[PATCH 1/6] arm: LLVMLinux: Add global named register current_stack_pointer for ARM

From: behanw
Date: Tue Jul 08 2014 - 16:16:44 EST


From: Behan Webster <behanw@xxxxxxxxxxxxxxxxxx>

Define a global named register for current_stack_pointer. The use of this new
variable guarantees that both gcc and clang can access this register in C code.

Signed-off-by: Behan Webster <behanw@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Jan-Simon MÃller <dl9pf@xxxxxx>
Reviewed-by: Mark Charlebois <charlebm@xxxxxxxxx>
---
arch/arm/include/asm/thread_info.h | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h
index e4e4208..9cb9c66 100644
--- a/arch/arm/include/asm/thread_info.h
+++ b/arch/arm/include/asm/thread_info.h
@@ -100,6 +100,11 @@ struct thread_info {
#define init_stack (init_thread_union.stack)

/*
+ * how to get the current stack pointer in C
+ */
+register unsigned long current_stack_pointer asm ("sp");
+
+/*
* how to get the thread information struct from C
*/
static inline struct thread_info *current_thread_info(void) __attribute_const__;
--
1.9.1

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