Add a counter to kick_kprobe_optimizer() to detect any
additional register/unregister kprobes and postpone
kprobe_optimizer() until a bunch of probes are registered.
This might improve some long waiting unregistration process
for bunch of kprobes.
Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
---
kernel/kprobes.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index a2c755e79be7..0dacdcecc90f 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -465,6 +465,7 @@ static struct kprobe *get_optimized_kprobe(unsigned long addr)
static LIST_HEAD(optimizing_list);
static LIST_HEAD(unoptimizing_list);
static LIST_HEAD(freeing_list);
+static int kprobe_optimizer_queue_update;
static void kprobe_optimizer(struct work_struct *work);
static DECLARE_DELAYED_WORK(optimizing_work, kprobe_optimizer);
@@ -555,12 +556,22 @@ static void do_free_cleaned_kprobes(void)
static void kick_kprobe_optimizer(void)
{
schedule_delayed_work(&optimizing_work, OPTIMIZE_DELAY);
+ kprobe_optimizer_queue_update++;
}
/* Kprobe jump optimizer */
static void kprobe_optimizer(struct work_struct *work)
{
mutex_lock(&kprobe_mutex);
+
+ /*
+ * If new kprobe is queued in optimized/unoptimized list while
+ * OPTIMIZE_DELAY waiting period, wait again for a series of
+ * probes registration/unregistrations.
+ */
+ if (kprobe_optimizer_queue_update > 1)
+ goto end;
+
cpus_read_lock();
mutex_lock(&text_mutex);
/* Lock modules while optimizing kprobes */
@@ -593,6 +604,8 @@ static void kprobe_optimizer(struct work_struct *work)
mutex_unlock(&text_mutex);
cpus_read_unlock();
+end:
+ kprobe_optimizer_queue_update = 0;
/* Step 5: Kick optimizer again if needed */
if (!list_empty(&optimizing_list) || !list_empty(&unoptimizing_list))
kick_kprobe_optimizer();
