Re: [PATCH v2 11/12] ARM: wire up UEFI init and runtime support

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

 



On Mon, Nov 16, 2015 at 08:04:00PM +0100, Ard Biesheuvel wrote:
> OK. So you mean set TTBR to the zero page, perform the TLB flush and
> only then switch to the new page tables?

Not quite.

If you have global mappings below TASK_SIZE, you would need this
sequence when switching either to or from the UEFI page tables:

- switch to another set of page tables which only map kernel space
  with nothing at all in userspace.
- flush the TLB.
- switch to your target page tables.

As I say in response to one of your other patches, it's probably
much easier to avoid any global mappings below TASK_SIZE.

-- 
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.
--
To unsubscribe from this list: send the line "unsubscribe linux-efi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Security]     [Bugtraq]     [Linux OMAP]     [Linux MIPS]     [ECOS]     [Asterisk Internet PBX]     [Linux API]

  Powered by Linux