From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:53255) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gwTxH-00035Y-56 for qemu-devel@nongnu.org; Wed, 20 Feb 2019 10:38:41 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gwTxD-0006xK-A4 for qemu-devel@nongnu.org; Wed, 20 Feb 2019 10:38:37 -0500 Received: from mail-wm1-f65.google.com ([209.85.128.65]:52976) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1gwTx9-0006sY-CY for qemu-devel@nongnu.org; Wed, 20 Feb 2019 10:38:33 -0500 Received: by mail-wm1-f65.google.com with SMTP id m1so7157531wml.2 for ; Wed, 20 Feb 2019 07:38:15 -0800 (PST) References: <251451940.431966.1548259107629.ref@mail.yahoo.com> <251451940.431966.1548259107629@mail.yahoo.com> <20190123180804.GA1040@flamenco> <70145779.391347.1548334794441@mail.yahoo.com> <87va2eyy38.fsf@linaro.org> From: Thomas Huth Message-ID: <15e19a9e-8cb4-e767-f5d3-6b268948844e@tuxfamily.org> Date: Wed, 20 Feb 2019 16:38:11 +0100 MIME-Version: 1.0 In-Reply-To: <87va2eyy38.fsf@linaro.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] m68k gdb has stopped single stepping correctly List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: =?UTF-8?Q?Alex_Benn=c3=a9e?= , Lucien Anti-Spam Cc: "Emilio G. Cota" , "qemu-devel@nongnu.org" , Laurent Vivier On 24/01/2019 14.38, Alex Bennée wrote: > > Lucien Anti-Spam via Qemu-devel writes: > >> > On Thursday, January 24, 2019, 3:08:07 AM GMT+9, Emilio G. Cota wrote: > > On Wed, Jan 23, 2019 at 15:58:27 +0000, Lucien Anti-Spam via Qemu-devel wrote:> > Hi folks, >>>> I noticed that with 3.x release that the GDB options (-S -s) for certain CPU results in very weird stepping.Usually stops afer a few steps, whilst the stub continues responding the PC doesnt update, however, I have only deeply looked at the m68k. >>>> In the case of the m68K the SR gets the trace bit set (T=10b), and the PC doesnt update.The m68k gdbstub, and main gdbstub seem mostly unchanged.But it seems the INSN handling has changed greatly for the m68k. >>>> Does anyone have any ideas what happened?>> Can you please bisect to find at which point things start misbehaving? >>> >>> Thanks, >>> Emilio >> Understood, I was hoping my original post might jog someone's memory about the issue. >> Apparently not, so after some digging I found that it was introduced with the refactor to TranslatorOps, specifically two lines got dropped that update the PC if single-stepping is being performed ( commit 11ab74b01e0a8ea4973eed89c6b90fa6e4fb9fb6 ) >> Since its not valid to revert, shall I go ahead and submit a patch for >> these two lines? > > Yes please! Hi Lucien, did you ever sent the patch? I can't find it on the mailing list, and I think this bug is still pending? Thomas