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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, 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 B62E6C433E3 for ; Mon, 29 Mar 2021 09:05:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8A39F619DE for ; Mon, 29 Mar 2021 09:05:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236767AbhC2JDF (ORCPT ); Mon, 29 Mar 2021 05:03:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:32900 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234080AbhC2Iii (ORCPT ); Mon, 29 Mar 2021 04:38:38 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2F50C61581; Mon, 29 Mar 2021 08:38:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1617007117; bh=+Dguk+tlJHUA0wg2xs5ieUr1BlRyk8E9wgOK0mSAPqo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BwaudfTWJJgqqDlxPg8fXQRuQEH0e6KiPE4OKwf2ATsIhKHVRoAD0aMW73401EcVW xPpfNiY3M3td0mm27dtj8zl2iknVrgIeqIo2DFGr+58NQs2+0exffenGdFd4lmMPCc QgDHJdwHF1KlA5o67WAr/uCu+MATfYbFQ8CWLyqs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pavel Tatashin , Tyler Hicks , Anshuman Khandual , Will Deacon , Sasha Levin Subject: [PATCH 5.11 226/254] arm64: mm: correct the inside linear map range during hotplug check Date: Mon, 29 Mar 2021 09:59:02 +0200 Message-Id: <20210329075640.512816658@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210329075633.135869143@linuxfoundation.org> References: <20210329075633.135869143@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Pavel Tatashin [ Upstream commit ee7febce051945be28ad86d16a15886f878204de ] Memory hotplug may fail on systems with CONFIG_RANDOMIZE_BASE because the linear map range is not checked correctly. The start physical address that linear map covers can be actually at the end of the range because of randomization. Check that and if so reduce it to 0. This can be verified on QEMU with setting kaslr-seed to ~0ul: memstart_offset_seed = 0xffff START: __pa(_PAGE_OFFSET(vabits_actual)) = ffff9000c0000000 END: __pa(PAGE_END - 1) = 1000bfffffff Signed-off-by: Pavel Tatashin Fixes: 58284a901b42 ("arm64/mm: Validate hotplug range before creating linear mapping") Tested-by: Tyler Hicks Reviewed-by: Anshuman Khandual Link: https://lore.kernel.org/r/20210216150351.129018-2-pasha.tatashin@soleen.com Signed-off-by: Will Deacon Signed-off-by: Sasha Levin --- arch/arm64/mm/mmu.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 92b3be127796..3ca02e917598 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -1446,6 +1446,22 @@ static void __remove_pgd_mapping(pgd_t *pgdir, unsigned long start, u64 size) struct range arch_get_mappable_range(void) { struct range mhp_range; + u64 start_linear_pa = __pa(_PAGE_OFFSET(vabits_actual)); + u64 end_linear_pa = __pa(PAGE_END - 1); + + if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { + /* + * Check for a wrap, it is possible because of randomized linear + * mapping the start physical address is actually bigger than + * the end physical address. In this case set start to zero + * because [0, end_linear_pa] range must still be able to cover + * all addressable physical addresses. + */ + if (start_linear_pa > end_linear_pa) + start_linear_pa = 0; + } + + WARN_ON(start_linear_pa > end_linear_pa); /* * Linear mapping region is the range [PAGE_OFFSET..(PAGE_END - 1)] @@ -1453,8 +1469,9 @@ struct range arch_get_mappable_range(void) * range which can be mapped inside this linear mapping range, must * also be derived from its end points. */ - mhp_range.start = __pa(_PAGE_OFFSET(vabits_actual)); - mhp_range.end = __pa(PAGE_END - 1); + mhp_range.start = start_linear_pa; + mhp_range.end = end_linear_pa; + return mhp_range; } -- 2.30.1