Messages in this thread | | | Date | Mon, 14 Feb 2022 12:25:16 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH 1/2] locking/lockdep: Cleanup reinit_class() |
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On Thu, Feb 10, 2022 at 10:55:25PM -0500, Waiman Long wrote: > Replace the duplicated WARN_ON_ONCE() tests in reinit_class() with > BUILD_BUG_ON(). > > Signed-off-by: Waiman Long <longman@redhat.com> > --- > include/linux/lockdep_types.h | 4 ++++ > kernel/locking/lockdep.c | 6 +++--- > 2 files changed, 7 insertions(+), 3 deletions(-) > > diff --git a/include/linux/lockdep_types.h b/include/linux/lockdep_types.h > index d22430840b53..446d981ae3a2 100644 > --- a/include/linux/lockdep_types.h > +++ b/include/linux/lockdep_types.h > @@ -108,6 +108,10 @@ struct lock_class { > */ > struct list_head locks_after, locks_before; > > + /* > + * All the fields that require re-initialization after being zapped > + * must be put after "key". > + */ > const struct lockdep_subclass_key *key; > unsigned int subclass; > unsigned int dep_gen_id; > diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c > index d4252b5c9863..77bbe557d48b 100644 > --- a/kernel/locking/lockdep.c > +++ b/kernel/locking/lockdep.c > @@ -6015,10 +6015,10 @@ static void reinit_class(struct lock_class *class) > WARN_ON_ONCE(!class->lock_entry.next); > WARN_ON_ONCE(!list_empty(&class->locks_after)); > WARN_ON_ONCE(!list_empty(&class->locks_before)); > + BUILD_BUG_ON(offsetof(struct lock_class, lock_entry) > offset); > + BUILD_BUG_ON(offsetof(struct lock_class, locks_after) > offset); > + BUILD_BUG_ON(offsetof(struct lock_class, locks_before) > offset); > memset(p + offset, 0, sizeof(*class) - offset); > - WARN_ON_ONCE(!class->lock_entry.next); > - WARN_ON_ONCE(!list_empty(&class->locks_after)); > - WARN_ON_ONCE(!list_empty(&class->locks_before)); > } > > static inline int within(const void *addr, void *start, unsigned long size) > -- > 2.27.0 >
Yeah, except that this doesn't build because it conflicts with a previous patch you actually Acked:
https://lore.kernel.org/all/20211213132618.105737-1-xiujianfeng@huawei.com/T/#m0e9474a9204ec29fb2135135ce3134640a3f27b5
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