+
 	chandev=	[HW,NET] Generic channel device initialisation
 
 	checkreqprot	[SELINUX] Set initial checkreqprot flag value.
@@ -1539,6 +1547,15 @@ and is between 256 and 4096 characters. It is defined in the file
 			Useful for devices that are detected asynchronously
 			(e.g. USB and MMC devices).
 
+	root_plug.vendor_id=
+			[ROOTPLUG] Override the default vendor ID
+
+	root_plug.product_id=
+			[ROOTPLUG] Override the default product ID
+
+	root_plug.debug=
+			[ROOTPLUG] Enable debugging output
+
 	rw		[KNL] Mount root device read-write on boot
 
 	S		[KNL] Run init in single mode

security/Kconfig

@@ -74,15 +74,15 @@ config SECURITY_NETWORK_XFRM
 	  If you are unsure how to answer this question, answer N.
 
 config SECURITY_CAPABILITIES
-	tristate "Default Linux Capabilities"
+	bool "Default Linux Capabilities"
 	depends on SECURITY
 	help
 	  This enables the "default" Linux capabilities functionality.
 	  If you are unsure how to answer this question, answer Y.
 
 config SECURITY_ROOTPLUG
-	tristate "Root Plug Support"
-	depends on USB && SECURITY
+	bool "Root Plug Support"
+	depends on USB=y && SECURITY
 	help
 	  This is a sample LSM module that should only be used as such.
 	  It prevents any programs running with egid == 0 if a specific

security/capability.c

@@ -8,7 +8,6 @@
  *
  */
 
-#include <linux/module.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/security.h>
@@ -52,7 +51,6 @@ static int secondary;
 
 static int capability_disable;
 module_param_named(disable, capability_disable, int, 0);
-MODULE_PARM_DESC(disable, "To disable capabilities module set disable = 1");
 
 static int __init capability_init (void)
 {
@@ -75,26 +73,4 @@ static int __init capability_init (void)
 	return 0;
 }
 
-static void __exit capability_exit (void)
-{
-	if (capability_disable)
-		return;
-	/* remove ourselves from the security framework */
-	if (secondary) {
-		if (mod_unreg_security (KBUILD_MODNAME, &capability_ops))
-			printk (KERN_INFO "Failure unregistering capabilities "
-				"with primary module.\n");
-		return;
-	}
-
-	if (unregister_security (&capability_ops)) {
-		printk (KERN_INFO
-			"Failure unregistering capabilities with the kernel\n");
-	}
-}
-
 security_initcall (capability_init);
-module_exit (capability_exit);
-
-MODULE_DESCRIPTION("Standard Linux Capabilities Security Module");
-MODULE_LICENSE("GPL");

security/commoncap.c

@@ -339,6 +339,3 @@ EXPORT_SYMBOL(cap_task_post_setuid);
 EXPORT_SYMBOL(cap_task_reparent_to_init);
 EXPORT_SYMBOL(cap_syslog);
 EXPORT_SYMBOL(cap_vm_enough_memory);
-
-MODULE_DESCRIPTION("Standard Linux Common Capabilities Security Module");
-MODULE_LICENSE("GPL");

security/dummy.c

@@ -15,7 +15,6 @@
 #undef DEBUG
 
 #include <linux/capability.h>
-#include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/mman.h>
 #include <linux/pagemap.h>

security/root_plug.c

@@ -22,11 +22,11 @@
  *	License.
  */
 
-#include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/security.h>
 #include <linux/usb.h>
+#include <linux/moduleparam.h>
 
 /* flag to keep track of how we were registered */
 static int secondary;
@@ -36,22 +36,14 @@ static int vendor_id = 0x0557;
 static int product_id = 0x2008;
 
 module_param(vendor_id, uint, 0400);
-MODULE_PARM_DESC(vendor_id, "USB Vendor ID of device to look for");
-
 module_param(product_id, uint, 0400);
-MODULE_PARM_DESC(product_id, "USB Product ID of device to look for");
 
 /* should we print out debug messages */
 static int debug = 0;
 
 module_param(debug, bool, 0600);
-MODULE_PARM_DESC(debug, "Debug enabled or not");
 
-#if defined(CONFIG_SECURITY_ROOTPLUG_MODULE)
-#define MY_NAME THIS_MODULE->name
-#else
 #define MY_NAME "root_plug"
-#endif
 
 #define root_dbg(fmt, arg...)					\
 	do {							\
@@ -117,25 +109,4 @@ static int __init rootplug_init (void)
 	return 0;
 }
 
-static void __exit rootplug_exit (void)
-{
-	/* remove ourselves from the security framework */
-	if (secondary) {
-		if (mod_unreg_security (MY_NAME, &rootplug_security_ops))
-			printk (KERN_INFO "Failure unregistering Root Plug "
-				" module with primary module.\n");
-	} else { 
-		if (unregister_security (&rootplug_security_ops)) {
-			printk (KERN_INFO "Failure unregistering Root Plug "
-				"module with the kernel\n");
-		}
-	}
-	printk (KERN_INFO "Root Plug module removed\n");
-}
-
 security_initcall (rootplug_init);
-module_exit (rootplug_exit);
-
-MODULE_DESCRIPTION("Root Plug sample LSM module, written for Linux Journal article");
-MODULE_LICENSE("GPL");
-

security/selinux/hooks.c

@@ -22,7 +22,6 @@
  *      as published by the Free Software Foundation.
  */
 
-#include <linux/module.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/ptrace.h>
@@ -86,6 +85,7 @@
 extern unsigned int policydb_loaded_version;
 extern int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm);
 extern int selinux_compat_net;
+extern struct security_operations *security_ops;
 
 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
 int selinux_enforcing = 0;

security/selinux/xfrm.c

@@ -31,7 +31,6 @@
  *   2. Emulating a reasonable SO_PEERSEC across machines
  *   3. Testing addition of sk_policy's with security context via setsockopt
  */
-#include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/security.h>