linux-kernel - Re: BGRT Pointer in System RAM

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: <CAOULuOYySYf=Qv973Wx+DZMYKok8uu=Nosw7-3ajNvcrNEspPA@mail.gmail.com>
Date:	Mon, 15 Jul 2013 20:00:39 -0400
From:	Parag Warudkar <parag.lkml@...il.com>
To:	Josh Triplett <josh@...htriplett.org>
Cc:	Andy Lutomirski <luto@...capital.net>,
	LKML <linux-kernel@...r.kernel.org>, linux-acpi@...r.kernel.org
Subject: Re: BGRT Pointer in System RAM

On Mon, Jul 15, 2013 at 7:56 PM, Parag Warudkar <parag.lkml@...il.com> wrote:
> On Mon, Jul 15, 2013 at 7:04 PM, Josh Triplett <josh@...htriplett.org> wrote:
>
>> We do need to handle the case of a valid pointer into memory that e820
>> calls system RAM, as well as the case of a valid pointer into memory
>> reserved for the BIOS or similar, but not the case of an invalid
>> pointer.
>
> Would that be as simple as
>
>                      page_is_ram(

Damn shortcuts -
                        virt_addr = phys_to_virt(image->base_address);
                        if(page_is_ram(virt_to_page(virt_addr))) {
                            //direct read from virt addr
                        }

Would that suffice for the System RAM case or some other MM trickery
is involved?

Thanks,
Parag
--
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/