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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0A182C433F5 for ; Tue, 19 Apr 2022 10:22:16 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5203A6B00C5; Tue, 19 Apr 2022 06:22:16 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4CF876B00C6; Tue, 19 Apr 2022 06:22:16 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3717C8D0047; Tue, 19 Apr 2022 06:22:16 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.a.hostedemail.com [64.99.140.24]) by kanga.kvack.org (Postfix) with ESMTP id 2968A6B00C5 for ; Tue, 19 Apr 2022 06:22:16 -0400 (EDT) Received: from smtpin05.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id D819F6229F for ; Tue, 19 Apr 2022 10:22:15 +0000 (UTC) X-FDA: 79373238630.05.C2BD7DB Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf28.hostedemail.com (Postfix) with ESMTP id 38076C0010 for ; Tue, 19 Apr 2022 10:22:14 +0000 (UTC) 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 1555D23A; Tue, 19 Apr 2022 03:22:14 -0700 (PDT) Received: from [10.163.40.223] (unknown [10.163.40.223]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B4DDA3F73B; Tue, 19 Apr 2022 03:22:05 -0700 (PDT) Message-ID: <073cb6a6-3dbc-75d4-dbfe-a5299a6b0510@arm.com> Date: Tue, 19 Apr 2022 15:52:49 +0530 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCH -next v4 3/4] arm64: mm: add support for page table check Content-Language: en-US To: Tong Tiangen , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Pasha Tatashin , Andrew Morton , Catalin Marinas , Will Deacon , Paul Walmsley , Palmer Dabbelt , Albert Ou Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-riscv@lists.infradead.org, Kefeng Wang , Guohanjun References: <20220418034444.520928-1-tongtiangen@huawei.com> <20220418034444.520928-4-tongtiangen@huawei.com> From: Anshuman Khandual In-Reply-To: <20220418034444.520928-4-tongtiangen@huawei.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Stat-Signature: u6qaw7hg3oji19iy5bnf7wsmyyucim8t X-Rspam-User: Authentication-Results: imf28.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf28.hostedemail.com: domain of anshuman.khandual@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=anshuman.khandual@arm.com X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 38076C0010 X-HE-Tag: 1650363734-305887 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 4/18/22 09:14, Tong Tiangen wrote: > +#ifdef CONFIG_PAGE_TABLE_CHECK > +static inline bool pte_user_accessible_page(pte_t pte) > +{ > + return pte_present(pte) && (pte_user(pte) || pte_user_exec(pte)); > +} > + > +static inline bool pmd_user_accessible_page(pmd_t pmd) > +{ > + return pmd_present(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); > +} > + > +static inline bool pud_user_accessible_page(pud_t pud) > +{ > + return pud_present(pud) && pud_user(pud); > +} > +#endif Wondering why check for these page table entry states when init_mm has already being excluded ? Should not user page tables be checked for in entirety for all updates ? what is the rationale for filtering out only pxx_user_access_page entries ?