Messages in this thread | | | Date | Tue, 31 May 2011 19:51:22 +0100 | From | Matthew Garrett <> | Subject | Re: [RFC][PATCH] Randomize kernel base address on boot |
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On Tue, May 31, 2011 at 11:40:13AM -0700, H. Peter Anvin wrote: > On 05/31/2011 09:52 AM, Matthew Garrett wrote: > > The BIOS E820 map, or the kernel representation? In either case, this > > isn't going to work well with EFI. There are regions that will be marked > > as available in the E820 map that we *mustn't* touch until we've entered > > EFI virtual mode. > > > > (This is, clearly, insane). > > > > I believe we could (should!) mark them reserved, not available, in the > E820 map and free them later.
That was my original approach, but it requires that the bootloader be modified and it turns out that it's a lot harder to hand reserved regions back to the OS than it is to just reserve it in-kernel. The complete inflexibility of e820 is massively unhelpful here. It's just not possible to represent all of the EFI memory map data in it.
-- Matthew Garrett | mjg59@srcf.ucam.org
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