From patchwork Mon May 11 16:37:06 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kirill A. Shutemov" X-Patchwork-Id: 226045 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=-14.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING, SIGNED_OFF_BY, SPF_HELO_NONE, 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 7DF61C54E8D for ; Mon, 11 May 2020 16:37:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5F30E2082E for ; Mon, 11 May 2020 16:37:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729895AbgEKQhL (ORCPT ); Mon, 11 May 2020 12:37:11 -0400 Received: from mga12.intel.com ([192.55.52.136]:63012 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729730AbgEKQhK (ORCPT ); Mon, 11 May 2020 12:37:10 -0400 IronPort-SDR: bDuYwScvSgGwSR+ZuHGMyD44IqqdR1Xb2A0Z27lgwTJnzzGCnnHZ4vJzuwOUfuUBW1G3W0bTJd 2ZZlk5NxTecQ== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 May 2020 09:37:09 -0700 IronPort-SDR: sijoHt790+vCFbYL/z9FT3+IdRi7j0VEWF/XF8sCzvQZdM7rtakA6tUCpB/BM08D5J7XD2euE8 037/dj0eI2kQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,380,1583222400"; d="scan'208";a="279837019" Received: from black.fi.intel.com ([10.237.72.28]) by orsmga002.jf.intel.com with ESMTP; 11 May 2020 09:37:07 -0700 Received: by black.fi.intel.com (Postfix, from userid 1000) id 7A70E16B; Mon, 11 May 2020 19:37:06 +0300 (EEST) From: "Kirill A. Shutemov" To: "Hansen, Dave" , Dan Williams , "Kleen, Andi" Cc: dave.hansen@linux.intel.com, linux-drivers-review@eclists.intel.com, "Kirill A. Shutemov" , stable@vger.kernel.org Subject: [PATCH] x86/mm: Fix boot with some memory above MAXMEM Date: Mon, 11 May 2020 19:37:06 +0300 Message-Id: <20200511163706.41619-1-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org A 5-level paging capable machine can have memory above 46-bit in the physical address space. This memory is only addressable in the 5-level paging mode: we don't have enough virtual address space to create direct mapping for such memory in the 4-level paging mode. Currently, we fail boot completely: NULL pointer dereference in subsection_map_init(). Skip creating a memblock for such memory instead and notify user that some memory is not addressable. Signed-off-by: Kirill A. Shutemov Cc: stable@vger.kernel.org # v4.14 --- Tested with a hacked QEMU: https://gist.github.com/kiryl/d45eb54110944ff95e544972d8bdac1d --- arch/x86/kernel/e820.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index c5399e80c59c..022fe1de8940 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -1307,7 +1307,14 @@ void __init e820__memblock_setup(void) if (entry->type != E820_TYPE_RAM && entry->type != E820_TYPE_RESERVED_KERN) continue; - memblock_add(entry->addr, entry->size); + if (entry->addr >= MAXMEM || end >= MAXMEM) + pr_err_once("Some physical memory is not addressable in the paging mode.\n"); + + if (entry->addr >= MAXMEM) + continue; + + end = min_t(u64, end, MAXMEM - 1); + memblock_add(entry->addr, end - entry->addr); } /* Throw away partial pages: */