1 files changed, 34 insertions, 0 deletions
diff --git a/runtime/current.c b/runtime/current.c
new file mode 100644
index 00000000..78820c40
--- /dev/null
+++ b/runtime/current.c
@@ -0,0 +1,34 @@
+#ifndef _CURRENT_C_
+#define _CURRENT_C_
+
+/* -*- linux-c -*- */
+/** @file current.c
+ * @brief Functions to get the current state.
+ */
+/** @addtogroup current Current State
+ * Functions to get the current state.
+ * @{
+ */
+
+
+/** Get the current return address.
+ * Call from kprobes (not jprobes).
+ * @param regs The pt_regs saved by the kprobe.
+ * @return The return address saved in esp or rsp.
+ * @note i386 and x86_64 only so far.
+ */
+ 
+unsigned long _stp_ret_addr (struct pt_regs *regs)
+{
+#ifdef __x86_64__
+  unsigned long *ra = (unsigned long *)regs->rsp;
+#else
+  unsigned long *ra = (unsigned long *)regs->esp;
+#endif
+  if (ra)
+    return *ra;
+  else
+    return 0;
+}
+/** @} */
+#endif /* _CURRENT_C_ */