Paul E. McKenney 593889c401 srcu: Don't queue workqueue handlers to never-online CPUs ... While an srcu_struct structure is in the midst of switching from CPU-0 to all-CPUs state, it can attempt to invoke callbacks for CPUs that have never been online. Worse yet, it can attempt in invoke callbacks for CPUs that never will be online, even including imaginary CPUs not in cpu_possible_mask. This can cause hangs on s390, which is not set up to deal with workqueue handlers being scheduled on such CPUs. This commit therefore causes Tree SRCU to refrain from queueing workqueue handlers on CPUs that have not yet (and might never) come online. Because callbacks are not invoked on CPUs that have not been online, it is an error to invoke call_srcu(), synchronize_srcu(), or synchronize_srcu_expedited() on a CPU that is not yet fully online. However, it turns out to be less code to redirect the callbacks from too-early invocations of call_srcu() than to warn about such invocations. This commit therefore also redirects callbacks queued on not-yet-fully-online CPUs to the boot CPU. Reported-by: Vasily Gorbik <gor@linux.ibm.com> Fixes: 61bbcfb505 ("srcu: Push srcu_node allocation to GP when non-preemptible") Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Tested-by: Vasily Gorbik <gor@linux.ibm.com> Tested-by: Samir <samir@linux.ibm.com> Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Boqun Feng <boqun@kernel.org>		2026-05-18 12:27:18 -07:00
..
bpf	bpf-fixes	2026-04-17 15:58:22 -07:00
cgroup	cgroup: Fixes for v7.1-rc1	2026-04-27 16:51:27 -07:00
configs	Remove WARN_ALL_UNSEEDED_RANDOM kernel config option	2026-02-23 11:18:48 -08:00
debug	kgdb: update outdated references to kgdb_wait()	2026-04-21 16:41:54 +01:00
dma	memblock: updates for 7.0-rc1	2026-04-18 11:29:14 -07:00
entry	arm64 updates for 7.1:	2026-04-14 16:48:56 -07:00
events	mm.git review status for linus..mm-stable	2026-04-15 12:59:16 -07:00
futex	futex: Prevent lockup in requeue-PI during signal/ timeout wakeup	2026-04-29 08:56:40 +02:00
gcov	Convert more 'alloc_obj' cases to default GFP_KERNEL arguments	2026-02-21 20:03:00 -08:00
irq	genirq/chip: Invoke add_interrupt_randomness() in handle_percpu_devid_irq()	2026-04-02 23:03:29 +02:00
kcsan	kcsan: test: Adjust "expect" allocation type for kmalloc_obj	2026-02-26 09:54:08 -08:00
livepatch	Convert 'alloc_obj' family to use the new default GFP_KERNEL argument	2026-02-21 17:09:51 -08:00
liveupdate	kho: fix error handling in kho_add_subtree()	2026-04-27 05:54:23 -07:00
locking	locking/mutex: Fix ww_mutex wait_list operations	2026-04-23 10:05:49 +02:00
module	module: Simplify warning on positive returns from module_init()	2026-04-04 00:04:48 +00:00
power	Merge branches 'pm-cpuidle', 'pm-opp' and 'pm-sleep'	2026-04-10 12:37:27 +02:00
printk	Merge branch 'rework/prb-fixes' into for-linus	2026-04-20 13:42:01 +02:00
rcu	srcu: Don't queue workqueue handlers to never-online CPUs	2026-05-18 12:27:18 -07:00
sched	Miscellaneous scheduler fixes:	2026-05-03 08:05:23 -07:00
time	clockevents: Add missing resets of the next_event_forced flag	2026-04-16 21:22:04 +02:00
trace	tracing/probes: Limit size of event probe to 3K	2026-04-29 16:07:38 -04:00
unwind	Convert more 'alloc_obj' cases to default GFP_KERNEL arguments	2026-02-21 20:03:00 -08:00
.gitignore	kheaders: rebuild kheaders_data.tar.xz when a file is modified within a minute	2025-06-24 20:30:37 +09:00
Kconfig.freezer	…
Kconfig.hz	…
Kconfig.kexec	liveupdate: kho: move to kernel/liveupdate	2025-11-27 14:24:33 -08:00
Kconfig.locks	…
Kconfig.preempt	sched: Further restrict the preemption modes	2026-01-08 12:43:57 +01:00
Makefile	kcov: Enable context analysis	2026-01-05 16:43:34 +01:00
acct.c	vfs-7.1-rc1.misc	2026-04-13 14:20:11 -07:00
async.c	Convert 'alloc_obj' family to use the new default GFP_KERNEL argument	2026-02-21 17:09:51 -08:00
audit.c	audit: handle unknown status requests in audit_receive_msg()	2026-03-10 15:22:43 -04:00
audit.h	audit: widen ino fields to u64	2026-03-06 14:31:26 +01:00
audit_fsnotify.c	audit: widen ino fields to u64	2026-03-06 14:31:26 +01:00
audit_tree.c	Convert 'alloc_flex' family to use the new default GFP_KERNEL argument	2026-02-21 17:09:51 -08:00
audit_watch.c	audit: widen ino fields to u64	2026-03-06 14:31:26 +01:00
auditfilter.c	audit: fix coding style issues	2026-03-05 22:16:08 -05:00
auditsc.c	audit: widen ino fields to u64	2026-03-06 14:31:26 +01:00
backtracetest.c	…
bounds.c	x86/asm: Remove ANNOTATE_DATA_SPECIAL usage	2025-12-03 16:53:19 +01:00
capability.c	…
cfi.c	cfi: Move BPF CFI types and helpers to generic code	2025-07-31 18:23:53 -07:00
compat.c	…
configs.c	…
context_tracking.c	context_tracking: Remove rcu_task_trace_heavyweight_{enter,exit}()	2026-01-01 16:39:46 +08:00
cpu.c	SPDX updates for 7.0-rc1	2026-02-17 09:46:03 -08:00
cpu_pm.c	syscore: Pass context data to callbacks	2025-11-14 10:01:52 +01:00
crash_core.c	kernel/crash: remove inclusion of crypto/sha1.h	2026-03-27 21:19:46 -07:00
crash_core_test.c	crash: add KUnit tests for crash_exclude_mem_range	2025-09-13 17:32:55 -07:00
crash_dump_dm_crypt.c	crash_dump/dm-crypt: don't print in arch-specific code	2026-04-02 23:36:24 -07:00
crash_reserve.c	kernel/crash: remove inclusion of crypto/sha1.h	2026-03-27 21:19:46 -07:00
cred.c	cred: remove unused set_security_override_from_ctx()	2026-01-06 20:52:57 -05:00
delayacct.c	delayacct: fix uapi timespec64 definition	2026-02-08 00:13:32 -08:00
dma.c	…
elfcorehdr.c	…
exec_domain.c	…
exit.c	mm.git review status for linus..mm-nonmm-stable	2026-04-16 20:11:56 -07:00
exit.h	…
extable.c	…
fail_function.c	Convert 'alloc_obj' family to use the new default GFP_KERNEL argument	2026-02-21 17:09:51 -08:00
fork.c	futex: Drop CLONE_THREAD requirement for private default hash alloc	2026-05-01 13:12:34 -07:00
freezer.c	freezer: Clarify that only cgroup1 freezer uses PM freezer	2025-10-30 20:10:27 +01:00
gen_kheaders.sh	kheaders: make it possible to override TAR	2025-08-06 10:23:36 +09:00
groups.c	treewide: Replace kmalloc with kmalloc_obj for non-scalar types	2026-02-21 01:02:28 -08:00
hung_task.c	hung_task: explicitly report I/O wait state in log output	2026-03-27 21:19:40 -07:00
iomem.c	…
irq_work.c	kernel: Use trace_call__##name() at guarded tracepoint call sites	2026-03-26 08:28:49 -04:00
jump_label.c	jump_label: use ATOMIC_INIT() for initialization of .enabled	2026-03-16 13:16:48 +01:00
kallsyms.c	mm.git review status for linus..mm-nonmm-stable	2026-02-12 12:13:01 -08:00
kallsyms_internal.h	kallsyms: Get rid of kallsyms relative base	2026-01-22 15:58:22 -07:00
kallsyms_selftest.c	Convert 'alloc_obj' family to use the new default GFP_KERNEL argument	2026-02-21 17:09:51 -08:00
kallsyms_selftest.h	…
kcmp.c	…
kcov.c	Convert 'alloc_obj' family to use the new default GFP_KERNEL argument	2026-02-21 17:09:51 -08:00
kexec.c	Convert 'alloc_obj' family to use the new default GFP_KERNEL argument	2026-02-21 17:09:51 -08:00
kexec_core.c	kernel/kexec: remove inclusion of crypto/hash.h	2026-03-27 21:19:46 -07:00
kexec_elf.c	…
kexec_file.c	kexec: derive purgatory entry from symbol	2026-01-31 16:16:07 -08:00
kexec_internal.h	kexec: enable CMA based contiguous allocation	2025-08-02 12:01:38 -07:00
kheaders.c	…
kprobes.c	kprobes: Remove unneeded warnings from __arm_kprobe_ftrace()	2026-03-13 23:15:26 +09:00
kstack_erase.c	sysctl: remove __user qualifier from stack_erasing_sysctl buffer argument	2025-11-27 15:44:53 +01:00
ksyms_common.c	…
ksysfs.c	kernel: ksysfs: initialize kernel_kobj earlier	2026-04-03 19:39:52 +02:00
kthread.c	kthread: consolidate kthread exit paths to prevent use-after-free	2026-02-26 10:45:49 +01:00
latencytop.c	…
module_signature.c	module: Give 'enum pkey_id_type' a more specific name	2026-03-24 21:42:37 +00:00
notifier.c	…
nscommon.c	nsfs: tighten permission checks for ns iteration ioctls	2026-02-27 22:00:08 +01:00
nsproxy.c	vfs-7.1-rc1.mount.v2	2026-04-14 19:59:25 -07:00
nstree.c	nstree: tighten permission checks for listing	2026-02-27 22:00:11 +01:00
padata.c	padata: Put CPU offline callback in ONLINE section to allow failure	2026-03-22 11:17:59 +09:00
panic.c	kernel/panic: mark init_taint_buf as __initdata and panic instead of warning in alloc_taint_buf()	2026-03-27 21:19:33 -07:00
params.c	module: Clean up parse_args() arguments	2026-03-18 21:43:18 +00:00
pid.c	mm.git review status for linus..mm-nonmm-stable	2026-04-16 20:11:56 -07:00
pid_namespace.c	pid_namespace: allow opening pid_for_children before init was created	2026-03-20 14:44:26 +01:00
pid_sysctl.h	…
profile.c	…
ptrace.c	clone: add CLONE_AUTOREAP	2026-03-11 23:14:02 +01:00
range.c	…
reboot.c	treewide: Replace kmalloc with kmalloc_obj for non-scalar types	2026-02-21 01:02:28 -08:00
regset.c	…
relay.c	Convert 'alloc_obj' family to use the new default GFP_KERNEL argument	2026-02-21 17:09:51 -08:00
resource.c	PCI: Align head space better	2026-03-27 10:19:08 -05:00
resource_kunit.c	Convert 'alloc_obj' family to use the new default GFP_KERNEL argument	2026-02-21 17:09:51 -08:00
rseq.c	rseq: slice ext: Ensure rseq feature size differs from original rseq size	2026-02-23 11:19:19 +01:00
scftorture.c	Convert 'alloc_obj' family to use the new default GFP_KERNEL argument	2026-02-21 17:09:51 -08:00
scs.c	scs: fix a wrong parameter in __scs_magic	2025-11-12 10:00:13 -08:00
seccomp.c	Convert 'alloc_obj' family to use the new default GFP_KERNEL argument	2026-02-21 17:09:51 -08:00
signal.c	mm.git review status for linus..mm-nonmm-stable	2026-04-16 20:11:56 -07:00
smp.c	tracing updates for v7.1:	2026-04-17 09:43:12 -07:00
smpboot.c	sched/smp: Use the SMP version of idle_thread_set_boot_cpu()	2025-06-13 08:47:20 +02:00
smpboot.h	…
softirq.c	softirq: Prepare for deferred hrtimer rearming	2026-02-27 16:40:13 +01:00
stacktrace.c	…
static_call.c	…
static_call_inline.c	Convert 'alloc_obj' family to use the new default GFP_KERNEL argument	2026-02-21 17:09:51 -08:00
stop_machine.c	sched/core: Fix migrate_swap() vs. hotplug	2025-07-01 15:02:03 +02:00
sys.c	prctl: cfi: change the branch landing pad prctl()s to be more descriptive	2026-04-04 18:40:58 -06:00
sys_ni.c	rseq: Implement sys_rseq_slice_yield()	2026-01-22 11:11:17 +01:00
sysctl-test.c	…
sysctl.c	sysctl: fix uninitialized variable in proc_do_large_bitmap	2026-03-26 09:32:19 +01:00
task_work.c	task_work: Fix NMI race condition	2025-10-29 10:29:54 +01:00
taskstats.c	taskstats: set version in TGID exit notifications	2026-04-15 02:15:02 -07:00
torture.c	torture: Avoid modulo-zero error in torture_hrtimeout_ns()	2026-03-30 15:48:14 -04:00
tracepoint.c	tracepoint: balance regfunc() on func_add() failure in tracepoint_add_func()	2026-04-14 05:17:02 -04:00
tsacct.c	tsacct: skip all kernel threads	2026-01-26 19:07:13 -08:00
ucount.c	Convert 'alloc_obj' family to use the new default GFP_KERNEL argument	2026-02-21 17:09:51 -08:00
uid16.c	…
uid16.h	…
umh.c	treewide: Replace kmalloc with kmalloc_obj for non-scalar types	2026-02-21 01:02:28 -08:00
up.c	…
user-return-notifier.c	…
user.c	ns: drop custom reference count initialization for initial namespaces	2025-11-11 10:01:32 +01:00
user_namespace.c	Convert remaining multi-line kmalloc_obj/flex GFP_KERNEL uses	2026-02-22 08:26:33 -08:00
utsname.c	namespace-6.18-rc1	2025-09-29 11:20:29 -07:00
utsname_sysctl.c	…
vhost_task.c	Convert 'alloc_obj' family to use the new default GFP_KERNEL argument	2026-02-21 17:09:51 -08:00
vmcore_info.c	mm.git review status for linus..mm-nonmm-stable	2026-04-16 20:11:56 -07:00
watch_queue.c	Convert 'alloc_flex' family to use the new default GFP_KERNEL argument	2026-02-21 17:09:51 -08:00
watchdog.c	watchdog/hardlockup: improve buddy system detection timeliness	2026-03-27 21:19:47 -07:00
watchdog_buddy.c	watchdog/hardlockup: improve buddy system detection timeliness	2026-03-27 21:19:47 -07:00
watchdog_perf.c	watchdog/hardlockup: simplify perf event probe and remove per-cpu dependency	2026-02-08 00:13:35 -08:00
workqueue.c	workqueue: Changes for v7.1	2026-04-15 10:32:08 -07:00
workqueue_internal.h	workqueue: Show in-flight work item duration in stall diagnostics	2026-03-05 07:27:48 -10:00