From 79fb37c4db667be32434a7301d25ec7e0d311cbf Mon Sep 17 00:00:00 2001 From: John Ogness Date: Mon, 23 Oct 2023 17:43:48 +0000 Subject: [PATCH 142/184] atomic print in printk context sometimes Signed-off-by: Sebastian Andrzej Siewior --- kernel/printk/printk.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 3d245e7527a1..b9f2072c1f31 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -2361,6 +2361,32 @@ asmlinkage int vprintk_emit(int facility, int level, printed_len = vprintk_store(facility, level, dev_info, fmt, args); + /* + * There are 3 situations where nbcon atomic printing should happen in + * the printk() caller context: + * + * 1. When booting, before the printing threads have been started. + * + * 2. During shutdown, since the printing threads may not get a + * chance to print the final messages. + * + * 3. When this CPU is in panic. + * + * Note that if boot consoles are registered (have_boot_console), the + * console_lock/console_unlock dance must be relied upon instead + * because nbcon consoles cannot print simultaneously with boot + * consoles. + */ + if (!have_boot_console) { + if (!printk_threads_enabled || + (system_state > SYSTEM_RUNNING) || + this_cpu_in_panic()) { + preempt_disable(); + nbcon_atomic_flush_all(); + preempt_enable(); + } + } + nbcon_wake_threads(); /* If called from the scheduler, we can not call up(). */ -- 2.34.1