--- zzzz-none-000/linux-2.6.32.61/arch/mips/include/asm/processor.h	2013-06-10 09:43:48.000000000 +0000
+++ ar9-7330-650/linux-2.6.32.61/arch/mips/include/asm/processor.h	2011-03-11 14:47:38.000000000 +0000
@@ -316,6 +316,7 @@
 #define task_pt_regs(tsk) ((struct pt_regs *)__KSTK_TOS(tsk))
 #define KSTK_EIP(tsk) (task_pt_regs(tsk)->cp0_epc)
 #define KSTK_ESP(tsk) (task_pt_regs(tsk)->regs[29])
+#define KSTK_RA(tsk) (task_pt_regs(tsk)->regs[31])
 #define KSTK_STATUS(tsk) (task_pt_regs(tsk)->cp0_status)
 
 #define cpu_relax()	barrier()