From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 29900 invoked by alias); 13 Mar 2014 13:03:33 -0000 Mailing-List: contact gdb-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sourceware.org Received: (qmail 29872 invoked by uid 89); 13 Mar 2014 13:03:32 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,SPF_PASS autolearn=ham version=3.3.2 X-Spam-User: qpsmtpd, 2 recipients X-HELO: mail-pd0-f172.google.com Received: from mail-pd0-f172.google.com (HELO mail-pd0-f172.google.com) (209.85.192.172) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES128-SHA encrypted) ESMTPS; Thu, 13 Mar 2014 13:03:31 +0000 Received: by mail-pd0-f172.google.com with SMTP id p10so1043961pdj.31 for ; Thu, 13 Mar 2014 06:03:29 -0700 (PDT) X-Received: by 10.66.141.231 with SMTP id rr7mr2134870pab.41.1394715809692; Thu, 13 Mar 2014 06:03:29 -0700 (PDT) Received: from bubble.grove.modra.org ([101.166.26.37]) by mx.google.com with ESMTPSA id gj9sm6911397pbc.7.2014.03.13.06.03.27 for (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 13 Mar 2014 06:03:29 -0700 (PDT) Received: by bubble.grove.modra.org (Postfix, from userid 1000) id 15923EA00D2; Thu, 13 Mar 2014 23:33:23 +1030 (CST) Date: Thu, 13 Mar 2014 13:03:00 -0000 From: Alan Modra To: Mark Wielaard Cc: Cary Coutant , Doug Evans , "Metzger, Markus T" , "gdb@sourceware.org" , "binutils@sourceware.org" Subject: Re: vdso handling Message-ID: <20140313130322.GA3384@bubble.grove.modra.org> Mail-Followup-To: Mark Wielaard , Cary Coutant , Doug Evans , "Metzger, Markus T" , "gdb@sourceware.org" , "binutils@sourceware.org" References: <20140312071701.GW26922@bubble.grove.modra.org> <20140313010147.GZ26922@bubble.grove.modra.org> <1394704336.11818.115.camel@bordewijk.wildebeest.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1394704336.11818.115.camel@bordewijk.wildebeest.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-SW-Source: 2014-03/txt/msg00032.txt.bz2 On Thu, Mar 13, 2014 at 10:52:16AM +0100, Mark Wielaard wrote: > On Thu, 2014-03-13 at 11:31 +1030, Alan Modra wrote: > > It wouldn't > > help in the vdso case anyway, since the problem there is that you only > > have the loaded part of the original ELF file. > > Note that the vdso is often special, compared to other ELF dsos, because > the loaded part is just the complete ELF image in memory. Since they are > very simple they will just have one PT_LOAD at offset zero and if the > image is smaller than the page size then the whole file is just simply > mapped into memory completely. So by fetching the vdso ELF image from > remote memory you should be able to get the section headers and the > not-allocated sections too. Yes, but if the vdso does not fit in a page (which incidentally is inferred by program header p_align), then you may lose the section headers. I was assuming this was the case. -- Alan Modra Australia Development Lab, IBM