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Protect interface and address lists using the appropriate mutex. These

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locks were not aquired because the user buffers were not wired, thus it was
possible that that SYSCTL_OUT could sleep, causing a number of different
problems such as lock ordering issues and dead locks.

-Wire user supplied buffer to ensure SYSCTL_OUT will not sleep.
-Pickup ifnet locks to protect the list.
-Where applicable pickup address locks.
-Pickup radix node head locks.
-Remove splnet stubs
-Remove various comments about locking here, because they are no
 longer needed.

It is the hope that these changes will make sysctl_rtsock MP safe.

MFC after:	3 weeks
This commit is contained in:
Christian S.J. Peron 2005-09-10 15:12:24 +00:00
parent 35a4bf1ce0
commit fe0fc7efe3
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=149943
1 changed files with 16 additions and 16 deletions
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32
sys/net/rtsock.c
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@ -1089,7 +1089,7 @@ sysctl_iflist(int af, struct walkarg *w)
int len, error = 0;
bzero((caddr_t)&info, sizeof(info));
/* IFNET_RLOCK(); */ /* could sleep XXX */
IFNET_RLOCK();
TAILQ_FOREACH(ifp, &ifnet, if_link) {
if (w->w_arg && w->w_arg != ifp->if_index)
continue;
@ -1136,7 +1136,7 @@ sysctl_iflist(int af, struct walkarg *w)
info.rti_info[RTAX_BRD] = NULL;
}
done:
/* IFNET_RUNLOCK(); */ /* XXX */
IFNET_RUNLOCK();
return (error);
}
@ -1150,17 +1150,13 @@ sysctl_ifmalist(int af, struct walkarg *w)
struct ifaddr *ifa;
bzero((caddr_t)&info, sizeof(info));
/* IFNET_RLOCK(); */ /* could sleep XXX */
IFNET_RLOCK();
TAILQ_FOREACH(ifp, &ifnet, if_link) {
if (w->w_arg && w->w_arg != ifp->if_index)
continue;
ifa = ifaddr_byindex(ifp->if_index);
info.rti_info[RTAX_IFP] = ifa ? ifa->ifa_addr : NULL;
/*
* XXXRW: Can't acquire IF_ADDR_LOCK() due to call
* to SYSCTL_OUT().
*/
IF_ADDR_LOCK(ifp);
TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
if (af && af != ifma->ifma_addr->sa_family)
continue;
@ -1180,13 +1176,16 @@ sysctl_ifmalist(int af, struct walkarg *w)
ifmam->ifmam_flags = 0;
ifmam->ifmam_addrs = info.rti_addrs;
error = SYSCTL_OUT(w->w_req, w->w_tmem, len);
if (error)
if (error) {
IF_ADDR_UNLOCK(ifp);
goto done;
}
}
}
IF_ADDR_UNLOCK(ifp);
}
done:
/* IFNET_RUNLOCK(); */ /* XXX */
IFNET_RUNLOCK();
return (error);
}
@ -1196,7 +1195,7 @@ sysctl_rtsock(SYSCTL_HANDLER_ARGS)
int *name = (int *)arg1;
u_int namelen = arg2;
struct radix_node_head *rnh;
int i, lim, s, error = EINVAL;
int i, lim, error = EINVAL;
u_char af;
struct walkarg w;
@ -1214,7 +1213,9 @@ sysctl_rtsock(SYSCTL_HANDLER_ARGS)
w.w_arg = name[2];
w.w_req = req;
s = splnet();
error = sysctl_wire_old_buffer(req, 0);
if (error)
return (error);
switch (w.w_op) {
case NET_RT_DUMP:
@ -1226,10 +1227,10 @@ sysctl_rtsock(SYSCTL_HANDLER_ARGS)
i = lim = af;
for (error = 0; error == 0 && i <= lim; i++)
if ((rnh = rt_tables[i]) != NULL) {
/* RADIX_NODE_HEAD_LOCK(rnh); */
RADIX_NODE_HEAD_LOCK(rnh);
error = rnh->rnh_walktree(rnh,
sysctl_dumpentry, &w);/* could sleep XXX */
/* RADIX_NODE_HEAD_UNLOCK(rnh); */
sysctl_dumpentry, &w);
RADIX_NODE_HEAD_UNLOCK(rnh);
} else if (af != 0)
error = EAFNOSUPPORT;
break;
@ -1242,7 +1243,6 @@ sysctl_rtsock(SYSCTL_HANDLER_ARGS)
error = sysctl_ifmalist(af, &w);
break;
}
splx(s);
if (w.w_tmem)
free(w.w_tmem, M_RTABLE);
return (error);