linux-kernel - Re: [PATCH] powerpc 8xx: Loading kernels over 8Mbytes without CONFIG_PIN

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:	Sat, 07 Dec 2013 10:39:48 +0100
From:	christophe leroy <christophe.leroy@....fr>
To:	Scott Wood <scottwood@...escale.com>
CC:	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	Paul Mackerras <paulus@...ba.org>,
	linux-kernel@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org
Subject: Re: [PATCH] powerpc 8xx: Loading kernels over 8Mbytes without CONFIG_PIN_TLB


Le 06/12/2013 20:09, Scott Wood a écrit :
> On Wed, 2013-11-27 at 12:04 +0100, Christophe Leroy wrote:
>> Today, the only way to load kernels whose size is greater than 8Mbytes is to
>> activate CONFIG_PIN_TLB. Otherwise, the physical memory initially mapped is
>> limited to 8Mbytes. This patch sets up 24 Mbytes of initial memory regardless
>> of whether CONFIG_PIN_TLB is active or not. It allows to load "big" kernels
>> (for instance when activating CONFIG_LOCKDEP_SUPPORT) without having
>> to activate CONFIG_PIN_TLB.
> So, what happens on boards with less than 24M memory present?  Even if
> you avoid explicitly referencing those addresses, what if there is a
> speculative access -- or does 8xx not do that?
>
> -Scott
>

Function setup_initial_memory_limit() in mm/init_32.c defines the limits 
based on the parameters given by the bootloader.
As far as I know, the 8xx doesn't do speculative access just because an 
area is loaded in a TLB Entry.

Christophe

---
Ce courrier électronique ne contient aucun virus ou logiciel malveillant parce que la protection avast! Antivirus est active.
http://www.avast.com

--
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/