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

The function_graph_entry() 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 powerpc 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: Benjamin Herrenschmidt <b...@kernel.crashing.org>
Cc: Paul Mackerras <pau...@samba.org>
Cc: Michael Ellerman <m...@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: sta...@kernel.org
Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace 
return callback")
Signed-off-by: Steven Rostedt (VMware) <rost...@goodmis.org>
---
 arch/powerpc/kernel/trace/ftrace.c | 15 ++-------------
 1 file changed, 2 insertions(+), 13 deletions(-)

diff --git a/arch/powerpc/kernel/trace/ftrace.c 
b/arch/powerpc/kernel/trace/ftrace.c
index 4bf051d3e21e..b65c8a34ad6e 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -950,7 +950,6 @@ int ftrace_disable_ftrace_graph_caller(void)
  */
 unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip)
 {
-       struct ftrace_graph_ent trace;
        unsigned long return_hooker;
 
        if (unlikely(ftrace_graph_is_dead()))
@@ -961,18 +960,8 @@ unsigned long prepare_ftrace_return(unsigned long parent, 
unsigned long ip)
 
        return_hooker = ppc_function_entry(return_to_handler);
 
-       trace.func = ip;
-       trace.depth = current->curr_ret_stack + 1;
-
-       /* Only trace if the calling function expects to */
-       if (!ftrace_graph_entry(&trace))
-               goto out;
-
-       if (ftrace_push_return_trace(parent, ip, &trace.depth, 0,
-                                    NULL) == -EBUSY)
-               goto out;
-
-       parent = return_hooker;
+       if (!function_graph_enter(parent, ip, 0, NULL))
+               parent = return_hooker;
 out:
        return parent;
 }
-- 
2.19.1


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