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Fix a LOR by dropping the global ifnet locks while allocating a new ifnet

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table in if_grow().  The order of the SYSINIT's for ifnet state were swapped
so that the various locks were initialized before being used.

Reviewed by:	pluknet, bz
MFC after:	2 weeks
This commit is contained in:
John Baldwin 2011-01-24 22:21:58 +00:00
parent f1fb96475a
commit 5f3b301a43
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=217805
1 changed files with 20 additions and 6 deletions
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26
sys/net/if.c
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@ -266,6 +266,7 @@ ifindex_alloc_locked(u_short *idxp)
IFNET_WLOCK_ASSERT();
retry:
/*
* Try to find an empty slot below V_if_index. If we fail, take the
* next slot.
@ -278,10 +279,12 @@ ifindex_alloc_locked(u_short *idxp)
/* Catch if_index overflow. */
if (idx < 1)
return (ENOSPC);
if (idx >= V_if_indexlim) {
if_grow();
goto retry;
}
if (idx > V_if_index)
V_if_index = idx;
if (V_if_index >= V_if_indexlim)
if_grow();
*idxp = idx;
return (0);
}
@ -351,10 +354,12 @@ vnet_if_init(const void *unused __unused)
TAILQ_INIT(&V_ifnet);
TAILQ_INIT(&V_ifg_head);
IFNET_WLOCK();
if_grow(); /* create initial table */
IFNET_WUNLOCK();
vnet_if_clone_init();
}
VNET_SYSINIT(vnet_if_init, SI_SUB_INIT_IF, SI_ORDER_FIRST, vnet_if_init,
VNET_SYSINIT(vnet_if_init, SI_SUB_INIT_IF, SI_ORDER_SECOND, vnet_if_init,
NULL);
/* ARGSUSED*/
@ -365,7 +370,7 @@ if_init(void *dummy __unused)
IFNET_LOCK_INIT();
if_clone_init();
}
SYSINIT(interfaces, SI_SUB_INIT_IF, SI_ORDER_SECOND, if_init, NULL);
SYSINIT(interfaces, SI_SUB_INIT_IF, SI_ORDER_FIRST, if_init, NULL);
#ifdef VIMAGE
@ -385,16 +390,25 @@ VNET_SYSUNINIT(vnet_if_uninit, SI_SUB_INIT_IF, SI_ORDER_FIRST,
static void
if_grow(void)
{
int oldlim;
u_int n;
struct ifindex_entry *e;
V_if_indexlim <<= 1;
n = V_if_indexlim * sizeof(*e);
IFNET_WLOCK_ASSERT();
oldlim = V_if_indexlim;
IFNET_WUNLOCK();
n = (oldlim << 1) * sizeof(*e);
e = malloc(n, M_IFNET, M_WAITOK | M_ZERO);
IFNET_WLOCK();
if (V_if_indexlim != oldlim) {
free(e, M_IFNET);
return;
}
if (V_ifindex_table != NULL) {
memcpy((caddr_t)e, (caddr_t)V_ifindex_table, n/2);
free((caddr_t)V_ifindex_table, M_IFNET);
}
V_if_indexlim <<= 1;
V_ifindex_table = e;
}