[PATCH V2 2/6] arm64: LLVMLinux: Use current_stack_pointer in save_stack_trace_tsk

[behanw at converseincode.com]

From: Behan Webster <behanw at converseincode.com>

Use the global current_stack_pointer to get the value of the stack pointer.
This change supports being able to compile the kernel with both gcc and clang.

Signed-off-by: Behan Webster <behanw at converseincode.com>
Signed-off-by: Mark Charlebois <charlebm at gmail.com>
Reviewed-by: Jan-Simon Möller <dl9pf at gmx.de>
Reviewed-by: Olof Johansson <olof at lixom.net>
Acked-by: Will Deacon <will.deacon at arm.com>
---
 arch/arm64/kernel/stacktrace.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
index 55437ba..407991b 100644
--- a/arch/arm64/kernel/stacktrace.c
+++ b/arch/arm64/kernel/stacktrace.c
@@ -111,10 +111,9 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
 		frame.sp = thread_saved_sp(tsk);
 		frame.pc = thread_saved_pc(tsk);
 	} else {
-		register unsigned long current_sp asm("sp");
 		data.no_sched_functions = 0;
 		frame.fp = (unsigned long)__builtin_frame_address(0);
-		frame.sp = current_sp;
+		frame.sp = current_stack_pointer;
 		frame.pc = (unsigned long)save_stack_trace_tsk;
 	}
 
-- 
1.9.1