linux-kernel - Re: [RFC patch 0/4] TSC calibration improvements

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, 6 Sep 2008 14:10:32 -0700 (PDT)
From:	Linus Torvalds <torvalds@...ux-foundation.org>
To:	Thomas Gleixner <tglx@...utronix.de>
cc:	Alok Kataria <akataria@...are.com>,
	Alan Cox <alan@...rguk.ukuu.org.uk>,
	LKML <linux-kernel@...r.kernel.org>,
	Arjan van de Veen <arjan@...radead.org>,
	"H. Peter Anvin" <hpa@...or.com>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Dan Hecht <dhecht@...are.com>,
	Garrett Smith <garrett@...are.com>
Subject: Re: [RFC patch 0/4] TSC calibration improvements



On Sat, 6 Sep 2008, Thomas Gleixner wrote:
>  
> Where is a guarantee, that excpect is not decremented before we break
> out of the loop ? 

Quite the reverse. We have a guarantee that it _is_ decremented.

Adn that guarantee is very much about the C language.

		for (a ; b ; c) {
			..
		}

translates as

		a;
		while (b) {
			..
	continue:
			c;
		}

And this has absolutely _nothing_ to do with any gcc oddity or anything 
else. 

The fact is, the code that Ingo added was totally bogus. The real bug was 
that he did a totally bogus "--expect" in the argument to that last call. 

Because 'c' *will* have been done after the last iteration of the loop.

			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/