Petr Mladek ab4af56ae2 printk/console: Allow to disable console output by using console="" or console=null ... commit 3cffa06aee upstream. The commit 48021f9813 ("printk: handle blank console arguments passed in.") prevented crash caused by empty console= parameter value. Unfortunately, this value is widely used on Chromebooks to disable the console output. The above commit caused performance regression because the messages were pushed on slow console even though nobody was watching it. Use ttynull driver explicitly for console="" and console=null parameters. It has been created for exactly this purpose. It causes that preferred_console is set. As a result, ttySX and ttyX are not used as a fallback. And only ttynull console gets registered by default. It still allows to register other consoles either by additional console= parameters or SPCR. It prevents regression because it worked this way even before. Also it is a sane semantic. Preventing output on all consoles should be done another way, for example, by introducing mute_console parameter. Link: https://lore.kernel.org/r/20201006025935.GA597@jagdpanzerIV.localdomain Suggested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20201111135450.11214-3-pmladek@suse.com Cc: Yi Fan <yfa@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2021-11-12 14:58:33 +01:00
..
bpf	bpf: Fix error usage of map_fd and fdget() in generic_map_update_batch()	2021-11-02 19:48:21 +01:00
cgroup	cgroup: Fix memory leak caused by missing cgroup_bpf_offline	2021-11-02 19:48:21 +01:00
configs
debug
dma	dma-debug: fix sg checks in debug_dma_map_sg()	2021-10-27 09:56:47 +02:00
entry	KVM: rseq: Update rseq when processing NOTIFY_RESUME on xfer to KVM guest	2021-10-06 15:55:49 +02:00
events	perf/core: fix userpage->time_enabled of inactive events	2021-10-17 10:43:33 +02:00
gcov
irq
kcsan
livepatch
locking
power
printk	printk/console: Allow to disable console output by using console="" or console=null	2021-11-12 14:58:33 +01:00
rcu
sched	sched/scs: Reset the shadow stack when idle_task_exit	2021-10-27 09:56:55 +02:00
time
trace	tracing: Have all levels of checks prevent recursion	2021-10-27 09:56:56 +02:00
.gitignore
acct.c
async.c
audit_fsnotify.c
audit_tree.c
audit_watch.c
audit.c
audit.h
auditfilter.c
auditsc.c	audit: fix possible null-pointer dereference in audit_filter_rules	2021-10-27 09:56:52 +02:00
backtracetest.c
bounds.c
capability.c
compat.c
configs.c
context_tracking.c
cpu_pm.c
cpu.c
crash_core.c
crash_dump.c
cred.c
delayacct.c
dma.c
exec_domain.c
exit.c
extable.c
fail_function.c
fork.c	mm/hugetlb: initialize hugetlb_usage in mm_init	2021-09-18 13:40:36 +02:00
freezer.c
futex.c
gen_kheaders.sh
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_core.c
kexec_elf.c
kexec_file.c
kexec_internal.h
kexec.c
kheaders.c
kmod.c
kprobes.c
ksysfs.c
kthread.c
latencytop.c
Makefile
module_signature.c
module_signing.c
module-internal.h
module.c
notifier.c
nsproxy.c
padata.c
panic.c
params.c
pid_namespace.c	memcg: enable accounting for pids in nested pid namespaces	2021-09-18 13:40:36 +02:00
pid.c
profile.c	profiling: fix shift-out-of-bounds bugs	2021-09-26 14:08:58 +02:00
ptrace.c
range.c
reboot.c
regset.c
relay.c
resource.c
rseq.c	KVM: rseq: Update rseq when processing NOTIFY_RESUME on xfer to KVM guest	2021-10-06 15:55:49 +02:00
scftorture.c
scs.c
seccomp.c
signal.c
smp.c
smpboot.c
smpboot.h
softirq.c
stackleak.c
stacktrace.c
static_call.c
stop_machine.c
sys_ni.c
sys.c	prctl: allow to setup brk for et_dyn executables	2021-09-26 14:08:57 +02:00
sysctl-test.c
sysctl.c
task_work.c
taskstats.c
test_kprobes.c
torture.c
tracepoint.c
tsacct.c
ucount.c
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
watchdog_hld.c
watchdog.c
workqueue_internal.h
workqueue.c