Mark an emergency section within print_usage_bug(), where
lockdep bugs are printed. 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.
Signed-off-by: John Ogness <john.ogness@xxxxxxxxxxxxx>
---
kernel/locking/lockdep.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index e85b5ad3e206..00465373d358 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -56,6 +56,7 @@
#include <linux/kprobes.h>
#include <linux/lockdep.h>
#include <linux/context_tracking.h>
+#include <linux/console.h>
#include <asm/sections.h>
@@ -3970,6 +3971,8 @@ print_usage_bug(struct task_struct *curr, struct held_lock *this,
if (!debug_locks_off() || debug_locks_silent)
return;
+ nbcon_cpu_emergency_enter();
+
pr_warn("\n");
pr_warn("================================\n");
pr_warn("WARNING: inconsistent lock state\n");
@@ -3998,6 +4001,8 @@ print_usage_bug(struct task_struct *curr, struct held_lock *this,
pr_warn("\nstack backtrace:\n");
dump_stack();
+
+ nbcon_cpu_emergency_exit();
}
/*