[RFC PATCH 04/11] tracing: kprobes: Register to dynevent earlier stage

Masami Hiramatsu
2019-06-21T16:18:47Z

Register kprobe event to dynevent in subsys_initcall level.
This will allow kernel to register new kprobe events in
fs_initcall level via trace_run_command.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
kernel/trace/trace_kprobe.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 3eb03cf880e1..5166a12a9d49 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1547,11 +1547,12 @@ static __init void setup_boot_kprobe_events(void)
enable_boot_kprobe_events();
}

-/* Make a tracefs interface for controlling probe points */
-static __init int init_kprobe_trace(void)
+/*
+ * Register dynevent at subsys_initcall. This allows kernel to setup kprobe
+ * events in fs_initcall without tracefs.
+ */
+static __init int init_kprobe_trace_early(void)
{
- struct dentry *d_tracer;
- struct dentry *entry;
int ret;

ret = dyn_event_register(&trace_kprobe_ops);
@@ -1561,6 +1562,16 @@ static __init int init_kprobe_trace(void)
if (register_module_notifier(&trace_kprobe_module_nb))
return -EINVAL;

+ return 0;
+}
+subsys_initcall(init_kprobe_trace_early);
+
+/* Make a tracefs interface for controlling probe points */
+static __init int init_kprobe_trace(void)
+{
+ struct dentry *d_tracer;
+ struct dentry *entry;
+
d_tracer = tracing_init_dentry();
if (IS_ERR(d_tracer))
return 0;