linux-stable/kernel/printk
Petr Mladek d3ff380d47 printk: Properly deal with nbcon consoles on seq init
If a non-boot console is registering and boot consoles exist,
the consoles are flushed before being unregistered. This allows
the non-boot console to continue where the boot console left
off.

If for whatever reason flushing fails, the lowest seq found from
any of the enabled boot consoles is used. Until now con->seq was
checked. However, if it is an nbcon boot console, the function
nbcon_seq_read() must be used to read seq because con->seq is
not updated for nbcon consoles.

Check if it is an nbcon boot console and if so call
nbcon_seq_read() to read seq.

Also, avoid usage of con->seq as temporary storage of the
starting record. Instead, rename console_init_seq() to
get_init_console_seq() and just return the value. For nbcon
consoles set the sequence via nbcon_seq_force(), for legacy
consoles set con->seq.

The cleaned design should make sure that the value stays and is
set before the console is added to the console list. It also
unifies the sequence number initialization for legacy and nbcon
consoles.

Reviewed-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20240820063001.36405-4-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-08-21 14:56:22 +02:00
..
braille.c printk: Replace strncmp() with str_has_prefix() 2019-08-16 09:54:08 +02:00
braille.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
console_cmdline.h printk: Add match_devname_and_update_preferred_console() 2024-07-04 15:41:44 +02:00
index.c kernel/printk/index.c: fix memory leak with using debugfs_lookup() 2023-02-03 10:42:02 +01:00
internal.h printk: nbcon: Consolidate alloc() and init() 2024-08-21 14:56:22 +02:00
Makefile Revert "printk: Save console options for add_preferred_console_match()" 2024-06-25 07:58:10 +02:00
nbcon.c printk: Properly deal with nbcon consoles on seq init 2024-08-21 14:56:22 +02:00
printk_ringbuffer.c printk: ringbuffer: Skip non-finalized records in panic 2024-02-07 17:23:18 +01:00
printk_ringbuffer.h printk: Wait for all reserved records with pr_flush() 2024-02-07 17:23:18 +01:00
printk_safe.c printk: Consolidate console deferred printing 2023-07-20 13:06:22 +02:00
printk.c printk: Properly deal with nbcon consoles on seq init 2024-08-21 14:56:22 +02:00
sysctl.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00