decompress: fix new decompressor for PIC

The ARM kernel decompressor wants to be able to relocate r/w data
independently from the rest of the image, and we do this by ensuring that
r/w data has global visibility.  Define STATIC_RW_DATA to be empty to
achieve this.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Alain Knaff <alain@knaff.lu>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/decompress/mm.h

@@ -14,11 +14,21 @@
 
 /* Code active when included from pre-boot environment: */
 
+/*
+ * Some architectures want to ensure there is no local data in their
+ * pre-boot environment, so that data can arbitarily relocated (via
+ * GOT references).  This is achieved by defining STATIC_RW_DATA to
+ * be null.
+ */
+#ifndef STATIC_RW_DATA
+#define STATIC_RW_DATA static
+#endif
+
 /* A trivial malloc implementation, adapted from
  *  malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994
  */
-static unsigned long malloc_ptr;
-static int malloc_count;
+STATIC_RW_DATA unsigned long malloc_ptr;
+STATIC_RW_DATA int malloc_count;
 
 static void *malloc(int size)
 {