From: Rusty Russell <rusty@rustcorp.com.au>
Date: Sat, 7 Feb 2009 07:45:56 +0000 (+1030)
Subject: module: remove over-zealous check in __module_get()
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=7f9a50a5b89b87f8e754f59ae9968da28be618a5;p=linux-beck.git

module: remove over-zealous check in __module_get()

Impact: fix spurious BUG_ON() triggered under load

module_refcount() isn't reliable outside stop_machine(), as demonstrated
by Karsten Keil <kkeil@suse.de>, networking can trigger it under load
(an inc on one cpu and dec on another while module_refcount() is tallying
 can give false results, for example).

Almost noone should be using __module_get, but that's another issue.

Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/include/linux/module.h b/include/linux/module.h
index f3b8329eb5b8..145a75528cc1 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -407,7 +407,6 @@ static inline local_t *__module_ref_addr(struct module *mod, int cpu)
 static inline void __module_get(struct module *module)
 {
 	if (module) {
-		BUG_ON(module_refcount(module) == 0);
 		local_inc(__module_ref_addr(module, get_cpu()));
 		put_cpu();
 	}