[PATCH] tracing/kprobes: 'nmissed' not showed correctly for kretprobe

From: Xiangyang Zhang
Date: Sat Dec 11 2021 - 10:00:53 EST


The 'nmissed' column of the 'kprobe_profile' file for kretprobe is
always zero, because 'nmissed' for kretprobe is maintained in
'tk->rp.nmissed' but not in 'tk->rp.kp.nmissed'

Fixes: c31ffb3ff633 ("tracing/kprobes: Factor out struct trace_probe")
Signed-off-by: Xiangyang Zhang <xyz.sun.ok@xxxxxxxxx>
---
kernel/trace/trace_kprobe.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index d10c01948e68..2b9de6826e94 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1175,15 +1175,17 @@ static int probes_profile_seq_show(struct seq_file *m, void *v)
{
struct dyn_event *ev = v;
struct trace_kprobe *tk;
+ unsigned long nmissed = 0;

if (!is_trace_kprobe(ev))
return 0;

tk = to_trace_kprobe(ev);
+ nmissed = tk->rp.handler ? tk->rp.nmissed : tk->rp.kp.nmissed;
seq_printf(m, " %-44s %15lu %15lu\n",
trace_probe_name(&tk->tp),
trace_kprobe_nhit(tk),
- tk->rp.kp.nmissed);
+ nmissed);

return 0;
}
--
2.25.1