.\" Copyright, the authors of the Linux man-pages project
.\"
.\" SPDX-License-Identifier: Linux-man-pages-copyleft
.\"
.TH PR_SET_MM_START_DATA 2const 2025-05-17 "Linux man-pages 6.16"
.SH NAME
PR_SET_MM_START_DATA,
PR_SET_MM_END_DATA
\-
modify kernel memory map descriptor fields
.SH LIBRARY
Standard C library
.RI ( libc ,\~ \-lc )
.SH SYNOPSIS
.nf
.BR "#include <linux/prctl.h>" "  /* Definition of " PR_* " constants */"
.B #include <sys/prctl.h>
.P
.BI "int prctl(PR_SET_MM, PR_SET_MM_START_DATA, unsigned long " addr ", 0L, 0L);"
.BI "int prctl(PR_SET_MM, PR_SET_MM_END_DATA, unsigned long " addr ", 0L, 0L);"
.fi
.SH DESCRIPTION
.TP
.B 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.
.TP
.B 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.
.SH RETURN VALUE
On success,
0 is returned.
On error, \-1 is returned, and
.I errno
is set to indicate the error.
.SH ERRORS
.TP
.B EINVAL
.I addr
is greater than
.B TASK_SIZE
(the limit on the size of the user address space for this architecture).
.TP
.B EINVAL
The permissions of the corresponding memory area are not as required.
.SH STANDARDS
Linux.
.SH HISTORY
Linux 3.3.
.\" commit 028ee4be34a09a6d48bdf30ab991ae933a7bc036
.SH SEE ALSO
.BR prctl (2)