Date: Sat, 14 Jun 2008 19:44:12 +0200 From: Ed Schouten <ed@80386.nl> To: amd64@freebsd.org Subject: VM_PROT_EXEC on the stack Message-ID: <20080614174412.GU1176@hoeg.nl>
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--2HdWiV8iqzNK3pYB Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hello everyone, I'm not a real guru when it comes to low level x86 hardware stuff, but some time ago I read somewhere that the NX bit on AMD64 CPU's could be used to mark the stack as non-executable, making it impossible to execute code on the stack (through buffer overflows). When I look at procstat -v's output on FreeBSD/amd64, I see the stack has VM_PROT_EXEC. Is there a specific reason for this? Yours, --=20 Ed Schouten <ed@80386.nl> WWW: http://80386.nl/ --2HdWiV8iqzNK3pYB Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (FreeBSD) iEYEARECAAYFAkhUA2sACgkQ52SDGA2eCwWKqwCeP4RoAf451eVuPiT1qjMNHrZL dtUAn0GgV5u/WgwqVqHMNX86f+ZFlLLG =nBON -----END PGP SIGNATURE----- --2HdWiV8iqzNK3pYB--
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