[patch 10/56] module: remove over-zealous check in __module_get()

Greg KH
2009-02-11T00:31:40Z

[-- Attachment #1: module-remove-over-zealous-check-in-__module_get.patch --]
[-- Type: text/plain, Size: 1143 bytes --]

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

From: Rusty Russell <rusty@rustcorp.com.au>

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@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

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

--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -387,7 +387,6 @@ 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();
}