From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755774Ab3GVNtA (ORCPT ); Mon, 22 Jul 2013 09:49:00 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47687 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755699Ab3GVNs6 (ORCPT ); Mon, 22 Jul 2013 09:48:58 -0400 Date: Mon, 22 Jul 2013 15:43:48 +0200 From: Oleg Nesterov To: Steven Rostedt , Masami Hiramatsu Cc: Alexander Z Lam , David Sharp , Frederic Weisbecker , Ingo Molnar , Vaibhav Nagarnaik , "zhangwei(Jovi)" , linux-kernel@vger.kernel.org Subject: [PATCH 3/7] tracing: Change tracing_buffers_fops to rely on tracing_get_cpu() Message-ID: <20130722134348.GA18365@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130722134313.GA18328@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org tracing_buffers_open() is racy, the memory inode->i_private points to can be already freed. Change debugfs_create_file("trace_pipe_raw", data) caller to pass "data = tr", tracing_buffers_open() can use tracing_get_cpu(). Change debugfs_create_file("snapshot_raw_fops", data) caller too, this file uses tracing_buffers_open/release. Signed-off-by: Oleg Nesterov --- kernel/trace/trace.c | 9 ++++----- 1 files changed, 4 insertions(+), 5 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 311581a..5a7fbc3 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4945,8 +4945,7 @@ static const struct file_operations snapshot_raw_fops = { static int tracing_buffers_open(struct inode *inode, struct file *filp) { - struct trace_cpu *tc = inode->i_private; - struct trace_array *tr = tc->tr; + struct trace_array *tr = inode->i_private; struct ftrace_buffer_info *info; int ret; @@ -4965,7 +4964,7 @@ static int tracing_buffers_open(struct inode *inode, struct file *filp) mutex_lock(&trace_types_lock); info->iter.tr = tr; - info->iter.cpu_file = tc->cpu; + info->iter.cpu_file = tracing_get_cpu(inode); info->iter.trace = tr->current_trace; info->iter.trace_buffer = &tr->trace_buffer; info->spare = NULL; @@ -5572,7 +5571,7 @@ tracing_init_debugfs_percpu(struct trace_array *tr, long cpu) &data->trace_cpu, cpu, &tracing_fops); trace_create_cpu_file("trace_pipe_raw", 0444, d_cpu, - &data->trace_cpu, cpu, &tracing_buffers_fops); + tr, cpu, &tracing_buffers_fops); trace_create_cpu_file("stats", 0444, d_cpu, &data->trace_cpu, cpu, &tracing_stats_fops); @@ -5585,7 +5584,7 @@ tracing_init_debugfs_percpu(struct trace_array *tr, long cpu) &data->trace_cpu, cpu, &snapshot_fops); trace_create_cpu_file("snapshot_raw", 0444, d_cpu, - &data->trace_cpu, cpu, &snapshot_raw_fops); + tr, cpu, &snapshot_raw_fops); #endif } -- 1.5.5.1