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=-16.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 04EEFC07E95 for ; Wed, 14 Jul 2021 01:02:23 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 517AF6136E for ; Wed, 14 Jul 2021 01:02:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 517AF6136E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 79AD76B0088; Tue, 13 Jul 2021 21:02:22 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 74B226B008C; Tue, 13 Jul 2021 21:02:22 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 612696B0092; Tue, 13 Jul 2021 21:02:22 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0104.hostedemail.com [216.40.44.104]) by kanga.kvack.org (Postfix) with ESMTP id 3AF876B0088 for ; Tue, 13 Jul 2021 21:02:22 -0400 (EDT) Received: from smtpin05.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 34FD32CFE5 for ; Wed, 14 Jul 2021 01:02:21 +0000 (UTC) X-FDA: 78359392482.05.76A65C0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf03.hostedemail.com (Postfix) with ESMTP id CA6A030000BF for ; Wed, 14 Jul 2021 01:02:20 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id C812A61374; Wed, 14 Jul 2021 01:02:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1626224539; bh=0GCbAO7JlNLkfPCYJxBiQU6zDaEcVTd1xqmP5VK8BAA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=bBmYlzYtX75vr34HiQ0KJQ4ZXbviYmm4fPVjobehJSy2GX2jYpZeQ2sALld15GjkB YGzklpfcgA3soB8OV8Z/kZFHJcLphaSORdqkBZDnjkaetzqYnp5Hrna7g8ol9c7RE9 wH1B1Xp9MjO4demnP/4yu5Iq2WA8fyrn1Z/h8zyQ= Date: Tue, 13 Jul 2021 18:02:19 -0700 From: Andrew Morton To: Mike Kravetz Cc: Joao Martins , linux-mm@kvack.org Subject: Re: [PATCH v1] mm/hugetlb: fix refs calculation from unaligned @vaddr Message-Id: <20210713180219.26b834e4a21d817eee5c0863@linux-foundation.org> In-Reply-To: <1d7eac17-8758-63bb-a0ac-968723af6e2d@oracle.com> References: <20210713152440.28650-1-joao.m.martins@oracle.com> <1d7eac17-8758-63bb-a0ac-968723af6e2d@oracle.com> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=bBmYlzYt; spf=pass (imf03.hostedemail.com: domain of akpm@linux-foundation.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none X-Rspamd-Server: rspam02 X-Stat-Signature: uzncw399z6tnpw648ngmtxkfasqtisot X-Rspamd-Queue-Id: CA6A030000BF X-HE-Tag: 1626224540-766414 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 Tue, 13 Jul 2021 13:29:20 -0700 Mike Kravetz wrote: > On 7/13/21 8:24 AM, Joao Martins wrote: > > > The syzbot repro no longer reproduces after this patch. Additionally, ran > > the libhugetlbfs tests (which were passing without this), gup_test and an > > extra gup_test extension that take an offset to exercise gup() starting > > address not being page aligned. > > --- > > mm/hugetlb.c | 5 +++-- > > 1 file changed, 3 insertions(+), 2 deletions(-) > > > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > > index 924553aa8f78..dfc940d5221d 100644 > > --- a/mm/hugetlb.c > > +++ b/mm/hugetlb.c > > @@ -5440,8 +5440,9 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, > > continue; > > } > > > > - refs = min3(pages_per_huge_page(h) - pfn_offset, > > - (vma->vm_end - vaddr) >> PAGE_SHIFT, remainder); > > + /* vaddr may not be aligned to PAGE_SIZE */ > > + refs = min3(pages_per_huge_page(h) - pfn_offset, remainder, > > + (vma->vm_end - ALIGN_DOWN(vaddr, PAGE_SIZE)) >> PAGE_SHIFT); > > > > if (pages || vmas) > > record_subpages_vmas(mem_map_offset(page, pfn_offset), > > > > Reviewed-by: Mike Kravetz I'll add cc:stable to this.