init: disable sparse checking of the mount.o source files

The init/mount.o source files produce a number of sparse warnings of the
type:

warning: incorrect type in argument 1 (different address spaces)
expected char [noderef] <asn:1>*dev_name
got char *name

This is due to the syscalls expecting some of the arguments to be user
pointers but they are being passed as kernel pointers. This is harmless
but adds a lot of noise to a sparse build.

To limit the noise just disable the sparse checking in the relevant source
files, but still display a warning so that the user knows this has been
done.

Since the sparse checking has been disabled we can also remove the __user
__force casts that are scattered thru the source.

Signed-off-by: H Hartley Sweeten <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

init/do_mounts.c

···
+/*
+ * Many of the syscalls used in this file expect some of the arguments
+ * to be __user pointers not __kernel pointers.  To limit the sparse
+ * noise, turn off sparse checking for this file.
+ */
+#ifdef __CHECKER__
+#undef __CHECKER__
+#warning "Sparse checking disabled for this file"
+#endif
+
 #include <linux/module.h>
 #include <linux/sched.h>
 #include <linux/ctype.h>
···
 	if (err)
 		return err;
 
-	sys_chdir((const char __user __force *)"/root");
+	sys_chdir("/root");
 	s = current->fs->pwd.dentry->d_sb;
 	ROOT_DEV = s->s_dev;
 	printk(KERN_INFO
···
 out:
 	devtmpfs_mount("dev");
 	sys_mount(".", "/", NULL, MS_MOVE, NULL);
-	sys_chroot((const char __user __force *)".");
+	sys_chroot(".");
 }

init/do_mounts_initrd.c

···
+/*
+ * Many of the syscalls used in this file expect some of the arguments
+ * to be __user pointers not __kernel pointers.  To limit the sparse
+ * noise, turn off sparse checking for this file.
+ */
+#ifdef __CHECKER__
+#undef __CHECKER__
+#warning "Sparse checking disabled for this file"
+#endif
+
 #include <linux/unistd.h>
 #include <linux/kernel.h>
 #include <linux/fs.h>

init/do_mounts_md.c

···
+/*
+ * Many of the syscalls used in this file expect some of the arguments
+ * to be __user pointers not __kernel pointers.  To limit the sparse
+ * noise, turn off sparse checking for this file.
+ */
+#ifdef __CHECKER__
+#undef __CHECKER__
+#warning "Sparse checking disabled for this file"
+#endif
+
 #include <linux/delay.h>
 #include <linux/raid/md_u.h>
 #include <linux/raid/md_p.h>
···
 
 	wait_for_device_probe();
 
-	fd = sys_open((const char __user __force *) "/dev/md0", 0, 0);
+	fd = sys_open("/dev/md0", 0, 0);
 	if (fd >= 0) {
 		sys_ioctl(fd, RAID_AUTORUN, raid_autopart);
 		sys_close(fd);

init/do_mounts_rd.c

···
+/*
+ * Many of the syscalls used in this file expect some of the arguments
+ * to be __user pointers not __kernel pointers.  To limit the sparse
+ * noise, turn off sparse checking for this file.
+ */
+#ifdef __CHECKER__
+#undef __CHECKER__
+#warning "Sparse checking disabled for this file"
+#endif
 
 #include <linux/kernel.h>
 #include <linux/fs.h>
···
 	char rotator[4] = { '|' , '/' , '-' , '\\' };
 #endif
 
-	out_fd = sys_open((const char __user __force *) "/dev/ram", O_RDWR, 0);
+	out_fd = sys_open("/dev/ram", O_RDWR, 0);
 	if (out_fd < 0)
 		goto out;
 
···
 	sys_close(out_fd);
 out:
 	kfree(buf);
-	sys_unlink((const char __user __force *) "/dev/ram");
+	sys_unlink("/dev/ram");
 	return res;
 }
 

init/initramfs.c

···
+/*
+ * Many of the syscalls used in this file expect some of the arguments
+ * to be __user pointers not __kernel pointers.  To limit the sparse
+ * noise, turn off sparse checking for this file.
+ */
+#ifdef __CHECKER__
+#undef __CHECKER__
+#warning "Sparse checking disabled for this file"
+#endif
+
 #include <linux/init.h>
 #include <linux/fs.h>
 #include <linux/slab.h>
···
 	}
 }
 
-static long __init do_utime(char __user *filename, time_t mtime)
+static long __init do_utime(char *filename, time_t mtime)
 {
 	struct timespec t[2];
 
···
 	struct linux_dirent64 *dirp;
 	int num;
 
-	fd = sys_open((const char __user __force *) "/", O_RDONLY, 0);
+	fd = sys_open("/", O_RDONLY, 0);
 	WARN_ON(fd < 0);
 	if (fd < 0)
 		return;
···
 		}
 		printk(KERN_INFO "rootfs image is not initramfs (%s)"
 				"; looks like an initrd\n", err);
-		fd = sys_open((const char __user __force *) "/initrd.image",
+		fd = sys_open("/initrd.image",
 			      O_WRONLY|O_CREAT, 0700);
 		if (fd >= 0) {
 			sys_write(fd, (char *)initrd_start,