pr_set_mm_start_brk(2const) - BetterMan

pr_set_mm_start_brk(2const)

modify kernel memory map descriptor fields

distropkg manpages-dev@6.9.1-1dataset 2026-04-01T06:19:02Z+debian+ec4110e+mandoc:1.14.6-4

Synopsis

#include <linux/prctl.h>
  /* Definition of 
PR_*
 constants */
#include <sys/prctl.h>
int prctl(PR_SET_MM, PR_SET_MM_START_BRK, unsigned long 
addr
, 0L, 0L);

—

Options · 2

EINVAL	addr is greater than TASK_SIZE (the limit on the size of the user address space for this architecture).
EINVAL	addr is less than or equal to the end of the data segment or specifies a value that would cause the RLIMIT_DATA resource limit to be exceeded.

NAME

PR_SET_MM_START_BRK - modify kernel memory map descriptor fields

SYNOPSIS

bash

#include <linux/prctl.h>\n  /* Definition of \nPR_*\n constants */
\n#include <sys/prctl.h>

bash

int prctl(PR_SET_MM, PR_SET_MM_START_BRK, unsigned long \naddr\n, 0L, 0L);

DESCRIPTION

Set the address above which the program heap can be expanded with brk(2) call.

The address must be greater than the ending address of the current program data segment. In addition, the combined size of the resulting heap and the data segment can't exceed the RLIMIT_DATA resource limit (see setrlimit(2)).

RETURN VALUE

On success, 0 is returned. On error, -1 is returned, and errno is set to indicate the error.

ERRORS

EINVAL: addr is greater than TASK_SIZE (the limit on the size of the user address space for this architecture).
EINVAL: addr is less than or equal to the end of the data segment or specifies a value that would cause the RLIMIT_DATA resource limit to be exceeded.

STANDARDS

Linux.

HISTORY

Linux 3.3.