[PATCH 01/21] tracing/kprobe: Set print format right after parsed command

From: Masami Hiramatsu
Date: Fri May 31 2019 - 11:20:34 EST


Set event call's print format right after parsed command for
simplifying (un)register_kprobe_event().

Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
---
kernel/trace/trace_kprobe.c | 25 +++++++++----------------
1 file changed, 9 insertions(+), 16 deletions(-)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 7958da2fd922..01fc49f08b70 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -272,6 +272,7 @@ static void free_trace_kprobe(struct trace_kprobe *tk)

kfree(tk->tp.call.class->system);
kfree(tk->tp.call.name);
+ kfree(tk->tp.call.print_fmt);
kfree(tk->symbol);
free_percpu(tk->nhit);
kfree(tk);
@@ -730,6 +731,10 @@ static int trace_kprobe_create(int argc, const char *argv[])
goto error; /* This can be -ENOMEM */
}

+ ret = traceprobe_set_print_fmt(&tk->tp, is_return);
+ if (ret < 0)
+ goto error;
+
ret = register_trace_kprobe(tk);
if (ret) {
trace_probe_log_set_index(1);
@@ -1416,18 +1421,14 @@ static int register_kprobe_event(struct trace_kprobe *tk)

init_trace_event_call(tk, call);

- if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0)
- return -ENOMEM;
ret = register_trace_event(&call->event);
- if (!ret) {
- kfree(call->print_fmt);
+ if (!ret)
return -ENODEV;
- }
+
ret = trace_add_event_call(call);
if (ret) {
pr_info("Failed to register kprobe event: %s\n",
trace_event_name(call));
- kfree(call->print_fmt);
unregister_trace_event(&call->event);
}
return ret;
@@ -1435,13 +1436,8 @@ static int register_kprobe_event(struct trace_kprobe *tk)

static int unregister_kprobe_event(struct trace_kprobe *tk)
{
- int ret;
-
/* tp->event is unregistered in trace_remove_event_call() */
- ret = trace_remove_event_call(&tk->tp.call);
- if (!ret)
- kfree(tk->tp.call.print_fmt);
- return ret;
+ return trace_remove_event_call(&tk->tp.call);
}

#ifdef CONFIG_PERF_EVENTS
@@ -1479,10 +1475,8 @@ create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
}

ret = __register_trace_kprobe(tk);
- if (ret < 0) {
- kfree(tk->tp.call.print_fmt);
+ if (ret < 0)
goto error;
- }

return &tk->tp.call;
error:
@@ -1503,7 +1497,6 @@ void destroy_local_trace_kprobe(struct trace_event_call *event_call)

__unregister_trace_kprobe(tk);

- kfree(tk->tp.call.print_fmt);
free_trace_kprobe(tk);
}
#endif /* CONFIG_PERF_EVENTS */