Re: Linux 2.4.1-ac15

From: Keith Owens (kaos@ocs.com.au)
Date: Mon Feb 19 2001 - 06:54:39 EST


On Mon, 19 Feb 2001 11:35:08 +0000 (GMT),
Alan Cox <alan@lxorguk.ukuu.org.uk> wrote:
>The problem isnt running module code. What happens in this case
>
> mod->next = module_list;
> module_list = mod; /* link it in */
>
>Note no write barrier.

<humour>It works on ix86 so the code must be right</humour>

>Delete is even worse
>
>We unlink the module
>We free the memory
>
>At the same time another cpu may be walking the exception table that we free.

Another good reason why locking modules via use counts from external
code is not the right fix. We definitely need a quiesce model for
module removal.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Fri Feb 23 2001 - 21:00:19 EST