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 4534EECAAD4 for ; Wed, 31 Aug 2022 12:37:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229978AbiHaMhq (ORCPT ); Wed, 31 Aug 2022 08:37:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33640 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229456AbiHaMho (ORCPT ); Wed, 31 Aug 2022 08:37:44 -0400 Received: from out28-148.mail.aliyun.com (out28-148.mail.aliyun.com [115.124.28.148]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CC2F0167D9 for ; Wed, 31 Aug 2022 05:37:42 -0700 (PDT) X-Alimail-AntiSpam: AC=CONTINUE;BC=0.07722721|-1;CH=green;DM=|CONTINUE|false|;DS=CONTINUE|ham_news_journal|0.0675243-0.00153387-0.930942;FP=0|0|0|0|0|-1|-1|-1;HT=ay29a033018047198;MF=victor@allwinnertech.com;NM=1;PH=DS;RN=11;RT=11;SR=0;TI=SMTPD_---.P4QJDlq_1661949456; Received: from 192.168.220.136(mailfrom:victor@allwinnertech.com fp:SMTPD_---.P4QJDlq_1661949456) by smtp.aliyun-inc.com; Wed, 31 Aug 2022 20:37:39 +0800 Message-ID: Date: Wed, 31 Aug 2022 20:37:36 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.9.0 Subject: Re: [PATCH] ARM: mmu: fix access to illegal address when using earlycon & memblock=debug Content-Language: en-US To: Marek Szyprowski , linux@armlinux.org.uk, rmk+kernel@armlinux.org.uk, linus.walleij@linaro.org, yanfei.xu@windriver.com, ardb@kernel.org, tglx@linutronix.de, mirq-linux@rere.qmqm.pl, arnd@arndb.de Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20220316023356.120595-1-victor@allwinnertech.com> <9a425a51-9460-6c4d-e331-5cd5873f8a43@samsung.com> From: Victor Hassan In-Reply-To: <9a425a51-9460-6c4d-e331-5cd5873f8a43@samsung.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/31/2022 7:52 PM, Marek Szyprowski wrote: > Hi Victor, > > On 16.03.2022 03:33, Victor Hassan wrote: >> earlycon uses fixmap to create a memory map, >> So we need to close earlycon before closing fixmap, >> otherwise printk will access illegal addresses. >> After creating a new memory map, we open earlycon again. >> >> Signed-off-by: Victor Hassan > > This patch landed in linux next-20220831 as commit a76886d117cb ("ARM: > 9223/1: mmu: fix access to illegal address when using earlycon & > memblock=debug"). Unfortunately it breaks booting of all my test boards > which *do not* use earlycon. It can be easily reproduced even with QEMU. > > With kernel compiled from multi_v7_defconfig the following setup boots: > > $ qemu-system-arm -nographic -kernel arch/arm/boot/zImage -append > "console=ttyAMA0 earlycon" -M virt -smp 2 -m 512 > > while this one doesn't: > > $ qemu-system-arm -nographic -kernel arch/arm/boot/zImage -append > "console=ttyAMA0" -M virt -smp 2 -m 512 > > >> --- >> arch/arm/mm/mmu.c | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c >> index 274e4f73fd33..f3511f07a7d0 100644 >> --- a/arch/arm/mm/mmu.c >> +++ b/arch/arm/mm/mmu.c >> @@ -14,6 +14,7 @@ >> #include >> #include >> #include >> +#include >> >> #include >> #include >> @@ -1695,6 +1696,9 @@ static void __init early_fixmap_shutdown(void) >> pmd_clear(fixmap_pmd(va)); >> local_flush_tlb_kernel_page(va); >> >> +#ifdef CONFIG_FIX_EARLYCON_MEM >> + console_stop(console_drivers); >> +#endif >> for (i = 0; i < __end_of_permanent_fixed_addresses; i++) { >> pte_t *pte; >> struct map_desc map; >> @@ -1713,6 +1717,9 @@ static void __init early_fixmap_shutdown(void) >> >> create_mapping(&map); >> } >> +#ifdef CONFIG_FIX_EARLYCON_MEM >> + console_start(console_drivers); >> +#endif >> } >> >> /* > > Best regards Dear Marek, Thank you for the notice. I'll figure it out and feed back to you as soon as possible. Regards, Victor