From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King - ARM Linux admin Subject: Re: [PATCH v5 08/23] arm64: compat: Add KUSER_HELPERS config option Date: Fri, 22 Feb 2019 14:09:16 +0000 Message-ID: <20190222140916.cgnq22trogt4dnzc@shell.armlinux.org.uk> References: <20190222122430.21180-1-vincenzo.frascino@arm.com> <20190222122430.21180-9-vincenzo.frascino@arm.com> <20190222140427.GI42419@lakrids.cambridge.arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20190222140427.GI42419@lakrids.cambridge.arm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Mark Rutland Cc: linux-arch@vger.kernel.org, Shuah Khan , Arnd Bergmann , Catalin Marinas , Daniel Lezcano , Will Deacon , Ralf Baechle , Mark Salyzyn , Paul Burton , Dmitry Safonov <0x7f454c46@gmail.com>, Rasmus Villemoes , Thomas Gleixner , Vincenzo Frascino , Peter Collingbourne , linux-arm-kernel@lists.infradead.org List-Id: linux-arch.vger.kernel.org On Fri, Feb 22, 2019 at 02:04:27PM +0000, Mark Rutland wrote: > I believe that Will wanted to default the kuser helpers off, as applications > using them need the instruction emulation which is also disabled by default. > > I'm also not sure which binaries we expect to work on arm64, so I'm not sure if > the ARMv4 reference is correct. Do you expect ARMv4 - even ARMv4 OABI binaries to fail on ARM64? (I've run my OABI ARMv4 distro under KVM on Macchiatobin when I've needed to rebuild a RPM without problems - using its own gcc. No observable issues.) -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from pandora.armlinux.org.uk ([78.32.30.218]:36942 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726090AbfBVOJZ (ORCPT ); Fri, 22 Feb 2019 09:09:25 -0500 Date: Fri, 22 Feb 2019 14:09:16 +0000 From: Russell King - ARM Linux admin Subject: Re: [PATCH v5 08/23] arm64: compat: Add KUSER_HELPERS config option Message-ID: <20190222140916.cgnq22trogt4dnzc@shell.armlinux.org.uk> References: <20190222122430.21180-1-vincenzo.frascino@arm.com> <20190222122430.21180-9-vincenzo.frascino@arm.com> <20190222140427.GI42419@lakrids.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190222140427.GI42419@lakrids.cambridge.arm.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Mark Rutland Cc: Vincenzo Frascino , linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Arnd Bergmann , Ralf Baechle , Paul Burton , Daniel Lezcano , Thomas Gleixner , Mark Salyzyn , Peter Collingbourne , Shuah Khan , Dmitry Safonov <0x7f454c46@gmail.com>, Rasmus Villemoes Message-ID: <20190222140916.nztcFwNJaJU8TkhRO-ERA6ezw5AiXkLWxjmsQrI2ZPc@z> On Fri, Feb 22, 2019 at 02:04:27PM +0000, Mark Rutland wrote: > I believe that Will wanted to default the kuser helpers off, as applications > using them need the instruction emulation which is also disabled by default. > > I'm also not sure which binaries we expect to work on arm64, so I'm not sure if > the ARMv4 reference is correct. Do you expect ARMv4 - even ARMv4 OABI binaries to fail on ARM64? (I've run my OABI ARMv4 distro under KVM on Macchiatobin when I've needed to rebuild a RPM without problems - using its own gcc. No observable issues.) -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up