linux-stable.git/Documentation/userspace-api, branch v5.15.211

crypto: qat - remove unused character device and IOCTLs

2026-07-04T11:39:41+00:00

[ Upstream commit d237230728c567297f2f98b425d63156ab2ed17f ]

The QAT driver exposes a character device (qat_adf_ctl) with IOCTLs
for device configuration, start, stop, status query and enumeration.
These IOCTLs are not part of any public uAPI header and have no known
in-tree or out-of-tree users. Device lifecycle is already managed via
sysfs.

The ioctl interface also increases the attack surface and is the
subject of a number of bug reports.

Remove the character device, the IOCTL definitions, and the related
data structures (adf_dev_status_info, adf_user_cfg_key_val,
adf_user_cfg_section, adf_user_cfg_ctl_data). Drop the now-unused
adf_cfg_user.h header and strip adf_ctl_drv.c down to the minimal
module_init/module_exit hooks for workqueue, AER, and crypto/compression
algorithm registration.

Clean up leftover dead code that was only reachable from the removed
IOCTL paths: adf_cfg_del_all(), adf_devmgr_verify_id(),
adf_devmgr_get_num_dev(), adf_devmgr_get_dev_by_id(),
adf_get_vf_real_id() and the unused ADF_CFG macros.

Additionally, drop the entry associated to QAT IOCTLs in
ioctl-number.rst.

Cc: stable@vger.kernel.org
Fixes: d8cba25d2c68 ("crypto: qat - Intel(R) QAT driver framework")
Reported-by: Zhi Wang 
Reported-by: Bin Yu 
Reported-by: MingYu Wang 
Closes: https://lore.kernel.org/all/61d6d499.ab89.19b9b7f3186.Coremail.wangzhi_xd@stu.xidian.edu.cn/
Link: https://lore.kernel.org/all/20260508034841.256794-1-w15303746062@163.com/
Link: https://lore.kernel.org/all/20260508023542.256299-1-w15303746062@163.com/
Link: https://lore.kernel.org/all/20260504025120.98242-1-w15303746062@163.com/
Signed-off-by: Giovanni Cabiddu 
Reviewed-by: Ahsan Atta 
Signed-off-by: Herbert Xu 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

Documentation: ioctl-number: Extend "Include File" column width

2026-07-04T11:39:41+00:00

[ Upstream commit 15afd5def819e4df2a29cef6fcfa6ae7ba167c0f ]

Extend width of "Include File" column to fit full path to
papr-physical-attestation.h in later commit.

Reviewed-by: Haren Myneni 
Signed-off-by: Bagas Sanjaya 
Acked-by: Madhavan Srinivasan 
Signed-off-by: Jonathan Corbet 
Link: https://lore.kernel.org/r/20250714015711.14525-3-bagasdotme@gmail.com
Stable-dep-of: d237230728c5 ("crypto: qat - remove unused character device and IOCTLs")
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

Remove DECnet support from kernel

2023-06-21T13:59:15+00:00

commit 1202cdd665315c525b5237e96e0bedc76d7e754f upstream.

DECnet is an obsolete network protocol that receives more attention
from kernel janitors than users. It belongs in computer protocol
history museum not in Linux kernel.

It has been "Orphaned" in kernel since 2010. The iproute2 support
for DECnet was dropped in 5.0 release. The documentation link on
Sourceforge says it is abandoned there as well.

Leave the UAPI alone to keep userspace programs compiling.
This means that there is still an empty neighbour table
for AF_DECNET.

The table of /proc/sys/net entries was updated to match
current directories and reformatted to be alphabetical.

Signed-off-by: Stephen Hemminger 
Acked-by: David Ahern 
Acked-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

media: hevc: Embedded indexes in RPS

2022-08-17T12:23:31+00:00

[ Upstream commit d95a63daca85f4bca3b70e622c75586b5bf0ea5c ]

Reference Picture Set lists provide indices of short and long term
reference in DBP array.
Fix Hantro to not do a look up in DBP entries.
Make documentation more clear about it.

[hverkuil: fix typo in commit log]

Signed-off-by: Benjamin Gaignard 
Reviewed-by: Ezequiel Garcia 
Signed-off-by: Hans Verkuil 
Signed-off-by: Mauro Carvalho Chehab 
Signed-off-by: Sasha Levin

landlock: Reduce the maximum number of layers to 16

2022-06-09T08:23:24+00:00

commit 75c542d6c6cc48720376862d5496d51509160dfd upstream.

The maximum number of nested Landlock domains is currently 64.  Because
of the following fix and to help reduce the stack size, let's reduce it
to 16.  This seems large enough for a lot of use cases (e.g. sandboxed
init service, spawning a sandboxed SSH service, in nested sandboxed
containers).  Reducing the number of nested domains may also help to
discover misuse of Landlock (e.g. creating a domain per rule).

Add and use a dedicated layer_mask_t typedef to fit with the number of
layers.  This might be useful when changing it and to keep it consistent
with the maximum number of layers.

Reviewed-by: Paul Moore 
Link: https://lore.kernel.org/r/20220506161102.525323-3-mic@digikod.net
Cc: stable@vger.kernel.org
Signed-off-by: Mickaël Salaün 
Signed-off-by: Greg Kroah-Hartman

ptp: Document the PTP_CLK_MAGIC ioctl number

2021-10-28T00:02:51+00:00

Add PTP_CLK_MAGIC to the userspace-api/ioctl/ioctl-number.rst
documentation file.

Fixes: d94ba80ebbea ("ptp: Added a brand new class driver for ptp clocks.")
Signed-off-by: Randy Dunlap 
Cc: Richard Cochran 
Cc: John Stultz 
Cc: Jonathan Corbet 
Link: https://lore.kernel.org/r/20211024163831.10200-1-rdunlap@infradead.org
Signed-off-by: Jakub Kicinski

VDUSE: fix documentation underline warning

2021-10-13T12:42:07+00:00

Fix a VDUSE documentation build warning:

Documentation/userspace-api/vduse.rst:21: WARNING: Title underline too short.

Fixes: 7bc7f61897b6 ("Documentation: Add documentation for VDUSE")
Signed-off-by: Randy Dunlap 
Cc: Xie Yongji 
Cc: Jason Wang 
Cc: Michael S. Tsirkin 
Cc: virtualization@lists.linux-foundation.org
Cc: Jonathan Corbet 
Cc: linux-doc@vger.kernel.org
Link: https://lore.kernel.org/r/20211006202904.30241-1-rdunlap@infradead.org
Signed-off-by: Michael S. Tsirkin 
Reviewed-by: Xie Yongji 
Acked-by: Jason Wang

Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

2021-09-11T21:48:42+00:00

Pull virtio updates from Michael Tsirkin:

 - vduse driver ("vDPA Device in Userspace") supporting emulated virtio
   block devices

 - virtio-vsock support for end of record with SEQPACKET

 - vdpa: mac and mq support for ifcvf and mlx5

 - vdpa: management netlink for ifcvf

 - virtio-i2c, gpio dt bindings

 - misc fixes and cleanups

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (39 commits)
  Documentation: Add documentation for VDUSE
  vduse: Introduce VDUSE - vDPA Device in Userspace
  vduse: Implement an MMU-based software IOTLB
  vdpa: Support transferring virtual addressing during DMA mapping
  vdpa: factor out vhost_vdpa_pa_map() and vhost_vdpa_pa_unmap()
  vdpa: Add an opaque pointer for vdpa_config_ops.dma_map()
  vhost-iotlb: Add an opaque pointer for vhost IOTLB
  vhost-vdpa: Handle the failure of vdpa_reset()
  vdpa: Add reset callback in vdpa_config_ops
  vdpa: Fix some coding style issues
  file: Export receive_fd() to modules
  eventfd: Export eventfd_wake_count to modules
  iova: Export alloc_iova_fast() and free_iova_fast()
  virtio-blk: remove unneeded "likely" statements
  virtio-balloon: Use virtio_find_vqs() helper
  vdpa: Make use of PFN_PHYS/PFN_UP/PFN_DOWN helper macro
  vsock_test: update message bounds test for MSG_EOR
  af_vsock: rename variables in receive loop
  virtio/vsock: support MSG_EOR bit processing
  vhost/vsock: support MSG_EOR bit processing
  ...

Documentation: Add documentation for VDUSE

2021-09-06T11:20:58+00:00

VDUSE (vDPA Device in Userspace) is a framework to support
implementing software-emulated vDPA devices in userspace. This
document is intended to clarify the VDUSE design and usage.

Signed-off-by: Xie Yongji 
Acked-by: Jason Wang 
Link: https://lore.kernel.org/r/20210831103634.33-14-xieyongji@bytedance.com
Signed-off-by: Michael S. Tsirkin

vduse: Introduce VDUSE - vDPA Device in Userspace

2021-09-06T11:20:58+00:00

This VDUSE driver enables implementing software-emulated vDPA
devices in userspace. The vDPA device is created by
ioctl(VDUSE_CREATE_DEV) on /dev/vduse/control. Then a char device
interface (/dev/vduse/$NAME) is exported to userspace for device
emulation.

In order to make the device emulation more secure, the device's
control path is handled in kernel. A message mechnism is introduced
to forward some dataplane related control messages to userspace.

And in the data path, the DMA buffer will be mapped into userspace
address space through different ways depending on the vDPA bus to
which the vDPA device is attached. In virtio-vdpa case, the MMU-based
software IOTLB is used to achieve that. And in vhost-vdpa case, the
DMA buffer is reside in a userspace memory region which can be shared
to the VDUSE userspace processs via transferring the shmfd.

For more details on VDUSE design and usage, please see the follow-on
Documentation commit.

NB(mst): when merging this with
b542e383d8c0 ("eventfd: Make signal recursion protection a task bit")
replace eventfd_signal_count with eventfd_signal_allowed,
and drop the previous
("eventfd: Export eventfd_wake_count to modules").

Signed-off-by: Xie Yongji 
Acked-by: Jason Wang 
Link: https://lore.kernel.org/r/20210831103634.33-13-xieyongji@bytedance.com
Signed-off-by: Michael S. Tsirkin