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From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Ingo Molnar <mingo@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Oleg Nesterov <oleg@redhat.com>
Subject: [PATCH 2/9] tracing: Change tracing_pipe_fops() to rely on tracing_get_cpu()
Date: Fri, 26 Jul 2013 09:03:29 -0400	[thread overview]
Message-ID: <20130726130512.305024273@goodmis.org> (raw)
In-Reply-To: 20130726130327.911599518@goodmis.org

[-- Attachment #1: 0002-tracing-Change-tracing_pipe_fops-to-rely-on-tracing_.patch --]
[-- Type: text/plain, Size: 2455 bytes --]

From: Oleg Nesterov <oleg@redhat.com>

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 <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 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



  parent reply	other threads:[~2013-07-26 13:07 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-07-26 13:03 [PATCH 0/9] [GIT PULL] tracing: fixes Steven Rostedt
2013-07-26 13:03 ` [PATCH 1/9] tracing: Introduce trace_create_cpu_file() and tracing_get_cpu() Steven Rostedt
2013-07-26 13:03 ` Steven Rostedt [this message]
2013-07-26 13:03 ` [PATCH 3/9] tracing: Change tracing_buffers_fops to rely on tracing_get_cpu() Steven Rostedt
2013-07-26 13:03 ` [PATCH 4/9] tracing: Change tracing_stats_fops " Steven Rostedt
2013-07-26 13:03 ` [PATCH 5/9] tracing: Change tracing_entries_fops " Steven Rostedt
2013-07-26 13:03 ` [PATCH 6/9] tracing: Change tracing_fops/snapshot_fops " Steven Rostedt
2013-07-26 13:03 ` [PATCH 7/9] tracing: Kill trace_cpu struct/members Steven Rostedt
2013-07-26 13:03 ` [PATCH 8/9] ftrace: Add check for NULL regs if ops has SAVE_REGS set Steven Rostedt
2013-07-26 13:03 ` [PATCH 9/9] tracing: Remove locking trace_types_lock from tracing_reset_all_online_cpus() Steven Rostedt
2013-07-26 16:15   ` Arend van Spriel
2013-07-26 16:41     ` Steven Rostedt

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