From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f72.google.com (mail-wm0-f72.google.com [74.125.82.72]) by kanga.kvack.org (Postfix) with ESMTP id B74156B0022 for ; Mon, 2 Apr 2018 14:16:06 -0400 (EDT) Received: by mail-wm0-f72.google.com with SMTP id r78so6142438wmd.0 for ; Mon, 02 Apr 2018 11:16:06 -0700 (PDT) Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk. [2001:4d48:ad52:3201:214:fdff:fe10:1be6]) by mx.google.com with ESMTPS id 2si597031wrg.485.2018.04.02.11.16.05 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 02 Apr 2018 11:16:05 -0700 (PDT) Date: Mon, 2 Apr 2018 19:15:37 +0100 From: Russell King - ARM Linux Subject: Re: [PATCH v3 5/6] Initialize the mapping of KASan shadow memory Message-ID: <20180402181536.GJ16141@n2100.armlinux.org.uk> References: <20180402120440.31900-1-liuwenliang@huawei.com> <20180402120440.31900-6-liuwenliang@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Nicolas Pitre Cc: Abbott Liu , kstewart@linuxfoundation.org, tixy@linaro.org, grygorii.strashko@linaro.org, julien.thierry@arm.com, Catalin Marinas , linux@rasmusvillemoes.dk, dhowells@redhat.com, linux-mm@kvack.org, mark.rutland@arm.com, kvmarm@lists.cs.columbia.edu, f.fainelli@gmail.com, Jonathan Corbet , linux-doc@vger.kernel.org, kasan-dev@googlegroups.com, geert@linux-m68k.org, linux-arm-kernel@lists.infradead.org, zhichao.huang@linaro.org, aryabinin@virtuozzo.com, labbott@redhat.com, vladimir.murzin@arm.com, keescook@chromium.org, Arnd Bergmann , marc.zyngier@arm.com, philip@cog.systems, jinb.park7@gmail.com, opendmb@gmail.com, tglx@linutronix.de, dvyukov@google.com, ard.biesheuvel@linaro.org, gregkh@linuxfoundation.org, mawilcox@microsoft.com, linux-kernel@vger.kernel.org, alexander.levin@verizon.com, james.morse@arm.com, kirill.shutemov@linux.intel.com, pombredanne@nexb.com, Andrew Morton , thgarnie@google.com, christoffer.dall@linaro.org On Mon, Apr 02, 2018 at 02:08:13PM -0400, Nicolas Pitre wrote: > On Mon, 2 Apr 2018, Abbott Liu wrote: > > > index c79b829..20161e2 100644 > > --- a/arch/arm/kernel/head-common.S > > +++ b/arch/arm/kernel/head-common.S > > @@ -115,6 +115,9 @@ __mmap_switched: > > str r8, [r2] @ Save atags pointer > > cmp r3, #0 > > strne r10, [r3] @ Save control register values > > +#ifdef CONFIG_KASAN > > + bl kasan_early_init > > +#endif > > mov lr, #0 > > b start_kernel > > ENDPROC(__mmap_switched) > > Would be better if lr was cleared before calling kasan_early_init. No. The code is correct - please remember that "bl" writes to LR. The point of clearing LR here is to ensure that start_kernel is called with a zero link register, which it won't be if kasan_early_init is moved after it. -- 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