tracing: Erase irqsoff trace with empty write
authorBo Yan <byan@nvidia.com>
Mon, 18 Sep 2017 17:03:35 +0000 (10:03 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 5 Oct 2017 07:43:59 +0000 (09:43 +0200)
commit5fb4be27dac5f0ad925604acf4b5984fe8271551
treea0662dbc4228a7b9fa3a0a9f6e19f8235b55b033
parent97d402e6eed2f7d867a9f57d9d35a968c1440fe8
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: 4acd4d00f ("tracing: give easy way to clear trace buffer")
Signed-off-by: Bo Yan <byan@nvidia.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kernel/trace/trace.c