John Ogness 2830eec14a printk: introduce printk_get_next_message() and printk_message ... Code for performing the console output is intermixed with code that is formatting the output for that console. Introduce a new helper function printk_get_next_message() to handle the reading and formatting of the printk text. The helper does not require any locking so that in the future it can be used for other printing contexts as well. This also introduces a new struct printk_message to wrap the struct printk_buffers, adding metadata about its contents. This allows users of printk_get_next_message() to receive all relevant information about the message that was read and formatted. Why is struct printk_message a wrapper struct? It is intentional that a wrapper struct is introduced instead of adding the metadata directly to struct printk_buffers. The upcoming atomic consoles support multiple printing contexts per CPU. This means that while a CPU is formatting a message, it can be interrupted and the interrupting context may also format a (possibly different) message. Since the printk buffers are rather large, there will only be one struct printk_buffers per CPU and it must be shared by the possible contexts of that CPU. If the metadata was part of struct printk_buffers, interrupting contexts would clobber the metadata being prepared by the interrupted context. This could be handled by robustifying the message formatting functions to cope with metadata unexpectedly changing. However, this would require significant amounts of extra data copying, also adding significant complexity to the code. Instead, the metadata can live on the stack of the formatting context and the message formatting functions do not need to be concerned about the metadata changing underneath them. Note that the message formatting functions can handle unexpected text buffer changes. So it is perfectly OK if a shared text buffer is clobbered by an interrupting context. The atomic console implementation will recognize the interruption and avoid printing the (probably garbage) text buffer. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20230109100800.1085541-6-john.ogness@linutronix.de		2023-01-11 15:35:11 +01:00
..
bpf	bpf: Do not copy spin lock field from user in bpf_selem_alloc	2022-11-21 11:45:37 -08:00
cgroup	memcg: Fix possible use-after-free in memcg_write_event_control()	2022-12-08 10:40:58 -08:00
configs	Kbuild: add Rust support	2022-09-28 09:02:20 +02:00
debug	kdb: use srcu console list iterator	2022-12-02 11:25:00 +01:00
dma	- Yu Zhao's Multi-Gen LRU patches are here. They've been under test in	2022-10-10 17:53:04 -07:00
entry	entry: kmsan: introduce kmsan_unpoison_entry_regs()	2022-10-03 14:03:25 -07:00
events	- Fix a use-after-free case where the perf pending task callback would	2022-12-04 12:36:23 -08:00
futex	freezer,sched: Rewrite core freezer logic	2022-09-07 21:53:50 +02:00
gcov	gcov: clang: fix the buffer overflow issue	2022-11-22 18:50:41 -08:00
irq	genirq: Provide generic_handle_domain_irq_safe().	2022-09-19 15:08:38 +02:00
kcsan	kcsan: Instrument memcpy/memset/memmove with newer Clang	2022-10-18 15:07:33 -07:00
livepatch	Livepatching changes for 6.1	2022-10-10 11:36:19 -07:00
locking	treewide: use prandom_u32_max() when possible, part 1	2022-10-11 17:42:55 -06:00
module	module: tracking: Keep a record of tainted unloaded modules only	2022-10-10 12:16:19 -07:00
power	PM: hibernate: Allow hybrid sleep to work with s2idle	2022-10-25 14:53:19 +02:00
printk	printk: introduce printk_get_next_message() and printk_message	2023-01-11 15:35:11 +01:00
rcu	printk changes for 6.2	2022-12-12 09:01:36 -08:00
sched	Revert "cpufreq: schedutil: Move max CPU capacity to sugov_policy"	2022-11-22 19:56:52 +01:00
time	treewide: use prandom_u32_max() when possible, part 1	2022-10-11 17:42:55 -06:00
trace	tracing: Free buffers when a used dynamic event is removed	2022-11-23 19:07:12 -05:00
.gitignore
acct.c	acct: use VMA iterator instead of linked list	2022-09-26 19:46:22 -07:00
async.c
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: use fsnotify group lock helpers	2022-04-25 14:37:28 +02:00
audit_watch.c	audit_init_parent(): constify path	2022-09-01 17:39:30 -04:00
audit.c	audit: use time_after to compare time	2022-08-29 19:47:03 -04:00
audit.h	audit: remove selinux_audit_rule_update() declaration	2022-09-07 11:30:15 -04:00
auditfilter.c
auditsc.c	audit/stable-6.1 PR 20221003	2022-10-04 11:05:43 -07:00
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
configs.c
context_tracking.c	MAINTAINERS: Add Paul as context tracking maintainer	2022-07-05 13:33:00 -07:00
cpu_pm.c	context_tracking: Take IRQ eqs entrypoints over RCU	2022-07-05 13:32:59 -07:00
cpu.c	Intel Trust Domain Extensions	2022-05-23 17:51:12 -07:00
crash_core.c	vmcoreinfo: add kallsyms_num_syms symbol	2022-08-28 14:02:44 -07:00
crash_dump.c
cred.c
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	- hfs and hfsplus kmap API modernization from Fabio Francesco	2022-10-12 11:00:22 -07:00
extable.c	context_tracking: Take NMI eqs entrypoints over RCU	2022-07-05 13:32:59 -07:00
fail_function.c	fail_function: fix wrong use of fei_attr_remove()	2022-09-11 21:55:11 -07:00
fork.c	execve updates for v6.2-rc1	2022-12-12 08:42:29 -08:00
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	irq_work: use kasan_record_aux_stack_noalloc() record callstack	2022-04-15 14:49:55 -07:00
jump_label.c	jump_label: make initial NOP patching the special case	2022-06-24 09:48:55 +02:00
kallsyms_internal.h	kallsyms: move declarations to internal header	2022-07-17 17:31:39 -07:00
kallsyms.c	kcfi updates for v6.1-rc1	2022-10-03 17:11:07 -07:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt	Revert "signal, x86: Delay calling signals in atomic on RT enabled kernels"	2022-03-31 10:36:55 +02:00
kcov.c	kcov: kmsan: unpoison area->list in kcov_remote_area_put()	2022-10-03 14:03:23 -07:00
kexec_core.c	kexec: replace kmap() with kmap_local_page()	2022-09-11 21:55:08 -07:00
kexec_elf.c
kexec_file.c	panic, kexec: make __crash_kexec() NMI safe	2022-09-11 21:55:06 -07:00
kexec_internal.h	panic, kexec: make __crash_kexec() NMI safe	2022-09-11 21:55:06 -07:00
kexec.c	panic, kexec: make __crash_kexec() NMI safe	2022-09-11 21:55:06 -07:00
kheaders.c
kmod.c
kprobes.c	kprobes: Skip clearing aggrprobe's post_handler in kprobe-on-ftrace case	2022-11-18 10:15:34 +09:00
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	kmsan: disable instrumentation of unsupported common kernel code	2022-10-03 14:03:20 -07:00
module_signature.c
notifier.c	notifier: Add blocking/atomic_notifier_chain_register_unique_prio()	2022-05-19 19:30:30 +02:00
nsproxy.c	fs/exec: switch timens when a task gets a new mm	2022-10-25 15:15:52 -07:00
padata.c
panic.c	kernel/panic: Drop unblank_screen call	2022-09-01 16:55:35 +02:00
params.c
pid_namespace.c	kernel: pid_namespace: use NULL instead of using plain integer as pointer	2022-04-29 14:38:00 -07:00
pid.c	gfs2: Add glockfd debugfs file	2022-06-29 13:07:16 +02:00
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: Add SYS_OFF_MODE_RESTART_PREPARE mode	2022-10-04 15:59:36 +02:00
regset.c
relay.c	relay: use kvcalloc to alloc page array in relay_alloc_page_array	2022-10-03 14:21:43 -07:00
resource_kunit.c
resource.c	resource: Introduce alloc_free_mem_region()	2022-07-21 17:19:25 -07:00
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: Fix distribution of short handler delays	2022-04-11 17:07:29 -07:00
scs.c	kasan, vmalloc: only tag normal vmalloc allocations	2022-03-24 19:06:48 -07:00
seccomp.c	seccomp: Add wait_killable semantic to seccomp user notifier	2022-05-03 14:11:58 -07:00
signal.c	Scheduler changes for v6.1:	2022-10-10 09:10:28 -07:00
smp.c	bitmap patches for v6.1-rc1	2022-10-10 12:49:34 -07:00
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	context_tracking: Take IRQ eqs entrypoints over RCU	2022-07-05 13:32:59 -07:00
stackleak.c	stackleak: add on/off stack variants	2022-05-08 01:33:09 -07:00
stacktrace.c
static_call_inline.c	static_call: Don't make __static_call_return0 static	2022-04-05 09:59:38 +02:00
static_call.c	static_call: Don't make __static_call_return0 static	2022-04-05 09:59:38 +02:00
stop_machine.c	Scheduler changes in this cycle were:	2022-05-24 11:11:13 -07:00
sys_ni.c	kernel/sys_ni: add compat entry for fadvise64_64	2022-08-20 15:17:45 -07:00
sys.c	Random number generator updates for Linux 6.1-rc1.	2022-10-10 10:41:21 -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
tracepoint.c	tracepoint: Optimize the critical region of mutex_lock in tracepoint_module_coming()	2022-09-26 13:01:18 -04:00
tsacct.c	taskstats: version 12 with thread group and exe info	2022-04-29 14:38:03 -07:00
ucount.c	ucounts: Split rlimit and ucount values and max values	2022-05-18 18:24:57 -05:00
uid16.c
uid16.h
umh.c	freezer,sched: Rewrite core freezer logic	2022-09-07 21:53:50 +02:00
up.c
user_namespace.c	ucounts: Split rlimit and ucount values and max values	2022-10-09 16:24:05 -07:00
user-return-notifier.c
user.c
usermode_driver.c	blob_to_mnt(): kern_unmount() is needed to undo kern_mount()	2022-05-19 23:25:47 -04:00
utsname_sysctl.c	kernel/utsname_sysctl.c: Fix hostname polling	2022-10-23 12:01:01 -07:00
utsname.c
watch_queue.c	This was a moderately busy cycle for documentation, but nothing all that	2022-08-02 19:24:24 -07:00
watchdog_hld.c	Revert "printk: add functions to prefer direct printing"	2022-06-23 18:41:40 +02:00
watchdog.c	powerpc updates for 6.0	2022-08-06 16:38:17 -07:00
workqueue_internal.h
workqueue.c	workqueue: Make queue_rcu_work() use call_rcu_hurry()	2022-11-30 13:17:05 -08:00