linux-stable.git/Documentation/userspace-api/ioctl, 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)

ntsync: Introduce NTSYNC_IOC_CREATE_SEM.

2024-04-11T13:34:38+00:00

This corresponds to the NT syscall NtCreateSemaphore().

Semaphores are one of three types of object to be implemented in this driver,
the others being mutexes and events.

An NT semaphore contains a 32-bit counter, and is signaled and can be acquired
when the counter is nonzero. The counter has a maximum value which is specified
at creation time. The initial value of the semaphore is also specified at
creation time. There are no restrictions on the maximum and initial value.

Each object is exposed as an file, to which any number of fds may be opened.
When all fds are closed, the object is deleted.

Objects hold a pointer to the ntsync_device that created them. The device's
reference count is driven by struct file.

Signed-off-by: Elizabeth Figura 
Link: https://lore.kernel.org/r/20240329000621.148791-3-zfigura@codeweavers.com
Signed-off-by: Greg Kroah-Hartman

Merge tag 'net-next-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

2024-03-13T00:44:08+00:00

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

- Large effort by Eric to lower rtnl_lock pressure and remove locks:

- Make commonly used parts of rtnetlink (address, route dumps
etc) lockless, protected by RCU instead of rtnl_lock.

- Add a netns exit callback which already holds rtnl_lock,
allowing netns exit to take rtnl_lock once in the core instead
of once for each driver / callback.

- Remove locks / serialization in the socket diag interface.

- Remove 6 calls to synchronize_rcu() while holding rtnl_lock.

- Remove the dev_base_lock, depend on RCU where necessary.

- Support busy polling on a per-epoll context basis. Poll length and
budget parameters can be set independently of system defaults.

- Introduce struct net_hotdata, to make sure read-mostly global
config variables fit in as few cache lines as possible.

- Add optional per-nexthop statistics to ease monitoring / debug of
ECMP imbalance problems.

- Support TCP_NOTSENT_LOWAT in MPTCP.

- Ensure that IPv6 temporary addresses' preferred lifetimes are long
enough, compared to other configured lifetimes, and at least 2 sec.

- Support forwarding of ICMP Error messages in IPSec, per RFC 4301.

- Add support for the independent control state machine for bonding
per IEEE 802.1AX-2008 5.4.15 in addition to the existing coupled
control state machine.

- Add "network ID" to MCTP socket APIs to support hosts with multiple
disjoint MCTP networks.

- Re-use the mono_delivery_time skbuff bit for packets which user
space wants to be sent at a specified time. Maintain the timing
information while traversing veth links, bridge etc.

- Take advantage of MSG_SPLICE_PAGES for RxRPC DATA and ACK packets.

- Simplify many places iterating over netdevs by using an xarray
instead of a hash table walk (hash table remains in place, for use
on fastpaths).

- Speed up scanning for expired routes by keeping a dedicated list.

- Speed up "generic" XDP by trying harder to avoid large allocations.

- Support attaching arbitrary metadata to netconsole messages.

Things we sprinkled into general kernel code:

- Enforce VM_IOREMAP flag and range in ioremap_page_range and
introduce VM_SPARSE kind and vm_area_[un]map_pages (used by
bpf_arena).

- Rework selftest harness to enable the use of the full range of ksft
exit code (pass, fail, skip, xfail, xpass).

Netfilter:

- Allow userspace to define a table that is exclusively owned by a
daemon (via netlink socket aliveness) without auto-removing this
table when the userspace program exits. Such table gets marked as
orphaned and a restarting management daemon can re-attach/regain
ownership.

- Speed up element insertions to nftables' concatenated-ranges set
type. Compact a few related data structures.

BPF:

- Add BPF token support for delegating a subset of BPF subsystem
functionality from privileged system-wide daemons such as systemd
through special mount options for userns-bound BPF fs to a trusted
& unprivileged application.

- Introduce bpf_arena which is sparse shared memory region between
BPF program and user space where structures inside the arena can
have pointers to other areas of the arena, and pointers work
seamlessly for both user-space programs and BPF programs.

- Introduce may_goto instruction that is a contract between the
verifier and the program. The verifier allows the program to loop
assuming it's behaving well, but reserves the right to terminate
it.

- Extend the BPF verifier to enable static subprog calls in spin lock
critical sections.

- Support registration of struct_ops types from modules which helps
projects like fuse-bpf that seeks to implement a new struct_ops
type.

- Add support for retrieval of cookies for perf/kprobe multi links.

- Support arbitrary TCP SYN cookie generation / validation in the TC
layer with BPF to allow creating SYN flood handling in BPF
firewalls.

- Add code generation to inline the bpf_kptr_xchg() helper which
improves performance when stashing/popping the allocated BPF
objects.

Wireless:

- Add SPP (signaling and payload protected) AMSDU support.

- Support wider bandwidth OFDMA, as required for EHT operation.

Driver API:

- Major overhaul of the Energy Efficient Ethernet internals to
support new link modes (2.5GE, 5GE), share more code between
drivers (especially those using phylib), and encourage more
uniform behavior. Convert and clean up drivers.

- Define an API for querying per netdev queue statistics from
drivers.

- IPSec: account in global stats for fully offloaded sessions.

- Create a concept of Ethernet PHY Packages at the Device Tree level,
to allow parameterizing the existing PHY package code.

- Enable Rx hashing (RSS) on GTP protocol fields.

Misc:

- Improvements and refactoring all over networking selftests.

- Create uniform module aliases for TC classifiers, actions, and
packet schedulers to simplify creating modprobe policies.

- Address all missing MODULE_DESCRIPTION() warnings in networking.

- Extend the Netlink descriptions in YAML to cover message
encapsulation or "Netlink polymorphism", where interpretation of
nested attributes depends on link type, classifier type or some
other "class type".

Drivers:

- Ethernet high-speed NICs:
- Add a new driver for Marvell's Octeon PCI Endpoint NIC VF.
- Intel (100G, ice, idpf):
- support E825-C devices
- nVidia/Mellanox:
- support devices with one port and multiple PCIe links
- Broadcom (bnxt):
- support n-tuple filters
- support configuring the RSS key
- Wangxun (ngbe/txgbe):
- implement irq_domain for TXGBE's sub-interrupts
- Pensando/AMD:
- support XDP
- optimize queue submission and wakeup handling (+17% bps)
- optimize struct layout, saving 28% of memory on queues

- Ethernet NICs embedded and virtual:
- Google cloud vNIC:
- refactor driver to perform memory allocations for new queue
config before stopping and freeing the old queue memory
- Synopsys (stmmac):
- obey queueMaxSDU and implement counters required by 802.1Qbv
- Renesas (ravb):
- support packet checksum offload
- suspend to RAM and runtime PM support

- Ethernet switches:
- nVidia/Mellanox:
- support for nexthop group statistics
- Microchip:
- ksz8: implement PHY loopback
- add support for KSZ8567, a 7-port 10/100Mbps switch

- PTP:
- New driver for RENESAS FemtoClock3 Wireless clock generator.
- Support OCP PTP cards designed and built by Adva.

- CAN:
- Support recvmsg() flags for own, local and remote traffic on CAN
BCM sockets.
- Support for esd GmbH PCIe/402 CAN device family.
- m_can:
- Rx/Tx submission coalescing
- wake on frame Rx

- WiFi:
- Intel (iwlwifi):
- enable signaling and payload protected A-MSDUs
- support wider-bandwidth OFDMA
- support for new devices
- bump FW API to 89 for AX devices; 90 for BZ/SC devices
- MediaTek (mt76):
- mt7915: newer ADIE version support
- mt7925: radio temperature sensor support
- Qualcomm (ath11k):
- support 6 GHz station power modes: Low Power Indoor (LPI),
Standard Power) SP and Very Low Power (VLP)
- QCA6390 & WCN6855: support 2 concurrent station interfaces
- QCA2066 support
- Qualcomm (ath12k):
- refactoring in preparation for Multi-Link Operation (MLO)
support
- 1024 Block Ack window size support
- firmware-2.bin support
- support having multiple identical PCI devices (firmware needs
to have ATH12K_FW_FEATURE_MULTI_QRTR_ID)
- QCN9274: support split-PHY devices
- WCN7850: enable Power Save Mode in station mode
- WCN7850: P2P support
- RealTek:
- rtw88: support for more rtw8811cu and rtw8821cu devices
- rtw89: support SCAN_RANDOM_SN and SET_SCAN_DWELL
- rtlwifi: speed up USB firmware initialization
- rtwl8xxxu:
- RTL8188F: concurrent interface support
- Channel Switch Announcement (CSA) support in AP mode
- Broadcom (brcmfmac):
- per-vendor feature support
- per-vendor SAE password setup
- DMI nvram filename quirk for ACEPC W5 Pro"

* tag 'net-next-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2255 commits)
nexthop: Fix splat with CONFIG_DEBUG_PREEMPT=y
nexthop: Fix out-of-bounds access during attribute validation
nexthop: Only parse NHA_OP_FLAGS for dump messages that require it
nexthop: Only parse NHA_OP_FLAGS for get messages that require it
bpf: move sleepable flag from bpf_prog_aux to bpf_prog
bpf: hardcode BPF_PROG_PACK_SIZE to 2MB * num_possible_nodes()
selftests/bpf: Add kprobe multi triggering benchmarks
ptp: Move from simple ida to xarray
vxlan: Remove generic .ndo_get_stats64
vxlan: Do not alloc tstats manually
devlink: Add comments to use netlink gen tool
nfp: flower: handle acti_netdevs allocation failure
net/packet: Add getsockopt support for PACKET_COPY_THRESH
net/netlink: Add getsockopt support for NETLINK_LISTEN_ALL_NSID
selftests/bpf: Add bpf_arena_htab test.
selftests/bpf: Add bpf_arena_list test.
selftests/bpf: Add unit tests for bpf_arena_alloc/free_pages
bpf: Add helper macro bpf_addr_space_cast()
libbpf: Recognize __arena global variables.
bpftool: Recognize arena map type
...

eventpoll: Add epoll ioctl for epoll_params

2024-02-14T11:01:01+00:00

Add an ioctl for getting and setting epoll_params. User programs can use
this ioctl to get and set the busy poll usec time, packet budget, and
prefer busy poll params for a specific epoll context.

Parameters are limited:
  - busy_poll_usecs is limited to <= s32_max
  - busy_poll_budget is limited to <= NAPI_POLL_WEIGHT by unprivileged
    users (!capable(CAP_NET_ADMIN))
  - prefer_busy_poll must be 0 or 1
  - __pad must be 0

Signed-off-by: Joe Damato 
Acked-by: Stanislav Fomichev 
Reviewed-by: Jiri Slaby 
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller

fs: FS_IOC_GETUUID

2024-02-08T20:20:11+00:00

Add a new generic ioctls for querying the filesystem UUID.

These are lifted versions of the ext4 ioctls, with one change: we're not
using a flexible array member, because UUIDs will never be more than 16
bytes.

This patch adds a generic implementation of FS_IOC_GETFSUUID, which
reads from super_block->s_uuid. We're not lifting SETFSUUID from ext4 -
that can be done on offline filesystems by the people who need it,
trying to do it online is just asking for too much trouble.

Cc: Christian Brauner 
Cc: Jan Kara 
Cc: Dave Chinner 
Cc: Darrick J. Wong 
Cc: Theodore Ts'o 
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Kent Overstreet 
Link: https://lore.kernel.org/r/20240207025624.1019754-4-kent.overstreet@linux.dev
Signed-off-by: Christian Brauner

fbdev/intelfb: Remove driver

2024-01-12T11:38:37+00:00

From looking at the PCI IDs, every device supported by intelfb is
also supported by i915. Anyone still using intelfb should please
move on to i915, which does everything intelfb does but better.

Removing intelfb is motivated by the driver's excessive use of the
global screen_info state. The state belongs to architecture and
firmware code; device drivers should not attempt to access it. But
fixing intelfb would require a significant change in the driver's
probing logic. As intelfb has been obsolete for nearly 2 decades,
it is probably not worth the effort. Let's just remove it. Also
remove the related documentation.

Signed-off-by: Thomas Zimmermann 
Acked-by: Maik Broemme 
Signed-off-by: Helge Deller

powerpc/pseries/papr-sysparm: Expose character device to user space

2023-12-13T10:38:21+00:00

Until now the papr_sysparm APIs have been kernel-internal. But user
space needs access to PAPR system parameters too. The only method
available to user space today to get or set system parameters is using
sys_rtas() and /dev/mem to pass RTAS-addressable buffers between user
space and firmware. This is incompatible with lockdown and should be
deprecated.

So provide an alternative ABI to user space in the form of a
/dev/papr-sysparm character device with just two ioctl commands (get
and set). The data payloads involved are small enough to fit in the
ioctl argument buffer, making the code relatively simple.

Exposing the system parameters through sysfs has been considered but
it would be too awkward:

* The kernel currently does not have to contain an exhaustive list of
  defined system parameters. This is a convenient property to maintain
  because we don't have to update the kernel whenever a new parameter
  is added to PAPR. Exporting a named attribute in sysfs for each
  parameter would negate this.

* Some system parameters are text-based and some are not.

* Retrieval of at least one system parameter requires input data,
  which a simple read-oriented interface can't support.

Signed-off-by: Nathan Lynch 
Signed-off-by: Michael Ellerman 
Link: https://msgid.link/20231212-papr-sys_rtas-vs-lockdown-v6-11-e9eafd0c8c6c@linux.ibm.com

powerpc/pseries: Add papr-vpd character driver for VPD retrieval

2023-12-13T10:38:21+00:00

PowerVM LPARs may retrieve Vital Product Data (VPD) for system
components using the ibm,get-vpd RTAS function.

We can expose this to user space with a /dev/papr-vpd character
device, where the programming model is:

  struct papr_location_code plc = { .str = "", }; /* obtain all VPD */
  int devfd = open("/dev/papr-vpd", O_RDONLY);
  int vpdfd = ioctl(devfd, PAPR_VPD_CREATE_HANDLE, &plc);
  size_t size = lseek(vpdfd, 0, SEEK_END);
  char *buf = malloc(size);
  pread(devfd, buf, size, 0);

When a file descriptor is obtained from ioctl(PAPR_VPD_CREATE_HANDLE),
the file contains the result of a complete ibm,get-vpd sequence. The
file contents are immutable from the POV of user space. To get a new
view of the VPD, the client must create a new handle.

This design choice insulates user space from most of the complexities
that ibm,get-vpd brings:

* ibm,get-vpd must be called more than once to obtain complete
  results.

* Only one ibm,get-vpd call sequence should be in progress at a time;
  interleaved sequences will disrupt each other. Callers must have a
  protocol for serializing their use of the function.

* A call sequence in progress may receive a "VPD changed, try again"
  status, requiring the client to abandon the sequence and start
  over.

The memory required for the VPD buffers seems acceptable, around 20KB
for all VPD on one of my systems. And the value of the
/rtas/ibm,vpd-size DT property (the estimated maximum size of VPD) is
consistently 300KB across various systems I've checked.

I've implemented support for this new ABI in the rtas_get_vpd()
function in librtas, which the vpdupdate command currently uses to
populate its VPD database. I've verified that an unmodified vpdupdate
binary generates an identical database when using a librtas.so that
prefers the new ABI.

Along with the papr-vpd.h header exposed to user space, this
introduces a common papr-miscdev.h uapi header to share a base ioctl
ID with similar drivers to come.

Tested-by: Michal Suchánek 
Signed-off-by: Nathan Lynch 
Signed-off-by: Michael Ellerman 
Link: https://msgid.link/20231212-papr-sys_rtas-vs-lockdown-v6-9-e9eafd0c8c6c@linux.ibm.com

Documentation: Add TI TPS6594 PFSM

2023-06-15T11:41:53+00:00

This patch adds documentation for the TPS6594 PFSM driver.

The PFSM controls the operational states of the TPS6594 PMIC.
Depending on the operational mode, some power domain networks
remain energized while others can be off.

Signed-off-by: Julien Panis 
Message-ID: <20230511095126.105104-6-jpanis@baylibre.com>
Signed-off-by: Greg Kroah-Hartman

cifs: correct references in Documentation to old fs/cifs path

2023-05-24T21:29:21+00:00

The fs/cifs directory has moved to fs/smb/client, correct mentions
of this in Documentation and comments.

Acked-by: Namjae Jeon 
Signed-off-by: Steve French