Rafael J. Wysocki 2075ccfcba cpufreq/sched: Explicitly synchronize limits_changed flag handling ... [ Upstream commit 79443a7e9d ] The handling of the limits_changed flag in struct sugov_policy needs to be explicitly synchronized to ensure that cpufreq policy limits updates will not be missed in some cases. Without that synchronization it is theoretically possible that the limits_changed update in sugov_should_update_freq() will be reordered with respect to the reads of the policy limits in cpufreq_driver_resolve_freq() and in that case, if the limits_changed update in sugov_limits() clobbers the one in sugov_should_update_freq(), the new policy limits may not take effect for a long time. Likewise, the limits_changed update in sugov_limits() may theoretically get reordered with respect to the updates of the policy limits in cpufreq_set_policy() and if sugov_should_update_freq() runs between them, the policy limits change may be missed. To ensure that the above situations will not take place, add memory barriers preventing the reordering in question from taking place and add READ_ONCE() and WRITE_ONCE() annotations around all of the limits_changed flag updates to prevent the compiler from messing up with that code. Fixes: 600f5badb7 ("cpufreq: schedutil: Don't skip freq update when limits change") Cc: 5.3+ <stable@vger.kernel.org> # 5.3+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Christian Loehle <christian.loehle@arm.com> Link: https://patch.msgid.link/3376719.44csPzL39Z@rjwysocki.net [ Adjust context ] Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2025-09-09 18:45:22 +02:00
..
bpf	bpf: fix precision backtracking instruction iteration	2025-06-27 11:04:25 +01:00
cgroup	cgroup/cpuset: Use static_branch_enable_cpuslocked() on cpusets_insane_config_key	2025-08-28 16:22:58 +02:00
configs
debug	kdb: Do not assume write() callback available	2025-03-13 12:47:22 +01:00
dma	dma/pool: Ensure DMA_DIRECT_REMAP allocations are decrypted	2025-09-04 14:41:44 +02:00
entry	entry/kvm: Exit to user mode when TIF_NOTIFY_SIGNAL is set	2023-01-04 11:39:22 +01:00
events	perf/core: Prevent VMA split of buffer mappings	2025-08-28 16:22:38 +02:00
futex	futex: Don't include process MM in futex key on no-MMU	2023-11-20 11:06:44 +01:00
gcov	gcov: add support for GCC 14	2024-07-05 09:12:41 +02:00
irq	genirq: Make handle_enforce_irqctx() unconditionally available	2025-03-13 12:46:45 +01:00
kcsan	kcsan: Turn report_filterlist_lock into a raw_spinlock	2024-12-14 19:48:25 +01:00
livepatch	kallsyms: refactor {,module_}kallsyms_on_each_symbol	2024-06-21 14:52:58 +02:00
locking	locking/lockdep: Decrease nr_unused_locks if lock unused in zap_class()	2025-05-02 07:40:55 +02:00
power	PM: sleep: console: Fix the black screen issue	2025-08-28 16:22:41 +02:00
printk	printk: Fix signed integer overflow when defining LOG_BUF_LEN_MAX	2025-03-13 12:47:01 +01:00
rcu	rcu: Protect ->defer_qs_iw_pending from data race	2025-08-28 16:22:42 +02:00
sched	cpufreq/sched: Explicitly synchronize limits_changed flag handling	2025-09-09 18:45:22 +02:00
time	clocksource: Fix the CPUs' choice in the watchdog per CPU verification	2025-06-27 11:04:15 +01:00
trace	ftrace: Fix potential warning in trace_printk_seq during ftrace_dump	2025-09-04 14:41:41 +02:00
.gitignore
acct.c	acct: perform last write from workqueue	2025-03-13 12:47:35 +01:00
async.c	async: Introduce async_schedule_dev_nocall()	2024-02-23 08:41:53 +01:00
audit_fsnotify.c	fsnotify: make allow_dups a property of the group	2024-06-21 14:53:39 +02:00
audit_tree.c	fsnotify: pass flags argument to fsnotify_alloc_group()	2024-06-21 14:53:39 +02:00
audit_watch.c	fsnotify: pass flags argument to fsnotify_alloc_group()	2024-06-21 14:53:39 +02:00
audit.c	audit: Send netlink ACK before setting connection in auditd_set	2024-02-23 08:42:03 +01:00
audit.h	audit: log AUDIT_TIME_* records only from rules	2022-04-08 14:40:00 +02:00
auditfilter.c	ima: Avoid blocking in RCU read-side critical section	2024-07-18 13:05:44 +02:00
auditsc.c	audit: fix possible soft lockup in __audit_inode_child()	2023-09-19 12:20:13 +02:00
backtracetest.c
bounds.c	bounds: Use the right number of bits for power-of-two CONFIG_NR_CPUS	2024-05-02 16:23:46 +02:00
capability.c
compat.c	sched_getaffinity: don't assume 'cpumask_size()' is fully initialized	2023-04-05 11:23:45 +02:00
configs.c
context_tracking.c
cpu_pm.c	PM: cpu: Make notifier chain use a raw_spinlock_t	2021-09-15 09:50:40 +02:00
cpu.c	hrtimers: Handle CPU state correctly on hotplug	2025-02-01 18:22:29 +01:00
crash_core.c
crash_dump.c
cred.c	cred: switch to using atomic_long_t	2023-12-20 15:44:30 +01:00
delayacct.c
dma.c
exec_domain.c
exit.c	perf: Fix sample vs do_exit()	2025-06-27 11:04:24 +01:00
extable.c
fail_function.c	kernel/fail_function: fix memory leak with using debugfs_lookup()	2023-03-11 16:40:18 +01:00
fork.c	mm: drop the assumption that VM_SHARED always implies writable	2025-08-28 16:22:54 +02:00
freezer.c
gen_kheaders.sh	kheaders: Ignore silly-rename files	2025-02-01 18:22:28 +01:00
groups.c
hung_task.c
iomem.c
irq_work.c
jump_label.c
kallsyms.c	kallsyms: Make kallsyms_on_each_symbol generally available	2024-10-17 15:08:29 +02:00
kcmp.c	kcmp: In get_file_raw_ptr use task_lookup_fd_rcu	2024-06-21 14:52:48 +02:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c	kcov: don't lose track of remote references during softirqs	2024-07-05 09:12:41 +02:00
kexec_core.c	kexec: fix a memory leak in crash_shrink_memory()	2023-07-27 08:43:40 +02:00
kexec_elf.c	kexec: initialize ELF lowest address to ULONG_MAX	2025-04-10 14:30:58 +02:00
kexec_file.c	kexec: support purgatories with .text.hot sections	2023-06-21 15:45:37 +02:00
kexec_internal.h	panic, kexec: make __crash_kexec() NMI safe	2023-04-20 12:10:29 +02:00
kexec.c	panic, kexec: make __crash_kexec() NMI safe	2023-04-20 12:10:29 +02:00
kheaders.c	kheaders: Use array declaration instead of char	2023-05-17 11:47:33 +02:00
kmod.c
kprobes.c	x86/ibt,ftrace: Search for __fentry__ location	2024-10-17 15:07:37 +02:00
ksysfs.c	kexec: turn all kexec_mutex acquisitions into trylocks	2023-04-20 12:10:29 +02:00
kthread.c	kthread: fix task state in kthread worker if being frozen	2024-10-17 15:07:50 +02:00
latencytop.c
Makefile	futex: Move to kernel/futex/	2023-01-14 10:15:20 +01:00
module_signature.c
module_signing.c
module-internal.h
module.c	kallsyms: Make module_kallsyms_on_each_symbol generally available	2024-10-17 15:08:29 +02:00
notifier.c
nsproxy.c
padata.c	padata: do not leak refcount in reorder_work	2025-06-04 14:37:07 +02:00
panic.c	panic: Flush kernel log buffer at the end	2024-04-13 12:59:40 +02:00
params.c	module: ensure that kobject_put() is safe for module type kobjects	2025-06-04 14:36:55 +02:00
pid_namespace.c	zap_pid_ns_processes: clear TIF_NOTIFY_SIGNAL along with TIF_SIGPENDING	2024-07-05 09:12:33 +02:00
pid.c	kernel/pid.c: implement additional checks upon pidfd_create() parameters	2024-06-21 14:53:17 +02:00
profile.c	kernel: Initialize cpumask before parsing	2025-01-09 13:25:04 +01:00
ptrace.c	ptrace: Reimplement PTRACE_KILL by always sending SIGKILL	2022-06-09 10:20:49 +02:00
range.c
reboot.c	kernel/reboot: emergency_restart: Set correct system_state	2023-11-28 16:54:58 +00:00
regset.c
relay.c	relayfs: fix out-of-bounds access in relay_file_read	2023-05-17 11:47:34 +02:00
resource.c	kernel/resource: fix kfree() of bootmem memory again	2025-05-02 07:41:09 +02:00
rseq.c	rseq: Fix segfault on registration when rseq_cs is non-zero	2025-07-17 18:28:01 +02:00
scftorture.c	scftorture: Forgive memory-allocation failure if KASAN	2023-09-23 11:01:05 +02:00
scs.c
seccomp.c	seccomp: Invalidate seccomp mode to catch death failures	2024-03-01 13:16:46 +01:00
signal.c	signal: Replace BUG_ON()s	2024-10-17 15:08:12 +02:00
smp.c	smp: Add missing destroy_work_on_stack() call in smp_call_on_cpu()	2024-09-12 11:06:48 +02:00
smpboot.c
smpboot.h
softirq.c
stackleak.c	gcc-plugins/stackleak: Use noinstr in favor of notrace	2022-02-23 12:01:00 +01:00
stacktrace.c
static_call.c	x86/static-call: provide a way to do very early static-call updates	2024-12-19 18:06:13 +01:00
stop_machine.c
sys_ni.c	syscalls: fix compat_sys_io_pgetevents_time64 usage	2024-07-05 09:12:55 +02:00
sys.c	fs: add file and path permissions helpers	2024-06-21 14:52:58 +02:00
sysctl-test.c
sysctl.c	sysctl: introduce new proc handler proc_dobool	2024-06-21 14:53:18 +02:00
task_work.c	task_work: Introduce task_work_cancel() again	2024-08-19 05:40:57 +02:00
taskstats.c
test_kprobes.c
torture.c	torture: Fix hang during kthread shutdown phase	2023-08-30 16:23:17 +02:00
tracepoint.c
tsacct.c	taskstats: Cleanup the use of task->exit_code	2022-01-27 10:54:33 +01:00
ucount.c	fanotify: configurable limits via sysfs	2024-06-21 14:53:06 +02:00
uid16.c
uid16.h
umh.c
up.c
user_namespace.c
user-return-notifier.c
user.c
usermode_driver.c
utsname_sysctl.c
utsname.c
watch_queue.c	watch_queue: fix pipe accounting mismatch	2025-04-10 14:30:55 +02:00
watchdog_hld.c	watchdog/perf: properly initialize the turbo mode timestamp and rearm counter	2024-08-19 05:41:01 +02:00
watchdog.c	watchdog: move softlockup_panic back to early_param	2023-11-28 16:54:56 +00:00
workqueue_internal.h
workqueue.c	Revert "workqueue: remove unused cancel_work()"	2023-12-08 08:46:13 +01:00