-#define start_thread(_regs, _pc, _usp) \
-do { \
- set_fs(USER_DS); /* reads from user space */ \
- (_regs)->pc = (_pc); \
- if (current->mm) \
- (_regs)->d5 = current->mm->start_data; \
- (_regs)->sr &= ~0x2000; \
- wrusp(_usp); \
+#define start_thread(_regs, _pc, _usp) \
+do { \
+ set_fs(USER_DS); /* reads from user space */ \
+ (_regs)->pc = (_pc); \
+ ((struct switch_stack *)(_regs))[-1].a6 = 0; \
+ reformat(_regs); \
+ if (current->mm) \
+ (_regs)->d5 = current->mm->start_data; \
+ (_regs)->sr &= ~0x2000; \
+ wrusp(_usp); \