---
name: "vm_map_stack"
section: "9"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["linux", "freebsd"]
url: "https://new.carta.tech/vm_map_growstack"
---

# vm\_map\_stack(9)

manage process stacks

Part of [vm\_map\_growstack(9)](/vm_map_growstack/9.md).

## NAME

**vm\_map\_stack**, **vm\_map\_growstack** – manage process stacks

## SYNOPSIS

**#include \<sys/param.h\>**

**#include \<vm/vm.h\>**

**#include \<vm/vm\_map.h\>**

*int*\

**vm\_map\_stack**(*vm\_map\_t map*, *vm\_offset\_t addrbos*, *vm\_size\_t max\_ssize*, *vm\_prot\_t prot*, *vm\_prot\_t max*, *int cow*);

*int*\

**vm\_map\_growstack**(*struct proc \*p*, *vm\_offset\_t addr*);

## DESCRIPTION

The **vm\_map\_stack**() function maps a process stack for a new process image. The stack is mapped *addrbos* in *map*, with a maximum size of *max\_ssize*. Copy-on-write flags passed in *cow* are also applied to the new mapping. Protection bits are supplied by *prot* and *max*.

It is typically called by [execve(2)](/execve/2.md).

The **vm\_map\_growstack**() function is responsible for growing a stack for the process *p* to the desired address *addr*, similar to the legacy [sbrk(2)](/sbrk/2.md) call.

## IMPLEMENTATION NOTES

The **vm\_map\_stack**() function calls [vm\_map\_insert(9)](/vm_map_insert/9.md) to create its mappings.

The **vm\_map\_stack**() and **vm\_map\_growstack**() functions acquire the process lock on *p* for the duration of the call.

## RETURN VALUES

The **vm\_map\_stack**() function returns KERN\_SUCCESS if the mapping was allocated successfully.

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 *max\_ssize* could not be accommodated within the current mapping, KERN\_NO\_SPACE is returned.

Other possible return values for this function are documented in [vm\_map\_insert(9)](/vm_map_insert/9.md).

The **vm\_map\_growstack**() function returns KERN\_SUCCESS if *addr* is already mapped, or if the stack was grown successfully.

It also returns KERN\_SUCCESS if *addr* is outside the stack range; this is done in order to preserve compatibility with the deprecated **grow**() function previously located in the file *vm\_machdep.c*.

## SEE ALSO

[vm\_map(9)](/vm_map/9.md), [vm\_map\_insert(9)](/vm_map_insert/9.md)

## AUTHORS

This manual page was written by Bruce M Simpson ⟨*bms@spc.org*⟩.