Re: [patch 0/9] x86, xsave: xsave/xrstor support

From: Ingo Molnar
Date: Thu Jul 31 2008 - 18:52:22 EST



* Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:

> > But thats not what I see with for ex with, w83627hf_wdt.c
> >
> > Its done at the module_init time. (while I thought it should be
> > really done when some user level app opens the device, probably its
> > poorly written to take care if the kernel panics before starting
> > userland. but kernel can even die before the watchdog driver load
> > aswell ;-)
>
> Yeah, that's a _really_ broken watchdog timer driver. There's no way
> that it's correct to start the watchdog at init time, at least when
> compiled in.
>
> It also looks to me like it's not even probing for the hardware - it's
> just assuming it's there. That's scary. Am I missing something?
>
> It really shouldn't be activated until it's opened. And it really
> shouldn't just write to ports randomly without checking that they make
> sense...

there are a handful of old ISA-ish drivers that can crash randconfig
kernels in various ways. [indefinite lockups, crashes, stomped-over
hardware, non-working keyboard, etc.]

I mapped most of them out via many months of trial-and-error - but it
would still be nice to have some separate config option to disable the
known ones. CONFIG_ALLOW_NON_GENERIC or something like that - which i
would unset in the randconfig runs.

( They are not CONFIG_BROKEN per se, because often it's hardware that
cannot be probed in any reliable way - the driver just assumes it's
there. )

Ingo
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