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Commit 15544209 authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Steven Rostedt
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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: default avatarOleg Nesterov <oleg@redhat.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 649e9c70

kernel/trace/trace.c

+7 −9
Original line number Diff line number Diff line
@@ -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 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp) 
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);