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, 0 insertions, 17 deletions

diff --git a/sys/netinet/in_mcast.c b/sys/netinet/in_mcast.c
index 5c299af..6efa7d8 100644
--- a/sys/netinet/in_mcast.c
+++ b/sys/netinet/in_mcast.c
@@ -60,7 +60,6 @@ __FBSDID("$FreeBSD$");
 #include <netinet/in_var.h>
 #include <netinet/ip_var.h>
 #include <netinet/igmp_var.h>
-#include <netinet/vinet.h>
 
 #ifndef KTR_IGMPV3
 #define KTR_IGMPV3 KTR_INET
@@ -84,10 +83,6 @@ static MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "IPv4 multicast options");
 static MALLOC_DEFINE(M_IPMSOURCE, "ip_msource",
     "IPv4 multicast IGMP-layer source filter");
 
-#ifdef VIMAGE_GLOBALS
-struct in_multihead in_multihead;	/* XXX now unused; retain for ABI */
-#endif
-
 /*
  * Locking:
  * - Lock order is: Giant, INP_WLOCK, IN_MULTI_LOCK, IGMP_LOCK, IF_ADDR_LOCK.
@@ -1295,8 +1290,6 @@ in_delmulti(struct in_multi *inm)
 static int
 inp_block_unblock_source(struct inpcb *inp, struct sockopt *sopt)
 {
-	INIT_VNET_NET(curvnet);
-	INIT_VNET_INET(curvnet);
 	struct group_source_req		 gsr;
 	sockunion_t			*gsa, *ssa;
 	struct ifnet			*ifp;
@@ -1560,7 +1553,6 @@ inp_freemoptions(struct ip_moptions *imo)
 static int
 inp_get_source_filters(struct inpcb *inp, struct sockopt *sopt)
 {
-	INIT_VNET_NET(curvnet);
 	struct __msfilterreq	 msfr;
 	sockunion_t		*gsa;
 	struct ifnet		*ifp;
@@ -1678,7 +1670,6 @@ inp_get_source_filters(struct inpcb *inp, struct sockopt *sopt)
 int
 inp_getmoptions(struct inpcb *inp, struct sockopt *sopt)
 {
-	INIT_VNET_INET(curvnet);
 	struct ip_mreqn		 mreqn;
 	struct ip_moptions	*imo;
 	struct ifnet		*ifp;
@@ -1809,7 +1800,6 @@ static struct ifnet *
 inp_lookup_mcast_ifp(const struct inpcb *inp,
     const struct sockaddr_in *gsin, const struct in_addr ina)
 {
-	INIT_VNET_INET(curvnet);
 	struct ifnet *ifp;
 
 	KASSERT(gsin->sin_family == AF_INET, ("%s: not AF_INET", __func__));
@@ -1856,7 +1846,6 @@ inp_lookup_mcast_ifp(const struct inpcb *inp,
 static int
 inp_join_group(struct inpcb *inp, struct sockopt *sopt)
 {
-	INIT_VNET_NET(curvnet);
 	struct group_source_req		 gsr;
 	sockunion_t			*gsa, *ssa;
 	struct ifnet			*ifp;
@@ -2097,8 +2086,6 @@ out_inp_locked:
 static int
 inp_leave_group(struct inpcb *inp, struct sockopt *sopt)
 {
-	INIT_VNET_NET(curvnet);
-	INIT_VNET_INET(curvnet);
 	struct group_source_req		 gsr;
 	struct ip_mreq_source		 mreqs;
 	sockunion_t			*gsa, *ssa;
@@ -2308,8 +2295,6 @@ out_inp_locked:
 static int
 inp_set_multicast_if(struct inpcb *inp, struct sockopt *sopt)
 {
-	INIT_VNET_NET(curvnet);
-	INIT_VNET_INET(curvnet);
 	struct in_addr		 addr;
 	struct ip_mreqn		 mreqn;
 	struct ifnet		*ifp;
@@ -2376,7 +2361,6 @@ inp_set_multicast_if(struct inpcb *inp, struct sockopt *sopt)
 static int
 inp_set_source_filters(struct inpcb *inp, struct sockopt *sopt)
 {
-	INIT_VNET_NET(curvnet);
 	struct __msfilterreq	 msfr;
 	sockunion_t		*gsa;
 	struct ifnet		*ifp;
@@ -2699,7 +2683,6 @@ inp_setmoptions(struct inpcb *inp, struct sockopt *sopt)
 static int
 sysctl_ip_mcast_filters(SYSCTL_HANDLER_ARGS)
 {
-	INIT_VNET_NET(curvnet);
 	struct in_addr			 src, group;
 	struct ifnet			*ifp;
 	struct ifmultiaddr		*ifma;