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=-8.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 B4EA2C31E47 for ; Wed, 12 Jun 2019 04:59:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9711520896 for ; Wed, 12 Jun 2019 04:59:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730456AbfFLE7N (ORCPT ); Wed, 12 Jun 2019 00:59:13 -0400 Received: from ozlabs.org ([203.11.71.1]:40361 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730393AbfFLE7M (ORCPT ); Wed, 12 Jun 2019 00:59:12 -0400 Received: by ozlabs.org (Postfix, from userid 1034) id 45NvmH0kL6z9sBr; Wed, 12 Jun 2019 14:59:10 +1000 (AEST) X-powerpc-patch-notification: thanks X-powerpc-patch-commit: c21f5a9ed85ca3e914ca11f421677ae9ae0d04b0 X-Patchwork-Hint: ignore In-Reply-To: <90d30adb0943a11ab127808c03229ba657478df4.1559566521.git.christophe.leroy@c-s.fr> To: Christophe Leroy , Benjamin Herrenschmidt , Paul Mackerras , Mathieu Malaterre From: Michael Ellerman Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] powerpc/32s: fix booting with CONFIG_PPC_EARLY_DEBUG_BOOTX Message-Id: <45NvmH0kL6z9sBr@ozlabs.org> Date: Wed, 12 Jun 2019 14:59:10 +1000 (AEST) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2019-06-03 at 13:00:51 UTC, Christophe Leroy wrote: > When booting through OF, setup_disp_bat() does nothing because > disp_BAT are not set. By change, it used to work because BOOTX > buffer is mapped 1:1 at address 0x81000000 by the bootloader, and > btext_setup_display() sets virt addr same as phys addr. > > But since commit 215b823707ce ("powerpc/32s: set up an early static > hash table for KASAN."), a temporary page table overrides the > bootloader mapping. > > This 0x81000000 is also problematic with the newly implemented > Kernel Userspace Access Protection (KUAP) because it is within user > address space. > > This patch fixes those issues by properly setting disp_BAT through > a call to btext_prepare_BAT(), allowing setup_disp_bat() to > properly setup BAT3 for early bootx screen buffer access. > > Reported-by: Mathieu Malaterre > Fixes: 215b823707ce ("powerpc/32s: set up an early static hash table for KASAN.") > Signed-off-by: Christophe Leroy > Tested-by: Mathieu Malaterre Applied to powerpc fixes, thanks. https://git.kernel.org/powerpc/c/c21f5a9ed85ca3e914ca11f421677ae9 cheers