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=-11.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 850D3C33CAA for ; Thu, 23 Jan 2020 07:08:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5546524655 for ; Thu, 23 Jan 2020 07:08:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579763284; bh=KF+6TFrgjdCk7daC/uYjJcRbuE8TRoUpLGqNqzb1lkY=; h=Subject:To:From:Date:List-ID:From; b=EpofCkwXW4SIGa7CHxk84LCBWOonIEniekWfLtFrFFm34Swbpx52iZfz+aXaL2/4g 5NdEgahhDbNekkXoXVnBn3OGNvNKtybf2jiiZlVmnBUZD1mFDc6H/zkUTWuSf34OqD NJZCiJ74CpKuhku63lzMdpbiwKBTWMxUX89tuJeQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725785AbgAWHID (ORCPT ); Thu, 23 Jan 2020 02:08:03 -0500 Received: from mail.kernel.org ([198.145.29.99]:41376 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725535AbgAWHID (ORCPT ); Thu, 23 Jan 2020 02:08:03 -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 5BA2224673; Thu, 23 Jan 2020 07:08:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579763282; bh=KF+6TFrgjdCk7daC/uYjJcRbuE8TRoUpLGqNqzb1lkY=; h=Subject:To:From:Date:From; b=j2zxrxTAeBcErEkdoeqbE0LoUSYZQQ5q6B99C7zeKWx+3kzMYw/Ou8reHb6v6lRlG 8vJd92d8/C2gPe5WqNT2rKP/U2l3Y03lMdvzHWIu16Kh9tYfnEJCm7f0b1WTaPGnBu ssd4JmPr8woH+Xu1MJLs7Hkw3itEBEK37Op+Tmlw= Subject: patch "binder: fix log spam for existing debugfs file creation." added to char-misc-next To: martin.fuzzey@flowbird.group, gregkh@linuxfoundation.org, stable@vger.kernel.org, tkjos@google.com From: Date: Thu, 23 Jan 2020 08:07:26 +0100 Message-ID: <15797632463180@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org This is a note to let you know that I've just added the patch titled binder: fix log spam for existing debugfs file creation. to my char-misc git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git in the char-misc-next branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will also be merged in the next major kernel release during the merge window. If you have any questions about this process, please let me know. >From eb143f8756e77c8fcfc4d574922ae9efd3a43ca9 Mon Sep 17 00:00:00 2001 From: Martin Fuzzey Date: Fri, 10 Jan 2020 16:44:01 +0100 Subject: binder: fix log spam for existing debugfs file creation. 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(-) diff --git a/drivers/android/binder.c b/drivers/android/binder.c index b2dad43dbf82..9fcc761031d8 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -5199,10 +5199,11 @@ static int binder_mmap(struct file *filp, struct vm_area_struct *vma) 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 *nodp, struct file *filp) 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 *nodp, struct file *filp) &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 *nodp, struct file *filp) 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); } } -- 2.25.0