static int vfio_iommu_type1_get_info()

in vfio_iommu_type1.c [2740:2804]

• 48 lines of code
• 11 McCabe index (conditional complexity)

static int vfio_iommu_type1_get_info(struct vfio_iommu *iommu,
				     unsigned long arg)
{
	struct vfio_iommu_type1_info info;
	unsigned long minsz;
	struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
	unsigned long capsz;
	int ret;

	minsz = offsetofend(struct vfio_iommu_type1_info, iova_pgsizes);

	/* For backward compatibility, cannot require this */
	capsz = offsetofend(struct vfio_iommu_type1_info, cap_offset);

	if (copy_from_user(&info, (void __user *)arg, minsz))
		return -EFAULT;

	if (info.argsz < minsz)
		return -EINVAL;

	if (info.argsz >= capsz) {
		minsz = capsz;
		info.cap_offset = 0; /* output, no-recopy necessary */
	}

	mutex_lock(&iommu->lock);
	info.flags = VFIO_IOMMU_INFO_PGSIZES;

	info.iova_pgsizes = iommu->pgsize_bitmap;

	ret = vfio_iommu_migration_build_caps(iommu, &caps);

	if (!ret)
		ret = vfio_iommu_dma_avail_build_caps(iommu, &caps);

	if (!ret)
		ret = vfio_iommu_iova_build_caps(iommu, &caps);

	mutex_unlock(&iommu->lock);

	if (ret)
		return ret;

	if (caps.size) {
		info.flags |= VFIO_IOMMU_INFO_CAPS;

		if (info.argsz < sizeof(info) + caps.size) {
			info.argsz = sizeof(info) + caps.size;
		} else {
			vfio_info_cap_shift(&caps, sizeof(info));
			if (copy_to_user((void __user *)arg +
					sizeof(info), caps.buf,
					caps.size)) {
				kfree(caps.buf);
				return -EFAULT;
			}
			info.cap_offset = sizeof(info);
		}

		kfree(caps.buf);
	}

	return copy_to_user((void __user *)arg, &info, minsz) ?
			-EFAULT : 0;
}