[PATCH V2 6/6] arm64: LLVMLinux: Use global stack pointer in return_address()

[behanw@converseincode.com (behanw at converseincode.com)]

From: Behan Webster <behanw@converseincode.com>

The global register current_stack_pointer holds the current stack pointer.
This change supports being able to compile the kernel with both gcc and clang.

Author: Mark Charlebois <charlebm@gmail.com>
Signed-off-by: Mark Charlebois <charlebm@gmail.com>
Signed-off-by: Behan Webster <behanw@converseincode.com>
---
 arch/arm64/kernel/return_address.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/arm64/kernel/return_address.c b/arch/arm64/kernel/return_address.c
index 89102a6..6c4fd28 100644
--- a/arch/arm64/kernel/return_address.c
+++ b/arch/arm64/kernel/return_address.c
@@ -36,13 +36,12 @@ void *return_address(unsigned int level)
 {
 	struct return_address_data data;
 	struct stackframe frame;
-	register unsigned long current_sp asm ("sp");
 
 	data.level = level + 2;
 	data.addr = NULL;
 
 	frame.fp = (unsigned long)__builtin_frame_address(0);
-	frame.sp = current_sp;
+	frame.sp = current_stack_pointer;
 	frame.pc = (unsigned long)return_address; /* dummy */
 
 	walk_stackframe(&frame, save_return_addr, &data);
-- 
1.9.1