man2/set_thread_area.2

   1 .\" Copyright (C) 2003 Free Software Foundation, Inc.
   2 .\" This file is distributed according to the GNU General Public License.
   3 .\" See the file COPYING in the top level source directory for details.
   4 .\"
   5 .\" Author: Kent Yoder
   6 .\"
   7 .TH SET_THREAD_AREA 2 2003-02-21 "Linux 2.5.29" "Linux Programmer's Manual"
   8 .SH NAME
   9 set_thread_area \- Set a Thread Local Storage (TLS) area
  10 .SH "SYNOPSIS"
  11 .B #include <linux/unistd.h>
  12 .br
  13 .B #include <asm/ldt.h>
  14 .sp
  15 .BI "int set_thread_area(struct user_desc *" u_info );
  16 .SH "DESCRIPTION"
  17 .BR set_thread_area ()
  18 sets an entry in the current thread's Thread Local Storage (TLS) array.
  19 The TLS array entry set by
  20 .BR set_thread_area ()
  21 corresponds to the value of
  22 .I u_info->entry_number
  23 passed in by the user.
  24 If this value is in bounds,
  25 .BR set_thread_area ()
  26 copies the TLS descriptor pointed to by
  27 .I u_info
  28 into the thread's TLS array.
  29 .PP
  30 When
  31 .BR set_thread_area ()
  32 is passed an
  33 .I entry_number
  34 of \-1, it uses a free TLS entry.
  35 If
  36 .BR set_thread_area ()
  37 finds a free TLS entry, the value of
  38 .I u_info->entry_number
  39 is set upon return to show which entry was changed.
  40 .SH "RETURN VALUE"
  41 .BR set_thread_area ()
  42 returns 0 on success, and \-1 on failure, with
  43 .I errno
  44 set appropriately.
  45 .SH "ERRORS"
  46 .TP
  47 .B EINVAL
  48 \fIu_info->\fR\fIentry_number\fR is out of bounds.
  49 .TP
  50 .B EFAULT
  51 \fIu_info\fR is an invalid pointer.
  52 .TP
  53 .B ESRCH
  54 A free TLS entry could not be located.
  55 .SH "VERSIONS"
  56 A version of
  57 .BR set_thread_area ()
  58 first appeared in Linux 2.5.29.
  59 .SH "CONFORMING TO"
  60 .BR set_thread_area ()
  61 is Linux specific and should not be used in programs that are intended
  62 to be portable.
  63 .SH "SEE ALSO"
  64 .BR get_thread_area (2).