Re: git: 9b967bd65de6 - main - domains: allow domains to be unloaded

On Sun, Aug 14, 2022 at 2:22 AM Alexander V. Chernikov
<melifaro@freebsd.org> wrote:
>
> The branch main has been updated by melifaro:
>
> URL: https://cgit.FreeBSD.org/src/commit/?id=9b967bd65de6647aed68a141dc34f9b223a2593c
>
> commit 9b967bd65de6647aed68a141dc34f9b223a2593c
> Author:     Alexander V. Chernikov <melifaro@FreeBSD.org>
> AuthorDate: 2022-08-12 13:36:53 +0000
> Commit:     Alexander V. Chernikov <melifaro@FreeBSD.org>
> CommitDate: 2022-08-14 09:22:33 +0000
>
>     domains: allow domains to be unloaded
>
>     Add domain_remove() SYSUNINT callback that removes the domain
>      from the domain list if it has DOMF_UNLOADABLE flag set.
>     This change is required to support netlink ( D36002 ).
>
>     Reviewed by:    glebius
>     Differential Revision: https://reviews.freebsd.org/D36173
> ---
>  sys/kern/uipc_domain.c | 23 +++++++++++++++++++++++
>  sys/sys/domain.h       |  4 ++++
>  2 files changed, 27 insertions(+)
>
> diff --git a/sys/kern/uipc_domain.c b/sys/kern/uipc_domain.c
> index c70b3150cbf0..2cae08be089a 100644
> --- a/sys/kern/uipc_domain.c
> +++ b/sys/kern/uipc_domain.c
> @@ -239,6 +239,29 @@ domain_add(void *data)
>         mtx_unlock(&dom_mtx);
>  }
>
> +void
> +domain_remove(void *data)
> +{
> +       struct domain *dp = (struct domain *)data;
> +
> +       if ((dp->dom_flags & DOMF_UNLOADABLE) == 0)
> +               return;
> +
> +       mtx_lock(&dom_mtx);
> +       if (domains == dp) {
> +               domains = dp->dom_next;
> +       } else {
> +               struct domain *curr;
> +               for (curr = domains; curr != NULL; curr = curr->dom_next) {
> +                       if (curr->dom_next == dp) {
> +                               curr->dom_next = dp->dom_next;
> +                               break;
> +                       }
> +               }
> +       }
> +       mtx_unlock(&dom_mtx);
> +}
> +
>  /* ARGSUSED*/
>  static void
>  domaininit(void *dummy)

While it's not important for the one domain you care about, this
should likely also check if any contained protocols have
pr_fasttimo/pr_slowtimo and purge them from the appropriate list, just
to be technically correct. (Or at least assert under INVARIANTS that
they do not)