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/* Thread-local storage handling in the ELF dynamic linker. i386 version.
Copyright (C) 2004-2024 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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
<https://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include <tls.h>
#include <cpu-features-offsets.h>
#include <features-offsets.h>
#include "tlsdesc.h"
#ifndef DL_STACK_ALIGNMENT
/* Due to GCC bug:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58066
__tls_get_addr may be called with 4-byte stack alignment. Although
this bug has been fixed in GCC 4.9.4, 5.3 and 6, we can't assume
that stack will be always aligned at 16 bytes. */
# define DL_STACK_ALIGNMENT 4
#endif
/* True if _dl_tlsdesc_dynamic should align stack for STATE_SAVE or align
stack to MINIMUM_ALIGNMENT bytes before calling ___tls_get_addr. */
#define DL_RUNTIME_RESOLVE_REALIGN_STACK \
(STATE_SAVE_ALIGNMENT > DL_STACK_ALIGNMENT \
|| MINIMUM_ALIGNMENT > DL_STACK_ALIGNMENT)
.text
/* This function is used to compute the TP offset for symbols in
Static TLS, i.e., whose TP offset is the same for all
threads.
The incoming %eax points to the TLS descriptor, such that
0(%eax) points to _dl_tlsdesc_return itself, and 4(%eax) holds
the TP offset of the symbol corresponding to the object
denoted by the argument. */
.hidden _dl_tlsdesc_return
.global _dl_tlsdesc_return
.type _dl_tlsdesc_return,@function
cfi_startproc
.align 16
_dl_tlsdesc_return:
movl 4(%eax), %eax
ret
cfi_endproc
.size _dl_tlsdesc_return, .-_dl_tlsdesc_return
/* This function is used for undefined weak TLS symbols, for
which the base address (i.e., disregarding any addend) should
resolve to NULL.
%eax points to the TLS descriptor, such that 0(%eax) points to
_dl_tlsdesc_undefweak itself, and 4(%eax) holds the addend.
We return the addend minus the TP, such that, when the caller
adds TP, it gets the addend back. If that's zero, as usual,
that's most likely a NULL pointer. */
.hidden _dl_tlsdesc_undefweak
.global _dl_tlsdesc_undefweak
.type _dl_tlsdesc_undefweak,@function
cfi_startproc
.align 16
_dl_tlsdesc_undefweak:
movl 4(%eax), %eax
subl %gs:0, %eax
ret
cfi_endproc
.size _dl_tlsdesc_undefweak, .-_dl_tlsdesc_undefweak
#ifdef SHARED
# define USE_FNSAVE
# define MINIMUM_ALIGNMENT 4
# define STATE_SAVE_ALIGNMENT 4
# define _dl_tlsdesc_dynamic _dl_tlsdesc_dynamic_fnsave
# include "dl-tlsdesc-dynamic.h"
# undef _dl_tlsdesc_dynamic
# undef MINIMUM_ALIGNMENT
# undef USE_FNSAVE
# define MINIMUM_ALIGNMENT 16
# define USE_FXSAVE
# define STATE_SAVE_ALIGNMENT 16
# define _dl_tlsdesc_dynamic _dl_tlsdesc_dynamic_fxsave
# include "dl-tlsdesc-dynamic.h"
# undef _dl_tlsdesc_dynamic
# undef USE_FXSAVE
# define USE_XSAVE
# define STATE_SAVE_ALIGNMENT 64
# define _dl_tlsdesc_dynamic _dl_tlsdesc_dynamic_xsave
# include "dl-tlsdesc-dynamic.h"
# undef _dl_tlsdesc_dynamic
# undef USE_XSAVE
# define USE_XSAVEC
# define STATE_SAVE_ALIGNMENT 64
# define _dl_tlsdesc_dynamic _dl_tlsdesc_dynamic_xsavec
# include "dl-tlsdesc-dynamic.h"
# undef _dl_tlsdesc_dynamic
# undef USE_XSAVEC
#endif /* SHARED */
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