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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,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 2FA98C43381 for ; Fri, 22 Mar 2019 11:50:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F2CDA20693 for ; Fri, 22 Mar 2019 11:50:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553255448; bh=WXLmifJiRhfuFN8FXmqsTfunqsEOECXfNNN2sjebvmY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=xr3pPgI2XgMNiz9pOYOIIBHh72uaO1nkPYaMtjmlw3xX99zQ619BWkmEYuVGHihV3 gOV4zZIEWk16eJ5fGycfza7B86CdLlyoLoMqVNH4y5jMgk8aSW0Ix32Ow75MdgeTQ8 XEQ26H5mj94lSFMoJStgxuyosg9JIUt1yfkCk3jU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732678AbfCVLur (ORCPT ); Fri, 22 Mar 2019 07:50:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:54588 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732676AbfCVLuq (ORCPT ); Fri, 22 Mar 2019 07:50:46 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 0FFD22082C; Fri, 22 Mar 2019 11:50:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553255445; bh=WXLmifJiRhfuFN8FXmqsTfunqsEOECXfNNN2sjebvmY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=x5uIgH0eBG3iGC2yOJ5LK5FDaGqWuWSIYYSsDzLBr2THxG+H0YNntUx/vZ84VCkfe LvHgm1nbaJddXmI5DD3daiTw0j6iMgoWc072GgnpRhq+HLrw47KnKBAD1nmept+htG fuaEnJM4/SuZwxsgJ+BsvRBnLqN5Vb+wBRlPSVgM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Martin Schwidefsky Subject: [PATCH 4.14 093/183] s390/setup: fix early warning messages Date: Fri, 22 Mar 2019 12:15:21 +0100 Message-Id: <20190322111248.454011621@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190322111241.819468003@linuxfoundation.org> References: <20190322111241.819468003@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Martin Schwidefsky commit 8727638426b0aea59d7f904ad8ddf483f9234f88 upstream. The setup_lowcore() function creates a new prefix page for the boot CPU. The PSW mask for the system_call, external interrupt, i/o interrupt and the program check handler have the DAT bit set in this new prefix page. At the time setup_lowcore is called the system still runs without virtual address translation, the paging_init() function creates the kernel page table and loads the CR13 with the kernel ASCE. Any code between setup_lowcore() and the end of paging_init() that has a BUG or WARN statement will create a program check that can not be handled correctly as there is no kernel page table yet. To allow early WARN statements initially setup the lowcore with DAT off and set the DAT bit only after paging_init() has completed. Cc: stable@vger.kernel.org Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman --- arch/s390/kernel/setup.c | 32 +++++++++++++++++++++++--------- 1 file changed, 23 insertions(+), 9 deletions(-) --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -300,7 +300,7 @@ early_param("vmalloc", parse_vmalloc); void *restart_stack __section(.data); -static void __init setup_lowcore(void) +static void __init setup_lowcore_dat_off(void) { struct lowcore *lc; @@ -311,19 +311,16 @@ static void __init setup_lowcore(void) lc = memblock_virt_alloc_low(sizeof(*lc), sizeof(*lc)); lc->restart_psw.mask = PSW_KERNEL_BITS; lc->restart_psw.addr = (unsigned long) restart_int_handler; - lc->external_new_psw.mask = PSW_KERNEL_BITS | - PSW_MASK_DAT | PSW_MASK_MCHECK; + lc->external_new_psw.mask = PSW_KERNEL_BITS | PSW_MASK_MCHECK; lc->external_new_psw.addr = (unsigned long) ext_int_handler; lc->svc_new_psw.mask = PSW_KERNEL_BITS | - PSW_MASK_DAT | PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK; + PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK; lc->svc_new_psw.addr = (unsigned long) system_call; - lc->program_new_psw.mask = PSW_KERNEL_BITS | - PSW_MASK_DAT | PSW_MASK_MCHECK; + lc->program_new_psw.mask = PSW_KERNEL_BITS | PSW_MASK_MCHECK; lc->program_new_psw.addr = (unsigned long) pgm_check_handler; lc->mcck_new_psw.mask = PSW_KERNEL_BITS; lc->mcck_new_psw.addr = (unsigned long) mcck_int_handler; - lc->io_new_psw.mask = PSW_KERNEL_BITS | - PSW_MASK_DAT | PSW_MASK_MCHECK; + lc->io_new_psw.mask = PSW_KERNEL_BITS | PSW_MASK_MCHECK; lc->io_new_psw.addr = (unsigned long) io_int_handler; lc->clock_comparator = clock_comparator_max; lc->kernel_stack = ((unsigned long) &init_thread_union) @@ -391,6 +388,17 @@ static void __init setup_lowcore(void) lowcore_ptr[0] = lc; } +static void __init setup_lowcore_dat_on(void) +{ + struct lowcore *lc; + + lc = lowcore_ptr[0]; + lc->external_new_psw.mask |= PSW_MASK_DAT; + lc->svc_new_psw.mask |= PSW_MASK_DAT; + lc->program_new_psw.mask |= PSW_MASK_DAT; + lc->io_new_psw.mask |= PSW_MASK_DAT; +} + static struct resource code_resource = { .name = "Kernel code", .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, @@ -948,7 +956,7 @@ void __init setup_arch(char **cmdline_p) #endif setup_resources(); - setup_lowcore(); + setup_lowcore_dat_off(); smp_fill_possible_mask(); cpu_detect_mhz_feature(); cpu_init(); @@ -961,6 +969,12 @@ void __init setup_arch(char **cmdline_p) */ paging_init(); + /* + * After paging_init created the kernel page table, the new PSWs + * in lowcore can now run with DAT enabled. + */ + setup_lowcore_dat_on(); + /* Setup default console */ conmode_default(); set_preferred_console();