From: Jason Gunthorpe <jgg@ziepe.ca>
To: Jiri Pirko <jiri@resnulli.us>
Cc: linux-rdma@vger.kernel.org, leon@kernel.org, mrgolin@amazon.com,
gal.pressman@linux.dev, sleybo@amazon.com, parav@nvidia.com,
mbloch@nvidia.com, yanjun.zhu@linux.dev,
marco.crivellari@suse.com, roman.gushchin@linux.dev,
phaddad@nvidia.com, lirongqing@baidu.com, ynachum@amazon.com,
huangjunxian6@hisilicon.com, kalesh-anakkur.purayil@broadcom.com,
ohartoov@nvidia.com, michaelgur@nvidia.com, shayd@nvidia.com,
edwards@nvidia.com, sriharsha.basavapatna@broadcom.com,
andrew.gospodarek@broadcom.com, selvin.xavier@broadcom.com
Subject: Re: [PATCH rdma-next v3 17/17] RDMA/uverbs: Track attr consumption and warn on unused attrs
Date: Wed, 6 May 2026 10:56:23 -0300 [thread overview]
Message-ID: <aftIh+qQ0bl++qxM@ziepe.ca> (raw)
In-Reply-To: <20260504135731.2345383-18-jiri@resnulli.us>
On Mon, May 04, 2026 at 03:57:31PM +0200, Jiri Pirko wrote:
> From: Jiri Pirko <jiri@nvidia.com>
>
> Catch userspace passing attributes that nothing in the kernel
> reads which would be a sign that the driver doesn't support
> a feature, an attr was forgotten in a refactor, or userspace is buggy.
> UHW and PTR_OUT attrs are exempt; destroy attrs are marked consumed by
> the framework. Gate on CONFIG_DEBUG_KERNEL to avoid overhead on
> production kernels.
This is maybe interesting debugging for a version matched rdma-core
But the idea the kernel ignores an attribute is part of the protocol,
if the attribute is marked mandatory by userspace then the kernel will
fail the system call.
I don't remember how often this ends up being used, and I think it is
a bit rare, but it is there.
Jason
next prev parent reply other threads:[~2026-05-06 13:56 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-04 13:57 [PATCH rdma-next v3 00/17] RDMA: Introduce generic buffer descriptor infrastructure for umem Jiri Pirko
2026-05-04 13:57 ` [PATCH rdma-next v3 01/17] RDMA/umem: Rename ib_umem_get() to ib_umem_get_va() Jiri Pirko
2026-05-04 13:57 ` [PATCH rdma-next v3 02/17] RDMA/umem: Split ib_umem_get_va() into a thin wrapper around __ib_umem_get_va() Jiri Pirko
2026-05-04 13:57 ` [PATCH rdma-next v3 03/17] RDMA/core: Introduce generic buffer descriptor infrastructure for umem Jiri Pirko
2026-05-06 13:37 ` Jason Gunthorpe
2026-05-06 14:14 ` Jiri Pirko
2026-05-04 13:57 ` [PATCH rdma-next v3 04/17] RDMA/umem: Route ib_umem_get_va() through ib_umem_get() Jiri Pirko
2026-05-04 13:57 ` [PATCH rdma-next v3 05/17] RDMA/uverbs: Inline _uverbs_get_const_{signed,unsigned}() Jiri Pirko
2026-05-04 13:57 ` [PATCH rdma-next v3 06/17] RDMA/uverbs: Push out CQ buffer umem processing into a helper Jiri Pirko
2026-05-04 13:57 ` [PATCH rdma-next v3 07/17] RDMA/uverbs: Add CQ buffer UMEM attribute and driver helpers Jiri Pirko
2026-05-06 13:46 ` Jason Gunthorpe
2026-05-06 14:27 ` Jiri Pirko
2026-05-04 13:57 ` [PATCH rdma-next v3 08/17] RDMA/efa: Use ib_umem_get_cq_buf() for user CQ buffer Jiri Pirko
2026-05-06 13:51 ` Jason Gunthorpe
2026-05-06 14:32 ` Jiri Pirko
2026-05-04 13:57 ` [PATCH rdma-next v3 09/17] RDMA/mlx5: Use ib_umem_get_cq_buf_or_va() " Jiri Pirko
2026-05-04 13:57 ` [PATCH rdma-next v3 10/17] RDMA/bnxt_re: " Jiri Pirko
2026-05-04 13:57 ` [PATCH rdma-next v3 11/17] RDMA/mlx4: Use ib_umem_get_cq_buf() " Jiri Pirko
2026-05-04 13:57 ` [PATCH rdma-next v3 12/17] RDMA/uverbs: Remove legacy umem field from struct ib_cq Jiri Pirko
2026-05-04 13:57 ` [PATCH rdma-next v3 13/17] RDMA/uverbs: Use UMEM attributes for QP creation Jiri Pirko
2026-05-06 13:43 ` Jason Gunthorpe
2026-05-06 14:17 ` Jiri Pirko
2026-05-04 13:57 ` [PATCH rdma-next v3 14/17] RDMA/mlx5: Use UMEM attributes for QP buffers in create_qp Jiri Pirko
2026-05-04 13:57 ` [PATCH rdma-next v3 15/17] RDMA/mlx5: Use UMEM attribute for CQ doorbell record Jiri Pirko
2026-05-04 13:57 ` [PATCH rdma-next v3 16/17] RDMA/mlx5: Use UMEM attribute for QP " Jiri Pirko
2026-05-04 13:57 ` [PATCH rdma-next v3 17/17] RDMA/uverbs: Track attr consumption and warn on unused attrs Jiri Pirko
2026-05-06 13:56 ` Jason Gunthorpe [this message]
2026-05-06 14:22 ` Jiri Pirko
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