linux-stable.git/kernel/reboot.c, branch v6.14.3

Flush console log from kernel_power_off()

2025-04-20T08:22:24+00:00

[ Upstream commit 6ea9a1781c70a8be1fcdc49134fc1bf4baba8bca ]

Kernels built with CONFIG_PREEMPT_RT=y can lose significant console output
and shutdown time, which hides shutdown-time RCU issues from rcutorture.
Therefore, make pr_flush() public and invoke it after then last print
in kernel_power_off().

[ paulmck: Apply John Ogness feedback. ]
[ paulmck: Appy Sebastian Andrzej Siewior feedback. ]
[ paulmck: Apply kernel test robot feedback. ]

Signed-off-by: Paul E. McKenney 
Reviewed-by: John Ogness 
Reviewed-by: Petr Mladek 
Cc: Steven Rostedt 
Cc: Sergey Senozhatsky 
Link: https://lore.kernel.org/r/5f743488-dc2a-4f19-bdda-cf50b9314832@paulmck-laptop
Signed-off-by: Boqun Feng 
Signed-off-by: Sasha Levin

reboot: reboot, not shutdown, on hw_protection_reboot timeout

2025-04-10T12:44:32+00:00

[ Upstream commit bbf0ec4f57e0a34983ca25f00ec90f4765572d78 ]

hw_protection_shutdown() will kick off an orderly shutdown and if that
takes longer than a configurable amount of time, an emergency shutdown
will occur.

Recently, hw_protection_reboot() was added for those systems that don't
implement a proper shutdown and are better served by rebooting and having
the boot firmware worry about doing something about the critical
condition.

On timeout of the orderly reboot of hw_protection_reboot(), the system
would go into shutdown, instead of reboot.  This is not a good idea, as
going into shutdown was explicitly not asked for.

Fix this by always doing an emergency reboot if hw_protection_reboot() is
called and the orderly reboot takes too long.

Link: https://lkml.kernel.org/r/20250217-hw_protection-reboot-v3-2-e1c09b090c0c@pengutronix.de
Fixes: 79fa723ba84c ("reboot: Introduce thermal_zone_device_critical_reboot()")
Signed-off-by: Ahmad Fatoum 
Reviewed-by: Tzung-Bi Shih 
Reviewed-by: Matti Vaittinen 
Cc: Benson Leung 
Cc: Daniel Lezcano 
Cc: Fabio Estevam 
Cc: Guenter Roeck 
Cc: Jonathan Corbet 
Cc: Liam Girdwood 
Cc: Lukasz Luba 
Cc: Mark Brown 
Cc: Matteo Croce 
Cc: "Rafael J. Wysocki" 
Cc: Rob Herring (Arm) 
Cc: Rui Zhang 
Cc: Sascha Hauer 
Cc: "Serge E. Hallyn" 
Signed-off-by: Andrew Morton 
Signed-off-by: Sasha Levin

reboot: replace __hw_protection_shutdown bool action parameter with an enum

2025-04-10T12:44:32+00:00

[ Upstream commit 318f05a057157c400a92f17c5f2fa3dd96f57c7e ]

Patch series "reboot: support runtime configuration of emergency
hw_protection action", v3.

We currently leave the decision of whether to shutdown or reboot to
protect hardware in an emergency situation to the individual drivers.

This works out in some cases, where the driver detecting the critical
failure has inside knowledge: It binds to the system management controller
for example or is guided by hardware description that defines what to do.

This is inadequate in the general case though as a driver reporting e.g.
an imminent power failure can't know whether a shutdown or a reboot would
be more appropriate for a given hardware platform.

To address this, this series adds a hw_protection kernel parameter and
sysfs toggle that can be used to change the action from the shutdown
default to reboot.  A new hw_protection_trigger API then makes use of this
default action.

My particular use case is unattended embedded systems that don't have
support for shutdown and that power on automatically when power is
supplied:

  - A brief power cycle gets detected by the driver
  - The kernel powers down the system and SoC goes into shutdown mode
  - Power is restored
  - The system remains oblivious to the restored power
  - System needs to be manually power cycled for a duration long enough
    to drain the capacitors

With this series, such systems can configure the kernel with
hw_protection=reboot to have the boot firmware worry about critical
conditions.

This patch (of 12):

Currently __hw_protection_shutdown() either reboots or shuts down the
system according to its shutdown argument.

To make the logic easier to follow, both inside __hw_protection_shutdown
and at caller sites, lets replace the bool parameter with an enum.

This will be extra useful, when in a later commit, a third action is added
to the enumeration.

No functional change.

Link: https://lkml.kernel.org/r/20250217-hw_protection-reboot-v3-0-e1c09b090c0c@pengutronix.de
Link: https://lkml.kernel.org/r/20250217-hw_protection-reboot-v3-1-e1c09b090c0c@pengutronix.de
Signed-off-by: Ahmad Fatoum 
Reviewed-by: Tzung-Bi Shih 
Cc: Benson Leung 
Cc: Mark Brown 
Cc: Daniel Lezcano 
Cc: Fabio Estevam 
Cc: Guenter Roeck 
Cc: Jonathan Corbet 
Cc: Liam Girdwood 
Cc: Lukasz Luba 
Cc: Matteo Croce 
Cc: Matti Vaittinen 
Cc: "Rafael J. Wysocki" 
Cc: Rob Herring 
Cc: Rui Zhang 
Cc: Sascha Hauer 
Cc: "Serge E. Hallyn" 
Signed-off-by: Andrew Morton 
Stable-dep-of: bbf0ec4f57e0 ("reboot: reboot, not shutdown, on hw_protection_reboot timeout")
Signed-off-by: Sasha Levin

treewide: const qualify ctl_tables where applicable

2025-01-28T12:48:37+00:00

Add the const qualifier to all the ctl_tables in the tree except for
watchdog_hardlockup_sysctl, memory_allocation_profiling_sysctls,
loadpin_sysctl_table and the ones calling register_net_sysctl (./net,
drivers/inifiniband dirs). These are special cases as they use a
registration function with a non-const qualified ctl_table argument or
modify the arrays before passing them on to the registration function.

Constifying ctl_table structs will prevent the modification of
proc_handler function pointers as the arrays would reside in .rodata.
This is made possible after commit 78eb4ea25cd5 ("sysctl: treewide:
constify the ctl_table argument of proc_handlers") constified all the
proc_handlers.

Created this by running an spatch followed by a sed command:
Spatch:
    virtual patch

    @
    depends on !(file in "net")
    disable optional_qualifier
    @

    identifier table_name != {
      watchdog_hardlockup_sysctl,
      iwcm_ctl_table,
      ucma_ctl_table,
      memory_allocation_profiling_sysctls,
      loadpin_sysctl_table
    };
    @@

    + const
    struct ctl_table table_name [] = { ... };

sed:
    sed --in-place \
      -e "s/struct ctl_table .table = &uts_kern/const struct ctl_table *table = \&uts_kern/" \
      kernel/utsname_sysctl.c

Reviewed-by: Song Liu 
Acked-by: Steven Rostedt (Google)  # for kernel/trace/
Reviewed-by: Martin K. Petersen  # SCSI
Reviewed-by: Darrick J. Wong  # xfs
Acked-by: Jani Nikula 
Acked-by: Corey Minyard 
Acked-by: Wei Liu 
Acked-by: Thomas Gleixner 
Reviewed-by: Bill O'Donnell 
Acked-by: Baoquan He 
Acked-by: Ashutosh Dixit 
Acked-by: Anna Schumaker 
Signed-off-by: Joel Granados

kernel/reboot: replace sprintf() with sysfs_emit()

2024-11-12T01:17:05+00:00

As Documentation/filesystems/sysfs.rst suggested, show() should only use
sysfs_emit() or sysfs_emit_at() when formatting the value to be returned
to user space.

No functional change intended.

Link: https://lkml.kernel.org/r/20241105094941.33739-1-zhangguopeng@kylinos.cn
Signed-off-by: zhangguopeng 
Cc: Daniel Lezcano 
Cc: Fabio Estevam 
Cc: Joel Granados 
Cc: Thomas Weißschuh 
Signed-off-by: Andrew Morton

reboot: move reboot_notifier_list to kernel/reboot.c

2024-11-06T01:12:31+00:00

All the functions related to the reboot notifier list are in
kernel/reboot.c.  Move the list itself, too.  As there are no direct users
anymore, make the declaration static.

Link: https://lkml.kernel.org/r/20241012-reboot_notifier_list-v1-1-6093bb9455ce@weissschuh.net
Signed-off-by: Thomas Weißschuh 
Cc: Greg Kroah-Hartman 
Signed-off-by: Andrew Morton

kernel misc: Remove the now superfluous sentinel elements from ctl_table array

2024-04-24T07:43:53+00:00

This commit comes at the tail end of a greater effort to remove the
empty elements at the end of the ctl_table arrays (sentinels) which
will reduce the overall build time size of the kernel and run time
memory bloat by ~64 bytes per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/)

Remove the sentinel from ctl_table arrays. Reduce by one the values used
to compare the size of the adjusted arrays.

Signed-off-by: Joel Granados

Merge tag 'thermal-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2024-01-10T00:20:17+00:00

Pull thermal control updates from Rafael Wysocki:
 "These add support for the D1/T113s THS controller to the sun8i driver
  and a DT-based mechanism for platforms to indicate a preference to
  reboot (instead of shutting down) on crossing a critical trip point,
  fix issues, make other improvements (in the IPA governor, the Intel
  HFI driver, the exynos driver and the thermal netlink interface among
  other places) and clean up code.

  One long-standing issue addressed here is that trip point crossing
  notifications sent to user space might be unreliable due to the
  incorrect handling of trip point hysteresis in the thermal core:
  multiple notifications might be sent for the same event or there might
  be events without any notification at all.

  Specifics:

   - Add dynamic thresholds for trip point crossing detection to prevent
     trip point crossing notifications from being sent at incorrect
     times or not at all in some cases (Rafael J. Wysocki)

   - Fix synchronization issues related to the resume of thermal zones
     during a system-wide resume and allow thermal zones to be resumed
     concurrently (Rafael J. Wysocki)

   - Modify the thermal zone unregistration to wait for the given zone
     to go away completely before returning to the caller and rework the
     sysfs interface for trip points on top of that (Rafael J. Wysocki)

   - Fix a possible NULL pointer dereference in thermal zone
     registration error path (Rafael J. Wysocki)

   - Clean up the IPA thermal governor and modify it (with the help of a
     new governor callback) to avoid allocating and freeing memory every
     time its throttling callback is invoked (Lukasz Luba)

   - Make the IPA thermal governor handle thermal instance weight
     changes via sysfs correctly (Lukasz Luba)

   - Update the thermal netlink code to avoid sending messages if there
     are no recipients (Stanislaw Gruszka)

   - Convert Mediatek Thermal to the json-schema (Rafał Miłecki)

   - Fix thermal DT bindings issue on Loongson (Binbin Zhou)

   - Fix returning NULL instead of -ENODEV during thermal probe on
     Loogsoon (Binbin Zhou)

   - Add thermal DT binding for tsens on the SM8650 platform (Neil
     Armstrong)

   - Add reboot on the critical trip point crossing option feature
     (Fabio Estevam)

   - Use DEFINE_SIMPLE_DEV_PM_OPS do define PM functions for thermal
     suspend/resume on AmLogic (Uwe Kleine-König)

   - Add D1/T113s THS controller support to the Sun8i thermal control
     driver (Maxim Kiselev)

   - Fix example in the thermal DT binding for QCom SPMI (Johan Hovold)

   - Fix compilation warning in the tmon utility (Florian Eckert)

   - Add support for interrupt-based thermal configuration on Exynos
     along with a set of related cleanups (Mateusz Majewski)

   - Make the Intel HFI thermal driver enable an HFI instance (eg.
     processor package) from its first online CPU and disable it when
     the last CPU in it goes offline (Ricardo Neri)

   - Fix a kernel-doc warning and a spello in the cpuidle_cooling
     thermal driver (Randy Dunlap)

   - Move the .get_temp() thermal zone callback presence check to the
     thermal zone registration code (Daniel Lezcano)

   - Use the for_each_trip() macro for trip points table walks in a few
     places in the thermal core (Rafael J. Wysocki)

   - Make all trip point updates (via sysfs as well as from the platform
     firmware) trigger trip change notifications (Rafael J. Wysocki)

   - Drop redundant code from the thermal core and make one function in
     it take a const pointer argument (Rafael J. Wysocki)"

* tag 'thermal-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (64 commits)
  thermal: trip: Constify thermal zone argument of thermal_zone_trip_id()
  thermal: intel: hfi: Disable an HFI instance when all its CPUs go offline
  thermal: intel: hfi: Enable an HFI instance from its first online CPU
  thermal: intel: hfi: Refactor enabling code into helper functions
  thermal/drivers/exynos: Use set_trips ops
  thermal/drivers/exynos: Use BIT wherever possible
  thermal/drivers/exynos: Split initialization of TMU and the thermal zone
  thermal/drivers/exynos: Stop using the threshold mechanism on Exynos 4210
  thermal/drivers/exynos: Simplify regulator (de)initialization
  thermal/drivers/exynos: Handle devm_regulator_get_optional return value correctly
  thermal/drivers/exynos: Wwitch from workqueue-driven interrupt handling to threaded interrupts
  thermal/drivers/exynos: Drop id field
  thermal/drivers/exynos: Remove an unnecessary field description
  tools/thermal/tmon: Fix compilation warning for wrong format
  dt-bindings: thermal: qcom-spmi-adc-tm5/hc: Clean up examples
  dt-bindings: thermal: qcom-spmi-adc-tm5/hc: Fix example node names
  thermal/drivers/sun8i: Add D1/T113s THS controller support
  dt-bindings: thermal: sun8i: Add binding for D1/T113s THS controller
  thermal: amlogic: Use DEFINE_SIMPLE_DEV_PM_OPS for PM functions
  thermal: amlogic: Make amlogic_thermal_disable() return void
  ...

reboot: Introduce thermal_zone_device_critical_reboot()

2024-01-02T08:33:18+00:00

Introduce thermal_zone_device_critical_reboot() to trigger an
emergency reboot.

It is a counterpart of thermal_zone_device_critical() with the
difference that it will force a reboot instead of shutdown.

The motivation for doing this is to allow the thermal subystem
to trigger a reboot when the temperature reaches the critical
temperature.

Signed-off-by: Fabio Estevam 
Signed-off-by: Daniel Lezcano 
Link: https://lore.kernel.org/r/20231129124330.519423-3-festevam@gmail.com

thermal/core: Prepare for introduction of thermal reboot

2024-01-02T08:33:18+00:00

Add some helper functions to make it easier introducing the support
for thermal reboot.

No functional change.

Signed-off-by: Fabio Estevam 
Signed-off-by: Daniel Lezcano 
Link: https://lore.kernel.org/r/20231129124330.519423-2-festevam@gmail.com