ftrace/kprobe: Show the maxactive number on kprobe_events

commit 6a13a0d7b4d1171ef9b80ad69abc37e1daa941b3 upstream.

Show maxactive parameter on kprobe_events.
This allows user to save the current configuration and
restore it without losing maxactive parameter.

Link: http://lkml.kernel.org/r/4762764a-6df7-bc93-ed60-e336146dce1f@gmail.com
Link: http://lkml.kernel.org/r/158503528846.22706.5549974121212526020.stgit@devnote2
Cc: stable@vger.kernel.org
Fixes: 696ced4fb1d76 ("tracing/kprobes: expose maxactive for kretprobe in kprobe_events")
Reported-by: Taeung Song <treeze.taeung@gmail.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 3f54dc2f6e1c6ec5726e6c510277ff8198333a9e..2f0f7fcee73e6c534705df160adc6c024fa5c953 100644 (file)
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -918,6 +918,8 @@ static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev)
        int i;
 
        seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p');
+       if (trace_kprobe_is_return(tk) && tk->rp.maxactive)
+               seq_printf(m, "%d", tk->rp.maxactive);
        seq_printf(m, ":%s/%s", trace_probe_group_name(&tk->tp),
                                trace_probe_name(&tk->tp));