1 files changed, 49 insertions, 0 deletions
diff --git a/include/linux/kasan-enabled.h b/include/linux/kasan-enabled.h
new file mode 100644
index 000000000000..9eca967d8526
--- /dev/null
+++ b/include/linux/kasan-enabled.h
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_KASAN_ENABLED_H
+#define _LINUX_KASAN_ENABLED_H
+
+#include <linux/static_key.h>
+
+#if defined(CONFIG_ARCH_DEFER_KASAN) || defined(CONFIG_KASAN_HW_TAGS)
+/*
+ * Global runtime flag for KASAN modes that need runtime control.
+ * Used by ARCH_DEFER_KASAN architectures and HW_TAGS mode.
+ */
+DECLARE_STATIC_KEY_FALSE(kasan_flag_enabled);
+
+/*
+ * Runtime control for shadow memory initialization or HW_TAGS mode.
+ * Uses static key for architectures that need deferred KASAN or HW_TAGS.
+ */
+static __always_inline bool kasan_enabled(void)
+{
+	return static_branch_likely(&kasan_flag_enabled);
+}
+
+static inline void kasan_enable(void)
+{
+	static_branch_enable(&kasan_flag_enabled);
+}
+#else
+/* For architectures that can enable KASAN early, use compile-time check. */
+static __always_inline bool kasan_enabled(void)
+{
+	return IS_ENABLED(CONFIG_KASAN);
+}
+
+static inline void kasan_enable(void) {}
+#endif /* CONFIG_ARCH_DEFER_KASAN || CONFIG_KASAN_HW_TAGS */
+
+#ifdef CONFIG_KASAN_HW_TAGS
+static inline bool kasan_hw_tags_enabled(void)
+{
+	return kasan_enabled();
+}
+#else
+static inline bool kasan_hw_tags_enabled(void)
+{
+	return false;
+}
+#endif /* CONFIG_KASAN_HW_TAGS */
+
+#endif /* LINUX_KASAN_ENABLED_H */