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, 17 insertions, 49 deletions

diff --git a/sys/netinet6/mld6.c b/sys/netinet6/mld6.c
index 61fff11..98c9021 100644
--- a/sys/netinet6/mld6.c
+++ b/sys/netinet6/mld6.c
@@ -94,8 +94,6 @@ __FBSDID("$FreeBSD$");
 #include <netinet/icmp6.h>
 #include <netinet6/mld6.h>
 #include <netinet6/mld6_var.h>
-#include <netinet/vinet.h>
-#include <netinet6/vinet6.h>
 
 #include <security/mac/mac_framework.h>
 
@@ -207,13 +205,17 @@ MALLOC_DEFINE(M_MLD, "mld", "mld state");
 /*
  * VIMAGE-wide globals.
  */
-#ifdef VIMAGE_GLOBALS
-struct timeval			 mld_gsrdelay;
-LIST_HEAD(, mld_ifinfo)		 mli_head;
-int				 interface_timers_running6;
-int				 state_change_timers_running6;
-int				 current_state_timers_running6;
-#endif /* VIMAGE_GLOBALS */
+static VNET_DEFINE(struct timeval, mld_gsrdelay) = {10, 0};
+static VNET_DEFINE(LIST_HEAD(, mld_ifinfo), mli_head);
+static VNET_DEFINE(int, interface_timers_running6);
+static VNET_DEFINE(int, state_change_timers_running6);
+static VNET_DEFINE(int, current_state_timers_running6);
+
+#define	V_mld_gsrdelay			VNET_GET(mld_gsrdelay)
+#define	V_mli_head			VNET_GET(mli_head)
+#define	V_interface_timers_running6	VNET_GET(interface_timers_running6)
+#define	V_state_change_timers_running6	VNET_GET(state_change_timers_running6)
+#define	V_current_state_timers_running6	VNET_GET(current_state_timers_running6)
 
 SYSCTL_DECL(_net_inet6);	/* Note: Not in any common header. */
 
@@ -223,9 +225,9 @@ SYSCTL_NODE(_net_inet6, OID_AUTO, mld, CTLFLAG_RW, 0,
 /*
  * Virtualized sysctls.
  */
-SYSCTL_V_PROC(V_NET, vnet_inet6, _net_inet6_mld, OID_AUTO, gsrdelay,
-    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, mld_gsrdelay.tv_sec, 0,
-    sysctl_mld_gsr, "I",
+SYSCTL_VNET_PROC(_net_inet6_mld, OID_AUTO, gsrdelay,
+    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
+    &VNET_NAME(mld_gsrdelay.tv_sec), 0, sysctl_mld_gsr, "I",
     "Rate limit for MLDv2 Group-and-Source queries in seconds");
 
 /*
@@ -308,7 +310,6 @@ mld_restore_context(struct mbuf *m)
 static int
 sysctl_mld_gsr(SYSCTL_HANDLER_ARGS)
 {
-	INIT_VNET_INET6(curvnet);
 	int error;
 	int i;
 
@@ -349,8 +350,6 @@ out_locked:
 static int
 sysctl_mld_ifinfo(SYSCTL_HANDLER_ARGS)
 {
-	INIT_VNET_NET(curvnet);
-	INIT_VNET_INET6(curvnet);
 	int			*name;
 	int			 error;
 	u_int			 namelen;
@@ -479,7 +478,6 @@ mld_domifattach(struct ifnet *ifp)
 static struct mld_ifinfo *
 mli_alloc_locked(/*const*/ struct ifnet *ifp)
 {
-	INIT_VNET_INET6(ifp->if_vnet);
 	struct mld_ifinfo *mli;
 
 	MLD_LOCK_ASSERT();
@@ -582,7 +580,6 @@ mld_domifdetach(struct ifnet *ifp)
 static void
 mli_delete_locked(const struct ifnet *ifp)
 {
-	INIT_VNET_INET6(ifp->if_vnet);
 	struct mld_ifinfo *mli, *tmli;
 
 	CTR3(KTR_MLD, "%s: freeing mld_ifinfo for ifp %p(%s)",
@@ -747,7 +744,6 @@ mld_v1_input_query(struct ifnet *ifp, const struct ip6_hdr *ip6,
 static void
 mld_v1_update_group(struct in6_multi *inm, const int timer)
 {
-	INIT_VNET_INET6(curvnet);
 #ifdef KTR
 	char			 ip6tbuf[INET6_ADDRSTRLEN];
 #endif
@@ -801,7 +797,6 @@ static int
 mld_v2_input_query(struct ifnet *ifp, const struct ip6_hdr *ip6,
     struct mbuf *m, const int off, const int icmp6len)
 {
-	INIT_VNET_INET6(curvnet);
 	struct mld_ifinfo	*mli;
 	struct mldv2_query	*mld;
 	struct in6_multi	*inm;
@@ -980,7 +975,6 @@ static int
 mld_v2_process_group_query(struct in6_multi *inm, struct mld_ifinfo *mli,
     int timer, struct mbuf *m0, const int off)
 {
-	INIT_VNET_INET6(curvnet);
 	struct mldv2_query	*mld;
 	int			 retval;
 	uint16_t		 nsrc;
@@ -1252,7 +1246,6 @@ mld_input(struct mbuf *m, int off, int icmp6len)
 	CTR3(KTR_MLD, "%s: called w/mbuf (%p,%d)", __func__, m, off);
 
 	ifp = m->m_pkthdr.rcvif;
-	INIT_VNET_INET6(ifp->if_vnet);
 
 	ip6 = mtod(m, struct ip6_hdr *);
 
@@ -1330,7 +1323,6 @@ mld_fasttimo(void)
 static void
 mld_fasttimo_vnet(void)
 {
-	INIT_VNET_INET6(curvnet);
 	struct ifqueue		 scq;	/* State-change packets */
 	struct ifqueue		 qrq;	/* Query response packets */
 	struct ifnet		*ifp;
@@ -1458,7 +1450,6 @@ out_locked:
 static void
 mld_v1_process_group_timer(struct in6_multi *inm, const int version)
 {
-	INIT_VNET_INET6(curvnet);
 	int report_timer_expired;
 
 	IN6_MULTI_LOCK_ASSERT();
@@ -1505,7 +1496,6 @@ mld_v2_process_group_timers(struct mld_ifinfo *mli,
     struct ifqueue *qrq, struct ifqueue *scq,
     struct in6_multi *inm, const int uri_fasthz)
 {
-	INIT_VNET_INET6(curvnet);
 	int query_response_timer_expired;
 	int state_change_retransmit_timer_expired;
 #ifdef KTR
@@ -1654,7 +1644,6 @@ mld_set_version(struct mld_ifinfo *mli, const int version)
 static void
 mld_v2_cancel_link_timers(struct mld_ifinfo *mli)
 {
-	INIT_VNET_INET6(curvnet);
 	struct ifmultiaddr	*ifma;
 	struct ifnet		*ifp;
 	struct in6_multi		*inm;
@@ -1747,7 +1736,6 @@ mld_slowtimo(void)
 static void
 mld_slowtimo_vnet(void)
 {
-	INIT_VNET_INET6(curvnet);
 	struct mld_ifinfo *mli;
 
 	MLD_LOCK();
@@ -1951,7 +1939,6 @@ static int
 mld_initial_join(struct in6_multi *inm, struct mld_ifinfo *mli,
     const int delay)
 {
-	INIT_VNET_INET6(curvnet);
 	struct ifnet		*ifp;
 	struct ifqueue		*ifq;
 	int			 error, retval, syncstates;
@@ -2100,7 +2087,6 @@ mld_initial_join(struct in6_multi *inm, struct mld_ifinfo *mli,
 static int
 mld_handle_state_change(struct in6_multi *inm, struct mld_ifinfo *mli)
 {
-	INIT_VNET_INET6(curvnet);
 	struct ifnet		*ifp;
 	int			 retval;
 #ifdef KTR
@@ -2164,7 +2150,6 @@ mld_handle_state_change(struct in6_multi *inm, struct mld_ifinfo *mli)
 static void
 mld_final_leave(struct in6_multi *inm, struct mld_ifinfo *mli)
 {
-	INIT_VNET_INET6(curvnet);
 	int syncstates;
 #ifdef KTR
 	char ip6tbuf[INET6_ADDRSTRLEN];
@@ -2947,7 +2932,6 @@ mld_v2_merge_state_changes(struct in6_multi *inm, struct ifqueue *ifscq)
 static void
 mld_v2_dispatch_general_query(struct mld_ifinfo *mli)
 {
-	INIT_VNET_INET6(curvnet);
 	struct ifmultiaddr	*ifma, *tifma;
 	struct ifnet		*ifp;
 	struct in6_multi	*inm;
@@ -3036,8 +3020,6 @@ mld_dispatch_packet(struct mbuf *m)
 	 * indexes to guard against interface detach, they are
 	 * unique to each VIMAGE and must be retrieved.
 	 */
-	INIT_VNET_NET(curvnet);
-	INIT_VNET_INET6(curvnet);
 	ifindex = mld_restore_context(m);
 
 	/*
@@ -3247,31 +3229,17 @@ mld_sysuninit(void)
 static int
 vnet_mld_iattach(const void *unused __unused)
 {
-	INIT_VNET_INET6(curvnet);
 
 	CTR1(KTR_MLD, "%s: initializing", __func__);
 
 	LIST_INIT(&V_mli_head);
 
-	V_current_state_timers_running6 = 0;
-	V_interface_timers_running6 = 0;
-	V_state_change_timers_running6 = 0;
-
-	/*
-	 * Initialize sysctls to default values.
-	 */
-	V_mld_gsrdelay.tv_sec = 10;
-	V_mld_gsrdelay.tv_usec = 0;
-
 	return (0);
 }
 
 static int
 vnet_mld_idetach(const void *unused __unused)
 {
-#ifdef INVARIANTS
-	INIT_VNET_INET6(curvnet);
-#endif
 
 	CTR1(KTR_MLD, "%s: tearing down", __func__);
 
@@ -3281,7 +3249,7 @@ vnet_mld_idetach(const void *unused __unused)
 	return (0);
 }
 
-#ifndef VIMAGE_GLOBALS
+#ifdef VIMAGE
 static vnet_modinfo_t vnet_mld_modinfo = {
 	.vmi_id		= VNET_MOD_MLD,
 	.vmi_name	= "mld",
@@ -3298,14 +3266,14 @@ mld_modevent(module_t mod, int type, void *unused __unused)
     switch (type) {
     case MOD_LOAD:
 	mld_sysinit();
-#ifndef VIMAGE_GLOBALS
+#ifdef VIMAGE
 	vnet_mod_register(&vnet_mld_modinfo);
 #else
 	vnet_mld_iattach(NULL);
 #endif
 	break;
     case MOD_UNLOAD:
-#ifndef VIMAGE_GLOBALS
+#ifdef VIMAGE
 	vnet_mod_deregister(&vnet_mld_modinfo);
 #else
 	vnet_mld_idetach(NULL);