frv: fix mmap2 error handling

Fix the error handling in sys_mmap2().  Currently, if the pgoff check
fails, fput() might have to be called (which it isn't), so do the pgoff
check first, before fget() is called.

Signed-off-by: David Howells <dhowells@redhat.com>
Reported-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/frv/kernel/sys_frv.c

@@ -35,13 +35,6 @@ asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
 	int error = -EBADF;
 	struct file * file = NULL;
 
-	flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
-	if (!(flags & MAP_ANONYMOUS)) {
-		file = fget(fd);
-		if (!file)
-			goto out;
-	}
-
 	/* As with sparc32, make sure the shift for mmap2 is constant
 	   (12), no matter what PAGE_SIZE we have.... */
 
@@ -49,8 +42,14 @@ asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
 	   trying to map something we can't */
 	if (pgoff & ((1 << (PAGE_SHIFT - 12)) - 1))
 		return -EINVAL;
+	pgoff >>= PAGE_SHIFT - 12;
 
-	pgoff >>= (PAGE_SHIFT - 12);
+	flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
+	if (!(flags & MAP_ANONYMOUS)) {
+		file = fget(fd);
+		if (!file)
+			goto out;
+	}
 
 	down_write(&current->mm->mmap_sem);
 	error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);