ftrace/fgraph/x86: Have prepare_ftrace_return() take ip as first parameter

The function graph helper function prepare_ftrace_return() which does the work
to hijack the parent pointer has that parent pointer as its first parameter.
Instead, if we make it the second parameter and have ip as the first parameter
(self_addr), then it can use the %rdi from save_mcount_regs that loads it
already.

Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 60881d919432..2142376dc8c6 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -871,7 +871,7 @@ static void *addr_from_call(void *ptr)
 	return ptr + MCOUNT_INSN_SIZE + calc.offset;
 }
 
-void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
+void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent,
 			   unsigned long frame_pointer);
 
 /*
@@ -964,7 +964,7 @@ int ftrace_disable_ftrace_graph_caller(void)
  * Hook the return address and push it in the stack of return addrs
  * in current thread info.
  */
-void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
+void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent,
 			   unsigned long frame_pointer)
 {
 	unsigned long old;