Merge tag 'v6.6.29' into dev-6.6

This is the 6.6.29 stable release

selftests: timers: Fix posix_timers ksft_print_msg() warning

[ Upstream commit e4a6bceac98eba3c00e874892736b34ea5fdaca3 ]

After commit 6d029c25b71f ("selftests/timers/posix_timers: Reimplement
chec

selftests: timers: Fix posix_timers ksft_print_msg() warning

[ Upstream commit e4a6bceac98eba3c00e874892736b34ea5fdaca3 ]

After commit 6d029c25b71f ("selftests/timers/posix_timers: Reimplement
check_timer_distribution()") the following warning occurs when building
with an older gcc:

posix_timers.c:250:2: warning: format not a string literal and no format arguments [-Wformat-security]
250 | ksft_print_msg(errmsg);
| ^~~~~~~~~~~~~~

Fix this up by changing it to ksft_print_msg("%s", errmsg)

Fixes: 6d029c25b71f ("selftests/timers/posix_timers: Reimplement check_timer_distribution()")
Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Justin Stitt <justinstitt@google.com>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240410232637.4135564-1-jstultz@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

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selftests/timers/posix_timers: Reimplement check_timer_distribution()

[ Upstream commit 6d029c25b71f2de2838a6f093ce0fa0e69336154 ]

check_timer_distribution() runs ten threads in a busy loop and tri

selftests/timers/posix_timers: Reimplement check_timer_distribution()

[ Upstream commit 6d029c25b71f2de2838a6f093ce0fa0e69336154 ]

check_timer_distribution() runs ten threads in a busy loop and tries to
test that the kernel distributes a process posix CPU timer signal to every
thread over time.

There is not guarantee that this is true even after commit bcb7ee79029d
("posix-timers: Prefer delivery of signals to the current thread") because
that commit only avoids waking up the sleeping process leader thread, but
that has nothing to do with the actual signal delivery.

As the signal is process wide the first thread which observes sigpending
and wins the race to lock sighand will deliver the signal. Testing shows
that this hangs on a regular base because some threads never win the race.

The comment "This primarily tests that the kernel does not favour any one."
is wrong. The kernel does favour a thread which hits the timer interrupt
when CLOCK_PROCESS_CPUTIME_ID expires.

Rewrite the test so it only checks that the group leader sleeping in join()
never receives SIGALRM and the thread which burns CPU cycles receives all
signals.

In older kernels which do not have commit bcb7ee79029d ("posix-timers:
Prefer delivery of signals to the current thread") the test-case fails
immediately, the very 1st tick wakes the leader up. Otherwise it quickly
succeeds after 100 ticks.

CI testing wants to use newer selftest versions on stable kernels. In this
case the test is guaranteed to fail.

So check in the failure case whether the kernel version is less than v6.3
and skip the test result in that case.

[ tglx: Massaged change log, renamed the version check helper ]

Fixes: e797203fb3ba ("selftests/timers/posix_timers: Test delivery of signals across threads")
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240409133802.GD29396@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

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selftests: timers: Convert posix_timers test to generate KTAP output

[ Upstream commit 071af0c9e582bc47e379e39490a2bc1adfe4ec68 ]

Currently the posix_timers test does not produce KTAP output but ra

selftests: timers: Convert posix_timers test to generate KTAP output

[ Upstream commit 071af0c9e582bc47e379e39490a2bc1adfe4ec68 ]

Currently the posix_timers test does not produce KTAP output but rather a
custom format. This means that we only get a pass/fail for the suite, not
for each individual test that the suite does. Convert to using the standard
kselftest output functions which result in KTAP output being generated.

As part of this fix the printing of diagnostics in the unlikely event that
the pthread APIs fail, these were using perror() but the API functions
directly return an error code instead of setting errno.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Stable-dep-of: 6d029c25b71f ("selftests/timers/posix_timers: Reimplement check_timer_distribution()")
Signed-off-by: Sasha Levin <sashal@kernel.org>

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Merge tag 'v6.6.28' into dev-6.6

This is the 6.6.28 stable release

selftests: timers: Fix abs() warning in posix_timers test

commit ed366de8ec89d4f960d66c85fc37d9de22f7bf6d upstream.

Building with clang results in the following warning:

posix_timers.c:69:6: war

selftests: timers: Fix abs() warning in posix_timers test

commit ed366de8ec89d4f960d66c85fc37d9de22f7bf6d upstream.

Building with clang results in the following warning:

posix_timers.c:69:6: warning: absolute value function 'abs' given an
argument of type 'long long' but has parameter of type 'int' which may
cause truncation of value [-Wabsolute-value]
if (abs(diff - DELAY * USECS_PER_SEC) > USECS_PER_SEC / 2) {
^
So switch to using llabs() instead.

Fixes: 0bc4b0cf1570 ("selftests: add basic posix timers selftests")
Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240410232637.4135564-3-jstultz@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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Merge branch 'next' into for-linus

Prepare input updates for 6.6 merge window.

Merge tag 'v6.4' into next

Sync up with mainline to bring in updates to shared infrastructure.

Merge drm/drm-next into drm-misc-next-fixes

Backmerging to sync drm-misc-next-fixes with drm-misc-next.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Merge branch 'drm-next' of git://anongit.freedesktop.org/drm/drm into msm-next-lumag-base

Merge the drm-next tree to pick up the DRM DSC helpers (merged via
drm-intel-next tree). MSM DSC v1.2 patche

Merge branch 'drm-next' of git://anongit.freedesktop.org/drm/drm into msm-next-lumag-base

Merge the drm-next tree to pick up the DRM DSC helpers (merged via
drm-intel-next tree). MSM DSC v1.2 patches depend on these helpers.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

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Merge tag 'v6.4-rc4' into wpan-next/staging

Linux 6.4-rc4

Merge drm/drm-next into drm-intel-gt-next

For conflict avoidance we need the following commit:

c9a9f18d3ad8 drm/i915/huc: use const struct bus_type pointers

Signed-off-by: Tvrtko Ursulin <tvrtko

Merge drm/drm-next into drm-intel-gt-next

For conflict avoidance we need the following commit:

c9a9f18d3ad8 drm/i915/huc: use const struct bus_type pointers

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

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Merge drm/drm-next into drm-intel-next

Backmerge to get some hwmon dependencies.

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

Merge drm/drm-fixes into drm-misc-fixes

Let's bring 6.4-rc1 in drm-misc-fixes to start the new fix cycle.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>

Merge drm/drm-next into drm-misc-next

Start the 6.5 release cycle.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>

Merge tag 'timers-core-2023-04-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timers and timekeeping updates from Thomas Gleixner:

- Improve the VDSO build time checks to cover

Merge tag 'timers-core-2023-04-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timers and timekeeping updates from Thomas Gleixner:

- Improve the VDSO build time checks to cover all dynamic relocations

VDSO does not allow dynamic relocations, but the build time check is
incomplete and fragile.

It's based on architectures specifying the relocation types to search
for and does not handle R_*_NONE relocation entries correctly.
R_*_NONE relocations are injected by some GNU ld variants if they
fail to determine the exact .rel[a]/dyn_size to cover trailing zeros.
R_*_NONE relocations must be ignored by dynamic loaders, so they
should be ignored in the build time check too.

Remove the architecture specific relocation types to check for and
validate strictly that no other relocations than R_*_NONE end up in
the VSDO .so file.

- Prefer signal delivery to the current thread for
CLOCK_PROCESS_CPUTIME_ID based posix-timers

Such timers prefer to deliver the signal to the main thread of a
process even if the context in which the timer expires is the current
task. This has the downside that it might wake up an idle thread.

As there is no requirement or guarantee that the signal has to be
delivered to the main thread, avoid this by preferring the current
task if it is part of the thread group which shares sighand.

This not only avoids waking idle threads, it also distributes the
signal delivery in case of multiple timers firing in the context of
different threads close to each other better.

- Align the tick period properly (again)

For a long time the tick was starting at CLOCK_MONOTONIC zero, which
allowed users space applications to either align with the tick or to
place a periodic computation so that it does not interfere with the
tick. The alignement of the tick period was more by chance than by
intention as the tick is set up before a high resolution clocksource
is installed, i.e. timekeeping is still tick based and the tick
period advances from there.

The early enablement of sched_clock() broke this alignement as the
time accumulated by sched_clock() is taken into account when
timekeeping is initialized. So the base value now(CLOCK_MONOTONIC) is
not longer a multiple of tick periods, which breaks applications
which relied on that behaviour.

Cure this by aligning the tick starting point to the next multiple of
tick periods, i.e 1000ms/CONFIG_HZ.

- A set of NOHZ fixes and enhancements:

* Cure the concurrent writer race for idle and IO sleeptime
statistics

The statitic values which are exposed via /proc/stat are updated
from the CPU local idle exit and remotely by cpufreq, but that
happens without any form of serialization. As a consequence
sleeptimes can be accounted twice or worse.

Prevent this by restricting the accumulation writeback to the CPU
local idle exit and let the remote access compute the accumulated
value.

* Protect idle/iowait sleep time with a sequence count

Reading idle/iowait sleep time, e.g. from /proc/stat, can race
with idle exit updates. As a consequence the readout may result
in random and potentially going backwards values.

Protect this by a sequence count, which fixes the idle time
statistics issue, but cannot fix the iowait time problem because
iowait time accounting races with remote wake ups decrementing
the remote runqueues nr_iowait counter. The latter is impossible
to fix, so the only way to deal with that is to document it
properly and to remove the assertion in the selftest which
triggers occasionally due to that.

* Restructure struct tick_sched for better cache layout

* Some small cleanups and a better cache layout for struct
tick_sched

- Implement the missing timer_wait_running() callback for POSIX CPU
timers

For unknown reason the introduction of the timer_wait_running()
callback missed to fixup posix CPU timers, which went unnoticed for
almost four years.

While initially only targeted to prevent livelocks between a timer
deletion and the timer expiry function on PREEMPT_RT enabled kernels,
it turned out that fixing this for mainline is not as trivial as just
implementing a stub similar to the hrtimer/timer callbacks.

The reason is that for CONFIG_POSIX_CPU_TIMERS_TASK_WORK enabled
systems there is a livelock issue independent of RT.

CONFIG_POSIX_CPU_TIMERS_TASK_WORK=y moves the expiry of POSIX CPU
timers out from hard interrupt context to task work, which is handled
before returning to user space or to a VM. The expiry mechanism moves
the expired timers to a stack local list head with sighand lock held.
Once sighand is dropped the task can be preempted and a task which
wants to delete a timer will spin-wait until the expiry task is
scheduled back in. In the worst case this will end up in a livelock
when the preempting task and the expiry task are pinned on the same
CPU.

The timer wheel has a timer_wait_running() mechanism for RT, which
uses a per CPU timer-base expiry lock which is held by the expiry
code and the task waiting for the timer function to complete blocks
on that lock.

This does not work in the same way for posix CPU timers as there is
no timer base and expiry for process wide timers can run on any task
belonging to that process, but the concept of waiting on an expiry
lock can be used too in a slightly different way.

Add a per task mutex to struct posix_cputimers_work, let the expiry
task hold it accross the expiry function and let the deleting task
which waits for the expiry to complete block on the mutex.

In the non-contended case this results in an extra
mutex_lock()/unlock() pair on both sides.

This avoids spin-waiting on a task which is scheduled out, prevents
the livelock and cures the problem for RT and !RT systems

* tag 'timers-core-2023-04-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
posix-cpu-timers: Implement the missing timer_wait_running callback
selftests/proc: Assert clock_gettime(CLOCK_BOOTTIME) VS /proc/uptime monotonicity
selftests/proc: Remove idle time monotonicity assertions
MAINTAINERS: Remove stale email address
timers/nohz: Remove middle-function __tick_nohz_idle_stop_tick()
timers/nohz: Add a comment about broken iowait counter update race
timers/nohz: Protect idle/iowait sleep time under seqcount
timers/nohz: Only ever update sleeptime from idle exit
timers/nohz: Restructure and reshuffle struct tick_sched
tick/common: Align tick period with the HZ tick.
selftests/timers/posix_timers: Test delivery of signals across threads
posix-timers: Prefer delivery of signals to the current thread
vdso: Improve cmd_vdso_check to check all dynamic relocations

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selftests/timers/posix_timers: Test delivery of signals across threads

Test that POSIX timers using CLOCK_PROCESS_CPUTIME_ID eventually deliver
a signal to all running threads. This effectively tes

selftests/timers/posix_timers: Test delivery of signals across threads

Test that POSIX timers using CLOCK_PROCESS_CPUTIME_ID eventually deliver
a signal to all running threads. This effectively tests that the kernel
doesn't prefer any one thread (or subset of threads) for signal delivery.

Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230316123028.2890338-2-elver@google.com

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Merge remote-tracking branch 'remotes/powerpc/topic/ppc-kvm' into kvm-ppc-next

This merges in fixes for the XIVE interrupt controller which touch both
generic powerpc and PPC KVM code. To avoid mer

Merge remote-tracking branch 'remotes/powerpc/topic/ppc-kvm' into kvm-ppc-next

This merges in fixes for the XIVE interrupt controller which touch both
generic powerpc and PPC KVM code. To avoid merge conflicts, these
commits will go upstream via the powerpc tree as well as the KVM tree.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

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Merge branch 'ti-sysc-fixes' into fixes

Merge branch 'next' into for-linus

Prepare second round of input updates for 5.3 merge window.

Merge tag 'v5.2' into next

Sync up with mainline to resolve conflicts in iforce driver.

Merge tag 'kvm-arm-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm updates for 5.3

- Add support for chained PMU counters in guests
- Improve SError handli

Merge tag 'kvm-arm-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm updates for 5.3

- Add support for chained PMU counters in guests
- Improve SError handling
- Handle Neoverse N1 erratum #1349291
- Allow side-channel mitigation status to be migrated
- Standardise most AArch64 system register accesses to msr_s/mrs_s
- Fix host MPIDR corruption on 32bit

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Merge drm/drm-next into drm-intel-next-queued

Catch-up with 5.2. Specially to remove a drm-tip merge
fixup around intel_workarounds.

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

Merge branches 'for-5.2/fixes', 'for-5.3/doc', 'for-5.3/ish', 'for-5.3/logitech' and 'for-5.3/wacom' into for-linus

Merge tag 'asoc-v5.3' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus

ASoC: Updates for v5.3

This is a very big update, mainly thanks to Morimoto-san's refactoring
w

Merge tag 'asoc-v5.3' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus

ASoC: Updates for v5.3

This is a very big update, mainly thanks to Morimoto-san's refactoring
work and some fairly large new drivers.

- Lots more work on moving towards a component based framework from
Morimoto-san.
- Support for force disconnecting muxes from Jerome Brunet.
- New drivers for Cirrus Logic CS47L35, CS47L85 and CS47L90, Conexant
CX2072X, Realtek RT1011 and RT1308.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

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