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=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 C432AC55178 for ; Tue, 3 Nov 2020 20:49:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 89E9822404 for ; Tue, 3 Nov 2020 20:49:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604436543; bh=Fpydzvaweo0Y+3y3QPw0J6GRZc5CxqW6NB98jym14QE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=tC16bE3R2oULKWKm61DeN3eiykBXzaGe87QZFV1S8Wkv/nKup5z35GKQ9vZH/6fIH vmbNdDyKMhVrUYd7zbBWA9Yfhoa08E6pg5tlS4ZPWP7i/wg2h/KX05Fbv2IZGFDjA2 lBYs1uyi0F8Smgp2nBsSomLlgDiA7x1PgcLCkC/o= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731692AbgKCUtC (ORCPT ); Tue, 3 Nov 2020 15:49:02 -0500 Received: from mail.kernel.org ([198.145.29.99]:41320 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731682AbgKCUtA (ORCPT ); Tue, 3 Nov 2020 15:49:00 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5C48C20719; Tue, 3 Nov 2020 20:48:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604436539; bh=Fpydzvaweo0Y+3y3QPw0J6GRZc5CxqW6NB98jym14QE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sAAV6PGBPrd6rEBpYil9M1JsEwpZKR3Vcg96fsiGskBmXdaH/DAmulpRd2Sb6RSQ+ 96Vkkfbz3EFDuxssVaGOWyiyHD61nQ8F9BsF9HTbOJDuGqbrLA9WIPIO9Pt7xKNSvg Ht5/Ocpug+9gevr8/TQD5VcDjyYD+mjquAPXXRZM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Christophe Leroy , Michael Ellerman Subject: [PATCH 5.9 293/391] powerpc/32: Fix vmap stack - Do not activate MMU before reading task struct Date: Tue, 3 Nov 2020 21:35:44 +0100 Message-Id: <20201103203406.843607550@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201103203348.153465465@linuxfoundation.org> References: <20201103203348.153465465@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Christophe Leroy commit c118c7303ad528be8ff2aea8cd1ee15452c763f0 upstream. We need r1 to be properly set before activating MMU, so reading task_struct->stack must be done with MMU off. This means we need an additional register to play with MSR bits while r11 now points to the stack. For that, move r10 back to CR (As is already done for hash MMU) and use r10. We still don't have r1 correct yet when we activate MMU. It is done in following patch. Fixes: 028474876f47 ("powerpc/32: prepare for CONFIG_VMAP_STACK") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/a027d447022a006c9c4958ac734128e577a3c5c1.1599486108.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/kernel/head_32.S | 6 ------ arch/powerpc/kernel/head_32.h | 31 ++++++------------------------- 2 files changed, 6 insertions(+), 31 deletions(-) --- a/arch/powerpc/kernel/head_32.S +++ b/arch/powerpc/kernel/head_32.S @@ -274,14 +274,8 @@ __secondary_hold_acknowledge: DO_KVM 0x200 MachineCheck: EXCEPTION_PROLOG_0 -#ifdef CONFIG_VMAP_STACK - li r11, MSR_KERNEL & ~(MSR_IR | MSR_RI) /* can take DTLB miss */ - mtmsr r11 - isync -#endif #ifdef CONFIG_PPC_CHRP mfspr r11, SPRN_SPRG_THREAD - tovirt_vmstack r11, r11 lwz r11, RTAS_SP(r11) cmpwi cr1, r11, 0 bne cr1, 7f --- a/arch/powerpc/kernel/head_32.h +++ b/arch/powerpc/kernel/head_32.h @@ -39,24 +39,13 @@ .endm .macro EXCEPTION_PROLOG_1 for_rtas=0 -#ifdef CONFIG_VMAP_STACK - .ifeq \for_rtas - li r11, MSR_KERNEL & ~(MSR_IR | MSR_RI) /* can take DTLB miss */ - mtmsr r11 - isync - .endif subi r11, r1, INT_FRAME_SIZE /* use r1 if kernel */ -#else - tophys(r11,r1) /* use tophys(r1) if kernel */ - subi r11, r11, INT_FRAME_SIZE /* alloc exc. frame */ -#endif beq 1f mfspr r11,SPRN_SPRG_THREAD - tovirt_vmstack r11, r11 lwz r11,TASK_STACK-THREAD(r11) addi r11, r11, THREAD_SIZE - INT_FRAME_SIZE - tophys_novmstack r11, r11 1: + tophys_novmstack r11, r11 #ifdef CONFIG_VMAP_STACK mtcrf 0x7f, r11 bt 32 - THREAD_ALIGN_SHIFT, stack_overflow @@ -64,12 +53,11 @@ .endm .macro EXCEPTION_PROLOG_2 handle_dar_dsisr=0 -#if defined(CONFIG_VMAP_STACK) && defined(CONFIG_PPC_BOOK3S) -BEGIN_MMU_FTR_SECTION +#ifdef CONFIG_VMAP_STACK mtcr r10 -FTR_SECTION_ELSE - stw r10, _CCR(r11) -ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_HPTE_TABLE) + li r10, MSR_KERNEL & ~(MSR_IR | MSR_RI) /* can take DTLB miss */ + mtmsr r10 + isync #else stw r10,_CCR(r11) /* save registers */ #endif @@ -77,11 +65,9 @@ ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_HP stw r12,GPR12(r11) stw r9,GPR9(r11) stw r10,GPR10(r11) -#if defined(CONFIG_VMAP_STACK) && defined(CONFIG_PPC_BOOK3S) -BEGIN_MMU_FTR_SECTION +#ifdef CONFIG_VMAP_STACK mfcr r10 stw r10, _CCR(r11) -END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE) #endif mfspr r12,SPRN_SPRG_SCRATCH1 stw r12,GPR11(r11) @@ -97,11 +83,7 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_T stw r10, _DSISR(r11) .endif lwz r9, SRR1(r12) -#if defined(CONFIG_VMAP_STACK) && defined(CONFIG_PPC_BOOK3S) -BEGIN_MMU_FTR_SECTION andi. r10, r9, MSR_PR -END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE) -#endif lwz r12, SRR0(r12) #else mfspr r12,SPRN_SRR0 @@ -328,7 +310,6 @@ label: #ifdef CONFIG_VMAP_STACK #ifdef CONFIG_SMP mfspr r11, SPRN_SPRG_THREAD - tovirt(r11, r11) lwz r11, TASK_CPU - THREAD(r11) slwi r11, r11, 3 addis r11, r11, emergency_ctx@ha