Merge tag 'probes-v7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull kprobes updates from Masami Hiramatsu:

 - Use a dedicated kernel thread to optimize the kprobes instead of
   using workqueue thread. Since the kprobe optimizer waits a long time
   for synchronize_rcu_task(), it can block other workers in the same
   queue if it uses a workqueue.

 - kprobe-events: return immediately if no new probe events are
   specified on the kernel command line at boot time. This shortens
   the kernel boot time.

 - When a kprobe is fully removed from the kernel code, retry optimizing
   another kprobe which is blocked by that kprobe.

* tag 'probes-v7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  kprobes: Use dedicated kthread for kprobe optimizer
  tracing: kprobe-event: Return directly when trace kprobes is empty
  kprobes: retry blocked optprobe in do_free_cleaned_kprobes

1 files changed, 4 insertions, 0 deletions

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 061658518605..b4f62d2e41ed 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -82,6 +82,7 @@ static struct trace_kprobe *to_trace_kprobe(struct dyn_event *ev)
 #define for_each_trace_kprobe(pos, dpos)	\
 	for_each_dyn_event(dpos)		\
 		if (is_trace_kprobe(dpos) && (pos = to_trace_kprobe(dpos)))
+#define trace_kprobe_list_empty() list_empty(&dyn_event_list)
 
 static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk)
 {
@@ -1982,6 +1983,9 @@ static __init void enable_boot_kprobe_events(void)
 	struct trace_kprobe *tk;
 	struct dyn_event *pos;
 
+	if (trace_kprobe_list_empty())
+		return;
+
 	guard(mutex)(&event_mutex);
 	for_each_trace_kprobe(tk, pos) {
 		list_for_each_entry(file, &tr->events, list)