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iommu: Add iommu_copy_struct_from_user helper

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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.

Link: https://lore.kernel.org/r/20231026043938.63898-9-yi.l.liu@intel.com
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Co-developed-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
This commit is contained in:
Nicolin Chen 2023-10-25 21:39:36 -07:00 committed by Jason Gunthorpe
parent bd529dbb66
commit e9d36c07bb
1 changed files with 40 additions and 0 deletions
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40
include/linux/iommu.h
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@ -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