Skip to content

[PATCH v4 0/9] nvme-tcp WIP Time Based Recovery TP 4129#3

Draft
johnmeneghini wants to merge 35 commits intonvme-6.15from
tp4129_pure
Draft

[PATCH v4 0/9] nvme-tcp WIP Time Based Recovery TP 4129#3
johnmeneghini wants to merge 35 commits intonvme-6.15from
tp4129_pure

Conversation

@johnmeneghini
Copy link
Owner

@johnmeneghini johnmeneghini commented Mar 12, 2025

[jmeneghi@redhat.com] rebased to nvme-6.15

On 2/16/25 06:59, Mohamed Khalfella wrote:
Compared to v3 the patchset is smaller and should be easier to follow.
These changes can be easily ported to nvme-rdma since the two transports
are implemented similarly. Taking the changes to nvme-fc might take
more effort, maybe couple of days. Please take a look at the patchset
and let me know what do you think.

Changes from v3:

  • Do not continue controller recovery while inflight requests are held.
    Instead block controller recovery, reset, and delete codepaths until
    held requests are released.

  • Removed changes to block layer since they are no longer needed.

  • Blocking recovery and reset codepaths until held requests are released
    might trigger hung_task timeout. Use wait_for_completion_timeout() in
    a loop to avoid it. Also implemented and used flush_work_timeout() to
    avoid hung_task while waiting for reset_work to finish.

To be implemented from v3:

  • KATO wait short-circuit: Per my conversation with Randy, and in order
    to keep the diff small, will not implement this for nvme-tcp or
    nvme-rdma. We might implement it for nvme-fc.

  • CQT wait: Added

Known issues:

No known issues. This is probably because I tested these changes on VMs
with limited testing.

Next step. I think we need to converge on whether we should hold
inflight requests at the transport layer or nvme-multipath layer.

Changes from v2:

  • Hold all the inflight reqeusts during recovery or controller reset.
    Filtering admin/io retryable requests has been removed.

  • Requests are now held at nvme layer instead of block layer. Changes to
    block layer have been removed.

Known issues:

  • Testing resetting nvme controller from sysfs while IO is running I noticed
    that resets codepath freeze io queues. This freeze waits for held requests
    which matches the behavior we want. However, this has the downside of
    potentially triggering hung_task timeout on controller reset.

    nvme_reset_ctrl_work() ->
    nvme_tcp_setup_ctrl() ->
    nvme_tcp_configure_io_queues() ->
    nvme_wait_freeze_timeout()

  • I added the struct members to nvme_request with the assumption that we
    could be having multiple request sets held with different deadlines.
    This assumption is wrong. I will remove these members, which will simplify
    the patch, and only mark held requests by changing the request state.
    This should be enough not to trigger timeouts from block layer.

  • Having some requests in held state causes queue freeze to take longer
    because the usage counter will not drop to 0 until these requests are
    canceled. As pointed above, this might trigger hung task. I need to
    consider situations where we might have held requests and find a
    hung_task-friendly wait to add this wait.

I will continue working on addressing these issues on v4 of this change.

To be implemented, should be easy once we settle on how to hold requests.

  • KATO wait short-circuit: It is possible for initiator to confirm, with
    a certain degree of confidence, that target controller learnt about
    disconnection before KATO wait finishes. In this case it should be safe
    to cancel KATO wait to jump to CQT wait.

  • CQT wait: This is extra wait that gives target controller more time to
    process pending commands. Should not be difficult to add.

easwarh and others added 30 commits February 25, 2025 13:29
Commit b35108a ("jiffies: Define secs_to_jiffies()") introduced
secs_to_jiffies().  As the value here is a multiple of 1000, use
secs_to_jiffies() instead of msecs_to_jiffies() to avoid the multiplication

This is converted using scripts/coccinelle/misc/secs_to_jiffies.cocci with
the following Coccinelle rules:

@Depends on patch@ expression E; @@

-msecs_to_jiffies(E * 1000)
+secs_to_jiffies(E)

@Depends on patch@ expression E; @@

-msecs_to_jiffies(E * MSEC_PER_SEC)
+secs_to_jiffies(E)

While here, remove the no-longer necessary check for range since there's
no multiplication involved.

Acked-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Easwar Hariharan <eahariha@linux.microsoft.com>
Link: https://lore.kernel.org/r/20250225-converge-secs-to-jiffies-part-two-v3-6-a43967e36c88@linux.microsoft.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In case of an error, ublk's ->uring_cmd() functions currently return
-EIOCBQUEUED and immediately call io_uring_cmd_done(). -EIOCBQUEUED and
io_uring_cmd_done() are intended for asynchronous completions. For
synchronous completions, the ->uring_cmd() function can just return the
negative return code directly. This skips io_uring_cmd_del_cancelable(),
and deferring the completion to task work. So return the error code
directly from __ublk_ch_uring_cmd() and ublk_ctrl_uring_cmd().

Update ublk_ch_uring_cmd_cb(), which currently ignores the return value
from __ublk_ch_uring_cmd(), to call io_uring_cmd_done() for synchronous
completions.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20250225212456.2902549-1-csander@purestorage.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The null_blk configfs file 'features' provides a string that lists
available null_blk features for userspace programs to reference.
The string is defined as a long constant in the code, which tends to be
forgotten for updates. It also causes checkpatch.pl to report
"WARNING: quoted string split across lines".

To avoid these drawbacks, generate the feature string on the fly. Refer
to the ca_name field of each element in the nullb_device_attrs table and
concatenate them in the given buffer. Also, sorted nullb_device_attrs
table elements in alphabetical order.

Of note is that the feature "index" was missing before this commit.
This commit adds it to the generated string.

Suggested-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Link: https://lore.kernel.org/r/20250226100613.1622564-2-shinichiro.kawasaki@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When IO errors happen on real storage devices, the IOs repeated to the
same target range can success by virtue of recovery features by devices,
such as reserved block assignment. To simulate such IO errors and
recoveries, introduce the new parameter badblocks_once parameter. When
this parameter is set to 1, the specified badblocks are cleared after
the first IO error, so that the next IO to the blocks succeed.

Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Link: https://lore.kernel.org/r/20250226100613.1622564-3-shinichiro.kawasaki@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
As a preparation to support partial data transfer due to badblocks,
replace the null_process_cmd() call in null_zone_write() with equivalent
calls to null_handle_badblocks() and null_handle_memory_backed(). This
commit does not change behavior. It will enable null_handle_badblocks()
to return the size of partial data transfer in the following commit,
allowing null_zone_write() to move write pointers appropriately.

Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Link: https://lore.kernel.org/r/20250226100613.1622564-4-shinichiro.kawasaki@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
As preparation to support partial data transfer, add a new argument to
null_handle_rq() to pass the number of sectors to transfer. While at it,
rename the function from null_handle_rq to null_handle_data_transfer.
This commit does not change the behavior.

Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Link: https://lore.kernel.org/r/20250226100613.1622564-5-shinichiro.kawasaki@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The current null_blk implementation checks if any bad blocks exist in
the target blocks of each IO. If so, the IO fails and data is not
transferred for all of the IO target blocks. However, when real storage
devices have bad blocks, the devices may transfer data partially up to
the first bad blocks (e.g., SAS drives). Especially, when the IO is a
write operation, such partial IO leaves partially written data on the
device.

To simulate such partial IO using null_blk, introduce the new parameter
'badblocks_partial_io'. When this parameter is set,
null_handle_badblocks() returns the number of the sectors for the
partial IO as its third pointer argument. Pass the returned number of
sectors to the following calls to null_handle_memory_backend() in
null_process_cmd() and null_zone_write().

Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Link: https://lore.kernel.org/r/20250226100613.1622564-6-shinichiro.kawasaki@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
None of the few drivers still using the legacy block layer bounce
buffering support integrity metadata.  Explicitly mark the features as
incompatible and stop creating the slab and mempool for integrity
buffers for the bounce bio_set.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20250225154449.422989-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The code that automatically creates a integrity payload and generates and
verifies the checksums for bios that don't have submitter-provided
integrity payload currently sits right in the middle of the block
integrity metadata infrastructure.  Split it into a separate file to
make the different layers clear.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20250225154449.422989-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Many of the fields in struct bio_integrity_payload are only needed for
the default integrity buffer in the block layer, and the variable
sized array at the end of the structure makes it very hard to embed
into caller allocated structures.

Reduce struct bio_integrity_payload to the minimal structure needed in
common code and create two separate containing structures for the
automatically generated payload and the caller allocated payload.
The latter is a simple wrapper for struct bio_integrity_payload and
the bvecs, while the former contains the additional fields moved out
of struct bio_integrity_payload.

Always use a dedicated mempool for automatic integrity metadata
instead of depending on bio_set that is submitter controlled and thus
often doesn't have the mempool initialized and stop using mempools for
the submitter buffers as they aren't in the NOIO I/O submission path
where we need to guarantee forward progress.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Link: https://lore.kernel.org/r/20250225154449.422989-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The in-tree ublk driver doesn't need DMA alignment limit because there
is one data copy between request pages and the userspace buffer.

However, ublk is going to support zero copy, then DMA alignment limit
is required, because same IO buffer is forwarded to backend which may
have specific buffer DMA alignment limit, so the limit has to be exposed
from the frontend driver to client application.

Cc: Keith Busch <kbusch@kernel.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250227103707.2640014-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Separate out the HKDF functions into a separate module to
to make them available to other callers.
And add a testsuite to the module with test vectors
from RFC 5869 (and additional vectors for SHA384 and SHA512)
to ensure the integrity of the algorithm.

Signed-off-by: Hannes Reinecke <hare@kernel.org>
Acked-by: Eric Biggers <ebiggers@kernel.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Add a function to generate a NVMe PSK from the shared credentials
negotiated by DH-HMAC-CHAP.

Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Add a function to calculate the PSK digest as specified in TP8018.

Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Add a function to derive the TLS PSK as specified TP8018.

Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Add a function to refresh a generated PSK in the specified keyring.

Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Add a fabrics option 'concat' to request secure channel concatenation as
specified the NVME Base Specification v2.1, section 8.3.4.3: Secure Channel
Concatenation.
When secure channel concatenation is enabled a 'generated PSK' is inserted
into the keyring such that it's available after reset.

Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>
When secure concatenation is requested the connection needs to be
reset to enable TLS encryption on the new cnnection.
That implies that the original connection used for the DH-CHAP
negotiation really shouldn't be used, and we should reset as soon
as the DH-CHAP negotiation has succeeded on the admin queue.

Based on an idea from Sagi.

Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>
For secure concatenation the result of the TLS handshake will be
stored in the 'sq' struct, so add it to the alloc_ctrl_args struct.

Cc: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Evaluate the SC_C flag during DH-CHAP-HMAC negotiation to check if secure
concatenation as specified in the NVMe Base Specification v2.1, section
8.3.4.3: "Secure Channel Concatenationand" is requested. If requested the
generated PSK is inserted into the keyring once negotiation has finished
allowing for an encrypted connection once the admin queue is restarted.

Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Add debugfs entries to display the 'concat' and 'tls_key' controller
attributes.

Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>
This patch helps add nvme native multipath visibility for round-robin
io-policy. It creates a "multipath" sysfs directory under head gendisk
device node directory and then from "multipath" directory it adds a link
to each namespace path device the head node refers.

For instance, if we have a shared namespace accessible from two different
controllers/paths then we create a soft link to each path device from head
disk node as shown below:

$ ls -l /sys/block/nvme1n1/multipath/
nvme1c1n1 -> ../../../../../pci052e:78/052e:78:00.0/nvme/nvme1/nvme1c1n1
nvme1c3n1 -> ../../../../../pci058e:78/058e:78:00.0/nvme/nvme3/nvme1c3n1

In the above example, nvme1n1 is head gendisk node created for a shared
namespace and the namespace is accessible from nvme1c1n1 and nvme1c3n1
paths.

For round-robin I/O policy, we could easily infer from the above output
that I/O workload targeted to nvme1n1 would toggle across paths nvme1c1n1
and nvme1c3n1.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
This patch helps add nvme native multipath visibility for numa io-policy.
It adds a new attribute file named "numa_nodes" under namespace gendisk
device path node which prints the list of numa nodes preferred by the
given namespace path. The numa nodes value is comma delimited list of
nodes or A-B range of nodes.

For instance, if we have a shared namespace accessible from two different
controllers/paths then accessing head node of the shared namespace would
show the following output:

$ ls -l /sys/block/nvme1n1/multipath/
nvme1c1n1 -> ../../../../../pci052e:78/052e:78:00.0/nvme/nvme1/nvme1c1n1
nvme1c3n1 -> ../../../../../pci058e:78/058e:78:00.0/nvme/nvme3/nvme1c3n1

In the above example, nvme1n1 is head gendisk node created for a shared
namespace and this namespace is accessible from nvme1c1n1 and nvme1c3n1
paths. For numa io-policy we can then refer the "numa_nodes" attribute
file created under each namespace path:

$ cat /sys/block/nvme1n1/multipath/nvme1c1n1/numa_nodes
0-1

$ cat /sys/block/nvme1n1/multipath/nvme1c3n1/numa_nodes
2-3

>From the above output, we infer that I/O workload targeted at nvme1n1
and running on numa nodes 0 and 1 would prefer using path nvme1c1n1.
Similarly, I/O workload running on numa nodes 2 and 3 would prefer
using path nvme1c3n1. Reading "numa_nodes" file when configured
io-policy is anything but numa would show no output.

Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
This patch helps add nvme native multipath visibility for queue-depth
io-policy. It adds a new attribute file named "queue_depth" under
namespace device path node which would print the number of active/
in-flight I/O requests currently queued for the given path.

For instance, if we have a shared namespace accessible from two different
controllers/paths then accessing head block node of the shared namespace
would show the following output:

$ ls -l /sys/block/nvme1n1/multipath/
nvme1c1n1 -> ../../../../../pci052e:78/052e:78:00.0/nvme/nvme1/nvme1c1n1
nvme1c3n1 -> ../../../../../pci058e:78/058e:78:00.0/nvme/nvme3/nvme1c3n1

In the above example, nvme1n1 is head gendisk node created for a shared
namespace and the namespace is accessible from nvme1c1n1 and nvme1c3n1
paths. For queue-depth io-policy we can then refer the "queue_depth"
attribute file created under each namespace path:

$ cat /sys/block/nvme1n1/multipath/nvme1c1n1/queue_depth
518

$cat /sys/block/nvme1n1/multipath/nvme1c3n1/queue_depth
504

>From the above output, we can infer that I/O workload targeted at nvme1n1
uses two paths nvme1c1n1 and nvme1c3n1 and the current queue depth of each
path is 518 and 504 respectively. Reading "queue_depth" file when
configured io-policy is anything but queue-depth would show no output.

Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Refactor nvme_fc_create_io_queues() and nvme_fc_recreate_io_queues() to
use the min3() macro to find the minimum between 3 values instead of
multiple min()'s. This shortens the code and makes it easier to read.

Signed-off-by: Qasim Ijaz <qasdev00@gmail.com>
Reviewed-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
The ns variable has been removed in commit 62451a2 ("nvme: separate
command prep and issue"). Drop reference to ns in comment.

Fixes: 62451a2 ("nvme: separate command prep and issue")
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
CQT wait tells us how much time in milliseconds nvme controller need to
quiesce pending commands. Read the it from identify controller response
and store in struct nvme_ctrl in cqt field. ctrl->cqt will be used later
on to calculate how much time to hold inflight requests when
connectivity is lost of nvme controller is reset.
… time

nvme request hold timeout is the time sufficient for target controller
to learn about loss of connectivity to initiator, and quiesce inflight
nvme commands being processed by target controller

The timeout has two components:

- KATO timeout is the time sufficient for target to learn about the
  connection loss to the target. It depends on whether command based or
  traffic based keepalive is used. As per TP4129 the timeout is supposed
  to be 3 x KATO for traffic based keepalive and 2 * KATO for command
  based keepalive.

- CQT is the time needed by target controller to quiesce in flight nvme
  commands after the controller learns about connection loss.
In preparation to add implement TP4129 move the code that frees tagset
out of nvme_tcp_teardown_io_queues().
…eue()

In preparation to implement TP4129 move the code that frees admin tagset
out of nvme_tcp_teardown_admin_queue().
johnmeneghini pushed a commit that referenced this pull request Sep 8, 2025
The QuickI2C ACPI _DSD methods return ICRS and ISUB data with a
trailing byte, making the actual length is one more byte than the
structs defined.

It caused stack-out-of-bounds and kernel crash:

kernel: BUG: KASAN: stack-out-of-bounds in quicki2c_acpi_get_dsd_property.constprop.0+0x111/0x1b0 [intel_quicki2c]
kernel: Write of size 12 at addr ffff888106d1f900 by task kworker/u33:2/75
kernel:
kernel: CPU: 3 UID: 0 PID: 75 Comm: kworker/u33:2 Not tainted 6.16.0+ #3 PREEMPT(voluntary)
kernel: Workqueue: async async_run_entry_fn
kernel: Call Trace:
kernel:  <TASK>
kernel:  dump_stack_lvl+0x76/0xa0
kernel:  print_report+0xd1/0x660
kernel:  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
kernel:  ? __kasan_slab_free+0x5d/0x80
kernel:  ? kasan_addr_to_slab+0xd/0xb0
kernel:  kasan_report+0xe1/0x120
kernel:  ? quicki2c_acpi_get_dsd_property.constprop.0+0x111/0x1b0 [intel_quicki2c]
kernel:  ? quicki2c_acpi_get_dsd_property.constprop.0+0x111/0x1b0 [intel_quicki2c]
kernel:  kasan_check_range+0x11c/0x200
kernel:  __asan_memcpy+0x3b/0x80
kernel:  quicki2c_acpi_get_dsd_property.constprop.0+0x111/0x1b0 [intel_quicki2c]
kernel:  ? __pfx_quicki2c_acpi_get_dsd_property.constprop.0+0x10/0x10 [intel_quicki2c]
kernel:  quicki2c_get_acpi_resources+0x237/0x730 [intel_quicki2c]
[...]
kernel:  </TASK>
kernel:
kernel: The buggy address belongs to stack of task kworker/u33:2/75
kernel:  and is located at offset 48 in frame:
kernel:  quicki2c_get_acpi_resources+0x0/0x730 [intel_quicki2c]
kernel:
kernel: This frame has 3 objects:
kernel:  [32, 36) 'hid_desc_addr'
kernel:  [48, 59) 'i2c_param'
kernel:  [80, 224) 'i2c_config'

ACPI DSD methods return:

\_SB.PC00.THC0.ICRS Buffer       000000003fdc947b 001 Len 0C = 0A 00 80 1A 06 00 00 00 00 00 00 00
\_SB.PC00.THC0.ISUB Buffer       00000000f2fcbdc4 001 Len 91 = 00 00 00 00 00 00 00 00 00 00 00 00

Adding reserved padding to quicki2c_subip_acpi_parameter/config.

Fixes: 5282e45 ("HID: intel-thc-hid: intel-quicki2c: Add THC QuickI2C ACPI interfaces")
Signed-off-by: Aaron Ma <aaron.ma@canonical.com>
Reviewed-by: Even Xu <even.xu@intel.com>
Tested-by: Even Xu <even.xu@intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
johnmeneghini pushed a commit that referenced this pull request Sep 8, 2025
…C regs save

Improper use of secondary pointer (&dev->i2c_subip_regs) caused
kernel crash and out-of-bounds error:

 BUG: KASAN: slab-out-of-bounds in _regmap_bulk_read+0x449/0x510
 Write of size 4 at addr ffff888136005dc0 by task kworker/u33:5/5107

 CPU: 3 UID: 0 PID: 5107 Comm: kworker/u33:5 Not tainted 6.16.0+ #3 PREEMPT(voluntary)
 Workqueue: async async_run_entry_fn
 Call Trace:
  <TASK>
  dump_stack_lvl+0x76/0xa0
  print_report+0xd1/0x660
  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
  ? kasan_complete_mode_report_info+0x26/0x200
  kasan_report+0xe1/0x120
  ? _regmap_bulk_read+0x449/0x510
  ? _regmap_bulk_read+0x449/0x510
  __asan_report_store4_noabort+0x17/0x30
  _regmap_bulk_read+0x449/0x510
  ? __pfx__regmap_bulk_read+0x10/0x10
  regmap_bulk_read+0x270/0x3d0
  pio_complete+0x1ee/0x2c0 [intel_thc]
  ? __pfx_pio_complete+0x10/0x10 [intel_thc]
  ? __pfx_pio_wait+0x10/0x10 [intel_thc]
  ? regmap_update_bits_base+0x13b/0x1f0
  thc_i2c_subip_pio_read+0x117/0x270 [intel_thc]
  thc_i2c_subip_regs_save+0xc2/0x140 [intel_thc]
  ? __pfx_thc_i2c_subip_regs_save+0x10/0x10 [intel_thc]
[...]
 The buggy address belongs to the object at ffff888136005d00
  which belongs to the cache kmalloc-rnd-12-192 of size 192
 The buggy address is located 0 bytes to the right of
  allocated 192-byte region [ffff888136005d00, ffff888136005dc0)

Replaced with direct array indexing (&dev->i2c_subip_regs[i]) to ensure
safe memory access.

Fixes: 4228966 ("HID: intel-thc-hid: intel-thc: Add THC I2C config interfaces")
Signed-off-by: Aaron Ma <aaron.ma@canonical.com>
Reviewed-by: Even Xu <even.xu@intel.com>
Tested-by: Even Xu <even.xu@intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
johnmeneghini pushed a commit that referenced this pull request Sep 8, 2025
A malicious HID device can trigger a slab out-of-bounds during
mt_report_fixup() by passing in report descriptor smaller than
607 bytes. mt_report_fixup() attempts to patch byte offset 607
of the descriptor with 0x25 by first checking if byte offset
607 is 0x15 however it lacks bounds checks to verify if the
descriptor is big enough before conducting this check. Fix
this bug by ensuring the descriptor size is at least 608
bytes before accessing it.

Below is the KASAN splat after the out of bounds access happens:

[   13.671954] ==================================================================
[   13.672667] BUG: KASAN: slab-out-of-bounds in mt_report_fixup+0x103/0x110
[   13.673297] Read of size 1 at addr ffff888103df39df by task kworker/0:1/10
[   13.673297]
[   13.673297] CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Not tainted 6.15.0-00005-gec5d573d83f4-dirty #3
[   13.673297] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/04
[   13.673297] Call Trace:
[   13.673297]  <TASK>
[   13.673297]  dump_stack_lvl+0x5f/0x80
[   13.673297]  print_report+0xd1/0x660
[   13.673297]  kasan_report+0xe5/0x120
[   13.673297]  __asan_report_load1_noabort+0x18/0x20
[   13.673297]  mt_report_fixup+0x103/0x110
[   13.673297]  hid_open_report+0x1ef/0x810
[   13.673297]  mt_probe+0x422/0x960
[   13.673297]  hid_device_probe+0x2e2/0x6f0
[   13.673297]  really_probe+0x1c6/0x6b0
[   13.673297]  __driver_probe_device+0x24f/0x310
[   13.673297]  driver_probe_device+0x4e/0x220
[   13.673297]  __device_attach_driver+0x169/0x320
[   13.673297]  bus_for_each_drv+0x11d/0x1b0
[   13.673297]  __device_attach+0x1b8/0x3e0
[   13.673297]  device_initial_probe+0x12/0x20
[   13.673297]  bus_probe_device+0x13d/0x180
[   13.673297]  device_add+0xe3a/0x1670
[   13.673297]  hid_add_device+0x31d/0xa40
[...]

Fixes: c8000de ("HID: multitouch: Add support for GT7868Q")
Cc: stable@vger.kernel.org
Signed-off-by: Qasim Ijaz <qasdev00@gmail.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
johnmeneghini pushed a commit that referenced this pull request Sep 8, 2025
When a large VM, specifically one that holds a significant number of PTEs,
gets abruptly destroyed, the following warning is seen during the
page-table walk:

 sched: CPU 0 need_resched set for > 100018840 ns (100 ticks) without schedule
 CPU: 0 UID: 0 PID: 9617 Comm: kvm_page_table_ Tainted: G O 6.16.0-smp-DEV #3 NONE
 Tainted: [O]=OOT_MODULE
 Call trace:
  show_stack+0x20/0x38 (C)
  dump_stack_lvl+0x3c/0xb8
  dump_stack+0x18/0x30
  resched_latency_warn+0x7c/0x88
  sched_tick+0x1c4/0x268
  update_process_times+0xa8/0xd8
  tick_nohz_handler+0xc8/0x168
  __hrtimer_run_queues+0x11c/0x338
  hrtimer_interrupt+0x104/0x308
  arch_timer_handler_phys+0x40/0x58
  handle_percpu_devid_irq+0x8c/0x1b0
  generic_handle_domain_irq+0x48/0x78
  gic_handle_irq+0x1b8/0x408
  call_on_irq_stack+0x24/0x30
  do_interrupt_handler+0x54/0x78
  el1_interrupt+0x44/0x88
  el1h_64_irq_handler+0x18/0x28
  el1h_64_irq+0x84/0x88
  stage2_free_walker+0x30/0xa0 (P)
  __kvm_pgtable_walk+0x11c/0x258
  __kvm_pgtable_walk+0x180/0x258
  __kvm_pgtable_walk+0x180/0x258
  __kvm_pgtable_walk+0x180/0x258
  kvm_pgtable_walk+0xc4/0x140
  kvm_pgtable_stage2_destroy+0x5c/0xf0
  kvm_free_stage2_pgd+0x6c/0xe8
  kvm_uninit_stage2_mmu+0x24/0x48
  kvm_arch_flush_shadow_all+0x80/0xa0
  kvm_mmu_notifier_release+0x38/0x78
  __mmu_notifier_release+0x15c/0x250
  exit_mmap+0x68/0x400
  __mmput+0x38/0x1c8
  mmput+0x30/0x68
  exit_mm+0xd4/0x198
  do_exit+0x1a4/0xb00
  do_group_exit+0x8c/0x120
  get_signal+0x6d4/0x778
  do_signal+0x90/0x718
  do_notify_resume+0x70/0x170
  el0_svc+0x74/0xd8
  el0t_64_sync_handler+0x60/0xc8
  el0t_64_sync+0x1b0/0x1b8

The warning is seen majorly on the host kernels that are configured
not to force-preempt, such as CONFIG_PREEMPT_NONE=y. To avoid this,
instead of walking the entire page-table in one go, split it into
smaller ranges, by checking for cond_resched() between each range.
Since the path is executed during VM destruction, after the
page-table structure is unlinked from the KVM MMU, relying on
cond_resched_rwlock_write() isn't necessary.

Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Suggested-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20250820162242.2624752-3-rananta@google.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
johnmeneghini pushed a commit that referenced this pull request Sep 8, 2025
These iterations require the read lock, otherwise RCU
lockdep will splat:

=============================
WARNING: suspicious RCU usage
6.17.0-rc3-00014-g31419c045d64 #6 Tainted: G           O
-----------------------------
drivers/base/power/main.c:1333 RCU-list traversed in non-reader section!!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
5 locks held by rtcwake/547:
 #0: 00000000643ab418 (sb_writers#6){.+.+}-{0:0}, at: file_start_write+0x2b/0x3a
 #1: 0000000067a0ca88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x181/0x24b
 #2: 00000000631eac40 (kn->active#3){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x191/0x24b
 #3: 00000000609a1308 (system_transition_mutex){+.+.}-{4:4}, at: pm_suspend+0xaf/0x30b
 #4: 0000000060c0fdb0 (device_links_srcu){.+.+}-{0:0}, at: device_links_read_lock+0x75/0x98

stack backtrace:
CPU: 0 UID: 0 PID: 547 Comm: rtcwake Tainted: G           O        6.17.0-rc3-00014-g31419c045d64 #6 VOLUNTARY
Tainted: [O]=OOT_MODULE
Stack:
 223721b3a80 6089eac6 00000001 00000001
 ffffff00 6089eac6 00000535 6086e528
 721b3ac0 6003c294 00000000 60031fc0
Call Trace:
 [<600407ed>] show_stack+0x10e/0x127
 [<6003c294>] dump_stack_lvl+0x77/0xc6
 [<6003c2fd>] dump_stack+0x1a/0x20
 [<600bc2f8>] lockdep_rcu_suspicious+0x116/0x13e
 [<603d8ea1>] dpm_async_suspend_superior+0x117/0x17e
 [<603d980f>] device_suspend+0x528/0x541
 [<603da24b>] dpm_suspend+0x1a2/0x267
 [<603da837>] dpm_suspend_start+0x5d/0x72
 [<600ca0c9>] suspend_devices_and_enter+0xab/0x736
 [...]

Add the fourth argument to the iteration to annotate
this and avoid the splat.

Fixes: 0679963 ("PM: sleep: Make async suspend handle suppliers like parents")
Fixes: ed18738 ("PM: sleep: Make async resume handle consumers like children")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://patch.msgid.link/20250826134348.aba79f6e6299.I9ecf55da46ccf33778f2c018a82e1819d815b348@changeid
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
johnmeneghini pushed a commit that referenced this pull request Sep 8, 2025
When the "proxy" option is enabled on a VXLAN device, the device will
suppress ARP requests and IPv6 Neighbor Solicitation messages if it is
able to reply on behalf of the remote host. That is, if a matching and
valid neighbor entry is configured on the VXLAN device whose MAC address
is not behind the "any" remote (0.0.0.0 / ::).

The code currently assumes that the FDB entry for the neighbor's MAC
address points to a valid remote destination, but this is incorrect if
the entry is associated with an FDB nexthop group. This can result in a
NPD [1][3] which can be reproduced using [2][4].

Fix by checking that the remote destination exists before dereferencing
it.

[1]
BUG: kernel NULL pointer dereference, address: 0000000000000000
[...]
CPU: 4 UID: 0 PID: 365 Comm: arping Not tainted 6.17.0-rc2-virtme-g2a89cb21162c #2 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-4.fc41 04/01/2014
RIP: 0010:vxlan_xmit+0xb58/0x15f0
[...]
Call Trace:
 <TASK>
 dev_hard_start_xmit+0x5d/0x1c0
 __dev_queue_xmit+0x246/0xfd0
 packet_sendmsg+0x113a/0x1850
 __sock_sendmsg+0x38/0x70
 __sys_sendto+0x126/0x180
 __x64_sys_sendto+0x24/0x30
 do_syscall_64+0xa4/0x260
 entry_SYSCALL_64_after_hwframe+0x4b/0x53

[2]
 #!/bin/bash

 ip address add 192.0.2.1/32 dev lo

 ip nexthop add id 1 via 192.0.2.2 fdb
 ip nexthop add id 10 group 1 fdb

 ip link add name vx0 up type vxlan id 10010 local 192.0.2.1 dstport 4789 proxy

 ip neigh add 192.0.2.3 lladdr 00:11:22:33:44:55 nud perm dev vx0

 bridge fdb add 00:11:22:33:44:55 dev vx0 self static nhid 10

 arping -b -c 1 -s 192.0.2.1 -I vx0 192.0.2.3

[3]
BUG: kernel NULL pointer dereference, address: 0000000000000000
[...]
CPU: 13 UID: 0 PID: 372 Comm: ndisc6 Not tainted 6.17.0-rc2-virtmne-g6ee90cb26014 #3 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1v996), BIOS 1.17.0-4.fc41 04/01/2x014
RIP: 0010:vxlan_xmit+0x803/0x1600
[...]
Call Trace:
 <TASK>
 dev_hard_start_xmit+0x5d/0x1c0
 __dev_queue_xmit+0x246/0xfd0
 ip6_finish_output2+0x210/0x6c0
 ip6_finish_output+0x1af/0x2b0
 ip6_mr_output+0x92/0x3e0
 ip6_send_skb+0x30/0x90
 rawv6_sendmsg+0xe6e/0x12e0
 __sock_sendmsg+0x38/0x70
 __sys_sendto+0x126/0x180
 __x64_sys_sendto+0x24/0x30
 do_syscall_64+0xa4/0x260
 entry_SYSCALL_64_after_hwframe+0x4b/0x53
RIP: 0033:0x7f383422ec77

[4]
 #!/bin/bash

 ip address add 2001:db8:1::1/128 dev lo

 ip nexthop add id 1 via 2001:db8:1::1 fdb
 ip nexthop add id 10 group 1 fdb

 ip link add name vx0 up type vxlan id 10010 local 2001:db8:1::1 dstport 4789 proxy

 ip neigh add 2001:db8:1::3 lladdr 00:11:22:33:44:55 nud perm dev vx0

 bridge fdb add 00:11:22:33:44:55 dev vx0 self static nhid 10

 ndisc6 -r 1 -s 2001:db8:1::1 -w 1 2001:db8:1::3 vx0

Fixes: 1274e1c ("vxlan: ecmp support for mac fdb entries")
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20250901065035.159644-3-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
johnmeneghini pushed a commit that referenced this pull request Sep 8, 2025
Ido Schimmel says:

====================
vxlan: Fix NPDs when using nexthop objects

With FDB nexthop groups, VXLAN FDB entries do not necessarily point to
a remote destination but rather to an FDB nexthop group. This means that
first_remote_{rcu,rtnl}() can return NULL and a few places in the driver
were not ready for that, resulting in NULL pointer dereferences.
Patches #1-#2 fix these NPDs.

Note that vxlan_fdb_find_uc() still dereferences the remote returned by
first_remote_rcu() without checking that it is not NULL, but this
function is only invoked by a single driver which vetoes the creation of
FDB nexthop groups. I will patch this in net-next to make the code less
fragile.

Patch #3 adds a selftests which exercises these code paths and tests
basic Tx functionality with FDB nexthop groups. I verified that the test
crashes the kernel without the first two patches.
====================

Link: https://patch.msgid.link/20250901065035.159644-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
johnmeneghini pushed a commit that referenced this pull request Sep 8, 2025
When transmitting a PTP frame which is timestamp using 2 step, the
following warning appears if CONFIG_PROVE_LOCKING is enabled:
=============================
[ BUG: Invalid wait context ]
6.17.0-rc1-00326-ge6160462704e #427 Not tainted
-----------------------------
ptp4l/119 is trying to lock:
c2a44ed4 (&vsc8531->ts_lock){+.+.}-{3:3}, at: vsc85xx_txtstamp+0x50/0xac
other info that might help us debug this:
context-{4:4}
4 locks held by ptp4l/119:
 #0: c145f068 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x58/0x1440
 #1: c29df974 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x5c4/0x1440
 #2: c2aaaad0 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x108/0x350
 #3: c2aac170 (&lan966x->tx_lock){+.-.}-{2:2}, at: lan966x_port_xmit+0xd0/0x350
stack backtrace:
CPU: 0 UID: 0 PID: 119 Comm: ptp4l Not tainted 6.17.0-rc1-00326-ge6160462704e #427 NONE
Hardware name: Generic DT based system
Call trace:
 unwind_backtrace from show_stack+0x10/0x14
 show_stack from dump_stack_lvl+0x7c/0xac
 dump_stack_lvl from __lock_acquire+0x8e8/0x29dc
 __lock_acquire from lock_acquire+0x108/0x38c
 lock_acquire from __mutex_lock+0xb0/0xe78
 __mutex_lock from mutex_lock_nested+0x1c/0x24
 mutex_lock_nested from vsc85xx_txtstamp+0x50/0xac
 vsc85xx_txtstamp from lan966x_fdma_xmit+0xd8/0x3a8
 lan966x_fdma_xmit from lan966x_port_xmit+0x1bc/0x350
 lan966x_port_xmit from dev_hard_start_xmit+0xc8/0x2c0
 dev_hard_start_xmit from sch_direct_xmit+0x8c/0x350
 sch_direct_xmit from __dev_queue_xmit+0x680/0x1440
 __dev_queue_xmit from packet_sendmsg+0xfa4/0x1568
 packet_sendmsg from __sys_sendto+0x110/0x19c
 __sys_sendto from sys_send+0x18/0x20
 sys_send from ret_fast_syscall+0x0/0x1c
Exception stack(0xf0b05fa8 to 0xf0b05ff0)
5fa0:                   00000001 0000000 0000000 0004b47a 0000003a 00000000
5fc0: 00000001 0000000 00000000 00000121 0004af58 00044874 00000000 00000000
5fe0: 00000001 bee9d420 00025a10 b6e75c7c

So, instead of using the ts_lock for tx_queue, use the spinlock that
skb_buff_head has.

Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Fixes: 7d272e6 ("net: phy: mscc: timestamping and PHC support")
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Link: https://patch.msgid.link/20250902121259.3257536-1-horatiu.vultur@microchip.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
johnmeneghini pushed a commit that referenced this pull request Sep 16, 2025
Problem description
===================

Lockdep reports a possible circular locking dependency (AB/BA) between
&pl->state_mutex and &phy->lock, as follows.

phylink_resolve() // acquires &pl->state_mutex
-> phylink_major_config()
   -> phy_config_inband() // acquires &pl->phydev->lock

whereas all the other call sites where &pl->state_mutex and
&pl->phydev->lock have the locking scheme reversed. Everywhere else,
&pl->phydev->lock is acquired at the top level, and &pl->state_mutex at
the lower level. A clear example is phylink_bringup_phy().

The outlier is the newly introduced phy_config_inband() and the existing
lock order is the correct one. To understand why it cannot be the other
way around, it is sufficient to consider phylink_phy_change(), phylink's
callback from the PHY device's phy->phy_link_change() virtual method,
invoked by the PHY state machine.

phy_link_up() and phy_link_down(), the (indirect) callers of
phylink_phy_change(), are called with &phydev->lock acquired.
Then phylink_phy_change() acquires its own &pl->state_mutex, to
serialize changes made to its pl->phy_state and pl->link_config.
So all other instances of &pl->state_mutex and &phydev->lock must be
consistent with this order.

Problem impact
==============

I think the kernel runs a serious deadlock risk if an existing
phylink_resolve() thread, which results in a phy_config_inband() call,
is concurrent with a phy_link_up() or phy_link_down() call, which will
deadlock on &pl->state_mutex in phylink_phy_change(). Practically
speaking, the impact may be limited by the slow speed of the medium
auto-negotiation protocol, which makes it unlikely for the current state
to still be unresolved when a new one is detected, but I think the
problem is there. Nonetheless, the problem was discovered using lockdep.

Proposed solution
=================

Practically speaking, the phy_config_inband() requirement of having
phydev->lock acquired must transfer to the caller (phylink is the only
caller). There, it must bubble up until immediately before
&pl->state_mutex is acquired, for the cases where that takes place.

Solution details, considerations, notes
=======================================

This is the phy_config_inband() call graph:

                          sfp_upstream_ops :: connect_phy()
                          |
                          v
                          phylink_sfp_connect_phy()
                          |
                          v
                          phylink_sfp_config_phy()
                          |
                          |   sfp_upstream_ops :: module_insert()
                          |   |
                          |   v
                          |   phylink_sfp_module_insert()
                          |   |
                          |   |   sfp_upstream_ops :: module_start()
                          |   |   |
                          |   |   v
                          |   |   phylink_sfp_module_start()
                          |   |   |
                          |   v   v
                          |   phylink_sfp_config_optical()
 phylink_start()          |   |
   |   phylink_resume()   v   v
   |   |  phylink_sfp_set_config()
   |   |  |
   v   v  v
 phylink_mac_initial_config()
   |   phylink_resolve()
   |   |  phylink_ethtool_ksettings_set()
   v   v  v
   phylink_major_config()
            |
            v
    phy_config_inband()

phylink_major_config() caller #1, phylink_mac_initial_config(), does not
acquire &pl->state_mutex nor do its callers. It must acquire
&pl->phydev->lock prior to calling phylink_major_config().

phylink_major_config() caller #2, phylink_resolve() acquires
&pl->state_mutex, thus also needs to acquire &pl->phydev->lock.

phylink_major_config() caller #3, phylink_ethtool_ksettings_set(), is
completely uninteresting, because it only calls phylink_major_config()
if pl->phydev is NULL (otherwise it calls phy_ethtool_ksettings_set()).
We need to change nothing there.

Other solutions
===============

The lock inversion between &pl->state_mutex and &pl->phydev->lock has
occurred at least once before, as seen in commit c718af2 ("net:
phylink: fix ethtool -A with attached PHYs"). The solution there was to
simply not call phy_set_asym_pause() under the &pl->state_mutex. That
cannot be extended to our case though, where the phy_config_inband()
call is much deeper inside the &pl->state_mutex section.

Fixes: 5fd0f1a ("net: phylink: add negotiation of in-band capabilities")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/20250904125238.193990-2-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
johnmeneghini pushed a commit that referenced this pull request Sep 25, 2025
…ux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 changes for 6.17, round #3

 - Invalidate nested MMUs upon freeing the PGD to avoid WARNs when
   visiting from an MMU notifier

 - Fixes to the TLB match process and TLB invalidation range for
   managing the VCNR pseudo-TLB

 - Prevent SPE from erroneously profiling guests due to UNKNOWN reset
   values in PMSCR_EL1

 - Fix save/restore of host MDCR_EL2 to account for eagerly programming
   at vcpu_load() on VHE systems

 - Correct lock ordering when dealing with VGIC LPIs, avoiding scenarios
   where an xarray's spinlock was nested with a *raw* spinlock

 - Permit stage-2 read permission aborts which are possible in the case
   of NV depending on the guest hypervisor's stage-2 translation

 - Call raw_spin_unlock() instead of the internal spinlock API

 - Fix parameter ordering when assigning VBAR_EL1
johnmeneghini pushed a commit that referenced this pull request Sep 30, 2025
We check the version of SPE twice, and we'll add one more check in the
next commit so factor out a macro to do this. Change the #3 magic number
to the actual SPE version define (V1p2) to make it more readable.

No functional changes intended.

Tested-by: Leo Yan <leo.yan@arm.com>
Reviewed-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: James Clark <james.clark@linaro.org>
Signed-off-by: Will Deacon <will@kernel.org>
johnmeneghini pushed a commit that referenced this pull request Sep 30, 2025
This fixes the following UAF caused by not properly locking hdev when
processing HCI_EV_NUM_COMP_PKTS:

BUG: KASAN: slab-use-after-free in hci_conn_tx_dequeue+0x1be/0x220 net/bluetooth/hci_conn.c:3036
Read of size 4 at addr ffff8880740f0940 by task kworker/u11:0/54

CPU: 1 UID: 0 PID: 54 Comm: kworker/u11:0 Not tainted 6.16.0-rc7 #3 PREEMPT(full)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
Workqueue: hci1 hci_rx_work
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x230 mm/kasan/report.c:480
 kasan_report+0x118/0x150 mm/kasan/report.c:593
 hci_conn_tx_dequeue+0x1be/0x220 net/bluetooth/hci_conn.c:3036
 hci_num_comp_pkts_evt+0x1c8/0xa50 net/bluetooth/hci_event.c:4404
 hci_event_func net/bluetooth/hci_event.c:7477 [inline]
 hci_event_packet+0x7e0/0x1200 net/bluetooth/hci_event.c:7531
 hci_rx_work+0x46a/0xe80 net/bluetooth/hci_core.c:4070
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 home/kwqcheii/source/fuzzing/kernel/kasan/linux-6.16-rc7/arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 54:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4359
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 __hci_conn_add+0x233/0x1b30 net/bluetooth/hci_conn.c:939
 le_conn_complete_evt+0x3d6/0x1220 net/bluetooth/hci_event.c:5628
 hci_le_enh_conn_complete_evt+0x189/0x470 net/bluetooth/hci_event.c:5794
 hci_event_func net/bluetooth/hci_event.c:7474 [inline]
 hci_event_packet+0x78c/0x1200 net/bluetooth/hci_event.c:7531
 hci_rx_work+0x46a/0xe80 net/bluetooth/hci_core.c:4070
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 home/kwqcheii/source/fuzzing/kernel/kasan/linux-6.16-rc7/arch/x86/entry/entry_64.S:245

Freed by task 9572:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2381 [inline]
 slab_free mm/slub.c:4643 [inline]
 kfree+0x18e/0x440 mm/slub.c:4842
 device_release+0x9c/0x1c0
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x22b/0x480 lib/kobject.c:737
 hci_conn_cleanup net/bluetooth/hci_conn.c:175 [inline]
 hci_conn_del+0x8ff/0xcb0 net/bluetooth/hci_conn.c:1173
 hci_abort_conn_sync+0x5d1/0xdf0 net/bluetooth/hci_sync.c:5689
 hci_cmd_sync_work+0x210/0x3a0 net/bluetooth/hci_sync.c:332
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 home/kwqcheii/source/fuzzing/kernel/kasan/linux-6.16-rc7/arch/x86/entry/entry_64.S:245

Fixes: 134f4b3 ("Bluetooth: add support for skb TX SND/COMPLETION timestamping")
Reported-by: Junvyyang, Tencent Zhuque Lab <zhuque@tencent.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
johnmeneghini pushed a commit that referenced this pull request Sep 30, 2025
This fixes the following UFA in hci_acl_create_conn_sync where a
connection still pending is command submission (conn->state == BT_OPEN)
maybe freed, also since this also can happen with the likes of
hci_le_create_conn_sync fix it as well:

BUG: KASAN: slab-use-after-free in hci_acl_create_conn_sync+0x5ef/0x790 net/bluetooth/hci_sync.c:6861
Write of size 2 at addr ffff88805ffcc038 by task kworker/u11:2/9541

CPU: 1 UID: 0 PID: 9541 Comm: kworker/u11:2 Not tainted 6.16.0-rc7 #3 PREEMPT(full)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
Workqueue: hci3 hci_cmd_sync_work
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x230 mm/kasan/report.c:480
 kasan_report+0x118/0x150 mm/kasan/report.c:593
 hci_acl_create_conn_sync+0x5ef/0x790 net/bluetooth/hci_sync.c:6861
 hci_cmd_sync_work+0x210/0x3a0 net/bluetooth/hci_sync.c:332
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 home/kwqcheii/source/fuzzing/kernel/kasan/linux-6.16-rc7/arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 123736:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4359
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 __hci_conn_add+0x233/0x1b30 net/bluetooth/hci_conn.c:939
 hci_conn_add_unset net/bluetooth/hci_conn.c:1051 [inline]
 hci_connect_acl+0x16c/0x4e0 net/bluetooth/hci_conn.c:1634
 pair_device+0x418/0xa70 net/bluetooth/mgmt.c:3556
 hci_mgmt_cmd+0x9c9/0xef0 net/bluetooth/hci_sock.c:1719
 hci_sock_sendmsg+0x6ca/0xef0 net/bluetooth/hci_sock.c:1839
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x219/0x270 net/socket.c:727
 sock_write_iter+0x258/0x330 net/socket.c:1131
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x54b/0xa90 fs/read_write.c:686
 ksys_write+0x145/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 103680:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2381 [inline]
 slab_free mm/slub.c:4643 [inline]
 kfree+0x18e/0x440 mm/slub.c:4842
 device_release+0x9c/0x1c0
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x22b/0x480 lib/kobject.c:737
 hci_conn_cleanup net/bluetooth/hci_conn.c:175 [inline]
 hci_conn_del+0x8ff/0xcb0 net/bluetooth/hci_conn.c:1173
 hci_conn_complete_evt+0x3c7/0x1040 net/bluetooth/hci_event.c:3199
 hci_event_func net/bluetooth/hci_event.c:7477 [inline]
 hci_event_packet+0x7e0/0x1200 net/bluetooth/hci_event.c:7531
 hci_rx_work+0x46a/0xe80 net/bluetooth/hci_core.c:4070
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 home/kwqcheii/source/fuzzing/kernel/kasan/linux-6.16-rc7/arch/x86/entry/entry_64.S:245

Last potentially related work creation:
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47
 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548
 insert_work+0x3d/0x330 kernel/workqueue.c:2183
 __queue_work+0xbd9/0xfe0 kernel/workqueue.c:2345
 queue_delayed_work_on+0x18b/0x280 kernel/workqueue.c:2561
 pairing_complete+0x1e7/0x2b0 net/bluetooth/mgmt.c:3451
 pairing_complete_cb+0x1ac/0x230 net/bluetooth/mgmt.c:3487
 hci_connect_cfm include/net/bluetooth/hci_core.h:2064 [inline]
 hci_conn_failed+0x24d/0x310 net/bluetooth/hci_conn.c:1275
 hci_conn_complete_evt+0x3c7/0x1040 net/bluetooth/hci_event.c:3199
 hci_event_func net/bluetooth/hci_event.c:7477 [inline]
 hci_event_packet+0x7e0/0x1200 net/bluetooth/hci_event.c:7531
 hci_rx_work+0x46a/0xe80 net/bluetooth/hci_core.c:4070
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 home/kwqcheii/source/fuzzing/kernel/kasan/linux-6.16-rc7/arch/x86/entry/entry_64.S:245

Fixes: aef2aa4 ("Bluetooth: hci_event: Fix creating hci_conn object on error status")
Reported-by: Junvyyang, Tencent Zhuque Lab <zhuque@tencent.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
johnmeneghini pushed a commit that referenced this pull request Sep 30, 2025
Ido Schimmel says:

====================
nexthop: Various fixes

Patch #1 fixes a NPD that was recently reported by syzbot.

Patch #2 fixes an issue in the existing FIB nexthop selftest.

Patch #3 extends the selftest with test cases for the bug that was fixed
in the first patch.
====================

Link: https://patch.msgid.link/20250921150824.149157-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
johnmeneghini pushed a commit that referenced this pull request Oct 24, 2025
Expand the prefault memory selftest to add a regression test for a KVM bug
where KVM's retry logic would result in (breakable) deadlock due to the
memslot deletion waiting on prefaulting to release SRCU, and prefaulting
waiting on the memslot to fully disappear (KVM uses a two-step process to
delete memslots, and KVM x86 retries page faults if a to-be-deleted, a.k.a.
INVALID, memslot is encountered).

To exercise concurrent memslot remove, spawn a second thread to initiate
memslot removal at roughly the same time as prefaulting.  Test memslot
removal for all testcases, i.e. don't limit concurrent removal to only the
success case.  There are essentially three prefault scenarios (so far)
that are of interest:

 1. Success
 2. ENOENT due to no memslot
 3. EAGAIN due to INVALID memslot

For all intents and purposes, #1 and #2 are mutually exclusive, or rather,
easier to test via separate testcases since writing to non-existent memory
is trivial.  But for #3, making it mutually exclusive with #1 _or_ #2 is
actually more complex than testing memslot removal for all scenarios.  The
only requirement to let memslot removal coexist with other scenarios is a
way to guarantee a stable result, e.g. that the "no memslot" test observes
ENOENT, not EAGAIN, for the final checks.

So, rather than make memslot removal mutually exclusive with the ENOENT
scenario, simply restore the memslot and retry prefaulting.  For the "no
memslot" case, KVM_PRE_FAULT_MEMORY should be idempotent, i.e. should
always fail with ENOENT regardless of how many times userspace attempts
prefaulting.

Pass in both the base GPA and the offset (instead of the "full" GPA) so
that the worker can recreate the memslot.

Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Co-developed-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20250924174255.2141847-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
johnmeneghini pushed a commit that referenced this pull request Oct 24, 2025
Since blamed commit, unregister_netdevice_many_notify() takes the netdev
mutex if the device needs it.

If the device list is too long, this will lock more device mutexes than
lockdep can handle:

unshare -n \
 bash -c 'for i in $(seq 1 100);do ip link add foo$i type dummy;done'

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by kworker/u16:1/69:
 #0: ..148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work
 #1: ..d40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work
 #2: ..bd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net
 #3: ..aa8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch
 #4: ..cb0 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: unregister_netdevice_many_notify
[..]

Add a helper to close and then unlock a list of net_devices.
Devices that are not up have to be skipped - netif_close_many always
removes them from the list without any other actions taken, so they'd
remain in locked state.

Close devices whenever we've used up half of the tracking slots or we
processed entire list without hitting the limit.

Fixes: 7e4d784 ("net: hold netdev instance lock during rtnetlink operations")
Signed-off-by: Florian Westphal <fw@strlen.de>
Link: https://patch.msgid.link/20251013185052.14021-1-fw@strlen.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
johnmeneghini pushed a commit that referenced this pull request Oct 30, 2025
The original code causes a circular locking dependency found by lockdep.

======================================================
WARNING: possible circular locking dependency detected
6.16.0-rc6-lgci-xe-xe-pw-151626v3+ #1 Tainted: G S   U
------------------------------------------------------
xe_fault_inject/5091 is trying to acquire lock:
ffff888156815688 ((work_completion)(&(&devcd->del_wk)->work)){+.+.}-{0:0}, at: __flush_work+0x25d/0x660

but task is already holding lock:

ffff888156815620 (&devcd->mutex){+.+.}-{3:3}, at: dev_coredump_put+0x3f/0xa0
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&devcd->mutex){+.+.}-{3:3}:
       mutex_lock_nested+0x4e/0xc0
       devcd_data_write+0x27/0x90
       sysfs_kf_bin_write+0x80/0xf0
       kernfs_fop_write_iter+0x169/0x220
       vfs_write+0x293/0x560
       ksys_write+0x72/0xf0
       __x64_sys_write+0x19/0x30
       x64_sys_call+0x2bf/0x2660
       do_syscall_64+0x93/0xb60
       entry_SYSCALL_64_after_hwframe+0x76/0x7e
-> #1 (kn->active#236){++++}-{0:0}:
       kernfs_drain+0x1e2/0x200
       __kernfs_remove+0xae/0x400
       kernfs_remove_by_name_ns+0x5d/0xc0
       remove_files+0x54/0x70
       sysfs_remove_group+0x3d/0xa0
       sysfs_remove_groups+0x2e/0x60
       device_remove_attrs+0xc7/0x100
       device_del+0x15d/0x3b0
       devcd_del+0x19/0x30
       process_one_work+0x22b/0x6f0
       worker_thread+0x1e8/0x3d0
       kthread+0x11c/0x250
       ret_from_fork+0x26c/0x2e0
       ret_from_fork_asm+0x1a/0x30
-> #0 ((work_completion)(&(&devcd->del_wk)->work)){+.+.}-{0:0}:
       __lock_acquire+0x1661/0x2860
       lock_acquire+0xc4/0x2f0
       __flush_work+0x27a/0x660
       flush_delayed_work+0x5d/0xa0
       dev_coredump_put+0x63/0xa0
       xe_driver_devcoredump_fini+0x12/0x20 [xe]
       devm_action_release+0x12/0x30
       release_nodes+0x3a/0x120
       devres_release_all+0x8a/0xd0
       device_unbind_cleanup+0x12/0x80
       device_release_driver_internal+0x23a/0x280
       device_driver_detach+0x14/0x20
       unbind_store+0xaf/0xc0
       drv_attr_store+0x21/0x50
       sysfs_kf_write+0x4a/0x80
       kernfs_fop_write_iter+0x169/0x220
       vfs_write+0x293/0x560
       ksys_write+0x72/0xf0
       __x64_sys_write+0x19/0x30
       x64_sys_call+0x2bf/0x2660
       do_syscall_64+0x93/0xb60
       entry_SYSCALL_64_after_hwframe+0x76/0x7e
other info that might help us debug this:
Chain exists of: (work_completion)(&(&devcd->del_wk)->work) --> kn->active#236 --> &devcd->mutex
 Possible unsafe locking scenario:
       CPU0                    CPU1
       ----                    ----
  lock(&devcd->mutex);
                               lock(kn->active#236);
                               lock(&devcd->mutex);
  lock((work_completion)(&(&devcd->del_wk)->work));
 *** DEADLOCK ***
5 locks held by xe_fault_inject/5091:
 #0: ffff8881129f9488 (sb_writers#5){.+.+}-{0:0}, at: ksys_write+0x72/0xf0
 #1: ffff88810c755078 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x123/0x220
 #2: ffff8881054811a0 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0x55/0x280
 #3: ffff888156815620 (&devcd->mutex){+.+.}-{3:3}, at: dev_coredump_put+0x3f/0xa0
 #4: ffffffff8359e020 (rcu_read_lock){....}-{1:2}, at: __flush_work+0x72/0x660
stack backtrace:
CPU: 14 UID: 0 PID: 5091 Comm: xe_fault_inject Tainted: G S   U              6.16.0-rc6-lgci-xe-xe-pw-151626v3+ #1 PREEMPT_{RT,(lazy)}
Tainted: [S]=CPU_OUT_OF_SPEC, [U]=USER
Hardware name: Micro-Star International Co., Ltd. MS-7D25/PRO Z690-A DDR4(MS-7D25), BIOS 1.10 12/13/2021
Call Trace:
 <TASK>
 dump_stack_lvl+0x91/0xf0
 dump_stack+0x10/0x20
 print_circular_bug+0x285/0x360
 check_noncircular+0x135/0x150
 ? register_lock_class+0x48/0x4a0
 __lock_acquire+0x1661/0x2860
 lock_acquire+0xc4/0x2f0
 ? __flush_work+0x25d/0x660
 ? mark_held_locks+0x46/0x90
 ? __flush_work+0x25d/0x660
 __flush_work+0x27a/0x660
 ? __flush_work+0x25d/0x660
 ? trace_hardirqs_on+0x1e/0xd0
 ? __pfx_wq_barrier_func+0x10/0x10
 flush_delayed_work+0x5d/0xa0
 dev_coredump_put+0x63/0xa0
 xe_driver_devcoredump_fini+0x12/0x20 [xe]
 devm_action_release+0x12/0x30
 release_nodes+0x3a/0x120
 devres_release_all+0x8a/0xd0
 device_unbind_cleanup+0x12/0x80
 device_release_driver_internal+0x23a/0x280
 ? bus_find_device+0xa8/0xe0
 device_driver_detach+0x14/0x20
 unbind_store+0xaf/0xc0
 drv_attr_store+0x21/0x50
 sysfs_kf_write+0x4a/0x80
 kernfs_fop_write_iter+0x169/0x220
 vfs_write+0x293/0x560
 ksys_write+0x72/0xf0
 __x64_sys_write+0x19/0x30
 x64_sys_call+0x2bf/0x2660
 do_syscall_64+0x93/0xb60
 ? __f_unlock_pos+0x15/0x20
 ? __x64_sys_getdents64+0x9b/0x130
 ? __pfx_filldir64+0x10/0x10
 ? do_syscall_64+0x1a2/0xb60
 ? clear_bhb_loop+0x30/0x80
 ? clear_bhb_loop+0x30/0x80
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x76e292edd574
Code: c7 00 16 00 00 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d d5 ea 0e 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 55 48 89 e5 48 83 ec 20 48 89
RSP: 002b:00007fffe247a828 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000076e292edd574
RDX: 000000000000000c RSI: 00006267f6306063 RDI: 000000000000000b
RBP: 000000000000000c R08: 000076e292fc4b20 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00006267f6306063
R13: 000000000000000b R14: 00006267e6859c00 R15: 000076e29322a000
 </TASK>
xe 0000:03:00.0: [drm] Xe device coredump has been deleted.

Fixes: 01daccf ("devcoredump : Serialize devcd_del work")
Cc: Mukesh Ojha <quic_mojha@quicinc.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org # v6.1+
Signed-off-by: Maarten Lankhorst <dev@lankhorst.se>
Cc: Matthew Brost <matthew.brost@intel.com>
Acked-by: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250723142416.1020423-1-dev@lankhorst.se
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
johnmeneghini pushed a commit that referenced this pull request Nov 10, 2025
On completion of i915_vma_pin_ww(), a synchronous variant of
dma_fence_work_commit() is called.  When pinning a VMA to GGTT address
space on a Cherry View family processor, or on a Broxton generation SoC
with VTD enabled, i.e., when stop_machine() is then called from
intel_ggtt_bind_vma(), that can potentially lead to lock inversion among
reservation_ww and cpu_hotplug locks.

[86.861179] ======================================================
[86.861193] WARNING: possible circular locking dependency detected
[86.861209] 6.15.0-rc5-CI_DRM_16515-gca0305cadc2d+ #1 Tainted: G     U
[86.861226] ------------------------------------------------------
[86.861238] i915_module_loa/1432 is trying to acquire lock:
[86.861252] ffffffff83489090 (cpu_hotplug_lock){++++}-{0:0}, at: stop_machine+0x1c/0x50
[86.861290]
but task is already holding lock:
[86.861303] ffffc90002e0b4c8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_vma_pin.constprop.0+0x39/0x1d0 [i915]
[86.862233]
which lock already depends on the new lock.
[86.862251]
the existing dependency chain (in reverse order) is:
[86.862265]
-> #5 (reservation_ww_class_mutex){+.+.}-{3:3}:
[86.862292]        dma_resv_lockdep+0x19a/0x390
[86.862315]        do_one_initcall+0x60/0x3f0
[86.862334]        kernel_init_freeable+0x3cd/0x680
[86.862353]        kernel_init+0x1b/0x200
[86.862369]        ret_from_fork+0x47/0x70
[86.862383]        ret_from_fork_asm+0x1a/0x30
[86.862399]
-> #4 (reservation_ww_class_acquire){+.+.}-{0:0}:
[86.862425]        dma_resv_lockdep+0x178/0x390
[86.862440]        do_one_initcall+0x60/0x3f0
[86.862454]        kernel_init_freeable+0x3cd/0x680
[86.862470]        kernel_init+0x1b/0x200
[86.862482]        ret_from_fork+0x47/0x70
[86.862495]        ret_from_fork_asm+0x1a/0x30
[86.862509]
-> #3 (&mm->mmap_lock){++++}-{3:3}:
[86.862531]        down_read_killable+0x46/0x1e0
[86.862546]        lock_mm_and_find_vma+0xa2/0x280
[86.862561]        do_user_addr_fault+0x266/0x8e0
[86.862578]        exc_page_fault+0x8a/0x2f0
[86.862593]        asm_exc_page_fault+0x27/0x30
[86.862607]        filldir64+0xeb/0x180
[86.862620]        kernfs_fop_readdir+0x118/0x480
[86.862635]        iterate_dir+0xcf/0x2b0
[86.862648]        __x64_sys_getdents64+0x84/0x140
[86.862661]        x64_sys_call+0x1058/0x2660
[86.862675]        do_syscall_64+0x91/0xe90
[86.862689]        entry_SYSCALL_64_after_hwframe+0x76/0x7e
[86.862703]
-> #2 (&root->kernfs_rwsem){++++}-{3:3}:
[86.862725]        down_write+0x3e/0xf0
[86.862738]        kernfs_add_one+0x30/0x3c0
[86.862751]        kernfs_create_dir_ns+0x53/0xb0
[86.862765]        internal_create_group+0x134/0x4c0
[86.862779]        sysfs_create_group+0x13/0x20
[86.862792]        topology_add_dev+0x1d/0x30
[86.862806]        cpuhp_invoke_callback+0x4b5/0x850
[86.862822]        cpuhp_issue_call+0xbf/0x1f0
[86.862836]        __cpuhp_setup_state_cpuslocked+0x111/0x320
[86.862852]        __cpuhp_setup_state+0xb0/0x220
[86.862866]        topology_sysfs_init+0x30/0x50
[86.862879]        do_one_initcall+0x60/0x3f0
[86.862893]        kernel_init_freeable+0x3cd/0x680
[86.862908]        kernel_init+0x1b/0x200
[86.862921]        ret_from_fork+0x47/0x70
[86.862934]        ret_from_fork_asm+0x1a/0x30
[86.862947]
-> #1 (cpuhp_state_mutex){+.+.}-{3:3}:
[86.862969]        __mutex_lock+0xaa/0xed0
[86.862982]        mutex_lock_nested+0x1b/0x30
[86.862995]        __cpuhp_setup_state_cpuslocked+0x67/0x320
[86.863012]        __cpuhp_setup_state+0xb0/0x220
[86.863026]        page_alloc_init_cpuhp+0x2d/0x60
[86.863041]        mm_core_init+0x22/0x2d0
[86.863054]        start_kernel+0x576/0xbd0
[86.863068]        x86_64_start_reservations+0x18/0x30
[86.863084]        x86_64_start_kernel+0xbf/0x110
[86.863098]        common_startup_64+0x13e/0x141
[86.863114]
-> #0 (cpu_hotplug_lock){++++}-{0:0}:
[86.863135]        __lock_acquire+0x1635/0x2810
[86.863152]        lock_acquire+0xc4/0x2f0
[86.863166]        cpus_read_lock+0x41/0x100
[86.863180]        stop_machine+0x1c/0x50
[86.863194]        bxt_vtd_ggtt_insert_entries__BKL+0x3b/0x60 [i915]
[86.863987]        intel_ggtt_bind_vma+0x43/0x70 [i915]
[86.864735]        __vma_bind+0x55/0x70 [i915]
[86.865510]        fence_work+0x26/0xa0 [i915]
[86.866248]        fence_notify+0xa1/0x140 [i915]
[86.866983]        __i915_sw_fence_complete+0x8f/0x270 [i915]
[86.867719]        i915_sw_fence_commit+0x39/0x60 [i915]
[86.868453]        i915_vma_pin_ww+0x462/0x1360 [i915]
[86.869228]        i915_vma_pin.constprop.0+0x133/0x1d0 [i915]
[86.870001]        initial_plane_vma+0x307/0x840 [i915]
[86.870774]        intel_initial_plane_config+0x33f/0x670 [i915]
[86.871546]        intel_display_driver_probe_nogem+0x1c6/0x260 [i915]
[86.872330]        i915_driver_probe+0x7fa/0xe80 [i915]
[86.873057]        i915_pci_probe+0xe6/0x220 [i915]
[86.873782]        local_pci_probe+0x47/0xb0
[86.873802]        pci_device_probe+0xf3/0x260
[86.873817]        really_probe+0xf1/0x3c0
[86.873833]        __driver_probe_device+0x8c/0x180
[86.873848]        driver_probe_device+0x24/0xd0
[86.873862]        __driver_attach+0x10f/0x220
[86.873876]        bus_for_each_dev+0x7f/0xe0
[86.873892]        driver_attach+0x1e/0x30
[86.873904]        bus_add_driver+0x151/0x290
[86.873917]        driver_register+0x5e/0x130
[86.873931]        __pci_register_driver+0x7d/0x90
[86.873945]        i915_pci_register_driver+0x23/0x30 [i915]
[86.874678]        i915_init+0x37/0x120 [i915]
[86.875347]        do_one_initcall+0x60/0x3f0
[86.875369]        do_init_module+0x97/0x2a0
[86.875385]        load_module+0x2c54/0x2d80
[86.875398]        init_module_from_file+0x96/0xe0
[86.875413]        idempotent_init_module+0x117/0x330
[86.875426]        __x64_sys_finit_module+0x77/0x100
[86.875440]        x64_sys_call+0x24de/0x2660
[86.875454]        do_syscall_64+0x91/0xe90
[86.875470]        entry_SYSCALL_64_after_hwframe+0x76/0x7e
[86.875486]
other info that might help us debug this:
[86.875502] Chain exists of:
  cpu_hotplug_lock --> reservation_ww_class_acquire --> reservation_ww_class_mutex
[86.875539]  Possible unsafe locking scenario:
[86.875552]        CPU0                    CPU1
[86.875563]        ----                    ----
[86.875573]   lock(reservation_ww_class_mutex);
[86.875588]                                lock(reservation_ww_class_acquire);
[86.875606]                                lock(reservation_ww_class_mutex);
[86.875624]   rlock(cpu_hotplug_lock);
[86.875637]
 *** DEADLOCK ***
[86.875650] 3 locks held by i915_module_loa/1432:
[86.875663]  #0: ffff888101f5c1b0 (&dev->mutex){....}-{3:3}, at: __driver_attach+0x104/0x220
[86.875699]  #1: ffffc90002e0b4a0 (reservation_ww_class_acquire){+.+.}-{0:0}, at: i915_vma_pin.constprop.0+0x39/0x1d0 [i915]
[86.876512]  #2: ffffc90002e0b4c8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_vma_pin.constprop.0+0x39/0x1d0 [i915]
[86.877305]
stack backtrace:
[86.877326] CPU: 0 UID: 0 PID: 1432 Comm: i915_module_loa Tainted: G     U              6.15.0-rc5-CI_DRM_16515-gca0305cadc2d+ #1 PREEMPT(voluntary)
[86.877334] Tainted: [U]=USER
[86.877336] Hardware name:  /NUC5CPYB, BIOS PYBSWCEL.86A.0079.2020.0420.1316 04/20/2020
[86.877339] Call Trace:
[86.877344]  <TASK>
[86.877353]  dump_stack_lvl+0x91/0xf0
[86.877364]  dump_stack+0x10/0x20
[86.877369]  print_circular_bug+0x285/0x360
[86.877379]  check_noncircular+0x135/0x150
[86.877390]  __lock_acquire+0x1635/0x2810
[86.877403]  lock_acquire+0xc4/0x2f0
[86.877408]  ? stop_machine+0x1c/0x50
[86.877422]  ? __pfx_bxt_vtd_ggtt_insert_entries__cb+0x10/0x10 [i915]
[86.878173]  cpus_read_lock+0x41/0x100
[86.878182]  ? stop_machine+0x1c/0x50
[86.878191]  ? __pfx_bxt_vtd_ggtt_insert_entries__cb+0x10/0x10 [i915]
[86.878916]  stop_machine+0x1c/0x50
[86.878927]  bxt_vtd_ggtt_insert_entries__BKL+0x3b/0x60 [i915]
[86.879652]  intel_ggtt_bind_vma+0x43/0x70 [i915]
[86.880375]  __vma_bind+0x55/0x70 [i915]
[86.881133]  fence_work+0x26/0xa0 [i915]
[86.881851]  fence_notify+0xa1/0x140 [i915]
[86.882566]  __i915_sw_fence_complete+0x8f/0x270 [i915]
[86.883286]  i915_sw_fence_commit+0x39/0x60 [i915]
[86.884003]  i915_vma_pin_ww+0x462/0x1360 [i915]
[86.884756]  ? i915_vma_pin.constprop.0+0x6c/0x1d0 [i915]
[86.885513]  i915_vma_pin.constprop.0+0x133/0x1d0 [i915]
[86.886281]  initial_plane_vma+0x307/0x840 [i915]
[86.887049]  intel_initial_plane_config+0x33f/0x670 [i915]
[86.887819]  intel_display_driver_probe_nogem+0x1c6/0x260 [i915]
[86.888587]  i915_driver_probe+0x7fa/0xe80 [i915]
[86.889293]  ? mutex_unlock+0x12/0x20
[86.889301]  ? drm_privacy_screen_get+0x171/0x190
[86.889308]  ? acpi_dev_found+0x66/0x80
[86.889321]  i915_pci_probe+0xe6/0x220 [i915]
[86.890038]  local_pci_probe+0x47/0xb0
[86.890049]  pci_device_probe+0xf3/0x260
[86.890058]  really_probe+0xf1/0x3c0
[86.890067]  __driver_probe_device+0x8c/0x180
[86.890072]  driver_probe_device+0x24/0xd0
[86.890078]  __driver_attach+0x10f/0x220
[86.890083]  ? __pfx___driver_attach+0x10/0x10
[86.890088]  bus_for_each_dev+0x7f/0xe0
[86.890097]  driver_attach+0x1e/0x30
[86.890101]  bus_add_driver+0x151/0x290
[86.890107]  driver_register+0x5e/0x130
[86.890113]  __pci_register_driver+0x7d/0x90
[86.890119]  i915_pci_register_driver+0x23/0x30 [i915]
[86.890833]  i915_init+0x37/0x120 [i915]
[86.891482]  ? __pfx_i915_init+0x10/0x10 [i915]
[86.892135]  do_one_initcall+0x60/0x3f0
[86.892145]  ? __kmalloc_cache_noprof+0x33f/0x470
[86.892157]  do_init_module+0x97/0x2a0
[86.892164]  load_module+0x2c54/0x2d80
[86.892168]  ? __kernel_read+0x15c/0x300
[86.892185]  ? kernel_read_file+0x2b1/0x320
[86.892195]  init_module_from_file+0x96/0xe0
[86.892199]  ? init_module_from_file+0x96/0xe0
[86.892211]  idempotent_init_module+0x117/0x330
[86.892224]  __x64_sys_finit_module+0x77/0x100
[86.892230]  x64_sys_call+0x24de/0x2660
[86.892236]  do_syscall_64+0x91/0xe90
[86.892243]  ? irqentry_exit+0x77/0xb0
[86.892249]  ? sysvec_apic_timer_interrupt+0x57/0xc0
[86.892256]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[86.892261] RIP: 0033:0x7303e1b2725d
[86.892271] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 8b bb 0d 00 f7 d8 64 89 01 48
[86.892276] RSP: 002b:00007ffddd1fdb38 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
[86.892281] RAX: ffffffffffffffda RBX: 00005d771d88fd90 RCX: 00007303e1b2725d
[86.892285] RDX: 0000000000000000 RSI: 00005d771d893aa0 RDI: 000000000000000c
[86.892287] RBP: 00007ffddd1fdbf0 R08: 0000000000000040 R09: 00007ffddd1fdb80
[86.892289] R10: 00007303e1c03b20 R11: 0000000000000246 R12: 00005d771d893aa0
[86.892292] R13: 0000000000000000 R14: 00005d771d88f0d0 R15: 00005d771d895710
[86.892304]  </TASK>

Call asynchronous variant of dma_fence_work_commit() in that case.

v3: Provide more verbose in-line comment (Andi),
  - mention target environments in commit message.

Fixes: 7d1c261 ("drm/i915: Take reservation lock around i915_vma_pin.")
Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/14985
Cc: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
Reviewed-by: Sebastian Brzezinka <sebastian.brzezinka@intel.com>
Reviewed-by: Krzysztof Karas <krzysztof.karas@intel.com>
Acked-by: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://lore.kernel.org/r/20251023082925.351307-6-janusz.krzysztofik@linux.intel.com
(cherry picked from commit 648ef13)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
johnmeneghini pushed a commit that referenced this pull request Nov 10, 2025
Michael Chan says:

====================
bnxt_en: Bug fixes

Patches 1, 3, and 4 are bug fixes related to the FW log tracing driver
coredump feature recently added in 6.13.  Patch #1 adds the necessary
call to shutdown the FW logging DMA during PCI shutdown.  Patch #3 fixes
a possible null pointer derefernce when using early versions of the FW
with this feature.  Patch #4 adds the coredump header information
unconditionally to make it more robust.

Patch #2 fixes a possible memory leak during PTP shutdown.  Patch #5
eliminates a dmesg warning when doing devlink reload.
====================

Link: https://patch.msgid.link/20251104005700.542174-1-michael.chan@broadcom.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
johnmeneghini pushed a commit that referenced this pull request Nov 11, 2025
Add VMX exit handlers for SEAMCALL and TDCALL to inject a #UD if a non-TD
guest attempts to execute SEAMCALL or TDCALL.  Neither SEAMCALL nor TDCALL
is gated by any software enablement other than VMXON, and so will generate
a VM-Exit instead of e.g. a native #UD when executed from the guest kernel.

Note!  No unprivileged DoS of the L1 kernel is possible as TDCALL and
SEAMCALL #GP at CPL > 0, and the CPL check is performed prior to the VMX
non-root (VM-Exit) check, i.e. userspace can't crash the VM. And for a
nested guest, KVM forwards unknown exits to L1, i.e. an L2 kernel can
crash itself, but not L1.

Note #2!  The Intel® Trust Domain CPU Architectural Extensions spec's
pseudocode shows the CPL > 0 check for SEAMCALL coming _after_ the VM-Exit,
but that appears to be a documentation bug (likely because the CPL > 0
check was incorrectly bundled with other lower-priority #GP checks).
Testing on SPR and EMR shows that the CPL > 0 check is performed before
the VMX non-root check, i.e. SEAMCALL #GPs when executed in usermode.

Note #3!  The aforementioned Trust Domain spec uses confusing pseudocode
that says that SEAMCALL will #UD if executed "inSEAM", but "inSEAM"
specifically means in SEAM Root Mode, i.e. in the TDX-Module.  The long-
form description explicitly states that SEAMCALL generates an exit when
executed in "SEAM VMX non-root operation".  But that's a moot point as the
TDX-Module injects #UD if the guest attempts to execute SEAMCALL, as
documented in the "Unconditionally Blocked Instructions" section of the
TDX-Module base specification.

Cc: stable@vger.kernel.org
Cc: Kai Huang <kai.huang@intel.com>
Cc: Xiaoyao Li <xiaoyao.li@intel.com>
Cc: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Binbin Wu <binbin.wu@linux.intel.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Link: https://lore.kernel.org/r/20251016182148.69085-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
johnmeneghini pushed a commit that referenced this pull request Nov 19, 2025
…/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.18, take #3

- Only adjust the ID registers when no irqchip has been created once
  per VM run, instead of doing it once per vcpu, as this otherwise
  triggers a pretty bad conbsistency check failure in the sysreg code.

- Make sure the per-vcpu Fine Grain Traps are computed before we load
  the system registers on the HW, as we otherwise start running without
  anything set until the first preemption of the vcpu.
johnmeneghini pushed a commit that referenced this pull request Dec 1, 2025
The U-Blox EVK-M101 enumerates as 1546:0506 [1] with four FTDI interfaces:
- EVK-M101 current sensors
- EVK-M101 I2C
- EVK-M101 UART
- EVK-M101 port D

Only the third USB interface is a UART. This change lets ftdi_sio probe
the VID/PID and registers only interface #3 as a TTY, leaving the rest
available for other drivers.

[1]
usb 5-1.3: new high-speed USB device number 11 using xhci_hcd
usb 5-1.3: New USB device found, idVendor=1546, idProduct=0506, bcdDevice= 8.00
usb 5-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=0
usb 5-1.3: Product: EVK-M101
usb 5-1.3: Manufacturer: u-blox AG

Datasheet: https://content.u-blox.com/sites/default/files/documents/EVK-M10_UserGuide_UBX-21003949.pdf

Signed-off-by: Oleksandr Suvorov <cryosay@gmail.com>
Link: https://lore.kernel.org/20250926060235.3442748-1-cryosay@gmail.com/
Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
johnmeneghini pushed a commit that referenced this pull request Dec 1, 2025
For some reason, of_find_node_with_property() is creating a spinlock
recursion issue along with fwnode_count_parents(), and this issue
is making all MediaTek boards unbootable.

As of kernel v6.18-rc6, there are only three users of this function,
one of which is this driver.

Migrate away from of_find_node_with_property() by adding a local
scpsys_get_legacy_regmap_node() function, which acts similarly to
of_find_node_with_property(), and calling the former in place of
the latter.

This resolves the following spinlock recursion issue:

[    1.773979] BUG: spinlock recursion on CPU#2, kworker/u24:1/60
[    1.790485]  lock: devtree_lock+0x0/0x40, .magic: dead4ead, .owner: kworker/u24:1/60, .owner_cpu: 2
[    1.791644] CPU: 2 UID: 0 PID: 60 Comm: kworker/u24:1 Tainted: G        W           6.18.0-rc6 #3 PREEMPT
[    1.791649] Tainted: [W]=WARN
[    1.791650] Hardware name: MediaTek Genio-510 EVK (DT)
[    1.791653] Workqueue: events_unbound deferred_probe_work_func
[    1.791658] Call trace:
[    1.791659]  show_stack+0x18/0x30 (C)
[    1.791664]  dump_stack_lvl+0x68/0x94
[    1.791668]  dump_stack+0x18/0x24
[    1.791672]  spin_dump+0x78/0x88
[    1.791678]  do_raw_spin_lock+0x110/0x140
[    1.791684]  _raw_spin_lock_irqsave+0x58/0x6c
[    1.791690]  of_get_parent+0x28/0x74
[    1.791694]  of_fwnode_get_parent+0x38/0x7c
[    1.791700]  fwnode_count_parents+0x34/0xf0
[    1.791705]  fwnode_full_name_string+0x28/0x120
[    1.791710]  device_node_string+0x3e4/0x50c
[    1.791715]  pointer+0x294/0x430
[    1.791718]  vsnprintf+0x21c/0x5bc
[    1.791722]  vprintk_store+0x108/0x47c
[    1.791728]  vprintk_emit+0xc4/0x350
[    1.791732]  vprintk_default+0x34/0x40
[    1.791736]  vprintk+0x24/0x30
[    1.791740]  _printk+0x60/0x8c
[    1.791744]  of_node_release+0x154/0x194
[    1.791749]  kobject_put+0xa0/0x120
[    1.791753]  of_node_put+0x18/0x28
[    1.791756]  of_find_node_with_property+0x74/0x100
[    1.791761]  scpsys_probe+0x338/0x5e0
[    1.791765]  platform_probe+0x5c/0xa4
[    1.791770]  really_probe+0xbc/0x2ac
[    1.791774]  __driver_probe_device+0x78/0x118
[    1.791779]  driver_probe_device+0x3c/0x170
[    1.791783]  __device_attach_driver+0xb8/0x150
[    1.791788]  bus_for_each_drv+0x88/0xe8
[    1.791792]  __device_attach+0x9c/0x1a0
[    1.791796]  device_initial_probe+0x14/0x20
[    1.791801]  bus_probe_device+0xa0/0xa4
[    1.791805]  deferred_probe_work_func+0x88/0xd0
[    1.791809]  process_one_work+0x1e8/0x448
[    1.791813]  worker_thread+0x1ac/0x340
[    1.791816]  kthread+0x138/0x220
[    1.791821]  ret_from_fork+0x10/0x20

Fixes: c29345f ("pmdomain: mediatek: Refactor bus protection regmaps retrieval")
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Tested-by: Louis-Alexis Eyraud <louisalexis.eyraud@collabora.com>
Tested-by: Macpaul Lin <macpaul.lin@mediatek.com>
Reviewed-by: Macpaul Lin <macpaul.lin@mediatek.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
johnmeneghini pushed a commit that referenced this pull request Dec 22, 2025
Marc Kleine-Budde <mkl@pengutronix.de> says:

Similarly to how CAN FD reuses the bittiming logic of Classical CAN, CAN XL
also reuses the entirety of CAN FD features, and, on top of that, adds new
features which are specific to CAN XL.

A so-called 'mixed-mode' is intended to have (XL-tolerant) CAN FD nodes and
CAN XL nodes on one CAN segment, where the FD-controllers can talk CC/FD
and the XL-controllers can talk CC/FD/XL. This mixed-mode utilizes the
known error-signalling (ES) for sending CC/FD/XL frames. For CAN FD and CAN
XL the tranceiver delay compensation (TDC) is supported to use common CAN
and CAN-SIG transceivers.

The CANXL-only mode disables the error-signalling in the CAN XL controller.
This mode does not allow CC/FD frames to be sent but additionally offers a
CAN XL transceiver mode switching (TMS) to send CAN XL frames with up to
20Mbit/s data rate. The TMS utilizes a PWM configuration which is added to
the netlink interface.

Configured with CAN_CTRLMODE_FD and CAN_CTRLMODE_XL this leads to:

FD=0 XL=0 CC-only mode         (ES=1)
FD=1 XL=0 FD/CC mixed-mode     (ES=1)
FD=1 XL=1 XL/FD/CC mixed-mode  (ES=1)
FD=0 XL=1 XL-only mode         (ES=0, TMS optional)

Patch #1 print defined ctrlmode strings capitalized to increase the
readability and to be in line with the 'ip' tool (iproute2).

Patch #2 is a small clean-up which makes can_calc_bittiming() use
NL_SET_ERR_MSG() instead of netdev_err().

Patch #3 adds a check in can_dev_dropped_skb() to drop CAN FD frames
when CAN FD is turned off.

Patch #4 adds CAN_CTRLMODE_RESTRICTED. Note that contrary to the other
CAN_CTRL_MODE_XL_* that are introduced in the later patches, this control
mode is not specific to CAN XL. The nuance is that because this restricted
mode was only added in ISO 11898-1:2024, it is made mandatory for CAN XL
devices but optional for other protocols. This is why this patch is added
as a preparation before introducing the core CAN XL logic.

Patch #5 adds all the CAN XL features which are inherited from CAN FD: the
nominal bittiming, the data bittiming and the TDC.

Patch #6 add a new CAN_CTRLMODE_XL_TMS control mode which is specific to
CAN XL to enable the transceiver mode switching (TMS) in XL-only mode.

Patch #7 adds a check in can_dev_dropped_skb() to drop CAN CC/FD frames
when the CAN XL controller is in CAN XL-only mode. The introduced
can_dev_in_xl_only_mode() function also determines the error-signalling
configuration for the CAN XL controllers.

Patch #8 to #11 add the PWM logic for the CAN XL TMS mode.

Patch #12 to #14 add different default sample-points for standard CAN and
CAN SIG transceivers (with TDC) and CAN XL transceivers using PWM in the
CAN XL TMS mode.

Patch #15 add a dummy_can driver for netlink testing and debugging.

Patch #16 check CAN frame type (CC/FD/XL) when writing those frames to the
CAN_RAW socket and reject them if it's not supported by the CAN interface.

Patch #17 increase the resolution when printing the bitrate error and
round-up the value to 0.01% in the case the resolution would still provide
values which would lead to 0.00%.

Link: https://patch.msgid.link/20251126-canxl-v8-0-e7e3eb74f889@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
johnmeneghini pushed a commit that referenced this pull request Jan 5, 2026
Petr Machata says:

====================
selftests: forwarding: vxlan_bridge_1q_mc_ul: Fix flakiness

The net/forwarding/vxlan_bridge_1q_mc_ul selftest runs an overlay traffic,
forwarded over a multicast-routed VXLAN underlay. In order to determine
whether packets reach their intended destination, it uses a TC match. For
convenience, it uses a flower match, which however does not allow matching
on the encapsulated packet. So various service traffic ends up being
indistinguishable from the test packets, and ends up confusing the test. To
alleviate the problem, the test uses sleep to allow the necessary service
traffic to run and clear the channel, before running the test traffic. This
worked for a while, but lately we have nevertheless seen flakiness of the
test in the CI.

In this patchset, first generalize tc_rule_stats_get() to support u32 in
patch #1, then in patch #2 convert the test to use u32 to allow parsing
deeper into the packet, and in #3 drop the now-unnecessary sleep.
====================

Link: https://patch.msgid.link/cover.1765289566.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
johnmeneghini pushed a commit that referenced this pull request Jan 5, 2026
Fix a loop scenario of ethx:egress->ethx:egress

Example setup to reproduce:
tc qdisc add dev ethx root handle 1: drr
tc filter add dev ethx parent 1: protocol ip prio 1 matchall \
         action mirred egress redirect dev ethx

Now ping out of ethx and you get a deadlock:

[  116.892898][  T307] ============================================
[  116.893182][  T307] WARNING: possible recursive locking detected
[  116.893418][  T307] 6.18.0-rc6-01205-ge05021a829b8-dirty #204 Not tainted
[  116.893682][  T307] --------------------------------------------
[  116.893926][  T307] ping/307 is trying to acquire lock:
[  116.894133][  T307] ffff88800c122908 (&sch->root_lock_key){+...}-{3:3}, at: __dev_queue_xmit+0x2210/0x3b50
[  116.894517][  T307]
[  116.894517][  T307] but task is already holding lock:
[  116.894836][  T307] ffff88800c122908 (&sch->root_lock_key){+...}-{3:3}, at: __dev_queue_xmit+0x2210/0x3b50
[  116.895252][  T307]
[  116.895252][  T307] other info that might help us debug this:
[  116.895608][  T307]  Possible unsafe locking scenario:
[  116.895608][  T307]
[  116.895901][  T307]        CPU0
[  116.896057][  T307]        ----
[  116.896200][  T307]   lock(&sch->root_lock_key);
[  116.896392][  T307]   lock(&sch->root_lock_key);
[  116.896605][  T307]
[  116.896605][  T307]  *** DEADLOCK ***
[  116.896605][  T307]
[  116.896864][  T307]  May be due to missing lock nesting notation
[  116.896864][  T307]
[  116.897123][  T307] 6 locks held by ping/307:
[  116.897302][  T307]  #0: ffff88800b4b0250 (sk_lock-AF_INET){+.+.}-{0:0}, at: raw_sendmsg+0xb20/0x2cf0
[  116.897808][  T307]  #1: ffffffff88c839c0 (rcu_read_lock){....}-{1:3}, at: ip_output+0xa9/0x600
[  116.898138][  T307]  #2: ffffffff88c839c0 (rcu_read_lock){....}-{1:3}, at: ip_finish_output2+0x2c6/0x1ee0
[  116.898459][  T307]  #3: ffffffff88c83960 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x200/0x3b50
[  116.898782][  T307]  #4: ffff88800c122908 (&sch->root_lock_key){+...}-{3:3}, at: __dev_queue_xmit+0x2210/0x3b50
[  116.899132][  T307]  #5: ffffffff88c83960 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x200/0x3b50
[  116.899442][  T307]
[  116.899442][  T307] stack backtrace:
[  116.899667][  T307] CPU: 2 UID: 0 PID: 307 Comm: ping Not tainted 6.18.0-rc6-01205-ge05021a829b8-dirty #204 PREEMPT(voluntary)
[  116.899672][  T307] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  116.899675][  T307] Call Trace:
[  116.899678][  T307]  <TASK>
[  116.899680][  T307]  dump_stack_lvl+0x6f/0xb0
[  116.899688][  T307]  print_deadlock_bug.cold+0xc0/0xdc
[  116.899695][  T307]  __lock_acquire+0x11f7/0x1be0
[  116.899704][  T307]  lock_acquire+0x162/0x300
[  116.899707][  T307]  ? __dev_queue_xmit+0x2210/0x3b50
[  116.899713][  T307]  ? srso_alias_return_thunk+0x5/0xfbef5
[  116.899717][  T307]  ? stack_trace_save+0x93/0xd0
[  116.899723][  T307]  _raw_spin_lock+0x30/0x40
[  116.899728][  T307]  ? __dev_queue_xmit+0x2210/0x3b50
[  116.899731][  T307]  __dev_queue_xmit+0x2210/0x3b50

Fixes: 178ca30 ("Revert "net/sched: Fix mirred deadlock on device recursion"")
Tested-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20251210162255.1057663-1-jhs@mojatatu.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
johnmeneghini pushed a commit that referenced this pull request Jan 5, 2026
… to macb_open()

In the non-RT kernel, local_bh_disable() merely disables preemption,
whereas it maps to an actual spin lock in the RT kernel. Consequently,
when attempting to refill RX buffers via netdev_alloc_skb() in
macb_mac_link_up(), a deadlock scenario arises as follows:

   WARNING: possible circular locking dependency detected
   6.18.0-08691-g2061f18ad76e #39 Not tainted
   ------------------------------------------------------
   kworker/0:0/8 is trying to acquire lock:
   ffff00080369bbe0 (&bp->lock){+.+.}-{3:3}, at: macb_start_xmit+0x808/0xb7c

   but task is already holding lock:
   ffff000803698e58 (&queue->tx_ptr_lock){+...}-{3:3}, at: macb_start_xmit
   +0x148/0xb7c

   which lock already depends on the new lock.

   the existing dependency chain (in reverse order) is:

   -> #3 (&queue->tx_ptr_lock){+...}-{3:3}:
          rt_spin_lock+0x50/0x1f0
          macb_start_xmit+0x148/0xb7c
          dev_hard_start_xmit+0x94/0x284
          sch_direct_xmit+0x8c/0x37c
          __dev_queue_xmit+0x708/0x1120
          neigh_resolve_output+0x148/0x28c
          ip6_finish_output2+0x2c0/0xb2c
          __ip6_finish_output+0x114/0x308
          ip6_output+0xc4/0x4a4
          mld_sendpack+0x220/0x68c
          mld_ifc_work+0x2a8/0x4f4
          process_one_work+0x20c/0x5f8
          worker_thread+0x1b0/0x35c
          kthread+0x144/0x200
          ret_from_fork+0x10/0x20

   -> #2 (_xmit_ETHER#2){+...}-{3:3}:
          rt_spin_lock+0x50/0x1f0
          sch_direct_xmit+0x11c/0x37c
          __dev_queue_xmit+0x708/0x1120
          neigh_resolve_output+0x148/0x28c
          ip6_finish_output2+0x2c0/0xb2c
          __ip6_finish_output+0x114/0x308
          ip6_output+0xc4/0x4a4
          mld_sendpack+0x220/0x68c
          mld_ifc_work+0x2a8/0x4f4
          process_one_work+0x20c/0x5f8
          worker_thread+0x1b0/0x35c
          kthread+0x144/0x200
          ret_from_fork+0x10/0x20

   -> #1 ((softirq_ctrl.lock)){+.+.}-{3:3}:
          lock_release+0x250/0x348
          __local_bh_enable_ip+0x7c/0x240
          __netdev_alloc_skb+0x1b4/0x1d8
          gem_rx_refill+0xdc/0x240
          gem_init_rings+0xb4/0x108
          macb_mac_link_up+0x9c/0x2b4
          phylink_resolve+0x170/0x614
          process_one_work+0x20c/0x5f8
          worker_thread+0x1b0/0x35c
          kthread+0x144/0x200
          ret_from_fork+0x10/0x20

   -> #0 (&bp->lock){+.+.}-{3:3}:
          __lock_acquire+0x15a8/0x2084
          lock_acquire+0x1cc/0x350
          rt_spin_lock+0x50/0x1f0
          macb_start_xmit+0x808/0xb7c
          dev_hard_start_xmit+0x94/0x284
          sch_direct_xmit+0x8c/0x37c
          __dev_queue_xmit+0x708/0x1120
          neigh_resolve_output+0x148/0x28c
          ip6_finish_output2+0x2c0/0xb2c
          __ip6_finish_output+0x114/0x308
          ip6_output+0xc4/0x4a4
          mld_sendpack+0x220/0x68c
          mld_ifc_work+0x2a8/0x4f4
          process_one_work+0x20c/0x5f8
          worker_thread+0x1b0/0x35c
          kthread+0x144/0x200
          ret_from_fork+0x10/0x20

   other info that might help us debug this:

   Chain exists of:
     &bp->lock --> _xmit_ETHER#2 --> &queue->tx_ptr_lock

    Possible unsafe locking scenario:

          CPU0                    CPU1
          ----                    ----
     lock(&queue->tx_ptr_lock);
                                  lock(_xmit_ETHER#2);
                                  lock(&queue->tx_ptr_lock);
     lock(&bp->lock);

    *** DEADLOCK ***

   Call trace:
    show_stack+0x18/0x24 (C)
    dump_stack_lvl+0xa0/0xf0
    dump_stack+0x18/0x24
    print_circular_bug+0x28c/0x370
    check_noncircular+0x198/0x1ac
    __lock_acquire+0x15a8/0x2084
    lock_acquire+0x1cc/0x350
    rt_spin_lock+0x50/0x1f0
    macb_start_xmit+0x808/0xb7c
    dev_hard_start_xmit+0x94/0x284
    sch_direct_xmit+0x8c/0x37c
    __dev_queue_xmit+0x708/0x1120
    neigh_resolve_output+0x148/0x28c
    ip6_finish_output2+0x2c0/0xb2c
    __ip6_finish_output+0x114/0x308
    ip6_output+0xc4/0x4a4
    mld_sendpack+0x220/0x68c
    mld_ifc_work+0x2a8/0x4f4
    process_one_work+0x20c/0x5f8
    worker_thread+0x1b0/0x35c
    kthread+0x144/0x200
    ret_from_fork+0x10/0x20

Notably, invoking the mog_init_rings() callback upon link establishment
is unnecessary. Instead, we can exclusively call mog_init_rings() within
the ndo_open() callback. This adjustment resolves the deadlock issue.
Furthermore, since MACB_CAPS_MACB_IS_EMAC cases do not use mog_init_rings()
when opening the network interface via at91ether_open(), moving
mog_init_rings() to macb_open() also eliminates the MACB_CAPS_MACB_IS_EMAC
check.

Fixes: 633e98a ("net: macb: use resolved link config in mac_link_up()")
Cc: stable@vger.kernel.org
Suggested-by: Kevin Hao <kexin.hao@windriver.com>
Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com>
Link: https://patch.msgid.link/20251222015624.1994551-1-xiaolei.wang@windriver.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
johnmeneghini pushed a commit that referenced this pull request Jan 14, 2026
The GPIO controller is configured as non-sleeping but it uses generic
pinctrl helpers which use a mutex for synchronization.

This can cause the following lockdep splat with shared GPIOs enabled on
boards which have multiple devices using the same GPIO:

BUG: sleeping function called from invalid context at
kernel/locking/mutex.c:591
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 12, name:
kworker/u16:0
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
6 locks held by kworker/u16:0/12:
  #0: ffff0001f0018d48 ((wq_completion)events_unbound#2){+.+.}-{0:0},
at: process_one_work+0x18c/0x604
  #1: ffff8000842dbdf0 (deferred_probe_work){+.+.}-{0:0}, at:
process_one_work+0x1b4/0x604
  #2: ffff0001f18498f8 (&dev->mutex){....}-{4:4}, at:
__device_attach+0x38/0x1b0
  #3: ffff0001f75f1e90 (&gdev->srcu){.+.?}-{0:0}, at:
gpiod_direction_output_raw_commit+0x0/0x360
  #4: ffff0001f46e3db8 (&shared_desc->spinlock){....}-{3:3}, at:
gpio_shared_proxy_direction_output+0xd0/0x144 [gpio_shared_proxy]
  #5: ffff0001f180ee90 (&gdev->srcu){.+.?}-{0:0}, at:
gpiod_direction_output_raw_commit+0x0/0x360
irq event stamp: 81450
hardirqs last  enabled at (81449): [<ffff8000813acba4>]
_raw_spin_unlock_irqrestore+0x74/0x78
hardirqs last disabled at (81450): [<ffff8000813abfb8>]
_raw_spin_lock_irqsave+0x84/0x88
softirqs last  enabled at (79616): [<ffff8000811455fc>]
__alloc_skb+0x17c/0x1e8
softirqs last disabled at (79614): [<ffff8000811455fc>]
__alloc_skb+0x17c/0x1e8
CPU: 2 UID: 0 PID: 12 Comm: kworker/u16:0 Not tainted
6.19.0-rc4-next-20260105+ #11975 PREEMPT
Hardware name: Hardkernel ODROID-M1 (DT)
Workqueue: events_unbound deferred_probe_work_func
Call trace:
  show_stack+0x18/0x24 (C)
  dump_stack_lvl+0x90/0xd0
  dump_stack+0x18/0x24
  __might_resched+0x144/0x248
  __might_sleep+0x48/0x98
  __mutex_lock+0x5c/0x894
  mutex_lock_nested+0x24/0x30
  pinctrl_get_device_gpio_range+0x44/0x128
  pinctrl_gpio_direction+0x3c/0xe0
  pinctrl_gpio_direction_output+0x14/0x20
  rockchip_gpio_direction_output+0xb8/0x19c
  gpiochip_direction_output+0x38/0x94
  gpiod_direction_output_raw_commit+0x1d8/0x360
  gpiod_direction_output_nonotify+0x7c/0x230
  gpiod_direction_output+0x34/0xf8
  gpio_shared_proxy_direction_output+0xec/0x144 [gpio_shared_proxy]
  gpiochip_direction_output+0x38/0x94
  gpiod_direction_output_raw_commit+0x1d8/0x360
  gpiod_direction_output_nonotify+0x7c/0x230
  gpiod_configure_flags+0xbc/0x480
  gpiod_find_and_request+0x1a0/0x574
  gpiod_get_index+0x58/0x84
  devm_gpiod_get_index+0x20/0xb4
  devm_gpiod_get_optional+0x18/0x30
  rockchip_pcie_probe+0x98/0x380
  platform_probe+0x5c/0xac
  really_probe+0xbc/0x298

Fixes: 936ee26 ("gpio/rockchip: add driver for rockchip gpio")
Cc: stable@vger.kernel.org
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Closes: https://lore.kernel.org/all/d035fc29-3b03-4cd6-b8ec-001f93540bc6@samsung.com/
Acked-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20260106090011.21603-1-bartosz.golaszewski@oss.qualcomm.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
johnmeneghini pushed a commit that referenced this pull request Jan 22, 2026
…/pub/scm/linux/kernel/git/mkl/linux-can

Marc Kleine-Budde says:

====================
pull-request: can 2026-01-15

this is a pull request of 4 patches for net/main, it super-seeds the
"can 2026-01-14" pull request. The dev refcount leak in patch #3 is
fixed.

The first 3 patches are by Oliver Hartkopp and revert the approach to
instantly reject unsupported CAN frames introduced in
net-next-for-v6.19 and replace it by placing the needed data into the
CAN specific ml_priv.

The last patch is by Tetsuo Handa and fixes a J1939 refcount leak for
j1939_session in session deactivation upon receiving the second RTS.

linux-can-fixes-for-6.19-20260115

* tag 'linux-can-fixes-for-6.19-20260115' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can:
  net: can: j1939: j1939_xtp_rx_rts_session_active(): deactivate session upon receiving the second rts
  can: raw: instantly reject disabled CAN frames
  can: propagate CAN device capabilities via ml_priv
  Revert "can: raw: instantly reject unsupported CAN frames"
====================

Link: https://patch.msgid.link/20260115090603.1124860-1-mkl@pengutronix.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
johnmeneghini pushed a commit that referenced this pull request Jan 22, 2026
Patch series "mm/hugetlb: fixes for PMD table sharing (incl.  using
mmu_gather)", v3.

One functional fix, one performance regression fix, and two related
comment fixes.

I cleaned up my prototype I recently shared [1] for the performance fix,
deferring most of the cleanups I had in the prototype to a later point. 
While doing that I identified the other things.

The goal of this patch set is to be backported to stable trees "fairly"
easily. At least patch #1 and #4.

Patch #1 fixes hugetlb_pmd_shared() not detecting any sharing
Patch #2 + #3 are simple comment fixes that patch #4 interacts with.
Patch #4 is a fix for the reported performance regression due to excessive
IPI broadcasts during fork()+exit().

The last patch is all about TLB flushes, IPIs and mmu_gather.
Read: complicated

There are plenty of cleanups in the future to be had + one reasonable
optimization on x86. But that's all out of scope for this series.

Runtime tested, with a focus on fixing the performance regression using
the original reproducer [2] on x86.


This patch (of 4):

We switched from (wrongly) using the page count to an independent shared
count.  Now, shared page tables have a refcount of 1 (excluding
speculative references) and instead use ptdesc->pt_share_count to identify
sharing.

We didn't convert hugetlb_pmd_shared(), so right now, we would never
detect a shared PMD table as such, because sharing/unsharing no longer
touches the refcount of a PMD table.

Page migration, like mbind() or migrate_pages() would allow for migrating
folios mapped into such shared PMD tables, even though the folios are not
exclusive.  In smaps we would account them as "private" although they are
"shared", and we would be wrongly setting the PM_MMAP_EXCLUSIVE in the
pagemap interface.

Fix it by properly using ptdesc_pmd_is_shared() in hugetlb_pmd_shared().

Link: https://lkml.kernel.org/r/20251223214037.580860-1-david@kernel.org
Link: https://lkml.kernel.org/r/20251223214037.580860-2-david@kernel.org
Link: https://lore.kernel.org/all/8cab934d-4a56-44aa-b641-bfd7e23bd673@kernel.org/ [1]
Link: https://lore.kernel.org/all/8cab934d-4a56-44aa-b641-bfd7e23bd673@kernel.org/ [2]
Fixes: 59d9094 ("mm: hugetlb: independent PMD page table shared count")
Signed-off-by: David Hildenbrand (Red Hat) <david@kernel.org>
Reviewed-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Tested-by: Lance Yang <lance.yang@linux.dev>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: Oscar Salvador <osalvador@suse.de>
Cc: Liu Shixin <liushixin2@huawei.com>
Cc: Uschakow, Stanislav" <suschako@amazon.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

None yet

Projects

None yet

Development

Successfully merging this pull request may close these issues.

8 participants