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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BDE3DC4332F for ; Tue, 29 Nov 2022 19:39:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236926AbiK2Ti7 (ORCPT ); Tue, 29 Nov 2022 14:38:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48670 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236996AbiK2Th3 (ORCPT ); Tue, 29 Nov 2022 14:37:29 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 952C15917E for ; Tue, 29 Nov 2022 11:35:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1669750544; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=tlgp91ck5zE/ROfq0OY9j8l1q/C3T3fwuEiiEDoRd8M=; b=PLmp9qAAVoXZ/DLCrhHauwbfIJ8eucPnqbLK/nRBJIKfSy2xRYyOfG9cpnvH4yNsOCxf60 ONlKONJCwUJht1zh2iZ82SSNfzcMDGnyIEYpeBPBqEMkp7MCCQCSIvZDQqthMmEHJpg43b 9OyN7osSfnd1FAHdBbWORvnupPB2HUQ= Received: from mail-qk1-f197.google.com (mail-qk1-f197.google.com [209.85.222.197]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-413-6Mz9jCuLNK6tvdNUgjXp2w-1; Tue, 29 Nov 2022 14:35:43 -0500 X-MC-Unique: 6Mz9jCuLNK6tvdNUgjXp2w-1 Received: by mail-qk1-f197.google.com with SMTP id u5-20020a05620a0c4500b006fb30780443so32368012qki.22 for ; Tue, 29 Nov 2022 11:35:43 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=tlgp91ck5zE/ROfq0OY9j8l1q/C3T3fwuEiiEDoRd8M=; b=lWfkIv9xg8ZejBv4f/6TxbEFtPTmtTJQhuFtb0mA6ngyiFi9eOLCwYX7bKa849ZW5r vw0KTQFp9XXfCAJhd8JZ4ECUv+Cs3PFq050gxKhdS4PWKB9cy+i0FMf+XIkyVUNTwvPX yTA8MlD/RWK1tBUw+vOJ41Y0VCXuu7Vs5Rn+eDmvxlBF3s3VOgtK4GDI3wbnWfLXME/M kakemfAKk3N/R3sUuQDPM7G/HCwCgNtIzg2j70OAvzhRYP03smopomcvKTm335plKh1K lqYTT5LLwtzZd38ceCAv5SVshAUjD9F5duU/dySEIbdLU5e5n17Q4b90t2D7HUdcnF02 +13w== X-Gm-Message-State: ANoB5pll1dXkrF4iD7lPIt4RtIeXwNBlYmGoJwfBKj1GNgSi6QkrP1Hq 6RnwMuBfiF5xrJ+xY8OXjlx7q+OF292wZ2rJqlxlFVhK22ZarBKgfIZ7/9qo8giEJeozByz/Wgg NPyTwmRvaGoNFsJUFm4QhNXXZ X-Received: by 2002:a05:6214:3607:b0:4c6:fb3e:4993 with SMTP id nv7-20020a056214360700b004c6fb3e4993mr12852435qvb.110.1669750542529; Tue, 29 Nov 2022 11:35:42 -0800 (PST) X-Google-Smtp-Source: AA0mqf4xmfsUZVgeiYSekMVU4CvYl69LMLxbBsqa8kFerZrz4PcOvOhvTZpsuJGzn4pvxETRAceDKA== X-Received: by 2002:a05:6214:3607:b0:4c6:fb3e:4993 with SMTP id nv7-20020a056214360700b004c6fb3e4993mr12852419qvb.110.1669750542285; Tue, 29 Nov 2022 11:35:42 -0800 (PST) Received: from x1n.redhat.com (bras-base-aurron9127w-grc-46-70-31-27-79.dsl.bell.ca. [70.31.27.79]) by smtp.gmail.com with ESMTPSA id n1-20020a05620a294100b006fa16fe93bbsm11313013qkp.15.2022.11.29.11.35.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 29 Nov 2022 11:35:41 -0800 (PST) From: Peter Xu To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: James Houghton , Jann Horn , peterx@redhat.com, Andrew Morton , Andrea Arcangeli , Rik van Riel , Nadav Amit , Miaohe Lin , Muchun Song , Mike Kravetz , David Hildenbrand Subject: [PATCH 08/10] mm/hugetlb: Make walk_hugetlb_range() safe to pmd unshare Date: Tue, 29 Nov 2022 14:35:24 -0500 Message-Id: <20221129193526.3588187-9-peterx@redhat.com> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20221129193526.3588187-1-peterx@redhat.com> References: <20221129193526.3588187-1-peterx@redhat.com> MIME-Version: 1.0 Content-type: text/plain Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Since walk_hugetlb_range() walks the pgtable, it needs the vma lock to make sure the pgtable page will not be freed concurrently. Signed-off-by: Peter Xu --- mm/pagewalk.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/pagewalk.c b/mm/pagewalk.c index 7f1c9b274906..d98564a7be57 100644 --- a/mm/pagewalk.c +++ b/mm/pagewalk.c @@ -302,6 +302,7 @@ static int walk_hugetlb_range(unsigned long addr, unsigned long end, const struct mm_walk_ops *ops = walk->ops; int err = 0; + hugetlb_vma_lock_read(vma); do { next = hugetlb_entry_end(h, addr, end); pte = huge_pte_offset(walk->mm, addr & hmask, sz); @@ -314,6 +315,7 @@ static int walk_hugetlb_range(unsigned long addr, unsigned long end, if (err) break; } while (addr = next, addr != end); + hugetlb_vma_unlock_read(vma); return err; } -- 2.37.3