Date: Wed, 18 Feb 2009 06:01:06 +1100 From: Peter Jeremy <peterjeremy@optushome.com.au> To: freebsd-amd64@freebsd.org Subject: 32-bit truncation of 64-bit values Message-ID: <20090217190106.GB1351@server.vk2pj.dyndns.org>
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--82I3+IH0IqGh5yIs Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Having just tracked down an issue caused by a pointer-to-int truncation, it occurs to me that it might be "instructive" to change the amd64 memory map so that the botton 4GB of address-space was unmapped by default (ie code, data, bss, stack and mmap all default to above 4GB). I notice that the process space layout has already changed since 7.x was branched (at least the same executable runs on 7.x and SEGVs on -current due to a truncated pointer) and making this change might reveal more broken code. Given how close we are to 8.0, this might need to wait until after 8 is branched. --=20 Peter Jeremy --82I3+IH0IqGh5yIs Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.10 (FreeBSD) iEYEARECAAYFAkmbCXIACgkQ/opHv/APuIe0jQCeMbNbzkt0l6QwMl9srEkWm1Um vhcAoJgA9OEiRGWHgdHGEV4dzRKqAQSq =qwXM -----END PGP SIGNATURE----- --82I3+IH0IqGh5yIs--
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