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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 07C70C433DB for ; Tue, 26 Jan 2021 17:21:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B7DF82083E for ; Tue, 26 Jan 2021 17:21:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391110AbhAZRVq (ORCPT ); Tue, 26 Jan 2021 12:21:46 -0500 Received: from szxga04-in.huawei.com ([45.249.212.190]:11159 "EHLO szxga04-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729807AbhAZGua (ORCPT ); Tue, 26 Jan 2021 01:50:30 -0500 Received: from DGGEMS410-HUB.china.huawei.com (unknown [172.30.72.59]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4DPy4K0Svxz15yXj; Tue, 26 Jan 2021 14:48:33 +0800 (CST) Received: from [10.174.179.117] (10.174.179.117) by DGGEMS410-HUB.china.huawei.com (10.3.19.210) with Microsoft SMTP Server id 14.3.498.0; Tue, 26 Jan 2021 14:49:34 +0800 Subject: Re: [PATCH v11 02/13] mm: apply_to_pte_range warn and fail if a large pte is encountered To: Nicholas Piggin CC: , , , Jonathan Cameron , Christoph Hellwig , Christophe Leroy , Rick Edgecombe , Ding Tianhong , Christoph Hellwig , Linux-MM , Andrew Morton References: <20210126044510.2491820-1-npiggin@gmail.com> <20210126044510.2491820-3-npiggin@gmail.com> From: Miaohe Lin Message-ID: <4cb12137-2944-7973-b0f0-070f6f48bead@huawei.com> Date: Tue, 26 Jan 2021 14:49:34 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <20210126044510.2491820-3-npiggin@gmail.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.179.117] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi: On 2021/1/26 12:44, Nicholas Piggin wrote: > apply_to_pte_range might mistake a large pte for bad, or treat it as a > page table, resulting in a crash or corruption. Add a test to warn and > return error if large entries are found. > > Reviewed-by: Christoph Hellwig > Signed-off-by: Nicholas Piggin > --- > mm/memory.c | 66 +++++++++++++++++++++++++++++++++++++++-------------- > 1 file changed, 49 insertions(+), 17 deletions(-) > > diff --git a/mm/memory.c b/mm/memory.c > index feff48e1465a..672e39a72788 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -2440,13 +2440,21 @@ static int apply_to_pmd_range(struct mm_struct *mm, pud_t *pud, > } > do { > next = pmd_addr_end(addr, end); > - if (create || !pmd_none_or_clear_bad(pmd)) { > - err = apply_to_pte_range(mm, pmd, addr, next, fn, data, > - create, mask); > - if (err) > - break; > + if (pmd_none(*pmd) && !create) > + continue; > + if (WARN_ON_ONCE(pmd_leaf(*pmd))) > + return -EINVAL; > + if (!pmd_none(*pmd) && WARN_ON_ONCE(pmd_bad(*pmd))) { > + if (!create) > + continue; > + pmd_clear_bad(pmd); > } > + err = apply_to_pte_range(mm, pmd, addr, next, > + fn, data, create, mask); > + if (err) > + break; > } while (pmd++, addr = next, addr != end); > + > return err; > } > > @@ -2468,13 +2476,21 @@ static int apply_to_pud_range(struct mm_struct *mm, p4d_t *p4d, > } > do { > next = pud_addr_end(addr, end); > - if (create || !pud_none_or_clear_bad(pud)) { > - err = apply_to_pmd_range(mm, pud, addr, next, fn, data, > - create, mask); > - if (err) > - break; > + if (pud_none(*pud) && !create) > + continue; > + if (WARN_ON_ONCE(pud_leaf(*pud))) > + return -EINVAL; > + if (!pud_none(*pud) && WARN_ON_ONCE(pud_bad(*pud))) { > + if (!create) > + continue; > + pud_clear_bad(pud); > } > + err = apply_to_pmd_range(mm, pud, addr, next, > + fn, data, create, mask); > + if (err) > + break; > } while (pud++, addr = next, addr != end); > + > return err; > } > > @@ -2496,13 +2512,21 @@ static int apply_to_p4d_range(struct mm_struct *mm, pgd_t *pgd, > } > do { > next = p4d_addr_end(addr, end); > - if (create || !p4d_none_or_clear_bad(p4d)) { > - err = apply_to_pud_range(mm, p4d, addr, next, fn, data, > - create, mask); > - if (err) > - break; > + if (p4d_none(*p4d) && !create) > + continue; > + if (WARN_ON_ONCE(p4d_leaf(*p4d))) > + return -EINVAL; > + if (!p4d_none(*p4d) && WARN_ON_ONCE(p4d_bad(*p4d))) { > + if (!create) > + continue; > + p4d_clear_bad(p4d); > } > + err = apply_to_pud_range(mm, p4d, addr, next, > + fn, data, create, mask); > + if (err) > + break; > } while (p4d++, addr = next, addr != end); > + > return err; > } > > @@ -2522,9 +2546,17 @@ static int __apply_to_page_range(struct mm_struct *mm, unsigned long addr, > pgd = pgd_offset(mm, addr); > do { > next = pgd_addr_end(addr, end); > - if (!create && pgd_none_or_clear_bad(pgd)) > + if (pgd_none(*pgd) && !create) > continue; > - err = apply_to_p4d_range(mm, pgd, addr, next, fn, data, create, &mask); > + if (WARN_ON_ONCE(pgd_leaf(*pgd))) > + return -EINVAL; > + if (!pgd_none(*pgd) && WARN_ON_ONCE(pgd_bad(*pgd))) { > + if (!create) > + continue; > + pgd_clear_bad(pgd); > + } > + err = apply_to_p4d_range(mm, pgd, addr, next, > + fn, data, create, &mask); > if (err) > break; > } while (pgd++, addr = next, addr != end); > Looks good to me, thanks. Reviewed-by: Miaohe Lin 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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 8B70CC433E0 for ; Tue, 26 Jan 2021 09:57:50 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (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 C0D1A20780 for ; Tue, 26 Jan 2021 09:57:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C0D1A20780 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4DQ2Gd1KjrzDqnK for ; Tue, 26 Jan 2021 20:57:45 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=huawei.com (client-ip=45.249.212.190; helo=szxga04-in.huawei.com; envelope-from=linmiaohe@huawei.com; receiver=) Received: from szxga04-in.huawei.com (szxga04-in.huawei.com [45.249.212.190]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4DPy5t5VnlzDq7d for ; Tue, 26 Jan 2021 17:49:48 +1100 (AEDT) Received: from DGGEMS410-HUB.china.huawei.com (unknown [172.30.72.59]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4DPy4K0Svxz15yXj; Tue, 26 Jan 2021 14:48:33 +0800 (CST) Received: from [10.174.179.117] (10.174.179.117) by DGGEMS410-HUB.china.huawei.com (10.3.19.210) with Microsoft SMTP Server id 14.3.498.0; Tue, 26 Jan 2021 14:49:34 +0800 Subject: Re: [PATCH v11 02/13] mm: apply_to_pte_range warn and fail if a large pte is encountered To: Nicholas Piggin References: <20210126044510.2491820-1-npiggin@gmail.com> <20210126044510.2491820-3-npiggin@gmail.com> From: Miaohe Lin Message-ID: <4cb12137-2944-7973-b0f0-070f6f48bead@huawei.com> Date: Tue, 26 Jan 2021 14:49:34 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <20210126044510.2491820-3-npiggin@gmail.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.179.117] X-CFilter-Loop: Reflected X-Mailman-Approved-At: Tue, 26 Jan 2021 20:53:32 +1100 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arch@vger.kernel.org, Ding Tianhong , linux-kernel@vger.kernel.org, Christoph Hellwig , Linux-MM , Jonathan Cameron , Andrew Morton , Rick Edgecombe , linuxppc-dev@lists.ozlabs.org, Christoph Hellwig Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Hi: On 2021/1/26 12:44, Nicholas Piggin wrote: > apply_to_pte_range might mistake a large pte for bad, or treat it as a > page table, resulting in a crash or corruption. Add a test to warn and > return error if large entries are found. > > Reviewed-by: Christoph Hellwig > Signed-off-by: Nicholas Piggin > --- > mm/memory.c | 66 +++++++++++++++++++++++++++++++++++++++-------------- > 1 file changed, 49 insertions(+), 17 deletions(-) > > diff --git a/mm/memory.c b/mm/memory.c > index feff48e1465a..672e39a72788 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -2440,13 +2440,21 @@ static int apply_to_pmd_range(struct mm_struct *mm, pud_t *pud, > } > do { > next = pmd_addr_end(addr, end); > - if (create || !pmd_none_or_clear_bad(pmd)) { > - err = apply_to_pte_range(mm, pmd, addr, next, fn, data, > - create, mask); > - if (err) > - break; > + if (pmd_none(*pmd) && !create) > + continue; > + if (WARN_ON_ONCE(pmd_leaf(*pmd))) > + return -EINVAL; > + if (!pmd_none(*pmd) && WARN_ON_ONCE(pmd_bad(*pmd))) { > + if (!create) > + continue; > + pmd_clear_bad(pmd); > } > + err = apply_to_pte_range(mm, pmd, addr, next, > + fn, data, create, mask); > + if (err) > + break; > } while (pmd++, addr = next, addr != end); > + > return err; > } > > @@ -2468,13 +2476,21 @@ static int apply_to_pud_range(struct mm_struct *mm, p4d_t *p4d, > } > do { > next = pud_addr_end(addr, end); > - if (create || !pud_none_or_clear_bad(pud)) { > - err = apply_to_pmd_range(mm, pud, addr, next, fn, data, > - create, mask); > - if (err) > - break; > + if (pud_none(*pud) && !create) > + continue; > + if (WARN_ON_ONCE(pud_leaf(*pud))) > + return -EINVAL; > + if (!pud_none(*pud) && WARN_ON_ONCE(pud_bad(*pud))) { > + if (!create) > + continue; > + pud_clear_bad(pud); > } > + err = apply_to_pmd_range(mm, pud, addr, next, > + fn, data, create, mask); > + if (err) > + break; > } while (pud++, addr = next, addr != end); > + > return err; > } > > @@ -2496,13 +2512,21 @@ static int apply_to_p4d_range(struct mm_struct *mm, pgd_t *pgd, > } > do { > next = p4d_addr_end(addr, end); > - if (create || !p4d_none_or_clear_bad(p4d)) { > - err = apply_to_pud_range(mm, p4d, addr, next, fn, data, > - create, mask); > - if (err) > - break; > + if (p4d_none(*p4d) && !create) > + continue; > + if (WARN_ON_ONCE(p4d_leaf(*p4d))) > + return -EINVAL; > + if (!p4d_none(*p4d) && WARN_ON_ONCE(p4d_bad(*p4d))) { > + if (!create) > + continue; > + p4d_clear_bad(p4d); > } > + err = apply_to_pud_range(mm, p4d, addr, next, > + fn, data, create, mask); > + if (err) > + break; > } while (p4d++, addr = next, addr != end); > + > return err; > } > > @@ -2522,9 +2546,17 @@ static int __apply_to_page_range(struct mm_struct *mm, unsigned long addr, > pgd = pgd_offset(mm, addr); > do { > next = pgd_addr_end(addr, end); > - if (!create && pgd_none_or_clear_bad(pgd)) > + if (pgd_none(*pgd) && !create) > continue; > - err = apply_to_p4d_range(mm, pgd, addr, next, fn, data, create, &mask); > + if (WARN_ON_ONCE(pgd_leaf(*pgd))) > + return -EINVAL; > + if (!pgd_none(*pgd) && WARN_ON_ONCE(pgd_bad(*pgd))) { > + if (!create) > + continue; > + pgd_clear_bad(pgd); > + } > + err = apply_to_p4d_range(mm, pgd, addr, next, > + fn, data, create, &mask); > if (err) > break; > } while (pgd++, addr = next, addr != end); > Looks good to me, thanks. Reviewed-by: Miaohe Lin