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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 A0CFCC49EA3 for ; Mon, 28 Jun 2021 14:33:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8D7C660C3E for ; Mon, 28 Jun 2021 14:33:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234443AbhF1Ofz (ORCPT ); Mon, 28 Jun 2021 10:35:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:35964 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234483AbhF1Ocr (ORCPT ); Mon, 28 Jun 2021 10:32:47 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 439A161CDD; Mon, 28 Jun 2021 14:27:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1624890464; bh=s8lNDiuZotoSOodDqr/zgI3yS8B0ljGuHDkI3eMccW8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=b5Jv5a0mqCfXsQg+ge5oKYCebeDmrq+F4buwaNMMtFfyjRSWGbEXR30y56X+UhtLa kttYP3CvkaRN0dN0iR/2y4yKQ3OuGadDaTJnv21aUR6YtIihjNTvP7LwaGd8kq4jXW PqDgAgzJQM0Mw0iTHHAjFqbkm8JONTyBvWP/R6mUWUQYnzaWgmJwTOfnN/pVKNR5tr 3iIbJ8aPTEpl9ACtVU/fCwbRSyRq9GFwhExHEdwE+nl5ctLsOiATnCCZIj1Ik6noX9 96PiY9GfP2bWwhm/T60hO/zhxxccW640M4vKTcpNKNWuKg7lmmyYvt7ik486ggCEIn 5OybY8ZcQP9ng== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Hugh Dickins , "Kirill A . Shutemov" , Wang Yugui , Alistair Popple , Matthew Wilcox , Peter Xu , Ralph Campbell , Will Deacon , Yang Shi , Zi Yan , Andrew Morton , Linus Torvalds , Greg Kroah-Hartman Subject: [PATCH 5.10 091/101] mm/thp: another PVMW_SYNC fix in page_vma_mapped_walk() Date: Mon, 28 Jun 2021 10:25:57 -0400 Message-Id: <20210628142607.32218-92-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210628142607.32218-1-sashal@kernel.org> References: <20210628142607.32218-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v5.x/stable-review/patch-5.10.47-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-5.10.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 5.10.47-rc1 X-KernelTest-Deadline: 2021-06-30T14:25+00:00 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Hugh Dickins commit a7a69d8ba88d8dcee7ef00e91d413a4bd003a814 upstream. Aha! Shouldn't that quick scan over pte_none()s make sure that it holds ptlock in the PVMW_SYNC case? That too might have been responsible for BUGs or WARNs in split_huge_page_to_list() or its unmap_page(), though I've never seen any. Link: https://lkml.kernel.org/r/1bdf384c-8137-a149-2a1e-475a4791c3c@google.com Link: https://lore.kernel.org/linux-mm/20210412180659.B9E3.409509F4@e16-tech.com/ Fixes: ace71a19cec5 ("mm: introduce page_vma_mapped_walk()") Signed-off-by: Hugh Dickins Acked-by: Kirill A. Shutemov Tested-by: Wang Yugui Cc: Alistair Popple Cc: Matthew Wilcox Cc: Peter Xu Cc: Ralph Campbell Cc: Will Deacon Cc: Yang Shi Cc: Zi Yan Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/page_vma_mapped.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c index 2ad76a3d871d..610ebbee787c 100644 --- a/mm/page_vma_mapped.c +++ b/mm/page_vma_mapped.c @@ -275,6 +275,10 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw) goto restart; } pvmw->pte++; + if ((pvmw->flags & PVMW_SYNC) && !pvmw->ptl) { + pvmw->ptl = pte_lockptr(mm, pvmw->pmd); + spin_lock(pvmw->ptl); + } } while (pte_none(*pvmw->pte)); if (!pvmw->ptl) { -- 2.30.2