[PATCH] Minor fixes to netinet6/icmp6.c

Bjoern A. Zeeb bz at freebsd.org
Fri Dec 23 20:51:35 UTC 2011


On 23. Dec 2011, at 19:46 , John Baldwin wrote:

> I found these nits while working on the patches to convert if_addr_mtx to an 
> rwlock.  The first change is cosmetic, it just un-inlines a TAILQ_FOREACH().  
> The second change is an actual bug.  The code is currently reading 
> TAILQ_FIRST(&V_ifnet) without holding the appropriate lock.

I think they should be good; may I ask you to fix the locking in one commit and
the "style" foreach one in another?

/bz


> Index: icmp6.c
> ===================================================================
> --- icmp6.c	(revision 228777)
> +++ icmp6.c	(working copy)
> @@ -1780,7 +1780,7 @@ ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf
> 	}
> 
> 	IFNET_RLOCK_NOSLEEP();
> -	for (ifp = TAILQ_FIRST(&V_ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
> +	TAILQ_FOREACH(ifp, &V_ifnet, if_list) {
> 		addrsofif = 0;
> 		IF_ADDR_LOCK(ifp);
> 		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
> @@ -1851,7 +1851,7 @@ static int
> ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
>     struct ifnet *ifp0, int resid)
> {
> -	struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet);
> +	struct ifnet *ifp;
> 	struct in6_ifaddr *ifa6;
> 	struct ifaddr *ifa;
> 	struct ifnet *ifp_dep = NULL;
> @@ -1864,6 +1864,7 @@ ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct
> 		return (0);	/* needless to copy */
> 
> 	IFNET_RLOCK_NOSLEEP();
> +	ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet);
>   again:
> 
> 	for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
> 
> -- 
> John Baldwin

-- 
Bjoern A. Zeeb                                 You have to have visions!
         Stop bit received. Insert coin for new address family.



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