From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 1303 invoked by alias); 10 Feb 2006 19:00:35 -0000 Received: (qmail 1292 invoked by uid 22791); 10 Feb 2006 19:00:34 -0000 X-Spam-Check-By: sourceware.org Received: from ns.suse.de (HELO mx1.suse.de) (195.135.220.2) by sourceware.org (qpsmtpd/0.31) with ESMTP; Fri, 10 Feb 2006 19:00:31 +0000 Received: from Relay1.suse.de (mail2.suse.de [195.135.221.8]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.suse.de (Postfix) with ESMTP id 1B2C2F064; Fri, 10 Feb 2006 20:00:24 +0100 (CET) From: Andreas Schwab To: David Lecomber Cc: gdb Subject: Re: Whacky ia64: linux_proc_xfer_partial and lseek vs pread64 References: <1139591736.3780.26.camel@cpc2-oxfd8-0-0-cust771.oxfd.cable.ntl.com> <20060210181441.GA29255@nevyn.them.org> X-Yow: In order to make PLANS for the WEEKEND...so that we can read RESTAURANT REVIEWS and decide to GO to that restaurant & then NEVER GO...so we can meet a FRIEND after work in a BAR and COMPLAIN about Interior Sect'y JAMES WATT until the SUBJECT is changed to NUCLEAR BLACKMAIL...and so our RELATIVES can FORCE us to listen to HOCKEY STATISTICS while we wait for them to LEAVE on the 7:48.... Date: Fri, 10 Feb 2006 19:00:00 -0000 In-Reply-To: <20060210181441.GA29255@nevyn.them.org> (Daniel Jacobowitz's message of "Fri, 10 Feb 2006 13:14:41 -0500") Message-ID: User-Agent: Gnus/5.110003 (No Gnus v0.3) Emacs/22.0.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-IsSubscribed: yes Mailing-List: contact gdb-help@sourceware.org; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sourceware.org X-SW-Source: 2006-02/txt/msg00088.txt.bz2 Daniel Jacobowitz writes: > On Fri, Feb 10, 2006 at 07:04:51PM +0100, Andreas Schwab wrote: >> pread and lseek with SEEK_SET do not allow negative offsets. lseek on >> /proc/$$/mem is a special exception. > > Uh-oh. Should pread have the same exception, or must we fall back to > lseek? pread fails upfront with offset < 0, whereas lseek lets the filesystem llseek function decide. But a fallback wouldn't help here anyway, because you can't read the vdso memory with read, only with ptrace. Andreas. -- Andreas Schwab, SuSE Labs, schwab@suse.de SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany PGP key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different."