Some spi controller switch the mosi line to high, whenever they are
idle. This may not be desired in all use cases. For example neopixel
leds can get confused and flicker due to misinterpreting the idle state.
Therefore, we introduce a new spi-mode bit, with which the idle behaviour
can be overwritten on a per device basis.
Signed-off-by: Boerge Struempfel <boerge.struempfel@gmail.com>
Link: https://lore.kernel.org/r/20230530141641.1155691-2-boerge.struempfel@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit adds new event to notify event of phy packet with time stamp
field.
Unlike the fw_cdev_event_request3 and fw_cdev_event_response2, the size
of new structure, fw_cdev_event_phy_packet2, is multiples of 8, thus
padding is not required to keep the same size between System V ABI for
different architectures.
It is noticeable that for the case of ping request 1394 OHCI controller
does not record the isochronous cycle at which the packet was sent for
the request subaction. Instead, it records round-trip count measured by
hardware at 42.195 MHz resolution.
Cc: kunit-dev@googlegroups.com
Link: https://lore.kernel.org/r/20230529113406.986289-12-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
This commit adds new event to notify event of response subaction with
time stamp field.
Current compiler implementation of System V ABI selects one of structure
members which has the maximum alignment size in the structure to decide
the size of structure. In the case of fw_cdev_event_request3 structure,
it is closure member which has 8 byte storage. The size of alignment for
the type of 8 byte storage differs depending on architectures; 4 byte for
i386 architecture and 8 byte for the others including x32 architecture.
It is inconvenient to device driver developer to use structure layout
which varies between architectures since the developer takes care of ioctl
compat layer. This commit adds 32 bit member for padding to keep the
size of structure as multiples of 8.
Cc: kunit-dev@googlegroups.com
Link: https://lore.kernel.org/r/20230529113406.986289-9-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
This commit adds new event to notify event of request subaction with
time stamp field.
Current compiler implementation of System V ABI selects one of structure
members which has the maximum alignment size in the structure to decide
the size of structure. In the case of fw_cdev_event_request3 structure,
it is closure member which has 8 byte storage. The size of alignment for
the type of 8 byte storage differs depending on architectures; 4 byte for
i386 architecture and 8 byte for the others including x32 architecture.
It is inconvenient to device driver developer to use structure layout
which varies between architectures since the developer takes care of ioctl
compat layer. This commit adds 32 bit member for padding to keep the
size of structure as multiples of 8.
Cc: kunit-dev@googlegroups.com
Link: https://lore.kernel.org/r/20230529113406.986289-4-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Zero-length and one-element arrays are deprecated, and we are moving
towards adopting C99 flexible-array members, instead.
Address the following warnings seen under GCC-13 and
-fstrict-flex-arrays=3 enabled:
drivers/staging/ks7010/ks_wlan_net.c:1597:50: warning: array subscript 0 is outside array bounds of ‘__u8[0]’ {aka ‘unsigned char[]’} [-Warray-bounds=]
drivers/staging/ks7010/ks_wlan_net.c:1603:61: warning: array subscript 16 is outside array bounds of ‘__u8[0]’ {aka ‘unsigned char[]’} [-Warray-bounds=]
drivers/staging/ks7010/ks_wlan_net.c:1604:61: warning: array subscript 24 is outside array bounds of ‘__u8[0]’ {aka ‘unsigned char[]’} [-Warray-bounds=]
drivers/staging/ks7010/ks_wlan_net.c:1600:61: warning: array subscript 16 is outside array bounds of ‘__u8[0]’ {aka ‘unsigned char[]’} [-Warray-bounds=]
drivers/staging/ks7010/ks_wlan_net.c:1586:50: warning: array subscript 0 is outside array bounds of ‘__u8[0]’ {aka ‘unsigned char[]’} [-Warray-bounds=]
This helps with the ongoing efforts to tighten the FORTIFY_SOURCE
routines on memcpy() and help us make progress towards globally
enabling -fstrict-flex-arrays=3 [1].
This results in no differences in binary output.
Link: https://github.com/KSPP/linux/issues/21
Link: https://github.com/KSPP/linux/issues/261
Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1]
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Daniel Borkmann says:
====================
pull-request: bpf-next 2023-05-26
We've added 54 non-merge commits during the last 10 day(s) which contain
a total of 76 files changed, 2729 insertions(+), 1003 deletions(-).
The main changes are:
1) Add the capability to destroy sockets in BPF through a new kfunc,
from Aditi Ghag.
2) Support O_PATH fds in BPF_OBJ_PIN and BPF_OBJ_GET commands,
from Andrii Nakryiko.
3) Add capability for libbpf to resize datasec maps when backed via mmap,
from JP Kobryn.
4) Move all the test kfuncs for CI out of the kernel and into bpf_testmod,
from Jiri Olsa.
5) Big batch of xsk selftest improvements to prep for multi-buffer testing,
from Magnus Karlsson.
6) Show the target_{obj,btf}_id in tracing link's fdinfo and dump it
via bpftool, from Yafang Shao.
7) Various misc BPF selftest improvements to work with upcoming LLVM 17,
from Yonghong Song.
8) Extend bpftool to specify netdevice for resolving XDP hints,
from Larysa Zaremba.
9) Document masking in shift operations for the insn set document,
from Dave Thaler.
10) Extend BPF selftests to check xdp_feature support for bond driver,
from Lorenzo Bianconi.
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (54 commits)
bpf: Fix bad unlock balance on freeze_mutex
libbpf: Ensure FD >= 3 during bpf_map__reuse_fd()
libbpf: Ensure libbpf always opens files with O_CLOEXEC
selftests/bpf: Check whether to run selftest
libbpf: Change var type in datasec resize func
bpf: drop unnecessary bpf_capable() check in BPF_MAP_FREEZE command
libbpf: Selftests for resizing datasec maps
libbpf: Add capability for resizing datasec maps
selftests/bpf: Add path_fd-based BPF_OBJ_PIN and BPF_OBJ_GET tests
libbpf: Add opts-based bpf_obj_pin() API and add support for path_fd
bpf: Support O_PATH FDs in BPF_OBJ_PIN and BPF_OBJ_GET commands
libbpf: Start v1.3 development cycle
bpf: Validate BPF object in BPF_OBJ_PIN before calling LSM
bpftool: Specify XDP Hints ifname when loading program
selftests/bpf: Add xdp_feature selftest for bond device
selftests/bpf: Test bpf_sock_destroy
selftests/bpf: Add helper to get port using getsockname
bpf: Add bpf_sock_destroy kfunc
bpf: Add kfunc filter function to 'struct btf_kfunc_id_set'
bpf: udp: Implement batching for sockets iterator
...
====================
Link: https://lore.kernel.org/r/20230526222747.17775-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Pull networking fixes from Paolo Abeni:
"Including fixes from bluetooth and bpf.
Current release - regressions:
- net: fix skb leak in __skb_tstamp_tx()
- eth: mtk_eth_soc: fix QoS on DSA MAC on non MTK_NETSYS_V2 SoCs
Current release - new code bugs:
- handshake:
- fix sock->file allocation
- fix handshake_dup() ref counting
- bluetooth:
- fix potential double free caused by hci_conn_unlink
- fix UAF in hci_conn_hash_flush
Previous releases - regressions:
- core: fix stack overflow when LRO is disabled for virtual
interfaces
- tls: fix strparser rx issues
- bpf:
- fix many sockmap/TCP related issues
- fix a memory leak in the LRU and LRU_PERCPU hash maps
- init the offload table earlier
- eth: mlx5e:
- do as little as possible in napi poll when budget is 0
- fix using eswitch mapping in nic mode
- fix deadlock in tc route query code
Previous releases - always broken:
- udplite: fix NULL pointer dereference in __sk_mem_raise_allocated()
- raw: fix output xfrm lookup wrt protocol
- smc: reset connection when trying to use SMCRv2 fails
- phy: mscc: enable VSC8501/2 RGMII RX clock
- eth: octeontx2-pf: fix TSOv6 offload
- eth: cdc_ncm: deal with too low values of dwNtbOutMaxSize"
* tag 'net-6.4-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (79 commits)
udplite: Fix NULL pointer dereference in __sk_mem_raise_allocated().
net: phy: mscc: enable VSC8501/2 RGMII RX clock
net: phy: mscc: remove unnecessary phydev locking
net: phy: mscc: add support for VSC8501
net: phy: mscc: add VSC8502 to MODULE_DEVICE_TABLE
net/handshake: Enable the SNI extension to work properly
net/handshake: Unpin sock->file if a handshake is cancelled
net/handshake: handshake_genl_notify() shouldn't ignore @flags
net/handshake: Fix uninitialized local variable
net/handshake: Fix handshake_dup() ref counting
net/handshake: Remove unneeded check from handshake_dup()
ipv6: Fix out-of-bounds access in ipv6_find_tlv()
net: ethernet: mtk_eth_soc: fix QoS on DSA MAC on non MTK_NETSYS_V2 SoCs
docs: netdev: document the existence of the mail bot
net: fix skb leak in __skb_tstamp_tx()
r8169: Use a raw_spinlock_t for the register locks.
page_pool: fix inconsistency for page_pool_ring_[un]lock()
bpf, sockmap: Test progs verifier error with latest clang
bpf, sockmap: Test FIONREAD returns correct bytes in rx buffer with drops
bpf, sockmap: Test FIONREAD returns correct bytes in rx buffer
...
Use unsigned int values annoted by "U" for u32 fields. While this is a
good practice, there doesn't appear to be a bug that this patch would fix.
The patch has been generated using the following command:
perl -i -pe 's/\([0-9]+\K <</U <</g; s/\|\s*0\K\)/U\)/' \
include/uapi/linux/media.h
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Some drivers firmwares parse by themselves slice header and need
num_delta_pocs_of_ref_rps_idx value to parse slice header
short_term_ref_pic_set().
Use one of the 4 reserved bytes to store this value without
changing the v4l2_ctrl_hevc_decode_params structure size and padding.
This value also exist in DXVA API.
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
Signed-off-by: Yunfei Dong <yunfei.dong@mediatek.com>
Reviewed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
[hverkuil: fix typo in num_delta_pocs_of_ref_rps_idx doc]
VIDIOC_ENUMINPUT documentation describes the tuner field of
struct v4l2_input as index:
Documentation/userspace-api/media/v4l/vidioc-enuminput.rst
"
* - __u32
- ``tuner``
- Capture devices can have zero or more tuners (RF demodulators).
When the ``type`` is set to ``V4L2_INPUT_TYPE_TUNER`` this is an
RF connector and this field identifies the tuner. It corresponds
to struct :c:type:`v4l2_tuner` field ``index``. For
details on tuners see :ref:`tuner`.
"
Drivers I could find also use the 'tuner' field as an index, e.g.:
drivers/media/pci/bt8xx/bttv-driver.c bttv_enum_input()
drivers/media/usb/go7007/go7007-v4l2.c vidioc_enum_input()
However, the UAPI comment claims this field is 'enum v4l2_tuner_type':
include/uapi/linux/videodev2.h
This field being 'enum v4l2_tuner_type' is unlikely as it seems to be
never used that way in drivers, and documentation confirms it. It seem
this comment got in accidentally in the commit which this patch fixes.
Fix the UAPI comment to stop confusion.
This was pointed out by Dmitry while reviewing VIDIOC_ENUMINPUT
support for strace.
Fixes: 6016af82ea ("[media] v4l2: use __u32 rather than enums in ioctl() structs")
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Use the intended pointer types for p_s32 and p_64 in the union of the
struct v4l2_ext_control.
Fixes: e77eb66342 ("videodev2.h: add p_s32 and p_s64 pointers")
Signed-off-by: Daniel Lundberg Pedersen <dlp@qtec.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Some userspace programs use st_ino as a unique object identifier, even
though inode numbers may be recycable.
This issue has been addressed for NFS export long ago using the exportfs
file handle API and the unique file handle identifiers are also exported
to userspace via name_to_handle_at(2).
fanotify also uses file handles to identify objects in events, but only
for filesystems that support NFS export.
Relax the requirement for NFS export support and allow more filesystems
to export a unique object identifier via name_to_handle_at(2) with the
flag AT_HANDLE_FID.
A file handle requested with the AT_HANDLE_FID flag, may or may not be
usable as an argument to open_by_handle_at(2).
To allow filesystems to opt-in to supporting AT_HANDLE_FID, a struct
export_operations is required, but even an empty struct is sufficient
for encoding FIDs.
Acked-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Message-Id: <20230502124817.3070545-4-amir73il@gmail.com>
Enable the upper layer protocol to specify the SNI peername. This
avoids the need for tlshd to use a DNS lookup, which can return a
hostname that doesn't match the incoming certificate's SubjectName.
Fixes: 2fd5532044 ("net/handshake: Add a kernel API for requesting a TLSv1.3 handshake")
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add a helper to convert a clause 73 advertisement to an ethtool bitmap.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Current UAPI of BPF_OBJ_PIN and BPF_OBJ_GET commands of bpf() syscall
forces users to specify pinning location as a string-based absolute or
relative (to current working directory) path. This has various
implications related to security (e.g., symlink-based attacks), forces
BPF FS to be exposed in the file system, which can cause races with
other applications.
One of the feedbacks we got from folks working with containers heavily
was that inability to use purely FD-based location specification was an
unfortunate limitation and hindrance for BPF_OBJ_PIN and BPF_OBJ_GET
commands. This patch closes this oversight, adding path_fd field to
BPF_OBJ_PIN and BPF_OBJ_GET UAPI, following conventions established by
*at() syscalls for dirfd + pathname combinations.
This now allows interesting possibilities like working with detached BPF
FS mount (e.g., to perform multiple pinnings without running a risk of
someone interfering with them), and generally making pinning/getting
more secure and not prone to any races and/or security attacks.
This is demonstrated by a selftest added in subsequent patch that takes
advantage of new mount APIs (fsopen, fsconfig, fsmount) to demonstrate
creating detached BPF FS mount, pinning, and then getting BPF map out of
it, all while never exposing this private instance of BPF FS to outside
worlds.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/bpf/20230523170013.728457-4-andrii@kernel.org
With a raw socket bound to IPPROTO_RAW (ie with hdrincl enabled), the
protocol field of the flow structure, build by raw_sendmsg() /
rawv6_sendmsg()), is set to IPPROTO_RAW. This breaks the ipsec policy
lookup when some policies are defined with a protocol in the selector.
For ipv6, the sin6_port field from 'struct sockaddr_in6' could be used to
specify the protocol. Just accept all values for IPPROTO_RAW socket.
For ipv4, the sin_port field of 'struct sockaddr_in' could not be used
without breaking backward compatibility (the value of this field was never
checked). Let's add a new kind of control message, so that the userland
could specify which protocol is used.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
CC: stable@vger.kernel.org
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Link: https://lore.kernel.org/r/20230522120820.1319391-1-nicolas.dichtel@6wind.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This is a (largish) patch set for adding the support of MIDI 2.0
functionality, mainly targeted for USB devices. MIDI 2.0 is a
complete overhaul of the 40-years old MIDI 1.0. Unlike MIDI 1.0 byte
stream, MIDI 2.0 uses packets in 32bit words for Universal MIDI Packet
(UMP) protocol. It supports both MIDI 1.0 commands for compatibility
and the extended MIDI 2.0 commands for higher resolutions and more
functions.
For supporting the UMP, the patch set extends the existing ALSA
rawmidi and sequencer interfaces, and adds the USB MIDI 2.0 support to
the standard USB-audio driver.
The rawmidi for UMP has a different device name (/dev/snd/umpC*D*) and
it reads/writes UMP packet data in 32bit CPU-native endianness. For
the old MIDI 1.0 applications, the legacy rawmidi interface is
provided, too.
As default, USB-audio driver will take the alternate setting for MIDI
2.0 interface, and the compatibility with MIDI 1.0 is provided via the
rawmidi common layer. However, user may let the driver falling back
to the old MIDI 1.0 interface by a module option, too.
A UMP-capable rawmidi device can create the corresponding ALSA
sequencer client(s) to support the UMP Endpoint and UMP Group
connections. As a nature of ALSA sequencer, arbitrary connections
between clients/ports are allowed, and the ALSA sequencer core
performs the automatic conversions for the connections between a new
UMP sequencer client and a legacy MIDI 1.0 sequencer client. It
allows the existing application to use MIDI 2.0 devices without
changes.
The MIDI-CI, which is another major extension in MIDI 2.0, isn't
covered by this patch set. It would be implemented rather in
user-space.
Roughly speaking, the first half of this patch set is for extending
the rawmidi and USB-audio, and the second half is for extending the
ALSA sequencer interface.
The patch set is based on 6.4-rc2 kernel, but all patches can be
cleanly applicable on 6.2 and 6.3 kernels, too (while 6.1 and older
kernels would need minor adjustment for uapi header changes).
The updates for alsa-lib and alsa-utils will follow shortly later.
The author thanks members of MIDI Association OS/API Working Group,
especially Andrew Mee, for great helps for the initial design and
debugging / testing the drivers.
Link: https://lore.kernel.org/r/20230523075358.9672-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Add a new filter bitmap for UMP groups for reducing the unnecessary
read/write when the client is connected to UMP EP seq port.
The new group_filter field contains the bitmap for the groups, i.e.
when the bit is set, the corresponding group is filtered out and
the messages to that group won't be delivered.
The filter bitmap consists of each bit of 1-based UMP Group number.
The bit 0 is reserved for the future use.
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230523075358.9672-37-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Add new ioctls for sequencer clients to query and set the UMP endpoint
and block information.
As a sequencer client corresponds to a UMP Endpoint, one UMP Endpoint
information can be assigned at most to a single sequencer client while
multiple UMP block infos can be assigned by passing the type with the
offset of block id (i.e. type = block_id + 1).
For the kernel client, only SNDRV_SEQ_IOCTL_GET_CLIENT_UMP_INFO is
allowed.
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230523075358.9672-35-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This patch introduces a new ALSA sequencer client for the kernel UMP
object, snd-seq-ump-client. It's a UMP version of snd-seq-midi
driver, while this driver creates a sequencer client per UMP endpoint
which contains (fixed) 16 ports.
The UMP rawmidi device is opened in APPEND mode for output, so that
multiple sequencer clients can share the same UMP endpoint, as well as
the legacy UMP rawmidi devices that are opened in APPEND mode, too.
For input, on the other hand, the incoming data is processed on the
fly in the dedicated hook, hence it doesn't open a rawmidi device.
The UMP packet group is updated upon delivery depending on the target
sequencer port (which corresponds to the actual UMP group).
Each sequencer port sets a new port type bit,
SNDRV_SEQ_PORT_TYPE_MIDI_UMP, in addition to the other standard
types for MIDI.
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230523075358.9672-33-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
A sequencer client like seq_dummy rather doesn't want to convert UMP
events but receives / sends as is. Add a new event filter flag to
suppress the automatic UMP conversion and applies accordingly.
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230523075358.9672-32-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Add yet more new filed "ump_group" to snd_seq_port_info for specifying
the associated UMP Group number for each sequencer port. This will be
referred in the upcoming automatic UMP conversion in sequencer core.
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230523075358.9672-30-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Add a new field "direction" to snd_seq_port_info for allowing a client
to tell the expected direction of the port access. A port might still
allow subscriptions for read/write (e.g. for MIDI-CI) even if the
primary usage of the port is a single direction (either input or
output only). This new "direction" field can help to indicate such
cases.
When the direction is unspecified at creating a port and the port has
either read or write capability, the corresponding direction bits are
set automatically as default.
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230523075358.9672-29-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This is an extension to ALSA sequencer infrastructure to support the
MIDI 2.0 UMP Endpoint port. It's a "catch-all" port that is supposed
to be present for each UMP Endpoint. When this port is read via
subscription, it sends any events from all ports (UMP Groups) found in
the same client.
A UMP Endpoint port can be created with the new capability bit
SNDRV_SEQ_PORT_CAP_UMP_ENDPOINT. Although the port assignment isn't
strictly defined, it should be the port number 0.
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230523075358.9672-28-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This extends the ALSA sequencer port capability bit to indicate the
"inactive" flag. When this flag is set, the port is essentially
invisible, and doesn't appear in the port query ioctls, while the
direct access and the connection to this port are still allowed. The
active/inactive state can be flipped dynamically, so that it can be
visible at any time later.
This feature is introduced basically for UMP; some UMP Groups in a UMP
Block may be unassigned, hence those are practically invisible. On
ALSA sequencer, the corresponding sequencer ports will get this new
"inactive" flag to indicate the invisible state.
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230523075358.9672-27-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Starting from this commit, we add the basic support of UMP (Universal
MIDI Packet) events on ALSA sequencer infrastructure. The biggest
change here is that, for transferring UMP packets that are up to 128
bits, we extend the data payload of ALSA sequencer event record when
the client is declared to support for the new UMP events.
A new event flag bit, SNDRV_SEQ_EVENT_UMP, is defined and it shall be
set for the UMP packet events that have the larger payload of 128
bits, defined as struct snd_seq_ump_event.
For controlling the UMP feature enablement in kernel, a new Kconfig,
CONFIG_SND_SEQ_UMP is introduced. The extended event for UMP is
available only when this Kconfig item is set. Similarly, the size of
the internal snd_seq_event_cell also increases (in 4 bytes) when the
Kconfig item is set. (But the size increase is effective only for
32bit architectures; 64bit archs already have padding there.)
Overall, when CONFIG_SND_SEQ_UMP isn't set, there is no change in the
event and cell, keeping the old sizes.
For applications that want to access the UMP packets, first of all, a
sequencer client has to declare the user-protocol to match with the
latest one via the new SNDRV_SEQ_IOCTL_USER_PVERSION; otherwise it's
treated as if a legacy client without UMP support.
Then the client can switch to the new UMP mode (MIDI 1.0 or MIDI 2.0)
with a new field, midi_version, in snd_seq_client_info. When switched
to UMP mode (midi_version = 1 or 2), the client can write the UMP
events with SNDRV_SEQ_EVENT_UMP flag. For reads, the alignment size
is changed from snd_seq_event (28 bytes) to snd_seq_ump_event (32
bytes). When a UMP sequencer event is delivered to a legacy sequencer
client, it's ignored or handled as an error.
Conceptually, ALSA sequencer client and port correspond to the UMP
Endpoint and Group, respectively; each client may have multiple ports
and each port has the fixed number (16) of channels, total up to 256
channels.
As of this commit, ALSA sequencer core just sends and receives the UMP
events as-is from/to clients. The automatic conversions between the
legacy events and the new UMP events will be implemented in a later
patch.
Along with this commit, bump the sequencer protocol version to 1.0.3.
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230523075358.9672-26-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
For the future extension of ALSA sequencer ABI, introduce a new ioctl
SNDRV_SEQ_IOCTL_USER_PVERSION. This is similar like the ioctls used
in PCM and other interfaces, for an application to specify its
supporting ABI version.
The use of this ioctl will be mandatory for the upcoming UMP support.
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230523075358.9672-25-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
It'd be convenient to have ioctls to inquiry the UMP Endpoint and UMP
Block information directly via the control API without opening the
rawmidi interface, just like SNDRV_CTL_IOCTL_RAWMIDI_INFO.
This patch extends the rawmidi ioctl handler to support those; new
ioctls, SNDRV_CTL_IOCTL_UMP_ENDPOINT_INFO and
SNDRV_CTL_IOCTL_UMP_BLOCK_INFO, return the snd_ump_endpoint and
snd_ump_block data that is specified by the device field,
respectively.
Suggested-by: Jaroslav Kysela <perex@perex.cz>
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230523075358.9672-6-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Applications may look for rawmidi devices with the ioctl
SNDRV_CTL_IOCTL_RAWMIDI_NEXT_DEVICE. Returning a UMP device from this
ioctl may confuse the existing applications that support only the
legacy rawmidi.
This patch changes the code to skip the UMP devices from the lookup
for avoiding the confusion, and introduces a new ioctl to look for the
UMP devices instead.
Along with this change, bump the CTL protocol version to 2.0.9.
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230523075358.9672-5-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This patch adds the support helpers for UMP (Universal MIDI Packet) in
ALSA core.
The basic design is that a rawmidi instance is assigned to each UMP
Endpoint. A UMP Endpoint provides a UMP stream, typically
bidirectional (but can be also uni-directional, too), which may hold
up to 16 UMP Groups, where each UMP (input/output) Group corresponds
to the traditional MIDI I/O Endpoint.
Additionally, the ALSA UMP abstraction provides the multiple UMP
Blocks that can be assigned to each UMP Endpoint. A UMP Block is a
metadata to hold the UMP Group clusters, and can represent the
functions assigned to each UMP Group. A typical implementation of UMP
Block is the Group Terminal Blocks of USB MIDI 2.0 specification.
For distinguishing from the legacy byte-stream MIDI device, a new
device "umpC*D*" will be created, instead of the standard (MIDI 1.0)
devices "midiC*D*". The UMP instance can be identified by the new
rawmidi info bit SNDRV_RAWMIDI_INFO_UMP, too.
A UMP rawmidi device reads/writes only in 4-bytes words alignment,
stored in CPU native endianness.
The transmit and receive functions take care of the input/out data
alignment, and may return zero or aligned size, and the params ioctl
may return -EINVAL when the given input/output buffer size isn't
aligned.
A few new UMP-specific ioctls are added for obtaining the new UMP
endpoint and block information.
As of this commit, no ALSA sequencer instance is attached to UMP
devices yet. They will be supported by later patches.
Along with those changes, the protocol version for rawmidi is bumped
to 2.0.3.
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230523075358.9672-4-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
I/O priorities currently only use 6-bits of the 16-bits ioprio value: the
3-upper bits are used to define up to 8 priority classes (4 of which are
valid) and the 3 lower bits of the value are used to define a priority
level for the real-time and best-effort class.
The remaining 10-bits between the I/O priority class and level are unused,
and in fact, cannot be used by the user as doing so would either result in
the value being completely ignored, or in an error returned by
ioprio_check_cap().
Use these 10-bits of an ioprio value to allow a user to specify I/O
hints. An I/O hint is defined as a 10-bitsvalue, allowing up to 1023
different hints to be specified, with the value 0 being reserved as the "no
hint" case. An I/O hint can apply to any I/O that specifies a valid
priority class other than NONE, regardless of the I/O priority level
specified.
To do so, the macros IOPRIO_PRIO_HINT() and IOPRIO_PRIO_VALUE_HINT() are
introduced in include/uapi/linux/ioprio.h to respectively allow a user to
get and set a hint in an ioprio value.
To support the ATA and SCSI command duration limits feature, 7 hints are
defined: IOPRIO_HINT_DEV_DURATION_LIMIT_1 to
IOPRIO_HINT_DEV_DURATION_LIMIT_7, allowing a user to specify which command
duration limit descriptor should be applied to the commands serving an
I/O. Specifying these hints has for now no effect whatsoever if the target
block devices do not support the command duration limits feature. However,
in the future, block I/O schedulers can be modified to optimize I/O issuing
order based on these hints, even for devices that do not support the
command duration limits feature.
Given that the 7 duration limits hints defined have no effect on any block
layer component, the actual definition of the duration limits implied by
these hints remains at the device level.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Link: https://lore.kernel.org/r/20230511011356.227789-3-nks@flawful.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The I/O priority user interface defines the 16-bits ioprio values as the
combination of the upper 3-bits for an I/O priority class and the lower
13-bits as priority data. However, the kernel only uses the lower 3-bits of
the priority data to define priority levels for the RT and BE priority
classes. The data part of an ioprio value is completely ignored for the
IDLE and NONE classes. This is enforced by checks done in
ioprio_check_cap(), which is called for all paths that allow defining an
I/O priority for I/Os: the per-context ioprio_set() system call, aio
interface and io_uring interface.
Clarify this fact in the uapi ioprio.h header file and introduce the
IOPRIO_PRIO_LEVEL_MASK and IOPRIO_PRIO_LEVEL() macros for users to define
and get priority levels in an ioprio value. The coarser macro
IOPRIO_PRIO_DATA() is retained for backward compatibility with old
applications already using it. There is no functional change introduced
with this.
In-kernel users of the IOPRIO_PRIO_DATA() macro which are explicitly
handling I/O priority data as a priority level are modified to use the new
IOPRIO_PRIO_LEVEL() macro without any functional change. Since f2fs is the
only user of this macro not explicitly using that value as a priority
level, it is left unchanged.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Link: https://lore.kernel.org/r/20230511011356.227789-2-nks@flawful.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reserve some bits in the counter config namespace which will carry the
tile id and prepare the code to handle this.
No per tile counters have been added yet.
v2:
- Fix checkpatch issues
- Use 4 bits for gt id in non-engine counters. Drop FIXME.
- Set MAX GTs to 4. Drop FIXME.
v3: (Ashutosh, Tvrtko)
- Drop BUG_ON that would never fire
- Make enable u64
- Pull in some code from next patch
v4: Set I915_PMU_MAX_GTS to 2 (Tvrtko)
v5: s/u64/u32 where needed (Ashutosh)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230519154946.3751971-7-umesh.nerlige.ramappa@intel.com
Currently copy between io request buffer(pages) and userspace buffer is
done inside ublk_map_io() or ublk_unmap_io(). This way performs very
well in case of pre-allocated userspace io buffer.
For dynamically allocated or external userspace backend io buffer,
UBLK_F_NEED_GET_DATA is added for ublk server to provide buffer by one
extra command communication for WRITE request. For READ, userspace
simply provides buffer, but can't know when the buffer is done[1].
Add UBLK_F_USER_COPY by moving io data copy out of kernel by providing
read()/write() on /dev/ublkcN, and simply let ublk server do the io
data copy. This way makes both side cleaner, the cost is that one extra
syscall for copy io data between request and backend buffer.
With UBLK_F_USER_COPY, it actually becomes possible to run per-io zero
copy now, such as, only do zero copy for big size IO, so it can be
thought as one prep patch for supporting zero copy. Meantime zero copy
still needs to expose read()/write() buffer for some corner case, such
as passthrough IO.
[1] READ buffer in UBLK_F_NEED_GET_DATA
https://lore.kernel.org/linux-block/116d8a56-0881-56d3-9bcc-78ff3e1dc4e5@linux.alibaba.com/T/#m23bd4b8634c0a054e6797063167b469949a247bb
ublksrv loop usercopy code:
https://github.com/ming1/ubdsrv/commits/usercopy
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230519065030.351216-8-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Support pread()/pwrite() on ublk char device for reading/writing request
io buffer, so data copy between io request buffer and userspace buffer
can be moved to ublk server from ublk driver. Then UBLK_F_NEED_GET_DATA
becomes not necessary, so ublk server can allocate buffer without one
extra round uring command communication for userspace to provide buffer.
IO buffer can be located by iocb->ki_pos which encodes buffer offset, io
tag and queue id info, and type of iocb->ki_pos is u64, so it is big
enough for holding reasonable queue depth, nr_queues and max io buffer
size.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230519065030.351216-7-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Various distributions are adding or are in the process of adding support
for system extensions and in the future configuration extensions through
various tools. A more detailed explanation on system and configuration
extensions can be found on the manpage which is listed below at [1].
System extension images may – dynamically at runtime — extend the /usr/
and /opt/ directory hierarchies with additional files. This is
particularly useful on immutable system images where a /usr/ and/or
/opt/ hierarchy residing on a read-only file system shall be extended
temporarily at runtime without making any persistent modifications.
When one or more system extension images are activated, their /usr/ and
/opt/ hierarchies are combined via overlayfs with the same hierarchies
of the host OS, and the host /usr/ and /opt/ overmounted with it
("merging"). When they are deactivated, the mount point is disassembled
— again revealing the unmodified original host version of the hierarchy
("unmerging"). Merging thus makes the extension's resources suddenly
appear below the /usr/ and /opt/ hierarchies as if they were included in
the base OS image itself. Unmerging makes them disappear again, leaving
in place only the files that were shipped with the base OS image itself.
System configuration images are similar but operate on directories
containing system or service configuration.
On nearly all modern distributions mount propagation plays a crucial
role and the rootfs of the OS is a shared mount in a peer group (usually
with peer group id 1):
TARGET SOURCE FSTYPE PROPAGATION MNT_ID PARENT_ID
/ / ext4 shared:1 29 1
On such systems all services and containers run in a separate mount
namespace and are pivot_root()ed into their rootfs. A separate mount
namespace is almost always used as it is the minimal isolation mechanism
services have. But usually they are even much more isolated up to the
point where they almost become indistinguishable from containers.
Mount propagation again plays a crucial role here. The rootfs of all
these services is a slave mount to the peer group of the host rootfs.
This is done so the service will receive mount propagation events from
the host when certain files or directories are updated.
In addition, the rootfs of each service, container, and sandbox is also
a shared mount in its separate peer group:
TARGET SOURCE FSTYPE PROPAGATION MNT_ID PARENT_ID
/ / ext4 shared:24 master:1 71 47
For people not too familiar with mount propagation, the master:1 means
that this is a slave mount to peer group 1. Which as one can see is the
host rootfs as indicated by shared:1 above. The shared:24 indicates that
the service rootfs is a shared mount in a separate peer group with peer
group id 24.
A service may run other services. Such nested services will also have a
rootfs mount that is a slave to the peer group of the outer service
rootfs mount.
For containers things are just slighly different. A container's rootfs
isn't a slave to the service's or host rootfs' peer group. The rootfs
mount of a container is simply a shared mount in its own peer group:
TARGET SOURCE FSTYPE PROPAGATION MNT_ID PARENT_ID
/home/ubuntu/debian-tree / ext4 shared:99 61 60
So whereas services are isolated OS components a container is treated
like a separate world and mount propagation into it is restricted to a
single well known mount that is a slave to the peer group of the shared
mount /run on the host:
TARGET SOURCE FSTYPE PROPAGATION MNT_ID PARENT_ID
/propagate/debian-tree /run/host/incoming tmpfs master:5 71 68
Here, the master:5 indicates that this mount is a slave to the peer
group with peer group id 5. This allows to propagate mounts into the
container and served as a workaround for not being able to insert mounts
into mount namespaces directly. But the new mount api does support
inserting mounts directly. For the interested reader the blogpost in [2]
might be worth reading where I explain the old and the new approach to
inserting mounts into mount namespaces.
Containers of course, can themselves be run as services. They often run
full systems themselves which means they again run services and
containers with the exact same propagation settings explained above.
The whole system is designed so that it can be easily updated, including
all services in various fine-grained ways without having to enter every
single service's mount namespace which would be prohibitively expensive.
The mount propagation layout has been carefully chosen so it is possible
to propagate updates for system extensions and configurations from the
host into all services.
The simplest model to update the whole system is to mount on top of
/usr, /opt, or /etc on the host. The new mount on /usr, /opt, or /etc
will then propagate into every service. This works cleanly the first
time. However, when the system is updated multiple times it becomes
necessary to unmount the first update on /opt, /usr, /etc and then
propagate the new update. But this means, there's an interval where the
old base system is accessible. This has to be avoided to protect against
downgrade attacks.
The vfs already exposes a mechanism to userspace whereby mounts can be
mounted beneath an existing mount. Such mounts are internally referred
to as "tucked". The patch series exposes the ability to mount beneath a
top mount through the new MOVE_MOUNT_BENEATH flag for the move_mount()
system call. This allows userspace to seamlessly upgrade mounts. After
this series the only thing that will have changed is that mounting
beneath an existing mount can be done explicitly instead of just
implicitly.
Today, there are two scenarios where a mount can be mounted beneath an
existing mount instead of on top of it:
(1) When a service or container is started in a new mount namespace and
pivot_root()s into its new rootfs. The way this is done is by
mounting the new rootfs beneath the old rootfs:
fd_newroot = open("/var/lib/machines/fedora", ...);
fd_oldroot = open("/", ...);
fchdir(fd_newroot);
pivot_root(".", ".");
After the pivot_root(".", ".") call the new rootfs is mounted
beneath the old rootfs which can then be unmounted to reveal the
underlying mount:
fchdir(fd_oldroot);
umount2(".", MNT_DETACH);
Since pivot_root() moves the caller into a new rootfs no mounts must
be propagated out of the new rootfs as a consequence of the
pivot_root() call. Thus, the mounts cannot be shared.
(2) When a mount is propagated to a mount that already has another mount
mounted on the same dentry.
The easiest example for this is to create a new mount namespace. The
following commands will create a mount namespace where the rootfs
mount / will be a slave to the peer group of the host rootfs /
mount's peer group. IOW, it will receive propagation from the host:
mount --make-shared /
unshare --mount --propagation=slave
Now a new mount on the /mnt dentry in that mount namespace is
created. (As it can be confusing it should be spelled out that the
tmpfs mount on the /mnt dentry that was just created doesn't
propagate back to the host because the rootfs mount / of the mount
namespace isn't a peer of the host rootfs.):
mount -t tmpfs tmpfs /mnt
TARGET SOURCE FSTYPE PROPAGATION
└─/mnt tmpfs tmpfs
Now another terminal in the host mount namespace can observe that
the mount indeed hasn't propagated back to into the host mount
namespace. A new mount can now be created on top of the /mnt dentry
with the rootfs mount / as its parent:
mount --bind /opt /mnt
TARGET SOURCE FSTYPE PROPAGATION
└─/mnt /dev/sda2[/opt] ext4 shared:1
The mount namespace that was created earlier can now observe that
the bind mount created on the host has propagated into it:
TARGET SOURCE FSTYPE PROPAGATION
└─/mnt /dev/sda2[/opt] ext4 master:1
└─/mnt tmpfs tmpfs
But instead of having been mounted on top of the tmpfs mount at the
/mnt dentry the /opt mount has been mounted on top of the rootfs
mount at the /mnt dentry. And the tmpfs mount has been remounted on
top of the propagated /opt mount at the /opt dentry. So in other
words, the propagated mount has been mounted beneath the preexisting
mount in that mount namespace.
Mount namespaces make this easy to illustrate but it's also easy to
mount beneath an existing mount in the same mount namespace
(The following example assumes a shared rootfs mount / with peer
group id 1):
mount --bind /opt /opt
TARGET SOURCE FSTYPE MNT_ID PARENT_ID PROPAGATION
└─/opt /dev/sda2[/opt] ext4 188 29 shared:1
If another mount is mounted on top of the /opt mount at the /opt
dentry:
mount --bind /tmp /opt
The following clunky mount tree will result:
TARGET SOURCE FSTYPE MNT_ID PARENT_ID PROPAGATION
└─/opt /dev/sda2[/tmp] ext4 405 29 shared:1
└─/opt /dev/sda2[/opt] ext4 188 405 shared:1
└─/opt /dev/sda2[/tmp] ext4 404 188 shared:1
The /tmp mount is mounted beneath the /opt mount and another copy is
mounted on top of the /opt mount. This happens because the rootfs /
and the /opt mount are shared mounts in the same peer group.
When the new /tmp mount is supposed to be mounted at the /opt dentry
then the /tmp mount first propagates to the root mount at the /opt
dentry. But there already is the /opt mount mounted at the /opt
dentry. So the old /opt mount at the /opt dentry will be mounted on
top of the new /tmp mount at the /tmp dentry, i.e. @opt->mnt_parent
is @tmp and @opt->mnt_mountpoint is /tmp (Note that @opt->mnt_root
is /opt which is what shows up as /opt under SOURCE). So again, a
mount will be mounted beneath a preexisting mount.
(Fwiw, a few iterations of mount --bind /opt /opt in a loop on a
shared rootfs is a good example of what could be referred to as
mount explosion.)
The main point is that such mounts allows userspace to umount a top
mount and reveal an underlying mount. So for example, umounting the
tmpfs mount on /mnt that was created in example (1) using mount
namespaces reveals the /opt mount which was mounted beneath it.
In (2) where a mount was mounted beneath the top mount in the same mount
namespace unmounting the top mount would unmount both the top mount and
the mount beneath. In the process the original mount would be remounted
on top of the rootfs mount / at the /opt dentry again.
This again, is a result of mount propagation only this time it's umount
propagation. However, this can be avoided by simply making the parent
mount / of the @opt mount a private or slave mount. Then the top mount
and the original mount can be unmounted to reveal the mount beneath.
These two examples are fairly arcane and are merely added to make it
clear how mount propagation has effects on current and future features.
More common use-cases will just be things like:
mount -t btrfs /dev/sdA /mnt
mount -t xfs /dev/sdB --beneath /mnt
umount /mnt
after which we'll have updated from a btrfs filesystem to a xfs
filesystem without ever revealing the underlying mountpoint.
The crux is that the proposed mechanism already exists and that it is so
powerful as to cover cases where mounts are supposed to be updated with
new versions. Crucially, it offers an important flexibility. Namely that
updates to a system may either be forced or can be delayed and the
umount of the top mount be left to a service if it is a cooperative one.
This adds a new flag to move_mount() that allows to explicitly move a
beneath the top mount adhering to the following semantics:
* Mounts cannot be mounted beneath the rootfs. This restriction
encompasses the rootfs but also chroots via chroot() and pivot_root().
To mount a mount beneath the rootfs or a chroot, pivot_root() can be
used as illustrated above.
* The source mount must be a private mount to force the kernel to
allocate a new, unused peer group id. This isn't a required
restriction but a voluntary one. It avoids repeating a semantical
quirk that already exists today. If bind mounts which already have a
peer group id are inserted into mount trees that have the same peer
group id this can cause a lot of mount propagation events to be
generated (For example, consider running mount --bind /opt /opt in a
loop where the parent mount is a shared mount.).
* Avoid getting rid of the top mount in the kernel. Cooperative services
need to be able to unmount the top mount themselves.
This also avoids a good deal of additional complexity. The umount
would have to be propagated which would be another rather expensive
operation. So namespace_lock() and lock_mount_hash() would potentially
have to be held for a long time for both a mount and umount
propagation. That should be avoided.
* The path to mount beneath must be mounted and attached.
* The top mount and its parent must be in the caller's mount namespace
and the caller must be able to mount in that mount namespace.
* The caller must be able to unmount the top mount to prove that they
could reveal the underlying mount.
* The propagation tree is calculated based on the destination mount's
parent mount and the destination mount's mountpoint on the parent
mount. Of course, if the parent of the destination mount and the
destination mount are shared mounts in the same peer group and the
mountpoint of the new mount to be mounted is a subdir of their
->mnt_root then both will receive a mount of /opt. That's probably
easier to understand with an example. Assuming a standard shared
rootfs /:
mount --bind /opt /opt
mount --bind /tmp /opt
will cause the same mount tree as:
mount --bind /opt /opt
mount --beneath /tmp /opt
because both / and /opt are shared mounts/peers in the same peer
group and the /opt dentry is a subdirectory of both the parent's and
the child's ->mnt_root. If a mount tree like that is created it almost
always is an accident or abuse of mount propagation. Realistically
what most people probably mean in this scenarios is:
mount --bind /opt /opt
mount --make-private /opt
mount --make-shared /opt
This forces the allocation of a new separate peer group for the /opt
mount. Aferwards a mount --bind or mount --beneath actually makes
sense as the / and /opt mount belong to different peer groups. Before
that it's likely just confusion about what the user wanted to achieve.
* Refuse MOVE_MOUNT_BENEATH if:
(1) the @mnt_from has been overmounted in between path resolution and
acquiring @namespace_sem when locking @mnt_to. This avoids the
proliferation of shadow mounts.
(2) if @to_mnt is moved to a different mountpoint while acquiring
@namespace_sem to lock @to_mnt.
(3) if @to_mnt is unmounted while acquiring @namespace_sem to lock
@to_mnt.
(4) if the parent of the target mount propagates to the target mount
at the same mountpoint.
This would mean mounting @mnt_from on @mnt_to->mnt_parent and then
propagating a copy @c of @mnt_from onto @mnt_to. This defeats the
whole purpose of mounting @mnt_from beneath @mnt_to.
(5) if the parent mount @mnt_to->mnt_parent propagates to @mnt_from at
the same mountpoint.
If @mnt_to->mnt_parent propagates to @mnt_from this would mean
propagating a copy @c of @mnt_from on top of @mnt_from. Afterwards
@mnt_from would be mounted on top of @mnt_to->mnt_parent and
@mnt_to would be unmounted from @mnt->mnt_parent and remounted on
@mnt_from. But since @c is already mounted on @mnt_from, @mnt_to
would ultimately be remounted on top of @c. Afterwards, @mnt_from
would be covered by a copy @c of @mnt_from and @c would be covered
by @mnt_from itself. This defeats the whole purpose of mounting
@mnt_from beneath @mnt_to.
Cases (1) to (3) are required as they deal with races that would cause
bugs or unexpected behavior for users. Cases (4) and (5) refuse
semantical quirks that would not be a bug but would cause weird mount
trees to be created. While they can already be created via other means
(mount --bind /opt /opt x n) there's no reason to repeat past mistakes
in new features.
Link: https://man7.org/linux/man-pages/man8/systemd-sysext.8.html [1]
Link: https://brauner.io/2023/02/28/mounting-into-mount-namespaces.html [2]
Link: https://github.com/flatcar/sysext-bakery
Link: https://fedoraproject.org/wiki/Changes/Unified_Kernel_Support_Phase_1
Link: https://fedoraproject.org/wiki/Changes/Unified_Kernel_Support_Phase_2
Link: https://github.com/systemd/systemd/pull/26013
Reviewed-by: Seth Forshee (DigitalOcean) <sforshee@kernel.org>
Message-Id: <20230202-fs-move-mount-replace-v4-4-98f3d80d7eaa@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
The xt_dccp iptables module supports the matching of DCCP packets based
on the presence or absence of DCCP options. Extend nft_exthdr to add
this functionality to nftables.
Link: https://bugzilla.netfilter.org/show_bug.cgi?id=930
Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Florian Westphal <fw@strlen.de>
With IORING_REGISTER_USE_REGISTERED_RING, an application can register
the ring fd and use it via registered index rather than installed fd.
This allows using a registered ring for everything *except* the initial
mmap.
With IORING_SETUP_NO_MMAP, io_uring_setup uses buffers allocated by the
user, rather than requiring a subsequent mmap.
The combination of the two allows a user to operate *entirely* via a
registered ring fd, making it unnecessary to ever install the fd in the
first place. So, add a flag IORING_SETUP_REGISTERED_FD_ONLY to make
io_uring_setup register the fd and return a registered index, without
installing the fd.
This allows an application to avoid touching the fd table at all, and
allows a library to never even momentarily install a file descriptor.
This splits out an io_ring_add_registered_file helper from
io_ring_add_registered_fd, for use by io_uring_setup.
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Link: https://lore.kernel.org/r/bc8f431bada371c183b95a83399628b605e978a3.1682699803.git.josh@joshtriplett.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Currently io_uring applications must call mmap(2) twice to map the rings
themselves, and the sqes array. This works fine, but it does not support
using huge pages to back the rings/sqes.
Provide a way for the application to pass in pre-allocated memory for
the rings/sqes, which can then suitably be allocated from shmfs or
via mmap to get huge page support.
Particularly for larger rings, this reduces the TLBs needed.
If an application wishes to take advantage of that, it must pre-allocate
the memory needed for the sq/cq ring, and the sqes. The former must
be passed in via the io_uring_params->cq_off.user_data field, while the
latter is passed in via the io_uring_params->sq_off.user_data field. Then
it must set IORING_SETUP_NO_MMAP in the io_uring_params->flags field,
and io_uring will then map the existing memory into the kernel for shared
use. The application must not call mmap(2) to map rings as it otherwise
would have, that will now fail with -EINVAL if this setup flag was used.
The pages used for the rings and sqes must be contigious. The intent here
is clearly that huge pages should be used, otherwise the normal setup
procedure works fine as-is. The application may use one huge page for
both the rings and sqes.
Outside of those initialization changes, everything works like it did
before.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Fractional multiplication with the maximal value 2^31-1 causes some tiny
distortion. Instead, we want to multiply with the full 2^31. The catch
is of course that this cannot be represented in the DSP's signed 32 bit
registers.
One way to deal with this is to encode 1.0 as a negative number and
special-case it. As a matter of fact, the SbLive! code path already
contained such code, though the controls never actually exercised it.
A more efficient approach is to use negative values, which actually
extend to -2^31. Accordingly, for all the volume adjustments we now use
the MAC1 instruction which negates the X operand.
The range of the controls in highres mode is extended downwards, so -1
is the new zero/mute. At maximal excursion, real zero is not mute any
more, but I don't think anyone will notice this behavior change. ;-)
That also required making the min/max/values in the control structs
signed. This technically changes the user space interface, but it seems
implausible that someone would notice - the numbers were actually
treated as if they were signed anyway (and in the actual mixer iface
they _are_). And without this change, the min value didn't even make
sense in the first place (and no-one noticed, because it was always 0).
Tested-by: Jonathan Dowland <jon@dow.land>
Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Link: https://lore.kernel.org/r/20230514170323.3408834-7-oswald.buddenhagen@gmx.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
