Re: [RFC PATCH 1/2] module: Ensure a module's state is set accordingly during module coming cleanup code

From: Rusty Russell
Date: Tue Oct 25 2016 - 21:34:58 EST


Aaron Tomlin <atomlin@xxxxxxxxxx> writes:
> In load_module() in the event of an error, for e.g. unknown module
> parameter(s) specified we go to perform some module coming clean up
> operations. At this point the module is still in a "formed" state
> when it is actually going away.
>
> This patch updates the module's state accordingly to ensure anyone on the
> module_notify_list waiting for a module going away notification will be
> notified accordingly.

I recall a similar proposal before.

I've audited all the subscribers to check they didn't look at
mod->state; they seem OK.

We actually do this in the init-failed path, so this should be OK.

Acked-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>

Thanks,
Rusty.

> Signed-off-by: Aaron Tomlin <atomlin@xxxxxxxxxx>
> ---
> kernel/module.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/kernel/module.c b/kernel/module.c
> index f57dd63..ff93ab8 100644
> --- a/kernel/module.c
> +++ b/kernel/module.c
> @@ -3708,6 +3708,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
> sysfs_cleanup:
> mod_sysfs_teardown(mod);
> coming_cleanup:
> + mod->state = MODULE_STATE_GOING;
> blocking_notifier_call_chain(&module_notify_list,
> MODULE_STATE_GOING, mod);
> klp_module_going(mod);
> --
> 2.5.5