[PATCH v2 06/13] powerpc/ftrace: Simplify PPC32's return_to_handler()

From: Christophe Leroy
Date: Mon Dec 20 2021 - 11:38:28 EST


return_to_handler() was copied from PPC64. For PPC32 it
just needs to save r3 and r4, and doesn't require any nop
after the bl.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
arch/powerpc/kernel/trace/ftrace_32.S | 16 ++++++----------
1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/kernel/trace/ftrace_32.S b/arch/powerpc/kernel/trace/ftrace_32.S
index 7e2fd729116b..95ffea2bdc29 100644
--- a/arch/powerpc/kernel/trace/ftrace_32.S
+++ b/arch/powerpc/kernel/trace/ftrace_32.S
@@ -162,22 +162,18 @@ _GLOBAL(ftrace_graph_caller)

_GLOBAL(return_to_handler)
/* need to save return values */
- stwu r1, -32(r1)
- stw r3, 20(r1)
- stw r4, 16(r1)
- stw r31, 12(r1)
- mr r31, r1
+ stwu r1, -16(r1)
+ stw r3, 8(r1)
+ stw r4, 12(r1)

bl ftrace_return_to_handler
- nop

/* return value has real return address */
mtlr r3

- lwz r3, 20(r1)
- lwz r4, 16(r1)
- lwz r31,12(r1)
- lwz r1, 0(r1)
+ lwz r3, 8(r1)
+ lwz r4, 12(r1)
+ addi r1, r1, 16

/* Jump back to real return address */
blr
--
2.33.1