Commit 7f9a50a5 authored Feb 07, 2009 by Rusty Russell Committed by Linus Torvalds Feb 07, 2009

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>

parent f12b12a8

include/linux/module.h

+0 −1

Original line number	Diff line number	Diff line
		@@ -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();
		}

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