compat_ioctl: block: move blkdev_compat_ioctl() into ioctl.c

Having both in the same file allows a number of simplifications
to the compat path, and makes it more likely that changes to
the native path get applied to the compat version as well.

Reviewed-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 219 insertions, 0 deletions

diff --git a/block/ioctl.c b/block/ioctl.c
index e728331d1a5b..f8c4e2649335 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -269,6 +269,38 @@ static int put_u64(unsigned long arg, u64 val)
 	return put_user(val, (u64 __user *)arg);
 }
 
+#ifdef CONFIG_COMPAT
+static int compat_put_ushort(unsigned long arg, unsigned short val)
+{
+	return put_user(val, (unsigned short __user *)compat_ptr(arg));
+}
+
+static int compat_put_int(unsigned long arg, int val)
+{
+	return put_user(val, (compat_int_t __user *)compat_ptr(arg));
+}
+
+static int compat_put_uint(unsigned long arg, unsigned int val)
+{
+	return put_user(val, (compat_uint_t __user *)compat_ptr(arg));
+}
+
+static int compat_put_long(unsigned long arg, long val)
+{
+	return put_user(val, (compat_long_t __user *)compat_ptr(arg));
+}
+
+static int compat_put_ulong(unsigned long arg, compat_ulong_t val)
+{
+	return put_user(val, (compat_ulong_t __user *)compat_ptr(arg));
+}
+
+static int compat_put_u64(unsigned long arg, u64 val)
+{
+	return put_user(val, (compat_u64 __user *)compat_ptr(arg));
+}
+#endif
+
 int __blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
 			unsigned cmd, unsigned long arg)
 {
@@ -476,6 +508,44 @@ static int blkdev_getgeo(struct block_device *bdev,
 	return 0;
 }
 
+#ifdef CONFIG_COMPAT
+struct compat_hd_geometry {
+	unsigned char heads;
+	unsigned char sectors;
+	unsigned short cylinders;
+	u32 start;
+};
+
+static int compat_hdio_getgeo(struct gendisk *disk, struct block_device *bdev,
+			struct compat_hd_geometry __user *ugeo)
+{
+	struct hd_geometry geo;
+	int ret;
+
+	if (!ugeo)
+		return -EINVAL;
+	if (!disk->fops->getgeo)
+		return -ENOTTY;
+
+	memset(&geo, 0, sizeof(geo));
+	/*
+	 * We need to set the startsect first, the driver may
+	 * want to override it.
+	 */
+	geo.start = get_start_sect(bdev);
+	ret = disk->fops->getgeo(bdev, &geo);
+	if (ret)
+		return ret;
+
+	ret = copy_to_user(ugeo, &geo, 4);
+	ret |= put_user(geo.start, &ugeo->start);
+	if (ret)
+		ret = -EFAULT;
+
+	return ret;
+}
+#endif
+
 /* set the logical block size */
 static int blkdev_bszset(struct block_device *bdev, fmode_t mode,
 		int __user *argp)
@@ -604,3 +674,152 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
 	}
 }
 EXPORT_SYMBOL_GPL(blkdev_ioctl);
+
+#ifdef CONFIG_COMPAT
+struct compat_blkpg_ioctl_arg {
+	compat_int_t op;
+	compat_int_t flags;
+	compat_int_t datalen;
+	compat_caddr_t data;
+};
+
+static int compat_blkpg_ioctl(struct block_device *bdev, fmode_t mode,
+		unsigned int cmd, struct compat_blkpg_ioctl_arg __user *ua32)
+{
+	struct blkpg_ioctl_arg __user *a = compat_alloc_user_space(sizeof(*a));
+	compat_caddr_t udata;
+	compat_int_t n;
+	int err;
+
+	err = get_user(n, &ua32->op);
+	err |= put_user(n, &a->op);
+	err |= get_user(n, &ua32->flags);
+	err |= put_user(n, &a->flags);
+	err |= get_user(n, &ua32->datalen);
+	err |= put_user(n, &a->datalen);
+	err |= get_user(udata, &ua32->data);
+	err |= put_user(compat_ptr(udata), &a->data);
+	if (err)
+		return err;
+
+	return blkdev_ioctl(bdev, mode, cmd, (unsigned long)a);
+}
+
+#define BLKBSZGET_32		_IOR(0x12, 112, int)
+#define BLKBSZSET_32		_IOW(0x12, 113, int)
+#define BLKGETSIZE64_32		_IOR(0x12, 114, int)
+
+/* Most of the generic ioctls are handled in the normal fallback path.
+   This assumes the blkdev's low level compat_ioctl always returns
+   ENOIOCTLCMD for unknown ioctls. */
+long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
+{
+	int ret = -ENOIOCTLCMD;
+	struct inode *inode = file->f_mapping->host;
+	struct block_device *bdev = inode->i_bdev;
+	struct gendisk *disk = bdev->bd_disk;
+	fmode_t mode = file->f_mode;
+	loff_t size;
+	unsigned int max_sectors;
+
+	/*
+	 * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have
+	 * to updated it before every ioctl.
+	 */
+	if (file->f_flags & O_NDELAY)
+		mode |= FMODE_NDELAY;
+	else
+		mode &= ~FMODE_NDELAY;
+
+	switch (cmd) {
+	case HDIO_GETGEO:
+		return compat_hdio_getgeo(disk, bdev, compat_ptr(arg));
+	case BLKPBSZGET:
+		return compat_put_uint(arg, bdev_physical_block_size(bdev));
+	case BLKIOMIN:
+		return compat_put_uint(arg, bdev_io_min(bdev));
+	case BLKIOOPT:
+		return compat_put_uint(arg, bdev_io_opt(bdev));
+	case BLKALIGNOFF:
+		return compat_put_int(arg, bdev_alignment_offset(bdev));
+	case BLKDISCARDZEROES:
+		return compat_put_uint(arg, 0);
+	case BLKFLSBUF:
+	case BLKROSET:
+	case BLKDISCARD:
+	case BLKSECDISCARD:
+	case BLKZEROOUT:
+	/*
+	 * the ones below are implemented in blkdev_locked_ioctl,
+	 * but we call blkdev_ioctl, which gets the lock for us
+	 */
+	case BLKRRPART:
+	case BLKREPORTZONE:
+	case BLKRESETZONE:
+	case BLKOPENZONE:
+	case BLKCLOSEZONE:
+	case BLKFINISHZONE:
+	case BLKGETZONESZ:
+	case BLKGETNRZONES:
+		return blkdev_ioctl(bdev, mode, cmd,
+				(unsigned long)compat_ptr(arg));
+	case BLKBSZSET_32:
+		return blkdev_ioctl(bdev, mode, BLKBSZSET,
+				(unsigned long)compat_ptr(arg));
+	case BLKPG:
+		return compat_blkpg_ioctl(bdev, mode, cmd, compat_ptr(arg));
+	case BLKRAGET:
+	case BLKFRAGET:
+		if (!arg)
+			return -EINVAL;
+		return compat_put_long(arg,
+			       (bdev->bd_bdi->ra_pages * PAGE_SIZE) / 512);
+	case BLKROGET: /* compatible */
+		return compat_put_int(arg, bdev_read_only(bdev) != 0);
+	case BLKBSZGET_32: /* get the logical block size (cf. BLKSSZGET) */
+		return compat_put_int(arg, block_size(bdev));
+	case BLKSSZGET: /* get block device hardware sector size */
+		return compat_put_int(arg, bdev_logical_block_size(bdev));
+	case BLKSECTGET:
+		max_sectors = min_t(unsigned int, USHRT_MAX,
+				    queue_max_sectors(bdev_get_queue(bdev)));
+		return compat_put_ushort(arg, max_sectors);
+	case BLKROTATIONAL:
+		return compat_put_ushort(arg,
+					 !blk_queue_nonrot(bdev_get_queue(bdev)));
+	case BLKRASET: /* compatible, but no compat_ptr (!) */
+	case BLKFRASET:
+		if (!capable(CAP_SYS_ADMIN))
+			return -EACCES;
+		bdev->bd_bdi->ra_pages = (arg * 512) / PAGE_SIZE;
+		return 0;
+	case BLKGETSIZE:
+		size = i_size_read(bdev->bd_inode);
+		if ((size >> 9) > ~0UL)
+			return -EFBIG;
+		return compat_put_ulong(arg, size >> 9);
+
+	case BLKGETSIZE64_32:
+		return compat_put_u64(arg, i_size_read(bdev->bd_inode));
+
+	case BLKTRACESETUP32:
+	case BLKTRACESTART: /* compatible */
+	case BLKTRACESTOP:  /* compatible */
+	case BLKTRACETEARDOWN: /* compatible */
+		ret = blk_trace_ioctl(bdev, cmd, compat_ptr(arg));
+		return ret;
+	case IOC_PR_REGISTER:
+	case IOC_PR_RESERVE:
+	case IOC_PR_RELEASE:
+	case IOC_PR_PREEMPT:
+	case IOC_PR_PREEMPT_ABORT:
+	case IOC_PR_CLEAR:
+		return blkdev_ioctl(bdev, mode, cmd,
+				(unsigned long)compat_ptr(arg));
+	default:
+		if (disk->fops->compat_ioctl)
+			ret = disk->fops->compat_ioctl(bdev, mode, cmd, arg);
+		return ret;
+	}
+}
+#endif