From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758908Ab3GZNHU (ORCPT ); Fri, 26 Jul 2013 09:07:20 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:14483 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758258Ab3GZNFO (ORCPT ); Fri, 26 Jul 2013 09:05:14 -0400 X-Authority-Analysis: v=2.0 cv=e9yEuNV/ c=1 sm=0 a=Sro2XwOs0tJUSHxCKfOySw==:17 a=Drc5e87SC40A:10 a=Ciwy3NGCPMMA:10 a=1aBXN6OI0oIA:10 a=5SG0PmZfjMsA:10 a=bbbx4UPp9XUA:10 a=meVymXHHAAAA:8 a=KGjhK52YXX0A:10 a=9gBtJG8FnjkA:10 a=20KFwNOVAAAA:8 a=VwQbUJbxAAAA:8 a=ayC55rCoAAAA:8 a=0kbfjC1OccZKM1oZNXEA:9 a=jEp0ucaQiEUA:10 a=jeBq3FmKZ4MA:10 a=q9mC2fbAJx8A:10 a=Sro2XwOs0tJUSHxCKfOySw==:117 X-Cloudmark-Score: 0 X-Authenticated-User: X-Originating-IP: 67.255.60.225 Message-Id: <20130726130512.305024273@goodmis.org> User-Agent: quilt/0.60-1 Date: Fri, 26 Jul 2013 09:03:29 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Linus Torvalds , Ingo Molnar , Andrew Morton , Oleg Nesterov Subject: [PATCH 2/9] tracing: Change tracing_pipe_fops() to rely on tracing_get_cpu() References: <20130726130327.911599518@goodmis.org> Content-Disposition: inline; filename=0002-tracing-Change-tracing_pipe_fops-to-rely-on-tracing_.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Oleg Nesterov tracing_open_pipe() is racy, the memory inode->i_private points to can be already freed. Change debugfs_create_file("trace_pipe", data) callers to to pass "data = tr", tracing_open_pipe() can use tracing_get_cpu(). Link: http://lkml.kernel.org/r/20130723152557.GA23717@redhat.com Signed-off-by: Oleg Nesterov Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index cfff63c..51a99ef 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3959,8 +3959,7 @@ tracing_max_lat_write(struct file *filp, const char __user *ubuf, static int tracing_open_pipe(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 trace_iterator *iter; int ret = 0; @@ -4006,9 +4005,9 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp) if (trace_clocks[tr->clock_id].in_ns) iter->iter_flags |= TRACE_FILE_TIME_IN_NS; - iter->cpu_file = tc->cpu; - iter->tr = tc->tr; - iter->trace_buffer = &tc->tr->trace_buffer; + iter->tr = tr; + iter->trace_buffer = &tr->trace_buffer; + iter->cpu_file = tracing_get_cpu(inode); mutex_init(&iter->mutex); filp->private_data = iter; @@ -4031,8 +4030,7 @@ fail: static int tracing_release_pipe(struct inode *inode, struct file *file) { struct trace_iterator *iter = file->private_data; - struct trace_cpu *tc = inode->i_private; - struct trace_array *tr = tc->tr; + struct trace_array *tr = inode->i_private; mutex_lock(&trace_types_lock); @@ -5571,7 +5569,7 @@ tracing_init_debugfs_percpu(struct trace_array *tr, long cpu) /* per cpu trace_pipe */ trace_create_cpu_file("trace_pipe", 0444, d_cpu, - &data->trace_cpu, cpu, &tracing_pipe_fops); + tr, cpu, &tracing_pipe_fops); /* per cpu trace */ trace_create_cpu_file("trace", 0644, d_cpu, @@ -6157,7 +6155,7 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer) (void *)&tr->trace_cpu, &tracing_fops); trace_create_file("trace_pipe", 0444, d_tracer, - (void *)&tr->trace_cpu, &tracing_pipe_fops); + tr, &tracing_pipe_fops); trace_create_file("buffer_size_kb", 0644, d_tracer, (void *)&tr->trace_cpu, &tracing_entries_fops); -- 1.7.10.4