tree 07d32005434adb3794d8fdf5948b3fdc0d3198f5
parent 467926e4ac904feaf35f4ce5a5939d8ae07d5ba7
author Thomas Gleixner <tglx@linutronix.de> 1587999357 +0200
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1590593853 +0200

x86/apic: Move TSC deadline timer debug printk

[ Upstream commit c84cb3735fd53c91101ccdb191f2e3331a9262cb ]

Leon reported that the printk_once() in __setup_APIC_LVTT() triggers a
lockdep splat due to a lock order violation between hrtimer_base::lock and
console_sem, when the 'once' condition is reset via
/sys/kernel/debug/clear_warn_once after boot.

The initial printk cannot trigger this because that happens during boot
when the local APIC timer is set up on the boot CPU.

Prevent it by moving the printk to a place which is guaranteed to be only
called once during boot.

Mark the deadline timer check related functions and data __init while at
it.

Reported-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/87y2qhoshi.fsf@nanos.tec.linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>