Re: [PATCH v4] livepatch/module: Correctly handle coming and going modules

Jiri Kosina
2015-03-16T19:15:48Z

On Thu, 12 Mar 2015, Petr Mladek wrote:

> There is a notifier that handles live patches for coming and going modules.
> It takes klp_mutex lock to avoid races with coming and going patches but
> it does not keep the lock all the time. Therefore the following races are
> possible:
[ ... snip ... ]
> diff --git a/include/linux/module.h b/include/linux/module.h
> index b653d7c0a05a..7232fde6a991 100644
> --- a/include/linux/module.h
> +++ b/include/linux/module.h
> @@ -344,6 +344,10 @@ struct module {
> unsigned long *ftrace_callsites;
> #endif
>
> +#ifdef CONFIG_LIVEPATCH
> + bool klp_alive;
> +#endif
> +

Rusty, are you okay with this please? I'd like to have the race fixed in
4.0 still, but don't want to be making changes to struct module without
your ack.

Thanks,

--
Jiri Kosina
SUSE Labs