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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, 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 C0D6EC4338F for ; Mon, 2 Aug 2021 15:19:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A5B5460FD8 for ; Mon, 2 Aug 2021 15:19:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234787AbhHBPTi (ORCPT ); Mon, 2 Aug 2021 11:19:38 -0400 Received: from pegase2.c-s.fr ([93.17.235.10]:35331 "EHLO pegase2.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234233AbhHBPTf (ORCPT ); Mon, 2 Aug 2021 11:19:35 -0400 Received: from localhost (mailhub3.si.c-s.fr [172.26.127.67]) by localhost (Postfix) with ESMTP id 4GdhW0386Pz9sVF; Mon, 2 Aug 2021 17:19:24 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from pegase2.c-s.fr ([172.26.127.65]) by localhost (pegase2.c-s.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 2QnmngloUx-q; Mon, 2 Aug 2021 17:19:24 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase2.c-s.fr (Postfix) with ESMTP id 4GdhW02BD3z9sV7; Mon, 2 Aug 2021 17:19:24 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 303AA8B776; Mon, 2 Aug 2021 17:19:24 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id yCPwypI_1JZp; Mon, 2 Aug 2021 17:19:24 +0200 (CEST) Received: from PO20335.IDSI0.si.c-s.fr (unknown [172.25.230.107]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 089A38B763; Mon, 2 Aug 2021 17:19:23 +0200 (CEST) Subject: Re: [PATCH v3 31/41] powerpc/32: Dismantle EXC_XFER_STD/LITE/TEMPLATE To: Finn Thain Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Nick Piggin , Michael Ellerman , Paul Mackerras , Benjamin Herrenschmidt , Stan Johnson References: <666e3ab4-372-27c2-4621-7cc3933756dd@linux-m68k.org> <20210731173954.Horde.fV2Xkw7-sxjG0DUcZ_JO_g3@messagerie.c-s.fr> <1d601b7c-1e39-e372-39a5-e1e98e56e2a5@linux-m68k.org> From: LEROY Christophe Message-ID: <9b64dde3-6ebd-b446-41d9-61e8cb0d8c39@csgroup.eu> Date: Mon, 2 Aug 2021 17:19:23 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <1d601b7c-1e39-e372-39a5-e1e98e56e2a5@linux-m68k.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Language: fr-FR Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 01/08/2021 à 03:21, Finn Thain a écrit : > On Sat, 31 Jul 2021, Christophe Leroy wrote: > >>> >>> Stan Johnson contacted me about a regression in mainline that he >>> observed on his G3 Powerbooks. Using 'git bisect' we determined that >>> this patch was the cause of the regression, i.e. commit 4c0104a83fc3 >>> ("powerpc/32: Dismantle EXC_XFER_STD/LITE/TEMPLATE"). >>> >>> When testing 4c0104a83fc and all subsequent builds, various user >>> processes were liable to segfault. Here is the console log that Stan >>> provided: >> >> Hi, i will be able to look at that more in details next week, however I >> have a few preliminary qurstions. >> >> Can you reliabily reproduce the problem with the said commit, and can >> you reliabily run without problem with the parent commit ? > > Yes and yes. (I already asked Stan to establish those things before I > contacted the list.) I think I found the problem with that commit. Can you retry with the following change: diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S index 0a3d7d4a9ec4..a294103a91a1 100644 --- a/arch/powerpc/kernel/head_book3s_32.S +++ b/arch/powerpc/kernel/head_book3s_32.S @@ -299,7 +299,7 @@ ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_HPTE_TABLE) EXCEPTION_PROLOG_1 EXCEPTION_PROLOG_2 0x300 DataAccess handle_dar_dsisr=1 prepare_transfer_to_handler - lwz r5, _DSISR(r11) + lwz r5, _DSISR(r1) andis. r0, r5, DSISR_DABRMATCH@h bne- 1f bl do_page_fault --- Thanks Christophe