From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758801Ab3GZNFS (ORCPT ); Fri, 26 Jul 2013 09:05:18 -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 S1757620Ab3GZNFN (ORCPT ); Fri, 26 Jul 2013 09:05:13 -0400 X-Authority-Analysis: v=2.0 cv=e9yEuNV/ c=1 sm=0 a=Sro2XwOs0tJUSHxCKfOySw==:17 a=Drc5e87SC40A:10 a=Ciwy3NGCPMMA:10 a=mYMHgPtk6LcA:10 a=5SG0PmZfjMsA:10 a=bbbx4UPp9XUA:10 a=meVymXHHAAAA:8 a=KGjhK52YXX0A:10 a=WccrhnkeSn8A:10 a=20KFwNOVAAAA:8 a=VwQbUJbxAAAA:8 a=XvuyIiCH_Q-Y7ANRKWUA:9 a=jEp0ucaQiEUA:10 a=jeBq3FmKZ4MA:10 a=Sro2XwOs0tJUSHxCKfOySw==:117 X-Cloudmark-Score: 0 X-Authenticated-User: X-Originating-IP: 67.255.60.225 Message-Id: <20130726130512.628127693@goodmis.org> User-Agent: quilt/0.60-1 Date: Fri, 26 Jul 2013 09:03:31 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Linus Torvalds , Ingo Molnar , Andrew Morton , Oleg Nesterov Subject: [PATCH 4/9] tracing: Change tracing_stats_fops to rely on tracing_get_cpu() References: <20130726130327.911599518@goodmis.org> Content-Disposition: inline; filename=0004-tracing-Change-tracing_stats_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_generic_tc() is racy, the memory inode->i_private points to can be already freed. 1. Change one of its users, tracing_stats_fops, to use tracing_*_generic_tr() instead. 2. Change trace_create_cpu_file("stats", data) to pass "data = tr". 3. Change tracing_stats_read() to use tracing_get_cpu(). Link: http://lkml.kernel.org/r/20130723152603.GA23727@redhat.com Signed-off-by: Oleg Nesterov Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 30c058a..e29dc8f 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2982,7 +2982,6 @@ static int tracing_open_generic_tr(struct inode *inode, struct file *filp) filp->private_data = inode->i_private; return 0; - } static int tracing_open_generic_tc(struct inode *inode, struct file *filp) @@ -5285,14 +5284,14 @@ static ssize_t tracing_stats_read(struct file *filp, char __user *ubuf, size_t count, loff_t *ppos) { - struct trace_cpu *tc = filp->private_data; - struct trace_array *tr = tc->tr; + struct inode *inode = file_inode(filp); + struct trace_array *tr = inode->i_private; struct trace_buffer *trace_buf = &tr->trace_buffer; + int cpu = tracing_get_cpu(inode); struct trace_seq *s; unsigned long cnt; unsigned long long t; unsigned long usec_rem; - int cpu = tc->cpu; s = kmalloc(sizeof(*s), GFP_KERNEL); if (!s) @@ -5345,10 +5344,10 @@ tracing_stats_read(struct file *filp, char __user *ubuf, } static const struct file_operations tracing_stats_fops = { - .open = tracing_open_generic_tc, + .open = tracing_open_generic_tr, .read = tracing_stats_read, .llseek = generic_file_llseek, - .release = tracing_release_generic_tc, + .release = tracing_release_generic_tr, }; #ifdef CONFIG_DYNAMIC_FTRACE @@ -5578,7 +5577,7 @@ tracing_init_debugfs_percpu(struct trace_array *tr, long cpu) tr, cpu, &tracing_buffers_fops); trace_create_cpu_file("stats", 0444, d_cpu, - &data->trace_cpu, cpu, &tracing_stats_fops); + tr, cpu, &tracing_stats_fops); trace_create_cpu_file("buffer_size_kb", 0444, d_cpu, &data->trace_cpu, cpu, &tracing_entries_fops); -- 1.7.10.4