From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 14799 invoked by alias); 1 Jun 2012 14:08:42 -0000 Received: (qmail 14782 invoked by uid 22791); 1 Jun 2012 14:08:41 -0000 X-SWARE-Spam-Status: No, hits=-7.5 required=5.0 tests=AWL,BAYES_00,KHOP_RCVD_UNTRUST,KHOP_THREADED,RCVD_IN_DNSWL_HI,RCVD_IN_HOSTKARMA_W,SPF_HELO_PASS,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Fri, 01 Jun 2012 14:08:25 +0000 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q51E8PTR018338 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Fri, 1 Jun 2012 10:08:25 -0400 Received: from [127.0.0.1] (ovpn01.gateway.prod.ext.ams2.redhat.com [10.39.146.11]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id q51E8N9o022725; Fri, 1 Jun 2012 10:08:24 -0400 Message-ID: <4FC8CCD7.9060800@redhat.com> Date: Fri, 01 Jun 2012 14:08:00 -0000 From: Pedro Alves User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20120430 Thunderbird/12.0.1 MIME-Version: 1.0 To: Joakim Tjernlund CC: gdb-patches@sourceware.org Subject: Re: [PATCH] remote: Avoid unwanted shlib internal BPs When debugging Linux kernel or u-boot with Abatron BDI emulator an error occurs: References: <1338557804-20910-1-git-send-email-Joakim.Tjernlund@transmode.se> In-Reply-To: <1338557804-20910-1-git-send-email-Joakim.Tjernlund@transmode.se> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2012-06/txt/msg00010.txt.bz2 On 06/01/2012 02:36 PM, Joakim Tjernlund wrote: > .. > (gdb) tar remote bdi:2001 > Remote debugging using bdi:2001 > 0xeff80050 in ?? () > (gdb) mon reset > (gdb) cont > Continuing. > Warning: > Cannot insert breakpoint -1. > Error accessing memory address 0xc0000000: Unknown error 4294967295. > > (gdb) maintenance info breakpoints > Num Type Disp Enb Address What > -1 shlib events keep y 0xc0000000 <_stext> inf 1 > > gdb mistakenly inserts a special shared library BP even though > there area no such libs in either linux or u-boot. GDB has no special knowledge of the Linux kernel, nor of u-boot. A GNU/Linux targeted GDB (*-*-linux-gnu) recognizes, and knows how to debug user space applications. If the kernel binary or the u-boot binary look very much like GNU/Linux user space programs, the *-*-linux-gnu targeted GDB will assume that's what they are. If you used a bare metal elf/eabi targeted GDB, which is really what those programs are, you'd not see this. > Fix this by explicitly informing remote_add_inferior() that > the remote is attached. NAK. This is not a "fix", it's papering over the problem, and regresses GDB. It makes GDB always detach on quit, instead of asking the remote end whether it is "attached" or whether it has "spawned" the inferior. -- Pedro Alves