[S390] Use generic bug.

Generic bug implementation for s390. Will increase the value of the
console output on BUG() statements since registers r0-r5,r14 will
not be clobbered by a printk() call that was previously done before
the illegal instruction of BUG() was hit.
Also implements an architecture specific WARN_ON(). Output of that
could be increased but requires common code change.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

arch/s390/kernel/vmlinux.lds.S

@@ -45,6 +45,8 @@ SECTIONS
   __ex_table : { *(__ex_table) }
   __stop___ex_table = .;
 
+  BUG_TABLE
+
   .data : {			/* Data */
 	*(.data)
 	CONSTRUCTORS
@@ -77,6 +79,12 @@ SECTIONS
 	*(.init.text)
 	_einittext = .;
   }
+  /*
+   * .exit.text is discarded at runtime, not link time,
+   * to deal with references from __bug_table
+   */
+  .exit.text :	 { *(.exit.text) }
+
   .init.data : { *(.init.data) }
   . = ALIGN(256);
   __setup_start = .;
@@ -116,7 +124,7 @@ SECTIONS
 
   /* Sections to be discarded */
   /DISCARD/ : {
-	*(.exit.text) *(.exit.data) *(.exitcall.exit)
+	*(.exit.data) *(.exitcall.exit)
 	}
 
   /* Stabs debugging sections.  */