From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1KLfXm-0007vT-14 for qemu-devel@nongnu.org; Wed, 23 Jul 2008 10:42:18 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1KLfXk-0007uU-0O for qemu-devel@nongnu.org; Wed, 23 Jul 2008 10:42:17 -0400 Received: from [199.232.76.173] (port=45356 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1KLfXj-0007uR-RV for qemu-devel@nongnu.org; Wed, 23 Jul 2008 10:42:15 -0400 Received: from fmmailgate03.web.de ([217.72.192.234]:38102) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1KLfXi-0003V8-Pm for qemu-devel@nongnu.org; Wed, 23 Jul 2008 10:42:15 -0400 Message-ID: <4887433D.3080509@web.de> Date: Wed, 23 Jul 2008 16:42:05 +0200 From: Jan Kiszka MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH] linux-user: Fix page_find_alloc for 32-bit use on 64-bit hosts References: <487A658A.3060203@web.de> <200807231326.00691.paul@codesourcery.com> In-Reply-To: <200807231326.00691.paul@codesourcery.com> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig17F8062422EC5365DDF8A7B0" Sender: jan.kiszka@web.de 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 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig17F8062422EC5365DDF8A7B0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: quoted-printable Paul Brook wrote: > On Sunday 13 July 2008, Jan Kiszka wrote: >> page_find_alloc, used e.g. for TB allocation, is not safe on 64-bit >> hosts for 32-bit guests. Patch below fixes this by requesting new page= s >> only from the guest-reachable address range. >=20 > I'm pretty sure this is wrong. The structures allocated by page_find_al= loc do=20 > not need to be accessible by the guest. In fact it's better if they are= =20 > outside the guest address space. Bet we have "addr =3D h2g(p);" in page_find_alloc(), ie. we expect to retrieve a valid guest address (for use with page_set_flag). Something is borken here, but you can surely better tell us what precisely than I'm able to. Jan --------------enig17F8062422EC5365DDF8A7B0 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iEYEARECAAYFAkiHQ0QACgkQniDOoMHTA+miuACePnmTS9BW3CTX4JybK6OT4YGj XqoAn2PNeGf3Vs9LDX7zjP1+GE2IhuBt =EkEf -----END PGP SIGNATURE----- --------------enig17F8062422EC5365DDF8A7B0--