Received: by 2002:a05:6a10:9e8c:0:0:0:0 with SMTP id y12csp693034pxx; Wed, 28 Oct 2020 14:41:34 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyyCwdbO4bCVXXnvp6YiInG3p4SU+aDEJKL1YwFJDscIbf44+zHsa6GDhnzFCibSKNN1bDK X-Received: by 2002:a17:906:f0d8:: with SMTP id dk24mr1081292ejb.492.1603921294675; Wed, 28 Oct 2020 14:41:34 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1603921294; cv=none; d=google.com; s=arc-20160816; b=xBEQpTf9F1ZbFJMuHMileK0Ob5fKJyrj8fDrQ9jd0a3HSGE73w4dvTlzhTL8U/YNqP CQp7g3ZYXYD7mAqzzWLKQj52Put2tSf8EUzhvcXf2vSEv8tQ61cfVgjkZXO9MAiOBlSP Df5fpXVX2VEVFJbPV7uq/yvJFvrhyDEzcjTroTGfTZRRbQwFLpZzQrrUAHk3j2nfGm8P d19HL4EQz83xiXLehmEI0jcTZjBOhpKkvfSCYSDwwKDT25ZeEoWdgAvVbXlmDZPz2bRa 6actDiXR+3KmBjmLgNuGWovZ4b/lab49LhoO07u79fSEgyejh/rObv/nzmATTfihhv5Q bBVg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:mime-version:user-agent:message-id:in-reply-to :date:references:subject:cc:to:from; bh=Z1t8yPTAKOjYQNWKJyzJvsXygTkyRe3B/wB7n4YrFsE=; b=jXngyLcCUuIX2oQSXHOG6HH6l5qCdc+hjgH9/DskGgWaoEO70q2OBxVhM54jKgDd7V 0b5zvw9Z+MzSi3pKLMWfNBDQloDgV4XOM0/5eVOu4nXR9aj60yGfvNV30Sdlh5qdFgOg tx4hUApv95bSoYtGAxCa2pgctO9hrl7LmzfTyBYPMrNCUwD8MYW2GbFYflvXsmdHpDYA KHPuUxIDfSS2Pzw9pk9mALYP0XwOfv94yJnwU0UN/p6cpV/hNQI1fDobvTJWQ3gOu9cs yuPY73Qfe/wrpoppplvLyJbzSmDsDGGmFZixYXvgymuA2c57A0LACtJpIifFpCZdL1MK +mOQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id y11si422600ejp.53.2020.10.28.14.41.09; Wed, 28 Oct 2020 14:41:34 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726110AbgJ1Bie (ORCPT + 99 others); Tue, 27 Oct 2020 21:38:34 -0400 Received: from mail-out.m-online.net ([212.18.0.9]:42060 "EHLO mail-out.m-online.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1832999AbgJ0X0V (ORCPT ); Tue, 27 Oct 2020 19:26:21 -0400 Received: from frontend01.mail.m-online.net (unknown [192.168.8.182]) by mail-out.m-online.net (Postfix) with ESMTP id 4CLSWZ43TGz1qrf4; Wed, 28 Oct 2020 00:26:18 +0100 (CET) Received: from localhost (dynscan1.mnet-online.de [192.168.6.70]) by mail.m-online.net (Postfix) with ESMTP id 4CLSWZ2sGWz1qxh0; Wed, 28 Oct 2020 00:26:18 +0100 (CET) X-Virus-Scanned: amavisd-new at mnet-online.de Received: from mail.mnet-online.de ([192.168.8.182]) by localhost (dynscan1.mail.m-online.net [192.168.6.70]) (amavisd-new, port 10024) with ESMTP id 5rzp0rheSnFs; Wed, 28 Oct 2020 00:26:17 +0100 (CET) X-Auth-Info: RS9aI4PlyTCBHGWJrSWEDVriYnK+Ge5YcPCqkwJrXrVC6IGL/CAq2pX641Nc5O6k Received: from igel.home (ppp-46-244-161-64.dynamic.mnet-online.de [46.244.161.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.mnet-online.de (Postfix) with ESMTPSA; Wed, 28 Oct 2020 00:26:17 +0100 (CET) Received: by igel.home (Postfix, from userid 1000) id E56742C2B09; Wed, 28 Oct 2020 00:26:16 +0100 (CET) From: Andreas Schwab To: Christophe Leroy Cc: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/3] powerpc/uaccess: Switch __put_user_size_allowed() to __put_user_asm_goto() References: <94ba5a5138f99522e1562dbcdb38d31aa790dc89.1599216721.git.christophe.leroy__44535.5968013004$1599217383$gmane$org@csgroup.eu> X-Yow: Here we are in America... when do we collect unemployment? Date: Wed, 28 Oct 2020 00:26:16 +0100 In-Reply-To: <94ba5a5138f99522e1562dbcdb38d31aa790dc89.1599216721.git.christophe.leroy__44535.5968013004$1599217383$gmane$org@csgroup.eu> (Christophe Leroy's message of "Fri, 4 Sep 2020 11:01:30 +0000 (UTC)") Message-ID: <87mu079ron.fsf@igel.home> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sep 04 2020, Christophe Leroy wrote: > __put_user_asm_goto() provides more flexibility to GCC and avoids using > a local variable to tell if the write succeeded or not. > GCC can then avoid implementing a cmp in the fast path. That breaks CLONE_CHILD_SETTID. I'm getting an assertion failure in __libc_fork (THREAD_GETMEM (self, tid) != ppid). Andreas. -- Andreas Schwab, schwab@linux-m68k.org GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1 "And now for something completely different."