linux-kernel - [PATCH v2 0/3] vfio: use __aligned

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20230829182720.331083-1-stefanha@redhat.com>
Date:   Tue, 29 Aug 2023 14:27:17 -0400
From:   Stefan Hajnoczi <stefanha@...hat.com>
To:     kvm@...r.kernel.org
Cc:     David Laight <David.Laight@...LAB.COM>,
        linux-kernel@...r.kernel.org, "Tian, Kevin" <kevin.tian@...el.com>,
        Alex Williamson <alex.williamson@...hat.com>,
        Jason Gunthorpe <jgg@...pe.ca>,
        Stefan Hajnoczi <stefanha@...hat.com>
Subject: [PATCH v2 0/3] vfio: use __aligned_u64 for ioctl structs

v2:
- Rebased onto https://github.com/awilliam/linux-vfio.git next to get the
  vfio_iommu_type1_info pad field [Kevin]
- Fixed min(minsz, sizeof(dmabuf)) -> min(dmabuf.argsz, sizeof(dmabuf)) [Jason, Kevin]
- Squashed Patch 3 (vfio_iommu_type1_info) into Patch 1 since it is trivial now
  that the padding field is already there.

Jason Gunthorpe <jgg@...dia.com> pointed out that u64 VFIO ioctl struct fields
have architecture-dependent alignment. iommufd already uses __aligned_u64 to
avoid this problem.

See the __aligned_u64 typedef in <uapi/linux/types.h> for details on why it is
a good idea for kernel<->user interfaces.

This series modifies the VFIO ioctl structs to use __aligned_u64. Some of the
changes preserve the existing memory layout on all architectures, so I put them
together into the first patch. The remaining patches are for structs where
explanation is necessary about why changing the memory layout does not break
the uapi.

Stefan Hajnoczi (3):
  vfio: trivially use __aligned_u64 for ioctl structs
  vfio: use __aligned_u64 in struct vfio_device_gfx_plane_info
  vfio: use __aligned_u64 in struct vfio_device_ioeventfd

 include/uapi/linux/vfio.h        | 26 ++++++++++++++------------
 drivers/gpu/drm/i915/gvt/kvmgt.c |  4 +++-
 samples/vfio-mdev/mbochs.c       |  6 ++++--
 samples/vfio-mdev/mdpy.c         |  4 +++-
 4 files changed, 24 insertions(+), 16 deletions(-)

-- 
2.41.0