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=-18.8 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, URIBL_BLOCKED,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 E510CC43460 for ; Mon, 5 Apr 2021 09:08:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BD9FF61398 for ; Mon, 5 Apr 2021 09:08:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238591AbhDEJIW (ORCPT ); Mon, 5 Apr 2021 05:08:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:50584 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238140AbhDEJGJ (ORCPT ); Mon, 5 Apr 2021 05:06:09 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3C8A661398; Mon, 5 Apr 2021 09:06:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1617613562; bh=BcWyBECpPqwZcqOGPUhAaZ7I1FB3LVm5bU5MrcdkYVs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=I+IfUaH00nef3m3JYNfZmBIYq0ZcHo3XVhd/rEmo4Tj5dkaOw21H3KK/6bOWTVj9I EFlggnB7hxMJp+IqrAlvQ1KpVK2xycmhj7SenO2gcsp7+yUAzRHsgmOJaUDVCzH2s4 +FEPJby7FY9ctx1L3IzV7sRBjlqP5y7WnrhCiHc4= 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 5.10 001/126] arm64: mm: correct the inside linear map range during hotplug check Date: Mon, 5 Apr 2021 10:52:43 +0200 Message-Id: <20210405085031.094413366@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210405085031.040238881@linuxfoundation.org> References: <20210405085031.040238881@linuxfoundation.org> User-Agent: quilt/0.66 X-stable: review X-Patchwork-Hint: ignore 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 | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 6aabf1eced31..afdad7607850 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -1447,14 +1447,30 @@ static void __remove_pgd_mapping(pgd_t *pgdir, unsigned long start, u64 size) static bool inside_linear_region(u64 start, u64 size) { + 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)] * accommodating both its ends but excluding PAGE_END. Max physical * range which can be mapped inside this linear mapping range, must * also be derived from its end points. */ - return start >= __pa(_PAGE_OFFSET(vabits_actual)) && - (start + size - 1) <= __pa(PAGE_END - 1); + return start >= start_linear_pa && (start + size - 1) <= end_linear_pa; } int arch_add_memory(int nid, u64 start, u64 size, -- 2.30.1