m68k: sanitize copy_thread(), fork/vfork/clone wrappers, switch to generic fork/vfork

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/m68k/kernel/entry.S b/arch/m68k/kernel/entry.S
index 45b2f29..a78f564 100644
--- a/arch/m68k/kernel/entry.S
+++ b/arch/m68k/kernel/entry.S
@@ -44,34 +44,29 @@
 
 .globl system_call, buserr, trap, resume
 .globl sys_call_table
-.globl sys_fork, sys_clone, sys_vfork
+.globl __sys_fork, __sys_clone, __sys_vfork
 .globl ret_from_interrupt, bad_interrupt
 .globl auto_irqhandler_fixup
 .globl user_irqvec_fixup
 
 .text
-ENTRY(sys_fork)
+ENTRY(__sys_fork)
 	SAVE_SWITCH_STACK
-	pea	%sp@(SWITCH_STACK_SIZE)
-	jbsr	m68k_fork
-	addql	#4,%sp
-	RESTORE_SWITCH_STACK
+	jbsr	sys_fork
+	lea     %sp@(24),%sp
 	rts
 
-ENTRY(sys_clone)
+ENTRY(__sys_clone)
 	SAVE_SWITCH_STACK
 	pea	%sp@(SWITCH_STACK_SIZE)
 	jbsr	m68k_clone
-	addql	#4,%sp
-	RESTORE_SWITCH_STACK
+	lea     %sp@(28),%sp
 	rts
 
-ENTRY(sys_vfork)
+ENTRY(__sys_vfork)
 	SAVE_SWITCH_STACK
-	pea	%sp@(SWITCH_STACK_SIZE)
-	jbsr	m68k_vfork
-	addql	#4,%sp
-	RESTORE_SWITCH_STACK
+	jbsr	sys_vfork
+	lea     %sp@(24),%sp
 	rts
 
 ENTRY(sys_sigreturn)