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>

arch/arm/mm/mmap.c

@@ -54,7 +54,8 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
 	 * We enforce the MAP_FIXED case.
 	 */
 	if (flags & MAP_FIXED) {
-		if (aliasing && flags & MAP_SHARED && addr & (SHMLBA - 1))
+		if (aliasing && flags & MAP_SHARED &&
+		    (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
 			return -EINVAL;
 		return addr;
 	}