kprobes: retry blocked optprobe in do_free_cleaned_kprobes

Once the aggrprobe is fully reverted in do_free_cleaned_kprobes(), retry
optimize_kprobe() on that sibling so it can return to OPTIMIZED.

Also remove the stale comment in __disarm_kprobe().

Link: https://lore.kernel.org/all/349359900266B25F+20260115023804.3951960-2-hongao@uniontech.com/
Signed-off-by: hongao <hongao@uniontech.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index ab8f9fc1f0d1724033e4ceb6c56aa5d90f34ff8c..1bd84d3b481775689e2aae78bd22ff808d3449b5 100644 (file)
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -516,6 +516,7 @@ static LIST_HEAD(freeing_list);
 
 static void kprobe_optimizer(struct work_struct *work);
 static DECLARE_DELAYED_WORK(optimizing_work, kprobe_optimizer);
+static void optimize_kprobe(struct kprobe *p);
 #define OPTIMIZE_DELAY 5
 
 /*
@@ -593,6 +594,17 @@ static void do_free_cleaned_kprobes(void)
                         */
                        continue;
                }
+
+               /*
+                * The aggregator was holding back another probe while it sat on the
+                * unoptimizing/freeing lists.  Now that the aggregator has been fully
+                * reverted we can safely retry the optimization of that sibling.
+                */
+
+               struct kprobe *_p = get_optimized_kprobe(op->kp.addr);
+               if (unlikely(_p))
+                       optimize_kprobe(_p);
+
                free_aggr_kprobe(&op->kp);
        }
 }
@@ -1002,12 +1014,6 @@ static void __disarm_kprobe(struct kprobe *p, bool reopt)
                if (unlikely(_p) && reopt)
                        optimize_kprobe(_p);
        }
-       /*
-        * TODO: Since unoptimization and real disarming will be done by
-        * the worker thread, we can not check whether another probe are
-        * unoptimized because of this probe here. It should be re-optimized
-        * by the worker thread.
-        */
 }
 
 #else /* !CONFIG_OPTPROBES */