SET_THREAD_AREA(2)                  Linux Programmer's Manual                  SET_THREAD_AREA(2)



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);

       Note: There is no glibc wrapper for this system call; see NOTES.

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 system call, since it is generally intended only
       for use by threading libraries.  In the unlikely event that you want to call it  directly,
       use syscall(2).

SEE ALSO
       get_thread_area(2)

COLOPHON
       This  page  is  part of release 3.74 of the Linux man-pages project.  A description of the
       project, information about reporting bugs, and the latest version of  this  page,  can  be
       found at http://www.kernel.org/doc/man-pages/.



Linux                                       2012-07-13                         SET_THREAD_AREA(2)