diff options
| author | Marcos Paulo de Souza <mpdesouza@suse.com> | 2025-12-08 11:06:16 -0300 |
|---|---|---|
| committer | Petr Mladek <pmladek@suse.com> | 2025-12-15 15:10:33 +0100 |
| commit | bdfcca65e7a681f7511a5c15501a01dd855f6d23 (patch) | |
| tree | ff289adf7fcd68f79d713671d4fa1185b63a47ff /kernel | |
| parent | 4d38b88fd17e9989429e65420bf3c33ca53b2085 (diff) | |
printk: nbcon: Check for device_{lock,unlock} callbacks
These callbacks are necessary to synchronize ->write_thread callback
against other operations using the same device.
Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Link: https://patch.msgid.link/20251208-nbcon-device-cb-fix-v2-1-36be8d195123@suse.com
Signed-off-by: Petr Mladek <pmladek@suse.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/printk/nbcon.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/kernel/printk/nbcon.c b/kernel/printk/nbcon.c index 3fa403f9831f..1dfc4a6a44bf 100644 --- a/kernel/printk/nbcon.c +++ b/kernel/printk/nbcon.c @@ -1760,9 +1760,12 @@ bool nbcon_alloc(struct console *con) /* Synchronize the kthread start. */ lockdep_assert_console_list_lock_held(); - /* The write_thread() callback is mandatory. */ - if (WARN_ON(!con->write_thread)) + /* Check for mandatory nbcon callbacks. */ + if (WARN_ON(!con->write_thread || + !con->device_lock || + !con->device_unlock)) { return false; + } rcuwait_init(&con->rcuwait); init_irq_work(&con->irq_work, nbcon_irq_work); |