android_kernel_motorola_sm6375/kernel
Repository files (latest commit first)
Filename Latest commit message Latest commit date
Chen Ridong cabadd7fd1 cgroup: split cgroup_destroy_wq into 3 workqueues
[ Upstream commit 79f919a89c9d06816dbdbbd168fa41d27411a7f9 ]

A hung task can occur during [1] LTP cgroup testing when repeatedly
mounting/unmounting perf_event and net_prio controllers with
systemd.unified_cgroup_hierarchy=1. The hang manifests in
cgroup_lock_and_drain_offline() during root destruction.

Related case:
cgroup_fj_function_perf_event cgroup_fj_function.sh perf_event
cgroup_fj_function_net_prio cgroup_fj_function.sh net_prio

Call Trace:
	cgroup_lock_and_drain_offline+0x14c/0x1e8
	cgroup_destroy_root+0x3c/0x2c0
	css_free_rwork_fn+0x248/0x338
	process_one_work+0x16c/0x3b8
	worker_thread+0x22c/0x3b0
	kthread+0xec/0x100
	ret_from_fork+0x10/0x20

Root Cause:

CPU0                            CPU1
mount perf_event                umount net_prio
cgroup1_get_tree                cgroup_kill_sb
rebind_subsystems               // root destruction enqueues
				// cgroup_destroy_wq
// kill all perf_event css
                                // one perf_event css A is dying
                                // css A offline enqueues cgroup_destroy_wq
                                // root destruction will be executed first
                                css_free_rwork_fn
                                cgroup_destroy_root
                                cgroup_lock_and_drain_offline
                                // some perf descendants are dying
                                // cgroup_destroy_wq max_active = 1
                                // waiting for css A to die

Problem scenario:
1. CPU0 mounts perf_event (rebind_subsystems)
2. CPU1 unmounts net_prio (cgroup_kill_sb), queuing root destruction work
3. A dying perf_event CSS gets queued for offline after root destruction
4. Root destruction waits for offline completion, but offline work is
   blocked behind root destruction in cgroup_destroy_wq (max_active=1)

Solution:
Split cgroup_destroy_wq into three dedicated workqueues:
cgroup_offline_wq – Handles CSS offline operations
cgroup_release_wq – Manages resource release
cgroup_free_wq – Performs final memory deallocation

This separation eliminates blocking in the CSS free path while waiting for
offline operations to complete.

[1] https://github.com/linux-test-project/ltp/blob/master/runtest/controllers
Fixes: 334c3679ec ("cgroup: reimplement rebind_subsystems() using cgroup_apply_control() and friends")
Reported-by: Gao Yingjie <gaoyingjie@uniontech.com>
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Suggested-by: Teju Heo <tj@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-02 13:34:30 +02:00
..
bpf bpf: fix potential error return 2025-01-09 13:23:36 +01:00
cgroup cgroup: split cgroup_destroy_wq into 3 workqueues 2025-10-02 13:34:30 +02:00
configs
debug kdb: Use the passed prompt in kdb_position_cursor() 2024-08-19 05:33:40 +02:00
dma dma: fix call order in dmam_free_coherent 2024-08-19 05:33:41 +02:00
events perf/core: Prevent VMA split of buffer mappings 2025-08-28 16:21:23 +02:00
gcov gcov: add support for GCC 14 2024-07-05 09:08:24 +02:00
irq genirq: Provide new interfaces for affinity hints 2025-10-02 13:34:29 +02:00
livepatch livepatch: fix race between fork and KLP transition 2022-10-26 13:22:18 +02:00
locking locking/lockdep: Decrease nr_unused_locks if lock unused in zap_class() 2025-05-02 07:39:15 +02:00
power PM: sleep: console: Fix the black screen issue 2025-08-28 16:21:25 +02:00
printk printk: Fix signed integer overflow when defining LOG_BUF_LEN_MAX 2025-03-13 12:43:02 +01:00
rcu rcu: Protect ->defer_qs_iw_pending from data race 2025-08-28 16:21:26 +02:00
sched cpufreq/sched: Explicitly synchronize limits_changed flag handling 2025-09-09 18:44:00 +02:00
time posix-cpu-timers: fix race between handle_posix_cpu_timers() and posix_cpu_timer_del() 2025-06-27 11:02:57 +01:00
trace ftrace: Fix potential warning in trace_printk_seq during ftrace_dump 2025-09-04 14:05:53 +02:00
.gitignore kbuild: update config_data.gz only when the content of .config is changed 2021-05-11 14:04:16 +02:00
acct.c acct: perform last write from workqueue 2025-03-13 12:43:26 +01:00
async.c treewide: Remove uninitialized_var() usage 2023-06-09 10:29:01 +02:00
audit.c audit: Send netlink ACK before setting connection in auditd_set 2024-02-23 08:24:54 +01:00
audit.h audit: log AUDIT_TIME_* records only from rules 2022-04-15 14:18:04 +02:00
audit_fsnotify.c audit: fix potential double free on error path from fsnotify_add_inode_mark 2022-09-05 10:27:38 +02:00
audit_tree.c audit: move put_tree() to avoid trim_trees refcount underflow and UAF 2021-09-03 10:08:16 +02:00
audit_watch.c audit: don't WARN_ON_ONCE(!current->mm) in audit_exe_compare() 2023-11-28 16:50:18 +00:00
auditfilter.c
auditsc.c audit: fix possible soft lockup in __audit_inode_child() 2023-09-23 10:59:46 +02:00
backtracetest.c treewide: Replace DECLARE_TASKLET() with DECLARE_TASKLET_OLD() 2023-04-20 12:07:32 +02:00
bounds.c bounds: Use the right number of bits for power-of-two CONFIG_NR_CPUS 2024-05-02 16:18:37 +02:00
capability.c
compat.c sched_getaffinity: don't assume 'cpumask_size()' is fully initialized 2023-04-05 11:16:42 +02:00
configs.c
context_tracking.c
cpu.c hrtimers: Handle CPU state correctly on hotplug 2025-02-01 18:18:51 +01:00
cpu_pm.c
crash_core.c
crash_dump.c
cred.c cred: switch to using atomic_long_t 2023-12-20 15:41:18 +01:00
delayacct.c
dma.c
exec_domain.c
exit.c perf: Fix sample vs do_exit() 2025-06-27 11:02:58 +01:00
extable.c kernel/extable.c: use address-of operator on section symbols 2023-06-09 10:29:01 +02:00
fail_function.c kernel/fail_function: fix memory leak with using debugfs_lookup() 2023-03-11 16:44:15 +01:00
fork.c mm: drop the assumption that VM_SHARED always implies writable 2025-08-28 16:21:36 +02:00
freezer.c
futex.c treewide: Remove uninitialized_var() usage 2023-06-09 10:29:01 +02:00
gen_kheaders.sh kheaders: Ignore silly-rename files 2025-02-01 18:18:51 +01:00
groups.c
hung_task.c
iomem.c
irq_work.c
jump_label.c
kallsyms.c
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c
kexec.c
kexec_core.c kexec: fix a memory leak in crash_shrink_memory() 2023-07-27 08:37:10 +02:00
kexec_elf.c kexec: initialize ELF lowest address to ULONG_MAX 2025-04-10 14:29:41 +02:00
kexec_file.c kexec: support purgatories with .text.hot sections 2023-06-21 15:44:10 +02:00
kexec_internal.h
kheaders.c kheaders: Use array declaration instead of char 2023-05-17 11:35:33 +02:00
kmod.c
kprobes.c kprobes: Fix possible use-after-free issue on kprobe registration 2024-05-02 16:18:30 +02:00
ksysfs.c
kthread.c kthread: fix task state in kthread worker if being frozen 2024-11-08 16:20:30 +01:00
latencytop.c
Makefile kbuild: update config_data.gz only when the content of .config is changed 2021-05-11 14:04:16 +02:00
module-internal.h
module.c modules: only allow symbol_get of EXPORT_SYMBOL_GPL modules 2023-09-23 10:59:36 +02:00
module_signature.c module: harden ELF info handling 2021-04-07 14:47:38 +02:00
module_signing.c module: harden ELF info handling 2021-04-07 14:47:38 +02:00
notifier.c
nsproxy.c
padata.c padata: fix sysfs store callback check 2025-03-13 12:42:56 +01:00
panic.c panic: Flush kernel log buffer at the end 2024-04-13 12:51:37 +02:00
params.c module: ensure that kobject_put() is safe for module type kobjects 2025-06-04 14:32:27 +02:00
pid.c
pid_namespace.c memcg: enable accounting for pids in nested pid namespaces 2021-09-22 12:26:37 +02:00
profile.c profiling: fix shift too large makes kernel panic 2022-08-25 11:18:02 +02:00
ptrace.c ptrace: Reimplement PTRACE_KILL by always sending SIGKILL 2022-06-14 18:11:24 +02:00
range.c
reboot.c kernel/reboot: emergency_restart: Set correct system_state 2023-11-28 16:50:19 +00:00
relay.c relayfs: fix out-of-bounds access in relay_file_read 2023-05-17 11:35:58 +02:00
resource.c resource: fix region_intersects() vs add_memory_driver_managed() 2024-11-08 16:20:46 +01:00
rseq.c
seccomp.c seccomp: Invalidate seccomp mode to catch death failures 2022-02-16 12:52:53 +01:00
signal.c signal: Replace BUG_ON()s 2024-11-08 16:20:38 +01:00
smp.c smp: Add missing destroy_work_on_stack() call in smp_call_on_cpu() 2024-09-12 11:03:54 +02:00
smpboot.c
smpboot.h
softirq.c tasklet: Introduce new initialization API 2025-03-13 12:43:04 +01:00
stackleak.c
stacktrace.c
stop_machine.c
sys.c getrusage: use sig->stats_lock rather than lock_task_sighand() 2024-03-15 10:48:19 -04:00
sys_ni.c kernel/sys_ni: add compat entry for fadvise64_64 2022-09-05 10:27:38 +02:00
sysctl-test.c
sysctl.c sched/rt: Disallow writing invalid values to sched_rt_period_us 2024-03-01 13:13:33 +01:00
sysctl_binary.c
task_work.c
taskstats.c
test_kprobes.c
torture.c
tracepoint.c tracepoint: Add tracepoint_probe_register_may_exist() for BPF tracing 2021-07-14 16:53:08 +02:00
tsacct.c taskstats: Cleanup the use of task->exit_code 2022-02-23 11:59:57 +01:00
ucount.c
uid16.c
uid16.h
umh.c
up.c smp: Fix smp_call_function_single_async prototype 2021-05-14 09:44:33 +02:00
user-return-notifier.c
user.c
user_namespace.c
utsname.c
utsname_sysctl.c
watchdog.c watchdog: export lockup_detector_reconfigure 2022-08-25 11:18:37 +02:00
watchdog_hld.c watchdog/perf: properly initialize the turbo mode timestamp and rearm counter 2024-08-19 05:33:39 +02:00
workqueue.c workqueue: Override implicit ordered attribute in workqueue_apply_unbound_cpumask() 2023-10-25 11:53:18 +02:00
workqueue_internal.h