Rafael J. Wysocki ad3a999b8b 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 [ bw_min => bw_dl ] Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2025-09-09 18:54:18 +02:00
..
bpf	bpf: Fix oob access in cgroup local storage	2025-09-09 18:54:11 +02:00
cgroup	cgroup/cpuset: Use static_branch_enable_cpuslocked() on cpusets_insane_config_key	2025-08-28 16:26:17 +02:00
configs
debug	kdb: Do not assume write() callback available	2025-02-21 13:50:09 +01:00
dma	dma/pool: Ensure DMA_DIRECT_REMAP allocations are decrypted	2025-09-04 15:26:30 +02:00
entry	entry: Respect changes to system call number by trace_sys_enter()	2024-04-03 15:19:44 +02:00
events	perf/core: Prevent VMA split of buffer mappings	2025-08-15 12:05:11 +02:00
futex	futex: Don't include process MM in futex key on no-MMU	2023-11-20 11:51:50 +01:00
gcov	gcov: add support for GCC 14	2024-06-27 13:46:22 +02:00
irq	genirq: Make handle_enforce_irqctx() unconditionally available	2025-02-21 13:48:57 +01:00
kcsan	kcsan: test: Initialize dummy variable	2025-08-15 12:04:59 +02:00
livepatch	livepatch: Fix missing newline character in klp_resolve_symbols()	2023-11-20 11:52:10 +01:00
locking	locking/lockdep: Decrease nr_unused_locks if lock unused in zap_class()	2025-04-25 10:43:41 +02:00
module	module: Prevent silent truncation of module name in delete_module(2)	2025-08-28 16:26:01 +02:00
power	PM: sleep: console: Fix the black screen issue	2025-08-28 16:25:53 +02:00
printk	printk: Fix signed integer overflow when defining LOG_BUF_LEN_MAX	2025-02-21 13:49:30 +01:00
rcu	rcu: Protect ->defer_qs_iw_pending from data race	2025-08-28 16:25:55 +02:00
sched	cpufreq/sched: Explicitly synchronize limits_changed flag handling	2025-09-09 18:54:18 +02:00
time	clocksource: Fix the CPUs' choice in the watchdog per CPU verification	2025-06-27 11:07:31 +01:00
trace	ftrace: Fix potential warning in trace_printk_seq during ftrace_dump	2025-09-04 15:26:24 +02:00
.gitignore
acct.c	acct: block access to kernel internal filesystems	2025-03-07 16:56:39 +01:00
async.c	async: Introduce async_schedule_dev_nocall()	2024-01-31 16:17:00 -08:00
audit_fsnotify.c
audit_tree.c
audit_watch.c	audit: don't WARN_ON_ONCE(!current->mm) in audit_exe_compare()	2023-11-28 17:07:08 +00:00
audit.c	audit: Send netlink ACK before setting connection in auditd_set	2024-02-05 20:12:47 +00:00
audit.h
auditfilter.c	ima: Avoid blocking in RCU read-side critical section	2024-07-11 12:47:16 +02:00
auditsc.c	audit,io_uring: io_uring openat triggers audit reference count underflow	2023-10-25 12:03:04 +02:00
backtracetest.c
bounds.c	bounds: Use the right number of bits for power-of-two CONFIG_NR_CPUS	2024-05-02 16:29:32 +02:00
capability.c
cfi.c
compat.c	sched_getaffinity: don't assume 'cpumask_size()' is fully initialized	2023-04-06 12:10:40 +02:00
configs.c
context_tracking.c	context_tracking: Fix noinstr vs KASAN	2023-03-10 09:33:45 +01:00
cpu_pm.c
cpu.c	hrtimers: Handle CPU state correctly on hotplug	2025-01-23 17:17:15 +01:00
crash_core.c
crash_dump.c
cred.c	cred: switch to using atomic_long_t	2023-12-20 17:00:20 +01:00
delayacct.c
dma.c
exec_domain.c
exit.c	perf: Fix sample vs do_exit()	2025-06-27 11:07:41 +01:00
extable.c
fail_function.c	kernel/fail_function: fix memory leak with using debugfs_lookup()	2023-03-11 13:55:39 +01:00
fork.c	mm: drop the assumption that VM_SHARED always implies writable	2025-08-28 16:26:12 +02:00
freezer.c
gen_kheaders.sh	kheaders: Ignore silly-rename files	2025-01-23 17:17:11 +01:00
groups.c
hung_task.c
iomem.c
irq_work.c
jump_label.c	jump_label: Fix static_key_slow_dec() yet again	2024-10-17 15:21:29 +02:00
kallsyms_internal.h	kallsyms: Reduce the memory occupied by kallsyms_seqs_of_names[]	2023-10-25 12:03:16 +02:00
kallsyms.c	kallsyms: Add helper kallsyms_on_each_match_symbol()	2023-10-25 12:03:16 +02:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c	kcov: mark in_softirq_really() as __always_inline	2025-01-09 13:30:05 +01:00
kexec_core.c	kexec: fix a memory leak in crash_shrink_memory()	2023-07-19 16:21:08 +02:00
kexec_elf.c	kexec: initialize ELF lowest address to ULONG_MAX	2025-04-10 14:33:36 +02:00
kexec_file.c	kexec: support purgatories with .text.hot sections	2023-06-21 16:00:55 +02:00
kexec_internal.h
kexec.c	kernel: kexec: copy user-array safely	2023-11-28 17:06:57 +00:00
kheaders.c	kheaders: Use array declaration instead of char	2023-05-11 23:03:02 +09:00
kmod.c
kprobes.c	kprobes: Fix to check symbol prefixes correctly	2024-08-14 13:52:54 +02:00
ksysfs.c
kthread.c	kthread: unpark only parked kthread	2024-10-17 15:22:28 +02:00
latencytop.c
Makefile	kernel/numa.c: Move logging out of numa.h	2024-06-12 11:03:16 +02:00
module_signature.c
notifier.c
nsproxy.c
numa.c	kernel/numa.c: Move logging out of numa.h	2024-06-12 11:03:16 +02:00
padata.c	padata: do not leak refcount in reorder_work	2025-06-04 14:40:20 +02:00
panic.c	panic: Flush kernel log buffer at the end	2024-04-13 13:04:54 +02:00
params.c	module: ensure that kobject_put() is safe for module type kobjects	2025-05-18 08:21:23 +02:00
pid_namespace.c	pid: Replace struct pid 1-element array with flex-array	2024-08-29 17:30:18 +02:00
pid.c	pid: add pidfd_prepare()	2025-06-04 14:40:25 +02:00
profile.c	profiling: remove profile=sleep support	2024-08-14 13:52:50 +02:00
ptrace.c
range.c
reboot.c	kernel/reboot: emergency_restart: Set correct system_state	2023-11-28 17:07:13 +00:00
regset.c
relay.c	relayfs: fix out-of-bounds access in relay_file_read	2023-05-11 23:03:03 +09:00
resource_kunit.c
resource.c	resource: fix region_intersects() vs add_memory_driver_managed()	2024-10-17 15:21:55 +02:00
rseq.c	rseq: Fix segfault on registration when rseq_cs is non-zero	2025-07-17 18:32:15 +02:00
scftorture.c	scftorture: Forgive memory-allocation failure if KASAN	2023-09-23 11:11:00 +02:00
scs.c
seccomp.c
signal.c	signal: restore the override_rlimit logic	2024-11-14 13:15:18 +01:00
smp.c	smp: Add missing destroy_work_on_stack() call in smp_call_on_cpu()	2024-09-12 11:10:24 +02:00
smpboot.c
smpboot.h
softirq.c	lockdep: Fix wait context check on softirq for PREEMPT_RT	2025-06-04 14:40:03 +02:00
stackleak.c
stacktrace.c
static_call_inline.c	x86/static-call: provide a way to do very early static-call updates	2024-12-19 18:08:58 +01:00
static_call.c
stop_machine.c
sys_ni.c	syscalls: fix compat_sys_io_pgetevents_time64 usage	2024-07-05 09:31:59 +02:00
sys.c	hrtimer: Use and report correct timerslack values for realtime tasks	2025-03-28 21:58:48 +01:00
sysctl-test.c
sysctl.c
task_work.c	task_work: Introduce task_work_cancel() again	2024-08-03 08:49:34 +02:00
taskstats.c
torture.c	torture: Fix hang during kthread shutdown phase	2023-03-10 09:34:07 +01:00
tracepoint.c
tsacct.c
ucount.c	ucount: fix atomic_long_inc_below() argument type	2025-08-15 12:05:05 +02:00
uid16.c
uid16.h
umh.c	freezer,umh: Fix call_usermode_helper_exec() vs SIGKILL	2023-02-22 12:59:50 +01:00
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 14:33:30 +02:00
watchdog_hld.c	watchdog/perf: properly initialize the turbo mode timestamp and rearm counter	2024-08-03 08:49:42 +02:00
watchdog.c	watchdog: move softlockup_panic back to early_param	2023-11-28 17:07:09 +00:00
workqueue_internal.h
workqueue.c	workqueue: Improve scalability of workqueue watchdog touch	2024-09-12 11:10:27 +02:00