Re: CVS commit: src/sys/net

[maya%netbsd.org@localhost]

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);
>