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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS autolearn=no 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 20DD2C4708A for ; Wed, 26 May 2021 20:49:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0012C613CA for ; Wed, 26 May 2021 20:49:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233646AbhEZUv0 (ORCPT ); Wed, 26 May 2021 16:51:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:56366 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233669AbhEZUvS (ORCPT ); Wed, 26 May 2021 16:51:18 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0F4E0611BE; Wed, 26 May 2021 20:49:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1622062183; bh=aG3UINtyIudcCr1jcShtuROgiwkLr+yC67i/e+rJ130=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=OQwH8Nh0p62kPnQVnKw9Qkv+XdO/rDpNJhqsOhVin5GIOJh/KcfPrFp+TCZ0SQxtT HIKBj/oMDfISR9tnVTIv3uFVdY2pchbUAk+iU7zkSYs9T5s+IHs5kuMj9oX5DSNDO7 15hbwX00Wy9vVEFS81Q+EEpxkZp9BzNquTJXj8EU= Date: Wed, 26 May 2021 13:49:42 -0700 From: Andrew Morton To: Thomas Bogendoerfer Cc: linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, =?UTF-8?Q?=E5=91=A8=E7=90=B0=E6=9D=B0?= Subject: Re: [PATCH] Revert "MIPS: make userspace mapping young by default" Message-Id: <20210526134942.2bf26d5cf5a9243583aec131@linux-foundation.org> In-Reply-To: <20210526094335.92948-1-tsbogend@alpha.franken.de> References: <20210526094335.92948-1-tsbogend@alpha.franken.de> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 26 May 2021 11:43:35 +0200 Thomas Bogendoerfer wrote: > This reverts commit f685a533a7fab35c5d069dcd663f59c8e4171a75. > > MIPS cache flush logic needs to know whether the mapping was already > established to decide how to flush caches. This is done by checking the > valid bit in the PTE. The commit above breaks this logic by setting > the valid in the PTE in new mappings, which causes kernel crashes. Thanks. I added Fixes: f685a533a7f ("MIPS: make userspace mapping young by default") Cc: