Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 5fb4be27 authored by Bo Yan's avatar Bo Yan Committed by Greg Kroah-Hartman
Browse files

tracing: Erase irqsoff trace with empty write 

commit 8dd33bcb7050dd6f8c1432732f930932c9d3a33e upstream.

One convenient way to erase trace is "echo > trace". However, this
is currently broken if the current tracer is irqsoff tracer. This
is because irqsoff tracer use max_buffer as the default trace
buffer.

Set the max_buffer as the one to be cleared when it's the trace
buffer currently in use.

Link: http://lkml.kernel.org/r/1505754215-29411-1-git-send-email-byan@nvidia.com



Cc: <mingo@redhat.com>
Fixes: 4acd4d00 ("tracing: give easy way to clear trace buffer")
Signed-off-by: default avatarBo Yan <byan@nvidia.com>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 97d402e6

kernel/trace/trace.c

+8 −2
Original line number Diff line number Diff line
@@ -3569,11 +3569,17 @@ static int tracing_open(struct inode *inode, struct file *file) 
	/* If this file was open for write, then erase contents */

	if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {

		int cpu = tracing_get_cpu(inode);

		struct trace_buffer *trace_buf = &tr->trace_buffer;



#ifdef CONFIG_TRACER_MAX_TRACE

		if (tr->current_trace->print_max)

			trace_buf = &tr->max_buffer;

#endif



		if (cpu == RING_BUFFER_ALL_CPUS)

			tracing_reset_online_cpus(&tr->trace_buffer);

			tracing_reset_online_cpus(trace_buf);

		else

			tracing_reset(&tr->trace_buffer, cpu);

			tracing_reset(trace_buf, cpu);

	}



	if (file->f_mode & FMODE_READ) {