Re: hyperv(4): use shared netlock to protect if_list and ifa_list walkthrough and data

[Alexander Bluhm]

On Mon, Sep 18, 2023 at 11:40:28AM +0300, Vitaliy Makkoveev wrote:
> Context switch looks fine here.

OK bluhm@

> Index: sys/dev/pv/hypervic.c
> ===================================================================
> RCS file: /cvs/src/sys/dev/pv/hypervic.c,v
> retrieving revision 1.19
> diff -u -p -r1.19 hypervic.c
> --- sys/dev/pv/hypervic.c     11 Apr 2023 00:45:08 -0000      1.19
> +++ sys/dev/pv/hypervic.c     18 Sep 2023 08:35:02 -0000
> @@ -846,7 +846,7 @@ kvp_get_ip_info(struct hv_kvp *kvp, cons
>       struct sockaddr_in6 *sin6, sa6;
>       uint8_t enaddr[ETHER_ADDR_LEN];
>       uint8_t ipaddr[INET6_ADDRSTRLEN];
> -     int i, j, lo, hi, s, af;
> +     int i, j, lo, hi, af;
>  
>       /* Convert from the UTF-16LE string format to binary */
>       for (i = 0, j = 0; j < ETHER_ADDR_LEN; i += 6) {
> @@ -870,16 +870,14 @@ kvp_get_ip_info(struct hv_kvp *kvp, cons
>               return (-1);
>       }
>  
> -     KERNEL_LOCK();
> -     s = splnet();
> +     NET_LOCK_SHARED();
>  
>       TAILQ_FOREACH(ifp, &ifnetlist, if_list) {
>               if (!memcmp(LLADDR(ifp->if_sadl), enaddr, ETHER_ADDR_LEN))
>                       break;
>       }
>       if (ifp == NULL) {
> -             splx(s);
> -             KERNEL_UNLOCK();
> +             NET_UNLOCK_SHARED();
>               return (-1);
>       }
>  
> @@ -919,8 +917,7 @@ kvp_get_ip_info(struct hv_kvp *kvp, cons
>               else if (ifa6ll != NULL)
>                       ifa = ifa6ll;
>               else {
> -                     splx(s);
> -                     KERNEL_UNLOCK();
> +                     NET_UNLOCK_SHARED();
>                       return (-1);
>               }
>       }
> @@ -956,8 +953,7 @@ kvp_get_ip_info(struct hv_kvp *kvp, cons
>               break;
>       }
>  
> -     splx(s);
> -     KERNEL_UNLOCK();
> +     NET_UNLOCK_SHARED();
>  
>       return (0);
>  }