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 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id CA2AEC6FA8E for ; Thu, 2 Mar 2023 14:50:20 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.504978.777460 (Exim 4.92) (envelope-from ) id 1pXkFw-0006sb-PB; Thu, 02 Mar 2023 14:50:04 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 504978.777460; Thu, 02 Mar 2023 14:50:04 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pXkFw-0006sA-Kh; Thu, 02 Mar 2023 14:50:04 +0000 Received: by outflank-mailman (input) for mailman id 504978; Thu, 02 Mar 2023 14:50:02 +0000 Received: from mail.xenproject.org ([104.130.215.37]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pXkFu-0006ZR-TF for xen-devel@lists.xenproject.org; Thu, 02 Mar 2023 14:50:02 +0000 Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pXkFu-0003YH-H0; Thu, 02 Mar 2023 14:50:02 +0000 Received: from [15.248.2.148] (helo=[10.24.67.20]) by xenbits.xenproject.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1pXkFu-0003Hk-BY; Thu, 02 Mar 2023 14:50:02 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=xen.org; s=20200302mail; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:From: References:Cc:To:Subject:MIME-Version:Date:Message-ID; bh=5fe8Zad2At3QNtgzV6CN27Y1npXSjdEYhVSLoYTF1TA=; b=SERxtXvpHGISyJozv4vW5EXu6k M/sAzfO3cV6JylVih8lxeZjuxSTmUqVDuvjJ6uAGeoIqRmMlZgtOoIYGO1wyttKjCAbpCgbHeIiyU MIvd6hlaqsMQGpOLhAtyeyPeuwIVg9wLacI6yztPaoI9v5O5kKJ4nIGDXgXWws2hArdY=; Message-ID: Date: Thu, 2 Mar 2023 14:50:00 +0000 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.8.0 Subject: Re: [PATCH v1] xen/arm: align *(.proc.info) in the linker script Content-Language: en-US To: Oleksii , xen-devel@lists.xenproject.org Cc: Stefano Stabellini , Bertrand Marquis , Volodymyr Babchuk References: <74973920d8722df3ce533979314564f331acf16e.1677687247.git.oleksii.kurochko@gmail.com> <370809af-75e6-546a-53e4-71a76444f367@xen.org> <472fee066070db9cb3c662bf5cc6f8cb681aeb1b.camel@gmail.com> From: Julien Grall In-Reply-To: <472fee066070db9cb3c662bf5cc6f8cb681aeb1b.camel@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi Oleksii, On 02/03/2023 07:34, Oleksii wrote: > Hi Julien, >>>> On Wed, 2023-03-01 at 16:21 +0000, Julien Grall wrote: >>>>> Hi Oleksii, >>>>> >>>>> On 01/03/2023 16:14, Oleksii Kurochko wrote: >>>>>> During testing of bug.h's macros generic implementation >>>>>> yocto- >>>>>> qemuarm >>>>>> job crashed with data abort: >>>>> >>>>> The commit message is lacking some information. You are telling >>>>> us >>>>> that >>>>> there is an error when building with your series, but this >>>>> doesn't >>>>> tell >>>>> me why this is the correct fix. >>>>> >>>>> This is also why I asked to have the xen binary because I want >>>>> to >>>>> check >>>>> whether this was a latent bug in Xen or your series effectively >>>>> introduce a bug. >>>>> >>>>> Note that regardless what I just wrote this is a good idea to >>>>> align >>>>> __proc_info_start. I will try to have a closer look later and >>>>> propose >>>>> a >>>>> commit message and/or any action for your other series. >>>> Regarding binaries please take a look here: >>>> https://lore.kernel.org/xen-devel/aa2862eacccfb0574859bf4cda8f4992baa5d2e1.camel@gmail.com/ >>>> >>>> I am not sure if you get my answer as I had the message from >>>> delivery >>>> server that it was blocked for some reason. >>> >>> I got the answer. The problem now is gitlab only keep the artifact >>> for >>> the latest build and it only provide a zImage (having the ELF would >>> be >>> easier). >>> >>> I will try to reproduce the error on my end. >> >> I managed to reproduce it. It looks like that after your bug patch, >> *(.rodata.*) will not be end on a 4-byte boundary. Before your patch, >> all the messages will be in .rodata.str. Now they are in >> .bug_frames.*, >> so there some difference in .rodata.*. >> >> That said, it is not entirely clear why we never seen the issue >> before >> because my guessing there are no guarantee that .rodata.* will be >> suitably aligned. >> >> Anyway, here a proposal for the commit message: >> >> " >> xen/arm: Ensure the start *(.proc.info) of is 4-byte aligned >> >> The entries in *(.proc.info) are expected to be 4-byte aligned and >> the >> compiler will access them using 4-byte load instructions. On Arm32, >> the >> alignment is strictly enforced by the processor and will result to a >> data abort if it is not correct. >> >> However, the linker script doesn't encode this requirement. So we are >> at >> the mercy of the compiler/linker to have aligned the previous >> sections >> suitably. >> >> This was spotted when trying to use the upcoming generic bug >> infrastructure with the compiler provided by Yocto. >> >> Link: >> https://lore.kernel.org/xen-devel/6735859208c6dcb7320f89664ae298005f70827b.camel@gmail.com/ >> " >> >> If you are happy with the proposed commit message, then I can update >> it >> while committing. > I am happy with the proposed commit message. Thanks. With that: Reviewed-by: Julien Grall I have addressed Jan's comment and committed the patch. Cheers, -- Julien Grall