Re: [PATCH] x86: Use entire page for the per-cpu GDT only if paravirt-enabled

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue, Sep 29, 2015 at 1:35 PM, Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote:
>
> Does anyone know what happens if you stick a non-accessed segment in
> the GDT, map the GDT RO, and access it?

You should get a #PF, as you guess, but go ahead and test it if you
want to make sure.

We do something very similar for the old Pentium F0 0F bug - we mark
the IDT read-only, which causes the (bogus) locked read of the IDT
entry that the F00F bug resulted in to be caught as a page fault
instead.

              Linus
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux