linux-kernel - Re: [PATCH REPOST for 2.6.25] Use an own random generator for pageattr-test.c

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]

Message-ID: <20080311104531.GB18917@one.firstfloor.org>
Date:	Tue, 11 Mar 2008 11:45:31 +0100
From:	Andi Kleen <andi@...stfloor.org>
To:	Thomas Gleixner <tglx@...utronix.de>
Cc:	Andi Kleen <andi@...stfloor.org>, Ingo Molnar <mingo@...e.hu>,
	linux-kernel@...r.kernel.org, akpm@...l.org
Subject: Re: [PATCH REPOST for 2.6.25] Use an own random generator for pageattr-test.c

On Tue, Mar 11, 2008 at 09:25:21AM +0100, Thomas Gleixner wrote:
> On Tue, 11 Mar 2008, Andi Kleen wrote:
> > Use an own random generator for pageattr-test.c
> > 
> > [Repost. Please ack/nack. This is a bug fix and imho a .25 late merge 
> > candidate because it fixes a subtle bug]
> 
> Care to point out which "subtle bug" is fixed ? 
> 
> You replace a random generator by another to get repeateable
> sequences. The non repeatability of the cpa test patterns is hardly a
> "subtle bug".

The subtle bug(s) are first that it is not repeatable (it really should),
then that it only initializes the CPU where the code first runs
(since srandom32 is per CPU) and later might change CPUs and then that it 
adds totally unnecessary state bits to CPU #0 (or whatever runs first).

-Andii

--
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/