From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from atrey.karlin.mff.cuni.cz (atrey.karlin.mff.cuni.cz [195.113.26.193]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3wsJp34jwczDqhp for ; Tue, 20 Jun 2017 17:07:54 +1000 (AEST) Date: Tue, 20 Jun 2017 09:07:49 +0200 From: Pavel Machek To: Ram Pai Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, khandual@linux.vnet.ibm.com, aneesh.kumar@linux.vnet.ibm.com, bsingharora@gmail.com, dave.hansen@intel.com, hbabu@us.ibm.com Subject: Re: [RFC PATCH 0/7 v1] powerpc: Memory Protection Keys Message-ID: <20170620070749.GC30728@amd> References: <1496711109-4968-1-git-send-email-linuxram@us.ibm.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="oTHb8nViIGeoXxdp" In-Reply-To: <1496711109-4968-1-git-send-email-linuxram@us.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --oTHb8nViIGeoXxdp Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > Memory protection keys enable applications to protect its > address space from inadvertent access or corruption from > itself. >=20 > The overall idea: >=20 > A process allocates a key and associates it with > a address range within its address space. > The process than can dynamically set read/write=20 > permissions on the key without involving the=20 > kernel. Any code that violates the permissions > off the address space; as defined by its associated > key, will receive a segmentation fault. Do you have some documentation how userspace should use this? Will it be possible to hide details in libc so that it works across architectures? Do you have some kind of library that hides them? Where would you like it to be used? Web browsers? How does it interact with ptrace()? With /dev/mem? With /proc/XXX/mem? Will it enable malware to become very hard to understand? Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --oTHb8nViIGeoXxdp Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAllIycUACgkQMOfwapXb+vIfewCfRfyhEb2y0Gr9TeVhfXPG+sIk b5wAoKwnWJyjAdk99neXgO/s1nqNtq81 =u4PP -----END PGP SIGNATURE----- --oTHb8nViIGeoXxdp--