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 PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Fri, 07 Dec 2007 20:25:28 +0100 From: Rene Herman <rene.herman@...access.nl> To: Alan Cox <alan@...rguk.ukuu.org.uk> CC: Andi Kleen <andi@...stfloor.org>, "David P. Reed" <dpreed@...d.com>, linux-kernel@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>, "H. Peter Anvin" <hpa@...or.com> Subject: Re: RFC: outb 0x80 in inb_p, outb_p harmful on some modern AMD64 with MCP51 laptops On 07-12-07 19:42, Alan Cox wrote: > On Fri, 07 Dec 2007 19:45:25 +0100 > Rene Herman <rene.herman@...access.nl> wrote: > >> On 07-12-07 18:19, Alan Cox wrote: >> >>> On Fri, 7 Dec 2007 17:31:16 +0100 >>> Andi Kleen <andi@...stfloor.org> wrote: >>> >>>>> You don't need to. Port 0x80 historically is about 8uS so just udelay(8) >>>>> and make sure the initial default delay is conservative enough before the >>>> How would you make it conservative enough handling let's say a 6Ghz CPU >>>> that can execute multiple jumps per cycle? >>> Pick a sane worst case and go with it at boot. We don't have to be >>> accurate before we tune udelay - over long in uSecs isnt going to hurt, >>> and most post boot _p's can be replaced by udelay(8) now >> Isn't 8 generally a bit overly long? I believe the norm is 1? > > 8uS is an ISA bus transaction. You very likely know better but just in case you're confused -- I thought it was 8 cycles... Rene. -- 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/
Powered by blists - more mailing lists