lkml.org 
[lkml]   [2013]   [Jul]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[for-next-3.11][PATCH 2/9] tracing: Change tracing_pipe_fops() to rely on tracing_get_cpu()
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



\
 
 \ /
  Last update: 2013-07-24 18:21    [W:0.065 / U:1.068 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site