Messages in this thread | | | Date | Thu, 6 Feb 2020 13:32:48 -0800 | From | Kees Cook <> | Subject | Re: [RFC PATCH 11/11] x86/boot: Move "boot heap" out of .bss |
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On Thu, Feb 06, 2020 at 09:25:59AM -0500, Arvind Sankar wrote: > On Thu, Feb 06, 2020 at 03:13:12AM -0800, Kees Cook wrote: > > Yes, thank you for the reminder. I couldn't find the ZO_INIT_SIZE when I > > was staring at this, since I only looked around the compressed/ directory. > > :) > > > > There's another thing I noticed -- you would need to ensure that the > init_size in the header covers your boot heap even if you did split it > out. The reason is that the bootloader will only know to reserve enough > memory for init_size: it's possible it might put the initrd or something > else following the kernel, or theoretically there might be reserved > memory regions or the end of physical RAM immediately following, so you > can't assume that area will be available when you get to extract_kernel.
Yeah, that's what I was worrying about after I wrote that patch. Yours is the correct solution. :) (I Acked both of those now).
-- Kees Cook
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