From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx150.postini.com [74.125.245.150]) by kanga.kvack.org (Postfix) with SMTP id 347B26B0068 for ; Thu, 22 Dec 2011 10:52:42 -0500 (EST) Received: by iacb35 with SMTP id b35so15491804iac.14 for ; Thu, 22 Dec 2011 07:52:41 -0800 (PST) Message-ID: <4EF35243.9030600@gmail.com> Date: Thu, 22 Dec 2011 23:52:35 +0800 From: "nai.xia" MIME-Version: 1.0 Subject: Re: Question about missing "cld" in x86 string assembly code References: <201112172258.24221.nai.xia@gmail.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: Linus Torvalds Cc: Brian Gerst , Andi Kleen , Linux-MM , LKML On 2011a1'12ae??18ae?JPY 02:39, Linus Torvalds wrote: > On Sat, Dec 17, 2011 at 9:08 AM, Brian Gerst wrote: >> >> The i386 ELF ABI states "The direction flag must be set to the >> a??a??forwarda??a?? (that is, zero) direction before entry and upon exit from >> a function." Therefore it can be assumed to be clear, unless >> explicitly set. > > The exception, of course, being bootup, fault and interrupt handlers, > and after we've called out to foreign code (ie BIOS). Yeah, I think I see these cld's now. Thanks for the answers! Nai > > So there *are* a few cld's sprinkled around, they are just fairly rare. > > Linus -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org