[kernel-hardening] Re: [PATCH] shm: fix a race between shm_exit() and shm_init()

Linus Torvalds
2011-08-04T01:01:05Z

On Wed, Aug 3, 2011 at 2:50 PM, Andrew Morton <akpm@linux-foundation.org> wrote:
>
> Well, it's still a workaround.  We'll still have driver_init() trying
> to run userspace helpers at an inappropriate time, and failing to do
> so.  Either something will break or it should not be attempting
> attempting to do this at all.

Well, it has never worked before either, so I wouldn't call it a
"workaround", more of a "insane subsystems do user-mode helpers for
crazy small things, and at crazy times. Stop them from wasting our
time and effort at those crazy times when we know they would fail
anyway".

> Perhaps Kay and Greg can suggest how we can fix all this up?

I think just not calling user-mode when user-mode isn't ready is a real fix.

The fact that the device models send an absolutely *insane* amount of
events for everything, and don't track "this is the bootup device
scan" on their own is kind of sad, but it's how they roll. This fixes
it at a core level, so that the device layer doesn't have to track the
"am I booting, or is this a dynamic event?" at all.

Linus