1 files changed, 49 insertions, 3 deletions

diff --git a/mm/kasan/quarantine.c b/mm/kasan/quarantine.c
index 0a9def8ce5e8..8ef098f52622 100644
--- a/mm/kasan/quarantine.c
+++ b/mm/kasan/quarantine.c
@@ -99,6 +99,17 @@ static unsigned long quarantine_size;
 static DEFINE_RAW_SPINLOCK(quarantine_lock);
 DEFINE_STATIC_SRCU(remove_cache_srcu);
 
+#ifdef CONFIG_PREEMPT_RT
+struct cpu_shrink_qlist {
+	raw_spinlock_t lock;
+	struct qlist_head qlist;
+};
+
+static DEFINE_PER_CPU(struct cpu_shrink_qlist, shrink_qlist) = {
+	.lock = __RAW_SPIN_LOCK_UNLOCKED(shrink_qlist.lock),
+};
+#endif
+
 /* Maximum size of the global queue. */
 static unsigned long quarantine_max_size;
 
@@ -308,10 +319,31 @@ static void qlist_move_cache(struct qlist_head *from,
 	}
 }
 
-static void per_cpu_remove_cache(void *arg)
+#ifndef CONFIG_PREEMPT_RT
+static void __per_cpu_remove_cache(struct qlist_head *q, void *arg)
 {
 	struct kmem_cache *cache = arg;
 	struct qlist_head to_free = QLIST_INIT;
+
+	qlist_move_cache(q, &to_free, cache);
+	qlist_free_all(&to_free, cache);
+}
+#else
+static void __per_cpu_remove_cache(struct qlist_head *q, void *arg)
+{
+	struct kmem_cache *cache = arg;
+	unsigned long flags;
+	struct cpu_shrink_qlist *sq;
+
+	sq = this_cpu_ptr(&shrink_qlist);
+	raw_spin_lock_irqsave(&sq->lock, flags);
+	qlist_move_cache(q, &sq->qlist, cache);
+	raw_spin_unlock_irqrestore(&sq->lock, flags);
+}
+#endif
+
+static void per_cpu_remove_cache(void *arg)
+{
 	struct qlist_head *q;
 
 	q = this_cpu_ptr(&cpu_quarantine);
@@ -322,8 +354,7 @@ static void per_cpu_remove_cache(void *arg)
 	 */
 	if (READ_ONCE(q->offline))
 		return;
-	qlist_move_cache(q, &to_free, cache);
-	qlist_free_all(&to_free, cache);
+	__per_cpu_remove_cache(q, arg);
 }
 
 /* Free all quarantined objects belonging to cache. */
@@ -341,6 +372,21 @@ void kasan_quarantine_remove_cache(struct kmem_cache *cache)
 	 */
 	on_each_cpu(per_cpu_remove_cache, cache, 1);
 
+#ifdef CONFIG_PREEMPT_RT
+	{
+		int cpu;
+		struct cpu_shrink_qlist *sq;
+
+		for_each_online_cpu(cpu) {
+			sq = per_cpu_ptr(&shrink_qlist, cpu);
+			raw_spin_lock_irqsave(&sq->lock, flags);
+			qlist_move_cache(&sq->qlist, &to_free, cache);
+			raw_spin_unlock_irqrestore(&sq->lock, flags);
+		}
+		qlist_free_all(&to_free, cache);
+	}
+#endif
+
 	raw_spin_lock_irqsave(&quarantine_lock, flags);
 	for (i = 0; i < QUARANTINE_BATCHES; i++) {
 		if (qlist_empty(&global_quarantine[i]))