tracing: Change tracing_pipe_fops() to rely on tracing_get_cpu()

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>
This commit is contained in:
Oleg Nesterov 2013-07-23 17:25:57 +02:00 committed by Steven Rostedt
parent 649e9c70da
commit 15544209cb

View File

@ -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);