[PATCH v2 01/25] powerpc/ftrace: Refactor prepare_ftrace_return()

From: Christophe Leroy
Date: Sat May 07 2022 - 02:48:58 EST


When we have CONFIG_DYNAMIC_FTRACE_WITH_ARGS,
prepare_ftrace_return() is called by ftrace_graph_func()
otherwise prepare_ftrace_return() is called from assembly.

Refactor prepare_ftrace_return() into a static
__prepare_ftrace_return() that will be called by both
prepare_ftrace_return() and ftrace_graph_func().

It will allow GCC to fold __prepare_ftrace_return() inside
ftrace_graph_func().

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
arch/powerpc/kernel/trace/ftrace.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index 4ee04aacf9f1..7a266fd469b7 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -939,8 +939,8 @@ int ftrace_disable_ftrace_graph_caller(void)
* Hook the return address and push it in the stack of return addrs
* in current thread info. Return the address we want to divert to.
*/
-unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip,
- unsigned long sp)
+static unsigned long
+__prepare_ftrace_return(unsigned long parent, unsigned long ip, unsigned long sp)
{
unsigned long return_hooker;
int bit;
@@ -969,7 +969,13 @@ unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip,
void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct ftrace_regs *fregs)
{
- fregs->regs.link = prepare_ftrace_return(parent_ip, ip, fregs->regs.gpr[1]);
+ fregs->regs.link = __prepare_ftrace_return(parent_ip, ip, fregs->regs.gpr[1]);
+}
+#else
+unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip,
+ unsigned long sp)
+{
+ return __prepare_ftrace_return(parent, ip, sp);
}
#endif
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
--
2.35.1