From patchwork Mon Sep 11 11:21:14 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Adrian Hunter X-Patchwork-Id: 724063 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 774FBCA0ED0 for ; Mon, 11 Sep 2023 21:26:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241318AbjIKVSC (ORCPT ); Mon, 11 Sep 2023 17:18:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55176 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236761AbjIKLVt (ORCPT ); Mon, 11 Sep 2023 07:21:49 -0400 Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D72BECDD; Mon, 11 Sep 2023 04:21:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1694431305; x=1725967305; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=M9e2eeN/kfGtE3gA5n3bGk//DgEyKzp702J0NcFnLyE=; b=NKfOwgfGSd6WrjeU3QDdKYQhFHVc+GWTzubfzrKE2Q/PGHaATxUev7vj qBXZPntQ6En3mGr5uzb1O9J5e1h+uTIrq4JMvThMoE1T0U9vHE/oyTGw0 QT92dbYgGxd/1+Zjrb79ABRUdIyHyPw60S33f5GaZwLRQHnvuh9AdY5Gf aUVNU0o5HlPv/7O1ArrBouGe0TB7sIdH128/9bmaaDWDfNv/SIASu42Yt VVN3J3ecPzsc4QRuitNMa/RyRCtZzM5D0rQyiNAf4ryDXe9TtH5Y+P+NQ UnAbdZOs8nK1gU17Tayk2m0CzanGy3uulgm0hlKcMqiQGT6zJuoovHiql g==; X-IronPort-AV: E=McAfee;i="6600,9927,10829"; a="358358431" X-IronPort-AV: E=Sophos;i="6.02,243,1688454000"; d="scan'208";a="358358431" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Sep 2023 04:21:44 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10829"; a="778356406" X-IronPort-AV: E=Sophos;i="6.02,243,1688454000"; d="scan'208";a="778356406" Received: from ahunter6-mobl1.ger.corp.intel.com (HELO ahunter-VirtualBox.home\044ger.corp.intel.com) ([10.251.216.218]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Sep 2023 04:21:35 -0700 From: Adrian Hunter To: "Kirill A. Shutemov" , Borislav Petkov , Andrew Morton , Ard Biesheuvel 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 V2 2/2] proc/kcore: Do not try to access unaccepted memory Date: Mon, 11 Sep 2023 14:21:14 +0300 Message-Id: <20230911112114.91323-3-adrian.hunter@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230911112114.91323-1-adrian.hunter@intel.com> References: <20230911112114.91323-1-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 try to access 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. Signed-off-by: Adrian Hunter --- fs/proc/kcore.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) Changes in V2: Change patch subject and commit message Do not open code pfn_is_unaccepted_memory() diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c index 23fc24d16b31..6422e569b080 100644 --- a/fs/proc/kcore.c +++ b/fs/proc/kcore.c @@ -546,7 +546,8 @@ 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;