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=-10.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 EF4CEC388F7 for ; Fri, 13 Nov 2020 07:03:30 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A2535221EB for ; Fri, 13 Nov 2020 07:03:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="UcPHMzKc" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A2535221EB Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=+cCUO8kFVJNmlRPXIhPpnW6eq65tGjKiZiBxr1D1GOc=; b=UcPHMzKcXjxHBJYylf7YLqZmN CoW4dT5AsQbu3q8OckxJ57SEl8LtW8UtU+z7HsUBbGn3jewlGLiBpOEgwuc0ccyQObl1YpSkcavxC ZqJYkvUkLIosQEZ9/jAhI7B3mwoU8XnkzaOz5BjPXGw1J775spFfet5HjnqnBJiA8ljSRnVLtjvcB DBfeL/fCkK+HhVK0r0vruu0kwA91NeuyqiUibERFF9yLJiKMmCrN0SNq7CNyypct4NNcqgZSYAmVT /tmyGgKDRXRG0Dxabz7CubpAgea+oESJkbQkoozWKEMIqSZ0Pixb9txV8SlJ+Mx3F1LR+y6ra1DZw xjgmVmy2Q==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kdT6w-0002G3-By; Fri, 13 Nov 2020 07:03:06 +0000 Received: from foss.arm.com ([217.140.110.172]) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kdT6s-0002DO-2l for linux-arm-kernel@lists.infradead.org; Fri, 13 Nov 2020 07:03:03 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3AE15142F; Thu, 12 Nov 2020 23:02:58 -0800 (PST) Received: from [10.163.80.57] (unknown [10.163.80.57]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 511303F718; Thu, 12 Nov 2020 23:02:50 -0800 (PST) Subject: Re: [PATCH] arm64: mm: account for hotplug memory when randomizing the linear region To: Ard Biesheuvel References: <20201014081857.3288-1-ardb@kernel.org> <160503561804.1015659.16599672230432576934.b4-ty@arm.com> <20201112092558.GC29613@gaia> <2f0d9bc5-6288-7388-ff10-97198dabac6f@arm.com> From: Anshuman Khandual Message-ID: Date: Fri, 13 Nov 2020 12:32:47 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201113_020302_264750_EC1EBB8E X-CRM114-Status: GOOD ( 27.14 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , gshan@redhat.com, Steve Capper , Catalin Marinas , David Hildenbrand , Linux Kernel Mailing List , Steven Price , Mark Brown , Marc Zyngier , Will Deacon , Linux ARM , Robin Murphy Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 11/13/20 11:44 AM, Ard Biesheuvel wrote: > On Fri, 13 Nov 2020 at 04:16, Anshuman Khandual > wrote: >> >> >> >> On 11/12/20 2:55 PM, Catalin Marinas wrote: >>> Hi Anshuman, >>> >>> On Wed, Nov 11, 2020 at 09:18:56AM +0530, Anshuman Khandual wrote: >>>> On 11/11/20 12:44 AM, Catalin Marinas wrote: >>>>> On Wed, 14 Oct 2020 10:18:57 +0200, Ard Biesheuvel wrote: >>>>>> As a hardening measure, we currently randomize the placement of >>>>>> physical memory inside the linear region when KASLR is in effect. >>>>>> Since the random offset at which to place the available physical >>>>>> memory inside the linear region is chosen early at boot, it is >>>>>> based on the memblock description of memory, which does not cover >>>>>> hotplug memory. The consequence of this is that the randomization >>>>>> offset may be chosen such that any hotplugged memory located above >>>>>> memblock_end_of_DRAM() that appears later is pushed off the end of >>>>>> the linear region, where it cannot be accessed. >>>>>> >>>>>> [...] >>>>> >>>>> Applied to arm64 (for-next/mem-hotplug), thanks! >>>>> >>>>> [1/1] arm64: mm: account for hotplug memory when randomizing the linear region >>>>> https://git.kernel.org/arm64/c/97d6786e0669 >>>> >>>> Got delayed and never made here in time, sorry about that. Nonetheless, >>>> I have got something working with respect to the generic mechanism that >>>> David Hildenbrand had asked for earlier. >>>> >>>> https://patchwork.kernel.org/project/linux-arm-kernel/patch/1600332402-30123-1-git-send-email-anshuman.khandual@arm.com/ >>> >>> There was a lot of discussion around this patch but I haven't seen any >>> new version posted. >> >> Just posted before some time. >> >> https://lore.kernel.org/linux-arm-kernel/1605236574-14636-1-git-send-email-anshuman.khandual@arm.com/ >> > > You failed to cc me on that patch. I could see 'ardb@kernel.org' marked as a copy on the patch. You did not receive the email ? The CC list is in the commit message itself. Even the lore.kernel.org based URL does list you email as well. Not sure what might have happened. Cc: Catalin Marinas Cc: Will Deacon Cc: Mark Rutland Cc: Ard Biesheuvel Cc: Steven Price Cc: Robin Murphy Cc: David Hildenbrand Cc: Andrew Morton Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org > > The logic looks correct but please fix up the comment block: > - PAGE_END is no longer defined in terms of vabits_actual > - bits [51..48] are not ignored by the MMU > > Actually, I think the entire second paragraph of that comment block > can be dropped. And from the commit message as well, had reused it in both places. > > Please also fix up the coding style: > - put && at the end of the first line > - drop the redundant parens > - fix the indentation Does this look okay ? static bool inside_linear_region(u64 start, u64 size) { /* * 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); } _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel