Re: [PATCH v2 0/2] Add struct_offsetofend() for pointer arithmetic

[Kees Cook <kees@kernel.org>]

On Thu, Nov 12, 2026 at 10:29:32AM +0100, Bence Csokas wrote:
> A common usage pattern for offsetof() is the following:
> 
>   offsetof(typeof(*ptr), member)
> 
> This is exactly the definition of struct_offset(). Some call sites use
> offsetofend() instead of offsetof(). Add this variant, then replace all
> call sites with the corresponding macros.

Yeah, I think this is reasonable. I'd prefer to see the Coccinelle
script explicitly added to tools/coccinelle/api/ though, so it can be
trivially re-run as needed.

Also, while Alejandro is right about the needless outer parens, I think
I'd like to keep them just to match the other define, and they do no
harm.

-Kees

> 
> Signed-off-by: Bence Csokas <bence.csokas@arm.com>
> ---
> Changes in v2:
> - Use struct_offset() instead of reinventing it
> - Rename offsetofendp() to struct_offsetofend()
> - Merge the two treewide patches
> - Link to v1: https://patch.msgid.link/20261105-offsetof-v1-0-4153f5c10edc@arm.com
> 
> To: Kees Cook <kees@kernel.org>
> To: "Gustavo A. R. Silva" <gustavoars@kernel.org>
> To: Marcel Holtmann <marcel@holtmann.org>
> To: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
> To: Sumit Semwal <sumit.semwal@linaro.org>
> To: Christian König <christian.koenig@amd.com>
> To: Philipp Stanner <phasta@kernel.org>
> To: Sudeep Holla <sudeep.holla@kernel.org>
> To: Cristian Marussi <cristian.marussi@arm.com>
> To: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> To: Maxime Ripard <mripard@kernel.org>
> To: Thomas Zimmermann <tzimmermann@suse.de>
> To: David Airlie <airlied@gmail.com>
> To: Simona Vetter <simona@ffwll.ch>
> To: Jani Nikula <jani.nikula@linux.intel.com>
> To: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
> To: Rodrigo Vivi <rodrigo.vivi@intel.com>
> To: Tvrtko Ursulin <tursulin@ursulin.net>
> To: Lyude Paul <lyude@redhat.com>
> To: Danilo Krummrich <dakr@kernel.org>
> To: Zack Rusin <zack.rusin@broadcom.com>
> To: Broadcom internal kernel review list <bcm-kernel-feedback-list@broadcom.com>
> To: Selvin Xavier <selvin.xavier@broadcom.com>
> To: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
> To: Jason Gunthorpe <jgg@ziepe.ca>
> To: Leon Romanovsky <leon@kernel.org>
> To: Chengchang Tang <tangchengchang@huawei.com>
> To: Junxian Huang <huangjunxian6@hisilicon.com>
> To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> To: Hans de Goede <hansg@kernel.org>
> To: Mauro Carvalho Chehab <mchehab@kernel.org>
> To: Haiyang Zhang <haiyangz@microsoft.com>
> To: Wei Liu <wei.liu@kernel.org>
> To: Dexuan Cui <decui@microsoft.com>
> To: Andrew Lunn <andrew+netdev@lunn.ch>
> To: "David S. Miller" <davem@davemloft.net>
> To: Eric Dumazet <edumazet@kernel.org>
> To: Jakub Kicinski <kuba@kernel.org>
> To: Paolo Abeni <pabeni@redhat.com>
> To: Miri Korenblit <miriam.rachel.korenblit@intel.com>
> To: Jes Sorensen <Jes.Sorensen@gmail.com>
> To: Ping-Ke Shih <pkshih@realtek.com>
> To: Johannes Berg <johannes@sipsolutions.net>
> To: Benson Leung <bleung@chromium.org>
> To: Tzung-Bi Shih <tzungbi@kernel.org>
> To: Guenter Roeck <groeck@chromium.org>
> To: Nilesh Javali <njavali@marvell.com>
> To: GR-QLogic-Storage-Upstream@marvell.com
> To: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
> To: "Martin K. Petersen" <mkp@kernel.org>
> Cc: linux-hardening@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-bluetooth@vger.kernel.org
> Cc: linux-media@vger.kernel.org
> Cc: dri-devel@lists.freedesktop.org
> Cc: linaro-mm-sig@lists.linaro.org
> Cc: arm-scmi@vger.kernel.org
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: intel-gfx@lists.freedesktop.org
> Cc: nouveau@lists.freedesktop.org
> Cc: linux-rdma@vger.kernel.org
> Cc: linux-hyperv@vger.kernel.org
> Cc: netdev@vger.kernel.org
> Cc: linux-wireless@vger.kernel.org
> Cc: chrome-platform@lists.linux.dev
> Cc: linux-scsi@vger.kernel.org
> 
> ---
> Bence Csokas (2):
>       stddef: Add offsetofend() variant of struct_offset()
>       treewide: Use struct_offset()
> 
>  drivers/bluetooth/btmrvl_main.c                    | 12 +++++-----
>  drivers/dma-buf/dma-resv.c                         |  2 +-
>  drivers/firmware/arm_scmi/base.c                   |  2 +-
>  drivers/gpu/drm/drm_edid.c                         | 26 +++++++++++-----------
>  drivers/gpu/drm/i915/gem/i915_gem_object.c         |  4 ++--
>  drivers/gpu/drm/i915/i915_active.c                 |  2 +-
>  drivers/gpu/drm/i915/i915_sw_fence_work.c          |  2 +-
>  .../gpu/drm/nouveau/nvkm/subdev/gsp/rm/r535/gsp.c  |  2 +-
>  drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c            | 12 +++++-----
>  drivers/infiniband/hw/bnxt_re/qplib_fp.c           |  2 +-
>  drivers/infiniband/hw/hns/hns_roce_cq.c            |  4 ++--
>  drivers/infiniband/hw/hns/hns_roce_qp.c            |  6 ++---
>  drivers/media/usb/uvc/uvc_v4l2.c                   |  4 ++--
>  drivers/net/hyperv/rndis_filter.c                  |  2 +-
>  drivers/net/wireless/intel/iwlwifi/iwl-drv.c       |  2 +-
>  drivers/net/wireless/intel/iwlwifi/mvm/rs-fw.c     |  2 +-
>  drivers/net/wireless/intel/iwlwifi/mvm/rs.c        |  2 +-
>  .../net/wireless/intel/iwlwifi/pcie/ctxt-info-v2.c |  5 ++---
>  drivers/net/wireless/realtek/rtl8xxxu/core.c       |  2 +-
>  drivers/net/wireless/realtek/rtw88/fw.c            |  2 +-
>  drivers/net/wireless/realtek/rtw89/core.c          |  2 +-
>  drivers/net/wireless/realtek/rtw89/fw.c            |  8 +++----
>  drivers/net/wireless/virtual/mac80211_hwsim_main.c |  4 ++--
>  drivers/platform/chrome/cros_ec_lightbar.c         |  4 ++--
>  drivers/scsi/qla2xxx/qla_gs.c                      |  2 +-
>  drivers/scsi/qla2xxx/qla_mbx.c                     |  2 +-
>  drivers/scsi/qla2xxx/qla_os.c                      |  2 +-
>  drivers/scsi/qla2xxx/qla_tmpl.c                    |  4 ++--
>  drivers/scsi/scsi_transport_fc.c                   |  2 +-
>  include/linux/overflow.h                           | 12 ++++++++++
>  30 files changed, 75 insertions(+), 64 deletions(-)
> ---
> base-commit: 9d66f26fefacebfeed15de31c1123451a17ff119
> change-id: 20261105-offsetof-f62aa6348f0d
> 
> Best regards,
> --  
> Bence Csokas <bence.csokas@arm.com>
> 

-- 
Kees Cook