[PATCH] Remove in-kernel init_module/cleanup_module stubs

This patch removes the default stubs for init_module and cleanup_module,
and checks for NULL instead.  It changes modpost to only create references
to those functions if they actually exist.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 10 insertions, 20 deletions

diff --git a/kernel/module.c b/kernel/module.c
index 8c17a4ce0707..8b3726655a87 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -89,13 +89,6 @@ static inline int strong_try_module_get(struct module *mod)
 	return try_module_get(mod);
 }
 
-/* Stub function for modules which don't have an initfn */
-int init_module(void)
-{
-	return 0;
-}
-EXPORT_SYMBOL(init_module);
-
 /* A thread that wants to hold a reference to a module only while it
  * is running can call ths to safely exit.
  * nfsd and lockd use this.
@@ -529,12 +522,6 @@ EXPORT_SYMBOL(module_refcount);
 /* This exists whether we can unload or not */
 static void free_module(struct module *mod);
 
-/* Stub function for modules which don't have an exitfn */
-void cleanup_module(void)
-{
-}
-EXPORT_SYMBOL(cleanup_module);
-
 static void wait_for_zero_refcount(struct module *mod)
 {
 	/* Since we might sleep for some time, drop the semaphore first */
@@ -589,7 +576,7 @@ sys_delete_module(const char __user *name_user, unsigned int flags)
 	}
 
 	/* If it has an init func, it must have an exit func to unload */
-	if ((mod->init != init_module && mod->exit == cleanup_module)
+	if ((mod->init != NULL && mod->exit == NULL)
 	    || mod->unsafe) {
 		forced = try_force(flags);
 		if (!forced) {
@@ -610,9 +597,11 @@ sys_delete_module(const char __user *name_user, unsigned int flags)
 		wait_for_zero_refcount(mod);
 
 	/* Final destruction now noone is using it. */
-	up(&module_mutex);
-	mod->exit();
-	down(&module_mutex);
+	if (mod->exit != NULL) {
+		up(&module_mutex);
+		mod->exit();
+		down(&module_mutex);
+	}
 	free_module(mod);
 
  out:
@@ -639,7 +628,7 @@ static void print_unload_info(struct seq_file *m, struct module *mod)
 		seq_printf(m, "[unsafe],");
 	}
 
-	if (mod->init != init_module && mod->exit == cleanup_module) {
+	if (mod->init != NULL && mod->exit == NULL) {
 		printed_something = 1;
 		seq_printf(m, "[permanent],");
 	}
@@ -1836,7 +1825,7 @@ sys_init_module(void __user *umod,
 		const char __user *uargs)
 {
 	struct module *mod;
-	int ret;
+	int ret = 0;
 
 	/* Must have permission */
 	if (!capable(CAP_SYS_MODULE))
@@ -1875,7 +1864,8 @@ sys_init_module(void __user *umod,
 	up(&notify_mutex);
 
 	/* Start the module */
-	ret = mod->init();
+	if (mod->init != NULL)
+		ret = mod->init();
 	if (ret < 0) {
 		/* Init routine failed: abort.  Try to protect us from
                    buggy refcounters. */