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, 58 insertions, 88 deletions

diff --git a/sys/netinet/igmp.c b/sys/netinet/igmp.c
index be102d4..c8bd09a 100644
--- a/sys/netinet/igmp.c
+++ b/sys/netinet/igmp.c
@@ -75,7 +75,6 @@ __FBSDID("$FreeBSD$");
 #include <netinet/ip_options.h>
 #include <netinet/igmp.h>
 #include <netinet/igmp_var.h>
-#include <netinet/vinet.h>
 
 #include <machine/in_cksum.h>
 
@@ -212,55 +211,72 @@ MALLOC_DEFINE(M_IGMP, "igmp", "igmp state");
  * FUTURE: Stop using IFP_TO_IA/INADDR_ANY, and use source address selection
  * policy to control the address used by IGMP on the link.
  */
-#ifdef VIMAGE_GLOBALS
-int	 interface_timers_running;	 /* IGMPv3 general query response */
-int	 state_change_timers_running;	 /* IGMPv3 state-change retransmit */
-int	 current_state_timers_running;	 /* IGMPv1/v2 host report;
-					  * IGMPv3 g/sg query response */
-
-LIST_HEAD(, igmp_ifinfo)	 igi_head;
-struct igmpstat			 igmpstat;
-struct timeval			 igmp_gsrdelay;
-
-int	 igmp_recvifkludge;
-int	 igmp_sendra;
-int	 igmp_sendlocal;
-int	 igmp_v1enable;
-int	 igmp_v2enable;
-int	 igmp_legacysupp;
-int	 igmp_default_version;
-#endif /* VIMAGE_GLOBALS */
+static VNET_DEFINE(int, interface_timers_running);	/* IGMPv3 general
+							 * query response */
+static VNET_DEFINE(int, state_change_timers_running);	/* IGMPv3 state-change
+							 * retransmit */
+static VNET_DEFINE(int, current_state_timers_running);	/* IGMPv1/v2 host
+							 * report; IGMPv3 g/sg
+							 * query response */
+
+#define	V_interface_timers_running	VNET_GET(interface_timers_running)
+#define	V_state_change_timers_running	VNET_GET(state_change_timers_running)
+#define	V_current_state_timers_running	VNET_GET(current_state_timers_running)
+
+static VNET_DEFINE(LIST_HEAD(, igmp_ifinfo), igi_head);
+static VNET_DEFINE(struct igmpstat, igmpstat);
+static VNET_DEFINE(struct timeval, igmp_gsrdelay) = {10, 0};
+
+#define	V_igi_head			VNET_GET(igi_head)
+#define	V_igmpstat			VNET_GET(igmpstat)
+#define	V_igmp_gsrdelay			VNET_GET(igmp_gsrdelay)
+
+static VNET_DEFINE(int, igmp_recvifkludge) = 1;
+static VNET_DEFINE(int, igmp_sendra) = 1;
+static VNET_DEFINE(int, igmp_sendlocal) = 1;
+static VNET_DEFINE(int, igmp_v1enable) = 1;
+static VNET_DEFINE(int, igmp_v2enable) = 1;
+static VNET_DEFINE(int, igmp_legacysupp);
+static VNET_DEFINE(int, igmp_default_version) = IGMP_VERSION_3;
+
+#define	V_igmp_recvifkludge		VNET_GET(igmp_recvifkludge)
+#define	V_igmp_sendra			VNET_GET(igmp_sendra)
+#define	V_igmp_sendlocal		VNET_GET(igmp_sendlocal)
+#define	V_igmp_v1enable			VNET_GET(igmp_v1enable)
+#define	V_igmp_v2enable			VNET_GET(igmp_v2enable)
+#define	V_igmp_legacysupp		VNET_GET(igmp_legacysupp)
+#define	V_igmp_default_version		VNET_GET(igmp_default_version)
 
 /*
  * Virtualized sysctls.
  */
-SYSCTL_V_STRUCT(V_NET, vnet_inet, _net_inet_igmp, IGMPCTL_STATS, stats,
-    CTLFLAG_RW, igmpstat, igmpstat, "");
-SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_igmp, OID_AUTO, recvifkludge,
-    CTLFLAG_RW, igmp_recvifkludge, 0,
+SYSCTL_VNET_STRUCT(_net_inet_igmp, IGMPCTL_STATS, stats, CTLFLAG_RW,
+    &VNET_NAME(igmpstat), igmpstat, "");
+SYSCTL_VNET_INT(_net_inet_igmp, OID_AUTO, recvifkludge, CTLFLAG_RW,
+    &VNET_NAME(igmp_recvifkludge), 0,
     "Rewrite IGMPv1/v2 reports from 0.0.0.0 to contain subnet address");
-SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_igmp, OID_AUTO, sendra,
-    CTLFLAG_RW, igmp_sendra, 0,
+SYSCTL_VNET_INT(_net_inet_igmp, OID_AUTO, sendra, CTLFLAG_RW,
+    &VNET_NAME(igmp_sendra), 0,
     "Send IP Router Alert option in IGMPv2/v3 messages");
-SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_igmp, OID_AUTO, sendlocal,
-    CTLFLAG_RW, igmp_sendlocal, 0,
+SYSCTL_VNET_INT(_net_inet_igmp, OID_AUTO, sendlocal, CTLFLAG_RW,
+    &VNET_NAME(igmp_sendlocal), 0,
     "Send IGMP membership reports for 224.0.0.0/24 groups");
-SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_igmp, OID_AUTO, v1enable,
-    CTLFLAG_RW, igmp_v1enable, 0,
+SYSCTL_VNET_INT(_net_inet_igmp, OID_AUTO, v1enable, CTLFLAG_RW,
+    &VNET_NAME(igmp_v1enable), 0,
     "Enable backwards compatibility with IGMPv1");
-SYSCTL_V_INT(V_NET, vnet_inet,  _net_inet_igmp, OID_AUTO, v2enable,
-    CTLFLAG_RW, igmp_v2enable, 0,
+SYSCTL_VNET_INT(_net_inet_igmp, OID_AUTO, v2enable, CTLFLAG_RW,
+    &VNET_NAME(igmp_v2enable), 0,
     "Enable backwards compatibility with IGMPv2");
-SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_igmp, OID_AUTO, legacysupp,
-    CTLFLAG_RW, igmp_legacysupp, 0,
+SYSCTL_VNET_INT(_net_inet_igmp, OID_AUTO, legacysupp, CTLFLAG_RW,
+    &VNET_NAME(igmp_legacysupp), 0,
     "Allow v1/v2 reports to suppress v3 group responses");
-SYSCTL_V_PROC(V_NET, vnet_inet, _net_inet_igmp, OID_AUTO, default_version,
-    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, igmp_default_version, 0,
-    sysctl_igmp_default_version, "I",
+SYSCTL_VNET_PROC(_net_inet_igmp, OID_AUTO, default_version,
+    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
+    &VNET_NAME(igmp_default_version), 0, sysctl_igmp_default_version, "I",
     "Default version of IGMP to run on each interface");
-SYSCTL_V_PROC(V_NET, vnet_inet, _net_inet_igmp, OID_AUTO, gsrdelay,
-    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, igmp_gsrdelay.tv_sec, 0,
-    sysctl_igmp_gsr, "I",
+SYSCTL_VNET_PROC(_net_inet_igmp, OID_AUTO, gsrdelay,
+    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
+    &VNET_NAME(igmp_gsrdelay.tv_sec), 0, sysctl_igmp_gsr, "I",
     "Rate limit for IGMPv3 Group-and-Source queries in seconds");
 
 /*
@@ -327,7 +343,6 @@ igmp_restore_context(struct mbuf *m)
 static int
 sysctl_igmp_default_version(SYSCTL_HANDLER_ARGS)
 {
-	INIT_VNET_INET(curvnet);
 	int	 error;
 	int	 new;
 
@@ -367,7 +382,6 @@ out_locked:
 static int
 sysctl_igmp_gsr(SYSCTL_HANDLER_ARGS)
 {
-	INIT_VNET_INET(curvnet);
 	int error;
 	int i;
 
@@ -408,8 +422,6 @@ out_locked:
 static int
 sysctl_igmp_ifinfo(SYSCTL_HANDLER_ARGS)
 {
-	INIT_VNET_NET(curvnet);
-	INIT_VNET_INET(curvnet);
 	int			*name;
 	int			 error;
 	u_int			 namelen;
@@ -495,7 +507,6 @@ igmp_dispatch_queue(struct ifqueue *ifq, int limit, const int loop)
 static __inline int
 igmp_isgroupreported(const struct in_addr addr)
 {
-	INIT_VNET_INET(curvnet);
 
 	if (in_allhosts(addr) ||
 	    ((!V_igmp_sendlocal && IN_LOCAL_GROUP(ntohl(addr.s_addr)))))
@@ -553,7 +564,6 @@ igmp_domifattach(struct ifnet *ifp)
 static struct igmp_ifinfo *
 igi_alloc_locked(/*const*/ struct ifnet *ifp)
 {
-	INIT_VNET_INET(ifp->if_vnet);
 	struct igmp_ifinfo *igi;
 
 	IGMP_LOCK_ASSERT();
@@ -661,7 +671,6 @@ igmp_domifdetach(struct ifnet *ifp)
 static void
 igi_delete_locked(const struct ifnet *ifp)
 {
-	INIT_VNET_INET(ifp->if_vnet);
 	struct igmp_ifinfo *igi, *tigi;
 
 	CTR3(KTR_IGMPV3, "%s: freeing igmp_ifinfo for ifp %p(%s)",
@@ -702,7 +711,6 @@ static int
 igmp_input_v1_query(struct ifnet *ifp, const struct ip *ip,
     const struct igmp *igmp)
 {
-	INIT_VNET_INET(ifp->if_vnet);
 	struct ifmultiaddr	*ifma;
 	struct igmp_ifinfo	*igi;
 	struct in_multi		*inm;
@@ -788,7 +796,6 @@ static int
 igmp_input_v2_query(struct ifnet *ifp, const struct ip *ip,
     const struct igmp *igmp)
 {
-	INIT_VNET_INET(ifp->if_vnet);
 	struct ifmultiaddr	*ifma;
 	struct igmp_ifinfo	*igi;
 	struct in_multi		*inm;
@@ -893,7 +900,6 @@ out_locked:
 static void
 igmp_v2_update_group(struct in_multi *inm, const int timer)
 {
-	INIT_VNET_INET(curvnet);
 
 	CTR4(KTR_IGMPV3, "%s: %s/%s timer=%d", __func__,
 	    inet_ntoa(inm->inm_addr), inm->inm_ifp->if_xname, timer);
@@ -941,7 +947,6 @@ static int
 igmp_input_v3_query(struct ifnet *ifp, const struct ip *ip,
     /*const*/ struct igmpv3 *igmpv3)
 {
-	INIT_VNET_INET(ifp->if_vnet);
 	struct igmp_ifinfo	*igi;
 	struct in_multi		*inm;
 	int			 is_general_query;
@@ -1106,7 +1111,6 @@ static int
 igmp_input_v3_group_query(struct in_multi *inm, struct igmp_ifinfo *igi,
     int timer, /*const*/ struct igmpv3 *igmpv3)
 {
-	INIT_VNET_INET(curvnet);
 	int			 retval;
 	uint16_t		 nsrc;
 
@@ -1209,7 +1213,6 @@ static int
 igmp_input_v1_report(struct ifnet *ifp, /*const*/ struct ip *ip,
     /*const*/ struct igmp *igmp)
 {
-	INIT_VNET_INET(ifp->if_vnet);
 	struct in_ifaddr *ia;
 	struct in_multi *inm;
 
@@ -1318,7 +1321,6 @@ static int
 igmp_input_v2_report(struct ifnet *ifp, /*const*/ struct ip *ip,
     /*const*/ struct igmp *igmp)
 {
-	INIT_VNET_INET(ifp->if_vnet);
 	struct in_ifaddr *ia;
 	struct in_multi *inm;
 
@@ -1436,7 +1438,6 @@ igmp_input(struct mbuf *m, int off)
 	CTR3(KTR_IGMPV3, "%s: called w/mbuf (%p,%d)", __func__, m, off);
 
 	ifp = m->m_pkthdr.rcvif;
-	INIT_VNET_INET(ifp->if_vnet);
 
 	IGMPSTAT_INC(igps_rcv_total);
 
@@ -1633,7 +1634,6 @@ igmp_fasttimo(void)
 static void
 igmp_fasttimo_vnet(void)
 {
-	INIT_VNET_INET(curvnet);
 	struct ifqueue		 scq;	/* State-change packets */
 	struct ifqueue		 qrq;	/* Query response packets */
 	struct ifnet		*ifp;
@@ -1756,7 +1756,6 @@ out_locked:
 static void
 igmp_v1v2_process_group_timer(struct in_multi *inm, const int version)
 {
-	INIT_VNET_INET(curvnet);
 	int report_timer_expired;
 
 	IN_MULTI_LOCK_ASSERT();
@@ -1805,7 +1804,6 @@ igmp_v3_process_group_timers(struct igmp_ifinfo *igi,
     struct ifqueue *qrq, struct ifqueue *scq,
     struct in_multi *inm, const int uri_fasthz)
 {
-	INIT_VNET_INET(curvnet);
 	int query_response_timer_expired;
 	int state_change_retransmit_timer_expired;
 
@@ -2083,7 +2081,6 @@ igmp_v3_cancel_link_timers(struct igmp_ifinfo *igi)
 static void
 igmp_v1v2_process_querier_timers(struct igmp_ifinfo *igi)
 {
-	INIT_VNET_INET(curvnet);
 
 	IGMP_LOCK_ASSERT();
 
@@ -2177,7 +2174,6 @@ igmp_slowtimo(void)
 static void
 igmp_slowtimo_vnet(void)
 {
-	INIT_VNET_INET(curvnet);
 	struct igmp_ifinfo *igi;
 
 	IGMP_LOCK();
@@ -2342,7 +2338,6 @@ out_locked:
 static int
 igmp_initial_join(struct in_multi *inm, struct igmp_ifinfo *igi)
 {
-	INIT_VNET_INET(curvnet);
 	struct ifnet		*ifp;
 	struct ifqueue		*ifq;
 	int			 error, retval, syncstates;
@@ -2471,7 +2466,6 @@ igmp_initial_join(struct in_multi *inm, struct igmp_ifinfo *igi)
 static int
 igmp_handle_state_change(struct in_multi *inm, struct igmp_ifinfo *igi)
 {
-	INIT_VNET_INET(curvnet);
 	struct ifnet		*ifp;
 	int			 retval;
 
@@ -2531,7 +2525,6 @@ igmp_handle_state_change(struct in_multi *inm, struct igmp_ifinfo *igi)
 static void
 igmp_final_leave(struct in_multi *inm, struct igmp_ifinfo *igi)
 {
-	INIT_VNET_INET(curvnet);
 	int syncstates;
 
 	syncstates = 1;
@@ -3324,7 +3317,6 @@ igmp_v3_merge_state_changes(struct in_multi *inm, struct ifqueue *ifscq)
 static void
 igmp_v3_dispatch_general_query(struct igmp_ifinfo *igi)
 {
-	INIT_VNET_INET(curvnet);
 	struct ifmultiaddr	*ifma, *tifma;
 	struct ifnet		*ifp;
 	struct in_multi		*inm;
@@ -3412,8 +3404,6 @@ igmp_intr(struct mbuf *m)
 	 * unique to each VIMAGE and must be retrieved.
 	 */
 	CURVNET_SET((struct vnet *)(m->m_pkthdr.header));
-	INIT_VNET_NET(curvnet);
-	INIT_VNET_INET(curvnet);
 	ifindex = igmp_restore_context(m);
 
 	/*
@@ -3495,7 +3485,6 @@ out:
 static struct mbuf *
 igmp_v3_encap_report(struct ifnet *ifp, struct mbuf *m)
 {
-	INIT_VNET_INET(curvnet);
 	struct igmp_report	*igmp;
 	struct ip		*ip;
 	int			 hdrlen, igmpreclen;
@@ -3621,30 +3610,14 @@ igmp_sysuninit(void)
 static int
 vnet_igmp_iattach(const void *unused __unused)
 {
-	INIT_VNET_INET(curvnet);
 
 	CTR1(KTR_IGMPV3, "%s: initializing", __func__);
 
 	LIST_INIT(&V_igi_head);
 
-	V_current_state_timers_running = 0;
-	V_state_change_timers_running = 0;
-	V_interface_timers_running = 0;
-
 	/*
 	 * Initialize sysctls to default values.
 	 */
-	V_igmp_recvifkludge = 1;
-	V_igmp_sendra = 1;
-	V_igmp_sendlocal = 1;
-	V_igmp_v1enable = 1;
-	V_igmp_v2enable = 1;
-	V_igmp_legacysupp = 0;
-	V_igmp_default_version = IGMP_VERSION_3;
-	V_igmp_gsrdelay.tv_sec = 10;
-	V_igmp_gsrdelay.tv_usec = 0;
-
-	memset(&V_igmpstat, 0, sizeof(struct igmpstat));
 	V_igmpstat.igps_version = IGPS_VERSION_3;
 	V_igmpstat.igps_len = sizeof(struct igmpstat);
 
@@ -3654,9 +3627,6 @@ vnet_igmp_iattach(const void *unused __unused)
 static int
 vnet_igmp_idetach(const void *unused __unused)
 {
-#ifdef INVARIANTS
-	INIT_VNET_INET(curvnet);
-#endif
 
 	CTR1(KTR_IGMPV3, "%s: tearing down", __func__);
 
@@ -3666,7 +3636,7 @@ vnet_igmp_idetach(const void *unused __unused)
 	return (0);
 }
 
-#ifndef VIMAGE_GLOBALS
+#ifdef VIMAGE
 static vnet_modinfo_t vnet_igmp_modinfo = {
 	.vmi_id		= VNET_MOD_IGMP,
 	.vmi_name	= "igmp",
@@ -3683,14 +3653,14 @@ igmp_modevent(module_t mod, int type, void *unused __unused)
     switch (type) {
     case MOD_LOAD:
 	igmp_sysinit();
-#ifndef VIMAGE_GLOBALS
+#ifdef VIMAGE
 	vnet_mod_register(&vnet_igmp_modinfo);
 #else
 	vnet_igmp_iattach(NULL);
 #endif
 	break;
     case MOD_UNLOAD:
-#ifndef VIMAGE_GLOBALS
+#ifdef VIMAGE
 	vnet_mod_deregister(&vnet_igmp_modinfo);
 #else
 	vnet_igmp_idetach(NULL);