1 files changed, 28 insertions, 0 deletions
diff --git a/accel/tcg/user-retaddr.h b/accel/tcg/user-retaddr.h
new file mode 100644
index 0000000..e0f57e1
--- /dev/null
+++ b/accel/tcg/user-retaddr.h
@@ -0,0 +1,28 @@
+#ifndef ACCEL_TCG_USER_RETADDR_H
+#define ACCEL_TCG_USER_RETADDR_H
+
+#include "qemu/atomic.h"
+
+extern __thread uintptr_t helper_retaddr;
+
+static inline void set_helper_retaddr(uintptr_t ra)
+{
+    helper_retaddr = ra;
+    /*
+     * Ensure that this write is visible to the SIGSEGV handler that
+     * may be invoked due to a subsequent invalid memory operation.
+     */
+    signal_barrier();
+}
+
+static inline void clear_helper_retaddr(void)
+{
+    /*
+     * Ensure that previous memory operations have succeeded before
+     * removing the data visible to the signal handler.
+     */
+    signal_barrier();
+    helper_retaddr = 0;
+}
+
+#endif