linux-kernel - Re: [PATCH 6/8] i386: bitops: Don't mark memory as clobbered unnecessarily

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: <alpine.LFD.0.999.0707241444040.3607@woody.linux-foundation.org>
Date:	Tue, 24 Jul 2007 14:46:01 -0700 (PDT)
From:	Linus Torvalds <torvalds@...ux-foundation.org>
To:	Jeremy Fitzhardinge <jeremy@...p.org>
cc:	Andi Kleen <andi@...stfloor.org>,
	Trent Piepho <xyzzy@...akeasy.org>,
	Nick Piggin <nickpiggin@...oo.com.au>,
	Satyam Sharma <ssatyam@....iitk.ac.in>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	David Howells <dhowells@...hat.com>,
	Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: [PATCH 6/8] i386: bitops: Don't mark memory as clobbered
 unnecessarily



On Tue, 24 Jul 2007, Jeremy Fitzhardinge wrote:
> >
> > But gcc docs also talk about the other things volatile means, including 
> > "not significantly moved".
> 
> Actually, it doesn't.  In fact it goes out of its way to say that "asm
> volatile" statements can be moved quite a bit, with respect to other
> asms, other code, jumps, basic blocks, etc.

Ahh. That's newer.

Historically, gcc manuals used to say "may not be deleted or significantly 
reordered".

So they've weakened what it means, probably exactly because it wasn't 
well-defined before either.

		Linus
-
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/