From patchwork Fri Jul 9 13:18:44 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 472293 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=-19.0 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, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT 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 62A2FC07E9C for ; Fri, 9 Jul 2021 13:19:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4C09B613BC for ; Fri, 9 Jul 2021 13:19:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232319AbhGINW3 (ORCPT ); Fri, 9 Jul 2021 09:22:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:53002 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232287AbhGINWW (ORCPT ); Fri, 9 Jul 2021 09:22:22 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 67C4F613BC; Fri, 9 Jul 2021 13:19:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1625836774; bh=13fLalwGyjAXfWQRKG4fhgYKFlwATWbaXJDl28AEiBg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0KBsqyGczc6avhagmiOIC9L+LENpnDjB8GqE34x3nOsvCpY2bqrarwmIxXuA7Kwo9 hphzRbi1X5+5ipU5lNtHua4tKQB5Y0wSRP4ZeL8rKYpMDUdIHD1ik0Yj4x1RyIWbRg 7EIQAUhD1llXTd6iJwLlu9KAmcDOXvHOpdEhy9gs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Hugh Dickins , "Kirill A. Shutemov" , Alistair Popple , Matthew Wilcox , Peter Xu , Ralph Campbell , Wang Yugui , Will Deacon , Yang Shi , Zi Yan , Andrew Morton , Linus Torvalds , Sasha Levin Subject: [PATCH 4.14 13/25] mm: page_vma_mapped_walk(): crossing page table boundary Date: Fri, 9 Jul 2021 15:18:44 +0200 Message-Id: <20210709131635.677301580@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210709131627.928131764@linuxfoundation.org> References: <20210709131627.928131764@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Hugh Dickins [ Upstream commit 448282487483d6fa5b2eeeafaa0acc681e544a9c ] page_vma_mapped_walk() cleanup: adjust the test for crossing page table boundary - I believe pvmw->address is always page-aligned, but nothing else here assumed that; and remember to reset pvmw->pte to NULL after unmapping the page table, though I never saw any bug from that. Link: https://lkml.kernel.org/r/799b3f9c-2a9e-dfef-5d89-26e9f76fd97@google.com Signed-off-by: Hugh Dickins Acked-by: Kirill A. Shutemov Cc: Alistair Popple Cc: Matthew Wilcox Cc: Peter Xu Cc: Ralph Campbell Cc: Wang Yugui Cc: Will Deacon Cc: Yang Shi Cc: Zi Yan Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- mm/page_vma_mapped.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c index 92d7f574b8ab..2463ba78959b 100644 --- a/mm/page_vma_mapped.c +++ b/mm/page_vma_mapped.c @@ -239,16 +239,16 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw) if (pvmw->address >= end) return not_found(pvmw); /* Did we cross page table boundary? */ - if (pvmw->address % PMD_SIZE == 0) { - pte_unmap(pvmw->pte); + if ((pvmw->address & (PMD_SIZE - PAGE_SIZE)) == 0) { if (pvmw->ptl) { spin_unlock(pvmw->ptl); pvmw->ptl = NULL; } + pte_unmap(pvmw->pte); + pvmw->pte = NULL; goto restart; - } else { - pvmw->pte++; } + pvmw->pte++; } while (pte_none(*pvmw->pte)); if (!pvmw->ptl) {