Petr Mladek d73b916bcc printk: Disable passing console lock owner completely during panic() ... [ Upstream commit d04d5882cd ] The commit d51507098f ("printk: disable optimistic spin during panic") added checks to avoid becoming a console waiter if a panic is in progress. However, the transition to panic can occur while there is already a waiter. The current owner should not pass the lock to the waiter because it might get stopped or blocked anytime. Also the panic context might pass the console lock owner to an already stopped waiter by mistake. It might happen when console_flush_on_panic() ignores the current lock owner, for example: CPU0 CPU1 ---- ---- console_lock_spinning_enable() console_trylock_spinning() [CPU1 now console waiter] NMI: panic() panic_other_cpus_shutdown() [stopped as console waiter] console_flush_on_panic() console_lock_spinning_enable() [print 1 record] console_lock_spinning_disable_and_check() [handover to stopped CPU1] This results in panic() not flushing the panic messages. Fix these problems by disabling all spinning operations completely during panic(). Another advantage is that it prevents possible deadlocks caused by "console_owner_lock". The panic() context does not need to take it any longer. The lockless checks are safe because the functions become NOPs when they see the panic in progress. All operations manipulating the state are still synchronized by the lock even when non-panic CPUs would notice the panic synchronously. The current owner might stay spinning. But non-panic() CPUs would get stopped anyway and the panic context will never start spinning. Fixes: dbdda842fe ("printk: Add console owner and waiter logic to load balance console writes") Signed-off-by: John Ogness <john.ogness@linutronix.de> Link: https://lore.kernel.org/r/20240207134103.1357162-12-john.ogness@linutronix.de Signed-off-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>		2024-03-26 18:20:34 -04:00
..
bpf	cpumap: Zero-initialise xdp_rxq_info struct before running XDP program	2024-03-15 10:48:15 -04:00
cgroup	cgroup_freezer: cgroup_freezing: Check if not frozen	2023-12-13 18:39:19 +01:00
configs	Kbuild: add Rust support	2022-09-28 09:02:20 +02:00
debug	kdb: Fix a potential buffer overflow in kdb_local()	2024-01-25 15:27:51 -08:00
dma	dma-mapping: clear dev->dma_mem to NULL after freeing it	2024-01-25 15:27:28 -08:00
entry	entry/rcu: Check TIF_RESCHED _after_ delayed RCU wake-up	2023-03-30 12:49:13 +02:00
events	perf: Fix the nr_addr_filters fix	2024-02-05 20:13:00 +00:00
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 checksum field	2022-12-31 13:33:11 +01:00
irq	genirq/affinity: Move group_cpus_evenly() into lib/	2024-01-10 17:10:33 +01:00
kcsan	kcsan: Don't expect 64 bits atomic builtins from 32 bits architectures	2023-07-19 16:21:37 +02:00
livepatch	livepatch: Fix missing newline character in klp_resolve_symbols()	2023-11-20 11:52:10 +01:00
locking	lockdep: Fix block chain corruption	2023-12-03 07:32:09 +01:00
module	kallsyms: Make module_kallsyms_on_each_symbol generally available	2024-01-05 15:18:40 +01:00
power	PM: hibernate: Enforce ordering during image compression/decompression	2024-01-31 16:16:58 -08:00
printk	printk: Disable passing console lock owner completely during panic()	2024-03-26 18:20:34 -04:00
rcu	rcu/exp: Handle RCU expedited grace period kworker allocation failure	2024-03-26 18:20:28 -04:00
sched	sched/fair: Take the scheduling domain into account in select_idle_core()	2024-03-26 18:20:30 -04:00
time	timekeeping: Fix cross-timestamp interpolation for non-x86	2024-03-26 18:20:29 -04:00
trace	bpf: Remove trace_printk_lock	2024-02-23 09:12:51 +01:00
.gitignore
acct.c	acct: fix potential integer overflow in encode_comp_t()	2022-12-31 13:32:58 +01:00
async.c	async: Introduce async_schedule_dev_nocall()	2024-01-31 16:17:00 -08:00
audit.c	audit: Send netlink ACK before setting connection in auditd_set	2024-02-05 20:12:47 +00:00
audit.h	audit: remove selinux_audit_rule_update() declaration	2022-09-07 11:30:15 -04:00
audit_fsnotify.c	audit: fix potential double free on error path from fsnotify_add_inode_mark	2022-08-22 18:50:06 -04:00
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
auditfilter.c
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	mm: multi-gen LRU: minimal implementation	2022-09-26 19:46:09 -07:00
capability.c
cfi.c	cfi: Switch to -fsanitize=kcfi	2022-09-26 10:13:13 -07:00
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.c	cpu/SMT: Make SMT control more robust against enumeration failures	2024-01-10 17:10:26 +01:00
cpu_pm.c
crash_core.c	vmcoreinfo: add kallsyms_num_syms symbol	2022-08-28 14:02:44 -07:00
crash_dump.c
cred.c	cred: switch to using atomic_long_t	2023-12-20 17:00:20 +01:00
delayacct.c	delayacct: support re-entrance detection of thrashing accounting	2022-09-26 19:46:07 -07:00
dma.c
exec_domain.c
exit.c	exit: Detect and fix irq disabled state in oops	2023-03-10 09:33:45 +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	kernel/fork: beware of __put_task_struct() calling context	2023-09-23 11:11:00 +02:00
freezer.c	freezer,sched: Rewrite core freezer logic	2022-09-07 21:53:50 +02:00
gen_kheaders.sh	kbuild: build init/built-in.a just once	2022-09-29 04:40:15 +09:00
groups.c	security: Add LSM hook to setgroups() syscall	2022-07-15 18:21:49 +00:00
hung_task.c	sched: Fix more TASK_state comparisons	2022-09-30 16:50:39 +02:00
iomem.c
irq_work.c
jump_label.c
kallsyms.c	kallsyms: Add helper kallsyms_on_each_match_symbol()	2023-10-25 12:03:16 +02:00
kallsyms_internal.h	kallsyms: Reduce the memory occupied by kallsyms_seqs_of_names[]	2023-10-25 12:03:16 +02:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c	kcov: kmsan: unpoison area->list in kcov_remote_area_put()	2022-10-03 14:03:23 -07:00
kexec.c	kernel: kexec: copy user-array safely	2023-11-28 17:06:57 +00:00
kexec_core.c	kexec: fix a memory leak in crash_shrink_memory()	2023-07-19 16:21:08 +02:00
kexec_elf.c
kexec_file.c	kexec: support purgatories with .text.hot sections	2023-06-21 16:00:55 +02:00
kexec_internal.h	panic, kexec: make __crash_kexec() NMI safe	2022-09-11 21:55:06 -07:00
kheaders.c	kheaders: Use array declaration instead of char	2023-05-11 23:03:02 +09:00
kmod.c
kprobes.c	kprobes: consistent rcu api usage for kretprobe holder	2023-12-13 18:39:17 +01:00
ksysfs.c	kexec: turn all kexec_mutex acquisitions into trylocks	2022-09-11 21:55:06 -07:00
kthread.c	signal: break out of wait loops on kthread_stop()	2022-10-09 16:01:59 -07:00
latencytop.c	latencytop: use the last element of latency_record of system	2022-09-11 21:55:12 -07:00
Makefile	cfi: Fix CFI failure with KASAN	2022-12-31 13:33:08 +01:00
module_signature.c
notifier.c
nsproxy.c	Revert "fs/exec: allow to unshare a time namespace on vfork+exec"	2022-09-13 10:38:43 -07:00
padata.c	crypto: pcrypt - Fix hungtask for PADATA_RESET	2023-11-28 17:06:58 +00:00
panic.c	panic: Reenable preemption in WARN slowpath	2023-09-23 11:11:09 +02:00
params.c
pid.c
pid_namespace.c	rcu-tasks: Fix synchronize_rcu_tasks() VS zap_pid_ns_processes()	2023-03-10 09:32:52 +01:00
profile.c	kernel/profile.c: simplify duplicated code in profile_setup()	2022-09-11 21:55:12 -07:00
ptrace.c	freezer,sched: Rewrite core freezer logic	2022-09-07 21:53:50 +02:00
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.c	PCI: Allow drivers to request exclusive config regions	2023-09-13 09:42:46 +02:00
resource_kunit.c
rseq.c	rseq: Use pr_warn_once() when deprecated/unknown ABI flags are encountered	2022-11-14 09:58:32 +01:00
scftorture.c	scftorture: Forgive memory-allocation failure if KASAN	2023-09-23 11:11:00 +02:00
scs.c
seccomp.c
signal.c	mm: suppress mm fault logging if fatal signal already pending	2023-08-03 10:24:01 +02:00
smp.c	smp,csd: Throw an error if a CSD lock is stuck for too long	2023-11-28 17:06:55 +00:00
smpboot.c	smpboot: use atomic_try_cmpxchg in cpu_wait_death and cpu_report_death	2022-09-11 21:55:10 -07:00
smpboot.h
softirq.c
stackleak.c
stacktrace.c
static_call.c
static_call_inline.c
stop_machine.c
sys.c	getrusage: use sig->stats_lock rather than lock_task_sighand()	2024-03-15 10:48:22 -04:00
sys_ni.c	kernel/sys_ni: add compat entry for fadvise64_64	2022-08-20 15:17:45 -07:00
sysctl-test.c	kernel/sysctl-test: use SYSCTL_{ZERO/ONE_HUNDRED} instead of i_{zero/one_hundred}	2022-09-08 16:56:45 -07:00
sysctl.c	proc: proc_skip_spaces() shouldn't think it is working on C strings	2022-12-05 12:09:06 -08:00
task_work.c	task_work: use try_cmpxchg in task_work_add, task_work_cancel_match and task_work_run	2022-09-11 21:55:10 -07:00
taskstats.c	genetlink: start to validate reserved header bytes	2022-08-29 12:47:15 +01:00
torture.c	torture: Fix hang during kthread shutdown phase	2023-03-10 09:34:07 +01:00
tracepoint.c	tracepoint: Optimize the critical region of mutex_lock in tracepoint_module_coming()	2022-09-26 13:01:18 -04:00
tsacct.c
ucount.c
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-return-notifier.c
user.c
user_namespace.c	ucounts: Split rlimit and ucount values and max values	2022-10-09 16:24:05 -07:00
usermode_driver.c
utsname.c
utsname_sysctl.c	kernel/utsname_sysctl.c: Fix hostname polling	2022-10-23 12:01:01 -07:00
watch_queue.c	kernel: watch_queue: copy user-array safely	2023-11-28 17:06:57 +00:00
watchdog.c	watchdog: move softlockup_panic back to early_param	2023-11-28 17:07:09 +00:00
watchdog_hld.c	watchdog/perf: more properly prevent false positives with turbo modes	2023-07-19 16:21:08 +02:00
workqueue.c	workqueue: Provide one lock class key per work_on_cpu() callsite	2023-11-28 17:06:55 +00:00
workqueue_internal.h