SET_THREAD_AREA

Section: Linux Programmer's Manual (2)
Updated: 2008-11-27
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NAME

set_thread_area - Set a Thread Local Storage (TLS) area

SYNOPSIS

#include <linux/unistd.h>
#include <asm/ldt.h>

int set_thread_area(struct user_desc *u_info);

DESCRIPTION

set_thread_area() sets an entry in the current thread's Thread Local Storage (TLS) array. The TLS array entry set by set_thread_area() corresponds to the value of u_info->entry_number passed in by the user. If this value is in bounds, set_thread_area() copies the TLS descriptor pointed to by u_info into the thread's TLS array.

When set_thread_area() is passed an entry_number of -1, it uses a free TLS entry. If set_thread_area() finds a free TLS entry, the value of u_info->entry_number is set upon return to show which entry was changed.

RETURN VALUE

set_thread_area() returns 0 on success, and -1 on failure, with errno set appropriately.

ERRORS

EINVAL: u_info->entry_number is out of bounds.
EFAULT: u_info is an invalid pointer.
ESRCH: A free TLS entry could not be located.

VERSIONS

A version of set_thread_area() first appeared in Linux 2.5.29.

CONFORMING TO

set_thread_area() is Linux-specific and should not be used in programs that are intended to be portable.

NOTES

Glibc does not provide a wrapper for this function; call it using syscall(2).

COLOPHON

This page is part of release 3.22 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.