From: John Ogness Date: Tue, 19 Sep 2023 17:07:34 +0000 Subject: [PATCH 27/46] panic: Mark emergency section in oops Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.9/older/patches-6.9-rt5.tar.xz Mark an emergency section beginning with oops_enter() until the end of oops_exit(). In this section, the CPU will not perform console output for the printk() calls. Instead, a flushing of the console output is triggered when exiting the emergency section. The very end of oops_exit() performs a kmsg_dump(). This is not included in the emergency section because it is another flushing mechanism that should occur after the consoles have been triggered to flush. Signed-off-by: John Ogness Reviewed-by: Petr Mladek Signed-off-by: Sebastian Andrzej Siewior --- kernel/panic.c | 2 ++ 1 file changed, 2 insertions(+) --- a/kernel/panic.c +++ b/kernel/panic.c @@ -638,6 +638,7 @@ bool oops_may_print(void) */ void oops_enter(void) { + nbcon_cpu_emergency_enter(); tracing_off(); /* can't trust the integrity of the kernel anymore: */ debug_locks_off(); @@ -660,6 +661,7 @@ void oops_exit(void) { do_oops_enter_exit(); print_oops_end_marker(); + nbcon_cpu_emergency_exit(); kmsg_dump(KMSG_DUMP_OOPS); }