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 998D4ECAAD3 for ; Thu, 1 Sep 2022 12:53:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232405AbiIAMx3 (ORCPT ); Thu, 1 Sep 2022 08:53:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43130 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229555AbiIAMx1 (ORCPT ); Thu, 1 Sep 2022 08:53:27 -0400 Received: from out28-194.mail.aliyun.com (out28-194.mail.aliyun.com [115.124.28.194]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0C42DB7C9 for ; Thu, 1 Sep 2022 05:53:23 -0700 (PDT) X-Alimail-AntiSpam: AC=CONTINUE;BC=0.07441293|-1;CH=green;DM=|CONTINUE|false|;DS=CONTINUE|ham_news_journal|0.0137863-0.000745102-0.985469;FP=0|0|0|0|0|-1|-1|-1;HT=ay29a033018047190;MF=victor@allwinnertech.com;NM=1;PH=DS;RN=11;RT=11;SR=0;TI=SMTPD_---.P5JnUS1_1662036799; Received: from 192.168.220.144(mailfrom:victor@allwinnertech.com fp:SMTPD_---.P5JnUS1_1662036799) by smtp.aliyun-inc.com; Thu, 01 Sep 2022 20:53:20 +0800 Message-ID: <6c14e174-cdb6-c1fc-58cc-d579111d2328@allwinnertech.com> Date: Thu, 1 Sep 2022 20:53:19 +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 From: Victor Hassan 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> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022/8/31 20:37, Victor Hassan wrote: > 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 Hi Marek, Sorry, didn't take into account that console_drivers is NULL when earlycon is not used. Here is the patch-v2. Please review: diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index a49f0b9..a240f38 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include @@ -1730,6 +1731,10 @@ pmd_clear(fixmap_pmd(va)); local_flush_tlb_kernel_page(va); +#ifdef CONFIG_FIX_EARLYCON_MEM + if (console_drivers) + console_stop(console_drivers); +#endif for (i = 0; i < __end_of_permanent_fixed_addresses; i++) { pte_t *pte; struct map_desc map; @@ -1748,6 +1753,10 @@ create_mapping(&map); } +#ifdef CONFIG_FIX_EARLYCON_MEM + if (console_drivers) + console_start(console_drivers); +#endif } BTW, should I resend the patch-v2 through the site (https://www.armlinux.org.uk/developer/patches/add.php), or should I send the patch-v2 through E-mail to Linux-Mainline? Thanks you. Regards, Victor