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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 D374BC433DB for ; Wed, 27 Jan 2021 01:35:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8A316206A1 for ; Wed, 27 Jan 2021 01:35:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404826AbhA0B3x (ORCPT ); Tue, 26 Jan 2021 20:29:53 -0500 Received: from foss.arm.com ([217.140.110.172]:52150 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727140AbhAZSej (ORCPT ); Tue, 26 Jan 2021 13:34:39 -0500 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 A2E0D106F; Tue, 26 Jan 2021 10:33:47 -0800 (PST) Received: from [10.37.12.25] (unknown [10.37.12.25]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id F2E5A3F66B; Tue, 26 Jan 2021 10:33:45 -0800 (PST) Subject: Re: [PATCH] arm64: Fix kernel address detection of __is_lm_address() To: Catalin Marinas Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, stable@vger.kernel.org, Will Deacon , Mark Rutland References: <20210126134056.45747-1-vincenzo.frascino@arm.com> <20210126163638.GA3509@gaia> From: Vincenzo Frascino Message-ID: <1fe8bff7-3ed2-ae96-e52b-dad59cd22539@arm.com> Date: Tue, 26 Jan 2021 18:37:39 +0000 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: <20210126163638.GA3509@gaia> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/26/21 4:36 PM, Catalin Marinas wrote: > On Tue, Jan 26, 2021 at 01:40:56PM +0000, Vincenzo Frascino wrote: >> Currently, the __is_lm_address() check just masks out the top 12 bits >> of the address, but if they are 0, it still yields a true result. >> This has as a side effect that virt_addr_valid() returns true even for >> invalid virtual addresses (e.g. 0x0). >> >> Fix the detection checking that it's actually a kernel address starting >> at PAGE_OFFSET. >> >> Fixes: f4693c2716b35 ("arm64: mm: extend linear region for 52-bit VA configurations") >> Cc: # 5.4.x > > Not sure what happened with the Fixes tag but that's definitely not what > it fixes. The above is a 5.11 commit that preserves the semantics of an > older commit. So it should be: > > Fixes: 68dd8ef32162 ("arm64: memory: Fix virt_addr_valid() using __is_lm_address()") > Yes that is correct. I moved the release to which applies backword but I forgot to update the fixes tag I suppose. ... > > Anyway, no need to repost, I can update the fixes tag myself. > Thank you for this. > In terms of stable backports, it may be cleaner to backport 7bc1a0f9e176 > ("arm64: mm: use single quantity to represent the PA to VA translation") > which has a Fixes tag already but never made it to -stable. On top of > this, we can backport Ard's latest f4693c2716b35 ("arm64: mm: extend > linear region for 52-bit VA configurations"). I just tried these locally > and the conflicts were fairly trivial. > Ok, thank you for digging it. I will give it a try tomorrow. -- Regards, Vincenzo