linux-stable.git/Documentation/userspace-api, branch v6.10

tracing: Have memmapped ring buffer use ioctl of "R" range 0x20-2F

2024-07-03T20:40:45+00:00

To prevent conflicts with other ioctl numbers to allow strace to have an
idea of what is happening, add the range of ioctls for the trace buffer
mapping from _IO("T", 0x1) to the range of "R" 0x20 - 0x2F.

Link: https://lore.kernel.org/linux-trace-kernel/20240630105322.GA17573@altlinux.org/
Link: https://lore.kernel.org/linux-trace-kernel/20240630213626.GA23566@altlinux.org/

Cc: Jonathan Corbet 
Fixes: cf9f0f7c4c5bb ("tracing: Allow user-space mapping of the ring-buffer")
Link: https://lore.kernel.org/20240702153354.367861db@rorschach.local.home
Reported-by: "Dmitry V. Levin" 
Reviewed-by: Mathieu Desnoyers 
Acked-by: Masami Hiramatsu (Google) 
Signed-off-by: Steven Rostedt (Google)

mm/memfd: add documentation for MFD_NOEXEC_SEAL MFD_EXEC

2024-06-15T17:43:07+00:00

When MFD_NOEXEC_SEAL was introduced, there was one big mistake: it didn't
have proper documentation.  This led to a lot of confusion, especially
about whether or not memfd created with the MFD_NOEXEC_SEAL flag is
sealable.  Before MFD_NOEXEC_SEAL, memfd had to explicitly set
MFD_ALLOW_SEALING to be sealable, so it's a fair question.

As one might have noticed, unlike other flags in memfd_create,
MFD_NOEXEC_SEAL is actually a combination of multiple flags.  The idea is
to make it easier to use memfd in the most common way, which is NOEXEC +
F_SEAL_EXEC + MFD_ALLOW_SEALING.  This works with sysctl vm.noexec to help
existing applications move to a more secure way of using memfd.

Proposals have been made to put MFD_NOEXEC_SEAL non-sealable, unless
MFD_ALLOW_SEALING is set, to be consistent with other flags [1], Those
are based on the viewpoint that each flag is an atomic unit, which is a
reasonable assumption.  However, MFD_NOEXEC_SEAL was designed with the
intent of promoting the most secure method of using memfd, therefore a
combination of multiple functionalities into one bit.

Furthermore, the MFD_NOEXEC_SEAL has been added for more than one year,
and multiple applications and distributions have backported and utilized
it.  Altering ABI now presents a degree of risk and may lead to
disruption.

MFD_NOEXEC_SEAL is a new flag, and applications must change their code to
use it.  There is no backward compatibility problem.

When sysctl vm.noexec == 1 or 2, applications that don't set
MFD_NOEXEC_SEAL or MFD_EXEC will get MFD_NOEXEC_SEAL memfd.  And
old-application might break, that is by-design, in such a system vm.noexec
= 0 shall be used.  Also no backward compatibility problem.

I propose to include this documentation patch to assist in clarifying the
semantics of MFD_NOEXEC_SEAL, thereby preventing any potential future
confusion.

Finally, I would like to express my gratitude to David Rheinsberg and
Barnabás Pőcze for initiating the discussion on the topic of sealability.

[1]
https://lore.kernel.org/lkml/20230714114753.170814-1-david@readahead.eu/

[jeffxu@chromium.org: updates per Randy]
  Link: https://lkml.kernel.org/r/20240611034903.3456796-2-jeffxu@chromium.org
[jeffxu@chromium.org: v3]
  Link: https://lkml.kernel.org/r/20240611231409.3899809-2-jeffxu@chromium.org
Link: https://lkml.kernel.org/r/20240607203543.2151433-2-jeffxu@google.com
Signed-off-by: Jeff Xu 
Reviewed-by: Randy Dunlap 
Cc: Aleksa Sarai 
Cc: Barnabás Pőcze 
Cc: Daniel Verkamp 
Cc: David Rheinsberg 
Cc: Dmitry Torokhov 
Cc: Hugh Dickins 
Cc: Jorge Lucangeli Obes 
Cc: Kees Cook 
Cc: Shuah Khan 
Signed-off-by: Andrew Morton

media: Documentation: v4l: Fix ACTIVE route flag

2024-05-28T06:00:14+00:00

The documentation in one occasion mentions the
VIDIOC_SUBDEV_STREAM_FL_ACTIVE flag. This was meant to be
V4L2_SUBDEV_STREAM_FL_ACTIVE as it's a flag, not an IOCTL. Fix it.

Fixes: cd2c75454d74 ("media: Documentation: Document S_ROUTING behaviour")
Reported-by: Samuel Wein PhD 
Signed-off-by: Sakari Ailus 
Signed-off-by: Hans Verkuil

mseal: add documentation

2024-05-24T02:40:26+00:00

Add documentation for mseal().

Link: https://lkml.kernel.org/r/20240415163527.626541-5-jeffxu@chromium.org
Signed-off-by: Jeff Xu 
Reviewed-by: Kees Cook 
Reviewed-by: Liam R. Howlett 
Cc: Dave Hansen 
Cc: Greg Kroah-Hartman 
Cc: Guenter Roeck 
Cc: Jann Horn 
Cc: Jeff Xu 
Cc: Jonathan Corbet 
Cc: Jorge Lucangeli Obes 
Cc: Linus Torvalds 
Cc: Matthew Wilcox (Oracle) 
Cc: Muhammad Usama Anjum 
Cc: Pedro Falcato 
Cc: Stephen Röttger 
Cc: Suren Baghdasaryan 
Cc: Amer Al Shanawany 
Cc: Javier Carrasco 
Cc: Shuah Khan 
Signed-off-by: Andrew Morton

Merge tag 'char-misc-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

2024-05-22T19:26:46+00:00

Pull char/misc and other driver subsystem updates from Greg KH:
 "Here is the big set of char/misc and other driver subsystem updates
  for 6.10-rc1. Nothing major here, just lots of new drivers and updates
  for apis and new hardware types. Included in here are:

   - big IIO driver updates with more devices and drivers added

   - fpga driver updates

   - hyper-v driver updates

   - uio_pruss driver removal, no one uses it, other drivers control the
     same hardware now

   - binder minor updates

   - mhi driver updates

   - excon driver updates

   - counter driver updates

   - accessability driver updates

   - coresight driver updates

   - other hwtracing driver updates

   - nvmem driver updates

   - slimbus driver updates

   - spmi driver updates

   - other smaller misc and char driver updates

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'char-misc-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (319 commits)
  misc: ntsync: mark driver as "broken" to prevent from building
  spmi: pmic-arb: Add multi bus support
  spmi: pmic-arb: Register controller for bus instead of arbiter
  spmi: pmic-arb: Make core resources acquiring a version operation
  spmi: pmic-arb: Make the APID init a version operation
  spmi: pmic-arb: Fix some compile warnings about members not being described
  dt-bindings: spmi: Deprecate qcom,bus-id
  dt-bindings: spmi: Add X1E80100 SPMI PMIC ARB schema
  spmi: pmic-arb: Replace three IS_ERR() calls by null pointer checks in spmi_pmic_arb_probe()
  spmi: hisi-spmi-controller: Do not override device identifier
  dt-bindings: spmi: hisilicon,hisi-spmi-controller: clean up example
  dt-bindings: spmi: hisilicon,hisi-spmi-controller: fix binding references
  spmi: make spmi_bus_type const
  extcon: adc-jack: Document missing struct members
  extcon: realtek: Remove unused of_gpio.h
  extcon: usbc-cros-ec: Convert to platform remove callback returning void
  extcon: usb-gpio: Convert to platform remove callback returning void
  extcon: max77843: Convert to platform remove callback returning void
  extcon: max3355: Convert to platform remove callback returning void
  extcon: intel-mrfld: Convert to platform remove callback returning void
  ...

Merge tag 'landlock-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux

2024-05-18T17:48:07+00:00

Pull landlock updates from Mickaël Salaün:
 "This brings ioctl control to Landlock, contributed by Günther Noack.
  This also adds him as a Landlock reviewer, and fixes an issue in the
  sample"

* tag 'landlock-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux:
  MAINTAINERS: Add Günther Noack as Landlock reviewer
  fs/ioctl: Add a comment to keep the logic in sync with LSM policies
  MAINTAINERS: Notify Landlock maintainers about changes to fs/ioctl.c
  landlock: Document IOCTL support
  samples/landlock: Add support for LANDLOCK_ACCESS_FS_IOCTL_DEV
  selftests/landlock: Exhaustive test for the IOCTL allow-list
  selftests/landlock: Check IOCTL restrictions for named UNIX domain sockets
  selftests/landlock: Test IOCTLs on named pipes
  selftests/landlock: Test ioctl(2) and ftruncate(2) with open(O_PATH)
  selftests/landlock: Test IOCTL with memfds
  selftests/landlock: Test IOCTL support
  landlock: Add IOCTL access right for character and block devices
  samples/landlock: Fix incorrect free in populate_ruleset_net

Merge tag 'media/v6.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media

2024-05-16T15:45:44+00:00

Pull media updates from Mauro Carvalho Chehab:

 - New V4L2 ioctl VIDIOC_REMOVE_BUFS

 - experimental support for using generic metaformats on V4L2 core

 - New drivers: Intel IPU6 controller driver, Broadcom BCM283x/BCM271x

 - More cleanups at atomisp driver

 - Usual bunch of driver cleanups, improvements and fixes

* tag 'media/v6.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (328 commits)
  media: bcm2835-unicam: Depend on COMMON_CLK
  Revert "media: v4l2-ctrls: show all owned controls in log_status"
  media: ov2740: Ensure proper reset sequence on probe()
  media: intel/ipu6: Don't print user-triggerable errors to kernel log
  media: bcm2835-unicam: Fix driver path in MAINTAINERS
  media: bcm2835-unicam: Fix a NULL vs IS_ERR() check
  media: bcm2835-unicam: Do not print error when irq not found
  media: bcm2835-unicam: Do not replace IRQ retcode during probe
  media: bcm2835-unicam: Convert to platform remove callback returning void
  media: media: intel/ipu6: Fix spelling mistake "remappinp" -> "remapping"
  media: intel/ipu6: explicitly include vmalloc.h
  media: cec.h: Fix kerneldoc
  media: uvcvideo: Refactor iterators
  media: v4l: async: refactor v4l2_async_create_ancillary_links
  media: intel/ipu6: Don't re-allocate memory for firmware
  media: dvb-frontends: tda10048: Fix integer overflow
  media: tc358746: Use the correct div_ function
  media: i2c: st-mipid02: Use the correct div function
  media: tegra-vde: Refactor timeout handling
  media: stk1160: Use min macro
  ...

Merge tag 'net-next-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

2024-05-15T02:42:24+00:00

Pull networking updates from Jakub Kicinski:
"Core & protocols:

- Complete rework of garbage collection of AF_UNIX sockets.

AF_UNIX is prone to forming reference count cycles due to fd
passing functionality. New method based on Tarjan's Strongly
Connected Components algorithm should be both faster and remove a
lot of workarounds we accumulated over the years.

- Add TCP fraglist GRO support, allowing chaining multiple TCP
packets and forwarding them together. Useful for small switches /
routers which lack basic checksum offload in some scenarios (e.g.
PPPoE).

- Support using SMP threads for handling packet backlog i.e. packet
processing from software interfaces and old drivers which don't use
NAPI. This helps move the processing out of the softirq jumble.

- Continue work of converting from rtnl lock to RCU protection.

Don't require rtnl lock when reading: IPv6 routing FIB, IPv6
address labels, netdev threaded NAPI sysfs files, bonding driver's
sysfs files, MPLS devconf, IPv4 FIB rules, netns IDs, tcp metrics,
TC Qdiscs, neighbor entries, ARP entries via ioctl(SIOCGARP), a lot
of the link information available via rtnetlink.

- Small optimizations from Eric to UDP wake up handling, memory
accounting, RPS/RFS implementation, TCP packet sizing etc.

- Allow direct page recycling in the bulk API used by XDP, for +2%
PPS.

- Support peek with an offset on TCP sockets.

- Add MPTCP APIs for querying last time packets were received/sent/acked
and whether MPTCP "upgrade" succeeded on a TCP socket.

- Add intra-node communication shortcut to improve SMC performance.

- Add IPv6 (and IPv{4,6}-over-IPv{4,6}) support to the GTP protocol
driver.

- Add HSR-SAN (RedBOX) mode of operation to the HSR protocol driver.

- Add reset reasons for tracing what caused a TCP reset to be sent.

- Introduce direction attribute for xfrm (IPSec) states. State can be
used either for input or output packet processing.

Things we sprinkled into general kernel code:

- Add bitmap_{read,write}(), bitmap_size(), expose BYTES_TO_BITS().

This required touch-ups and renaming of a few existing users.

- Add Endian-dependent __counted_by_{le,be} annotations.

- Make building selftests "quieter" by printing summaries like
"CC object.o" rather than full commands with all the arguments.

Netfilter:

- Use GFP_KERNEL to clone elements, to deal better with OOM
situations and avoid failures in the .commit step.

BPF:

- Add eBPF JIT for ARCv2 CPUs.

- Support attaching kprobe BPF programs through kprobe_multi link in
a session mode, meaning, a BPF program is attached to both function
entry and return, the entry program can decide if the return
program gets executed and the entry program can share u64 cookie
value with return program. "Session mode" is a common use-case for
tetragon and bpftrace.

- Add the ability to specify and retrieve BPF cookie for raw
tracepoint programs in order to ease migration from classic to raw
tracepoints.

- Add an internal-only BPF per-CPU instruction for resolving per-CPU
memory addresses and implement support in x86, ARM64 and RISC-V
JITs. This allows inlining functions which need to access per-CPU
state.

- Optimize x86 BPF JIT's emit_mov_imm64, and add support for various
atomics in bpf_arena which can be JITed as a single x86
instruction. Support BPF arena on ARM64.

- Add a new bpf_wq API for deferring events and refactor
process-context bpf_timer code to keep common code where possible.

- Harden the BPF verifier's and/or/xor value tracking.

- Introduce crypto kfuncs to let BPF programs call kernel crypto
APIs.

- Support bpf_tail_call_static() helper for BPF programs with GCC 13.

- Add bpf_preempt_{disable,enable}() kfuncs in order to allow a BPF
program to have code sections where preemption is disabled.

Driver API:

- Skip software TC processing completely if all installed rules are
marked as HW-only, instead of checking the HW-only flag rule by
rule.

- Add support for configuring PoE (Power over Ethernet), similar to
the already existing support for PoDL (Power over Data Line)
config.

- Initial bits of a queue control API, for now allowing a single
queue to be reset without disturbing packet flow to other queues.

- Common (ethtool) statistics for hardware timestamping.

Tests and tooling:

- Remove the need to create a config file to run the net forwarding
tests so that a naive "make run_tests" can exercise them.

- Define a method of writing tests which require an external endpoint
to communicate with (to send/receive data towards the test
machine). Add a few such tests.

- Create a shared code library for writing Python tests. Expose the
YAML Netlink library from tools/ to the tests for easy Netlink
access.

- Move netfilter tests under net/, extend them, separate performance
tests from correctness tests, and iron out issues found by running
them "on every commit".

- Refactor BPF selftests to use common network helpers.

- Further work filling in YAML definitions of Netlink messages for:
nftables, team driver, bonding interfaces, vlan interfaces, VF
info, TC u32 mark, TC police action.

- Teach Python YAML Netlink to decode attribute policies.

- Extend the definition of the "indexed array" construct in the specs
to cover arrays of scalars rather than just nests.

- Add hyperlinks between definitions in generated Netlink docs.

Drivers:

- Make sure unsupported flower control flags are rejected by drivers,
and make more drivers report errors directly to the application
rather than dmesg (large number of driver changes from Asbjørn
Sloth Tønnesen).

- Ethernet high-speed NICs:
- Broadcom (bnxt):
- support multiple RSS contexts and steering traffic to them
- support XDP metadata
- make page pool allocations more NUMA aware
- Intel (100G, ice, idpf):
- extract datapath code common among Intel drivers into a library
- use fewer resources in switchdev by sharing queues with the PF
- add PFCP filter support
- add Ethernet filter support
- use a spinlock instead of HW lock in PTP clock ops
- support 5 layer Tx scheduler topology
- nVidia/Mellanox:
- 800G link modes and 100G SerDes speeds
- per-queue IRQ coalescing configuration
- Marvell Octeon:
- support offloading TC packet mark action

- Ethernet NICs consumer, embedded and virtual:
- stop lying about skb->truesize in USB Ethernet drivers, it
messes up TCP memory calculations
- Google cloud vNIC:
- support changing ring size via ethtool
- support ring reset using the queue control API
- VirtIO net:
- expose flow hash from RSS to XDP
- per-queue statistics
- add selftests
- Synopsys (stmmac):
- support controllers which require an RX clock signal from the
MII bus to perform their hardware initialization
- TI:
- icssg_prueth: support ICSSG-based Ethernet on AM65x SR1.0 devices
- icssg_prueth: add SW TX / RX Coalescing based on hrtimers
- cpsw: minimal XDP support
- Renesas (ravb):
- support describing the MDIO bus
- Realtek (r8169):
- add support for RTL8168M
- Microchip Sparx5:
- matchall and flower actions mirred and redirect

- Ethernet switches:
- nVidia/Mellanox:
- improve events processing performance
- Marvell:
- add support for MV88E6250 family internal PHYs
- Microchip:
- add DCB and DSCP mapping support for KSZ switches
- vsc73xx: convert to PHYLINK
- Realtek:
- rtl8226b/rtl8221b: add C45 instances and SerDes switching

- Many driver changes related to PHYLIB and PHYLINK deprecated API
cleanup

- Ethernet PHYs:
- Add a new driver for Airoha EN8811H 2.5 Gigabit PHY.
- micrel: lan8814: add support for PPS out and external timestamp trigger

- WiFi:
- Disable Wireless Extensions (WEXT) in all Wi-Fi 7 devices
drivers. Modern devices can only be configured using nl80211.
- mac80211/cfg80211
- handle color change per link for WiFi 7 Multi-Link Operation
- Intel (iwlwifi):
- don't support puncturing in 5 GHz
- support monitor mode on passive channels
- BZ-W device support
- P2P with HE/EHT support
- re-add support for firmware API 90
- provide channel survey information for Automatic Channel Selection
- MediaTek (mt76):
- mt7921 LED control
- mt7925 EHT radiotap support
- mt7920e PCI support
- Qualcomm (ath11k):
- P2P support for QCA6390, WCN6855 and QCA2066
- support hibernation
- ieee80211-freq-limit Device Tree property support
- Qualcomm (ath12k):
- refactoring in preparation of multi-link support
- suspend and hibernation support
- ACPI support
- debugfs support, including dfs_simulate_radar support
- RealTek:
- rtw88: RTL8723CS SDIO device support
- rtw89: RTL8922AE Wi-Fi 7 PCI device support
- rtw89: complete features of new WiFi 7 chip 8922AE including
BT-coexistence and Wake-on-WLAN
- rtw89: use BIOS ACPI settings to set TX power and channels
- rtl8xxxu: enable Management Frame Protection (MFP) support

- Bluetooth:
- support for Intel BlazarI and Filmore Peak2 (BE201)
- support for MediaTek MT7921S SDIO
- initial support for Intel PCIe BT driver
- remove HCI_AMP support"

* tag 'net-next-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1827 commits)
selftests: netfilter: fix packetdrill conntrack testcase
net: gro: fix napi_gro_cb zeroed alignment
Bluetooth: btintel_pcie: Refactor and code cleanup
Bluetooth: btintel_pcie: Fix warning reported by sparse
Bluetooth: hci_core: Fix not handling hdev->le_num_of_adv_sets=1
Bluetooth: btintel: Fix compiler warning for multi_v7_defconfig config
Bluetooth: btintel_pcie: Fix compiler warnings
Bluetooth: btintel_pcie: Add *setup* function to download firmware
Bluetooth: btintel_pcie: Add support for PCIe transport
Bluetooth: btintel: Export few static functions
Bluetooth: HCI: Remove HCI_AMP support
Bluetooth: L2CAP: Fix div-by-zero in l2cap_le_flowctl_init()
Bluetooth: qca: Fix error code in qca_read_fw_build_info()
Bluetooth: hci_conn: Use __counted_by() and avoid -Wfamnae warning
Bluetooth: btintel: Add support for Filmore Peak2 (BE201)
Bluetooth: btintel: Add support for BlazarI
LE Create Connection command timeout increased to 20 secs
dt-bindings: net: bluetooth: Add MediaTek MT7921S SDIO Bluetooth
Bluetooth: compute LE flow credits based on recvbuf space
Bluetooth: hci_sync: Use cmd->num_cis instead of magic number
...

landlock: Document IOCTL support

2024-05-13T04:58:34+00:00

In the paragraph above the fallback logic, use the shorter phrasing
from the landlock(7) man page.

Signed-off-by: Günther Noack 
Link: https://lore.kernel.org/r/20240419161122.2023765-10-gnoack@google.com
[mic: Update date, and fix redundant "access"]
Signed-off-by: Mickaël Salaün

media: v4l: Add V4L2-PIX-FMT-Y14P format

2024-04-29T12:56:37+00:00

This is a packed grey-scale image format with a depth of 14 bits per
pixel. Every four consecutive samples are packed into seven bytes. Each
of the first four bytes contain the eight high order bits of the pixels,
and the three following bytes contains the six least significants bits
of each pixel, in the same order.

As the other formats only needed 5 bytes before, append two bytes in the
documentation array.

Signed-off-by: Jean-Michel Hautbois 
Reviewed-by: Laurent Pinchart 
Signed-off-by: Laurent Pinchart 
Signed-off-by: Sakari Ailus 
Signed-off-by: Hans Verkuil