PR_SET_MM_START_DATA(2const)                      PR_SET_MM_START_DATA(2const)

NAME
       PR_SET_MM_START_DATA, PR_SET_MM_END_DATA - modify kernel memory map
       descriptor fields

LIBRARY
       Standard C library (libc, -lc)

SYNOPSIS
       #include <linux/prctl.h>  /* Definition of PR_* constants */
       #include <sys/prctl.h>

       int prctl(PR_SET_MM, PR_SET_MM_START_DATA, unsigned long addr, 0L, 0L);
       int prctl(PR_SET_MM, PR_SET_MM_END_DATA, unsigned long addr, 0L, 0L);

DESCRIPTION
       PR_SET_MM_START_DATA
              Set the address above which initialized and uninitialized (bss)
              data are placed.  The corresponding memory area must be readable
              and writable, but not executable or shareable.

       PR_SET_MM_END_DATA
              Set the address below which initialized and uninitialized (bss)
              data are placed.  The corresponding memory area must be readable
              and writable, but not executable or shareable.

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 The permissions of the corresponding memory area are not as
              required.

STANDARDS
       Linux.

HISTORY
       Linux 3.3.

SEE ALSO
       prctl(2)

Linux man-pages 6.19              2026-02-08      PR_SET_MM_START_DATA(2const)