Re: [PATCH] lockdep: Do not record irq state in debug_check_no_locks_freed()

From: Peter Zijlstra
Date: Wed Apr 04 2018 - 12:23:18 EST


On Wed, Apr 04, 2018 at 12:19:04PM -0400, Steven Rostedt wrote:
> From: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
>
> While debugging where things were going wrong with mapping
> enabling/disabling interrupts with the lockdep state and actual real
> enabling and disabling interrupts, I had to silent the irq
> disabling/enabling in debug_check_no_locks_freed() because it was
> always showing up as it was called before the splat was.
>
> Use raw_local_irq_save/restore() for debug_check_no_locks_freed() as it
> hides useful information about where interrupts were used incorrectly
> last.
>
> Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
> ---
> diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
> index 89b5f83f1969..8c145dc1315b 100644
> --- a/kernel/locking/lockdep.c
> +++ b/kernel/locking/lockdep.c
> @@ -4407,7 +4407,7 @@ void debug_check_no_locks_freed(const void *mem_from, unsigned long mem_len)
> if (unlikely(!debug_locks))
> return;
>
> - local_irq_save(flags);
> + raw_local_irq_save(flags);
> for (i = 0; i < curr->lockdep_depth; i++) {
> hlock = curr->held_locks + i;
>
> @@ -4418,7 +4418,7 @@ void debug_check_no_locks_freed(const void *mem_from, unsigned long mem_len)
> print_freed_lock_bug(curr, mem_from, mem_from + mem_len, hlock);
> break;
> }
> - local_irq_restore(flags);
> + raw_local_irq_restore(flags);
> }
> EXPORT_SYMBOL_GPL(debug_check_no_locks_freed);

Makes sense, could you convert all of them just to make sure there
aren't any left?