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=-16.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 5F009C433E0 for ; Tue, 2 Mar 2021 10:04:34 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E791C64F0F for ; Tue, 2 Mar 2021 10:04:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E791C64F0F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 7BE308D00F8; Tue, 2 Mar 2021 05:04:33 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 7202A8D0063; Tue, 2 Mar 2021 05:04:33 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5E7EC8D00F8; Tue, 2 Mar 2021 05:04:33 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0021.hostedemail.com [216.40.44.21]) by kanga.kvack.org (Postfix) with ESMTP id 4332F8D0063 for ; Tue, 2 Mar 2021 05:04:33 -0500 (EST) Received: from smtpin30.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 0FADD52C1 for ; Tue, 2 Mar 2021 10:04:33 +0000 (UTC) X-FDA: 77874499626.30.6D975F8 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf20.hostedemail.com (Postfix) with ESMTP id B5DE6F8 for ; Tue, 2 Mar 2021 10:04:31 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 031E164F1B; Tue, 2 Mar 2021 10:04:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1614679471; bh=pACDq5dh9SnWHeToI15lAiv7Zc9+44fWIB6RMHF0BEE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oFZA3+CfC+xOMR2lWPr7on7rEzOVojEsEaxFZgnroqRvY/QhbYpKja31vbfao/GJk WGP8F0Si5Hc7JLt9UEQFGXi18MZvPWJz5us7WBglcI8Ev4eJmo5H3F7WxtNrESNiVx +kJVAWKpUOiXAlmie414eLbuDHDF1tYHtQSeWg2mJRSEObt+tXTd0xj4Gptsstsm5H qklhTAn6uuNmVk6A6sYV7kXF3Su/kjHE9ROUGUgv16/RTVON3ulgull8dX6yH6Vyp2 9g2HqqqVK7LFWIkZDeU/n/coy8Iqagxp3YsBv93SPrBpmMkNzgfYB+XIK7czAhaqFR b2+Gevc5FCo9g== From: Mike Rapoport To: x86@kernel.org Cc: Andrew Morton , Andrea Arcangeli , Baoquan He , Borislav Petkov , David Hildenbrand , "H. Peter Anvin" , Ingo Molnar , Mel Gorman , Michal Hocko , Mike Rapoport , Mike Rapoport , Qian Cai , Thomas Gleixner , Vlastimil Babka , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Borislav Petkov Subject: [PATCH v3 2/2] x86/setup: merge several reservations of start of the memory Date: Tue, 2 Mar 2021 12:04:06 +0200 Message-Id: <20210302100406.22059-3-rppt@kernel.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20210302100406.22059-1-rppt@kernel.org> References: <20210302100406.22059-1-rppt@kernel.org> MIME-Version: 1.0 X-Stat-Signature: kisk4fdhh9ykgpsqrpqaq368uoxk6n6h X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: B5DE6F8 Received-SPF: none (kernel.org>: No applicable sender policy available) receiver=imf20; identity=mailfrom; envelope-from=""; helo=mail.kernel.org; client-ip=198.145.29.99 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1614679471-723124 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Mike Rapoport Currently the first several pages are reserved both to avoid leaking thei= r contents on systems with L1TF and to avoid corrupting BIOS memory. Merge the two memory reservations. Signed-off-by: Mike Rapoport Reviewed-by: David Hildenbrand Acked-by: Borislav Petkov --- arch/x86/kernel/setup.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 3e3c6036b023..776fc9b3fafe 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -713,11 +713,6 @@ static int __init parse_reservelow(char *p) =20 early_param("reservelow", parse_reservelow); =20 -static void __init trim_low_memory_range(void) -{ - memblock_reserve(0, ALIGN(reserve_low, PAGE_SIZE)); -} - static void __init early_reserve_memory(void) { /* @@ -730,10 +725,17 @@ static void __init early_reserve_memory(void) (unsigned long)__end_of_kernel_reserve - (unsigned long)_text); =20 /* - * Make sure page 0 is always reserved because on systems with - * L1TF its contents can be leaked to user processes. + * The first 4Kb of memory is a BIOS owned area, but generally it is + * not listed as such in the E820 table. + * + * Reserve the first memory page and typically some additional + * memory (64KiB by default) since some BIOSes are known to corrupt + * low memory. See the Kconfig help text for X86_RESERVE_LOW. + * + * In addition, make sure page 0 is always reserved because on + * systems with L1TF its contents can be leaked to user processes. */ - memblock_reserve(0, PAGE_SIZE); + memblock_reserve(0, ALIGN(reserve_low, PAGE_SIZE)); =20 early_reserve_initrd(); =20 @@ -746,7 +748,6 @@ static void __init early_reserve_memory(void) reserve_bios_regions(); =20 trim_snb_memory(); - trim_low_memory_range(); } =20 /* --=20 2.28.0