From 7c89ab27e0ed2ad5af47ddd8275cf32c681b64d1 Mon Sep 17 00:00:00 2001 Message-Id: <7c89ab27e0ed2ad5af47ddd8275cf32c681b64d1.1601675152.git.zanussi@kernel.org> In-Reply-To: <5b5a156f9808b1acf1205606e03da117214549ea.1601675151.git.zanussi@kernel.org> References: <5b5a156f9808b1acf1205606e03da117214549ea.1601675151.git.zanussi@kernel.org> From: Sebastian Andrzej Siewior Date: Thu, 19 May 2016 17:45:27 +0200 Subject: [PATCH 207/333] kernel/printk: Don't try to print from IRQ/NMI region Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.148-rt64.tar.xz 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 --- kernel/printk/printk.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 1eb212298f95..c5fbc51e61ed 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -1817,6 +1817,11 @@ static void call_console_drivers(const char *ext_text, size_t ext_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) @@ -2583,6 +2588,11 @@ 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.. -- 2.17.1