linux-kernel - Re: [PATCH] Remove warning in efi_enter_virtual

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <5170216C.9020300@zytor.com>
Date:	Thu, 18 Apr 2013 09:38:04 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Josh Triplett <josh@...htriplett.org>
CC:	Matt Fleming <matt@...sole-pimps.org>,
	"Bryan O'Donoghue" <bryan.odonoghue.lkml@...us-software.ie>,
	matthew.garrett@...ula.com, linux-efi@...r.kernel.org,
	x86@...nel.org, linux-kernel@...r.kernel.org,
	Darren Hart <darren.hart@...el.com>,
	Ingo Molnar <mingo@...nel.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Josh Boyer <jwboyer@...hat.com>
Subject: Re: [PATCH] Remove warning in efi_enter_virtual_mode

On 04/18/2013 09:33 AM, Josh Triplett wrote:
> On Thu, Apr 18, 2013 at 12:00:26PM +0100, Matt Fleming wrote:
>>> No, no - we *don't* have a BGRT object at all.
>>>
>>> We have a completely clean memory map - but the BGRT code is causing the
>>> is_ram() failure.
>>  
>> You assume that mapping of the Boot Services regions is done purely for
>> the benefit of pulling out the bgrt image - it's not, see the above
>> commit log - and I assumed that you had an ACPI bgrt pointer in your
>> memory map, but you don't.
>>
>> Darren, Josh, have you ever seen an i386 machine with a bgrt pointer? If
>> not, and given that we've never seen an i386 firmware that requires the
>> above workaround from Matthew, combined with the fact that there are so
>> few i386 implementations out there, I'm inclined to apply the patch
>> below, because anything else is a lot more work. We can address this
>> properly if we ever start seeing i386 machines with bgrt pointers that
>> reference highmem.
> 
> The machine I developed the BGRT changes on kept the image below the 4G
> mark, inside one of the memory regions reclaimable via
> ExitBootServices().
> 

Well, highmem is >= ~896M.  Do you have a machine with BGRT over the
highmem mark?

	-hpa


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/