Re: [PATCH rdma-next v7 03/15] RDMA/core: Introduce generic buffer descriptor infrastructure for umem

[Jason Gunthorpe <jgg@ziepe.ca>]

On Tue, May 26, 2026 at 04:41:40PM +0200, Jiri Pirko wrote:

> diff --git a/drivers/infiniband/core/uverbs_ioctl.c b/drivers/infiniband/core/uverbs_ioctl.c
> index 6a78288e27a1..457c49d44467 100644
> --- a/drivers/infiniband/core/uverbs_ioctl.c
> +++ b/drivers/infiniband/core/uverbs_ioctl.c
> @@ -597,6 +597,31 @@ void uverbs_fill_udata(struct uverbs_attr_bundle *bundle,
>  	}
>  }
>  
> +/**
> + * uverbs_attr_get_buffer_desc - Read a buffer descriptor from a uverbs attr.
> + * @attrs:   uverbs attribute bundle.
> + * @attr_id: id of an UVERBS_ATTR_UMEM-typed attribute.
> + * @desc:    descriptor to fill.
> + *
> + * Return: 0 on success, -ENOENT if @attr_id is not set, -EINVAL on a
> + * malformed descriptor.
> + */
> +int uverbs_attr_get_buffer_desc(const struct uverbs_attr_bundle *attrs,
> +				u16 attr_id,
> +				struct ib_uverbs_buffer_desc *desc)
> +{
> +	int ret;
> +
> +	ret = uverbs_copy_from(desc, attrs, attr_id);
> +	if (ret)
> +		return ret;
> +	if (desc->flags & ~IB_UVERBS_BUFFER_DESC_FLAGS_KNOWN_MASK)
> +		return -EINVAL;
> +	desc->optional_flags &= IB_UVERBS_BUFFER_DESC_OPTIONAL_FLAGS_KNOWN_MASK;
> +	return 0;
> +}
> +EXPORT_SYMBOL(uverbs_attr_get_buffer_desc);

This function has to go into ib_core_uverbs.c if umem is going to call
it:

ld: drivers/infiniband/core/umem.o: in function `ib_umem_get_attr':
umem.c:(.text+0x783): undefined reference to `uverbs_attr_get_buffer_desc'
ld: drivers/infiniband/core/umem.o: in function `ib_umem_get_attr_or_va':
umem.c:(.text+0x82d): undefined reference to `uverbs_attr_get_buffer_desc'
make[3]: *** [../scripts/Makefile.vmlinux:72: vmlinux.unstripped] Error 1

Jason