From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1KxQBO-0001rZ-Rq for qemu-devel@nongnu.org; Tue, 04 Nov 2008 12:59:14 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1KxQBK-0001r3-5e for qemu-devel@nongnu.org; Tue, 04 Nov 2008 12:59:14 -0500 Received: from [199.232.76.173] (port=36138 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1KxQBJ-0001r0-VE for qemu-devel@nongnu.org; Tue, 04 Nov 2008 12:59:09 -0500 Received: from gecko.sbs.de ([194.138.37.40]:17128) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1KxQBJ-000081-Q4 for qemu-devel@nongnu.org; Tue, 04 Nov 2008 12:59:10 -0500 Message-ID: <49108D03.4000204@siemens.com> Date: Tue, 04 Nov 2008 18:57:23 +0100 From: Jan Kiszka MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH] gdbstub: x86-64: reintroduce dynamic register sets References: <491084F7.2050800@siemens.com> <200811041742.58859.paul@codesourcery.com> In-Reply-To: <200811041742.58859.paul@codesourcery.com> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paul Brook Cc: qemu-devel@nongnu.org Paul Brook wrote: > On Tuesday 04 November 2008, Jan Kiszka wrote: >> Commit 5459 broke the dynamic register set switching of qemu's gdbstub >> for x86-64. This prevents setting the correct architecture in gdb when >> debugging 32 or 16-bit code in a 64-bit emulator. Fix this. > > Is this really a feature? Surely any attached gdb is going to break horribly > when we transition from a 64-bit to a 32-bit code segment. Well, it would be real feature if gdb was smart enough to track those switches automatically... However, you can (and obviously have to) call "set arch ..." after that switch in order to get the proper disassembly. Or you happen to use qemu-system-x86_64 with a 32-bit guest and fire up gdb with the appropriate 32-bit binary directly. Both used to work fine. But if there is a way to tell gdb to switch x86 archs without switching the remote gdb packet length for register queries, I would happily use that and drop my patch! Jan -- Siemens AG, Corporate Technology, CT SE 2 ES-OS Corporate Competence Center Embedded Linux