From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 79D1EC32751 for ; Wed, 7 Aug 2019 13:03:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5BB9F21E6C for ; Wed, 7 Aug 2019 13:03:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388065AbfHGNDc (ORCPT ); Wed, 7 Aug 2019 09:03:32 -0400 Received: from ozlabs.org ([203.11.71.1]:46493 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727213AbfHGND3 (ORCPT ); Wed, 7 Aug 2019 09:03:29 -0400 Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 463WsC1bBxz9sBF; Wed, 7 Aug 2019 23:03:27 +1000 (AEST) From: Michael Ellerman To: Jason Yan , linuxppc-dev@lists.ozlabs.org, diana.craciun@nxp.com, christophe.leroy@c-s.fr, benh@kernel.crashing.org, paulus@samba.org, npiggin@gmail.com, keescook@chromium.org, kernel-hardening@lists.openwall.com Cc: linux-kernel@vger.kernel.org, wangkefeng.wang@huawei.com, yebin10@huawei.com, thunder.leizhen@huawei.com, jingxiangfeng@huawei.com, fanchengyang@huawei.com, zhaohongjiang@huawei.com, Jason Yan Subject: Re: [PATCH v5 03/10] powerpc: introduce kimage_vaddr to store the kernel base In-Reply-To: <20190807065706.11411-4-yanaijie@huawei.com> References: <20190807065706.11411-1-yanaijie@huawei.com> <20190807065706.11411-4-yanaijie@huawei.com> Date: Wed, 07 Aug 2019 23:03:23 +1000 Message-ID: <8736idunz8.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jason Yan writes: > Now the kernel base is a fixed value - KERNELBASE. To support KASLR, we > need a variable to store the kernel base. > > Signed-off-by: Jason Yan > Cc: Diana Craciun > Cc: Michael Ellerman > Cc: Christophe Leroy > Cc: Benjamin Herrenschmidt > Cc: Paul Mackerras > Cc: Nicholas Piggin > Cc: Kees Cook > Reviewed-by: Christophe Leroy > Reviewed-by: Diana Craciun > Tested-by: Diana Craciun > --- > arch/powerpc/include/asm/page.h | 2 ++ > arch/powerpc/mm/init-common.c | 2 ++ > 2 files changed, 4 insertions(+) > > diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h > index 0d52f57fca04..60a68d3a54b1 100644 > --- a/arch/powerpc/include/asm/page.h > +++ b/arch/powerpc/include/asm/page.h > @@ -315,6 +315,8 @@ void arch_free_page(struct page *page, int order); > > struct vm_area_struct; > > +extern unsigned long kimage_vaddr; > + > #include > #endif /* __ASSEMBLY__ */ > #include > diff --git a/arch/powerpc/mm/init-common.c b/arch/powerpc/mm/init-common.c > index 152ae0d21435..d4801ce48dc5 100644 > --- a/arch/powerpc/mm/init-common.c > +++ b/arch/powerpc/mm/init-common.c > @@ -25,6 +25,8 @@ phys_addr_t memstart_addr = (phys_addr_t)~0ull; > EXPORT_SYMBOL_GPL(memstart_addr); > phys_addr_t kernstart_addr; > EXPORT_SYMBOL_GPL(kernstart_addr); > +unsigned long kimage_vaddr = KERNELBASE; > +EXPORT_SYMBOL_GPL(kimage_vaddr); The names of the #defines and variables we use for these values are not very consistent already, but using kimage_vaddr makes it worse I think. Isn't this going to have the same value as kernstart_addr, but the virtual rather than physical address? If so kernstart_virt_addr would seem better. cheers