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+.\"
+.\" Copyright (c) 2003 Bruce M Simpson <bms@spc.org>
+.\" All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\" $FreeBSD$
+.\"
+.Dd January 11, 2013
+.Dt VM_MAP_STACK 9
+.Os
+.Sh NAME
+.Nm vm_map_stack ,
+.Nm vm_map_growstack
+.Nd manage process stacks
+.Sh SYNOPSIS
+.In sys/param.h
+.In vm/vm.h
+.In vm/vm_map.h
+.Ft int
+.Fo vm_map_stack
+.Fa "vm_map_t map" "vm_offset_t addrbos" "vm_size_t max_ssize" "vm_prot_t prot"
+.Fa "vm_prot_t max" "int cow"
+.Fc
+.Ft int
+.Fn vm_map_growstack "struct proc *p" "vm_offset_t addr"
+.Sh DESCRIPTION
+The
+.Fn vm_map_stack
+function maps a process stack for a new process image.
+The stack is mapped
+.Fa addrbos
+in
+.Fa map ,
+with a maximum size of
+.Fa max_ssize .
+Copy-on-write flags passed in
+.Fa cow
+are also applied to the new mapping.
+Protection bits are supplied by
+.Fa prot
+and
+.Fa max .
+.Pp
+It is typically called by
+.Xr execve 2 .
+.Pp
+The
+.Fn vm_map_growstack
+function is responsible for growing a stack for the process
+.Fa p
+to the desired address
+.Fa addr ,
+similar to the legacy
+.Xr sbrk 2
+call.
+.Sh IMPLEMENTATION NOTES
+The
+.Fn vm_map_stack
+function calls
+.Xr vm_map_insert 9
+to create its mappings.
+.Pp
+The
+.Fn vm_map_stack
+and
+.Fn vm_map_growstack
+functions acquire the process lock on
+.Fa p
+for the duration of the call.
+.Sh RETURN VALUES
+The
+.Fn vm_map_stack
+function returns
+.Dv KERN_SUCCESS
+if the mapping was allocated successfully.
+.Pp
+Otherwise,
+if mapping the stack would exceed the process's VMEM resource limit,
+or if the specified bottom-of-stack address is out of range for the map,
+or if there is already a mapping at the address which would result,
+or if
+.Fa max_ssize
+could not be accommodated within the current mapping,
+.Dv KERN_NO_SPACE
+is returned.
+.Pp
+Other possible return values for this function are documented in
+.Xr vm_map_insert 9 .
+.Pp
+The
+.Fn vm_map_growstack
+function returns
+.Dv KERN_SUCCESS
+if
+.Fa addr
+is already mapped, or if the stack was grown successfully.
+.Pp
+It also returns
+.Dv KERN_SUCCESS
+if
+.Fa addr
+is outside the stack range; this is done in order to preserve
+compatibility with the deprecated
+.Fn grow
+function previously located in the file
+.Pa vm_machdep.c .
+.Sh SEE ALSO
+.Xr vm_map 9 ,
+.Xr vm_map_insert 9
+.Sh AUTHORS
+This manual page was written by
+.An Bruce M Simpson Aq Mt bms@spc.org .