Commit c521efd1 authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt
Browse files

tracing: Add pipe_close interface 



An ftrace plugin can add a pipe_open interface when the user opens
trace_pipe. But if the plugin allocates something within the pipe_open
it can not free it because there exists no pipe_close. The hook to
the trace file open has a corresponding close. The closing of the
trace_pipe file should also have a corresponding close.

Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 6ec22f9b

kernel/trace/trace.c

+4 −0
Original line number Diff line number Diff line
@@ -2898,6 +2898,10 @@ static int tracing_release_pipe(struct inode *inode, struct file *file) 
	else

		cpumask_clear_cpu(iter->cpu_file, tracing_reader_cpumask);





	if (iter->trace->pipe_open)

		iter->trace->pipe_close(iter);



	mutex_unlock(&trace_types_lock);



	free_cpumask_var(iter->started);

kernel/trace/trace.h

+2 −0
Original line number Diff line number Diff line
@@ -272,6 +272,7 @@ struct tracer_flags { 
 * @pipe_open: called when the trace_pipe file is opened

 * @wait_pipe: override how the user waits for traces on trace_pipe

 * @close: called when the trace file is released

 * @pipe_close: called when the trace_pipe file is released

 * @read: override the default read callback on trace_pipe

 * @splice_read: override the default splice_read callback on trace_pipe

 * @selftest: selftest to run on boot (see trace_selftest.c)
@@ -290,6 +291,7 @@ struct tracer { 
	void			(*pipe_open)(struct trace_iterator *iter);

	void			(*wait_pipe)(struct trace_iterator *iter);

	void			(*close)(struct trace_iterator *iter);

	void			(*pipe_close)(struct trace_iterator *iter);

	ssize_t			(*read)(struct trace_iterator *iter,

					struct file *filp, char __user *ubuf,

					size_t cnt, loff_t *ppos);

CRA Git | Maintained and supported by SUSTech CRA and CCSE