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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 57867C2D0C9 for ; Thu, 12 Dec 2019 10:32:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2C9032067C for ; Thu, 12 Dec 2019 10:32:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728756AbfLLKcn (ORCPT ); Thu, 12 Dec 2019 05:32:43 -0500 Received: from foss.arm.com ([217.140.110.172]:41590 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728605AbfLLKcm (ORCPT ); Thu, 12 Dec 2019 05:32:42 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A5204328; Thu, 12 Dec 2019 02:32:41 -0800 (PST) Received: from [10.1.196.105] (eglon.cambridge.arm.com [10.1.196.105]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DA63E3F6CF; Thu, 12 Dec 2019 02:32:39 -0800 (PST) Subject: Re: [RESEND PATCH v5 5/5] Documentation/vmcoreinfo: Add documentation for 'TCR_EL1.T1SZ' To: Bhupesh Sharma , linux-kernel@vger.kernel.org Cc: bhupesh.linux@gmail.com, x86@kernel.org, linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, kexec@lists.infradead.org, Mark Rutland , Will Deacon , Steve Capper , Catalin Marinas , Ard Biesheuvel , Dave Anderson , Kazuhito Hagio References: <1575057559-25496-1-git-send-email-bhsharma@redhat.com> <1575057559-25496-6-git-send-email-bhsharma@redhat.com> From: James Morse Message-ID: <8a982138-f1fa-34e8-18fd-49a79cea3652@arm.com> Date: Thu, 12 Dec 2019 10:32:38 +0000 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <1575057559-25496-6-git-send-email-bhsharma@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Bhupesh, On 29/11/2019 19:59, Bhupesh Sharma wrote: > Add documentation for TCR_EL1.T1SZ variable being added to > vmcoreinfo. > > It indicates the size offset of the memory region addressed by TTBR1_EL1 > and hence can be used for determining the vabits_actual value. used for determining random-internal-kernel-variable, that might not exist tomorrow. Could you describe how this is useful/necessary if a debugger wants to walk the page tables from the core file? I think this is a better argument. Wouldn't the documentation be better as part of the patch that adds the export? (... unless these have to go via different trees? ..) > diff --git a/Documentation/admin-guide/kdump/vmcoreinfo.rst b/Documentation/admin-guide/kdump/vmcoreinfo.rst > index 447b64314f56..f9349f9d3345 100644 > --- a/Documentation/admin-guide/kdump/vmcoreinfo.rst > +++ b/Documentation/admin-guide/kdump/vmcoreinfo.rst > @@ -398,6 +398,12 @@ KERNELOFFSET > The kernel randomization offset. Used to compute the page offset. If > KASLR is disabled, this value is zero. > > +TCR_EL1.T1SZ > +------------ > + > +Indicates the size offset of the memory region addressed by TTBR1_EL1 > +and hence can be used for determining the vabits_actual value. 'vabits_actual' may not exist when the next person comes to read this documentation (its going to rot really quickly). I think the first half of this text is enough to say what this is for. You should include words to the effect that its the hardware value that goes with swapper_pg_dir. You may want to point readers to the arm-arm for more details on what the value means. Thanks, James 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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 9300BC43603 for ; Thu, 12 Dec 2019 10:40:53 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 45FD7206DA for ; Thu, 12 Dec 2019 10:40:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 45FD7206DA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 47YVh32zVBzDqq3 for ; Thu, 12 Dec 2019 21:40:51 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=arm.com (client-ip=217.140.110.172; helo=foss.arm.com; envelope-from=james.morse@arm.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=arm.com Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lists.ozlabs.org (Postfix) with ESMTP id 47YVdp1XPtzDqf5 for ; Thu, 12 Dec 2019 21:38:52 +1100 (AEDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A5204328; Thu, 12 Dec 2019 02:32:41 -0800 (PST) Received: from [10.1.196.105] (eglon.cambridge.arm.com [10.1.196.105]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DA63E3F6CF; Thu, 12 Dec 2019 02:32:39 -0800 (PST) Subject: Re: [RESEND PATCH v5 5/5] Documentation/vmcoreinfo: Add documentation for 'TCR_EL1.T1SZ' To: Bhupesh Sharma , linux-kernel@vger.kernel.org References: <1575057559-25496-1-git-send-email-bhsharma@redhat.com> <1575057559-25496-6-git-send-email-bhsharma@redhat.com> From: James Morse Message-ID: <8a982138-f1fa-34e8-18fd-49a79cea3652@arm.com> Date: Thu, 12 Dec 2019 10:32:38 +0000 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <1575057559-25496-6-git-send-email-bhsharma@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Ard Biesheuvel , linux-doc@vger.kernel.org, Will Deacon , x86@kernel.org, kexec@lists.infradead.org, Kazuhito Hagio , Dave Anderson , Catalin Marinas , bhupesh.linux@gmail.com, linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org, Steve Capper Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Hi Bhupesh, On 29/11/2019 19:59, Bhupesh Sharma wrote: > Add documentation for TCR_EL1.T1SZ variable being added to > vmcoreinfo. > > It indicates the size offset of the memory region addressed by TTBR1_EL1 > and hence can be used for determining the vabits_actual value. used for determining random-internal-kernel-variable, that might not exist tomorrow. Could you describe how this is useful/necessary if a debugger wants to walk the page tables from the core file? I think this is a better argument. Wouldn't the documentation be better as part of the patch that adds the export? (... unless these have to go via different trees? ..) > diff --git a/Documentation/admin-guide/kdump/vmcoreinfo.rst b/Documentation/admin-guide/kdump/vmcoreinfo.rst > index 447b64314f56..f9349f9d3345 100644 > --- a/Documentation/admin-guide/kdump/vmcoreinfo.rst > +++ b/Documentation/admin-guide/kdump/vmcoreinfo.rst > @@ -398,6 +398,12 @@ KERNELOFFSET > The kernel randomization offset. Used to compute the page offset. If > KASLR is disabled, this value is zero. > > +TCR_EL1.T1SZ > +------------ > + > +Indicates the size offset of the memory region addressed by TTBR1_EL1 > +and hence can be used for determining the vabits_actual value. 'vabits_actual' may not exist when the next person comes to read this documentation (its going to rot really quickly). I think the first half of this text is enough to say what this is for. You should include words to the effect that its the hardware value that goes with swapper_pg_dir. You may want to point readers to the arm-arm for more details on what the value means. Thanks, James 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=-5.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,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 894DBC43603 for ; Thu, 12 Dec 2019 10:33:02 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 576A2214D8 for ; Thu, 12 Dec 2019 10:33:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="umZ61QIK" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 576A2214D8 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date: Message-ID:From:References:To:Subject:Reply-To:Content-ID:Content-Description :Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=fAbx+Hc1W6knTV3rZqOuuGsdvdbioijbENnpZ1O/r38=; b=umZ61QIKZWryOi dBlm0P+6SHs4IloYEoOF6abHEVqDK+EwtErJJkNBRX/VwZ8IhO2EXXjMkmvPVADGxspJP6YYRZ+D9 6O1eMeYDXMVQ4LdbsZTd+tsdyFfNRnT3wzLnTx69nhDnaKk2mO0+xFo1GaC1kLnNJ5mGI6QYJAlbR knDApw8ytUW9QVJJEukgkYZkU2pNz7+THQqqZAFOqeF+wdds7Rbwf/TxaVznfoqsAZiCCsMZlT7Hi seN6lRwHQ0fi+tRUvLfccvkSeXezofjFITHcwDQGIHJVRzxXzs2ZbiuB1rIvW9OpWD7BCfAmeZgW6 Mv9jQwbDzuXu2awGwWDQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1ifLm9-0007KV-Du; Thu, 12 Dec 2019 10:32:53 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1ifLm3-0007HY-4Y; Thu, 12 Dec 2019 10:32:51 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A5204328; Thu, 12 Dec 2019 02:32:41 -0800 (PST) Received: from [10.1.196.105] (eglon.cambridge.arm.com [10.1.196.105]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DA63E3F6CF; Thu, 12 Dec 2019 02:32:39 -0800 (PST) Subject: Re: [RESEND PATCH v5 5/5] Documentation/vmcoreinfo: Add documentation for 'TCR_EL1.T1SZ' To: Bhupesh Sharma , linux-kernel@vger.kernel.org References: <1575057559-25496-1-git-send-email-bhsharma@redhat.com> <1575057559-25496-6-git-send-email-bhsharma@redhat.com> From: James Morse Message-ID: <8a982138-f1fa-34e8-18fd-49a79cea3652@arm.com> Date: Thu, 12 Dec 2019 10:32:38 +0000 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <1575057559-25496-6-git-send-email-bhsharma@redhat.com> Content-Language: en-GB X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191212_023249_960547_9E3A3475 X-CRM114-Status: GOOD ( 14.85 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Ard Biesheuvel , linux-doc@vger.kernel.org, Will Deacon , x86@kernel.org, kexec@lists.infradead.org, Kazuhito Hagio , Dave Anderson , Catalin Marinas , bhupesh.linux@gmail.com, linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org, Steve Capper Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Bhupesh, On 29/11/2019 19:59, Bhupesh Sharma wrote: > Add documentation for TCR_EL1.T1SZ variable being added to > vmcoreinfo. > > It indicates the size offset of the memory region addressed by TTBR1_EL1 > and hence can be used for determining the vabits_actual value. used for determining random-internal-kernel-variable, that might not exist tomorrow. Could you describe how this is useful/necessary if a debugger wants to walk the page tables from the core file? I think this is a better argument. Wouldn't the documentation be better as part of the patch that adds the export? (... unless these have to go via different trees? ..) > diff --git a/Documentation/admin-guide/kdump/vmcoreinfo.rst b/Documentation/admin-guide/kdump/vmcoreinfo.rst > index 447b64314f56..f9349f9d3345 100644 > --- a/Documentation/admin-guide/kdump/vmcoreinfo.rst > +++ b/Documentation/admin-guide/kdump/vmcoreinfo.rst > @@ -398,6 +398,12 @@ KERNELOFFSET > The kernel randomization offset. Used to compute the page offset. If > KASLR is disabled, this value is zero. > > +TCR_EL1.T1SZ > +------------ > + > +Indicates the size offset of the memory region addressed by TTBR1_EL1 > +and hence can be used for determining the vabits_actual value. 'vabits_actual' may not exist when the next person comes to read this documentation (its going to rot really quickly). I think the first half of this text is enough to say what this is for. You should include words to the effect that its the hardware value that goes with swapper_pg_dir. You may want to point readers to the arm-arm for more details on what the value means. Thanks, James _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Subject: Re: [RESEND PATCH v5 5/5] Documentation/vmcoreinfo: Add documentation for 'TCR_EL1.T1SZ' References: <1575057559-25496-1-git-send-email-bhsharma@redhat.com> <1575057559-25496-6-git-send-email-bhsharma@redhat.com> From: James Morse Message-ID: <8a982138-f1fa-34e8-18fd-49a79cea3652@arm.com> Date: Thu, 12 Dec 2019 10:32:38 +0000 MIME-Version: 1.0 In-Reply-To: <1575057559-25496-6-git-send-email-bhsharma@redhat.com> Content-Language: en-GB List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Bhupesh Sharma , linux-kernel@vger.kernel.org Cc: Mark Rutland , Ard Biesheuvel , linux-doc@vger.kernel.org, Will Deacon , x86@kernel.org, kexec@lists.infradead.org, Kazuhito Hagio , Dave Anderson , Catalin Marinas , bhupesh.linux@gmail.com, linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org, Steve Capper Hi Bhupesh, On 29/11/2019 19:59, Bhupesh Sharma wrote: > Add documentation for TCR_EL1.T1SZ variable being added to > vmcoreinfo. > > It indicates the size offset of the memory region addressed by TTBR1_EL1 > and hence can be used for determining the vabits_actual value. used for determining random-internal-kernel-variable, that might not exist tomorrow. Could you describe how this is useful/necessary if a debugger wants to walk the page tables from the core file? I think this is a better argument. Wouldn't the documentation be better as part of the patch that adds the export? (... unless these have to go via different trees? ..) > diff --git a/Documentation/admin-guide/kdump/vmcoreinfo.rst b/Documentation/admin-guide/kdump/vmcoreinfo.rst > index 447b64314f56..f9349f9d3345 100644 > --- a/Documentation/admin-guide/kdump/vmcoreinfo.rst > +++ b/Documentation/admin-guide/kdump/vmcoreinfo.rst > @@ -398,6 +398,12 @@ KERNELOFFSET > The kernel randomization offset. Used to compute the page offset. If > KASLR is disabled, this value is zero. > > +TCR_EL1.T1SZ > +------------ > + > +Indicates the size offset of the memory region addressed by TTBR1_EL1 > +and hence can be used for determining the vabits_actual value. 'vabits_actual' may not exist when the next person comes to read this documentation (its going to rot really quickly). I think the first half of this text is enough to say what this is for. You should include words to the effect that its the hardware value that goes with swapper_pg_dir. You may want to point readers to the arm-arm for more details on what the value means. Thanks, James _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec