linux-kernel - Re: atomics: document that linux expects certain atomic behaviour from unsigned long

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: <20090103205628.GE1666@elf.ucw.cz>
Date:	Sat, 3 Jan 2009 21:56:29 +0100
From:	Pavel Machek <pavel@...e.cz>
To:	Alan Cox <alan@...rguk.ukuu.org.uk>
Cc:	kernel list <linux-kernel@...r.kernel.org>,
	Andrew Morton <akpm@...l.org>, mtk.manpages@...il.com,
	rdunlap@...otime.net, linux-doc@...r.kernel.org
Subject: Re: atomics: document that linux expects certain atomic behaviour
	from unsigned long

On Sat 2009-01-03 20:30:44, Alan Cox wrote:
> > If it is okay and linux relies on it, it should be documented.
> > 
> > If it is not okay, I guess we should document it, too -- it seems to
> > be common mistake. 
> 
> A lot of old code did it knowing it was under the BKL, outside of the BKL
> its a very bad idea. There were lots of them in the tty layer and I don't
> doubt there are some left I missed too 8(

I have seen this in new code (some LED driver last time), definitely
no BKL.

Is there concrete architecture where it breaks? I'd expect i386/x86-64
to be safe, and pretty much everyone to be safe as long as that long
is aligned.... or that was the result of arch-maintainers
discussion...

I'd really like to document if it is right or not, so that I can point
people to documentation...
								Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
--
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/