On Thu, 22 Oct 2020 12:30:28 +0200
Peter Zijlstra <pet...@infradead.org> wrote:
> Subject: lockdep: Fix preemption WARN for spurious IRQ-enable
> From: Peter Zijlstra <pet...@infradead.org>
> Date: Thu Oct 22 12:23:02 CEST 2020
>
> It is valid (albeit uncommon) to call local_irq_enable() without first
> having called local_irq_disable(). In this case we enter
> lockdep_hardirqs_on*() with IRQs enabled and trip a preemption warning
> for using __this_cpu_read().
>
> Use this_cpu_read() instead to avoid the warning.
I was wondering why you were using __this_cpu_read() in the first place.
Reviewed-by: Steven Rostedt (VMware) <rost...@goodmis.org>
-- Steve
>
> Fixes: 4d004099a6 ("lockdep: Fix lockdep recursion")
> Reported-by: syzbot+53f8ce8bbc07924b6...@syzkaller.appspotmail.com
> Reported-by: kernel test robot <l...@intel.com>
> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
