Re: + kernel-locking-lockdepc-make-lockdep-initialize-itself-on-demand.patch added to -mm tree

From: Ingo Molnar
Date: Mon Feb 29 2016 - 04:11:27 EST



* Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:

> On Tue, 9 Feb 2016 12:12:29 +0100 Ingo Molnar <mingo@xxxxxxxxxx> wrote:
>
> > > The conceptual problem is that if some piece of code does spin_lock_init() or
> > > DEFINE_SPINLOCK(), that lock isn't necessarily initialized yet.
> >
> > The conceptual problem is that the data structures are not build time initialized
> > - but the hlist conversion patch solves that problem nicely!
> >
> > So I'm a happy camper.
>
> OK, so the below has been in -next for nearly a week, no issues. We
> should get this into 4.5 to fix the CONFIG_UBSAN_ALIGNMENT issue.

So I think this patch broke liblockdep:

triton:~/tip/tools/lib/lockdep>

In file included from lockdep.c:2:0:
../../../kernel/locking/lockdep.c: In function âlook_up_lock_classâ:
../../../kernel/locking/lockdep.c:722:2: warning: implicit declaration of function âhlist_for_each_entry_rcuâ [-Wimplicit-function-declaration]
hlist_for_each_entry_rcu(class, hash_head, hash_entry) {

...

Thanks,

Ingo