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=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 2D468C433FF for ; Thu, 8 Aug 2019 06:42:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E74E02187F for ; Thu, 8 Aug 2019 06:42:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565246560; bh=QkRNK9YOfVlVjw60w9/iF0cccnbeZTBNkhlnMmoHZSo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=1eC0uGrFyXJz704Y+m8rieGKOXIndQwQlgz7r/+hmTGN/PKdhp6gYTtcEGxtB7shc TRpktesG2NbLgWEtbZ6IYMbT47JpXC9QEtB9mfUOndyBOzv4AovLTxjQFHFw6hSPaT GbSfBYNLhyxecvB5ZgQeHBRt/YaNoKhnNuLe8OmE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731013AbfHHGmi (ORCPT ); Thu, 8 Aug 2019 02:42:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:42420 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726359AbfHHGmi (ORCPT ); Thu, 8 Aug 2019 02:42:38 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 EF2DD20880; Thu, 8 Aug 2019 06:42:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565246557; bh=QkRNK9YOfVlVjw60w9/iF0cccnbeZTBNkhlnMmoHZSo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=TEEQWuy6TSpOEZMwvSr5bheEo6c0goUwfwhY6u81BONopHxyVvbgi4ZhzicU1UCZU QXbtoqaRmyPdA18atxTjX/YtfT5T8mPLvFzvbzRdeu4qtSO+eZw4b0Gf4W97UvfZSm L8jVUt4qJ/cpM3lWvFw3sZyg80FMbtaTWDY/b8Qo= Date: Thu, 8 Aug 2019 08:42:35 +0200 From: Greg Kroah-Hartman To: Tejun Heo Cc: Tony Lindgren , linux-kernel@vger.kernel.org, Andrea Arcangeli , Russell King , linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org Subject: Re: [PATCH] kernfs: fix memleak in kernel_ops_readdir() Message-ID: <20190808064235.GC26197@kroah.com> References: <20190805173404.GF136335@devbig004.ftw2.facebook.com> <20190807132928.GD5443@atomide.com> <20190807184518.GP136335@devbig004.ftw2.facebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190807184518.GP136335@devbig004.ftw2.facebook.com> User-Agent: Mutt/1.12.1 (2019-06-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 07, 2019 at 11:45:18AM -0700, Tejun Heo wrote: > Hello, > > On Wed, Aug 07, 2019 at 06:29:28AM -0700, Tony Lindgren wrote: > > Hi, > > > > * Tejun Heo [691231 23:00]: > > > From: Andrea Arcangeli > > > > > > If getdents64 is killed or hits on segfault, it'll leave cgroups > > > directories in sysfs pinned leaking memory because the kernfs node > > > won't be freed on rmdir and the parent neither. > > > > Somehow this causes a regression in Linux next for me where I'm seeing > > lots of sysfs entries now missing under /sys/bus/platform/devices. > > > > For example, I now only see one .serial entry show up in sysfs. > > Things work again if I revert commit cc798c83898e ("kernfs: fix memleak > > inkernel_ops_readdir()"). Any ideas why that would be? > > > > Below is a diff -u of ls /sys/bus/platform/devices for reference > > showing the missing entries with cc798c83898e. > > Ugh, you're right. It can get double-put cuz ctx->pos is put by > release too. Greg, sorry about the noise but can you please revert > the patch? I'll look into why this looked like memory leak from > slabinfo side. Now reverted, thanks. greg k-h