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 A98AEC2D0DB for ; Thu, 30 Jan 2020 18:42:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 820A8205F4 for ; Thu, 30 Jan 2020 18:42:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580409762; bh=GOS1qZvCtnVV92X2RUs0Xx56D0YfKguWqkXghm3ygQE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=qrICg8OF3+Kuun8swINQOmJpDzaw2N8fT1zqJLlWsY7m0msL+nk8pScNScJikUZtd JJgzg2NAUPifRqTzEzAvB65GAUi3kqhkHWNk/s2b1Dva2IczwGIAj+yMru8Y1nVo5Y 1yzKhIHOSRnVKV+rTdfhruxdoz6Bp3twhowhC0tg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730437AbgA3Smk (ORCPT ); Thu, 30 Jan 2020 13:42:40 -0500 Received: from mail.kernel.org ([198.145.29.99]:50920 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730399AbgA3Smg (ORCPT ); Thu, 30 Jan 2020 13:42:36 -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 4BC092083E; Thu, 30 Jan 2020 18:42:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580409755; bh=GOS1qZvCtnVV92X2RUs0Xx56D0YfKguWqkXghm3ygQE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UlQeN+Z9JhbOP9EQ+nlXb4jLQGGlZMsoR58kHzJ0Vx+e6lb77Wi4ec82MdRFo5fCk dODBY1vHNiUSRG6RfsgK8uLptpFugFQ1Xb9l0atnsur+I3PzAMkhM2fkaxD0zH2oYj f8ULcqCPBejuh1nZK96hDruDBFxjzIY7xcOhh4fc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Martin Fuzzey , Todd Kjos Subject: [PATCH 5.4 021/110] binder: fix log spam for existing debugfs file creation. Date: Thu, 30 Jan 2020 19:37:57 +0100 Message-Id: <20200130183617.460576374@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200130183613.810054545@linuxfoundation.org> References: <20200130183613.810054545@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 @@ -5203,10 +5203,11 @@ 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); @@ -5239,19 +5240,24 @@ 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, @@ -5259,19 +5265,16 @@ 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); @@ -5281,10 +5284,8 @@ 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); } }