diff options
Diffstat (limited to 'drivers/s390/cio/vfio_ccw_ops.c')
| -rw-r--r-- | drivers/s390/cio/vfio_ccw_ops.c | 28 |
1 files changed, 19 insertions, 9 deletions
diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c index 3fdcc6dfe0bf..025c8a832bc8 100644 --- a/drivers/s390/cio/vfio_ccw_ops.c +++ b/drivers/s390/cio/vfio_ccw_ops.c @@ -169,16 +169,20 @@ static ssize_t vfio_ccw_mdev_read(struct mdev_device *mdev, { struct vfio_ccw_private *private; struct ccw_io_region *region; + int ret; if (*ppos + count > sizeof(*region)) return -EINVAL; private = dev_get_drvdata(mdev_parent_dev(mdev)); + mutex_lock(&private->io_mutex); region = private->io_region; if (copy_to_user(buf, (void *)region + *ppos, count)) - return -EFAULT; - - return count; + ret = -EFAULT; + else + ret = count; + mutex_unlock(&private->io_mutex); + return ret; } static ssize_t vfio_ccw_mdev_write(struct mdev_device *mdev, @@ -188,23 +192,29 @@ static ssize_t vfio_ccw_mdev_write(struct mdev_device *mdev, { struct vfio_ccw_private *private; struct ccw_io_region *region; + int ret; if (*ppos + count > sizeof(*region)) return -EINVAL; private = dev_get_drvdata(mdev_parent_dev(mdev)); + if (!mutex_trylock(&private->io_mutex)) + return -EAGAIN; region = private->io_region; - if (copy_from_user((void *)region + *ppos, buf, count)) - return -EFAULT; + if (copy_from_user((void *)region + *ppos, buf, count)) { + ret = -EFAULT; + goto out_unlock; + } vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_IO_REQ); - if (region->ret_code != 0) { + if (region->ret_code != 0) private->state = VFIO_CCW_STATE_IDLE; - return region->ret_code; - } + ret = (region->ret_code != 0) ? region->ret_code : count; - return count; +out_unlock: + mutex_unlock(&private->io_mutex); + return ret; } static int vfio_ccw_mdev_get_device_info(struct vfio_device_info *info) |