From f97960fbddd98e1b7bfba469b8510b49a62b4bc5 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 17 Nov 2016 17:31:55 +0100 Subject: kernel/printk: Block cpuhotplug callback when tasks are frozen The recent conversion of the console hotplug notifier to the state machine missed the fact, that the notifier only operated on the non frozen transitions. As a consequence the console_lock/unlock() pair is also invoked during suspend, which results in a lockdep warning. Restore the previous state by making the lock/unlock conditional on !tasks_frozen. Fixes: 90b14889d2f9 ("kernel/printk: Convert to hotplug state machine") Reported-and-tested-by: Borislav Petkov Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1611171729320.3645@nanos Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra Cc: Sebastian Andrzej Siewior --- kernel/printk/printk.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'kernel/printk') diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 4487ffcd42d5..37893da9bae8 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -2194,8 +2194,10 @@ void resume_console(void) */ static int console_cpu_notify(unsigned int cpu) { - console_lock(); - console_unlock(); + if (!cpuhp_tasks_frozen) { + console_lock(); + console_unlock(); + } return 0; } -- cgit v1.2.3