From: Nicolin Chen <[email protected]> Wrap up the data type/pointer/len sanity and a copy_struct_from_user call for iommu drivers to copy driver specific data via struct iommu_user_data. And expect it to be used in the domain_alloc_user op for example.
Signed-off-by: Nicolin Chen <[email protected]> Co-developed-by: Yi Liu <[email protected]> Signed-off-by: Yi Liu <[email protected]> Reviewed-by: Kevin Tian <[email protected]> Reviewed-by: Jason Gunthorpe <[email protected]> Signed-off-by: Jason Gunthorpe <[email protected]> --- include/linux/iommu.h | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 2ddd99f55471..8fb1b41b4d15 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -280,6 +280,46 @@ struct iommu_user_data { size_t len; }; +/** + * __iommu_copy_struct_from_user - Copy iommu driver specific user space data + * @dst_data: Pointer to an iommu driver specific user data that is defined in + * include/uapi/linux/iommufd.h + * @src_data: Pointer to a struct iommu_user_data for user space data info + * @data_type: The data type of the @dst_data. Must match with @src_data.type + * @data_len: Length of current user data structure, i.e. sizeof(struct _dst) + * @min_len: Initial length of user data structure for backward compatibility. + * This should be offsetofend using the last member in the user data + * struct that was initially added to include/uapi/linux/iommufd.h + */ +static inline int __iommu_copy_struct_from_user( + void *dst_data, const struct iommu_user_data *src_data, + unsigned int data_type, size_t data_len, size_t min_len) +{ + if (src_data->type != data_type) + return -EINVAL; + if (WARN_ON(!dst_data || !src_data)) + return -EINVAL; + if (src_data->len < min_len || data_len < src_data->len) + return -EINVAL; + return copy_struct_from_user(dst_data, data_len, src_data->uptr, + src_data->len); +} + +/** + * iommu_copy_struct_from_user - Copy iommu driver specific user space data + * @kdst: Pointer to an iommu driver specific user data that is defined in + * include/uapi/linux/iommufd.h + * @user_data: Pointer to a struct iommu_user_data for user space data info + * @data_type: The data type of the @kdst. Must match with @user_data->type + * @min_last: The last memember of the data structure @kdst points in the + * initial version. + * Return 0 for success, otherwise -error. + */ +#define iommu_copy_struct_from_user(kdst, user_data, data_type, min_last) \ + __iommu_copy_struct_from_user(kdst, user_data, data_type, \ + sizeof(*kdst), \ + offsetofend(typeof(*kdst), min_last)) + /** * struct iommu_ops - iommu ops and capabilities * @capable: check capability -- 2.34.1
