Build on Jeff Roberson's linker-set based dynamic per-CPU allocator

(DPCPU), as suggested by Peter Wemm, and implement a new per-virtual
network stack memory allocator.  Modify vnet to use the allocator
instead of monolithic global container structures (vinet, ...).  This
change solves many binary compatibility problems associated with
VIMAGE, and restores ELF symbols for virtualized global variables.

Each virtualized global variable exists as a "reference copy", and also
once per virtual network stack.  Virtualized global variables are
tagged at compile-time, placing the in a special linker set, which is
loaded into a contiguous region of kernel memory.  Virtualized global
variables in the base kernel are linked as normal, but those in modules
are copied and relocated to a reserved portion of the kernel's vnet
region with the help of a the kernel linker.

Virtualized global variables exist in per-vnet memory set up when the
network stack instance is created, and are initialized statically from
the reference copy.  Run-time access occurs via an accessor macro, which
converts from the current vnet and requested symbol to a per-vnet
address.  When "options VIMAGE" is not compiled into the kernel, normal
global ELF symbols will be used instead and indirection is avoided.

This change restores static initialization for network stack global
variables, restores support for non-global symbols and types, eliminates
the need for many subsystem constructors, eliminates large per-subsystem
structures that caused many binary compatibility issues both for
monitoring applications (netstat) and kernel modules, removes the
per-function INIT_VNET_*() macros throughout the stack, eliminates the
need for vnet_symmap ksym(2) munging, and eliminates duplicate
definitions of virtualized globals under VIMAGE_GLOBALS.

Bump __FreeBSD_version and update UPDATING.

Portions submitted by:  bz
Reviewed by:            bz, zec
Discussed with:         gnn, jamie, jeff, jhb, julian, sam
Suggested by:           peter
Approved by:            re (kensmith)

1 files changed, 6 insertions, 20 deletions

diff --git a/sys/netinet6/in6_src.c b/sys/netinet6/in6_src.c
index f1ccca1..ffa6c3e 100644
--- a/sys/netinet6/in6_src.c
+++ b/sys/netinet6/in6_src.c
@@ -100,7 +100,6 @@ __FBSDID("$FreeBSD$");
 #include <netinet/ip_var.h>
 #include <netinet/udp.h>
 #include <netinet/udp_var.h>
-#include <netinet/vinet.h>
 
 #include <netinet6/in6_var.h>
 #include <netinet/ip6.h>
@@ -108,7 +107,6 @@ __FBSDID("$FreeBSD$");
 #include <netinet6/ip6_var.h>
 #include <netinet6/scope6_var.h>
 #include <netinet6/nd6.h>
-#include <netinet6/vinet6.h>
 
 static struct mtx addrsel_lock;
 #define	ADDRSEL_LOCK_INIT()	mtx_init(&addrsel_lock, "addrsel_lock", NULL, MTX_DEF)
@@ -125,10 +123,10 @@ static struct sx addrsel_sxlock;
 
 #define ADDR_LABEL_NOTAPP (-1)
 
-#ifdef VIMAGE_GLOBALS
-struct in6_addrpolicy defaultaddrpolicy;
-int ip6_prefer_tempaddr;
-#endif
+static VNET_DEFINE(struct in6_addrpolicy, defaultaddrpolicy);
+VNET_DEFINE(int, ip6_prefer_tempaddr);
+
+#define	V_defaultaddrpolicy		VNET_GET(defaultaddrpolicy)
 
 static int selectroute __P((struct sockaddr_in6 *, struct ip6_pktopts *,
 	struct ip6_moptions *, struct route_in6 *, struct ifnet **,
@@ -184,7 +182,6 @@ in6_selectsrc(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
     struct inpcb *inp, struct route_in6 *ro, struct ucred *cred,
     struct ifnet **ifpp, struct in6_addr *srcp)
 {
-	INIT_VNET_INET6(curvnet);
 	struct in6_addr dst;
 	struct ifnet *ifp = NULL;
 	struct in6_ifaddr *ia = NULL, *ia_best = NULL;
@@ -488,7 +485,6 @@ selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
     struct ip6_moptions *mopts, struct route_in6 *ro,
     struct ifnet **retifp, struct rtentry **retrt, int norouteok)
 {
-	INIT_VNET_INET6(curvnet);
 	int error = 0;
 	struct ifnet *ifp = NULL;
 	struct rtentry *rt = NULL;
@@ -793,7 +789,6 @@ in6_selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
 int
 in6_selecthlim(struct inpcb *in6p, struct ifnet *ifp)
 {
-	INIT_VNET_INET6(curvnet);
 
 	if (in6p && in6p->in6p_hops >= 0)
 		return (in6p->in6p_hops);
@@ -826,7 +821,6 @@ in6_selecthlim(struct inpcb *in6p, struct ifnet *ifp)
 int
 in6_pcbsetport(struct in6_addr *laddr, struct inpcb *inp, struct ucred *cred)
 {
-	INIT_VNET_INET(curvnet);
 	struct socket *so = inp->inp_socket;
 	u_int16_t lport = 0, first, last, *lastport;
 	int count, error, wild = 0, dorandom;
@@ -928,7 +922,6 @@ in6_pcbsetport(struct in6_addr *laddr, struct inpcb *inp, struct ucred *cred)
 void
 addrsel_policy_init(void)
 {
-	INIT_VNET_INET6(curvnet);
 
 	V_ip6_prefer_tempaddr = 0;
 
@@ -948,7 +941,6 @@ addrsel_policy_init(void)
 static struct in6_addrpolicy *
 lookup_addrsel_policy(struct sockaddr_in6 *key)
 {
-	INIT_VNET_INET6(curvnet);
 	struct in6_addrpolicy *match = NULL;
 
 	ADDRSEL_LOCK();
@@ -1035,14 +1027,12 @@ struct addrsel_policyent {
 
 TAILQ_HEAD(addrsel_policyhead, addrsel_policyent);
 
-#ifdef VIMAGE_GLOBALS
-struct addrsel_policyhead addrsel_policytab;
-#endif
+static VNET_DEFINE(struct addrsel_policyhead, addrsel_policytab);
+#define	V_addrsel_policytab		VNET_GET(addrsel_policytab)
 
 static void
 init_policy_queue(void)
 {
-	INIT_VNET_INET6(curvnet);
 
 	TAILQ_INIT(&V_addrsel_policytab);
 }
@@ -1050,7 +1040,6 @@ init_policy_queue(void)
 static int
 add_addrsel_policyent(struct in6_addrpolicy *newpolicy)
 {
-	INIT_VNET_INET6(curvnet);
 	struct addrsel_policyent *new, *pol;
 
 	new = malloc(sizeof(*new), M_IFADDR,
@@ -1086,7 +1075,6 @@ add_addrsel_policyent(struct in6_addrpolicy *newpolicy)
 static int
 delete_addrsel_policyent(struct in6_addrpolicy *key)
 {
-	INIT_VNET_INET6(curvnet);
 	struct addrsel_policyent *pol;
 
 	ADDRSEL_XLOCK();
@@ -1118,7 +1106,6 @@ static int
 walk_addrsel_policy(int (*callback)(struct in6_addrpolicy *, void *),
     void *w)
 {
-	INIT_VNET_INET6(curvnet);
 	struct addrsel_policyent *pol;
 	int error = 0;
 
@@ -1147,7 +1134,6 @@ dump_addrsel_policyent(struct in6_addrpolicy *pol, void *arg)
 static struct in6_addrpolicy *
 match_addrsel_policy(struct sockaddr_in6 *key)
 {
-	INIT_VNET_INET6(curvnet);
 	struct addrsel_policyent *pent;
 	struct in6_addrpolicy *bestpol = NULL, *pol;
 	int matchlen, bestmatchlen = -1;