[PATCH] ppc32: discard *.exit.text and *.exit.data sections

Discard *.exit.text sections on runtime. We cannot do this on link time
because of the way BUG macros are implemented. If "__exit function" calls
one of those macros, __bug_table section will reference this function.
This is similar to ".altinstructions" situation on i386.

*.exit.data seems to be OK in this respect and is discarded on link
time.

Signed-off-by: Eugene Surovegin <[e-mail]>
Signed-off-by: Tom Rini <[e-mail]>
Acked-by: Paul Mackerras <[e-mail]>
Cc: Benjamin Herrenschmidt <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/ppc/kernel/vmlinux.lds.S

···
 	*(.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);
     __vtop_table_begin = .;
···
   /* Sections to be discarded. */
   /DISCARD/ : {
     *(.exitcall.exit)
+    *(.exit.data)
   }
 }