glibc/sysdeps/unix/sysv/linux/i386/createthread.c

49 lines
2.1 KiB
C

/* Copyright (C) 2002-2014 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
/* The "thread register" gets initialized from a segment descriptor.
Initialize such a descriptor first. */
#define PREPARE_CREATE \
union user_desc_init desc; \
\
/* Describe the thread-local storage segment. */ \
\
/* The 'entry_number' field. The first three bits of the segment \
register value select the GDT, ignore them. We get the index \
from the value of the %gs register in the current thread. */ \
desc.vals[0] = TLS_GET_GS () >> 3; \
/* The 'base_addr' field. Pointer to the TCB. */ \
desc.vals[1] = (unsigned long int) pd; \
/* The 'limit' field. We use 4GB which is 0xfffff pages. */ \
desc.vals[2] = 0xfffff; \
/* Collapsed value of the bitfield: \
.seg_32bit = 1 \
.contents = 0 \
.read_exec_only = 0 \
.limit_in_pages = 1 \
.seg_not_present = 0 \
.useable = 1 */ \
desc.vals[3] = 0x51
/* Value passed to 'clone' for initialization of the thread register. */
#define TLS_VALUE &desc.desc
/* Get the real implementation. */
#include <nptl/sysdeps/pthread/createthread.c>