fix broken aliasing checks for MAP_FIXED on sparc32, mips, arm and sh

We want addr - (pgoff << PAGE_SHIFT) consistently coloured...

Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/mips/kernel/syscall.c b/arch/mips/kernel/syscall.c
index c25b2e7d..3f7f466 100644
--- a/arch/mips/kernel/syscall.c
+++ b/arch/mips/kernel/syscall.c
@@ -93,7 +93,8 @@
 		 * We do not accept a shared mapping if it would violate
 		 * cache aliasing constraints.
 		 */
-		if ((flags & MAP_SHARED) && (addr & shm_align_mask))
+		if ((flags & MAP_SHARED) &&
+		    ((addr - (pgoff << PAGE_SHIFT)) & shm_align_mask))
 			return -EINVAL;
 		return addr;
 	}