Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1441586

[PATCH RT 4/8] kernel/printk: Dont try to print from IRQ/NMI region

Show all headers | View raw

3.10.102-rt113-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

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>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/printk.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/kernel/printk.c b/kernel/printk.c
index 1b7fbc73c125..55b6871f21e2 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -1302,6 +1302,11 @@ static void call_console_drivers(int level, const char *text, size_t len)
 	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)
@@ -2236,6 +2241,11 @@ 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..
-- 
2.8.1

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH RT 0/8] Linux 3.10.102-rt113-rc1 Steven Rostedt <rostedt@goodmis.org> - 2016-07-12 19:00 +0200
  [PATCH RT 8/8] Linux 3.10.102-rt113-rc1 Steven Rostedt <rostedt@goodmis.org> - 2016-07-12 19:00 +0200
  [PATCH RT 6/8] trace: correct off by one while recording the trace-event Steven Rostedt <rostedt@goodmis.org> - 2016-07-12 19:00 +0200
  [PATCH RT 4/8] kernel/printk: Dont try to print from IRQ/NMI region Steven Rostedt <rostedt@goodmis.org> - 2016-07-12 19:00 +0200
  [PATCH RT 3/8] list_bl: fixup bogus lockdep warning Steven Rostedt <rostedt@goodmis.org> - 2016-07-12 19:00 +0200
  [PATCH RT 7/8] x86: Fix an RT MCE crash Steven Rostedt <rostedt@goodmis.org> - 2016-07-12 19:10 +0200
  [PATCH RT 1/8] kvm, rt: change async pagefault code locking for PREEMPT_RT Steven Rostedt <rostedt@goodmis.org> - 2016-07-12 19:10 +0200

csiph-web