From mboxrd@z Thu Jan 1 00:00:00 1970 Reply-To: kernel-hardening@lists.openwall.com Message-ID: <4F3DD30A.6030008@zytor.com> Date: Thu, 16 Feb 2012 20:09:46 -0800 From: "H. Peter Anvin" MIME-Version: 1.0 References: <1329422549-16407-1-git-send-email-wad@chromium.org> <1329422549-16407-3-git-send-email-wad@chromium.org> <4F3D61CB.2000301@zytor.com> <4F3D7250.6040504@zytor.com> <501858544d264abc6526f2b25a224f2b.squirrel@webmail.greenhost.nl> <4F3DAE5D.3080000@zytor.com> <4F3DB9E8.7040406@zytor.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: [kernel-hardening] Re: [PATCH v8 3/8] seccomp: add system call filtering using BPF To: Indan Zupancic Cc: Andrew Lutomirski , Will Drewry , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-doc@vger.kernel.org, kernel-hardening@lists.openwall.com, netdev@vger.kernel.org, x86@kernel.org, arnd@arndb.de, davem@davemloft.net, mingo@redhat.com, oleg@redhat.com, peterz@infradead.org, rdunlap@xenotime.net, mcgrathr@chromium.org, tglx@linutronix.de, eparis@redhat.com, serge.hallyn@canonical.com, djm@mindrot.org, scarybeasts@gmail.com, pmoore@redhat.com, akpm@linux-foundation.org, corbet@lwn.net, eric.dumazet@gmail.com, markus@chromium.org, keescook@chromium.org List-ID: On 02/16/2012 07:27 PM, Indan Zupancic wrote: > > A JIT won't be able to merge accesses because it also has to merge other > instructions and recognize when 64-bit operations are done with 32-bit > instructions. I think that will be too hard for a JIT. > Please Google "peephole optimizer". -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf. From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: [PATCH v8 3/8] seccomp: add system call filtering using BPF Date: Thu, 16 Feb 2012 20:09:46 -0800 Message-ID: <4F3DD30A.6030008@zytor.com> References: <1329422549-16407-1-git-send-email-wad@chromium.org> <1329422549-16407-3-git-send-email-wad@chromium.org> <4F3D61CB.2000301@zytor.com> <4F3D7250.6040504@zytor.com> <501858544d264abc6526f2b25a224f2b.squirrel@webmail.greenhost.nl> <4F3DAE5D.3080000@zytor.com> <4F3DB9E8.7040406@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from terminus.zytor.com ([198.137.202.10]:37015 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751364Ab2BQEKx (ORCPT ); Thu, 16 Feb 2012 23:10:53 -0500 In-Reply-To: Sender: linux-arch-owner@vger.kernel.org List-ID: To: Indan Zupancic Cc: Andrew Lutomirski , Will Drewry , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-doc@vger.kernel.org, kernel-hardening@lists.openwall.com, netdev@vger.kernel.org, x86@kernel.org, arnd@arndb.de, davem@davemloft.net, mingo@redhat.com, oleg@redhat.com, peterz@infradead.org, rdunlap@xenotime.net, mcgrathr@chromium.org, tglx@linutronix.de, eparis@redhat.com, serge.hallyn@canonical.com, djm@mindrot.org, scarybeasts@gmail.com, pmoore@redhat.com, akpm@linux-foundation.org, corbet@lwn.net, eric.dumazet@gmail.com, markus@chromium.org, keescook@chromium.org On 02/16/2012 07:27 PM, Indan Zupancic wrote: > > A JIT won't be able to merge accesses because it also has to merge other > instructions and recognize when 64-bit operations are done with 32-bit > instructions. I think that will be too hard for a JIT. > Please Google "peephole optimizer". -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.