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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 03AFCC001DF for ; Mon, 31 Jul 2023 21:58:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231758AbjGaV6U (ORCPT ); Mon, 31 Jul 2023 17:58:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36122 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231731AbjGaV6O (ORCPT ); Mon, 31 Jul 2023 17:58:14 -0400 Received: from mail-wm1-x333.google.com (mail-wm1-x333.google.com [IPv6:2a00:1450:4864:20::333]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 11F6FE8; Mon, 31 Jul 2023 14:58:13 -0700 (PDT) Received: by mail-wm1-x333.google.com with SMTP id 5b1f17b1804b1-3fe110de46dso29448045e9.1; Mon, 31 Jul 2023 14:58:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1690840691; x=1691445491; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=JW14MFDPt7O1rcxZlX3cjPvtcLYMaz4AwpOhoYK6iUw=; b=NoikV3xA1O/NOK72COlWGTe4BOUUrbAnvaSMxJnyaErguIfABUUDmVFL0Ow82LSF/t 61OTPKrb8YnO0RQKXRQ0611KfYzRdXVGvLjA4Xjs7hurhUpAOx3hk3CZ6xwRv7hPqiRL 6oPir5NA51VhlU2/utl9iABuVnWBZsTcGCsYo25fPwJxFlxr+fUF5nUnQXLQq3VYGq+Q W+hb2YpYga6Bmvpe4b/11q5EfKejbxyey5u4GfJBPJwrwOhhivqGygsK8rCUjB5E/z7J IHa5gPpVlZ6DCv2O4EW8BCoYhi8MMP/e1tC8J+4MmAOccCtzmp+uCsiHbd3NCjYyBuqs YrbA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690840691; x=1691445491; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=JW14MFDPt7O1rcxZlX3cjPvtcLYMaz4AwpOhoYK6iUw=; b=MTAsS06W7Thc6DZ41nE0n4HPHpON7HWovqYdwSYrZKk76grH22pV8sZvu0wAZkcB1z v8hioUAJWBF4JVH44xh0qgF5HdAUagOJeZOwA/oyaZQAZO+x77xCZHHgEkPtM2yp5t6Y 2VAHDCeLTHvWp3JVtO9LzS037RX0xl6ex469GWrjzc+ScPSVBKf/m9WXO4Vi52sgotJj U0qvL0XITXHSFOZAeC6yQgjP0RV3LYxp3q9zUi/IFOz9tBUgF8XaQser7RJdudkVtdSk q+Hxmy1sIgkS5wJmlgiVAO3/UEquFawp0DDkCPMNvVm/1JARaGRj/gtHij6AHDTQ0ooB x2Eg== X-Gm-Message-State: ABy/qLbZY4e1CrYgFttlRfU6wSt16LCR4qx56/RFhZy7ThTU7OY8dC5k sC5d6LG/mGnHc/e/cP17Fls= X-Google-Smtp-Source: APBJJlFi0UY75YZJevKOpFRyWSmg2oW4GKvdcQMMibjE0tT9Qjx44yT4rtUcFE8PJ2qzc1bU//TrpA== X-Received: by 2002:a7b:cc11:0:b0:3fe:1d34:908 with SMTP id f17-20020a7bcc11000000b003fe1d340908mr840278wmh.17.1690840691157; Mon, 31 Jul 2023 14:58:11 -0700 (PDT) Received: from localhost ([2a00:23c5:dc8c:8701:1663:9a35:5a7b:1d76]) by smtp.gmail.com with ESMTPSA id 8-20020a05600c028800b003fb225d414fsm14945629wmk.21.2023.07.31.14.58.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 31 Jul 2023 14:58:10 -0700 (PDT) Date: Mon, 31 Jul 2023 22:58:09 +0100 From: Lorenzo Stoakes To: Jiri Olsa Cc: David Hildenbrand , Baoquan He , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Andrew Morton , Uladzislau Rezki , Matthew Wilcox , Liu Shixin , Jens Axboe , Alexander Viro Subject: Re: [PATCH v8 1/4] fs/proc/kcore: avoid bounce buffer for ktext data Message-ID: <27ad89fe-1b69-4d62-916f-d494b32c8ddf@lucifer.local> References: <86fd0ccb-f460-651f-8048-1026d905a2d6@redhat.com> <32b8c5e4-c8e3-0244-1b1a-ca33bd44f38a@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 31, 2023 at 11:50:22PM +0200, Jiri Olsa wrote: > > Ummmm what? I can't! What repro are you seeing on x86, exactly? > > # cat /proc/kallsyms | grep ksys_read > ffffffff8151e450 T ksys_read > > # objdump -d --start-address=0xffffffff8151e450 --stop-address=0xffffffff8151e460 /proc/kcore > > /proc/kcore: file format elf64-x86-64 > > objdump: Reading section load1 failed because: Bad address > > > jirka Locally I don't see this issue. How odd. The bug doesn't manifest as a 'bad address' in the arm64 repros either. I wonder if this is something unrelated... In any case I have a candidate fix for the bug at https://lore.kernel.org/all/20230731215021.70911-1-lstoakes@gmail.com/ which should hopefully address the underlying issue with minimum change.