On Sun, Dec 09, 2018 at 11:58:04AM +0200, Leon Romanovsky wrote:
> From: Michael Guralnik <michaelgur@xxxxxxxxxxxx>
>
> Add a helper to zero fill fields before copying data to UVERBS_ATTR_STRUCT.
>
> As UVERBS_ATTR_STRUCT can be used as an extensible struct, we want to make
> sure that if the user supplies us with a struct that has new fields that
> we are not aware of, we return them zeroed to the user.
>
> This helper should be used when using UVERBS_ATTR_STRUCT for an extendable
> data structure and there is a need to make sure that extended members of
> the struct, that the kernel doesn't handle, are returned zeroed to the
> user. This is needed due to the fact that UVERBS_ATTR_STRUCT allows
> non-zero values for members after 'last' member.
>
> Signed-off-by: Michael Guralnik <michaelgur@xxxxxxxxxxxx>
> Reviewed-by: Majd Dibbiny <majd@xxxxxxxxxxxx>
> Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
> drivers/infiniband/core/uverbs_ioctl.c | 11 +++++++++++
> include/rdma/uverbs_ioctl.h | 7 +++++++
> 2 files changed, 18 insertions(+)
>
> diff --git a/drivers/infiniband/core/uverbs_ioctl.c b/drivers/infiniband/core/uverbs_ioctl.c
> index 3cc46447240e..8c81ff698052 100644
> +++ b/drivers/infiniband/core/uverbs_ioctl.c
> @@ -751,3 +751,14 @@ int _uverbs_get_const(s64 *to, const struct uverbs_attr_bundle *attrs_bundle,
> return 0;
> }
> EXPORT_SYMBOL(_uverbs_get_const);
> +
> +int uverbs_copy_to_struct_or_zero(const struct uverbs_attr_bundle *bundle,
> + size_t idx, const void *from, size_t size)
> +{
> + const struct uverbs_attr *attr = uverbs_attr_get(bundle, idx);
> +
> + if (clear_user(u64_to_user_ptr(attr->ptr_attr.data),
> + attr->ptr_attr.len))
Oh this is the function Doug and I were looking for in that other
thread.. Can you send a patch to make uverbs_response() use it?
Thanks,
Jason
