VM_MAP_STACK(9) BSD Kernel Developer's Manual VM_MAP_STACK(9)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).
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)
call.
IMPLEMENTATION NOTES
The vm_map_stack() function calls vm_map_insert(9) to create its map‐
pings.
The vm_map_growstack() function acquires the Giant lock, and 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 allo‐
cated 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 map‐
ping, KERN_NO_SPACE is returned.
Other possible return values for this function are documented in
vm_map_insert(9).
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() func‐
tion previously located in the file vm_machdep.c.
SEE ALSOvm_map(9), vm_map_insert(9)AUTHORS
This manual page was written by Bruce M Simpson ⟨bms@spc.org⟩.
BSD July 19, 2003 BSD
