Re: [stable] [PATCH] x86: Reserve FIRST_DEVICE_VECTOR in used_vectors bitmap

[Greg KH <greg@kroah.com>]

On Fri, Oct 10, 2008 at 04:36:11PM -0400, Stefan Bader wrote:
> Greg KH wrote:
> > On Fri, Oct 10, 2008 at 10:23:50PM +0200, Ingo Molnar wrote:
> >> * Greg KH <greg@kroah.com> wrote:
> >>
> >>> On Fri, Oct 10, 2008 at 04:01:54PM -0400, Stefan Bader wrote:
> >>>> Affected: 2.6.24-2.6.27
> >>>>
> >>>> Someone from the community found out, that after repeatedly unloading and
> >>>> loading a device driver that uses MSI IRQs, the system eventually assigned
> >>>> the vector initially reserved for IRQ0 to the device driver.
> >>>>
> >>>> The reason for this is, that although IRQ0 is tied to the FIRST_DEVICE_VECTOR
> >>>> when declaring the irq_vector table, the corresponding bit in the used_vectors
> >>>> map is not set. So, if vectors are released and assigned often enough, the
> >>>> vector will get assigned to another interrupt. This happens more often with
> >>>> MSI interrupts as those are exclusively using a vector.
> >>>>
> >>>> Fix this by setting the bit for the FIRST_DEVICE_VECTOR in the bitmap.
> >>>>
> >>>> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
> >>> Hint, if you want patches to go into the -stable tree, just add:
> >>> 	cc: Stable <stable@kernel.org>
> >>> to the patch when you submit it in the signed-off-by area, and it will
> >>> be automatically sent to us when it goes into the main kernel tree.
> >> yes. Note that this is a special case, as there will be no upstream 
> >> commit to tag with Cc: <stable@kernel.org>, because this bug got 
> >> eliminated via not backportable means: APIC code unification.
> >>
> >> Acked-by: Ingo Molnar <mingo@elte.hu>
> > 
> > So this is a -stable release only patch?  .28 will never get/need this?
> > 
> > thanks,
> > 
> > greg k-h
> 
> Correct. Tried to hint this by the Affected line but should have been more verbose.

Great, thanks for letting me know, I'll queue it up for -stable.

Oh, next time, please don't attach patches in base64 format, that's a
pain in the ass...

thanks,

greg k-h