[PATCH 4.19 105/139] sparc/function_graph: Simplify with function_graph_enter()

[Greg Kroah-Hartman]

4.19-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Steven Rostedt (VMware) <rost...@goodmis.org>

commit 9c4bf5e0db164f330a2d3e128e9832661f69f0e9 upstream.

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.

Cc: "David S. Miller" <da...@davemloft.net>
Cc: sparcli...@vger.kernel.org
Cc: sta...@kernel.org
Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace 
return callback")
Reviewed-by: Masami Hiramatsu <mhira...@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rost...@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 arch/sparc/kernel/ftrace.c |   11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

--- a/arch/sparc/kernel/ftrace.c
+++ b/arch/sparc/kernel/ftrace.c
@@ -126,20 +126,11 @@ unsigned long prepare_ftrace_return(unsi
                                    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;