linux-kernel - Re: [PATCH] romsignature/checksum cleanup

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 for Android: free password hash cracker in your pocket

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

Date:	Sat, 06 Jan 2007 04:46:10 +0100
From:	Rene Herman <rene.herman@...il.com>
To:	Jeremy Fitzhardinge <jeremy@...p.org>
CC:	Zachary Amsden <zach@...are.com>,
	Rusty Russell <rusty@...tcorp.com.au>,
	Andrew Morton <akpm@...l.org>,
	Linux Kernel <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] romsignature/checksum cleanup

Jeremy Fitzhardinge wrote:

> Well, in the Xen case, where the pages are simply not mapped, then
> the signature simply won't exist.  In other cases, I guess its
> possible the signature might exist but the rest of the ROM doesn't,
> but that won't happen on normal hardware.

In your opinion, is the attached (versus 2.6.20-rc3) better? This uses 
probe_kernel_address() for all accesses. Or rather, an expanded version 
thereof. The set_fs() and pagefault_{disable,enable} calls are only done 
once in probe_roms().

Accessing the length byte at rom[2] with __get_user() is overkill after 
just checking the signature at 0 and 1 but direcly accessing only that 
makes for inconsistent code IMO. It's only a .fixup entry...

I can't say I'm all that sure that that pagefault_disable() call is 
still applicable now that it got expanded into the probe_roms() stage?

Rene.

View attachment "probe_kernel_address.diff" of type "text/plain" (2543 bytes)