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]

Date:	Thu, 18 Apr 2013 13:13:35 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Darren Hart <darren.hart@...el.com>
CC:	Matthew Garrett <matthew.garrett@...ula.com>,
	Matt Fleming <matt@...sole-pimps.org>,
	Josh Triplett <josh@...htriplett.org>,
	"Bryan O'Donoghue" <bryan.odonoghue.lkml@...us-software.ie>,
	"linux-efi@...r.kernel.org" <linux-efi@...r.kernel.org>,
	"x86@...nel.org" <x86@...nel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	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 01:11 PM, Darren Hart wrote:
>>
>> I would expect that if there are any 32-bit UEFI systems that ship with
>> BGRT support (and Darren makes it sound like that's a possibility),
>> there's a realistic chance of the BGRT ending up allocated above the
>> highmem barrier.
> 
> I can certainly ensure we sit below that barrier on the MinnowBoard. We
> can also speak with the Intel UEFI firmware development teams to see
> about making that a requirement. I don't know if we'll be successful,
> but Matt, Peter, and I have recently coaxed some changes of that nature in.
> 

No, that is the wrong approach.  The HIGHMEM barrier is a Linux kernel
construct and isn't even guaranteed to be the same from one boot *of the
same kernel* to another.  The value 896M is merely the default, but it
can be affected by both compile time and command line options.

	-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/