Re: Linux 2.4.1-ac15

[Keith Owens]

On Mon, 19 Feb 2001 11:35:08 +0000 (GMT), 
Alan Cox <[e-mail]> 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.