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=-10.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 42A03C433DF for ; Thu, 20 Aug 2020 20:43:09 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id EC86F2076E for ; Thu, 20 Aug 2020 20:43:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="XA5F3vbt" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EC86F2076E 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 6B5858D0034; Thu, 20 Aug 2020 16:43:08 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6681F8D0005; Thu, 20 Aug 2020 16:43:08 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 57CB18D0034; Thu, 20 Aug 2020 16:43:08 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0098.hostedemail.com [216.40.44.98]) by kanga.kvack.org (Postfix) with ESMTP id 420478D0005 for ; Thu, 20 Aug 2020 16:43:08 -0400 (EDT) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 00B29246E for ; Thu, 20 Aug 2020 20:43:07 +0000 (UTC) X-FDA: 77172121656.22.watch95_5e0f8cf27033 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin22.hostedemail.com (Postfix) with ESMTP id B608318038E60 for ; Thu, 20 Aug 2020 20:43:07 +0000 (UTC) X-HE-Tag: watch95_5e0f8cf27033 X-Filterd-Recvd-Size: 2598 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf10.hostedemail.com (Postfix) with ESMTP for ; Thu, 20 Aug 2020 20:43:07 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 07AD42076E; Thu, 20 Aug 2020 20:43:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597956186; bh=ix9BzHyMhh9j6vG1qYIhq2XvKRj9lGh7gqvOocKATrA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=XA5F3vbtJbV7w6HhBLVU4M65N/KzkEgozV7nPq7/E1mMcsrHrC2PZY16QZdIPAMIx paClQb1xGbud4bsJhpaF/kPbehKUenrQ9BViSP3FuS6ZvBe1hQUsLgIWBjE2iXJO+9 SaGlMJ+VEba5bHDxD1o/CAAzW+adkzSQExwovAoY= Date: Thu, 20 Aug 2020 13:43:05 -0700 From: Andrew Morton To: kernel test robot Cc: Linux Memory Management List , Chinwen Chang Subject: Re: [linux-next:master] BUILD REGRESSION 605cbf3d5f20470ec303b79feda3202935f4a142 Message-Id: <20200820134305.baa5ac2c1300a6b412a0c7c9@linux-foundation.org> In-Reply-To: <5f3edc64.qkHsk6Qli55TwDHw%lkp@intel.com> References: <5f3edc64.qkHsk6Qli55TwDHw%lkp@intel.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 X-Rspamd-Queue-Id: B608318038E60 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam01 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 Fri, 21 Aug 2020 04:26:12 +0800 kernel test robot wrote: > tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master > branch HEAD: 605cbf3d5f20470ec303b79feda3202935f4a142 Add linux-next specific files for 20200820 > > Error/Warning in current branch: > ... > > > fs/proc/task_mmu.c:947 show_smaps_rollup() error: double unlocked 'mm->mmap_lock' (orig line 879) This is code added by "mm: proc: smaps_rollup: do not stall write attempts on mmap_lock" (http://lkml.kernel.org/r/1597715898-3854-4-git-send-email-chinwen.chang@mediatek.com). I don't get it. : if (mmap_lock_is_contended(mm)) { : mmap_read_unlock(mm); : ret = mmap_read_lock_killable(mm); : if (ret) { : release_task_mempolicy(priv); : goto out_put_mm; : } Here the mmap_lock is again taken for read : ... : : } : /* Case 2 above */ : vma = vma->vm_next; : } : : ... : : mmap_read_unlock(mm); and here it's unlocked. I don't see a possibility for double-unlock?