From patchwork Mon Mar 29 07:58:43 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 411405 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=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 02294C433EA for ; Mon, 29 Mar 2021 08:29:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D3E9461932 for ; Mon, 29 Mar 2021 08:29:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231675AbhC2I3I (ORCPT ); Mon, 29 Mar 2021 04:29:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:40920 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233637AbhC2IZg (ORCPT ); Mon, 29 Mar 2021 04:25:36 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2104E61964; Mon, 29 Mar 2021 08:25:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1617006301; bh=XRTg73zs/e0zLhEgkqO05U36uGTaz5h2cV9VcugN0HY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QMbr7i8nvwoue0MvAsMCuPIYS2NpdMR86qJC7MPM7GieU5ly7s5+CzzAIma9771bW Z1kHktafMJRJsiMDufpWxl/c5JufIeBGWPTlh1F4w9l+F4FbwPVUmnsqouD+jp7jYi 6vrPxI74LnACr3LzBs8vf75zCHQDw0WJ1oT/EUWk= 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 5.10 192/221] arm64: mm: correct the inside linear map range during hotplug check Date: Mon, 29 Mar 2021 09:58:43 +0200 Message-Id: <20210329075635.533435595@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210329075629.172032742@linuxfoundation.org> References: <20210329075629.172032742@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@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 0635803463a5..10938dbe1f11 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -1448,6 +1448,22 @@ 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)] @@ -1455,8 +1471,9 @@ 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; }