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)

4 files changed, 0 insertions, 11 deletions

diff --git a/sys/compat/linprocfs/linprocfs.c b/sys/compat/linprocfs/linprocfs.c
index ed68b1a..5bca381 100644
--- a/sys/compat/linprocfs/linprocfs.c
+++ b/sys/compat/linprocfs/linprocfs.c
@@ -1078,7 +1078,6 @@ linprocfs_doprocmaps(PFS_FILL_ARGS)
 static int
 linprocfs_donetdev(PFS_FILL_ARGS)
 {
-	INIT_VNET_NET(TD_TO_VNET(td));
 	char ifname[16]; /* XXX LINUX_IFNAMSIZ */
 	struct ifnet *ifp;
 
diff --git a/sys/compat/linux/linux_ioctl.c b/sys/compat/linux/linux_ioctl.c
index 7d11b98..a8b0945 100644
--- a/sys/compat/linux/linux_ioctl.c
+++ b/sys/compat/linux/linux_ioctl.c
@@ -2059,7 +2059,6 @@ linux_ioctl_console(struct thread *td, struct linux_ioctl_args *args)
 int
 linux_ifname(struct ifnet *ifp, char *buffer, size_t buflen)
 {
-	INIT_VNET_NET(ifp->if_vnet);
 	struct ifnet *ifscan;
 	int ethno;
 
@@ -2093,7 +2092,6 @@ linux_ifname(struct ifnet *ifp, char *buffer, size_t buflen)
 static struct ifnet *
 ifname_linux_to_bsd(struct thread *td, const char *lxname, char *bsdname)
 {
-	INIT_VNET_NET(TD_TO_VNET(td));
 	struct ifnet *ifp;
 	int len, unit;
 	char *ep;
@@ -2134,7 +2132,6 @@ ifname_linux_to_bsd(struct thread *td, const char *lxname, char *bsdname)
 static int
 linux_ifconf(struct thread *td, struct ifconf *uifc)
 {
-	INIT_VNET_NET(TD_TO_VNET(td));
 #ifdef COMPAT_LINUX32
 	struct l_ifconf ifc;
 #else
diff --git a/sys/compat/linux/linux_socket.c b/sys/compat/linux/linux_socket.c
index 45a1d53..0c48b91 100644
--- a/sys/compat/linux/linux_socket.c
+++ b/sys/compat/linux/linux_socket.c
@@ -60,7 +60,6 @@ __FBSDID("$FreeBSD$");
 #include <netinet/ip6.h>
 #include <netinet6/ip6_var.h>
 #include <netinet6/in6_var.h>
-#include <netinet6/vinet6.h>
 #endif
 
 #ifdef COMPAT_LINUX32
@@ -599,11 +598,6 @@ struct linux_socket_args {
 static int
 linux_socket(struct thread *td, struct linux_socket_args *args)
 {
-#ifdef INET6
-#ifndef KLD_MODULE
-	INIT_VNET_INET6(curvnet);
-#endif
-#endif
 	struct socket_args /* {
 		int domain;
 		int type;
diff --git a/sys/compat/svr4/svr4_sockio.c b/sys/compat/svr4/svr4_sockio.c
index 6ed4e69..ec62f71 100644
--- a/sys/compat/svr4/svr4_sockio.c
+++ b/sys/compat/svr4/svr4_sockio.c
@@ -89,7 +89,6 @@ svr4_sock_ioctl(fp, td, retval, fd, cmd, data)
 	switch (cmd) {
 	case SVR4_SIOCGIFNUM:
 		{
-			INIT_VNET_NET(curvnet);
 			struct ifnet *ifp;
 			struct ifaddr *ifa;
 			int ifnum = 0;