panic: Mark emergency section in oops

Mark an emergency section beginning with oops_enter() until the
end of oops_exit(). In this section, every printk() call will
attempt to directly flush to the consoles using the EMERGENCY
priority.

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
flushed the oops messages.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240820063001.36405-34-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>

diff --git a/kernel/panic.c b/kernel/panic.c
index 1a10b6e2a8550377276400216ffb587265462966..753d12f4dc8f4efa3726442d2da1515edf02e75d 100644 (file)
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -685,6 +685,7 @@ 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();
@@ -707,6 +708,7 @@ void oops_exit(void)
 {
        do_oops_enter_exit();
        print_oops_end_marker();
+       nbcon_cpu_emergency_exit();
        kmsg_dump(KMSG_DUMP_OOPS);
 }