Add the mlockall() and munlockall() system calls.

 - All those diffs to syscalls.master for each architecture *are*
   necessary. This needed clarification; the stub code generation for
   mlockall() was disabled, which would prevent applications from
   linking to this API (suggested by mux)
 - Giant has been quoshed. It is no longer held by the code, as
   the required locking has been pushed down within vm_map.c.
 - Callers must specify VM_MAP_WIRE_HOLESOK or VM_MAP_WIRE_NOHOLES
   to express their intention explicitly.
 - Inspected at the vmstat, top and vm pager sysctl stats level.
   Paging-in activity is occurring correctly, using a test harness.
 - The RES size for a process may appear to be greater than its SIZE.
   This is believed to be due to mappings of the same shared library
   page being wired twice. Further exploration is needed.
 - Believed to back out of allocations and locks correctly
   (tested with WITNESS, MUTEX_PROFILING, INVARIANTS and DIAGNOSTIC).

PR:             kern/43426, standards/54223
Reviewed by:    jake, alc
Approved by:    jake (mentor)
MFC after:	2 weeks

17 files changed, 180 insertions, 37 deletions

diff --git a/lib/libc/alpha/sys/Makefile.inc b/lib/libc/alpha/sys/Makefile.inc
index 4039813..d0b21ed 100644
--- a/lib/libc/alpha/sys/Makefile.inc
+++ b/lib/libc/alpha/sys/Makefile.inc
@@ -5,7 +5,7 @@ MDASM+=	Ovfork.S brk.S cerror.S exect.S fork.S pipe.S ptrace.S \
 
 # Don't generate default code for these syscalls:
 NOASM=	break.o exit.o ftruncate.o getdomainname.o getlogin.o \
-	lseek.o mlockall.o mmap.o munlockall.o openbsd_poll.o pread.o \
+	lseek.o mmap.o openbsd_poll.o pread.o \
 	pwrite.o setdomainname.o sstk.o truncate.o uname.o vfork.o yield.o
 
 PSEUDO=	_getlogin.o _exit.o
diff --git a/lib/libc/amd64/sys/Makefile.inc b/lib/libc/amd64/sys/Makefile.inc
index adfa8485..897ed4f 100644
--- a/lib/libc/amd64/sys/Makefile.inc
+++ b/lib/libc/amd64/sys/Makefile.inc
@@ -6,7 +6,7 @@ MDASM=	vfork.S brk.S cerror.S exect.S pipe.S ptrace.S reboot.S sbrk.S \
 
 # Don't generate default code for these syscalls:
 NOASM=	break.o exit.o ftruncate.o getdomainname.o getlogin.o \
-	lseek.o mlockall.o mmap.o munlockall.o openbsd_poll.o pread.o \
+	lseek.o mmap.o openbsd_poll.o pread.o \
 	pwrite.o setdomainname.o sstk.o truncate.o uname.o vfork.o yield.o
 
 PSEUDO=	_getlogin.o _exit.o
diff --git a/lib/libc/i386/sys/Makefile.inc b/lib/libc/i386/sys/Makefile.inc
index d928ea9..ad76609 100644
--- a/lib/libc/i386/sys/Makefile.inc
+++ b/lib/libc/i386/sys/Makefile.inc
@@ -9,7 +9,7 @@ MDASM=	Ovfork.S brk.S cerror.S exect.S pipe.S ptrace.S reboot.S sbrk.S \
 
 # Don't generate default code for these syscalls:
 NOASM=	break.o exit.o ftruncate.o getdomainname.o getlogin.o \
-	lseek.o mlockall.o mmap.o munlockall.o openbsd_poll.o pread.o \
+	lseek.o mmap.o openbsd_poll.o pread.o \
 	pwrite.o setdomainname.o sstk.o truncate.o uname.o vfork.o yield.o
 
 PSEUDO=	_getlogin.o _exit.o
diff --git a/lib/libc/ia64/sys/Makefile.inc b/lib/libc/ia64/sys/Makefile.inc
index 6306763..dacd2f9 100644
--- a/lib/libc/ia64/sys/Makefile.inc
+++ b/lib/libc/ia64/sys/Makefile.inc
@@ -5,7 +5,7 @@ MDASM+=	Ovfork.S brk.S cerror.S exect.S fork.S getcontext.S pipe.S ptrace.S \
 
 # Don't generate default code for these syscalls:
 NOASM=	break.o exit.o ftruncate.o getdomainname.o getlogin.o \
-	lseek.o mlockall.o mmap.o munlockall.o openbsd_poll.o pread.o \
+	lseek.o mmap.o openbsd_poll.o pread.o \
 	pwrite.o setdomainname.o sstk.o truncate.o uname.o vfork.o yield.o
 
 PSEUDO=	_getlogin.o _exit.o
diff --git a/lib/libc/powerpc/sys/Makefile.inc b/lib/libc/powerpc/sys/Makefile.inc
index 3718c1a..84579ae 100644
--- a/lib/libc/powerpc/sys/Makefile.inc
+++ b/lib/libc/powerpc/sys/Makefile.inc
@@ -4,7 +4,7 @@ MDASM+=	brk.S cerror.S exect.S pipe.S ptrace.S sbrk.S setlogin.S
 
 # Don't generate default code for these syscalls:
 NOASM=	break.o exit.o ftruncate.o getdomainname.o getlogin.o \
-	lseek.o mlockall.o mmap.o munlockall.o openbsd_poll.o pread.o \
+	lseek.o mmap.o openbsd_poll.o pread.o \
 	pwrite.o setdomainname.o sstk.o truncate.o uname.o yield.o
 
 PSEUDO=	_getlogin.o _exit.o
diff --git a/lib/libc/sparc64/sys/Makefile.inc b/lib/libc/sparc64/sys/Makefile.inc
index 67d9acd..f677df1 100644
--- a/lib/libc/sparc64/sys/Makefile.inc
+++ b/lib/libc/sparc64/sys/Makefile.inc
@@ -16,7 +16,7 @@ MDASM+=	brk.S cerror.S exect.S pipe.S ptrace.S sbrk.S setlogin.S sigaction.S
 
 # Don't generate default code for these syscalls:
 NOASM=	break.o exit.o ftruncate.o getdomainname.o getlogin.o \
-	lseek.o mlockall.o mmap.o munlockall.o openbsd_poll.o pread.o \
+	lseek.o mmap.o openbsd_poll.o pread.o \
 	pwrite.o setdomainname.o sstk.o truncate.o uname.o yield.o
 
 PSEUDO=	_getlogin.o _exit.o
diff --git a/lib/libc/sys/Makefile.inc b/lib/libc/sys/Makefile.inc
index ae536d5..d66bd7f 100644
--- a/lib/libc/sys/Makefile.inc
+++ b/lib/libc/sys/Makefile.inc
@@ -69,8 +69,8 @@ MAN+=	_exit.2 accept.2 access.2 acct.2 adjtime.2 \
 	kldfind.2 kldfirstmod.2 kldload.2 kldnext.2 kldstat.2 kldsym.2 \
 	kldunload.2 kqueue.2 kse.2 ktrace.2 link.2 lio_listio.2 listen.2 \
 	lseek.2 \
-	madvise.2 mincore.2 minherit.2 mkdir.2 mkfifo.2 mknod.2 mlock.2 mmap.2 \
-	modfind.2 modnext.2 modstat.2 mount.2 \
+	madvise.2 mincore.2 minherit.2 mkdir.2 mkfifo.2 mknod.2 mlock.2 \
+	mlockall.2 mmap.2 modfind.2 modnext.2 modstat.2 mount.2 \
 	mprotect.2 msync.2 munmap.2 nanosleep.2 ntp_adjtime.2 ntp_gettime.2 \
 	nfssvc.2 open.2 pathconf.2 pipe.2 poll.2 profil.2 ptrace.2 quotactl.2 \
 	read.2 readlink.2 reboot.2 recv.2 rename.2 revoke.2 rfork.2 rmdir.2 \
@@ -121,6 +121,7 @@ MLINKS+=kse.2 kse_create.2 kse.2 kse_exit.2 kse.2 kse_release.2 \
 	kse.2 kse_wakeup.2 kse.2 kse_thr_interrupt.2
 MLINKS+=madvise.2 posix_madvise.2
 MLINKS+=mlock.2 munlock.2
+MLINKS+=mlockall.2 munlockall.2
 MLINKS+=modnext.2 modfnext.2
 MLINKS+=mount.2 unmount.2
 MLINKS+=pathconf.2 fpathconf.2
diff --git a/sys/kern/link_elf.c b/sys/kern/link_elf.c
index cf7117a..f05cab1 100644
--- a/sys/kern/link_elf.c
+++ b/sys/kern/link_elf.c
@@ -745,7 +745,7 @@ link_elf_load_file(linker_class_t cls, const char* filename,
 	vm_map_wire(kernel_map,
 		    (vm_offset_t) segbase,
 		    (vm_offset_t) segbase + segs[i]->p_memsz,
-		    FALSE);
+		    VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
 #endif
     }
 
diff --git a/sys/kern/link_elf_obj.c b/sys/kern/link_elf_obj.c
index cf7117a..f05cab1 100644
--- a/sys/kern/link_elf_obj.c
+++ b/sys/kern/link_elf_obj.c
@@ -745,7 +745,7 @@ link_elf_load_file(linker_class_t cls, const char* filename,
 	vm_map_wire(kernel_map,
 		    (vm_offset_t) segbase,
 		    (vm_offset_t) segbase + segs[i]->p_memsz,
-		    FALSE);
+		    VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
 #endif
     }
 
diff --git a/sys/sys/mman.h b/sys/sys/mman.h
index ec058d8..09162ec 100644
--- a/sys/sys/mman.h
+++ b/sys/sys/mman.h
@@ -188,6 +188,8 @@ int	munmap(void *, size_t);
 int	posix_madvise(void *, size_t, int);
 #endif
 #if __POSIX_VISIBLE >= 199309
+int	mlockall(int);
+int	munlockall(void);
 int	shm_open(const char *, int, mode_t);
 int	shm_unlink(const char *);
 #endif
diff --git a/sys/vm/vm_contig.c b/sys/vm/vm_contig.c
index a4dca9b..9e6f57d 100644
--- a/sys/vm/vm_contig.c
+++ b/sys/vm/vm_contig.c
@@ -266,7 +266,8 @@ again1:
 			tmp_addr += PAGE_SIZE;
 		}
 		VM_OBJECT_UNLOCK(kernel_object);
-		vm_map_wire(map, addr, addr + size, FALSE);
+		vm_map_wire(map, addr, addr + size,
+		    VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
 
 		splx(s);
 		return ((void *)addr);
diff --git a/sys/vm/vm_glue.c b/sys/vm/vm_glue.c
index d0f6bf2..5d0744b 100644
--- a/sys/vm/vm_glue.c
+++ b/sys/vm/vm_glue.c
@@ -189,7 +189,8 @@ vslock(addr, len)
 {
 
 	vm_map_wire(&curproc->p_vmspace->vm_map, trunc_page((vm_offset_t)addr),
-	    round_page((vm_offset_t)addr + len), FALSE);
+	    round_page((vm_offset_t)addr + len),
+	    VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
 }
 
 /*
@@ -203,7 +204,8 @@ vsunlock(addr, len)
 
 	vm_map_unwire(&curproc->p_vmspace->vm_map,
 	    trunc_page((vm_offset_t)addr),
-	    round_page((vm_offset_t)addr + len), FALSE);
+	    round_page((vm_offset_t)addr + len),
+	    VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
 }
 
 /*
diff --git a/sys/vm/vm_kern.c b/sys/vm/vm_kern.c
index ce4a450..f56075d 100644
--- a/sys/vm/vm_kern.c
+++ b/sys/vm/vm_kern.c
@@ -216,7 +216,8 @@ kmem_alloc(map, size)
 	/*
 	 * And finally, mark the data as non-pageable.
 	 */
-	(void) vm_map_wire(map, addr, addr + size, FALSE);
+	(void) vm_map_wire(map, addr, addr + size,
+	    VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
 
 	return (addr);
 }
diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c
index eddfc88..d4910cd 100644
--- a/sys/vm/vm_map.c
+++ b/sys/vm/vm_map.c
@@ -1604,19 +1604,24 @@ vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end,
  */
 int
 vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t end,
-	boolean_t user_unwire)
+    int flags)
 {
 	vm_map_entry_t entry, first_entry, tmp_entry;
 	vm_offset_t saved_start;
 	unsigned int last_timestamp;
 	int rv;
-	boolean_t need_wakeup, result;
+	boolean_t need_wakeup, result, user_unwire;
 
+	user_unwire = (flags & VM_MAP_WIRE_USER) ? TRUE : FALSE;
 	vm_map_lock(map);
 	VM_MAP_RANGE_CHECK(map, start, end);
 	if (!vm_map_lookup_entry(map, start, &first_entry)) {
-		vm_map_unlock(map);
-		return (KERN_INVALID_ADDRESS);
+		if (flags & VM_MAP_WIRE_HOLESOK)
+			first_entry = map->header.next;
+		else {
+			vm_map_unlock(map);
+			return (KERN_INVALID_ADDRESS);
+		}
 	}
 	last_timestamp = map->timestamp;
 	entry = first_entry;
@@ -1672,9 +1677,11 @@ vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t end,
 		entry->eflags |= MAP_ENTRY_IN_TRANSITION;
 		/*
 		 * Check the map for holes in the specified region.
+		 * If VM_MAP_WIRE_HOLESOK was specified, skip this check.
 		 */
-		if (entry->end < end && (entry->next == &map->header ||
-		    entry->next->start > entry->end)) {
+		if (((flags & VM_MAP_WIRE_HOLESOK) == 0) &&
+		    (entry->end < end && (entry->next == &map->header ||
+		    entry->next->start > entry->end))) {
 			end = entry->end;
 			rv = KERN_INVALID_ADDRESS;
 			goto done;
@@ -1733,19 +1740,24 @@ done:
  */
 int
 vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t end,
-	boolean_t user_wire)
+    int flags)
 {
 	vm_map_entry_t entry, first_entry, tmp_entry;
 	vm_offset_t saved_end, saved_start;
 	unsigned int last_timestamp;
 	int rv;
-	boolean_t need_wakeup, result;
+	boolean_t need_wakeup, result, user_wire;
 
+	user_wire = (flags & VM_MAP_WIRE_USER) ? TRUE : FALSE;
 	vm_map_lock(map);
 	VM_MAP_RANGE_CHECK(map, start, end);
 	if (!vm_map_lookup_entry(map, start, &first_entry)) {
-		vm_map_unlock(map);
-		return (KERN_INVALID_ADDRESS);
+		if (flags & VM_MAP_WIRE_HOLESOK)
+			first_entry = map->header.next;
+		else {
+			vm_map_unlock(map);
+			return (KERN_INVALID_ADDRESS);
+		}
 	}
 	last_timestamp = map->timestamp;
 	entry = first_entry;
@@ -1856,9 +1868,11 @@ vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t end,
 		}
 		/*
 		 * Check the map for holes in the specified region.
+		 * If VM_MAP_WIRE_HOLESOK was specified, skip this check.
 		 */
-		if (entry->end < end && (entry->next == &map->header ||
-		    entry->next->start > entry->end)) {
+		if (((flags & VM_MAP_WIRE_HOLESOK) == 0) &&
+		    (entry->end < end && (entry->next == &map->header ||
+		    entry->next->start > entry->end))) {
 			end = entry->end;
 			rv = KERN_INVALID_ADDRESS;
 			goto done;
@@ -2394,6 +2408,10 @@ vmspace_fork(struct vmspace *vm1)
 	new_map = &vm2->vm_map;	/* XXX */
 	new_map->timestamp = 1;
 
+	/* Do not inherit the MAP_WIREFUTURE property. */
+	if ((new_map->flags & MAP_WIREFUTURE) == MAP_WIREFUTURE)
+		new_map->flags &= ~MAP_WIREFUTURE;
+
 	old_entry = old_map->header.next;
 
 	while (old_entry != &old_map->header) {
@@ -2704,6 +2722,15 @@ Retry:
 	}
 
 	vm_map_unlock(map);
+	/*
+	 * Heed the MAP_WIREFUTURE flag if it was set for this process.
+	 */
+	if (rv == KERN_SUCCESS && (map->flags & MAP_WIREFUTURE))
+		vm_map_wire(map, addr, stack_entry->start,
+			    (p->p_flag & P_SYSTEM ?
+			    VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES :
+			    VM_MAP_WIRE_USER|VM_MAP_WIRE_NOHOLES));
+
 	return (rv);
 }
 
diff --git a/sys/vm/vm_map.h b/sys/vm/vm_map.h
index 62d0124..21c27e6 100644
--- a/sys/vm/vm_map.h
+++ b/sys/vm/vm_map.h
@@ -81,6 +81,7 @@
  *	vm_map_entry_t		an entry in an address map.
  */
 
+typedef u_char vm_flags_t;
 typedef u_int vm_eflags_t;
 
 /*
@@ -171,6 +172,7 @@ struct vm_map {
 	u_char needs_wakeup;
 	u_char system_map;		/* Am I a system map? */
 	u_char infork;			/* Am I in fork processing? */
+	vm_flags_t flags;		/* flags for this vm_map */
 	vm_map_entry_t root;		/* Root of a binary search tree */
 	unsigned int timestamp;		/* Version number */
 	vm_map_entry_t first_free;	/* First free space hint */
@@ -179,6 +181,11 @@ struct vm_map {
 #define	max_offset	header.end	/* (c) */
 };
 
+/*
+ * vm_flags_t values
+ */
+#define MAP_WIREFUTURE		0x01	/* wire all future pages */
+
 #ifdef	_KERNEL
 static __inline vm_offset_t
 vm_map_max(vm_map_t map)
@@ -197,6 +204,12 @@ vm_map_pmap(vm_map_t map)
 {
 	return (map->pmap);
 }
+
+static __inline void
+vm_map_modflags(vm_map_t map, vm_flags_t set, vm_flags_t clear)
+{
+	map->flags = (map->flags | set) & ~clear;
+}
 #endif	/* _KERNEL */
 
 /* 
@@ -296,6 +309,15 @@ long vmspace_resident_count(struct vmspace *vmspace);
 #define VM_FAULT_WIRE_MASK (VM_FAULT_CHANGE_WIRING|VM_FAULT_USER_WIRE)
 #define VM_FAULT_DIRTY 8		/* Dirty the page */
 
+/*
+ * vm_map_wire and vm_map_unwire option flags
+ */
+#define VM_MAP_WIRE_SYSTEM	0	/* wiring in a kernel map */
+#define VM_MAP_WIRE_USER	1	/* wiring in a user map */
+
+#define VM_MAP_WIRE_NOHOLES	0	/* region must not have holes */
+#define VM_MAP_WIRE_HOLESOK	2	/* region may have holes */
+
 #ifdef _KERNEL
 boolean_t vm_map_check_protection (vm_map_t, vm_offset_t, vm_offset_t, vm_prot_t);
 vm_map_t vm_map_create(pmap_t, vm_offset_t, vm_offset_t);
@@ -322,9 +344,9 @@ void vm_init2 (void);
 int vm_map_stack (vm_map_t, vm_offset_t, vm_size_t, vm_prot_t, vm_prot_t, int);
 int vm_map_growstack (struct proc *p, vm_offset_t addr);
 int vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t end,
-    boolean_t user_unwire);
+    int flags);
 int vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t end,
-    boolean_t user_wire);
+    int flags);
 int vmspace_swap_count (struct vmspace *vmspace);
 #endif				/* _KERNEL */
 #endif				/* _VM_MAP_ */
diff --git a/sys/vm/vm_mmap.c b/sys/vm/vm_mmap.c
index 15a6c77..b8188e4 100644
--- a/sys/vm/vm_mmap.c
+++ b/sys/vm/vm_mmap.c
@@ -1046,7 +1046,7 @@ mlock(td, uap)
 #endif
 
 	error = vm_map_wire(&td->td_proc->p_vmspace->vm_map, addr,
-		     addr + size, TRUE);
+		     addr + size, VM_MAP_WIRE_USER|VM_MAP_WIRE_NOHOLES);
 	return (error == KERN_SUCCESS ? 0 : ENOMEM);
 }
 
@@ -1064,14 +1064,54 @@ mlockall(td, uap)
 	struct thread *td;
 	struct mlockall_args *uap;
 {
-	/* mtx_lock(&Giant); */
-	/* mtx_unlock(&Giant); */
-	return 0;
+	vm_map_t map;
+	int error;
+
+	map = &td->td_proc->p_vmspace->vm_map;
+	error = 0;
+
+	if ((uap->how == 0) || ((uap->how & ~(MCL_CURRENT|MCL_FUTURE)) != 0))
+		return (EINVAL);
+
+#ifdef pmap_wired_count
+	/*
+	 * If wiring all pages in the process would cause it to exceed
+	 * a hard resource limit, return ENOMEM.
+	 */
+	if (map->size - ptoa(pmap_wired_count(vm_map_pmap(map)) >
+		td->td_proc->p_rlimit[RLIMIT_MEMLOCK].rlim_cur))
+		return (ENOMEM);
+#else
+	error = suser(td);
+	if (error)
+		return (error);
+#endif
+
+	if (uap->how & MCL_FUTURE) {
+		vm_map_lock(map);
+		vm_map_modflags(map, MAP_WIREFUTURE, 0);
+		vm_map_unlock(map);
+		error = 0;
+	}
+
+	if (uap->how & MCL_CURRENT) {
+		/*
+		 * P1003.1-2001 mandates that all currently mapped pages
+		 * will be memory resident and locked (wired) upon return
+		 * from mlockall(). vm_map_wire() will wire pages, by
+		 * calling vm_fault_wire() for each page in the region.
+		 */
+		error = vm_map_wire(map, vm_map_min(map), vm_map_max(map),
+		    VM_MAP_WIRE_USER|VM_MAP_WIRE_HOLESOK);
+		error = (error == KERN_SUCCESS ? 0 : EAGAIN);
+	}
+
+	return (error);
 }
 
 #ifndef _SYS_SYSPROTO_H_
 struct munlockall_args {
-	int	how;
+	register_t dummy;
 };
 #endif
 
@@ -1083,9 +1123,26 @@ munlockall(td, uap)
 	struct thread *td;
 	struct munlockall_args *uap;
 {
-	/* mtx_lock(&Giant); */
-	/* mtx_unlock(&Giant); */
-	return 0;
+	vm_map_t map;
+	int error;
+
+	map = &td->td_proc->p_vmspace->vm_map;
+#ifndef pmap_wired_count
+	error = suser(td);
+	if (error)
+		return (error);
+#endif
+
+	/* Clear the MAP_WIREFUTURE flag from this vm_map. */
+	vm_map_lock(map);
+	vm_map_modflags(map, 0, MAP_WIREFUTURE);
+	vm_map_unlock(map);
+
+	/* Forcibly unwire all pages. */
+	error = vm_map_unwire(map, vm_map_min(map), vm_map_max(map),
+	    VM_MAP_WIRE_USER|VM_MAP_WIRE_HOLESOK);
+
+	return (error);
 }
 
 #ifndef _SYS_SYSPROTO_H_
@@ -1125,7 +1182,7 @@ munlock(td, uap)
 #endif
 
 	error = vm_map_unwire(&td->td_proc->p_vmspace->vm_map, addr,
-		     addr + size, TRUE);
+		     addr + size, VM_MAP_WIRE_USER|VM_MAP_WIRE_NOHOLES);
 	return (error == KERN_SUCCESS ? 0 : ENOMEM);
 }
 
@@ -1282,6 +1339,15 @@ vm_mmap(vm_map_t map, vm_offset_t *addr, vm_size_t size, vm_prot_t prot,
 		if (rv != KERN_SUCCESS)
 			(void) vm_map_remove(map, *addr, *addr + size);
 	}
+
+	/*
+	 * If the process has requested that all future mappings
+	 * be wired, then heed this.
+	 */
+	if ((rv == KERN_SUCCESS) && (map->flags & MAP_WIREFUTURE))
+		vm_map_wire(map, *addr, *addr + size,
+		    VM_MAP_WIRE_USER|VM_MAP_WIRE_NOHOLES);
+
 	switch (rv) {
 	case KERN_SUCCESS:
 		return (0);
diff --git a/sys/vm/vm_unix.c b/sys/vm/vm_unix.c
index b57958e..877609f 100644
--- a/sys/vm/vm_unix.c
+++ b/sys/vm/vm_unix.c
@@ -79,7 +79,9 @@ obreak(td, uap)
 	vm_offset_t new, old, base;
 	int rv;
 	int error = 0;
+	boolean_t do_map_wirefuture;
 
+	do_map_wirefuture = FALSE;
 	new = round_page((vm_offset_t)uap->nsize);
 	vm_map_lock(&vm->vm_map);
 
@@ -121,6 +123,20 @@ obreak(td, uap)
 			goto done;
 		}
 		vm->vm_dsize += btoc(new - old);
+		/*
+		 * Handle the MAP_WIREFUTURE case for legacy applications,
+		 * by marking the newly mapped range of pages as wired.
+		 * We are not required to perform a corresponding
+		 * vm_map_unwire() before vm_map_delete() below, as
+		 * it will forcibly unwire the pages in the range.
+		 *
+		 * XXX If the pages cannot be wired, no error is returned.
+		 */
+		if ((vm->vm_map.flags & MAP_WIREFUTURE) == MAP_WIREFUTURE) {
+			if (bootverbose)
+				printf("obreak: MAP_WIREFUTURE set\n");
+			do_map_wirefuture = TRUE;
+		}
 	} else if (new < old) {
 		rv = vm_map_delete(&vm->vm_map, new, old);
 		if (rv != KERN_SUCCESS) {
@@ -131,6 +147,11 @@ obreak(td, uap)
 	}
 done:
 	vm_map_unlock(&vm->vm_map);
+
+	if (do_map_wirefuture)
+		(void) vm_map_wire(&vm->vm_map, old, new,
+		    VM_MAP_WIRE_USER|VM_MAP_WIRE_NOHOLES);
+
 	return (error);
 }