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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 BE4D6C38A30 for ; Tue, 21 Apr 2020 02:35:47 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 7FD3922209 for ; Tue, 21 Apr 2020 02:35:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="PU2/E+cI" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7FD3922209 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 1B8A88E0008; Mon, 20 Apr 2020 22:35:47 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 191798E0003; Mon, 20 Apr 2020 22:35:47 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 057B48E0008; Mon, 20 Apr 2020 22:35:46 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0049.hostedemail.com [216.40.44.49]) by kanga.kvack.org (Postfix) with ESMTP id DF9298E0003 for ; Mon, 20 Apr 2020 22:35:46 -0400 (EDT) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id A09D0824556B for ; Tue, 21 Apr 2020 02:35:46 +0000 (UTC) X-FDA: 76730296692.22.test13_4f8307934251a X-HE-Tag: test13_4f8307934251a X-Filterd-Recvd-Size: 2809 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf45.hostedemail.com (Postfix) with ESMTP for ; Tue, 21 Apr 2020 02:35:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=TKDjp2jOs2JqxeWg+YIbR4CsvuwDTxuXsoyCbcQwBSU=; b=PU2/E+cIalL/iK8yL7LXJBBAzB Ek37d+gwqTWnTvrOoRdzOfWls0HEWGAkEKaLGKMwH/nRtRM9HT5pK2P2cG6oqebUBAjOoWRftT+mB 4tG92qGwMNms2rAO8ipnXB+iDXxqMu3awrABI2LHrhF2Fn2CLGcXliGV164QR8TuPcVSjo8eHTBUQ jSmvul7HCfrbynCf1Rxz/p3QFTtGLp1oYLtq+oBhaUQlqjhaAdLXCehtGlY0hRljEjP5GUOl6itI0 PlZeTRkm81zpBom672Gd9ZYzOwgd8J44uK2Nj8gxyT/yquDjT99xeB790Eg0qqUW8a7luMAtmFjIZ mAFq7X+Q==; Received: from willy by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jQilC-0002ij-5G; Tue, 21 Apr 2020 02:35:42 +0000 Date: Mon, 20 Apr 2020 19:35:42 -0700 From: Matthew Wilcox To: Michel Lespinasse Cc: Andrew Morton , linux-mm , LKML , Peter Zijlstra , Laurent Dufour , Vlastimil Babka , Liam Howlett , Jerome Glisse , Davidlohr Bueso , David Rientjes , Hugh Dickins , Ying Han , Jason Gunthorpe , Daniel Jordan Subject: Re: [PATCH v4 09/10] mmap locking API: use lockdep_assert_held Message-ID: <20200421023542.GJ5820@bombadil.infradead.org> References: <20200415004353.130248-1-walken@google.com> <20200415004353.130248-10-walken@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200415004353.130248-10-walken@google.com> 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, Apr 14, 2020 at 05:43:52PM -0700, Michel Lespinasse wrote: > Use lockdep_assert_held when asserting that mmap_sem is held. > > Using this instead of rwsem_is_locked makes the assertions more > tolerant of future changes to the lock type. Somebody pointed out on an earlier iteration of this patch set that rwsem_is_locked() is enabled on all rwsems whereas lockdep_assert_held() is only enabled when lockdep is enabled, which is not production setups. How about this? static inline void mm_assert_locked(struct mm_struct *mm) { if (IS_ENABLED(CONFIG_LOCKDEP) && debug_locks) VM_BUG_ON_MM(!lockdep_is_held(&mm->mmap_sem), mm); else VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_sem), mm); }