From patchwork Mon Mar 28 08:24:51 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rolf Eike Beer X-Patchwork-Id: 12793294 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6516AC433EF for ; Mon, 28 Mar 2022 08:24:56 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 960888D0002; Mon, 28 Mar 2022 04:24:55 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8EA348D0001; Mon, 28 Mar 2022 04:24:55 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7B0DF8D0002; Mon, 28 Mar 2022 04:24:55 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0215.hostedemail.com [216.40.44.215]) by kanga.kvack.org (Postfix) with ESMTP id 68C888D0001 for ; Mon, 28 Mar 2022 04:24:55 -0400 (EDT) Received: from smtpin18.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 02A908249980 for ; Mon, 28 Mar 2022 08:24:55 +0000 (UTC) X-FDA: 79293109350.18.8F43149 Received: from mx1.emlix.com (mx1.emlix.com [136.243.223.33]) by imf26.hostedemail.com (Postfix) with ESMTP id 40E9B14003C for ; Mon, 28 Mar 2022 08:24:54 +0000 (UTC) Received: from mailer.emlix.com (p5098be52.dip0.t-ipconnect.de [80.152.190.82]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.emlix.com (Postfix) with ESMTPS id B58C35F8EA; Mon, 28 Mar 2022 10:24:52 +0200 (CEST) From: Rolf Eike Beer To: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: mm: use mmap_assert_write_locked() instead of open coding it Date: Mon, 28 Mar 2022 10:24:51 +0200 Message-ID: <5827758.TJ1SttVevJ@mobilepool36.emlix.com> MIME-Version: 1.0 X-Stat-Signature: jpn3hkoju5gt3rxdxj943y6eh5ske7am Authentication-Results: imf26.hostedemail.com; dkim=none; spf=pass (imf26.hostedemail.com: domain of eb@emlix.com designates 136.243.223.33 as permitted sender) smtp.mailfrom=eb@emlix.com; dmarc=none X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 40E9B14003C X-HE-Tag: 1648455894-235586 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: In case the lock is actually not held at this point this also avoids a stale lock reference if built with NDEBUG. Signed-off-by: Rolf Eike Beer Reviewed-by: Christoph Hellwig --- mm/mmap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index 3aa839f81e63..d62598dc2fdd 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -3561,7 +3561,7 @@ int mm_take_all_locks(struct mm_struct *mm) struct vm_area_struct *vma; struct anon_vma_chain *avc; - BUG_ON(mmap_read_trylock(mm)); + mmap_assert_write_locked(mm); mutex_lock(&mm_all_locks_mutex); @@ -3641,7 +3641,7 @@ void mm_drop_all_locks(struct mm_struct *mm) struct vm_area_struct *vma; struct anon_vma_chain *avc; - BUG_ON(mmap_read_trylock(mm)); + mmap_assert_write_locked(mm); BUG_ON(!mutex_is_locked(&mm_all_locks_mutex)); for (vma = mm->mmap; vma; vma = vma->vm_next) {