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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 3F351C35240 for ; Thu, 30 Jan 2020 18:54:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 17E862082E for ; Thu, 30 Jan 2020 18:54:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580410468; bh=IzDMZNQl3J1nGNsNXmPv0XusuU1RExicvphwbiLdAOQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=XyoE7Yb6x9JTIPcWIYtTzAxiE8tEzNaaM/YRJlE9I2PkfppcSJYozxbMVNNPuE1C7 B5FMpzuPJQBZtSLanBqUPYlajS7+OQU3Yxvp5bjmb1XsAmcmuCFu9+PyHjmkJ1c5aW fY85f95rCr9+NPkzYce9FA8MmPiUL6HvGFU6I6tY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729914AbgA3SkT (ORCPT ); Thu, 30 Jan 2020 13:40:19 -0500 Received: from mail.kernel.org ([198.145.29.99]:47794 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728000AbgA3SkR (ORCPT ); Thu, 30 Jan 2020 13:40:17 -0500 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 1700420702; Thu, 30 Jan 2020 18:40:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580409616; bh=IzDMZNQl3J1nGNsNXmPv0XusuU1RExicvphwbiLdAOQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gaSQtA8TDuKGt3r66yE+cQoFB9kRR14geqKhGlHaEORnv6+p8Zsg6u2QWW0xPqiXx VKiBEZ3EvBLNip0vpPWacdAXStMFFdUh7RRryNUgwxd9mWWb1pCuWC83QsGDC14bMv GSlI/U7SAgbAegnet32WNmy1i0uUkbUbqWfnvL50= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Martin Fuzzey , Todd Kjos Subject: [PATCH 5.5 21/56] binder: fix log spam for existing debugfs file creation. Date: Thu, 30 Jan 2020 19:38:38 +0100 Message-Id: <20200130183613.111465806@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200130183608.849023566@linuxfoundation.org> References: <20200130183608.849023566@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Martin Fuzzey commit eb143f8756e77c8fcfc4d574922ae9efd3a43ca9 upstream. Since commit 43e23b6c0b01 ("debugfs: log errors when something goes wrong") debugfs logs attempts to create existing files. However binder attempts to create multiple debugfs files with the same name when a single PID has multiple contexts, this leads to log spamming during an Android boot (17 such messages during boot on my system). Fix this by checking if we already know the PID and only create the debugfs entry for the first context per PID. Do the same thing for binderfs for symmetry. Signed-off-by: Martin Fuzzey Acked-by: Todd Kjos Fixes: 43e23b6c0b01 ("debugfs: log errors when something goes wrong") Cc: stable Link: https://lore.kernel.org/r/1578671054-5982-1-git-send-email-martin.fuzzey@flowbird.group Signed-off-by: Greg Kroah-Hartman --- drivers/android/binder.c | 37 +++++++++++++++++++------------------ 1 file changed, 19 insertions(+), 18 deletions(-) --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -5199,10 +5199,11 @@ err_bad_arg: static int binder_open(struct inode *nodp, struct file *filp) { - struct binder_proc *proc; + struct binder_proc *proc, *itr; struct binder_device *binder_dev; struct binderfs_info *info; struct dentry *binder_binderfs_dir_entry_proc = NULL; + bool existing_pid = false; binder_debug(BINDER_DEBUG_OPEN_CLOSE, "%s: %d:%d\n", __func__, current->group_leader->pid, current->pid); @@ -5235,19 +5236,24 @@ static int binder_open(struct inode *nod filp->private_data = proc; mutex_lock(&binder_procs_lock); + hlist_for_each_entry(itr, &binder_procs, proc_node) { + if (itr->pid == proc->pid) { + existing_pid = true; + break; + } + } hlist_add_head(&proc->proc_node, &binder_procs); mutex_unlock(&binder_procs_lock); - if (binder_debugfs_dir_entry_proc) { + if (binder_debugfs_dir_entry_proc && !existing_pid) { char strbuf[11]; snprintf(strbuf, sizeof(strbuf), "%u", proc->pid); /* - * proc debug entries are shared between contexts, so - * this will fail if the process tries to open the driver - * again with a different context. The priting code will - * anyway print all contexts that a given PID has, so this - * is not a problem. + * proc debug entries are shared between contexts. + * Only create for the first PID to avoid debugfs log spamming + * The printing code will anyway print all contexts for a given + * PID so this is not a problem. */ proc->debugfs_entry = debugfs_create_file(strbuf, 0444, binder_debugfs_dir_entry_proc, @@ -5255,19 +5261,16 @@ static int binder_open(struct inode *nod &proc_fops); } - if (binder_binderfs_dir_entry_proc) { + if (binder_binderfs_dir_entry_proc && !existing_pid) { char strbuf[11]; struct dentry *binderfs_entry; snprintf(strbuf, sizeof(strbuf), "%u", proc->pid); /* * Similar to debugfs, the process specific log file is shared - * between contexts. If the file has already been created for a - * process, the following binderfs_create_file() call will - * fail with error code EEXIST if another context of the same - * process invoked binder_open(). This is ok since same as - * debugfs, the log file will contain information on all - * contexts of a given PID. + * between contexts. Only create for the first PID. + * This is ok since same as debugfs, the log file will contain + * information on all contexts of a given PID. */ binderfs_entry = binderfs_create_file(binder_binderfs_dir_entry_proc, strbuf, &proc_fops, (void *)(unsigned long)proc->pid); @@ -5277,10 +5280,8 @@ static int binder_open(struct inode *nod int error; error = PTR_ERR(binderfs_entry); - if (error != -EEXIST) { - pr_warn("Unable to create file %s in binderfs (error %d)\n", - strbuf, error); - } + pr_warn("Unable to create file %s in binderfs (error %d)\n", + strbuf, error); } }