From patchwork Wed May 10 04:42:44 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hugh Dickins X-Patchwork-Id: 13236315 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5E9F2C7EE24 for ; Wed, 10 May 2023 04:43:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230264AbjEJEnB (ORCPT ); Wed, 10 May 2023 00:43:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44246 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232299AbjEJEm6 (ORCPT ); Wed, 10 May 2023 00:42:58 -0400 Received: from mail-yw1-x112c.google.com (mail-yw1-x112c.google.com [IPv6:2607:f8b0:4864:20::112c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EF63840EB for ; Tue, 9 May 2023 21:42:55 -0700 (PDT) Received: by mail-yw1-x112c.google.com with SMTP id 00721157ae682-55a79671a4dso104052127b3.2 for ; Tue, 09 May 2023 21:42:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1683693775; x=1686285775; h=mime-version:references:message-id:in-reply-to:subject:cc:to:from :date:from:to:cc:subject:date:message-id:reply-to; bh=1YvWeTkG3kfP7WDkFLxY3Kk7w85fUEyISH4lFagFGGw=; b=ATuPznBP6lohY0dnWFYXaaNOQNunJEFtD7eF3OFa8KJJUXbFYwyofisXF7mtL2ymFH oTBz56agCcLhFx8YonoqBW6ZmAtrhlvPrmdJAcSpRqyP2mLR5Z/WoSQhVEg2s8MVqDuy Ip95cEIMx73t6Gdt8YSQEVRJTa89FntSD+Di4V6VUK9+4KRIMxTr8+RCmD6ANZu4Rjel BJF/aQ9/sAdSWOQreL897UcsYcMJJWTONr2aX5YmKG/bIAxUtAEn1GX4Jh5f4y/r990Z htjctO7o35ZbKLLksPTYN1h3aK5mSo9ZrVIIV1mS/G/Fv32O9W6ivMXImV5mGNDY0z+m 21CQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1683693775; x=1686285775; h=mime-version:references:message-id:in-reply-to:subject:cc:to:from :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=1YvWeTkG3kfP7WDkFLxY3Kk7w85fUEyISH4lFagFGGw=; b=iofsjqjY5pn8fEqcsUwlDf+3Y27hJLnXJAwXoRMF4geYbFw1xMiD3h8s5wp8EBWdvo 1FmxuGb0rU8cFX1HHXfPFPjzerxSBTVBQeJ+U/02ejNfanYJHX52tUHF3o1HFI6uGYhu PNVwILhLVtW2Y1l5gTcqCjuZ5LP4jjlTDidEy5fKh7/EaX1Mv3hyc9g28nhJtv+XD/15 AulVuZwoUeCbcnKzpWYzLdjFh0OHLOp/o+pf+JV7Q9I3W0DPZGn229yYyjDe9shKorwo 0hRHF0qiMNEozRaDGG58lIt4VlOOL9MSMxKuuTry+SOjFoiJ3RMJcBVctyLbY9ViYWVz rZ8w== X-Gm-Message-State: AC+VfDwaw61Ph4rpOP7RfKotNPZlpMwVPq+iRReEPqfCeHs8Im+Ee9xl uDYK/oId6Kn1zXEBYr5YP9cxsA== X-Google-Smtp-Source: ACHHUZ7fYX2z0RAKmyNqdeM/8QuAhHW9rcUGOaUpv5crEQfaAc/gCUyRWpV2+01J2c8XG3m8+G8szg== X-Received: by 2002:a25:ad98:0:b0:b9d:a8fa:fd6d with SMTP id z24-20020a25ad98000000b00b9da8fafd6dmr17660831ybi.12.1683693775053; Tue, 09 May 2023 21:42:55 -0700 (PDT) Received: from ripple.attlocal.net (172-10-233-147.lightspeed.sntcca.sbcglobal.net. [172.10.233.147]) by smtp.gmail.com with ESMTPSA id x4-20020a056902102400b00b9def138173sm3425234ybt.1.2023.05.09.21.42.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 09 May 2023 21:42:54 -0700 (PDT) Date: Tue, 9 May 2023 21:42:44 -0700 (PDT) From: Hugh Dickins X-X-Sender: hugh@ripple.attlocal.net To: Andrew Morton cc: Mike Kravetz , Mike Rapoport , "Kirill A. Shutemov" , Matthew Wilcox , David Hildenbrand , Suren Baghdasaryan , Qi Zheng , Russell King , Catalin Marinas , Will Deacon , Geert Uytterhoeven , Greg Ungerer , Michal Simek , Thomas Bogendoerfer , Helge Deller , John David Anglin , "Aneesh Kumar K.V" , Michael Ellerman , Alexandre Ghiti , Palmer Dabbelt , Heiko Carstens , Christian Borntraeger , Claudio Imbrenda , John Paul Adrian Glaubitz , "David S. Miller" , Chris Zankel , Max Filippov , x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 01/23] arm: allow pte_offset_map[_lock]() to fail In-Reply-To: <77a5d8c-406b-7068-4f17-23b7ac53bc83@google.com> Message-ID: <5011977-d876-6a24-a3fc-c7e6a02877b8@google.com> References: <77a5d8c-406b-7068-4f17-23b7ac53bc83@google.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org In rare transient cases, not yet made possible, pte_offset_map() and pte_offset_map_lock() may not find a page table: handle appropriately. Signed-off-by: Hugh Dickins --- arch/arm/lib/uaccess_with_memcpy.c | 3 +++ arch/arm/mm/fault-armv.c | 5 ++++- arch/arm/mm/fault.c | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) diff --git a/arch/arm/lib/uaccess_with_memcpy.c b/arch/arm/lib/uaccess_with_memcpy.c index e4c2677cc1e9..2f6163f05e93 100644 --- a/arch/arm/lib/uaccess_with_memcpy.c +++ b/arch/arm/lib/uaccess_with_memcpy.c @@ -74,6 +74,9 @@ pin_page_for_write(const void __user *_addr, pte_t **ptep, spinlock_t **ptlp) return 0; pte = pte_offset_map_lock(current->mm, pmd, addr, &ptl); + if (unlikely(!pte)) + return 0; + if (unlikely(!pte_present(*pte) || !pte_young(*pte) || !pte_write(*pte) || !pte_dirty(*pte))) { pte_unmap_unlock(pte, ptl); diff --git a/arch/arm/mm/fault-armv.c b/arch/arm/mm/fault-armv.c index 0e49154454a6..ca5302b0b7ee 100644 --- a/arch/arm/mm/fault-armv.c +++ b/arch/arm/mm/fault-armv.c @@ -117,8 +117,11 @@ static int adjust_pte(struct vm_area_struct *vma, unsigned long address, * must use the nested version. This also means we need to * open-code the spin-locking. */ - ptl = pte_lockptr(vma->vm_mm, pmd); pte = pte_offset_map(pmd, address); + if (!pte) + return 0; + + ptl = pte_lockptr(vma->vm_mm, pmd); do_pte_lock(ptl); ret = do_adjust_pte(vma, address, pfn, pte); diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index 2418f1efabd8..83598649a094 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -85,6 +85,9 @@ void show_pte(const char *lvl, struct mm_struct *mm, unsigned long addr) break; pte = pte_offset_map(pmd, addr); + if (!pte) + break; + pr_cont(", *pte=%08llx", (long long)pte_val(*pte)); #ifndef CONFIG_ARM_LPAE pr_cont(", *ppte=%08llx",