Re: [RFC PATCH] x86: Config options to assign versions in the PE-COFF header

From: hpa
Date: Fri Apr 14 2017 - 01:22:47 EST


On April 13, 2017 8:51:19 PM PDT, Gary Lin <glin@xxxxxxxx> wrote:
>On Thu, Apr 13, 2017 at 03:21:20PM -0700, hpa@xxxxxxxxx wrote:
>> On April 11, 2017 3:20:41 AM PDT, Gary Lin <glin@xxxxxxxx> wrote:
>> >This commit adds the new config options to allow the user to modify
>the
>> >following fields in the PE-COFF header.
>> >
>> >UINT16 MajorOperatingSystemVersion
>> >UINT16 MinorOperatingSystemVersion
>> >UINT16 MajorImageVersion
>> >UINT16 MinorImageVersion
>> >
>> >Those fields are mainly for the executables or libraries in Windows
>NT
>> >or higher to specify the minimum supported Windows version and the
>> >version of the image itself.
>> >
>> >Given the fact that those fields are ignored in UEFI, we can safely
>> >reuse
>> >those fields for other purposes, e.g. Security Version(*).
>> >
>> >(*) https://github.com/lcp/shim/wiki/Security-Version
>> >
>> >Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
>> >Cc: Ingo Molnar <mingo@xxxxxxxxxx>
>> >Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
>> >Cc: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
>> >Cc: Michal Marek <mmarek@xxxxxxxx>
>> >Cc: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx>
>> >Cc: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
>> >Cc: Joey Lee <jlee@xxxxxxxx>
>> >Cc: Vojtech Pavlik <vojtech@xxxxxxx>
>> >Signed-off-by: Gary Lin <glin@xxxxxxxx>
>> >Tested-by: Joey Lee <jlee@xxxxxxxx>
>> >---
>[snip]
>>
>> Reusing PECOFF fields seems doubleplusunsafe: we don't own those
>fields, the UEFI forum does. It would make a lot more sense to add
>these fields to the bzImage header directly or indirectly (via a
>pointer), the latter would be more economical since the bzImage header
>size is bounded.
>>
>> We could even define it as a pointer to a "security information
>header" with its own size field, so it can be grown in the future as
>needed.
>Reusing PE-COFF simplifies the implementation since shim can parse the
>header directly. I can raise the issue to the UEFI forum to clarify the
>usage of those fields.
>
>Meanwhile, I'll also look into the bzImage header in case the PE-COFF
>header is really a NO-GO.
>
>Thanks,
>
>Gary Lin

If we are going to use the PE-COFF hear then you need to write a proposal and get the UEFI forum to sign off on it.
--
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