linux-stable.git/kernel/time, branch v6.10.3 Linux kernel stable tree timers/migration: Do not rely always on group->parent 2024-08-03T07:01:06+00:00 Anna-Maria Behnsen anna-maria@linutronix.de 2024-07-16T14:19:19+00:00 00a60bdabefe0a63f7d5ef78e8ca85977e096583 [ Upstream commit facd40aa5c4699f94014012e4e58414c082f2c01 ] When reading group->parent without holding the group lock it is racy against CPUs coming online the first time and thereby creating another level of the hierarchy. This is not a problem when this value is read once to decide whether to abort a propagation or not. The worst outcome is an unnecessary/early CPU wake up. But it is racy when reading it several times during a single 'action' (like activation, deactivation, checking for remote timer expiry,...) and relying on the consitency of this value without holding the lock. This happens at the moment e.g. in tmigr_inactive_up() which is also calling tmigr_udpate_events(). Code relys on group->parent not to change during this 'action'. Update parent struct member description to explain the above only once. Remove parent pointer checks when they are not mandatory (like update of data->childmask). Remove a warning, which would be nice but the trigger of this warning is not reliable and add expand the data structure member description instead. Expand a comment, why it is safe to rely on parent pointer here (inside hierarchy update). Fixes: 7ee988770326 ("timers: Implement the hierarchical pull model") Reported-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20240716-tmigr-fixes-v4-1-757baa7803fe@linutronix.de Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit facd40aa5c4699f94014012e4e58414c082f2c01 ]

When reading group->parent without holding the group lock it is racy
against CPUs coming online the first time and thereby creating another
level of the hierarchy. This is not a problem when this value is read once
to decide whether to abort a propagation or not. The worst outcome is an
unnecessary/early CPU wake up. But it is racy when reading it several times
during a single 'action' (like activation, deactivation, checking for
remote timer expiry,...) and relying on the consitency of this value
without holding the lock. This happens at the moment e.g. in
tmigr_inactive_up() which is also calling tmigr_udpate_events(). Code relys
on group->parent not to change during this 'action'.

Update parent struct member description to explain the above only
once. Remove parent pointer checks when they are not mandatory (like update
of data->childmask). Remove a warning, which would be nice but the trigger
of this warning is not reliable and add expand the data structure member
description instead. Expand a comment, why it is safe to rely on parent
pointer here (inside hierarchy update).

Fixes: 7ee988770326 ("timers: Implement the hierarchical pull model")
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20240716-tmigr-fixes-v4-1-757baa7803fe@linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
tick/broadcast: Make takeover of broadcast hrtimer reliable 2024-08-03T07:00:30+00:00 Yu Liao liaoyu15@huawei.com 2024-07-11T12:48:43+00:00 2cdab4b4bf77369961f706cdeb7d040db10c5217 commit f7d43dd206e7e18c182f200e67a8db8c209907fa upstream. Running the LTP hotplug stress test on a aarch64 machine results in rcu_sched stall warnings when the broadcast hrtimer was owned by the un-plugged CPU. The issue is the following: CPU1 (owns the broadcast hrtimer) CPU2 tick_broadcast_enter() // shutdown local timer device broadcast_shutdown_local() ... tick_broadcast_exit() clockevents_switch_state(dev, CLOCK_EVT_STATE_ONESHOT) // timer device is not programmed cpumask_set_cpu(cpu, tick_broadcast_force_mask) initiates offlining of CPU1 take_cpu_down() /* * CPU1 shuts down and does not * send broadcast IPI anymore */ takedown_cpu() hotplug_cpu__broadcast_tick_pull() // move broadcast hrtimer to this CPU clockevents_program_event() bc_set_next() hrtimer_start() /* * timer device is not programmed * because only the first expiring * timer will trigger clockevent * device reprogramming */ What happens is that CPU2 exits broadcast mode with force bit set, then the local timer device is not reprogrammed and CPU2 expects to receive the expired event by the broadcast IPI. But this does not happen because CPU1 is offlined by CPU2. CPU switches the clockevent device to ONESHOT state, but does not reprogram the device. The subsequent reprogramming of the hrtimer broadcast device does not program the clockevent device of CPU2 either because the pending expiry time is already in the past and the CPU expects the event to be delivered. As a consequence all CPUs which wait for a broadcast event to be delivered are stuck forever. Fix this issue by reprogramming the local timer device if the broadcast force bit of the CPU is set so that the broadcast hrtimer is delivered. [ tglx: Massage comment and change log. Add Fixes tag ] Fixes: 989dcb645ca7 ("tick: Handle broadcast wakeup of multiple cpus") Signed-off-by: Yu Liao <liaoyu15@huawei.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240711124843.64167-1-liaoyu15@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit f7d43dd206e7e18c182f200e67a8db8c209907fa upstream.

Running the LTP hotplug stress test on a aarch64 machine results in
rcu_sched stall warnings when the broadcast hrtimer was owned by the
un-plugged CPU. The issue is the following:

CPU1 (owns the broadcast hrtimer)	CPU2

				tick_broadcast_enter()
				  // shutdown local timer device
				  broadcast_shutdown_local()
				...
				tick_broadcast_exit()
				  clockevents_switch_state(dev, CLOCK_EVT_STATE_ONESHOT)
				  // timer device is not programmed
				  cpumask_set_cpu(cpu, tick_broadcast_force_mask)

				initiates offlining of CPU1
take_cpu_down()
/*
 * CPU1 shuts down and does not
 * send broadcast IPI anymore
 */
				takedown_cpu()
				  hotplug_cpu__broadcast_tick_pull()
				    // move broadcast hrtimer to this CPU
				    clockevents_program_event()
				      bc_set_next()
					hrtimer_start()
					/*
					 * timer device is not programmed
					 * because only the first expiring
					 * timer will trigger clockevent
					 * device reprogramming
					 */

What happens is that CPU2 exits broadcast mode with force bit set, then the
local timer device is not reprogrammed and CPU2 expects to receive the
expired event by the broadcast IPI. But this does not happen because CPU1
is offlined by CPU2. CPU switches the clockevent device to ONESHOT state,
but does not reprogram the device.

The subsequent reprogramming of the hrtimer broadcast device does not
program the clockevent device of CPU2 either because the pending expiry
time is already in the past and the CPU expects the event to be delivered.
As a consequence all CPUs which wait for a broadcast event to be delivered
are stuck forever.

Fix this issue by reprogramming the local timer device if the broadcast
force bit of the CPU is set so that the broadcast hrtimer is delivered.

[ tglx: Massage comment and change log. Add Fixes tag ]

Fixes: 989dcb645ca7 ("tick: Handle broadcast wakeup of multiple cpus")
Signed-off-by: Yu Liao <liaoyu15@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240711124843.64167-1-liaoyu15@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
hrtimer: Prevent queuing of hrtimer without a function callback 2024-06-25T14:54:27+00:00 Phil Chang phil.chang@mediatek.com 2024-06-10T13:31:36+00:00 5a830bbce3af16833fe0092dec47b6dd30279825 The hrtimer function callback must not be NULL. It has to be specified by the call side but it is not validated by the hrtimer code. When a hrtimer is queued without a function callback, the kernel crashes with a null pointer dereference when trying to execute the callback in __run_hrtimer(). Introduce a validation before queuing the hrtimer in hrtimer_start_range_ns(). [anna-maria: Rephrase commit message] Signed-off-by: Phil Chang <phil.chang@mediatek.com> Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Anna-Maria Behnsen <anna-maria@linutronix.de> 
The hrtimer function callback must not be NULL. It has to be specified by
the call side but it is not validated by the hrtimer code. When a hrtimer
is queued without a function callback, the kernel crashes with a null
pointer dereference when trying to execute the callback in __run_hrtimer().

Introduce a validation before queuing the hrtimer in
hrtimer_start_range_ns().

[anna-maria: Rephrase commit message]

Signed-off-by: Phil Chang <phil.chang@mediatek.com>
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
tick/nohz_full: Don't abuse smp_call_function_single() in tick_setup_device() 2024-06-10T18:18:13+00:00 Oleg Nesterov oleg@redhat.com 2024-05-28T12:20:19+00:00 07c54cc5988f19c9642fd463c2dbdac7fc52f777 After the recent commit 5097cbcb38e6 ("sched/isolation: Prevent boot crash when the boot CPU is nohz_full") the kernel no longer crashes, but there is another problem. In this case tick_setup_device() calls tick_take_do_timer_from_boot() to update tick_do_timer_cpu and this triggers the WARN_ON_ONCE(irqs_disabled) in smp_call_function_single(). Kill tick_take_do_timer_from_boot() and just use WRITE_ONCE(), the new comment explains why this is safe (thanks Thomas!). Fixes: 08ae95f4fd3b ("nohz_full: Allow the boot CPU to be nohz_full") 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/20240528122019.GA28794@redhat.com Link: https://lore.kernel.org/all/20240522151742.GA10400@redhat.com 
After the recent commit 5097cbcb38e6 ("sched/isolation: Prevent boot crash
when the boot CPU is nohz_full") the kernel no longer crashes, but there is
another problem.

In this case tick_setup_device() calls tick_take_do_timer_from_boot() to
update tick_do_timer_cpu and this triggers the WARN_ON_ONCE(irqs_disabled)
in smp_call_function_single().

Kill tick_take_do_timer_from_boot() and just use WRITE_ONCE(), the new
comment explains why this is safe (thanks Thomas!).

Fixes: 08ae95f4fd3b ("nohz_full: Allow the boot CPU to be nohz_full")
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/20240528122019.GA28794@redhat.com
Link: https://lore.kernel.org/all/20240522151742.GA10400@redhat.com
Merge tag 'sysctl-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl 2024-05-18T00:31:24+00:00 Linus Torvalds torvalds@linux-foundation.org 2024-05-18T00:31:24+00:00 91b6163be404e36baea39fc978e4739fd0448ebd Pull sysctl updates from Joel Granados: - Remove sentinel elements from ctl_table structs in kernel/* Removing sentinels in ctl_table arrays reduces the build time size and runtime memory consumed by ~64 bytes per array. Removals for net/, io_uring/, mm/, ipc/ and security/ are set to go into mainline through their respective subsystems making the next release the most likely place where the final series that removes the check for proc_name == NULL will land. This adds to removals already in arch/, drivers/ and fs/. - Adjust ctl_table definitions and references to allow constification - Remove unused ctl_table function arguments - Move non-const elements from ctl_table to ctl_table_header - Make ctl_table pointers const in ctl_table_root structure Making the static ctl_table structs const will increase safety by keeping the pointers to proc_handler functions in .rodata. Though no ctl_tables where made const in this PR, the ground work for making that possible has started with these changes sent by Thomas Weißschuh. * tag 'sysctl-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl: sysctl: drop now unnecessary out-of-bounds check sysctl: move sysctl type to ctl_table_header sysctl: drop sysctl_is_perm_empty_ctl_table sysctl: treewide: constify argument ctl_table_root::permissions(table) sysctl: treewide: drop unused argument ctl_table_root::set_ownership(table) bpf: Remove the now superfluous sentinel elements from ctl_table array delayacct: Remove the now superfluous sentinel elements from ctl_table array kprobes: Remove the now superfluous sentinel elements from ctl_table array printk: Remove the now superfluous sentinel elements from ctl_table array scheduler: Remove the now superfluous sentinel elements from ctl_table array seccomp: Remove the now superfluous sentinel elements from ctl_table array timekeeping: Remove the now superfluous sentinel elements from ctl_table array ftrace: Remove the now superfluous sentinel elements from ctl_table array umh: Remove the now superfluous sentinel elements from ctl_table array kernel misc: Remove the now superfluous sentinel elements from ctl_table array 
Pull sysctl updates from Joel Granados:

 - Remove sentinel elements from ctl_table structs in kernel/*

   Removing sentinels in ctl_table arrays reduces the build time size
   and runtime memory consumed by ~64 bytes per array. Removals for
   net/, io_uring/, mm/, ipc/ and security/ are set to go into mainline
   through their respective subsystems making the next release the most
   likely place where the final series that removes the check for
   proc_name == NULL will land.

   This adds to removals already in arch/, drivers/ and fs/.

 - Adjust ctl_table definitions and references to allow constification
     - Remove unused ctl_table function arguments
     - Move non-const elements from ctl_table to ctl_table_header
     - Make ctl_table pointers const in ctl_table_root structure

   Making the static ctl_table structs const will increase safety by
   keeping the pointers to proc_handler functions in .rodata. Though no
   ctl_tables where made const in this PR, the ground work for making
   that possible has started with these changes sent by Thomas
   Weißschuh.

* tag 'sysctl-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl:
  sysctl: drop now unnecessary out-of-bounds check
  sysctl: move sysctl type to ctl_table_header
  sysctl: drop sysctl_is_perm_empty_ctl_table
  sysctl: treewide: constify argument ctl_table_root::permissions(table)
  sysctl: treewide: drop unused argument ctl_table_root::set_ownership(table)
  bpf: Remove the now superfluous sentinel elements from ctl_table array
  delayacct: Remove the now superfluous sentinel elements from ctl_table array
  kprobes: Remove the now superfluous sentinel elements from ctl_table array
  printk: Remove the now superfluous sentinel elements from ctl_table array
  scheduler: Remove the now superfluous sentinel elements from ctl_table array
  seccomp: Remove the now superfluous sentinel elements from ctl_table array
  timekeeping: Remove the now superfluous sentinel elements from ctl_table array
  ftrace: Remove the now superfluous sentinel elements from ctl_table array
  umh: Remove the now superfluous sentinel elements from ctl_table array
  kernel misc: Remove the now superfluous sentinel elements from ctl_table array
Merge tag 'timers-core-2024-05-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2024-05-14T16:27:40+00:00 Linus Torvalds torvalds@linux-foundation.org 2024-05-14T16:27:40+00:00 2d9db778ddca079228ef10e60bceea06b34b0eaa Pull timers and timekeeping updates from Thomas Gleixner: "Core code: - Make timekeeping and VDSO time readouts resilent against math overflow: In guest context the kernel is prone to math overflow when the host defers the timer interrupt due to overload, malfunction or malice. This can be mitigated by checking the clocksource delta for the maximum deferrement which is readily available. If that value is exceeded then the code uses a slowpath function which can handle the multiplication overflow. This functionality is enabled unconditionally in the kernel, but made conditional in the VDSO code. The latter is conditional because it allows architectures to optimize the check so it is not causing performance regressions. On X86 this is achieved by reworking the existing check for negative TSC deltas as a negative delta obviously exceeds the maximum deferrement when it is evaluated as an unsigned value. That avoids two conditionals in the hotpath and allows to hide both the negative delta and the large delta handling in the same slow path. - Add an initial minimal ktime_t abstraction for Rust - The usual boring cleanups and enhancements Drivers: - Boring updates to device trees and trivial enhancements in various drivers" * tag 'timers-core-2024-05-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits) clocksource/drivers/arm_arch_timer: Mark hisi_161010101_oem_info const clocksource/drivers/timer-ti-dm: Remove an unused field in struct dmtimer clocksource/drivers/renesas-ostm: Avoid reprobe after successful early probe clocksource/drivers/renesas-ostm: Allow OSTM driver to reprobe for RZ/V2H(P) SoC dt-bindings: timer: renesas: ostm: Document Renesas RZ/V2H(P) SoC rust: time: doc: Add missing C header links clocksource: Make the int help prompt unit readable in ncurses hrtimer: Rename __hrtimer_hres_active() to hrtimer_hres_active() timerqueue: Remove never used function timerqueue_node_expires() rust: time: Add Ktime vdso: Fix powerpc build U64_MAX undeclared error clockevents: Convert s[n]printf() to sysfs_emit() clocksource: Convert s[n]printf() to sysfs_emit() clocksource: Make watchdog and suspend-timing multiplication overflow safe timekeeping: Let timekeeping_cycles_to_ns() handle both under and overflow timekeeping: Make delta calculation overflow safe timekeeping: Prepare timekeeping_cycles_to_ns() for overflow safety timekeeping: Fold in timekeeping_delta_to_ns() timekeeping: Consolidate timekeeping helpers timekeeping: Refactor timekeeping helpers ... 
Pull timers and timekeeping updates from Thomas Gleixner:
 "Core code:

   - Make timekeeping and VDSO time readouts resilent against math
     overflow:

     In guest context the kernel is prone to math overflow when the host
     defers the timer interrupt due to overload, malfunction or malice.

     This can be mitigated by checking the clocksource delta for the
     maximum deferrement which is readily available. If that value is
     exceeded then the code uses a slowpath function which can handle
     the multiplication overflow.

     This functionality is enabled unconditionally in the kernel, but
     made conditional in the VDSO code. The latter is conditional
     because it allows architectures to optimize the check so it is not
     causing performance regressions.

     On X86 this is achieved by reworking the existing check for
     negative TSC deltas as a negative delta obviously exceeds the
     maximum deferrement when it is evaluated as an unsigned value. That
     avoids two conditionals in the hotpath and allows to hide both the
     negative delta and the large delta handling in the same slow path.

   - Add an initial minimal ktime_t abstraction for Rust

   - The usual boring cleanups and enhancements

  Drivers:

   - Boring updates to device trees and trivial enhancements in various
     drivers"

* tag 'timers-core-2024-05-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
  clocksource/drivers/arm_arch_timer: Mark hisi_161010101_oem_info const
  clocksource/drivers/timer-ti-dm: Remove an unused field in struct dmtimer
  clocksource/drivers/renesas-ostm: Avoid reprobe after successful early probe
  clocksource/drivers/renesas-ostm: Allow OSTM driver to reprobe for RZ/V2H(P) SoC
  dt-bindings: timer: renesas: ostm: Document Renesas RZ/V2H(P) SoC
  rust: time: doc: Add missing C header links
  clocksource: Make the int help prompt unit readable in ncurses
  hrtimer: Rename __hrtimer_hres_active() to hrtimer_hres_active()
  timerqueue: Remove never used function timerqueue_node_expires()
  rust: time: Add Ktime
  vdso: Fix powerpc build U64_MAX undeclared error
  clockevents: Convert s[n]printf() to sysfs_emit()
  clocksource: Convert s[n]printf() to sysfs_emit()
  clocksource: Make watchdog and suspend-timing multiplication overflow safe
  timekeeping: Let timekeeping_cycles_to_ns() handle both under and overflow
  timekeeping: Make delta calculation overflow safe
  timekeeping: Prepare timekeeping_cycles_to_ns() for overflow safety
  timekeeping: Fold in timekeeping_delta_to_ns()
  timekeeping: Consolidate timekeeping helpers
  timekeeping: Refactor timekeeping helpers
  ...
Merge tag 'sched-core-2024-05-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2024-05-14T00:18:51+00:00 Linus Torvalds torvalds@linux-foundation.org 2024-05-14T00:18:51+00:00 6e5a0c30b616bfff6926ecca5d88e3d06e6bf79a Pull scheduler updates from Ingo Molnar: - Add cpufreq pressure feedback for the scheduler - Rework misfit load-balancing wrt affinity restrictions - Clean up and simplify the code around ::overutilized and ::overload access. - Simplify sched_balance_newidle() - Bump SCHEDSTAT_VERSION to 16 due to a cleanup of CPU_MAX_IDLE_TYPES handling that changed the output. - Rework & clean up <asm/vtime.h> interactions wrt arch_vtime_task_switch() - Reorganize, clean up and unify most of the higher level scheduler balancing function names around the sched_balance_*() prefix - Simplify the balancing flag code (sched_balance_running) - Miscellaneous cleanups & fixes * tag 'sched-core-2024-05-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (50 commits) sched/pelt: Remove shift of thermal clock sched/cpufreq: Rename arch_update_thermal_pressure() => arch_update_hw_pressure() thermal/cpufreq: Remove arch_update_thermal_pressure() sched/cpufreq: Take cpufreq feedback into account cpufreq: Add a cpufreq pressure feedback for the scheduler sched/fair: Fix update of rd->sg_overutilized sched/vtime: Do not include <asm/vtime.h> header s390/irq,nmi: Include <asm/vtime.h> header directly s390/vtime: Remove unused __ARCH_HAS_VTIME_TASK_SWITCH leftover sched/vtime: Get rid of generic vtime_task_switch() implementation sched/vtime: Remove confusing arch_vtime_task_switch() declaration sched/balancing: Simplify the sg_status bitmask and use separate ->overloaded and ->overutilized flags sched/fair: Rename set_rd_overutilized_status() to set_rd_overutilized() sched/fair: Rename SG_OVERLOAD to SG_OVERLOADED sched/fair: Rename {set|get}_rd_overload() to {set|get}_rd_overloaded() sched/fair: Rename root_domain::overload to ::overloaded sched/fair: Use helper functions to access root_domain::overload sched/fair: Check root_domain::overload value before update sched/fair: Combine EAS check with root_domain::overutilized access sched/fair: Simplify the continue_balancing logic in sched_balance_newidle() ... 
Pull scheduler updates from Ingo Molnar:

 - Add cpufreq pressure feedback for the scheduler

 - Rework misfit load-balancing wrt affinity restrictions

 - Clean up and simplify the code around ::overutilized and
   ::overload access.

 - Simplify sched_balance_newidle()

 - Bump SCHEDSTAT_VERSION to 16 due to a cleanup of CPU_MAX_IDLE_TYPES
   handling that changed the output.

 - Rework & clean up <asm/vtime.h> interactions wrt arch_vtime_task_switch()

 - Reorganize, clean up and unify most of the higher level
   scheduler balancing function names around the sched_balance_*()
   prefix

 - Simplify the balancing flag code (sched_balance_running)

 - Miscellaneous cleanups & fixes

* tag 'sched-core-2024-05-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (50 commits)
  sched/pelt: Remove shift of thermal clock
  sched/cpufreq: Rename arch_update_thermal_pressure() => arch_update_hw_pressure()
  thermal/cpufreq: Remove arch_update_thermal_pressure()
  sched/cpufreq: Take cpufreq feedback into account
  cpufreq: Add a cpufreq pressure feedback for the scheduler
  sched/fair: Fix update of rd->sg_overutilized
  sched/vtime: Do not include <asm/vtime.h> header
  s390/irq,nmi: Include <asm/vtime.h> header directly
  s390/vtime: Remove unused __ARCH_HAS_VTIME_TASK_SWITCH leftover
  sched/vtime: Get rid of generic vtime_task_switch() implementation
  sched/vtime: Remove confusing arch_vtime_task_switch() declaration
  sched/balancing: Simplify the sg_status bitmask and use separate ->overloaded and ->overutilized flags
  sched/fair: Rename set_rd_overutilized_status() to set_rd_overutilized()
  sched/fair: Rename SG_OVERLOAD to SG_OVERLOADED
  sched/fair: Rename {set|get}_rd_overload() to {set|get}_rd_overloaded()
  sched/fair: Rename root_domain::overload to ::overloaded
  sched/fair: Use helper functions to access root_domain::overload
  sched/fair: Check root_domain::overload value before update
  sched/fair: Combine EAS check with root_domain::overutilized access
  sched/fair: Simplify the continue_balancing logic in sched_balance_newidle()
  ...
timers/migration: Prevent out of bounds access on failure 2024-05-08T09:19:43+00:00 Levi Yun ppbuk5246@gmail.com 2024-05-06T04:10:59+00:00 d7ad05c86e2191bd66e5b62fca8da53c4a53484f When tmigr_setup_groups() fails the level 0 group allocation, then the cleanup derefences index -1 of the local stack array. Prevent this by checking the loop condition first. Fixes: 7ee988770326 ("timers: Implement the hierarchical pull model") Signed-off-by: Levi Yun <ppbuk5246@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Link: https://lore.kernel.org/r/20240506041059.86877-1-ppbuk5246@gmail.com 
When tmigr_setup_groups() fails the level 0 group allocation, then the
cleanup derefences index -1 of the local stack array.

Prevent this by checking the loop condition first.

Fixes: 7ee988770326 ("timers: Implement the hierarchical pull model")
Signed-off-by: Levi Yun <ppbuk5246@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Link: https://lore.kernel.org/r/20240506041059.86877-1-ppbuk5246@gmail.com
clocksource: Make the int help prompt unit readable in ncurses 2024-04-29T22:12:22+00:00 Borislav Petkov (AMD) bp@alien8.de 2024-04-28T10:21:43+00:00 54db412e618e9c43e5167f809a901f554e8c43e2 When doing make menuconfig and searching for the CLOCKSOURCE_WATCHDOG_MAX_SKEW_US config item, the help says: │ Symbol: CLOCKSOURCE_WATCHDOG_MAX_SKEW_US [=125] │ Type : integer │ Range : [50 1000] │ Defined at kernel/time/Kconfig:204 │ Prompt: Clocksource watchdog maximum allowable skew (in s) ^^^ │ Depends on: GENERIC_CLOCKEVENTS [=y] && CLOCKSOURCE_WATCHDOG [=y] because on some terminals, it cannot display the 'μ' char, unicode number 0x3bc. So simply write it out so that there's no trouble. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Paul E. McKenney <paulmck@kernel.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/20240428102143.26764-1-bp@kernel.org 
When doing

  make menuconfig

and searching for the CLOCKSOURCE_WATCHDOG_MAX_SKEW_US config item, the
help says:

  │ Symbol: CLOCKSOURCE_WATCHDOG_MAX_SKEW_US [=125]
  │ Type  : integer
  │ Range : [50 1000]
  │ Defined at kernel/time/Kconfig:204
  │   Prompt: Clocksource watchdog maximum allowable skew (in   s)
  							      ^^^

  │   Depends on: GENERIC_CLOCKEVENTS [=y] && CLOCKSOURCE_WATCHDOG [=y]

because on some terminals, it cannot display the 'μ' char, unicode
number 0x3bc.

So simply write it out so that there's no trouble.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20240428102143.26764-1-bp@kernel.org
timekeeping: Remove the now superfluous sentinel elements from ctl_table array 2024-04-24T07:43:54+00:00 Joel Granados j.granados@samsung.com 2023-06-27T13:30:23+00:00 fe6fc8e11b5a118a299c0d8f06407794173e6aa9 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 sentinel element from time_sysctl Signed-off-by: Joel Granados <j.granados@samsung.com> 
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 sentinel element from time_sysctl

Signed-off-by: Joel Granados <j.granados@samsung.com>