1 files changed, 65 insertions, 2 deletions

diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 7363ccf79512..0cbe38a844fa 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -119,7 +119,7 @@ print_graph_duration(struct trace_array *tr, unsigned long long duration,
 /* Add a function return address to the trace stack on thread info.*/
 int
 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
-			 unsigned long frame_pointer)
+			 unsigned long frame_pointer, unsigned long *retp)
 {
 	unsigned long long calltime;
 	int index;
@@ -171,7 +171,12 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
 	current->ret_stack[index].func = func;
 	current->ret_stack[index].calltime = calltime;
 	current->ret_stack[index].subtime = 0;
+#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
 	current->ret_stack[index].fp = frame_pointer;
+#endif
+#ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
+	current->ret_stack[index].retp = retp;
+#endif
 	*depth = current->curr_ret_stack;
 
 	return 0;
@@ -204,7 +209,7 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret,
 		return;
 	}
 
-#if defined(CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST) && !defined(CC_USING_FENTRY)
+#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
 	/*
 	 * The arch may choose to record the frame pointer used
 	 * and check it here to make sure that it is what we expect it
@@ -279,6 +284,64 @@ unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
 	return ret;
 }
 
+/**
+ * ftrace_graph_ret_addr - convert a potentially modified stack return address
+ *			   to its original value
+ *
+ * This function can be called by stack unwinding code to convert a found stack
+ * return address ('ret') to its original value, in case the function graph
+ * tracer has modified it to be 'return_to_handler'.  If the address hasn't
+ * been modified, the unchanged value of 'ret' is returned.
+ *
+ * 'idx' is a state variable which should be initialized by the caller to zero
+ * before the first call.
+ *
+ * 'retp' is a pointer to the return address on the stack.  It's ignored if
+ * the arch doesn't have HAVE_FUNCTION_GRAPH_RET_ADDR_PTR defined.
+ */
+#ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
+unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
+				    unsigned long ret, unsigned long *retp)
+{
+	int index = task->curr_ret_stack;
+	int i;
+
+	if (ret != (unsigned long)return_to_handler)
+		return ret;
+
+	if (index < -1)
+		index += FTRACE_NOTRACE_DEPTH;
+
+	if (index < 0)
+		return ret;
+
+	for (i = 0; i <= index; i++)
+		if (task->ret_stack[i].retp == retp)
+			return task->ret_stack[i].ret;
+
+	return ret;
+}
+#else /* !HAVE_FUNCTION_GRAPH_RET_ADDR_PTR */
+unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
+				    unsigned long ret, unsigned long *retp)
+{
+	int task_idx;
+
+	if (ret != (unsigned long)return_to_handler)
+		return ret;
+
+	task_idx = task->curr_ret_stack;
+
+	if (!task->ret_stack || task_idx < *idx)
+		return ret;
+
+	task_idx -= *idx;
+	(*idx)++;
+
+	return task->ret_stack[task_idx].ret;
+}
+#endif /* HAVE_FUNCTION_GRAPH_RET_ADDR_PTR */
+
 int __trace_graph_entry(struct trace_array *tr,
 				struct ftrace_graph_ent *trace,
 				unsigned long flags,