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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 38A05C43381 for ; Fri, 22 Mar 2019 08:34:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0E4B82083D for ; Fri, 22 Mar 2019 08:34:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727831AbfCVIeZ (ORCPT ); Fri, 22 Mar 2019 04:34:25 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46720 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725981AbfCVIeZ (ORCPT ); Fri, 22 Mar 2019 04:34:25 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id F2F94307CDE3; Fri, 22 Mar 2019 08:34:24 +0000 (UTC) Received: from localhost (ovpn-12-81.pek2.redhat.com [10.72.12.81]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 56FF65D9CC; Fri, 22 Mar 2019 08:34:22 +0000 (UTC) Date: Fri, 22 Mar 2019 16:34:19 +0800 From: Baoquan He To: Pingfan Liu , dyoung@redhat.com Cc: x86@kernel.org, Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Will Deacon , Nicolas Pitre , Chao Fan , "Kirill A. Shutemov" , Ard Biesheuvel , LKML Subject: Re: [PATCHv2] x86/boot/KASLR: skip the specified crashkernel reserved region Message-ID: <20190322083419.GB18740@MiWiFi-R3L-srv> References: <1552450771-8360-1-git-send-email-kernelfans@gmail.com> <20190320002524.GD18740@MiWiFi-R3L-srv> <20190322075259.GA18740@MiWiFi-R3L-srv> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190322075259.GA18740@MiWiFi-R3L-srv> User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.49]); Fri, 22 Mar 2019 08:34:25 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/22/19 at 03:52pm, Baoquan He wrote: > On 03/22/19 at 03:43pm, Pingfan Liu wrote: > > > > +/* parse crashkernel=x@y option */ > > > > +static void mem_avoid_crashkernel_simple(char *option) > > > > > > Chao ever mentioned this, I want to ask again, why does it has to be > > > xxx_simple()? > > > > > Seems that I had replied Chao's question in another email. The naming > > follows the function parse_crashkernel_simple(), as the notes above > ~~~~~~~~~~~~~~~~~~~~~~~~ > > Sorry, I don't get. typo? OK, I misunderstood it. We do have parse_crashkernel_simple() to handle crashkernel=size[@offset] case, to differente with other complicated cases, like crashkernel=size,[high|low], Then I am fine with this naming. Soryy about the noise. By the way, do you think if we should take care of this case: crashkernel=:[,:,...][@offset] It can also specify @offset. Not sure if it's too complicated, you may have a investigation. These two cases have dependency on your crashkernel=X bug fix patch. The current code only allow crashkernel= to reserve under 896MB. I noticed Boris has agreed on the solution. Maybe you can repost a new version based on the discussion. http://lkml.kernel.org/r/1548047768-7656-1-git-send-email-kernelfans@gmail.com [PATCHv7] x86/kdump: bugfix, make the behavior of crashkernel=X consistent with kaslr Thanks Baoquan > > > the definition > > /* > > * That function parses "simple" (old) crashkernel command lines like > > * > > * crashkernel=size[@offset] > > Hmm, should only crashkernel=size@offset be cared? crashkernel=size will > auto finding a place to reserve, and that is after KASLR. > > > * > > * It returns 0 on success and -EINVAL on failure. > > */ > > static int __init parse_crashkernel_simple(char *cmdline, > > > > Do you have alternative suggestion? > > > > > Except of these, patch looks good to me. It's a nice catch, and only > > > need a simple fix based on the current code. > > > > > Thank you for the kindly review. > > > > Regards, > > Pingfan > > > > > Thanks > > > Baoquan > > > > > > > +{ > > > > + unsigned long long crash_size, crash_base; > > > > + char *cur = option; > > > > + > > > > + crash_size = memparse(option, &cur); > > > > + if (option == cur) > > > > + return; > > > > + > > > > + if (*cur == '@') { > > > > + option = cur + 1; > > > > + crash_base = memparse(option, &cur); > > > > + if (option == cur) > > > > + return; > > > > + mem_avoid[MEM_AVOID_CRASHKERNEL].start = crash_base; > > > > + mem_avoid[MEM_AVOID_CRASHKERNEL].size = crash_size; > > > > + } > > > > +} > > > > > > > > static void handle_mem_options(void) > > > > { > > > > @@ -250,7 +270,7 @@ static void handle_mem_options(void) > > > > u64 mem_size; > > > > > > > > if (!strstr(args, "memmap=") && !strstr(args, "mem=") && > > > > - !strstr(args, "hugepages")) > > > > + !strstr(args, "hugepages") && !strstr(args, "crashkernel=")) > > > > return; > > > > > > > > tmp_cmdline = malloc(len + 1); > > > > @@ -286,6 +306,8 @@ static void handle_mem_options(void) > > > > goto out; > > > > > > > > mem_limit = mem_size; > > > > + } else if (strstr(param, "crashkernel")) { > > > > + mem_avoid_crashkernel_simple(val); > > > > } > > > > } > > > > > > > > @@ -414,7 +436,7 @@ static void mem_avoid_init(unsigned long input, unsigned long input_size, > > > > > > > > /* We don't need to set a mapping for setup_data. */ > > > > > > > > - /* Mark the memmap regions we need to avoid */ > > > > + /* Mark the regions we need to avoid */ > > > > handle_mem_options(); > > > > > > > > #ifdef CONFIG_X86_VERBOSE_BOOTUP > > > > -- > > > > 2.7.4 > > > >