[patch 17/53] module: remove over-zealous check in __module_get()

[Greg KH]

2.6.28-stable review patch.  If anyone has any objections, please let us know.
------------------

From: Rusty Russell <rusty@xxxxxxxxxxxxxxx>

commit 7f9a50a5b89b87f8e754f59ae9968da28be618a5 upstream.

Impact: fix spurious BUG_ON() triggered under load

module_refcount() isn't reliable outside stop_machine(), as demonstrated
by Karsten Keil <kkeil@xxxxxxx>, 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@xxxxxxx>
Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 include/linux/module.h |    1 -
 1 file changed, 1 deletion(-)

--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -391,7 +391,6 @@ void symbol_put_addr(void *addr);
 static inline void __module_get(struct module *module)
 {
 	if (module) {
-		BUG_ON(module_refcount(module) == 0);
 		local_inc(&module->ref[get_cpu()].count);
 		put_cpu();
 	}

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