[PATCH] m68knommu : clear frame-pointer in start_thread

[Philippe De Muyter]

When trying to print the calltrace of a user process on m68knommu targets
gdb follows the frame-pointer and falls on unreachable adresses, because
the frame pointer is not properly initialised by start_thread. This patch
initialises the frame pointer to NULL in start_thread.

Signed-off-by: Philippe De Muyter <phdm@xxxxxxxxx>

---

the only real change is the initialisation of a6, the rest is spacing fixes
	((struct switch_stack *)(_regs))[-1].a6 = 0;

Index: linux-2.6.x/include/asm-m68knommu/processor.h
===================================================================
RCS file: /newdev6/cvsrepos/uClinux-dist/linux-2.6.x/include/asm-m68knommu/processor.h,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 processor.h
--- linux-2.6.x/include/asm-m68knommu/processor.h	2004/05/07 08:40:13	1.1.1.1
+++ linux-2.6.x/include/asm-m68knommu/processor.h	2006/03/16 07:26:52
@@ -89,14 +89,15 @@
  * pass the data segment into user programs if it exists,
  * it can't hurt anything as far as I can tell
  */
-#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;	\
+	if (current->mm)				\
+		(_regs)->d5 = current->mm->start_data;	\
+	(_regs)->sr &= ~0x2000;				\
+	wrusp(_usp);					\
 } while(0)
 
 /* Forward declaration, a strange C thing */
-
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