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, 11 insertions, 34 deletions

diff --git a/sys/netinet/udp_usrreq.c b/sys/netinet/udp_usrreq.c
index 51dda23..f9623f3 100644
--- a/sys/netinet/udp_usrreq.c
+++ b/sys/netinet/udp_usrreq.c
@@ -80,7 +80,6 @@ __FBSDID("$FreeBSD$");
 #endif
 #include <netinet/udp.h>
 #include <netinet/udp_var.h>
-#include <netinet/vinet.h>
 
 #ifdef IPSEC
 #include <netipsec/ipsec.h>
@@ -96,9 +95,7 @@ __FBSDID("$FreeBSD$");
  * Per RFC 768, August, 1980.
  */
 
-#ifdef VIMAGE_GLOBALS
-int	udp_blackhole;
-#endif
+VNET_DEFINE(int, udp_blackhole);
 
 /*
  * BSD 4.2 defaulted the udp checksum to be off.  Turning off udp checksums
@@ -114,8 +111,8 @@ int	udp_log_in_vain = 0;
 SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_RW,
     &udp_log_in_vain, 0, "Log all incoming UDP packets");
 
-SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_udp, OID_AUTO, blackhole,
-    CTLFLAG_RW, udp_blackhole, 0,
+SYSCTL_VNET_INT(_net_inet_udp, OID_AUTO, blackhole, CTLFLAG_RW,
+    &VNET_NAME(udp_blackhole), 0,
     "Do not send port unreachables for refused connects");
 
 u_long	udp_sendspace = 9216;		/* really max datagram size */
@@ -134,19 +131,19 @@ u_long	udp_recvspace = 40 * (1024 +
 SYSCTL_ULONG(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
     &udp_recvspace, 0, "Maximum space for incoming UDP datagrams");
 
-#ifdef VIMAGE_GLOBALS
-struct inpcbhead	udb;		/* from udp_var.h */
-struct inpcbinfo	udbinfo;
-static uma_zone_t	udpcb_zone;
-struct udpstat		udpstat;	/* from udp_var.h */
-#endif
+VNET_DEFINE(struct inpcbhead, udb);		/* from udp_var.h */
+VNET_DEFINE(struct inpcbinfo, udbinfo);
+static VNET_DEFINE(uma_zone_t, udpcb_zone);
+VNET_DEFINE(struct udpstat, udpstat);		/* from udp_var.h */
+
+#define	V_udpcb_zone			VNET_GET(udpcb_zone)
 
 #ifndef UDBHASHSIZE
 #define	UDBHASHSIZE	128
 #endif
 
-SYSCTL_V_STRUCT(V_NET, vnet_inet, _net_inet_udp, UDPCTL_STATS, stats,
-    CTLFLAG_RW, udpstat, udpstat,
+SYSCTL_VNET_STRUCT(_net_inet_udp, UDPCTL_STATS, stats, CTLFLAG_RW,
+    &VNET_NAME(udpstat), udpstat,
     "UDP statistics (struct udpstat, netinet/udp_var.h)");
 
 static void	udp_detach(struct socket *so);
@@ -164,7 +161,6 @@ static struct mbuf *udp4_espdecap(struct inpcb *, struct mbuf *, int);
 static void
 udp_zone_change(void *tag)
 {
-	INIT_VNET_INET(curvnet);
 
 	uma_zone_set_max(V_udbinfo.ipi_zone, maxsockets);
 	uma_zone_set_max(V_udpcb_zone, maxsockets);
@@ -183,7 +179,6 @@ udp_inpcb_init(void *mem, int size, int flags)
 void
 udp_init(void)
 {
-	INIT_VNET_INET(curvnet);
 
 	V_udp_blackhole = 0;
 
@@ -212,7 +207,6 @@ udp_init(void)
 int
 udp_newudpcb(struct inpcb *inp)
 {
-	INIT_VNET_INET(curvnet);
 	struct udpcb *up;
 
 	up = uma_zalloc(V_udpcb_zone, M_NOWAIT | M_ZERO);
@@ -225,7 +219,6 @@ udp_newudpcb(struct inpcb *inp)
 void
 udp_discardcb(struct udpcb *up)
 {
-	INIT_VNET_INET(curvnet);
 
 	uma_zfree(V_udpcb_zone, up);
 }
@@ -234,7 +227,6 @@ udp_discardcb(struct udpcb *up)
 void
 udp_destroy(void)
 {
-	INIT_VNET_INET(curvnet);
 
 	hashdestroy(V_udbinfo.ipi_hashbase, M_PCB,
 	    V_udbinfo.ipi_hashmask);
@@ -274,7 +266,6 @@ udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off,
 #ifdef IPSEC
 	/* Check AH/ESP integrity. */
 	if (ipsec4_in_reject(n, inp)) {
-		INIT_VNET_IPSEC(curvnet);
 		m_freem(n);
 		V_ipsec4stat.in_polvio++;
 		return;
@@ -321,7 +312,6 @@ udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off,
 	so = inp->inp_socket;
 	SOCKBUF_LOCK(&so->so_rcv);
 	if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) {
-		INIT_VNET_INET(so->so_vnet);
 		SOCKBUF_UNLOCK(&so->so_rcv);
 		m_freem(n);
 		if (opts)
@@ -334,7 +324,6 @@ udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off,
 void
 udp_input(struct mbuf *m, int off)
 {
-	INIT_VNET_INET(curvnet);
 	int iphlen = off;
 	struct ip *ip;
 	struct udphdr *uh;
@@ -668,7 +657,6 @@ udp_notify(struct inpcb *inp, int errno)
 void
 udp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
 {
-	INIT_VNET_INET(curvnet);
 	struct ip *ip = vip;
 	struct udphdr *uh;
 	struct in_addr faddr;
@@ -715,7 +703,6 @@ udp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
 static int
 udp_pcblist(SYSCTL_HANDLER_ARGS)
 {
-	INIT_VNET_INET(curvnet);
 	int error, i, n;
 	struct inpcb *inp, **inp_list;
 	inp_gen_t gencnt;
@@ -814,7 +801,6 @@ SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0,
 static int
 udp_getcred(SYSCTL_HANDLER_ARGS)
 {
-	INIT_VNET_INET(curvnet);
 	struct xucred xuc;
 	struct sockaddr_in addrs[2];
 	struct inpcb *inp;
@@ -949,7 +935,6 @@ static int
 udp_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr,
     struct mbuf *control, struct thread *td)
 {
-	INIT_VNET_INET(inp->inp_vnet);
 	struct udpiphdr *ui;
 	int len = m->m_pkthdr.len;
 	struct in_addr faddr, laddr;
@@ -1270,7 +1255,6 @@ release:
 static struct mbuf *
 udp4_espdecap(struct inpcb *inp, struct mbuf *m, int off)
 {
-	INIT_VNET_IPSEC(curvnet);
 	size_t minlen, payload, skip, iphlen;
 	caddr_t data;
 	struct udpcb *up;
@@ -1397,7 +1381,6 @@ udp4_espdecap(struct inpcb *inp, struct mbuf *m, int off)
 static void
 udp_abort(struct socket *so)
 {
-	INIT_VNET_INET(so->so_vnet);
 	struct inpcb *inp;
 
 	inp = sotoinpcb(so);
@@ -1416,7 +1399,6 @@ udp_abort(struct socket *so)
 static int
 udp_attach(struct socket *so, int proto, struct thread *td)
 {
-	INIT_VNET_INET(so->so_vnet);
 	struct inpcb *inp;
 	int error;
 
@@ -1480,7 +1462,6 @@ udp_set_kernel_tunneling(struct socket *so, udp_tun_func_t f)
 static int
 udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 {
-	INIT_VNET_INET(so->so_vnet);
 	struct inpcb *inp;
 	int error;
 
@@ -1497,7 +1478,6 @@ udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 static void
 udp_close(struct socket *so)
 {
-	INIT_VNET_INET(so->so_vnet);
 	struct inpcb *inp;
 
 	inp = sotoinpcb(so);
@@ -1516,7 +1496,6 @@ udp_close(struct socket *so)
 static int
 udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
 {
-	INIT_VNET_INET(so->so_vnet);
 	struct inpcb *inp;
 	int error;
 	struct sockaddr_in *sin;
@@ -1548,7 +1527,6 @@ udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
 static void
 udp_detach(struct socket *so)
 {
-	INIT_VNET_INET(so->so_vnet);
 	struct inpcb *inp;
 	struct udpcb *up;
 
@@ -1570,7 +1548,6 @@ udp_detach(struct socket *so)
 static int
 udp_disconnect(struct socket *so)
 {
-	INIT_VNET_INET(so->so_vnet);
 	struct inpcb *inp;
 
 	inp = sotoinpcb(so);