Thomas Gleixner [Fri, 29 May 2026 20:00:24 +0000 (22:00 +0200)]
timekeeping: Add CLOCK_AUX support for ktime_get_snapshot_id()
Now that all users are converted it's possible to enable snapshotting of
CLOCK_AUX time. The underlying clocksource is the same as for all other
CLOCK variants.
Signed-off-by: Thomas Gleixner <tglx@kernel.org> Tested-by: Arthur Kiyanovski <akiyano@amazon.com> Reviewed-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Link: https://patch.msgid.link/20260529195557.380601005@kernel.org
All users are converted over to ktime_get_snapshot_id() and
system_time_snapshot::systime and ::monoraw.
Remove the leftovers.
Signed-off-by: Thomas Gleixner <tglx@kernel.org> Tested-by: David Woodhouse <dwmw@amazon.co.uk> Tested-by: Arthur Kiyanovski <akiyano@amazon.com> Reviewed-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Link: https://patch.msgid.link/20260529195557.330029635@kernel.org
Thomas Gleixner [Fri, 29 May 2026 20:00:16 +0000 (22:00 +0200)]
ptp: ptp_vmclock: Convert to ktime_get_snapshot_id()
ktime_get_snapshot() is replaced by ktime_get_snapshot_id() which allows to
request a particular CLOCK ID to be captured along with the clocksource
counter.
Convert vmclock over and use the new system_time_snapshot::systime field,
which holds the system timestamp selected by the CLOCK ID argument.
No functional change intended.
Signed-off-by: Thomas Gleixner <tglx@kernel.org> Tested-by: David Woodhouse <dwmw@amazon.co.uk> Tested-by: Arthur Kiyanovski <akiyano@amazon.com> Reviewed-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Link: https://patch.msgid.link/20260529195557.281425262@kernel.org
Thomas Gleixner [Fri, 29 May 2026 20:00:12 +0000 (22:00 +0200)]
KVM: arm64: Use ktime_get_snapshot_id() to snapshot CLOCK_REALTIME
ktime_get_snapshot() is replaced by ktime_get_snapshot_id() which allows to
request a particular CLOCK ID to be captured along with the clocksource
counter.
Convert the usage in kvm_get_ptp_time() over and use the new
system_time_snapshot::systime field, which holds the system timestamp
selected by the CLOCK ID argument.
No functional change intended.
Signed-off-by: Thomas Gleixner <tglx@kernel.org> Tested-by: Arthur Kiyanovski <akiyano@amazon.com> Reviewed-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Acked-by: Marc Zyngier <maz@kernel.org> Link: https://patch.msgid.link/20260529195557.225399927@kernel.org
Thomas Gleixner [Fri, 29 May 2026 20:00:08 +0000 (22:00 +0200)]
KVM: arm64: Use ktime_get_snapshot_id() to retrieve CLOCK_BOOTTIME
ktime_get_snapshot() is replaced by ktime_get_snapshot_id() which allows to
request a particular CLOCK ID to be captured along with the clocksource
counter.
Convert the tracing mechanism over and use the new
system_time_snapshot::systime field, which holds the system timestamp
selected by the CLOCK ID argument.
No functional change intended.
Signed-off-by: Thomas Gleixner <tglx@kernel.org> Tested-by: Arthur Kiyanovski <akiyano@amazon.com> Reviewed-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Acked-by: Marc Zyngier <maz@kernel.org> Acked-by: Vincent Donnefort <vdonnefort@google.com> Link: https://patch.msgid.link/20260529195557.174373054@kernel.org
Eva Kurchatova [Wed, 3 Jun 2026 15:31:42 +0000 (18:31 +0300)]
tracing: Fix CFI violation in probestub being called by tprobes
The probestub is a function to allow tprobes to hook to a tracepoint to
gain access to its parameters. The function itself is only referenced by
the tracepoint structure which lives in the __tracepoint section. objtool
explicitly ignores that section and when processing functions in the
kernel, if it detects one that has no references it will seal it to have
its ENDBR stripped on boot up.
This means when a tprobe is attached to the sched_wakeup tracepoint, when it
is triggered it will call __probestub_sched_wakeup and due to the missing
ENDBR on a CFI-enabled machine it will take a #CP exception.
Fix this by adding CFI_NOSEAL annotation to probestub declaration.
Cc: stable@vger.kernel.org Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Link: https://patch.msgid.link/20260603153147.573589-1-eva.kurchatova@virtuozzo.com Fixes: d5173f753750 ("objtool: Exclude __tracepoints data from ENDBR checks") Signed-off-by: Eva Kurchatova <eva.kurchatova@virtuozzo.com>
[ Updated change log ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Nilay Shroff [Sat, 16 May 2026 18:36:55 +0000 (00:06 +0530)]
nvme: export controller reconnect event count via sysfs
When an NVMe-oF link goes down, the driver attempts to recover the
connection by repeatedly reconnecting to the remote controller at
configured intervals. A maximum number of reconnect attempts is also
configured, after which recovery stops and the controller is removed
if the connection cannot be re-established.
The driver maintains a counter, nr_reconnects, which is incremented on
each reconnect attempt. However if in case the reconnect is successful
then this counter reset to zero. Moreover, currently, this counter is
only reported via kernel log messages and is not exposed to userspace.
Since dmesg is a circular buffer, this information may be lost over
time.
So introduce a new accumulator which accumulates nr_reconnect attempts
and also expose this accumulator per-fabric ctrl via a new sysfs
attribute reconnect_count, under diag attribute grroup to provide
persistent visibility into the number of reconnect attempts made by the
host. This information can help users diagnose unstable links or
connectivity issues. Furthermore, this sysfs attribute is also writable
so user may reset it to zero, if needed.
The reconnect_count can also be consumed by monitoring tools such as
nvme-top to improve controller-level observability.
Nilay Shroff [Sat, 16 May 2026 18:36:54 +0000 (00:06 +0530)]
nvme: export controller reset event count via sysfs
The NVMe controller transitions into the RESETTING state during error
recovery, link instability, firmware activation, or when a reset is
explicitly triggered by the user.
Expose a per-ctrl sysfs attribute reset_count, under diag attribute
group to provide visibility into these RESETTING state transitions.
Observing the frequency of reset events can help users identify issues
such as PCIe errors or unstable fabric links. This counter is also
writable thus allowing user to reset its value, if needed.
This counter can also be consumed by monitoring tools such as nvme-top
to improve controller-level observability.
Nilay Shroff [Sat, 16 May 2026 18:36:53 +0000 (00:06 +0530)]
nvme: export I/O failure count when no path is available via sysfs
When I/O is submitted to the NVMe namespace head and no available path
can handle the request, the driver fails the I/O immediately. Currently,
such failures are only reported via kernel log messages, which may be
lost over time since dmesg is a circular buffer.
Add a new ns-head sysfs counter io_fail_no_available_path_count, under
diag attribute group to expose the number of I/Os that failed due to the
absence of an available path. This provides persistent visibility into
path-related I/O failures and can help users diagnose the cause of I/O
errors. This counter is also writable and so user may reset its value,
if needed.
This counter can also be consumed by monitoring tools such as nvme-top.
Nilay Shroff [Sat, 16 May 2026 18:36:52 +0000 (00:06 +0530)]
nvme: export I/O requeue count when no path is usable via sysfs
When the NVMe namespace head determines that there is no currently
available path to handle I/O (for example, while a controller is
resetting/connecting or due to a transient link failure), incoming
I/Os are added to the requeue list.
Currently, there is no visibility into how many I/Os have been requeued
in this situation. Add a new ns-head sysfs counter
io_requeue_no_usable_path_count, under diag attribute group to expose
the number of I/Os that were requeued due to the absence of an available
path. This counter is also writable thus allowing user to reset it, if
needed.
This statistic can help users understand I/O slowdowns or stalls caused
by temporary path unavailability, and can be consumed by monitoring
tools such as nvme-top for real-time observability.
Nilay Shroff [Sat, 16 May 2026 18:36:51 +0000 (00:06 +0530)]
nvme: export command error counters via sysfs
When an NVMe command completes with an error status, the driver
logs the error to the kernel log. However, these messages may be
lost or overwritten over time since dmesg is a circular buffer.
Expose per-path and ctrl sysfs attribute command_error_count, under
diag attribute group to provide persistent visibility into error
occurrences. This allows users to observe the total number of commands
that have failed on a given path over time, which can be useful for
diagnosing path health and stability.
This attribute is both readable and writable thus allowing user to reset
these counters. These counters can also be consumed by observability
tools such as nvme-top to provide additional insight into NVMe error
behavior.
Nilay Shroff [Sat, 16 May 2026 18:36:50 +0000 (00:06 +0530)]
nvme: export multipath failover count via sysfs
When an NVMe command completes with a path-specific error, the NVMe
driver may retry the command on an alternate controller or path if one
is available. These failover events indicate that I/O was redirected
away from the original path.
Currently, the number of times requests are failed over to another
available path is not visible to userspace. Exposing this information
can be useful for diagnosing path health and stability.
Export per-path sysfs attribute "multipath_failover_count" under diag
attribute group. This attribute is both readable and writable and thus
allowing user to reset the counter. This counter can be consumed by
monitoring tools such as nvme-top to help identify paths that
consistently trigger failovers under load.
Nilay Shroff [Sat, 16 May 2026 18:36:49 +0000 (00:06 +0530)]
nvme: export command retry count via sysfs
When Advanced Command Retry Enable (ACRE) is configured, a controller
may interrupt command execution and return a completion status
indicating command interrupted with the DNR bit cleared. In this case,
the driver retries the command based on the Command Retry Delay (CRD)
value provided in the completion status.
Currently, these command retries are handled entirely within the NVMe
driver and are not visible to userspace. As a result, there is no
observability into retry behavior, which can be a useful diagnostic
signal.
Expose a per-namespace sysfs attribute command_retries_count, under
diag attribute group to provide visibility into retry activity. This
information can help identify controller-side congestion under load
and enables comparison across paths in multipath setups (for example,
detecting cases where one path experiences significantly more retries
than another under identical workloads).
This exported metric is intended for diagnostics and monitoring tools
such as nvme-top, and does not change command retry behavior. A new
sysfs attribute named "command_retries_count" is added for this purpose.
This attribute is both readable as well as writable. So user could
reset this counter if needed.
Reinette Chatre [Thu, 4 Jun 2026 03:38:47 +0000 (20:38 -0700)]
cpu: Add lockdep_is_cpus_held()/lockdep_is_cpus_write_held() stubs for !CONFIG_HOTPLUG_CPU
lockdep_is_cpus_held() and lockdep_is_cpus_write_held() are undefined when
!CONFIG_HOTPLUG_CPU. This is ok because their few callers protect the calls
with a "if (IS_ENABLED(CONFIG_HOTPLUG_CPU) ..." check.
It is error prone to require callers to protect lockdep_is_cpus_held()
and lockdep_is_cpus_write_held() with an IS_ENABLED(CONFIG_HOTPLUG_CPU)
check while the custom for equivalent functions, for example the more
prevalent lockdep_is_held(), is to not require similar protection.
It is also inconsistent with CPU hotplug lockdep code self since related
call lockdep_assert_cpus_held() does not require protection.
Create stubs for lockdep_is_cpus_held() and lockdep_is_cpus_write_held()
that returns 1 (LOCK_STATE_UNKNOWN/LOCK_STATE_HELD) when !CONFIG_HOTPLUG_CPU.
This makes the CPU hotplug lockdep checks consistent while following
existing lockdep custom. Drop the "extern" from the function declaration
as part of the move to match kernel coding style.
Keep the IS_ENABLED(CONFIG_HOTPLUG_CPU) checks in existing users since
removing them would change the logic of these expressions.
Tomas Glozar [Tue, 2 Jun 2026 12:55:06 +0000 (14:55 +0200)]
rtla: Fix parsing of multi-character short options
A bug was reported where the parsing of multi-character short options,
be it a short option with an argument specified without space (e.g.
"-p100") or multiple short options in one argument (e.g. -un), ignores
options specific to individual tools.
Furthermore, if the rest of the option is supposed to be an argument, it
gets reinterpreted as a string of options. For example, -p100 gets
interpreted as -100, which is due to hackish implementation read as
--no-thread --no-irq --no-irq with timerlat hist, causing rtla to error
out:
$ rtla timerlat hist -p100
no-irq and no-thread set, there is nothing to do here
This behavior is caused by getopt_long() being called twice on each
argument, once in common_parse_options(), once in [tool]_parse_args():
- common_parse_options() calls getopt_long() with an array of options
common for all rtla tools, while suppressing errors (opterr = 0).
- If the option fails to parse, common_parse_options() returns 0.
- If 0 is returned from common_parse_options(), [tool]_parse_args()
calls getopt_long() again, with its own set of options.
* [tool] means one of {osnoise,timerlat}_{top,hist}
At least in glibc, getopt_long() increments its internal nextchar
variable even if the option is not recognized. That means that in the
case of "-p100", common_parse_options() sets nextchar pointing to '1',
and timerlat_hist_parse_args() sees '1', not 'p'; the same then repeats
for the first and second '0'.
As there is no way to restore the correct internal state of
getopt_long() reliably, fix the issue by merging the common options back
to the longopt array and option string of the [tool]_parse_args()
functions using a macro; only the switch part is left in the original
function, which is renamed to set_common_option().
Antoine Tenart [Fri, 29 May 2026 14:47:00 +0000 (16:47 +0200)]
geneve: fix length used in GRO hint UDP checksum adjustment
In geneve_post_decap_hint the length used for adjusting the UDP checksum
should be 'skb->len - gro_hint->nested_tp_offset' (UDP length) instead
of 'skb->len - gro_hint->nested_nh_offset' (IP length).
Fixes: fd0dd796576e ("geneve: use GRO hint option in the RX path") Cc: Paolo Abeni <pabeni@redhat.com> Reported-by: Sashiko <sashiko-bot@kernel.org> Closes: https://sashiko.dev/#/patchset/20260521131436.748832-1-jhs%40mojatatu.com Signed-off-by: Antoine Tenart <atenart@kernel.org> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20260529144713.780938-1-atenart@kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Merge patch series "Remove b_end_io from struct buffer_head"
Matthew Wilcox (Oracle) <willy@infradead.org> says:
There are four benefits to this patchset. First, it removes an
indirect function call from the completion path. Instead of setting
bio->bi_end_io to end_bio_bh_io_sync() which then calls bh->b_end_io(),
we set bio->bi_end_io to the appropriate completion handler, replacing
two indirect function calls with one.
Second, there is a slight security advantage to this. It is one fewer
function pointer in the middle of a writable data structure that can
be corrupted. Third, it shrinks struct buffer_head from 104 bytes to 96
bytes, allowing for appropriximately 7% reduction in the amount of memory
used by buffer_heads (or, alternatively, allows 7% more buffer_heads to
be cached in the same amount of memory). Fourth, it removes some
atomic operations as the buffer refcount is no longer incremented before
calling the end_io handler.
I've run ext4 through its paces, and everything seems OK. I've only
compiled ocfs2/gfs2/nilfs/md-bitmap. Hopefully the maintainers can give
this series a try. I'm sending the entire series to linux-fsdevel
and cc'ing the fs-specific mailing lists for the fs-specific patches.
* patches from https://patch.msgid.link/20260528173150.1093780-1-willy@infradead.org: (34 commits)
buffer: Remove end_buffer_write_sync()
buffer: Change calling convention for end_buffer_read_sync()
buffer: Remove b_end_io
buffer: Remove submit_bh()
md-bitmap: Convert read_file_page and write_file_page to bh_submit()
nilfs2: Convert nilfs_mdt_submit_block to bh_submit()
nilfs2: Convert nilfs_gccache_submit_read_data to bh_submit()
nilfs2: Convert nilfs_btnode_submit_block to bh_submit()
buffer: Remove mark_buffer_async_write()
gfs2: Convert gfs2_aspace_write_folio to bh_submit()
gfs2: Remove use of b_end_io in gfs2_meta_read_endio()
gfs2: Convert gfs2_dir_readahead to bh_submit()
gfs2: Convert gfs2_metapath_ra to bh_submit()
ocfs2: Convert ocfs2_write_super_or_backup to bh_submit()
ocfs2: Convert ocfs2_read_blocks to bh_submit()
ocfs2: Convert ocfs2_read_block to bh_submit()
ocfs2: Convert ocfs2_write_block to bh_submit()
jbd2: Convert jbd2_write_superblock() to bh_submit()
jbd2: Convert journal commit to bh_submit()
ext4: Convert ext4_commit_super() to bh_submit()
...
buffer: Change calling convention for end_buffer_read_sync()
Unify end_buffer_read_sync() and __end_buffer_read_notouch()
by requiring the caller put the refcount on the buffer. The only caller
is in the gfs2_meta_read() path, and there we can put the refcount
after locking the buffer.
This shrinks buffer_head by 8 bytes, letting us pack more buffer heads
per slab. With a Debian config, it shrinks from 104 bytes to 96 bytes
which is 42 objects per 4KiB page rather than 39, a 7% reduction in the
amount of memory used.
There are no more callers of this function, so delete it.
end_buffer_async_write() then has only one caller left, so
inline it into bh_end_async_write().
Avoid an extra indirect function call by using bh_submit() instead of
submit_bh(). Also simplify the control flow now that the buffer
refcount is not put by bh_end_read().
Avoid an extra indirect function call by using bh_submit() instead
of submit_bh(). Also simplify the control flow now that the buffer
refcount is not put by bh_end_read().
ocfs2: Convert ocfs2_write_super_or_backup to bh_submit()
Avoid an extra indirect function call and changing the buffer refcount
by using bh_submit() instead of submit_bh().
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Link: https://patch.msgid.link/20260528173150.1093780-22-willy@infradead.org Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: ocfs2-devel@lists.linux.dev Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Avoid an extra indirect function call and changing the buffer refcount
by using bh_submit() instead of submit_bh().
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Link: https://patch.msgid.link/20260528173150.1093780-21-willy@infradead.org Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: ocfs2-devel@lists.linux.dev Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Avoid an extra indirect function call and changing the buffer refcount
by using bh_submit() instead of submit_bh().
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Link: https://patch.msgid.link/20260528173150.1093780-20-willy@infradead.org Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: ocfs2-devel@lists.linux.dev Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Avoid an extra indirect function call and changing the buffer
refcount by using bh_submit() instead of submit_bh().
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Link: https://patch.msgid.link/20260528173150.1093780-19-willy@infradead.org Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: ocfs2-devel@lists.linux.dev Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Avoid an extra indirect function call by using bh_submit()
instead of submit_bh() in journal_submit_commit_record()
and jbd2_journal_commit_transaction(). These both use
journal_end_buffer_io_sync(), so it's more straightforward to do them
both at once.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Link: https://patch.msgid.link/20260528173150.1093780-17-willy@infradead.org Acked-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz> Cc: linux-ext4@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Avoid an extra indirect function call and changing the buffer refcount
by converting ext4_end_bitmap_read() from bh_end_io_t to bio_end_io_t
and calling bh_submit().
buffer: Convert __block_write_full_folio to __bh_submit()
Avoid an extra indirect function call by using __bh_submit() instead
of submit_bh_wbc(). Since there is only one caller of submit_bh_wbc()
left, inline it into submit_bh().
buffer: Convert block_read_full_folio to bh_submit()
Avoid an extra indirect function call by using bh_submit() instead of
submit_bh(). Since mark_buffer_async_read() would collapse to a single
function call, inline it into block_read_full_folio() along with its
extensive comment. Convert end_buffer_async_read_io() to
bh_end_async_read().
Avoid an extra indirect function call and changing the buffer refcount
by using bh_submit() instead of submit_bh().
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Link: https://patch.msgid.link/20260528173150.1093780-10-willy@infradead.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
buffer: Add bh_end_read(), bh_end_write() and bh_end_async_write()
These are the bio_end_io_t versions of end_buffer_read_sync(),
end_buffer_write_sync() and end_buffer_async_write(). They do not
contain a put_bh() call as it is no longer necessary.
All callers of mark_buffer_async_write_endio() pass
end_buffer_async_write, so we can inline mark_buffer_async_write_endio()
into mark_buffer_async_write() and just call that instead.
bh_submit() takes a bio_end_io allowing users to avoid the indirect
function call through bh->b_end_io, and eventually allowing us to remove
bh->b_end_io.
Nam Cao [Tue, 2 Jun 2026 17:51:46 +0000 (19:51 +0200)]
eventpoll: Fix epoll_wait() report false negative
ep_events_available() checks for available events by looking at
ep->rdllist and ep_is_scanning(). However, this is done without a lock
and can report false negative if ep_start_scan() or ep_done_scan() are
executed by another task concurrently. For example:
_________________________________________________________________________
|ep_start_scan()
| list_splice_init(&ep->rdllist, ...)
ep_events_available() |
!list_empty_careful(&ep->rdllist)|
|| ep_is_scanning(ep) |
| ep_enter_scan(ep)
___________________________________|_____________________________________
In the above examples, ep_events_available() sees no event despite
events being available. In case epoll_wait() is called with timeout=0,
epoll_wait() will wrongly return "no event" to user.
Introduce a sequence lock to resolve this issue.
Measuring the time consumption of 10 million loop iterations doing
epoll_wait(), the following performance drop is observed:
timeout #event before after diff
0ms 0 3727ms 3974ms +6.6%
0ms 1 8099ms 9134ms +13%
1ms 1 13525ms 13586ms +0.45%
Considering the use case of epoll_wait() (wait for events, do something
with the events, repeat), it should only contribute to a small portion of
user's CPU consumption. Therefore this performance drop is not alarming.
Nam Cao [Tue, 2 Jun 2026 17:51:45 +0000 (19:51 +0200)]
selftests/eventpoll: Add test for multiple waiters
Add a test whichs creates 64 threads who all epoll_wait() on the same
eventpoll. The source eventfd is written but never read, therefore all the
threads should always see an EPOLLIN event.
This test fails because of a kernel bug, which will be fixed by a follow-up
commit.
Cássio Gabriel [Thu, 4 Jun 2026 04:48:14 +0000 (01:48 -0300)]
ALSA: seq: oss: Use scoped cleanup for temporary MIDI use lock
The OSS sequencer write and out-of-band paths may receive a temporary
snd_use_lock_t reference from snd_seq_oss_process_event(). This was added
to keep MIDI device data alive until events with embedded SysEx data are
dispatched.
Use a scoped cleanup helper for that temporary reference. This keeps the
lifetime rule local to the variable declaration and avoids future missing
snd_use_lock_free() paths if these event handling paths gain more exits.
Cássio Gabriel [Thu, 4 Jun 2026 04:48:13 +0000 (01:48 -0300)]
ALSA: core: Add scoped cleanup helper for card references
Several ALSA paths acquire temporary card references with snd_card_ref()
and release them manually with snd_card_unref(). control_led.c already
defines a local cleanup helper for this pattern, while other core paths
still open-code the release.
Move the helper to the common ALSA core header and use it in control-layer
card-reference paths. This makes the ownership rule explicit and avoids
future missing-unref mistakes when adding early exits.
Cássio Gabriel [Thu, 4 Jun 2026 04:48:12 +0000 (01:48 -0300)]
ALSA: control: Use scoped cleanup for user control buffers
User-defined control TLV data and enum names are copied from user space
with vmemdup_user() before being installed in the user_element. Until
ownership is transferred, these temporary buffers have to be released on
every validation exit.
Use __free(kvfree) for the temporary buffers and no_free_ptr() when
ownership is transferred to the user_element. This removes the manual
kvfree() calls from the unchanged-TLV and enum-name validation paths,
makes the ownership hand-off explicit, and keeps the existing allocation
accounting and ABI unchanged.
The lockdep WARN was observed by running blktests test case nvme/005 for
tcp transport on v7.1-rc1 kernel with a patch. Refer to the Link tag for
the details of the WARN.
This is a false positive because lockdep confuses lock 4) (socket
establishment) with lock 5) (socket in use) for different socket
instances. The locks belong to different sockets, but lockdep treats
them as the same due to shared static lockdep keys.
Fix this by using dynamically allocated lockdep keys per socket instance
instead of static keys nvme_tcp_sk_key[] and nvme_tcp_slock_key[]. Add
nvme_tcp_sk_key and nvme_tcp_slock_key fields to struct nvme_tcp_queue
and pass them to sock_lock_init_class_and_name() for proper lockdep
tracking. Change the argument of nvme_tcp_reclassify_socket() from
'struct socket *' to 'struct nvme_tcp_queue *' to pass both the socket
and the keys. Add CONFIG_DEBUG_LOCK_ALLOC guards to nvme_tcp_alloc_queue()
and nvme_tcp_free_queue() to register and unregister the dynamic keys.
Additionally, move nvme_tcp_reclassify_socket() inside these guards since
it's only needed when lockdep is enabled.
Merge patch series "mm: improve write performance with RWF_DONTCACHE"
Jeff Layton <jlayton@kernel.org> says:
This patch series is intended to improve write performance with
RWF_DONTCACHE. This version fixes additional stat accounting issues
found during review: integer promotion on 32-bit, cgroup writeback
domain migration, folio split flag preservation, and a UAF that could
occur in filemap_dontcache_kick_writeback().
* patches from https://patch.msgid.link/20260511-dontcache-v7-0-2848ddce8090@kernel.org:
mm: kick writeback flusher for IOCB_DONTCACHE with targeted dirty tracking
mm: track DONTCACHE dirty pages per bdi_writeback
mm: preserve PG_dropbehind flag during folio split
ALSA: hda/realtek: Add quirk for ASUS VivoBook X509DAP
The internal microphone on ASUS VivoBook X509DAP (subsystem ID
0x1043:0x197e) is not detected without a quirk entry. Add
ALC256_FIXUP_ASUS_MIC_NO_PRESENCE to fix the issue.
Jeff Layton [Mon, 11 May 2026 11:58:29 +0000 (07:58 -0400)]
mm: kick writeback flusher for IOCB_DONTCACHE with targeted dirty tracking
The IOCB_DONTCACHE writeback path in generic_write_sync() calls
filemap_flush_range() on every write, submitting writeback inline in
the writer's context. Perf lock contention profiling shows the
performance problem is not lock contention but the writeback submission
work itself — walking the page tree and submitting I/O blocks the writer
for milliseconds, inflating p99.9 latency from 23ms (buffered) to 93ms
(dontcache).
Replace the inline filemap_flush_range() call with a flusher kick that
drains dirty pages in the background. This moves writeback submission
completely off the writer's hot path.
To avoid flushing unrelated buffered dirty data, add a dedicated
WB_start_dontcache bit and wb_check_start_dontcache() handler that uses
the per-wb WB_DONTCACHE_DIRTY counter to determine how many pages to
write back. The flusher writes back that many pages from the oldest dirty
inodes (not restricted to dontcache-specific inodes). This helps
preserve I/O batching while limiting the scope of expedited writeback.
Like WB_start_all, the WB_start_dontcache bit coalesces multiple
DONTCACHE writes into a single flusher wakeup without per-write
allocations. Use test_and_clear_bit to atomically consume the kick
request before reading the dirty counter and starting writeback, so that
concurrent DONTCACHE writes during writeback can re-set the bit and
schedule a follow-up flusher run.
Read the dirty counter with wb_stat_sum() (aggregating per-CPU batches)
rather than wb_stat() (which reads only the global counter) to ensure
small writes below the percpu batch threshold are visible to the flusher.
In filemap_dontcache_kick_writeback(), set the WB_start_dontcache bit
inside the unlocked_inode_to_wb_begin/end section for correct cgroup
writeback domain targeting, but defer the wb_wakeup() call until after
the section ends, since wb_wakeup() uses spin_unlock_irq() which would
unconditionally re-enable interrupts while the i_pages xa_lock may still
be held under irqsave during a cgroup writeback switch. Pin the wb with
wb_get() inside the RCU critical section before calling wb_wakeup()
outside it, since cgroup bdi_writeback structures are RCU-freed and the
wb pointer could become invalid after unlocked_inode_to_wb_end() drops
the RCU read lock.
Also add WB_REASON_DONTCACHE as a new writeback reason for tracing
visibility.
Dontcache now reaches 81% of buffered throughput (was 35%).
Competing writers (dontcache vs buffered, separate files):
Before After
buffered writer 868 433 MB/s
dontcache writer 415 433 MB/s
Aggregate 1,284 866 MB/s
Previously the buffered writer starved the dontcache writer 2:1.
With per-bdi_writeback tracking, both writers now receive equal
bandwidth. The aggregate matches the buffered-vs-buffered baseline
(863 MB/s), indicating fair sharing regardless of I/O mode.
The dontcache writer's p99.9 latency collapsed from 119 ms to
33 ms (-73%), eliminating the severe periodic stalls seen in the
baseline. Both writers now share identical latency profiles,
matching the buffered-vs-buffered pattern.
The per-bdi_writeback dirty tracking dramatically reduces peak dirty
pages in dontcache workloads, with the 32-file test dropping from
1.8 GB to 213 MB. Dontcache sequential write throughput triples and
multi-writer throughput reaches parity with buffered I/O, with tail
latencies collapsing by 1-2 orders of magnitude.
Assisted-by: Claude:claude-opus-4-6 Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://patch.msgid.link/20260511-dontcache-v7-3-2848ddce8090@kernel.org Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Jeff Layton [Mon, 11 May 2026 11:58:28 +0000 (07:58 -0400)]
mm: track DONTCACHE dirty pages per bdi_writeback
Add a per-wb WB_DONTCACHE_DIRTY counter that tracks the number of dirty
pages with the dropbehind flag set (i.e., pages dirtied via RWF_DONTCACHE
writes).
Increment the counter alongside WB_RECLAIMABLE in folio_account_dirtied()
when the folio has the dropbehind flag set, and decrement it in
folio_clear_dirty_for_io() and folio_account_cleaned(). Also decrement it
when a non-DONTCACHE lookup atomically clears the dropbehind flag on a
dirty folio in __filemap_get_folio_mpol(), using folio_test_clear_dropbehind()
to prevent concurrent lookups from double-decrementing the counter, and
guarding the decrement with mapping_can_writeback() to match the increment
path.
Transfer the counter alongside WB_RECLAIMABLE in inode_do_switch_wbs() so
that the stat is properly migrated when an inode switches cgroup writeback
domains.
The counter will be used by the writeback flusher to determine how many
pages to write back when expediting writeback for IOCB_DONTCACHE writes,
without flushing the entire BDI's dirty pages.
Suggested-by: Jan Kara <jack@suse.cz> Assisted-by: Claude:claude-opus-4-6 Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://patch.msgid.link/20260511-dontcache-v7-2-2848ddce8090@kernel.org Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Jeff Layton [Mon, 11 May 2026 11:58:27 +0000 (07:58 -0400)]
mm: preserve PG_dropbehind flag during folio split
__split_folio_to_order() copies page flags from the original folio to
newly created sub-folios using an explicit allowlist, but PG_dropbehind
is not included. When a large folio with PG_dropbehind set is split,
only the head sub-folio retains the flag; all tail sub-folios silently
lose it and will not be reclaimed eagerly after writeback completes.
Add PG_dropbehind to the flag copy mask so that the drop-behind hint
is preserved across folio splits.
Fixes: a323281cdfec ("mm: add PG_dropbehind folio flag") Assisted-by: Claude:claude-opus-4-6 Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://patch.msgid.link/20260511-dontcache-v7-1-2848ddce8090@kernel.org Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
wangdicheng [Wed, 3 Jun 2026 09:11:02 +0000 (17:11 +0800)]
ALSA: usb-audio: qcom: Use PAGE_ALIGN macro for buffer size calculation
Use the kernel's PAGE_ALIGN() macro instead of open-coding the page
alignment calculation. This improves code readability and follows
kernel coding style.
The manual calculation:
mult = len / PAGE_SIZE;
remainder = len % PAGE_SIZE;
len = mult * PAGE_SIZE;
len += remainder ? PAGE_SIZE : 0;
wangdicheng [Wed, 3 Jun 2026 09:11:01 +0000 (17:11 +0800)]
ALSA: usb-audio: qcom: Fix return value in qc_usb_audio_offload_fill_avail_pcms
The function qc_usb_audio_offload_fill_avail_pcms() always returns -1
regardless of how many PCM devices were successfully filled. This makes
it impossible for callers to know the actual number of available PCMs.
Return the actual count of filled PCM devices instead, which allows
callers to verify that all expected PCMs were properly enumerated.
wangdicheng [Wed, 3 Jun 2026 09:11:00 +0000 (17:11 +0800)]
ALSA: usb-audio: qcom: Use snprintf for mixer control name formatting
The current code uses sprintf() to format control names without bounds
checking, which could lead to buffer overflow if PCM index is large.
Replace sprintf with snprintf to ensure buffer safety.
The ctl_name buffer is 48 bytes, and the formatted string could exceed
this with large PCM index values. Using snprintf with sizeof(ctl_name)
prevents potential buffer overflow.
wangdicheng [Wed, 3 Jun 2026 09:10:59 +0000 (17:10 +0800)]
ALSA: usb-audio: qcom: Improve error logging in USB offload
Add error codes to error messages for better debugging.
This helps identify the root cause when USB audio offload fails.
Error messages now include the actual error code returned by
xhci_sideband operations, making it easier to diagnose failures
during USB audio offload setup.
Merge patch series "libfs: set SB_I_NOEXEC and SB_I_NODEV in init_pseudo()"
John Hubbard <jhubbard@nvidia.com> says:
This began as a one-line dma-buf fix for a path_noexec() warning added
by commit 1e7ab6f67824 ("anon_inode: rework assertions"). Christoph
pointed out that the fix belongs higher up: a pseudo filesystem has no
reason not to set SB_I_NOEXEC by default. This series does that.
* Patch 1 sets both flags in init_pseudo(), so every pseudo
filesystem gets them. This is the only patch that changes a flag,
and the only one with Fixes:/Cc: stable.
* Patch 2 drops the assignments that are now redundant in the callers
that set them by hand.
Most callers already set one or both flags. I audited every
init_pseudo() caller. Here is what patch 1 actually changes for each.
The only visible effect is on dma-buf, where SB_I_NOEXEC silences the
warning. SB_I_NODEV is never consulted on these SB_NOUSER mounts, and
none of the callers that gain SB_I_NOEXEC are executed from.
caller had patch 1 adds
--------------------------- -------- --------------
fs/anon_inodes.c both nothing new
mm/secretmem.c both nothing new
virt/kvm/guest_memfd.c both nothing new
fs/nsfs.c both nothing new
fs/pidfs.c both nothing new
fs/aio.c NOEXEC NODEV
drivers/dma-buf/dma-buf.c neither NOEXEC + NODEV
net/socket.c neither NOEXEC + NODEV
fs/pipe.c neither NOEXEC + NODEV
kernel/resource.c neither NOEXEC + NODEV
fs/erofs/super.c neither NOEXEC + NODEV
fs/btrfs/tests/... neither NOEXEC + NODEV
drivers/vfio/vfio_main.c neither NOEXEC + NODEV
drivers/gpu/drm/drm_drv.c neither NOEXEC + NODEV
drivers/dax/super.c neither NOEXEC + NODEV
block/bdev.c neither NOEXEC + NODEV
* patches from https://patch.msgid.link/20260604025315.245910-1-jhubbard@nvidia.com:
libfs: drop redundant SB_I_NOEXEC/SB_I_NODEV in init_pseudo() callers
libfs: set SB_I_NOEXEC and SB_I_NODEV by default in init_pseudo()
John Hubbard [Thu, 4 Jun 2026 02:53:14 +0000 (19:53 -0700)]
libfs: set SB_I_NOEXEC and SB_I_NODEV by default in init_pseudo()
Since commit 1e7ab6f67824 ("anon_inode: rework assertions"),
path_noexec() warns when an anonymous-inode file is mmap'd from a
superblock that has not set SB_I_NOEXEC. dma-buf backs its files this
way and never set the flag, so mmap of any exported buffer trips the
warning on a CONFIG_DEBUG_VFS=y kernel:
init_pseudo() sets up internal SB_NOUSER mounts that are never
path-reachable. Set both flags here so every pseudo filesystem gets
them by default instead of each caller setting them.
SB_I_NODEV is inert for unreachable mounts. SB_I_NOEXEC has one
visible effect: an executable mapping of a pseudo-fs fd, such as a
dma-buf, now fails with -EPERM, which is the invariant the assertion
enforces. No in-tree caller maps these executable.
Reproduce on CONFIG_DEBUG_VFS=y:
make -C tools/testing/selftests/dmabuf-heaps
sudo ./tools/testing/selftests/dmabuf-heaps/dmabuf-heap -t system
Fixes: 1e7ab6f67824 ("anon_inode: rework assertions") Suggested-by: Christoph Hellwig <hch@infradead.org> Cc: stable@vger.kernel.org Signed-off-by: John Hubbard <jhubbard@nvidia.com> Link: https://patch.msgid.link/20260604025315.245910-2-jhubbard@nvidia.com Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Joanne Koong [Thu, 4 Jun 2026 01:18:58 +0000 (18:18 -0700)]
iomap: avoid potential null folio->mapping deref during error reporting
When a buffered read fails, iomap_finish_folio_read() reports the error
with fserror_report_io(folio->mapping->host, ...). This is called after
ifs->read_bytes_pending has been decremented by the bytes attempted to
be read.
For a folio split across multiple read completions, the folio is only
guaranteed to stay locked while read_bytes_pending > 0. Once
iomap_finish_folio_read() decrements read_bytes_pending, another
in-flight read can complete and end the read on the folio, which unlocks
it. This allows truncate logic to run and detach the folio (set
folio->mapping to NULL). The error reporting path then can dereference a
NULL folio->mapping. As reported by Sam Sun, this is the race that can
occur:
CPU0: failed completion CPU1: final completion CPU2: truncate
----------------------- ---------------------- --------------
read_bytes_pending -= len
finished = false
/* preempted before
fserror_report_io() */
read_bytes_pending -= len
finished = true
folio_end_read()
truncate clears
folio->mapping
fserror_report_io(
folio->mapping->host, ...)
^ NULL deref
Fix this by reporting the error first before decrementing
ifs->read_bytes_pending.
Fixes: a9d573ee88af ("iomap: report file I/O errors to the VFS") Cc: stable@vger.kernel.org Reported-by: Sam Sun <samsun1006219@gmail.com> Closes: https://lore.kernel.org/linux-fsdevel/CAEkJfYPhWdd59RKmuNLJg-bkypHz7xiOwaWyNVu3A8CUqQCnvg@mail.gmail.com/ Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Link: https://patch.msgid.link/20260604011858.2297561-1-joannelkoong@gmail.com Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Jann Horn [Wed, 3 Jun 2026 19:31:57 +0000 (21:31 +0200)]
fhandle: fix UAF due to unlocked ->mnt_ns read in may_decode_fh()
may_decode_fh() accesses mount::mnt_ns without holding any locks; that
means the mount can concurrently be unmounted, and the mnt_namespace can
concurrently be freed after an RCU grace period.
This race can happens as follows, assuming that the mount point was
created by open_tree(..., OPEN_TREE_CLONE):
Fix it by taking rcu_read_lock() around the mount::mnt_ns access, like
in __prepend_path().
Additionally, document the semantics of mount::mnt_ns, and use WRITE_ONCE()
for writers that can race with lockless readers.
This bug is unreachable unless one of the following is set:
because it requires an RCU grace period to happen during a syscall without
an explicit preemption.
This doesn't seem to have interesting security impact; worst-case, it could
leak the result of an integer comparison to userspace (from the level
check in cap_capable()), cause an endless loop, or crash the kernel by
dereferencing an invalid address.
Miguel Ojeda [Tue, 2 Jun 2026 15:16:38 +0000 (17:16 +0200)]
kbuild: rust: rename flag to `-Zdebuginfo-for-profiling` for Rust >= 1.98
Starting with Rust 1.98.0 (expected 2026-08-20), the
`-Zdebug-info-for-profiling` flag has been renamed to
`-Zdebuginfo-for-profiling` (i.e. one less dash, to match `debuginfo`s
in other flags) [1].
Without this change, one gets in the latest nightlies:
Akash Sukhavasi [Wed, 20 May 2026 21:53:25 +0000 (16:53 -0500)]
arm64: dts: hisilicon: hi3660-hikey960: move role-switch endpoint into connector
The rt1711h Type-C controller on the HiKey960 has the USB role-switch
endpoint placed as a top-level 'port' node, outside the connector
subnode. This triggers two dtbs_check warnings against
richtek,rt1711h.yaml:
- 'port' does not match any of the regexes: '^pinctrl-[0-9]+$'
- connector:ports: 'port@0' is a required property
Move the role-switch endpoint into the connector's port@0, which is
where usb-connector.yaml expects it. Update the DWC3 remote-endpoint
phandle accordingly.
The TCPM core (tcpm.c) looks up the role switch starting from the
connector fwnode via fwnode_usb_role_switch_get(). With the endpoint
inside the connector's port@0, it is found through the primary lookup
path rather than the device-level fallback.
Cross-compiled for arm64. Verified with dt_binding_check and
dtbs_check. Not runtime-tested on hardware.
iommu/vt-d: Fix RB-tree corruption in probe error path
The info->node RB-tree member is zero-initialized via kzalloc. If
a device does not support ATS, the device_rbtree_insert() call is
skipped. If a subsequent probe step fails, the error path jumps to
device_rbtree_remove(), which misinterprets the zeroed node as
a tree root and corrupts the device RB-tree.
Fix this by explicitly initializing the RB-node as empty using
RB_CLEAR_NODE() during initialization and guarding the removal with
RB_EMPTY_NODE().
Guanghui Feng [Thu, 4 Jun 2026 06:03:09 +0000 (14:03 +0800)]
iommu/vt-d: Improve IOMMU fault information
In some environments, multiple PCIe segments exist, and PCIe device
information needs to be differentiated and identified based on the
segment. When an IOMMU fault event occurs, the IOMMU and device segment
information should be output in detail in dmar_fault_do_one.
iommu/vt-d: Clear Present bit before tearing down scalable-mode context entry
device_pasid_table_teardown() zeroes the 128-bit scalable-mode context
entry with context_clear_entry() while the Present bit is still set. This
creates a window where the hardware can fetch a torn entry, with some
fields already zeroed while Present is still set, leading to unpredictable
behavior or spurious faults. The context-cache invalidation is issued only
after the entry has been zeroed, and intel_pasid_free_table() then frees
the PASID directory pages, so the IOMMU can keep walking a stale Present=1
entry that points at freed memory.
While x86 provides strong write ordering, the compiler may reorder the two
64-bit writes to the entry, and the hardware fetch is not guaranteed to be
atomic with respect to multiple CPU writes.
Commit c1e4f1dccbe9d ("iommu/vt-d: Clear Present bit before tearing down
context entry") fixed this exact pattern in domain_context_clear_one() and
the copied-context path, but device_pasid_table_teardown() was not
converted.
Align it with the "Guidance to Software for Invalidations" in the VT-d
spec, Section 6.5.3.3, using the same ownership handshake as the sibling
fix: clear only the Present bit, flush it to the IOMMU, perform the
context-cache invalidation, and only then zero the rest of the entry.
Fixes: 81e921fd32161 ("iommu/vt-d: Fix NULL domain on device release") Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com> Assisted-by: Claude:claude-opus-4-7 Link: https://lore.kernel.org/r/20260528025557.3209367-1-michael.bommarito@gmail.com Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Lu Baolu [Thu, 4 Jun 2026 06:03:06 +0000 (14:03 +0800)]
iommu/vt-d: Avoid WARNING in sva unbind path
The Intel IOMMU driver allows SVA on devices even if they do not support
PCI/PRI. Commit 39c20c4e83b9 ("iommu/vt-d: Only handle IOPF for SVA when
PRI is supported") modified the SVA bind path to allow this configuration
by skipping IOPF enablement when PRI is missing. However, it failed to
update the unbind path.
This creates an imbalance: the unbind path attempts to disable IOPF for
a device that never had it enabled, triggering a WARNING in
intel_iommu_disable_iopf():
Fix this by bypassing IOPF operations for SVA domains on non-PRI hardware
in both the bind and unbind paths.
Fixes: 39c20c4e83b9 ("iommu/vt-d: Only handle IOPF for SVA when PRI is supported") Cc: stable@vger.kernel.org Reported-by: Nareshkumar Gollakoti <naresh.kumar.g@intel.com> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/20260519052917.3729796-1-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Qiang Ma [Tue, 26 May 2026 07:55:44 +0000 (15:55 +0800)]
RISC-V: KVM: Fix timer state restore
The KVM_REG_RISCV_TIMER_REG(state) one-reg write passes the value
written by userspace to kvm_riscv_vcpu_timer_next_event() when
re-enabling the timer.
That value is the timer state, KVM_RISCV_TIMER_STATE_ON, not the
timer compare value. During migration or state restore, userspace
restores the compare register separately, which stores the target
cycle in t->next_cycles. Re-arming the timer with the state value
schedules the next event at cycle 1 instead of the restored compare
value, causing the virtual timer to fire too early.
Use the restored compare value from t->next_cycles when turning the
timer back on.
Jiakai Xu [Tue, 26 May 2026 03:15:17 +0000 (03:15 +0000)]
RISC-V: KVM: Fix NULL pointer dereference in AIA IMSIC functions
Fuzzer reported a NULL pointer dereference in
kvm_riscv_vcpu_aia_imsic_put() when a VCPU's imsic_state was NULL while
kvm_riscv_aia_initialized() returned true.
The global initialized flag is set per-VM in aia_init(), but imsic_state
is allocated per-VCPU in kvm_riscv_vcpu_aia_imsic_init(). If a VCPU is
created after aia_init() has already run, its imsic_state remains NULL
while the global flag is true. When this VCPU is preempted, kvm_sched_out()
calls kvm_arch_vcpu_put() -> kvm_riscv_vcpu_aia_put() ->
kvm_riscv_vcpu_aia_imsic_put() which dereferences NULL.
Add NULL pointer guards to kvm_riscv_vcpu_aia_imsic_put(), consistent with
the NULL checks already present in all other functions in the same file.
Also add a NULL guard to kvm_riscv_vcpu_aia_imsic_release() and
kvm_riscv_vcpu_aia_imsic_has_interrupt() for the same reason.
Jiakai Xu [Mon, 25 May 2026 01:36:42 +0000 (01:36 +0000)]
RISC-V: KVM: Document a TOCTOU race in SBI system suspend handler
The SUSP handler checks that all other vCPUs are stopped before
entering system suspend, but a concurrent HSM HART_START can start
a vCPU after it has already passed the check.
This is a known TOCTOU race. We do not fix it because:
1. Triggering it requires a pathological guest.
2. Only guest state is at risk, not host integrity.
3. Userspace can double-check vCPU states before suspend.
Add a comment documenting the race and the rationale for not fixing it.
Signed-off-by: Jiakai Xu <jiakaiPeanut@gmail.com> Signed-off-by: Jiakai Xu <xujiakai2025@iscas.ac.cn> Assisted-by: YuanSheng:DeepSeek-V3.2 Reviewed-by: Andrew Jones <andrew.jones@oss.qualcomm.com> Link: https://lore.kernel.org/r/20260525013642.999187-1-xujiakai2025@iscas.ac.cn Signed-off-by: Anup Patel <anup@brainfault.org>
hwrng: virtio: clamp device-reported used.len at copy_data()
random_recv_done() stores the device-reported used.len directly into
vi->data_avail. copy_data() then indexes vi->data[] using
vi->data_idx (advanced by previous copy_data() calls) and issues a
memcpy() without re-validating either value against the posted
buffer size sizeof(vi->data) (SMP_CACHE_BYTES bytes, typically 32
or 64).
A malicious or buggy virtio-rng backend can set used.len beyond
sizeof(vi->data), steering the memcpy() past the end of the inline
array into adjacent kmalloc-1k slab bytes. hwrng_fillfn() mixes
those bytes into the guest RNG, and guest root can also observe
them directly via /dev/hwrng.
Concrete impact is inside the guest:
- Memory-safety / hardening: any virtio-rng backend that
over-reports used.len causes the driver to read past vi->data
into unrelated slab contents. hwrng_fillfn() is a kernel thread
that runs as soon as the device is probed; no guest userspace
interaction is required to first-trigger the OOB.
- Cross-boundary leak (confidential-compute threat model): a
malicious hypervisor cooperating with a malicious or compromised
guest root userspace can use /dev/hwrng as a leak channel for
guest-kernel heap data. The host sets a large used.len, guest
root reads /dev/hwrng, and the returned bytes contain guest
kernel slab contents that were adjacent to vi->data. In
practice, confidential-compute guests (SEV-SNP, TDX) usually
disable virtio-rng entirely, so this path is narrow, but the
fix is still worth carrying because the underlying
memory-safety bug contaminates the guest RNG on any host.
KASAN confirms the OOB on a 7.1-rc4 guest whose virtio-rng backend
has been patched to report used.len = 0x10000:
BUG: KASAN: slab-out-of-bounds in virtio_read+0x394/0x5d0
Read of size 64 at addr ffff88800ae0ba20 by task hwrng/52
Call Trace:
__asan_memcpy+0x23/0x60
virtio_read+0x394/0x5d0
hwrng_fillfn+0xb2/0x470
kthread+0x2cc/0x3a0
Allocated by task 1:
probe_common+0xa5/0x660
virtio_dev_probe+0x549/0xbc0
The buggy address belongs to the object at ffff88800ae0b800
which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 0 bytes to the right of
allocated 544-byte region [ffff88800ae0b800, ffff88800ae0ba20)
Same class of bug as commit c04db81cd028 ("net/9p: Fix buffer
overflow in USB transport layer"), which hardened
usb9pfs_rx_complete() against unchecked device-reported length in
the USB 9p transport.
With the clamp at point of use and array_index_nospec() in place,
the same harness boots cleanly: copy_data() returns zero for the
bogus report, the device-supplied bytes after data_idx are
discarded, and the driver issues a fresh request.
Fixes: f7f510ec1957 ("virtio: An entropy device, as suggested by hpa.") Cc: stable@vger.kernel.org Suggested-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com> Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-ID: <20260531142251.2792061-1-michael.bommarito@gmail.com>
The virtio_balloon device registers 5 queues (inflate, deflate, stats,
free_page, reporting) but only the first two are unconditional. The
stats, free_page and reporting queues are each conditional on their
respective feature bits. When any of these features are absent, the
corresponding vqs_info entry has name == NULL, creating holes in the
array.
The root cause is an indexing mismatch introduced when vq info storage
was changed to be passed as an argument. vp_find_vqs_msix() and
vp_find_vqs_intx() store the info pointer at vp_dev->vqs[i], where 'i'
is the caller's sparse array index. However, the virtqueue itself gets
vq->index assigned from queue_idx, a dense index that skips NULL
entries. When holes exist, 'i' and queue_idx diverge. Later,
vp_del_vqs() looks up info via vp_dev->vqs[vq->index] using the dense
index into the sparsely-populated array, and hits NULL.
Fix this by storing info at vp_dev->vqs[queue_idx] instead of
vp_dev->vqs[i], so the store index matches the lookup index
(vq->index). Apply the fix to both the MSIX and INTX paths.
Cc: Yichun Zhang <yichun@openresty.com> Cc: Jiri Pirko <jiri@nvidia.com> Cc: stable@vger.kernel.org # v6.11+ Tested-by: Yuka <yuka@umeyashiki.org> Fixes: 89a1c435aec2 ("virtio_pci: pass vq info as an argument to vp_setup_vq()") Signed-off-by: Ammar Faizi <ammarfaizi2@openresty.com>
Message-Id: <20260315141808.547081-1-ammarfaizi2@openresty.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
vhost: fix vhost_get_avail_idx for a non empty ring
vhost_get_avail_idx is supposed to report whether it has updated
vq->avail_idx. Instead, it returns whether all entries have been
consumed, which is usually the same. But not always - in
drivers/vhost/net.c and when mergeable buffers have been enabled, the
driver checks whether the combined entries are big enough to store an
incoming packet. If not, the driver re-enables notifications with
available entries still in the ring. The incorrect return value from
vhost_get_avail_idx propagates through vhost_enable_notify and causes
the host to livelock if the guest is not making progress, as vhost will
immediately disable notifications and retry using the available entries.
This goes back to commit d3bb267bbdcb ("vhost: cache avail index in
vhost_enable_notify()") which changed vhost_enable_notify() to compare
the freshly read avail index against vq->last_avail_idx instead of the
previously cached vq->avail_idx. Commit 7ad472397667 ("vhost: move
smp_rmb() into vhost_get_avail_idx()") then carried over the same
comparison when refactoring vhost_enable_notify() to call the unified
vhost_get_avail_idx().
The obvious fix is to make vhost_get_avail_idx do what the comment
says it does and report whether new entries have been added.
Reported-by: ShuangYu <shuangyu@yunyoo.cc> Fixes: d3bb267bbdcb ("vhost: cache avail index in vhost_enable_notify()") Cc: Stefan Hajnoczi <stefanha@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <559b04ae6ce52973c535dc47e461638b7f4c3d63.1772441455.git.mst@redhat.com>
Suraj Gupta [Mon, 1 Jun 2026 12:44:54 +0000 (18:14 +0530)]
net: axienet: Use dedicated ethtool_ops for the dmaengine path
The dmaengine path shares ethtool_ops with the legacy AXI DMA path,
including .get_coalesce/.set_coalesce that poke XAXIDMA_*_CR_OFFSET
directly. In dmaengine mode lp->dma_regs is not mapped by axienet, so
those ethtool calls touch unmapped/unrelated memory and report values
unrelated to the channel actually in use.
.get_ringparam/.set_ringparam only touch lp->rx_bd_num/lp->tx_bd_num,
fields used only by the legacy path for BD ring sizing. In dmaengine
mode the descriptor ring is owned by the dmaengine provider and these
fields are not consulted, so reporting them is misleading.
No dmaengine API exists today to query or program either coalescing
or ring size on behalf of the client, so neither can be exposed
meaningfully in dmaengine mode.
Add axienet_ethtool_dmaengine_ops without the coalesce and ringparam
hooks. Also move the ethtool_ops assignment from early probe into the
if/else alongside netdev_ops, so the legacy and dmaengine paths pick
their respective ops in one place. No functional change for the
legacy DMA path.
Andrew Jones [Wed, 27 May 2026 14:27:03 +0000 (09:27 -0500)]
kconfig: add kconfig-sym-check static checker
Add 'make kconfig-sym-check', a static checker that finds Kconfig
symbols referenced in expressions (select, depends on, default, etc.)
but never defined via config/menuconfig anywhere in the tree. New
dangling symbols are reported as errors (exit 1) unless they are
listed in an exclusion file, e.g.
KCONFIG_SYM_CHECK_EXCLUDES=sym-check-excludes make kconfig-sym-check
The exclusion file lists one symbol per line; blank lines and lines
starting with '#' are ignored.
The checker also warns about uppercase N/Y/M used as tristate literal
values following the same logic as checkpatch.
This new static checker is the script used for [1] with a few
improvements to avoid some false positives.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216748 Assisted-by: Claude:claude-sonnet-4-6 Signed-off-by: Andrew Jones <andrew.jones@linux.dev> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Tested-by: Randy Dunlap <rdunlap@infradead.org> Tested-by: Julian Braha <julianbraha@gmail.com> Tested-by: Nicolas Schier <nsc@kernel.org> Acked-by: Nicolas Schier <nsc@kernel.org> Link: https://patch.msgid.link/20260527142703.107110-1-andrew.jones@linux.dev Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Jakub Raczynski [Mon, 1 Jun 2026 16:37:27 +0000 (18:37 +0200)]
net/sun: Fix multiple typos in comments
There are some typos in comments and while they are harmless and not visible,
there is no reason not to fix them. Fix the ones that are not register related,
which might have intentional naming convention.
Jakub Kicinski [Tue, 2 Jun 2026 00:37:59 +0000 (17:37 -0700)]
eth: bnxt: disable rx-copybreak by default
rx-copybreak requires an extra slab allocation. Since bnxt uses
page pool frags and HDS by default, the rx-copybreak doesn't
buy us anything. The extra pressure on slab causes overload
on pre-sheaves kernels on modern AMD platforms.
In synthetic testing on net-next this patch shows little difference
but I think copybreak is "obvious waste" at this point.
Default rx-copybreak threshold to 0 / disabled.
The "copybreak" defines are really the size bounds for the Rx header
buffer. Rename them.
====================
Fix use-after-free in metadata dst teardown in airoha_eth and mtk_eth_soc drivers
airoha_metadata_dst_free() and mtk_free_dev() call metadata_dst_free()
which frees the metadata_dst with kfree() immediately, bypassing the RCU
grace period.
Replace metadata_dst_free() with dst_release() which properly goes
through the refcount path and runs call_rcu_hurry() if refcount goes to
zero.
====================
net: ethernet: mtk_eth_soc: Fix use-after-free in metadata dst teardown
mtk_free_dev() calls metadata_dst_free() which frees the metadata_dst
with kfree() immediately, bypassing the RCU grace period.
In the RX path, skb_dst_set_noref() sets a non-refcounted pointer from
the skb to the metadata_dst. This function requires RCU read-side
protection and the dst must remain valid until all RCU readers complete.
Since metadata_dst_free() calls kfree() directly, a use-after-free can
occur if any skb still holds a noref pointer to the dst when the driver
tears it down.
Replace metadata_dst_free() with dst_release() which properly goes
through the refcount path: when the refcount drops to zero, it schedules
the actual free via call_rcu_hurry(), ensuring all RCU readers have
completed before the memory is freed.
net: airoha: Fix use-after-free in metadata dst teardown
airoha_metadata_dst_free() runs metadata_dst_free() which frees the
metadata_dst with kfree() immediately, bypassing the RCU grace period.
In the RX path, skb_dst_set_noref() sets a non-refcounted pointer from
the skb to the metadata_dst. This function requires RCU read-side
protection and the dst must remain valid until all RCU readers complete.
Since metadata_dst_free() calls kfree() directly, an use-after-free can
occur if any skb still holds a noref pointer to the dst when the driver
tears it down.
Replace metadata_dst_free() with dst_release() which properly goes
through the refcount path: when the refcount drops to zero, it schedules
the actual free via call_rcu_hurry(), ensuring all RCU readers have
completed before the memory is freed.
Justin Iurman [Tue, 2 Jun 2026 21:30:33 +0000 (23:30 +0200)]
ipv6: exthdrs: recompute network header pointer once
In ip6_parse_tlv(), recompute the network header pointer once regardless
of the option processed (Hbh or Dest), as missing recomputation for
specific options has caused issues in the past.
Rosen Penev [Mon, 1 Jun 2026 04:02:00 +0000 (21:02 -0700)]
net: ibm: emac: fix unchecked platform_get_irq return value
platform_get_irq() returns a negative errno on failure.
Commit a598f66d9169 replaced irq_of_parse_and_map() (which returns 0
on failure) with platform_get_irq() but dropped the error check.
Without it, a negative IRQ number is passed to devm_request_irq(),
which fails with -EINVAL instead of propagating the real error
from platform_get_irq().
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