[PATCH printk v5 27/30] panic: Mark emergency section in warn

John Ogness
2024-05-02T21:38:56Z

From: Thomas Gleixner <tglx@linutronix.de>

Mark the full contents of __warn() as an emergency section. 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.

Co-developed-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Thomas Gleixner (Intel) <tglx@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
---
kernel/panic.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/kernel/panic.c b/kernel/panic.c
index de8115c829cf..ee03193f9495 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -667,6 +667,8 @@ struct warn_args {
void __warn(const char *file, int line, void *caller, unsigned taint,
struct pt_regs *regs, struct warn_args *args)
{
+ nbcon_cpu_emergency_enter();
+
disable_trace_on_warning();

if (file)
@@ -697,6 +699,8 @@ void __warn(const char *file, int line, void *caller, unsigned taint,

/* Just a warning, don't kill lockdep. */
add_taint(taint, LOCKDEP_STILL_OK);
+
+ nbcon_cpu_emergency_exit();
}

#ifdef CONFIG_BUG
--
2.39.2