Re: BUG in x86 do_page_fault? [was Re: in_atomic doesn't count local_irq_disable?]

From: Pavel Machek
Date: Sun Jan 04 2004 - 09:58:12 EST


Hi!

> > in_atomic() doesn't seem to return true
> > in code sections where IRQ's have been disabled (using
> > local_irq_disable).
> >
> > As a result, I think do_page_fault() on x86 needs to
> > be updated to note this fact:
>
> NO.
>
> Please don't do this, it will result in some _really_ nasty problems with
> X and other programs that potentially disable interrupts in user
> space.

If user program causes page fault with interrupts disabled, it is
certainly buggy, right?

Either the user program does not really need irq disabled or it does
need that but page fault just broke its guarantees (=> severe problems
ahead).

In both cases there's user program that needs fixing.
Pavel
--
When do you have a heart between your knees?
[Johanka's followup: and *two* hearts?]
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/