> From: Jiri Pirko <[email protected]>
> 
> Commit eb70d83a8645 ("RDMA/mana_ib: Adopt robust udata") renamed the
> "flags" field of struct mana_ib_create_cq to "comp_mask", as
> ib_copy_validate_udata_in_cm() only validates a member with that name.
> 
> The layout did not change, but the field has been a part of the UAPI since
> commit 44b607ad4cdf ("RDMA/mana_ib: implement uapi for creation of rnic
> cq"), so the rename breaks userspace referring to it, for example the mana
> provider of rdma-core assigning cmd_drv->flags.
> 
> Convert the field to a union providing both names, so that
> ib_copy_validate_udata_in_cm() still finds "comp_mask" and userspace keeps
> "flags", without having to add a helper for this single case.
> 

Thanks for the patch, but my understanding that it is a common practice to 
rename the fields,
and kernels headers should not accumulate historical names. 
I also faced a similar problem from renames in other providers, when I needed a 
new kernel header in rdma-core.
If this breaks your rdma-core in a PR, just remove the field rename in kernel 
update commit as that header update commit is not getting merged anyway from 
your PR.
My understanding that maintainers of RDMA-core will merge the kernel header 
update, and will bring this change from my PR:
https://github.com/linux-rdma/rdma-core/pull/1765/commits/0dcadd9316f1b98e21973e3a6e0f96186d49bd5a

- Konstantin

> Fixes: eb70d83a8645 ("RDMA/mana_ib: Adopt robust udata")
> Signed-off-by: Jiri Pirko <[email protected]>
> ---
>  include/uapi/rdma/mana-abi.h | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/include/uapi/rdma/mana-abi.h b/include/uapi/rdma/mana-abi.h
> index 410f0ddc8c89..431c7076f20a 100644
> --- a/include/uapi/rdma/mana-abi.h
> +++ b/include/uapi/rdma/mana-abi.h
> @@ -25,7 +25,10 @@ enum mana_ib_create_cq_flags {
> 
>  struct mana_ib_create_cq {
>       __aligned_u64 buf_addr;
> -     __u16   comp_mask;
> +     union {
> +             __u16   comp_mask;
> +             __u16   flags; /* the original name of the field */
> +     };
>       __u16   reserved0;
>       __u32   reserved1;
>  };
> --
> 2.54.0

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