FAILED: patch "[PATCH] sparc/function_graph: Simplify with function_graph_enter()" failed to apply to 4.4-stable tree

The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From: "Steven Rostedt (VMware)" <[email protected]>
Date: Sun, 18 Nov 2018 17:37:40 -0500
Subject: [PATCH] sparc/function_graph: Simplify with function_graph_enter()

The function_graph_enter() function does the work of calling the function graph hook function and the management of the shadow stack, simplifying the work done in the architecture dependent prepare_ftrace_return().

Have sparc use the new code, and remove the shadow stack management as well as having to set up the trace structure.

This is needed to prepare for a fix of a design bug on how the curr_ret_stack is used.

index 915dda4ae412..684b84ce397f 100644
@@ -126,20 +126,11 @@ unsigned long prepare_ftrace_return(unsigned long parent,
 				    unsigned long frame_pointer)
 {
 	unsigned long return_hooker = (unsigned long) &return_to_handler;
-	struct ftrace_graph_ent trace;
 
 	if (unlikely(atomic_read(&current->tracing_graph_pause)))
 		return parent + 8UL;
 
-	trace.func = self_addr;
-	trace.depth = current->curr_ret_stack + 1;
-
-	/* Only trace if the calling function expects to */
-	if (!ftrace_graph_entry(&trace))
-		return parent + 8UL;
-
-	if (ftrace_push_return_trace(parent, self_addr, &trace.depth,
-				     frame_pointer, NULL) == -EBUSY)
+	if (function_graph_enter(parent, self_addr, frame_pointer, NULL))
 		return parent + 8UL;
 
 	return return_hooker;