Messages in this thread | | | Date | Thu, 25 Apr 2019 21:55:15 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH 23/28] locking/lockdep: Update irqsafe lock bitmaps |
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On Wed, Apr 24, 2019 at 06:19:29PM +0800, Yuyang Du wrote: > The bitmaps keep track of which locks are irqsafe. Update the bitmaps > when there is new irqsafe usage and when an irqsafe lock is zapped. > > Signed-off-by: Yuyang Du <duyuyang@gmail.com> > --- > kernel/locking/lockdep.c | 39 ++++++++++++++++++++++++++++++++++++++- > 1 file changed, 38 insertions(+), 1 deletion(-) > > diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c > index 291cc9c..1b78216 100644 > --- a/kernel/locking/lockdep.c > +++ b/kernel/locking/lockdep.c > @@ -3107,6 +3107,7 @@ typedef int (*check_usage_f)(struct task_struct *, struct held_lock *, > int excl_bit = exclusive_bit(new_bit); > int read = new_bit & LOCK_USAGE_READ_MASK; > int dir = new_bit & LOCK_USAGE_DIR_MASK; > + struct lock_class *lock = hlock_class(this); > > /* > * mark USED_IN has to look forwards -- to ensure no dependency > @@ -3119,6 +3120,25 @@ typedef int (*check_usage_f)(struct task_struct *, struct held_lock *, > check_usage_backwards : check_usage_forwards; > > /* > + * The bit is already marked so that we update the bitmaps > + * before validation. > + */ > + if (!dir) { > + unsigned long *bitmaps[4] = { > + lock_classes_hardirq_safe, > + lock_classes_hardirq_safe_read, > + lock_classes_softirq_safe, > + lock_classes_softirq_safe_read
That again should be something CPP magic using lockdep_states.h.
Also, that array can be static const, right? It's just an index into the static bitmaps.
> + }; > + int index = (new_bit >> 2) << 1; > + > + if (read) > + index += 1; > + > + __set_bit(lock - lock_classes, bitmaps[index]); > + } > + > + /* > * Validate that this particular lock does not have conflicting > * usage states. > */ > @@ -3146,7 +3166,7 @@ typedef int (*check_usage_f)(struct task_struct *, struct held_lock *, > return 0; > } > > - if (state_verbose(new_bit, hlock_class(this))) > + if (state_verbose(new_bit, lock)) > return 2; > > return 1; > @@ -4650,6 +4670,22 @@ static void remove_class_from_lock_chains(struct pending_free *pf, > } > } > > +static inline void remove_irqsafe_lock_bitmap(struct lock_class *class) > +{ > +#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING) > + unsigned long usage = class->usage_mask; > + > + if (usage & LOCKF_USED_IN_HARDIRQ) > + __clear_bit(class - lock_classes, lock_classes_hardirq_safe); > + if (usage & LOCKF_USED_IN_HARDIRQ_READ) > + __clear_bit(class - lock_classes, lock_classes_hardirq_safe_read); > + if (usage & LOCKF_USED_IN_SOFTIRQ) > + __clear_bit(class - lock_classes, lock_classes_softirq_safe); > + if (usage & LOCKF_USED_IN_SOFTIRQ_READ) > + __clear_bit(class - lock_classes, lock_classes_softirq_safe_read);
More CPP foo required here. Also, do we really need to test, we could just unconditionally clear the bits.
> +#endif > +}
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