[PATCH v4 1/4] modules: split part of complete_formation() into prepare_coming_module()

[Jessica Yu]

Put all actions that are performed after module->state is set to
MODULE_STATE_COMING in complete_formation() into a separate function
prepare_coming_module(). This prepares for the removal of ftrace and
livepatch module coming notifiers and instead the corresponding work will
be done in prepare_coming_module(). This split will also allow for
appropriate error handling.

Signed-off-by: Jessica Yu <jeyu@xxxxxxxxxx>
---
 kernel/module.c | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/kernel/module.c b/kernel/module.c
index 9537da3..a174335 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3366,6 +3366,14 @@ out_unlocked:
 	return err;
 }
 
+static int prepare_coming_module(struct module *mod)
+{
+
+	blocking_notifier_call_chain(&module_notify_list,
+				     MODULE_STATE_COMING, mod);
+	return 0;
+}
+
 static int complete_formation(struct module *mod, struct load_info *info)
 {
 	int err;
@@ -3389,8 +3397,6 @@ static int complete_formation(struct module *mod, struct load_info *info)
 	mod->state = MODULE_STATE_COMING;
 	mutex_unlock(&module_mutex);
 
-	blocking_notifier_call_chain(&module_notify_list,
-				     MODULE_STATE_COMING, mod);
 	return 0;
 
 out:
@@ -3512,13 +3518,17 @@ static int load_module(struct load_info *info, const char __user *uargs,
 	if (err)
 		goto ddebug_cleanup;
 
+	err = prepare_coming_module(mod);
+	if (err)
+		goto bug_cleanup;
+
 	/* Module is ready to execute: parsing args may do that. */
 	after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
 				  -32768, 32767, mod,
 				  unknown_module_param_cb);
 	if (IS_ERR(after_dashes)) {
 		err = PTR_ERR(after_dashes);
-		goto bug_cleanup;
+		goto coming_cleanup;
 	} else if (after_dashes) {
 		pr_warn("%s: parameters '%s' after `--' ignored\n",
 		       mod->name, after_dashes);
@@ -3527,7 +3537,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
 	/* Link in to syfs. */
 	err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
 	if (err < 0)
-		goto bug_cleanup;
+		goto coming_cleanup;
 
 	/* Get rid of temporary copy. */
 	free_copy(info);
@@ -3537,15 +3547,16 @@ static int load_module(struct load_info *info, const char __user *uargs,
 
 	return do_init_module(mod);
 
+ coming_cleanup:
+	blocking_notifier_call_chain(&module_notify_list,
+				     MODULE_STATE_GOING, mod);
+
  bug_cleanup:
 	/* module_bug_cleanup needs module_mutex protection */
 	mutex_lock(&module_mutex);
 	module_bug_cleanup(mod);
 	mutex_unlock(&module_mutex);
 
-	blocking_notifier_call_chain(&module_notify_list,
-				     MODULE_STATE_GOING, mod);
-
 	/* we can't deallocate the module until we clear memory protection */
 	module_disable_ro(mod);
 	module_disable_nx(mod);
-- 
2.4.3