[POC 18/23] module: Refactor add_unformed_module()
From: Petr Mladek <pmladek@suse.com>
Date: 2020-01-17 15:04:15
Also in:
lkml
Subsystem:
the rest · Maintainer:
Linus Torvalds
The livepatching code will need to add another condition to avoid
waiting. Let's make the code slightly less hairy.
Of course, it is a matter of taste. The main ideas of refactoring:
+ Make it clear what happens when old->state == MODULE_STATE_LIVE.
+ Make it more clear when we are leaving the function immediately
and when we are doing some extra actions.
+ Be able to add another check that has to be done outside
module_mutex and can result into an immediate return.
Signed-off-by: Petr Mladek <pmladek@suse.com>
---
kernel/module.c | 28 +++++++++++++++-------------
1 file changed, 15 insertions(+), 13 deletions(-)
diff --git a/kernel/module.c b/kernel/module.c
index b3f11524f8f9..ac45d465ff23 100644
--- a/kernel/module.c
+++ b/kernel/module.c@@ -3721,28 +3721,30 @@ static int add_unformed_module(struct module *mod) again: mutex_lock(&module_mutex); old = find_module_all(mod->name, strlen(mod->name), true); + if (old != NULL) { - if (old->state != MODULE_STATE_LIVE) { - /* Wait in case it fails to load. */ + if (old->state == MODULE_STATE_LIVE) { mutex_unlock(&module_mutex); - err = wait_event_interruptible(module_wq, - finished_loading(mod->name)); - if (err) - goto out_unlocked; - goto again; + return -EEXIST; } - err = -EEXIST; - goto out; + + /* Wait in case it fails to load. */ + mutex_unlock(&module_mutex); + err = wait_event_interruptible(module_wq, + finished_loading(mod->name)); + if (err) + return err; + + /* Did the load succeded or failed? */ + goto again; } + mod_update_bounds(mod); list_add_rcu(&mod->list, &modules); mod_tree_insert(mod); - err = 0; -out: mutex_unlock(&module_mutex); -out_unlocked: - return err; + return 0; } static int complete_formation(struct module *mod, struct load_info *info)
--
2.16.4