Re: git: 7ae879b14a20 - main - kern_procctl(): convert the function to be table-driven

In message <d2c0d3d7-a993-37c2-3fa7-aac8f30e9508@FreeBSD.org>, John Baldwin 
wri
tes:
> On 10/19/21 1:51 PM, Cy Schubert wrote:
> > In message <91ebf9d8-5547-8570-18cb-26a58baf89ba@FreeBSD.org>, John Baldwin
> > wri
> > tes:
> >> On 10/19/21 1:35 PM, Cy Schubert wrote:
> >>> In message <202110192004.19JK4jN3069844@gitrepo.freebsd.org>, Konstantin
> >>> Belous
> >>> ov writes:
> >>>> The branch main has been updated by kib:
> >>>>
> >>>> URL: https://cgit.FreeBSD.org/src/commit/?id=7ae879b14a2086df521c59c4a37
> 9d
> >> 3a0
> >>>> 72e08bc6
> >>>>
> >>>> commit 7ae879b14a2086df521c59c4a379d3a072e08bc6
> >>>> Author:     Konstantin Belousov <kib@FreeBSD.org>
> >>>> AuthorDate: 2021-10-15 18:57:17 +0000
> >>>> Commit:     Konstantin Belousov <kib@FreeBSD.org>
> >>>> CommitDate: 2021-10-19 20:04:34 +0000
> >>>>
> >>>>       kern_procctl(): convert the function to be table-driven
> >>>>       
> >>>>       Reviewed by:    emaste, markj
> >>>>       Sponsored by:   The FreeBSD Foundation
> >>>>       MFC after:      1 week
> >>>>       Differential revision:  https://reviews.freebsd.org/D32513
> >>>> ---
> >>>>    sys/kern/kern_procctl.c | 123 +++++++++++++++++++++++++++------------
> ---
> >> ----
> >>>> --
> >>>>    1 file changed, 69 insertions(+), 54 deletions(-)
> >>>>
> >>>> diff --git a/sys/kern/kern_procctl.c b/sys/kern/kern_procctl.c
> >>>> index eb36f0822938..90c5e63c7219 100644
> >>>> --- a/sys/kern/kern_procctl.c
> >>>> +++ b/sys/kern/kern_procctl.c
> >>>> @@ -949,7 +957,14 @@ kern_procctl(struct thread *td, idtype_t idtype, id
> _t
> >>   id
> >>>> , int com, void *data)
> >>>>    		error = EINVAL;
> >>>>    		break;
> >>>>    	}
> >>>> -	if (tree_locked)
> >>>> -		sx_unlock(&proctree_lock);
> >>>> +
> >>>> +	switch (cmd_info->lock_tree) {
> >>>> +	case SA_XLOCKED:
> >>>> +		sx_xunlock(&proctree_lock);
> >>>> +		break;
> >>>> +	case SA_SLOCKED:
> >>>> +		sx_sunlock(&proctree_lock);
> >>>> +		break;
> >>>> +	}
> >>>>    	return (error);
> >>>>    }
> >>>>
> >>>
> >>> Should SA_* in fact be LA_*? SA_* in sys/sx.h assumes INVARIANTS whereas
> >>> LA_* in sys/lock.h has no such requirement.
> >>
> >> Both are for "assertions".  The LA_* constants aren't really public but ar
> e
> >> the values used for witness_assert() that various foo_assert() routines in
> >> locking APIs (mtx_assert/sx_assert, etc.) can use.  For locking APIs, the
> >> type-specific macros are the ones you use, e.g. SA_* with sx_assert().
> >>
> >> Given that, SA_* is the closest match here.
> > 
> > We'll need some #ifdefs for non-INVARIANTS built kernels, as it stands
> > buildkernel is broken.
>
> So it is helpeful if your e-mail starts with "the build is broken". :)

Sorry about that. Next time I will.

>
> That said, I think the issue is that SA_* (and LA_*) have to date only been
> used for assertions and are thus only relevant when INVARIANTS is defined.
> It's probably simplest to just expose SA_* always if that is what is
> needed.

Thinking the same thing.


-- 
Cheers,
Cy Schubert <Cy.Schubert@cschubert.com>
FreeBSD UNIX:  <cy@FreeBSD.org>   Web:  https://FreeBSD.org
NTP:           <cy@nwtime.org>    Web:  https://nwtime.org

	The need of the many outweighs the greed of the few.