Messages in this thread | | | Date | Wed, 9 Aug 2023 18:16:19 +0800 | Subject | Re: [PATCH v6 3/4] iommufd: Add IOMMU_GET_HW_INFO | From | Baolu Lu <> |
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On 2023/8/8 23:35, Yi Liu wrote: > +static int iommufd_fill_hw_info(struct device *dev, void __user *user_ptr, > + unsigned int *length, u32 *type) > +{ > + const struct iommu_ops *ops; > + unsigned int data_len; > + void *data; > + int rc = 0; > + > + ops = dev_iommu_ops(dev); > + if (!ops->hw_info) { > + *length = 0; > + *type = IOMMU_HW_INFO_TYPE_NONE; > + return 0; > + } > + > + data = ops->hw_info(dev, &data_len, type); > + if (IS_ERR(data)) > + return PTR_ERR(data); > + > + /* > + * drivers that have hw_info callback should have a unique > + * iommu_hw_info_type. > + */ > + if (WARN_ON_ONCE(*type == IOMMU_HW_INFO_TYPE_NONE)) { > + rc = -ENODEV; > + goto err_free; > + } > + > + *length = min(*length, data_len); > + if (copy_to_user(user_ptr, data, *length)) {
copy_to_user() returns the number of bytes that were successfully copied, right?
If so, isn't it always failure case? Or I missed anything?
> + rc = -EFAULT; > + goto err_free;
nit: this goto is unnecessary.
> + } > + > +err_free: > + kfree(data); > + return rc; > +}
Best regards, baolu
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