The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 6a13a0d7b4d1171ef9b80ad69abc37e1daa941b3 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu <mhiramat@xxxxxxxxxx> Date: Tue, 24 Mar 2020 16:34:48 +0900 Subject: [PATCH] ftrace/kprobe: Show the maxactive number on kprobe_events 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@xxxxxxxxx Link: http://lkml.kernel.org/r/158503528846.22706.5549974121212526020.stgit@devnote2 Cc: stable@xxxxxxxxxxxxxxx Fixes: 696ced4fb1d76 ("tracing/kprobes: expose maxactive for kretprobe in kprobe_events") Reported-by: Taeung Song <treeze.taeung@xxxxxxxxx> Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx> Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 362cca52f5de..d0568af4a0ef 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -1078,6 +1078,8 @@ 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));
