The ssi_waketest() function definition causes a 'make W=1' warning
because the declaration is hidden away in ssi_protocol.c:
drivers/hsi/controllers/omap_ssi_core.c:147:6: error: no previous prototype for 'ssi_waketest'
Move it into a header file instead.
Fixes: dc7bf5d718 ("HSI: Introduce driver for SSI Protocol")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Pull USB / Thunderbolt fixes from Greg KH:
"Here are some USB fixes for 6.4-rc3, as well as a driver core fix that
resolves a memory leak that shows up in USB devices easier than other
subsystems.
Included in here are:
- driver core memory leak as reported and tested by syzbot and
developers
- dwc3 driver fixes for reported problems
- xhci driver fixes for reported problems
- USB gadget driver reverts to resolve regressions
- usbtmc driver fix for syzbot reported problem
- thunderbolt driver fixes for reported issues
- other small USB fixes
All of these, except for the driver core fix, have been in linux-next
with no reported problems. The driver core fix was tested and verified
to solve the issue by syzbot and the original reporter"
* tag 'usb-6.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
driver core: class: properly reference count class_dev_iter()
xhci: Fix incorrect tracking of free space on transfer rings
xhci-pci: Only run d3cold avoidance quirk for s2idle
usb-storage: fix deadlock when a scsi command timeouts more than once
usb: dwc3: fix a test for error in dwc3_core_init()
usb: typec: tps6598x: Fix fault at module removal
usb: gadget: u_ether: Fix host MAC address case
usb: typec: altmodes/displayport: fix pin_assignment_show
Revert "usb: gadget: udc: core: Invoke usb_gadget_connect only when started"
Revert "usb: gadget: udc: core: Prevent redundant calls to pullup"
usb: gadget: drop superfluous ':' in doc string
usb: dwc3: debugfs: Resume dwc3 before accessing registers
USB: UHCI: adjust zhaoxin UHCI controllers OverCurrent bit value
usb: dwc3: fix gadget mode suspend interrupt handler issue
usb: dwc3: gadget: Improve dwc3_gadget_suspend() and dwc3_gadget_resume()
USB: usbtmc: Fix direction for 0-length ioctl control messages
thunderbolt: Clear registers properly when auto clear isn't in use
Pull block fixes from Jens Axboe:
- NVMe pull request via Keith:
- More device quirks (Sagi, Hristo, Adrian, Daniel)
- Controller delete race (Maurizo)
- Multipath cleanup fix (Christoph)
- Deny writeable mmap mapping on a readonly block device (Loic)
- Kill unused define that got introduced by accident (Christoph)
- Error handling fix for s390 dasd (Stefan)
- ublk locking fix (Ming)
* tag 'block-6.4-2023-05-20' of git://git.kernel.dk/linux:
block: remove NFL4_UFLG_MASK
block: Deny writable memory mapping if block is read-only
s390/dasd: fix command reject error on ESE devices
nvme-pci: Add quirk for Teamgroup MP33 SSD
ublk: fix AB-BA lockdep warning
nvme: do not let the user delete a ctrl before a complete initialization
nvme-multipath: don't call blk_mark_disk_dead in nvme_mpath_remove_disk
nvme-pci: clamp max_hw_sectors based on DMA optimized limitation
nvme-pci: add quirk for missing secondary temperature thresholds
nvme-pci: add NVME_QUIRK_BOGUS_NID for HS-SSD-FUTURE 2048G
Instead of separate voices, we now allocate non-interleaved channels,
which may in turn contain two interleaved voices each. The higher-level
code keeps only one pointer per channel. The channels are not allocated
in one block any more, as there is no reason to do that. As a
consequence of that, and because it is cleaner regardless, we now let
the allocator store these pointers at a specified location, rather than
returning only the first one and having the calling code deduce the
remaining ones.
Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Link: https://lore.kernel.org/r/20230518140947.3725394-8-oswald.buddenhagen@gmx.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Luiz Augusto von Dentz says:
====================
bluetooth pull request for net:
- Fix compiler warnings on btnxpuart
- Fix potential double free on hci_conn_unlink
- Fix UAF on hci_conn_hash_flush
* tag 'for-net-2023-05-19' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth:
Bluetooth: btnxpuart: Fix compiler warnings
Bluetooth: Unlink CISes when LE disconnects in hci_conn_del
Bluetooth: Fix UAF in hci_conn_hash_flush again
Bluetooth: Refcnt drop must be placed last in hci_conn_unlink
Bluetooth: Fix potential double free caused by hci_conn_unlink
====================
Link: https://lore.kernel.org/r/20230519233056.2024340-1-luiz.dentz@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When the virtual interface's feature is updated, it synchronizes the
updated feature for its own lower interface.
This propagation logic should be worked as the iteration, not recursively.
But it works recursively due to the netdev notification unexpectedly.
This problem occurs when it disables LRO only for the team and bonding
interface type.
team0
|
+------+------+-----+-----+
| | | | |
team1 team2 team3 ... team200
If team0's LRO feature is updated, it generates the NETDEV_FEAT_CHANGE
event to its own lower interfaces(team1 ~ team200).
It is worked by netdev_sync_lower_features().
So, the NETDEV_FEAT_CHANGE notification logic of each lower interface
work iteratively.
But generated NETDEV_FEAT_CHANGE event is also sent to the upper
interface too.
upper interface(team0) generates the NETDEV_FEAT_CHANGE event for its own
lower interfaces again.
lower and upper interfaces receive this event and generate this
event again and again.
So, the stack overflow occurs.
But it is not the infinite loop issue.
Because the netdev_sync_lower_features() updates features before
generating the NETDEV_FEAT_CHANGE event.
Already synchronized lower interfaces skip notification logic.
So, it is just the problem that iteration logic is changed to the
recursive unexpectedly due to the notification mechanism.
Reproducer:
ip link add team0 type team
ethtool -K team0 lro on
for i in {1..200}
do
ip link add team$i master team0 type team
ethtool -K team$i lro on
done
ethtool -K team0 lro off
In order to fix it, the notifier_ctx member of bonding/team is introduced.
Reported-by: syzbot+60748c96cf5c6df8e581@syzkaller.appspotmail.com
Fixes: fd867d51f8 ("net/core: generic support for disabling netdev features down stack")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://lore.kernel.org/r/20230517143010.3596250-1-ap420073@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit adds the ability to filter kfuncs to certain BPF program
types. This is required to limit bpf_sock_destroy kfunc implemented in
follow-up commits to programs with attach type 'BPF_TRACE_ITER'.
The commit adds a callback filter to 'struct btf_kfunc_id_set'. The
filter has access to the `bpf_prog` construct including its properties
such as `expected_attached_type`.
Signed-off-by: Aditi Ghag <aditi.ghag@isovalent.com>
Link: https://lore.kernel.org/r/20230519225157.760788-7-aditi.ghag@isovalent.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
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>
Currently both requeues of commands that were already sent to the driver
and flush commands submitted from the flush state machine share the same
requeue_list struct request_queue, despite requeues doing head
insertions and flushes not. Switch to using two separate lists instead.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20230519044050.107790-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Send write requests issued by the flush state machine through the normal
I/O submission path including the I/O scheduler (if present) so that I/O
scheduler policies are applied to writes with the FUA flag set.
Separate the I/O scheduler members from the flush members in struct
request since now a request may pass through both an I/O scheduler
and the flush machinery.
Note that the actual flush requests, which have no bio attached to the
request still bypass the I/O schedulers.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
[hch: rebased]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20230519044050.107790-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull SCSI fixes from James Bottomley:
"Six small fixes.
Four in drivers and the two core changes should be read together as a
correction to a prior iorequest_cnt fix that exposed us to a potential
use after free"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
scsi: core: Decrease scsi_device's iorequest_cnt if dispatch failed
scsi: Revert "scsi: core: Do not increase scsi_device's iorequest_cnt if dispatch failed"
scsi: storvsc: Don't pass unused PFNs to Hyper-V host
scsi: ufs: core: Fix MCQ nr_hw_queues
scsi: ufs: core: Rename symbol sizeof_utp_transfer_cmd_desc()
scsi: ufs: core: Fix MCQ tag calculation
Commit 06149746e7 ("Bluetooth: hci_conn: Add support for linking
multiple hcon") reintroduced a previously fixed bug [1] ("KASAN:
slab-use-after-free Read in hci_conn_hash_flush"). This bug was
originally fixed by commit 5dc7d23e16 ("Bluetooth: hci_conn: Fix
possible UAF").
The hci_conn_unlink function was added to avoid invalidating the link
traversal caused by successive hci_conn_del operations releasing extra
connections. However, currently hci_conn_unlink itself also releases
extra connections, resulted in the reintroduced bug.
This patch follows a more robust solution for cleaning up all
connections, by repeatedly removing the first connection until there are
none left. This approach does not rely on the inner workings of
hci_conn_del and ensures proper cleanup of all connections.
Meanwhile, we need to make sure that hci_conn_del never fails. Indeed it
doesn't, as it now always returns zero. To make this a bit clearer, this
patch also changes its return type to void.
Reported-by: syzbot+8bb72f86fc823817bc5d@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-bluetooth/000000000000aa920505f60d25ad@google.com/
Fixes: 06149746e7 ("Bluetooth: hci_conn: Add support for linking multiple hcon")
Signed-off-by: Ruihan Li <lrh2000@pku.edu.cn>
Co-developed-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Pull sound fixes from Takashi Iwai:
"A collection of small fixes that have been gathered since rc1:
- Lots of small ASoC SOF Intel fixes
- A couple of UAF and NULL-dereference fixes
- Quirks and updates for HD-audio, USB-audio and ASoC AMD
- A few minor build / sparse warning fixes
- MAINTAINERS and DT updates"
* tag 'sound-6.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (38 commits)
ALSA: hda: Add NVIDIA codec IDs a3 through a7 to patch table
ALSA: oss: avoid missing-prototype warnings
ALSA: cs46xx: mark snd_cs46xx_download_image as static
ALSA: hda: Fix Oops by 9.1 surround channel names
ASoC: SOF: topology: Fix tuples array allocation
ASoC: SOF: Separate the tokens for input and output pin index
MAINTAINERS: Remove self from Cirrus Codec drivers
ASoC: cs35l56: Prevent unbalanced pm_runtime in dsp_work() on SoundWire
ASoC: SOF: topology: Fix logic for copying tuples
ASoC: SOF: pm: save io region state in case of errors in resume
ASoC: MAINTAINERS: drop Krzysztof Kozlowski from Samsung audio
ASoC: mediatek: mt8186: Fix use-after-free in driver remove path
ASoC: SOF: ipc3-topology: Make sure that only one cmd is sent in dai_config
ASoC: SOF: sof-client-probes: fix pm_runtime imbalance in error handling
ASoC: SOF: pcm: fix pm_runtime imbalance in error handling
ASoC: SOF: debug: conditionally bump runtime_pm counter on exceptions
ASoC: SOF: Intel: hda-mlink: add helper to program SoundWire PCMSyCM registers
ASoC: SOF: Intel: hda-mlink: initialize instance_offset member
ASoC: SOF: Intel: hda-mlink: use 'ml_addr' parameter consistently
ASoC: SOF: Intel: hda-mlink: fix base_ptr computation
...
Rename drm_sched_wakeup() to drm_sched_wakeup_if_canqueue() since the former
is misleading, as it wakes up the GPU scheduler _only if_ more jobs can be
queued to the underlying hardware.
This distinction is important to make, since the wake conditional in the GPU
scheduler thread wakes up when other conditions are also true, e.g. when there
are jobs to be cleaned. For instance, a user might want to wake up the
scheduler only because there are more jobs to clean, but whether we can queue
more jobs is irrelevant.
v2: Separate "canqueue" to "can_queue". (Alex D.)
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <Alexander.Deucher@amd.com>
Signed-off-by: Luben Tuikov <luben.tuikov@amd.com>
Link: https://lore.kernel.org/r/20230517233550.377847-2-luben.tuikov@amd.com
Reviewed-by: Alex Deucher <Alexander.Deucher@amd.com>
Add kerneldocs for ERR_PTR(), PTR_ERR(), PTR_ERR_OR_ZERO(), IS_ERR(),
and IS_ERR_OR_NULL(). Doing so will help convert hundreds of mentions
of them in existing documentation into automatic cross-references.
Also add kerneldocs for IS_ERR_VALUE(). Doing so adds no automatic
cross-references, but this macro has a slightly different use case
than the functionally similar IS_ERR(), and documenting it may be
helpful to readers who encounter it in existing code.
ERR_CAST() already has kerneldocs and has not been touched.
Signed-off-by: James Seo <james@equiv.tech>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20230509175543.2065835-3-james@equiv.tech
This implements a new interface to lockdep, lock_set_cmp_fn(), for
defining a custom ordering when taking multiple locks of the same
class.
This is an alternative to subclasses, but can not fully replace them
since subclasses allow lock hierarchies with other clasees
inter-twined, while this relies on pure class nesting.
Specifically, if A is our nesting class then:
A/0 <- B <- A/1
Would be a valid lock order with subclasses (each subclass really is a
full class from the validation PoV) but not with this annotation,
which requires all nesting to be consecutive.
Example output:
| ============================================
| WARNING: possible recursive locking detected
| 6.2.0-rc8-00003-g7d81e591ca6a-dirty #15 Not tainted
| --------------------------------------------
| kworker/14:3/938 is trying to acquire lock:
| ffff8880143218c8 (&b->lock l=0 0:2803368){++++}-{3:3}, at: bch_btree_node_get.part.0+0x81/0x2b0
|
| but task is already holding lock:
| ffff8880143de8c8 (&b->lock l=1 1048575:9223372036854775807){++++}-{3:3}, at: __bch_btree_map_nodes+0xea/0x1e0
| and the lock comparison function returns 1:
|
| other info that might help us debug this:
| Possible unsafe locking scenario:
|
| CPU0
| ----
| lock(&b->lock l=1 1048575:9223372036854775807);
| lock(&b->lock l=0 0:2803368);
|
| *** DEADLOCK ***
|
| May be due to missing lock nesting notation
|
| 3 locks held by kworker/14:3/938:
| #0: ffff888005ea9d38 ((wq_completion)bcache){+.+.}-{0:0}, at: process_one_work+0x1ec/0x530
| #1: ffff8880098c3e70 ((work_completion)(&cl->work)#3){+.+.}-{0:0}, at: process_one_work+0x1ec/0x530
| #2: ffff8880143de8c8 (&b->lock l=1 1048575:9223372036854775807){++++}-{3:3}, at: __bch_btree_map_nodes+0xea/0x1e0
[peterz: extended changelog]
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20230509195847.1745548-1-kent.overstreet@linux.dev
Instead of duplicating the sha256 block processing code, reuse
the common code from crypto/sha256_base.h.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The function sha224_update is exactly the same as sha256_update.
Moreover it's not even used in the kernel so it can be removed.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
When receive buffer is small we try to copy out the data from
TCP into a skb maintained by TLS to prevent connection from
stalling. Unfortunately if a single record is made up of a mix
of decrypted and non-decrypted skbs combining them into a single
skb leads to loss of decryption status, resulting in decryption
errors or data corruption.
Similarly when trying to use TCP receive queue directly we need
to make sure that all the skbs within the record have the same
status. If we don't the mixed status will be detected correctly
but we'll CoW the anchor, again collapsing it into a single paged
skb without decrypted status preserved. So the "fixup" code will
not know which parts of skb to re-encrypt.
Fixes: 84c61fe1a7 ("tls: rx: do not use the standard strparser")
Tested-by: Shai Amiram <samiram@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If a record is partially decrypted we'll have to CoW it, anyway,
so go into copy mode and allocate a writable skb right away.
This will make subsequent fix simpler because we won't have to
teach tls_strp_msg_make_copy() how to copy skbs while preserving
decrypt status.
Tested-by: Shai Amiram <samiram@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge series from Richard Fitzgerald <rf@opensource.cirrus.com>:
First two patches are bugfixes.
Third patch skips the overhead of rebooting the amp after applying
firmware files when we know that it isn't necessary.
No functional changes intended. The new helper will be used
by the MPTCP protocol in the next patch to avoid duplicating
a few LoC.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add support for parsing the rate select thresholds and switching of the
RS0 and RS1 signals to the transceiver. This is complicated by various
revisions of SFF-8472 and interaction of SFF-8431, SFF-8079 and
INF-8074.
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add support to the SFP layer to allow phylink to set the signalling
rate for a SFP module. The rate given will be in units of kilo-baud
(1000 baud).
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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>
Introduce the function blk_rq_is_seq_zoned_write(). This function will
be used in later patches to preserve the order of zoned writes that
require write serialization.
This patch includes an optimization: instead of using
rq->q->disk->part0->bd_queue to check whether or not the queue is
associated with a zoned block device, use rq->q->disk->queue.
Cc: Christoph Hellwig <hch@lst.de>
Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20230517174230.897144-6-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In case of q->elevator, passthrough request can still be marked as
RQF_ELV, so some elevator callbacks will be called for them.
Fix this by splitting RQF_SCHED_TAGS, which is set for all requests that
are issued on a queue that uses an I/O scheduler, and RQF_USE_SCHED for
non-flush, non-passthrough requests on such a queue.
Roughly based on two different patches from
Ming Lei <ming.lei@redhat.com>.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230518053101.760632-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull misc fixes from Andrew Morton:
"Eight hotfixes. Four are cc:stable, the other four are for post-6.4
issues, or aren't considered suitable for backporting"
* tag 'mm-hotfixes-stable-2023-05-18-15-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
MAINTAINERS: Cleanup Arm Display IP maintainers
MAINTAINERS: repair pattern in DIALOG SEMICONDUCTOR DRIVERS
nilfs2: fix use-after-free bug of nilfs_root in nilfs_evict_inode()
mm: fix zswap writeback race condition
mm: kfence: fix false positives on big endian
zsmalloc: move LRU update from zs_map_object() to zs_malloc()
mm: shrinkers: fix race condition on debugfs cleanup
maple_tree: make maple state reusable after mas_empty_area()
Conflicts:
drivers/net/ethernet/freescale/fec_main.c
6ead9c98ca ("net: fec: remove the xdp_return_frame when lack of tx BDs")
144470c88c ("net: fec: using the standard return codes when xdp xmit errors")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
There are two functions in the olpc platform that have no prototype:
arch/x86/platform/olpc/olpc_dt.c:237:13: error: no previous prototype for 'olpc_dt_fixup' [-Werror=missing-prototypes]
arch/x86/platform/olpc/olpc-xo1-pm.c:73:26: error: no previous prototype for 'xo1_do_sleep' [-Werror=missing-prototypes]
The first one should just be marked 'static' as there are no other
callers, while the second one is called from assembler and is
just a false-positive warning that can be silenced by adding a
prototype.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Link: https://lore.kernel.org/all/20230516193549.544673-21-arnd%40kernel.org
early_memremap_pgprot_adjust() is a __weak function with a local
prototype, but x86 has a custom implementation that does not
see the prototype, causing a W=1 warning:
arch/x86/mm/ioremap.c:785:17: error: no previous prototype for 'early_memremap_pgprot_adjust' [-Werror=missing-prototypes]
Move the declaration into the global linux/io.h header to avoid this.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Link: https://lore.kernel.org/all/20230516193549.544673-19-arnd%40kernel.org
Three functions that are defined in x86 specific code to override
generic __weak implementations cause a warning because of a missing
prototype:
arch/x86/power/cpu.c:298:5: error: no previous prototype for 'hibernate_resume_nonboot_cpu_disable' [-Werror=missing-prototypes]
arch/x86/power/hibernate.c:129:5: error: no previous prototype for 'arch_hibernation_header_restore' [-Werror=missing-prototypes]
arch/x86/power/hibernate.c:91:5: error: no previous prototype for 'arch_hibernation_header_save' [-Werror=missing-prototypes]
Move the declarations into a global header so it can be included
by any file defining one of these.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Link: https://lore.kernel.org/all/20230516193549.544673-14-arnd%40kernel.org
Instead of exposing inner workings of libps2 to drivers such as atkbd and
psmouse, have them define pre-receive and receive callbacks, and provide a
common handler that can be used with underlying serio port.
While at this add kerneldoc to the module.
Link: https://lore.kernel.org/r/ZGK81cxqjr/KS1kA@google.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
When getting unexpected data while waiting for an acknowledgement it does
not matter what command phase is currently executed, and ps2_handle_ack()
should indicate that no further processing is needed for the received data
byte. Remove PS2_FLAG_ACK_CMD and associated handling.
Note that while it is possible to make ps2_handle_ack (and
ps2_handle_repsonse) return void, it will be done when the code will be
converted to common PS/2 interrupt handler later.
Reviewed-by: Raul E Rangel <rrangel@chromium.org>
Link: https://lore.kernel.org/r/20230511185252.386941-3-dmitry.torokhov@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
