This is causing PR kern/52914 (on netbsd-8, not current)
On Fri, Dec 15, 2017 at 04:04:59AM +0000, Ryota Ozaki wrote:
> Module Name: src
> Committed By: ozaki-r
> Date: Fri Dec 15 04:04:59 UTC 2017
>
> Modified Files:
> src/sys/net: if.c
>
> Log Message:
> Remove IFNET_GLOBAL_LOCK where it's unnecessary because IFNET_LOCK is held
>
>
> To generate a diff of this commit:
> cvs rdiff -u -r1.415 -r1.416 src/sys/net/if.c
>
> Please note that diffs are not public domain; they are subject to the
> copyright notices on the relevant files.
>
> Modified files:
>
> Index: src/sys/net/if.c
> diff -u src/sys/net/if.c:1.415 src/sys/net/if.c:1.416
> --- src/sys/net/if.c:1.415 Fri Dec 15 04:03:46 2017
> +++ src/sys/net/if.c Fri Dec 15 04:04:58 2017
> @@ -1,4 +1,4 @@
> -/* $NetBSD: if.c,v 1.415 2017/12/15 04:03:46 ozaki-r Exp $ */
> +/* $NetBSD: if.c,v 1.416 2017/12/15 04:04:58 ozaki-r Exp $ */
>
> /*-
> * Copyright (c) 1999, 2000, 2001, 2008 The NetBSD Foundation, Inc.
> @@ -90,7 +90,7 @@
> */
>
> #include <sys/cdefs.h>
> -__KERNEL_RCSID(0, "$NetBSD: if.c,v 1.415 2017/12/15 04:03:46 ozaki-r Exp $");
> +__KERNEL_RCSID(0, "$NetBSD: if.c,v 1.416 2017/12/15 04:04:58 ozaki-r Exp $");
>
> #if defined(_KERNEL_OPT)
> #include "opt_inet.h"
> @@ -1792,11 +1792,18 @@ ifa_insert(struct ifnet *ifp, struct ifa
>
> ifa->ifa_ifp = ifp;
>
> - IFNET_GLOBAL_LOCK();
> + /*
> + * Check !IFF_RUNNING for initialization routines that normally don't
> + * take IFNET_LOCK but it's safe because there is no competitor.
> + * XXX there are false positive cases because IFF_RUNNING can be off on
> + * if_stop.
> + */
> + KASSERT(!ISSET(ifp->if_flags, IFF_RUNNING) ||
> + IFNET_LOCKED(ifp));
> +
> TAILQ_INSERT_TAIL(&ifp->if_addrlist, ifa, ifa_list);
> IFADDR_ENTRY_INIT(ifa);
> IFADDR_WRITER_INSERT_TAIL(ifp, ifa);
> - IFNET_GLOBAL_UNLOCK();
>
> ifaref(ifa);
> }
> @@ -1806,14 +1813,19 @@ ifa_remove(struct ifnet *ifp, struct ifa
> {
>
> KASSERT(ifa->ifa_ifp == ifp);
> + /*
> + * if_is_deactivated indicates ifa_remove is called form if_detach
> + * where is safe even if IFNET_LOCK isn't held.
> + */
> + KASSERT(if_is_deactivated(ifp) || IFNET_LOCKED(ifp));
>
> - IFNET_GLOBAL_LOCK();
> TAILQ_REMOVE(&ifp->if_addrlist, ifa, ifa_list);
> IFADDR_WRITER_REMOVE(ifa);
> #ifdef NET_MPSAFE
> + IFNET_GLOBAL_LOCK();
> pserialize_perform(ifnet_psz);
> -#endif
> IFNET_GLOBAL_UNLOCK();
> +#endif
>
> #ifdef NET_MPSAFE
> psref_target_destroy(&ifa->ifa_psref, ifa_psref_class);
>
