| From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> |
| Date: Thu, 19 May 2016 17:45:27 +0200 |
| Subject: [PATCH] kernel/printk: Don't try to print from IRQ/NMI region |
| |
| On -RT we try to acquire sleeping locks which might lead to warnings |
| from lockdep or a warn_on() from spin_try_lock() (which is a rtmutex on |
| RT). |
| We don't print in general from a IRQ off region so we should not try |
| this via console_unblank() / bust_spinlocks() as well. |
| |
| Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> |
| --- |
| kernel/printk/printk.c | 10 ++++++++++ |
| 1 file changed, 10 insertions(+) |
| |
| --- a/kernel/printk/printk.c |
| +++ b/kernel/printk/printk.c |
| @@ -1630,6 +1630,11 @@ static void call_console_drivers(const c |
| if (!console_drivers) |
| return; |
| |
| + if (IS_ENABLED(CONFIG_PREEMPT_RT_BASE)) { |
| + if (in_irq() || in_nmi()) |
| + return; |
| + } |
| + |
| migrate_disable(); |
| for_each_console(con) { |
| if (exclusive_console && con != exclusive_console) |
| @@ -2357,6 +2362,11 @@ void console_unblank(void) |
| { |
| struct console *c; |
| |
| + if (IS_ENABLED(CONFIG_PREEMPT_RT_BASE)) { |
| + if (in_irq() || in_nmi()) |
| + return; |
| + } |
| + |
| /* |
| * console_unblank can no longer be called in interrupt context unless |
| * oops_in_progress is set to 1.. |
