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,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 0AD98C43381 for ; Fri, 22 Mar 2019 12:04:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C1FE221934 for ; Fri, 22 Mar 2019 12:04:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553256262; bh=QE4w78cd72a5MUU9gTRFx/PRQctUfmH1mr81UcQXbjc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=GtTuItd1m8RBR1RkRFVzB+O1QY7XNHkCZ9otjTv4a1FeUWCquwiVBlcud9j66or3o 2ysvFt6Hax/lLBmM7xl/qQNrjRuTxFZETv70bhVuksIe14GCDslA8rJYzPhcLMk6Fx 68Ix5a5i10JwnkjW8kQEiy5e/fRP4lK41YF+HDTA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388664AbfCVMEV (ORCPT ); Fri, 22 Mar 2019 08:04:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:42752 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388316AbfCVMES (ORCPT ); Fri, 22 Mar 2019 08:04:18 -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 7FE362082C; Fri, 22 Mar 2019 12:04:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553256258; bh=QE4w78cd72a5MUU9gTRFx/PRQctUfmH1mr81UcQXbjc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uQKC5QypfJNJvsFFIWuwXBPaPM31NtG075T7QkyTfOOEKUvpiNw5yHB1l/nhUZuZS Q8c4jWAxskRfX4RDEGbVHFGdvwLsGzna4OFUuPOrRibuYkLYFZZzap+FOdJToFJv5A LqyGdFYplHbeQyTH9c/+t59YIph0syOOEh+fkxbE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Martin Schwidefsky Subject: [PATCH 4.19 156/280] s390/setup: fix early warning messages Date: Fri, 22 Mar 2019 12:15:09 +0100 Message-Id: <20190322111321.410542569@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190322111306.356185024@linuxfoundation.org> References: <20190322111306.356185024@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: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.19-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 @@ -303,7 +303,7 @@ 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; @@ -314,19 +314,16 @@ 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) @@ -388,6 +385,17 @@ 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, @@ -946,7 +954,7 @@ 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(); @@ -959,6 +967,12 @@ 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();