x86/nmi: Remove irq_work from the long duration NMI handler
[ Upstream commit
248ed51048c40d36728e70914e38bffd7821da57 ]
First, printk() is NMI-context safe now since the safe printk() has been
implemented and it already has an irq_work to make NMI-context safe.
Second, this NMI irq_work actually does not work if a NMI handler causes
panic by watchdog timeout. It has no chance to run in such case, while
the safe printk() will flush its per-cpu buffers before panicking.
While at it, repurpose the irq_work callback into a function which
concentrates the NMI duration checking and makes the code easier to
follow.
[ bp: Massage. ]
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200111125427.15662-1-changbin.du@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>