From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752772AbdJSMmr (ORCPT ); Thu, 19 Oct 2017 08:42:47 -0400 Received: from pandora.armlinux.org.uk ([78.32.30.218]:60532 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752713AbdJSMmq (ORCPT ); Thu, 19 Oct 2017 08:42:46 -0400 Date: Thu, 19 Oct 2017 13:41:49 +0100 From: Russell King - ARM Linux To: Ard Biesheuvel Cc: "Liuwenliang (Lamb)" , "tixy@linaro.org" , "mhocko@suse.com" , "grygorii.strashko@linaro.org" , "catalin.marinas@arm.com" , "linux-mm@kvack.org" , "glider@google.com" , "afzal.mohd.ma@gmail.com" , "mingo@kernel.org" , "cdall@linaro.org" , "f.fainelli@gmail.com" , kbuild test robot , "mawilcox@microsoft.com" , "kasan-dev@googlegroups.com" , Dailei , "linux-arm-kernel@lists.infradead.org" , "aryabinin@virtuozzo.com" , "labbott@redhat.com" , "vladimir.murzin@arm.com" , "keescook@chromium.org" , "arnd@arndb.de" , "marc.zyngier@arm.com" , Zengweilin , "opendmb@gmail.com" , Heshaoliang , "tglx@linutronix.de" , "dvyukov@google.com" , "linux-kernel@vger.kernel.org" , "kbuild-all@01.org" , Jiazhenghua , "akpm@linux-foundation.org" , "robin.murphy@arm.com" , "thgarnie@google.com" , "kirill.shutemov@linux.intel.com" Subject: Re: [PATCH 04/11] Define the virtual space of KASan's shadow region Message-ID: <20171019124149.GX20805@n2100.armlinux.org.uk> References: <20171011082227.20546-5-liuwenliang@huawei.com> <201710141957.mbxeZJHB%fengguang.wu@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 16, 2017 at 01:14:54PM +0100, Ard Biesheuvel wrote: > On 16 October 2017 at 12:42, Liuwenliang (Lamb) wrote: > > On 10/16/2017 07:03 PM, Abbott Liu wrote: > >>arch/arm/kernel/entry-armv.S:348: Error: selected processor does not support `movw r1, > > #:lower16:((((0xC0000000-0x01000000)>>3)+((0xC0000000-0x01000000)-(1<<29))))' in ARM mode > >>arch/arm/kernel/entry-armv.S:348: Error: selected processor does not support `movt r1, > > #:upper16:((((0xC0000000-0x01000000)>>3)+((0xC0000000-0x01000000)-(1<<29))))' in ARM mode > > > > Thanks for building test. This error can be solved by following code: > > --- a/arch/arm/kernel/entry-armv.S > > +++ b/arch/arm/kernel/entry-armv.S > > @@ -188,8 +188,7 @@ ENDPROC(__und_invalid) > > get_thread_info tsk > > ldr r0, [tsk, #TI_ADDR_LIMIT] > > #ifdef CONFIG_KASAN > > - movw r1, #:lower16:TASK_SIZE > > - movt r1, #:upper16:TASK_SIZE > > + ldr r1, =TASK_SIZE > > #else > > mov r1, #TASK_SIZE > > #endif > > This is unnecessary: > > ldr r1, =TASK_SIZE > > will be converted to a mov instruction by the assembler if the value > of TASK_SIZE fits its 12-bit immediate field. It's an 8-bit immediate field for ARM. What it won't do is expand it to a pair of movw/movt instructions if it doesn't fit. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 8.8Mbps down 630kbps up According to speedtest.net: 8.21Mbps down 510kbps up