From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 5214 invoked by alias); 10 May 2003 17:24:41 -0000 Mailing-List: contact gdb-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sources.redhat.com Received: (qmail 5189 invoked from network); 10 May 2003 17:24:40 -0000 Received: from unknown (HELO localhost.redhat.com) (24.157.166.107) by sources.redhat.com with SMTP; 10 May 2003 17:24:40 -0000 Received: from redhat.com (localhost [127.0.0.1]) by localhost.redhat.com (Postfix) with ESMTP id 946392B4E; Sat, 10 May 2003 13:24:39 -0400 (EDT) Message-ID: <3EBD35D7.2030207@redhat.com> Date: Sat, 10 May 2003 17:24:00 -0000 From: Andrew Cagney User-Agent: Mozilla/5.0 (X11; U; NetBSD macppc; en-US; rv:1.0.2) Gecko/20030223 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Roland McGrath Cc: Mark Kettenis , gdb@sources.redhat.com Subject: Re: gdb support for Linux vsyscall DSO References: <200305100707.h4A777T29932@magilla.sf.frob.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-SW-Source: 2003-05/txt/msg00184.txt.bz2 Roland, How exactly does this vsyscall memory region(1) come to be? For instance, how does GLIBC come to know where it is - GLIBC would need the region's address to perform a syscall to find the regions address. If the underlying mechanism is explained (this is far from a tranditional lib*.so), GDB developers will be in a better position to judge the best way of handling this. Is there, for instance, anything to prevent GDB locating the symbol (in GLIBC) that points at the vsyscall area and then using that? Similar for any mapped in eh_frame region. Assuming that GDB has a well defined trigger point for knowing when the symbol can be referenced - but GDB would need that anyway. This would eliminate the need to store all this elf header stuff in the Kernel, let GDB confine any changes to a single linux-tdep.c file, and even work remotely or with a core file. However, before anyone tries to run with such ideas, what's really going on? enjoy, Andrew