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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 ADEC2C433E6 for ; Mon, 1 Feb 2021 14:00:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7DF4D64E94 for ; Mon, 1 Feb 2021 14:00:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232157AbhBAN7l (ORCPT ); Mon, 1 Feb 2021 08:59:41 -0500 Received: from elvis.franken.de ([193.175.24.41]:43717 "EHLO elvis.franken.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232031AbhBAN7i (ORCPT ); Mon, 1 Feb 2021 08:59:38 -0500 Received: from uucp (helo=alpha) by elvis.franken.de with local-bsmtp (Exim 3.36 #1) id 1l6ZjC-0001Qe-00; Mon, 01 Feb 2021 14:58:54 +0100 Received: by alpha.franken.de (Postfix, from userid 1000) id 57C92C0D38; Mon, 1 Feb 2021 13:50:28 +0100 (CET) Date: Mon, 1 Feb 2021 13:50:28 +0100 From: Thomas Bogendoerfer To: Jinyang He Cc: Huacai Chen , Jiaxun Yang , linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] MIPS: relocatable: Provide kaslr_offset() to get the kernel offset Message-ID: <20210201125028.GA8621@alpha.franken.de> References: <1611720745-8256-1-git-send-email-hejinyang@loongson.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1611720745-8256-1-git-send-email-hejinyang@loongson.cn> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org On Wed, Jan 27, 2021 at 12:12:25PM +0800, Jinyang He wrote: > Use kimage_vaddr to indicate kernel start address. Provide kaslr_offset() > to get the kernel offset when KASLR is enabled. Error may occur before > update_kimage_vaddr(), so put it at the end of the offset branch. > > Fixes: a307a4ce9ecd ("MIPS: Loongson64: Add KASLR support") > Reported-by: kernel test robot > Signed-off-by: Jinyang He > --- > arch/mips/include/asm/page.h | 6 ++++++ > arch/mips/kernel/relocate.c | 12 ++++++++++++ > arch/mips/kernel/setup.c | 3 +++ > 3 files changed, 21 insertions(+) > > diff --git a/arch/mips/include/asm/page.h b/arch/mips/include/asm/page.h > index 6a77bc4..9429520 100644 > --- a/arch/mips/include/asm/page.h > +++ b/arch/mips/include/asm/page.h > @@ -255,6 +255,12 @@ extern bool __virt_addr_valid(const volatile void *kaddr); > > #define VM_DATA_DEFAULT_FLAGS VM_DATA_FLAGS_TSK_EXEC > > +extern unsigned long kimage_vaddr; > +static inline unsigned long kaslr_offset(void) > +{ > + return kimage_vaddr - VMLINUX_LOAD_ADDRESS; > +} this breaks for 32bit kernels: :0:22: error: large integer implicitly truncated to unsigned type [-Werror=overflow] /local/tbogendoerfer/korg/linux/arch/mips/kernel/setup.c:87:41: note: in expansion of macro ‘VMLINUX_LOAD_ADDRESS’ unsigned long kimage_vaddr __initdata = VMLINUX_LOAD_ADDRESS; ^~~~~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors -- Crap can work. Given enough thrust pigs will fly, but it's not necessarily a good idea. [ RFC1925, 2.3 ]