[PATCH 4/6] arm: 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 M??ller <dl9pf at gmx.de>
---
 arch/arm/kernel/stacktrace.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c
index f065eb0..92b7237 100644
--- a/arch/arm/kernel/stacktrace.c
+++ b/arch/arm/kernel/stacktrace.c
@@ -134,12 +134,10 @@ static noinline void __save_stack_trace(struct task_struct *tsk,
 		frame.pc = thread_saved_pc(tsk);
 #endif
 	} else {
-		register unsigned long current_sp asm ("sp");
-
 		/* We don't want this function nor the caller */
 		data.skip += 2;
 		frame.fp = (unsigned long)__builtin_frame_address(0);
-		frame.sp = current_sp;
+		frame.sp = current_stack_pointer;
 		frame.lr = (unsigned long)__builtin_return_address(0);
 		frame.pc = (unsigned long)__save_stack_trace;
 	}
-- 
1.9.1