[PATCH] Fix RELOC_HIDE miscompilation

RELOC_HIDE got miscompiled on gcc3.1/x86-64 in the access to softirq.c's per
cpu variables.  This fixes the problem.

Clearly to hide the relocation the addition needs to be done after the
value obfuscation, not before.

I don't know if it triggers on other architectures (x86-64 is especially
stressf here because it has negative kernel addresses), but seems like the
right thing to do.

include/linux/compiler.h

@@ -16,7 +16,7 @@
 /* This macro obfuscates arithmetic on a variable address so that gcc
    shouldn't recognize the original var, and make assumptions about it */
 #define RELOC_HIDE(ptr, off)					\
-  ({ __typeof__(ptr) __ptr;					\
-    __asm__ ("" : "=g"(__ptr) : "0"((void *)(ptr) + (off)));	\
-    __ptr; })
+  ({ unsigned long __ptr;					\
+    __asm__ ("" : "=g"(__ptr) : "0"(ptr));		\
+    (typeof(ptr)) (__ptr + (off)); })
 #endif /* __LINUX_COMPILER_H */