linux-stable.git/kernel/time, branch v6.6.141

hrtimer: Reduce trace noise in hrtimer_start()

2026-05-23T11:03:06+00:00

[ Upstream commit f2e388a019e4cf83a15883a3d1f1384298e9a6aa ]

hrtimer_start() when invoked with an already armed timer traces like:

 -..   [032] d.h2. 5.002263: hrtimer_cancel: hrtimer= ....
 -..   [032] d.h1. 5.002263: hrtimer_start: hrtimer= ....

Which is incorrect as the timer doesn't get canceled. Just the expiry time
changes. The internal dequeue operation which is required for that is not
really interesting for trace analysis. But it makes it tedious to keep real
cancellations and the above case apart.

Remove the cancel tracing in hrtimer_start() and add a 'was_armed'
indicator to the hrtimer start tracepoint, which clearly indicates what the
state of the hrtimer is when hrtimer_start() is invoked:

-..   [032] d.h1. 6.200103: hrtimer_start: hrtimer= .... was_armed=0
 -..   [032] d.h1. 6.200558: hrtimer_start: hrtimer= .... was_armed=1

Fixes: c6a2a1770245 ("hrtimer: Add tracepoint for hrtimers")
Signed-off-by: Thomas Gleixner 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://patch.msgid.link/20260224163430.208491877@kernel.org
Signed-off-by: Sasha Levin

hrtimer: Avoid pointless reprogramming in __hrtimer_start_range_ns()

2026-05-23T11:03:05+00:00

[ Upstream commit d19ff16c11db38f3ee179d72751fb9b340174330 ]

Much like hrtimer_reprogram(), skip programming if the cpu_base is running
the hrtimer interrupt.

Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Peter Zijlstra (Intel) 
Reviewed-by: Juri Lelli 
Reviewed-by: Thomas Gleixner 
Link: https://patch.msgid.link/20260224163429.069535561@kernel.org
Stable-dep-of: f2e388a019e4 ("hrtimer: Reduce trace noise in hrtimer_start()")
Signed-off-by: Sasha Levin

hrtimers: Update the return type of enqueue_hrtimer()

2026-05-23T11:03:05+00:00

[ Upstream commit da7100d3bf7d6f5c49ef493ea963766898e9b069 ]

The return type should be 'bool' instead of 'int' according to the calling
context in the kernel, and its internal implementation, i.e. :

	return timerqueue_add();

which is a bool-return function.

[ tglx: Adjust function arguments ]

Signed-off-by: Richard Clark 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/all/Z2ppT7me13dtxm1a@MBC02GN1V4Q05P
Stable-dep-of: f2e388a019e4 ("hrtimer: Reduce trace noise in hrtimer_start()")
Signed-off-by: Sasha Levin

alarmtimer: Fix argument order in alarm_timer_forward()

2026-04-02T11:07:26+00:00

commit 5d16467ae56343b9205caedf85e3a131e0914ad8 upstream.

alarm_timer_forward() passes arguments to alarm_forward() in the wrong
order:

  alarm_forward(alarm, timr->it_interval, now);

However, alarm_forward() is defined as:

  u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval);

and uses the second argument as the current time:

  delta = ktime_sub(now, alarm->node.expires);

Passing the interval as "now" results in incorrect delta computation,
which can lead to missed expirations or incorrect overrun accounting.

This issue has been present since the introduction of
alarm_timer_forward().

Fix this by swapping the arguments.

Fixes: e7561f1633ac ("alarmtimer: Implement forward callback")
Signed-off-by: Zhan Xusheng 
Signed-off-by: Thomas Gleixner 
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260323061130.29991-1-zhanxusheng@xiaomi.com
Signed-off-by: Greg Kroah-Hartman

time/jiffies: Mark jiffies_64_to_clock_t() notrace

2026-03-25T10:05:51+00:00

[ Upstream commit 755a648e78f12574482d4698d877375793867fa1 ]

The trace_clock_jiffies() function that handles the "uptime" clock for
tracing calls jiffies_64_to_clock_t(). This causes the function tracer to
constantly recurse when the tracing clock is set to "uptime". Mark it
notrace to prevent unnecessary recursion when using the "uptime" clock.

Fixes: 58d4e21e50ff3 ("tracing: Fix wraparound problems in "uptime" trace clock")
Signed-off-by: Steven Rostedt (Google) 
Signed-off-by: Thomas Gleixner 
Link: https://patch.msgid.link/20260306212403.72270bb2@robin
Signed-off-by: Sasha Levin

hrtimer: Fix trace oddity

2026-03-04T12:19:32+00:00

[ Upstream commit 5d6446f409da00e5a389125ddb5ce09f5bc404c9 ]

It turns out that __run_hrtimer() will trace like:

          -0     [032] d.h2. 20705.474563: hrtimer_cancel:       hrtimer=0xff2db8f77f8226e8
          -0     [032] d.h1. 20705.474563: hrtimer_expire_entry: hrtimer=0xff2db8f77f8226e8 now=20699452001850 function=tick_nohz_handler/0x0

Which is a bit nonsensical, the timer doesn't get canceled on
expiration. The cause is the use of the incorrect debug helper.

Fixes: c6a2a1770245 ("hrtimer: Add tracepoint for hrtimers")
Reported-by: Peter Zijlstra (Intel) 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://patch.msgid.link/20260121143208.219595606@infradead.org
Signed-off-by: Sasha Levin

ptp: Add PHC file mode checks. Allow RO adjtime() without FMODE_WRITE.

2026-01-30T09:27:30+00:00

[ Upstream commit b4e53b15c04e3852949003752f48f7a14ae39e86 ]

Many devices implement highly accurate clocks, which the kernel manages
as PTP Hardware Clocks (PHCs). Userspace applications rely on these
clocks to timestamp events, trace workload execution, correlate
timescales across devices, and keep various clocks in sync.

The kernel’s current implementation of PTP clocks does not enforce file
permissions checks for most device operations except for POSIX clock
operations, where file mode is verified in the POSIX layer before
forwarding the call to the PTP subsystem. Consequently, it is common
practice to not give unprivileged userspace applications any access to
PTP clocks whatsoever by giving the PTP chardevs 600 permissions. An
example of users running into this limitation is documented in [1].
Additionally, POSIX layer requires WRITE permission even for readonly
adjtime() calls which are used in PTP layer to return current frequency
offset applied to the PHC.

Add permission checks for functions that modify the state of a PTP
device. Continue enforcing permission checks for POSIX clock operations
(settime, adjtime) in the POSIX layer. Only require WRITE access for
dynamic clocks adjtime() if any flags are set in the modes field.

[1] https://lists.nwtime.org/sympa/arc/linuxptp-users/2024-01/msg00036.html

Changes in v4:
- Require FMODE_WRITE in ajtime() only for calls modifying the clock in
  any way.

Acked-by: Richard Cochran 
Reviewed-by: Vadim Fedorenko 
Signed-off-by: Wojtek Wasko 
Reviewed-by: Thomas Gleixner 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

posix-clock: Store file pointer in struct posix_clock_context

2026-01-30T09:27:30+00:00

[ Upstream commit e859d375d1694488015e6804bfeea527a0b25b9f ]

File descriptor based pc_clock_*() operations of dynamic posix clocks
have access to the file pointer and implement permission checks in the
generic code before invoking the relevant dynamic clock callback.

Character device operations (open, read, poll, ioctl) do not implement a
generic permission control and the dynamic clock callbacks have no
access to the file pointer to implement them.

Extend struct posix_clock_context with a struct file pointer and
initialize it in posix_clock_open(), so that all dynamic clock callbacks
can access it.

Acked-by: Richard Cochran 
Reviewed-by: Vadim Fedorenko 
Reviewed-by: Thomas Gleixner 
Signed-off-by: Wojtek Wasko 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

Fix memory leak in posix_clock_open()

2026-01-30T09:27:30+00:00

[ Upstream commit 5b4cdd9c5676559b8a7c944ac5269b914b8c0bb8 ]

If the clk ops.open() function returns an error, we don't release the
pccontext we allocated for this clock.

Re-organize the code slightly to make it all more obvious.

Reported-by: Rohit Keshri 
Acked-by: Oleg Nesterov 
Fixes: 60c6946675fc ("posix-clock: introduce posix_clock_context concept")
Cc: Jakub Kicinski 
Cc: David S. Miller 
Cc: Thomas Gleixner 
Signed-off-by: Linus Torvalds 
Stable-dep-of: e859d375d169 ("posix-clock: Store file pointer in struct posix_clock_context")
Signed-off-by: Sasha Levin

posix-clock: introduce posix_clock_context concept

2026-01-30T09:27:30+00:00

[ Upstream commit 60c6946675fc06dd2fd2b7a4b6fd1c1f046f1056 ]

Add the necessary structure to support custom private-data per
posix-clock user.

The previous implementation of posix-clock assumed all file open
instances need access to the same clock structure on private_data.

The need for individual data structures per file open instance has been
identified when developing support for multiple timestamp event queue
users for ptp_clock.

Signed-off-by: Xabier Marquiegui 
Suggested-by: Richard Cochran 
Suggested-by: Vinicius Costa Gomes 
Signed-off-by: David S. Miller 
Stable-dep-of: e859d375d169 ("posix-clock: Store file pointer in struct posix_clock_context")
Signed-off-by: Sasha Levin