From patchwork Wed Sep 6 07:39:01 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Adrian Hunter X-Patchwork-Id: 720700 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AD0C4EB8FA5 for ; Wed, 6 Sep 2023 07:39:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233902AbjIFHje (ORCPT ); Wed, 6 Sep 2023 03:39:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60028 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233896AbjIFHjd (ORCPT ); Wed, 6 Sep 2023 03:39:33 -0400 Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.120]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8AE97E64; Wed, 6 Sep 2023 00:39:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1693985969; x=1725521969; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=hCFPnesd773Gv+sIsXwxuNHU7U7Bs8P2FxvU4qByuSM=; b=g0CHtJZhrNgF7OKEUSNtmuSGYuZH5Ox8IysJ9Th981FngrpLjy4fYyVP T9MODacwYflplKZDKyC1V7fRTuH15PlSF4Nww2qDk+aVgYXED/dP7QYD6 m8RMO2trK0vGnhpXr+5V3tp1PRQxHQILUEkTn8T6flhP6fHTimIG50spk on2kJeK+dsTwQApZaH5H2QmL+mP11qtH/yKdwVgfLZNasbS955YU4B9A8 3X8pYaCp6+LNHVEn44uzkgkuf8QDctwrLLJBJ3Sqt/CcLVLiDExlO8EyL fSyRSFXcLpFD6dm1rS9KuLd3x8KMtOUUtDm83PCYBKxc9YsFQ3bLg2Kpq w==; X-IronPort-AV: E=McAfee;i="6600,9927,10824"; a="375898463" X-IronPort-AV: E=Sophos;i="6.02,231,1688454000"; d="scan'208";a="375898463" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Sep 2023 00:39:29 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10824"; a="988133794" X-IronPort-AV: E=Sophos;i="6.02,231,1688454000"; d="scan'208";a="988133794" Received: from ahunter6-mobl1.ger.corp.intel.com (HELO ahunter-VirtualBox.home\044ger.corp.intel.com) ([10.252.60.154]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Sep 2023 00:39:24 -0700 From: Adrian Hunter To: "Kirill A. Shutemov" , Borislav Petkov , Andrew Morton Cc: Dave Hansen , Vlastimil Babka , Mike Rapoport , Lorenzo Stoakes , Tom Lendacky , Baoquan He , Vivek Goyal , Dave Young , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-coco@lists.linux.dev, linux-efi@vger.kernel.org, kexec@lists.infradead.org Subject: [PATCH 2/3] proc/kcore: Do not map unaccepted memory Date: Wed, 6 Sep 2023 10:39:01 +0300 Message-Id: <20230906073902.4229-3-adrian.hunter@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230906073902.4229-1-adrian.hunter@intel.com> References: <20230906073902.4229-1-adrian.hunter@intel.com> MIME-Version: 1.0 Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org Support for unaccepted memory was added recently, refer commit dcdfdd40fa82 ("mm: Add support for unaccepted memory"), whereby a virtual machine may need to accept memory before it can be used. Do not map unaccepted memory because it can cause the guest to fail. For /proc/kcore, which is read-only and does not support mmap, this means a read of unaccepted memory will return zeros. Fixes: dcdfdd40fa82 ("mm: Add support for unaccepted memory") Signed-off-by: Adrian Hunter --- fs/proc/kcore.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c index 23fc24d16b31..a3091c5ed871 100644 --- a/fs/proc/kcore.c +++ b/fs/proc/kcore.c @@ -76,6 +76,13 @@ static int pfn_is_ram(unsigned long pfn) return 1; } +static bool pfn_is_unaccepted_memory(unsigned long pfn) +{ + phys_addr_t paddr = pfn << PAGE_SHIFT; + + return range_contains_unaccepted_memory(paddr, paddr + PAGE_SIZE); +} + /* This doesn't grab kclist_lock, so it should only be used at init time. */ void __init kclist_add(struct kcore_list *new, void *addr, size_t size, int type) @@ -546,7 +553,8 @@ static ssize_t read_kcore_iter(struct kiocb *iocb, struct iov_iter *iter) * and explicitly excluded physical ranges. */ if (!page || PageOffline(page) || - is_page_hwpoison(page) || !pfn_is_ram(pfn)) { + is_page_hwpoison(page) || !pfn_is_ram(pfn) || + pfn_is_unaccepted_memory(pfn)) { if (iov_iter_zero(tsz, iter) != tsz) { ret = -EFAULT; goto out;