From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53140) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ab8ap-0005Lf-Vp for qemu-devel@nongnu.org; Wed, 02 Mar 2016 10:21:45 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ab8al-0002Nq-4M for qemu-devel@nongnu.org; Wed, 02 Mar 2016 10:21:39 -0500 Received: from smtp2-g21.free.fr ([2a01:e0c:1:1599::11]:13451) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ab8ak-0002NX-Uj for qemu-devel@nongnu.org; Wed, 02 Mar 2016 10:21:35 -0500 References: <1456931078-21635-1-git-send-email-pbonzini@redhat.com> From: =?UTF-8?Q?Herv=c3=a9_Poussineau?= Message-ID: <56D704F7.3010409@reactos.org> Date: Wed, 2 Mar 2016 16:21:27 +0100 MIME-Version: 1.0 In-Reply-To: <1456931078-21635-1-git-send-email-pbonzini@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH] target-i386: fix addr16 prefix List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini , qemu-devel@nongnu.org Cc: rth@twiddle.net Le 02/03/2016 16:04, Paolo Bonzini a =C3=A9crit : > While ADDSEG will only be false in 16-bit mode for LEA, it can be > false even in other cases when 16-bit addresses are obtained via > the 67h prefix in 32-bit mode. In this case, gen_lea_v_seg forgets > to add a nonzero FS or GS base if CS/DS/ES/SS are all zero. This > case is pretty rare but happens when booting Windows 95/98, and > this patch fixes it. > > The bug is visible since commit d6a291498, but it was introduced > together with gen_lea_v_seg and it probably could be reproduced > with a "addr16 gs movsb" instruction as early as in commit > ca2f29f555805d07fb0b9ebfbbfc4e3656530977. > > Cc: rth@twiddle.net > Reported-by: Herv=C3=A9 Poussineau > Signed-off-by: Paolo Bonzini Tested-by: Herv=C3=A9 Poussineau