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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 50F71C43219 for ; Wed, 1 May 2019 00:55:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2B33B20866 for ; Wed, 1 May 2019 00:55:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727648AbfEAAzv (ORCPT ); Tue, 30 Apr 2019 20:55:51 -0400 Received: from bilbo.ozlabs.org ([203.11.71.1]:57909 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727553AbfEAAzv (ORCPT ); Tue, 30 Apr 2019 20:55:51 -0400 Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 44v0Lp6GJ9z9s3l; Wed, 1 May 2019 10:55:46 +1000 (AEST) From: Michael Ellerman To: Christophe Leroy , Benjamin Herrenschmidt , Paul Mackerras , Serge Belyshev , Segher Boessenkool Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH v2] powerpc/32s: fix BATs setting with CONFIG_STRICT_KERNEL_RWX In-Reply-To: <09733bd9d90f2ab9dfee9838442e0bea01df194d.1556640535.git.christophe.leroy@c-s.fr> References: <09733bd9d90f2ab9dfee9838442e0bea01df194d.1556640535.git.christophe.leroy@c-s.fr> Date: Wed, 01 May 2019 10:55:46 +1000 Message-ID: <878svrat7x.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Christophe Leroy writes: > Serge reported some crashes with CONFIG_STRICT_KERNEL_RWX enabled > on a book3s32 machine. > > Analysis shows two issues: > - BATs addresses and sizes are not properly aligned. > - There is a gap between the last address covered by BATs and the > first address covered by pages. > > Memory mapped with DBATs: > 0: 0xc0000000-0xc07fffff 0x00000000 Kernel RO coherent > 1: 0xc0800000-0xc0bfffff 0x00800000 Kernel RO coherent > 2: 0xc0c00000-0xc13fffff 0x00c00000 Kernel RW coherent > 3: 0xc1400000-0xc23fffff 0x01400000 Kernel RW coherent > 4: 0xc2400000-0xc43fffff 0x02400000 Kernel RW coherent > 5: 0xc4400000-0xc83fffff 0x04400000 Kernel RW coherent > 6: 0xc8400000-0xd03fffff 0x08400000 Kernel RW coherent > 7: 0xd0400000-0xe03fffff 0x10400000 Kernel RW coherent > > Memory mapped with pages: > 0xe1000000-0xefffffff 0x21000000 240M rw present dirty accessed > > This patch fixes both issues. With the patch, we get the following > which is as expected: > > Memory mapped with DBATs: > 0: 0xc0000000-0xc07fffff 0x00000000 Kernel RO coherent > 1: 0xc0800000-0xc0bfffff 0x00800000 Kernel RO coherent > 2: 0xc0c00000-0xc0ffffff 0x00c00000 Kernel RW coherent > 3: 0xc1000000-0xc1ffffff 0x01000000 Kernel RW coherent > 4: 0xc2000000-0xc3ffffff 0x02000000 Kernel RW coherent > 5: 0xc4000000-0xc7ffffff 0x04000000 Kernel RW coherent > 6: 0xc8000000-0xcfffffff 0x08000000 Kernel RW coherent > 7: 0xd0000000-0xdfffffff 0x10000000 Kernel RW coherent > > Memory mapped with pages: > 0xe0000000-0xefffffff 0x20000000 256M rw present dirty accessed > > Reported-by: Serge Belyshev > Fixes: 63b2bc619565 ("powerpc/mm/32s: Use BATs for STRICT_KERNEL_RWX") > Cc: stable@vger.kernel.org I could probably still get this into v5.1 if you're confident it's a good fix. cheers