From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=34667 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Ox63Z-0002sk-Hl for qemu-devel@nongnu.org; Sat, 18 Sep 2010 18:38:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1Ox5oj-0000Nr-Ee for qemu-devel@nongnu.org; Sat, 18 Sep 2010 18:23:34 -0400 Received: from fmmailgate01.web.de ([217.72.192.221]:58098) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1Ox5oj-0000NW-1l for qemu-devel@nongnu.org; Sat, 18 Sep 2010 18:23:33 -0400 Message-ID: <4C953BDC.1030900@web.de> Date: Sun, 19 Sep 2010 00:23:24 +0200 From: Jan Kiszka MIME-Version: 1.0 References: <4C92BC9D.40707@web.de> In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigEB6B1FEB38F66D552A5E075F" Sender: jan.kiszka@web.de Subject: [Qemu-devel] Re: Commit 5f30fa18ad043a841fe9f0c3917ac60f2519ebd1 breaks debugging 64 bit guests List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Ted Harkington Cc: qemu-devel@nongnu.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigEB6B1FEB38F66D552A5E075F Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Am 18.09.2010 23:23, Ted Harkington wrote: > Without that commit, I can set breakpoints and debug 32 bit code AND 64= bit > code just fine in the same debug session... Then gdb will then debug 32-bit code in 64-bit mode as that's the architecture in use. That's not seriously usable if you look closer. >=20 > "set arch" does nothing to remedy my problems. >=20 > I cannot even set breakpoints before the system runs, let alone after I= > interrupt it... gdb does not support setting a 64-bit breakpoints when debugging a 16- or 32-bit target, and vice versa. As I said, you need to interrupt your guest while in 64-bit mode, set your breakpoint and reset the guest if it passed it already. >=20 > Are you sure this approach is needed? I have no such problems with boch= s... It is mandatory for source-level debugging. E.g. stack backtraces in 16 or 32-bit mode are broken otherwise. The problem is that gdb has no clue about the processor mode in use on the target. It derives it from the target architecture which is OK for application debugging (and that's what gdb is still designed for) but it's insufficient for system-level debugging. I don't know how bochs deals with this, but it faces the very same gdb limitation. Jan --------------enigEB6B1FEB38F66D552A5E075F Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.15 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org/ iEYEARECAAYFAkyVO+EACgkQitSsb3rl5xQxHQCg7dq9SNvTH6ybkH+e4L8gxQdI 2vwAoMrRdVOygvYyng5e3dQMlRbWR+Tj =8y88 -----END PGP SIGNATURE----- --------------enigEB6B1FEB38F66D552A5E075F--