/* Thread-local storage handling in the ELF dynamic linker.  i386 version.

   Copyright (C) 2004-2018 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

   <http://www.gnu.org/licenses/>.  */

#include <sysdep.h>

#include <tls.h>

#include "tlsdesc.h"

	.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:

	_CET_ENDBR

	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:

	_CET_ENDBR

	movl	4(%eax), %eax

	subl	%gs:0, %eax

	ret

	cfi_endproc

	.size	_dl_tlsdesc_undefweak, .-_dl_tlsdesc_undefweak

#ifdef SHARED

	.hidden _dl_tlsdesc_dynamic

	.global	_dl_tlsdesc_dynamic

	.type	_dl_tlsdesc_dynamic,@function

     /* This function is used for symbols that need dynamic TLS.

	%eax points to the TLS descriptor, such that 0(%eax) points to

	_dl_tlsdesc_dynamic itself, and 4(%eax) points to a struct

	tlsdesc_dynamic_arg object.  It must return in %eax the offset

	between the thread pointer and the object denoted by the

	argument, without clobbering any registers.

	The assembly code that follows is a rendition of the following

	C code, hand-optimized a little bit.

ptrdiff_t

__attribute__ ((__regparm__ (1)))

_dl_tlsdesc_dynamic (struct tlsdesc *tdp)

{

  struct tlsdesc_dynamic_arg *td = tdp->arg;

  dtv_t *dtv = *(dtv_t **)((char *)__thread_pointer + DTV_OFFSET);

  if (__builtin_expect (td->gen_count <= dtv[0].counter

			&& (dtv[td->tlsinfo.ti_module].pointer.val

			    != TLS_DTV_UNALLOCATED),

			1))

    return dtv[td->tlsinfo.ti_module].pointer.val + td->tlsinfo.ti_offset

      - __thread_pointer;

  return ___tls_get_addr (&td->tlsinfo) - __thread_pointer;

}

*/

	cfi_startproc

	.align 16

_dl_tlsdesc_dynamic:

	_CET_ENDBR

	/* Like all TLS resolvers, preserve call-clobbered registers.

	   We need two scratch regs anyway.  */

	subl	$28, %esp

	cfi_adjust_cfa_offset (28)

	movl	%ecx, 20(%esp)

	movl	%edx, 24(%esp)

	movl	TLSDESC_ARG(%eax), %eax

	movl	%gs:DTV_OFFSET, %edx

	movl	TLSDESC_GEN_COUNT(%eax), %ecx

	cmpl	(%edx), %ecx

	ja	.Lslow

	movl	TLSDESC_MODID(%eax), %ecx

	movl	(%edx,%ecx,8), %edx

	cmpl	$-1, %edx

	je	.Lslow

	movl	TLSDESC_MODOFF(%eax), %eax

	addl	%edx, %eax

.Lret:

	movl	20(%esp), %ecx

	subl	%gs:0, %eax

	movl	24(%esp), %edx

	addl	$28, %esp

	cfi_adjust_cfa_offset (-28)

	ret

	.p2align 4,,7

.Lslow:

	cfi_adjust_cfa_offset (28)

#ifdef NO_RTLD_HIDDEN

	call	JUMPTARGET (___tls_get_addr)

#else

	call	HIDDEN_JUMPTARGET (___tls_get_addr)

#endif

	jmp	.Lret

	cfi_endproc

	.size	_dl_tlsdesc_dynamic, .-_dl_tlsdesc_dynamic

#endif /* SHARED */

     /* This function is a wrapper for a lazy resolver for TLS_DESC

	REL relocations that reference the *ABS* segment in their own

	link maps.  %ebx points to the caller's GOT.  %eax points to a

	TLS descriptor, such that 0(%eax) holds the address of the

	resolver wrapper itself (unless some other thread beat us to

	it) and 4(%eax) holds the addend in the relocation.

	When the actual resolver returns, it will have adjusted the

	TLS descriptor such that we can tail-call it for it to return

	the TP offset of the symbol.  */

	.hidden _dl_tlsdesc_resolve_abs_plus_addend

	.global	_dl_tlsdesc_resolve_abs_plus_addend

	.type	_dl_tlsdesc_resolve_abs_plus_addend,@function

	cfi_startproc

	.align 16

_dl_tlsdesc_resolve_abs_plus_addend:

0:

	_CET_ENDBR

	pushl	%eax

	cfi_adjust_cfa_offset (4)

	pushl	%ecx

	cfi_adjust_cfa_offset (4)

	pushl	%edx

	cfi_adjust_cfa_offset (4)

	movl	$1f - 0b, %ecx

	movl	4(%ebx), %edx

	call	_dl_tlsdesc_resolve_abs_plus_addend_fixup

1:

	popl	%edx

	cfi_adjust_cfa_offset (-4)

	popl	%ecx

	cfi_adjust_cfa_offset (-4)

	popl	%eax

	cfi_adjust_cfa_offset (-4)

	jmp	*(%eax)

	cfi_endproc

	.size	_dl_tlsdesc_resolve_abs_plus_addend, .-_dl_tlsdesc_resolve_abs_plus_addend

     /* This function is a wrapper for a lazy resolver for TLS_DESC

	REL relocations that had zero addends.  %ebx points to the

	caller's GOT.  %eax points to a TLS descriptor, such that

	0(%eax) holds the address of the resolver wrapper itself

	(unless some other thread beat us to it) and 4(%eax) holds a

	pointer to the relocation.

	When the actual resolver returns, it will have adjusted the

	TLS descriptor such that we can tail-call it for it to return

	the TP offset of the symbol.  */

	.hidden _dl_tlsdesc_resolve_rel

	.global	_dl_tlsdesc_resolve_rel

	.type	_dl_tlsdesc_resolve_rel,@function

	cfi_startproc

	.align 16

_dl_tlsdesc_resolve_rel:

0:

	_CET_ENDBR

	pushl	%eax

	cfi_adjust_cfa_offset (4)

	pushl	%ecx

	cfi_adjust_cfa_offset (4)

	pushl	%edx

	cfi_adjust_cfa_offset (4)

	movl	$1f - 0b, %ecx

	movl	4(%ebx), %edx

	call	_dl_tlsdesc_resolve_rel_fixup

1:

	popl	%edx

	cfi_adjust_cfa_offset (-4)

	popl	%ecx

	cfi_adjust_cfa_offset (-4)

	popl	%eax

	cfi_adjust_cfa_offset (-4)

	jmp	*(%eax)

	cfi_endproc

	.size	_dl_tlsdesc_resolve_rel, .-_dl_tlsdesc_resolve_rel

     /* This function is a wrapper for a lazy resolver for TLS_DESC

	RELA relocations.  %ebx points to the caller's GOT.  %eax

	points to a TLS descriptor, such that 0(%eax) holds the

	address of the resolver wrapper itself (unless some other

	thread beat us to it) and 4(%eax) holds a pointer to the

	relocation.

	When the actual resolver returns, it will have adjusted the

	TLS descriptor such that we can tail-call it for it to return

	the TP offset of the symbol.  */

	.hidden _dl_tlsdesc_resolve_rela

	.global	_dl_tlsdesc_resolve_rela

	.type	_dl_tlsdesc_resolve_rela,@function

	cfi_startproc

	.align 16

_dl_tlsdesc_resolve_rela:

0:

	_CET_ENDBR

	pushl	%eax

	cfi_adjust_cfa_offset (4)

	pushl	%ecx

	cfi_adjust_cfa_offset (4)

	pushl	%edx

	cfi_adjust_cfa_offset (4)

	movl	$1f - 0b, %ecx

	movl	4(%ebx), %edx

	call	_dl_tlsdesc_resolve_rela_fixup

1:

	popl	%edx

	cfi_adjust_cfa_offset (-4)

	popl	%ecx

	cfi_adjust_cfa_offset (-4)

	popl	%eax

	cfi_adjust_cfa_offset (-4)

	jmp	*(%eax)

	cfi_endproc

	.size	_dl_tlsdesc_resolve_rela, .-_dl_tlsdesc_resolve_rela

     /* This function is a placeholder for lazy resolving of TLS

	relocations.  Once some thread starts resolving a TLS

	relocation, it sets up the TLS descriptor to use this

	resolver, such that other threads that would attempt to

	resolve it concurrently may skip the call to the original lazy

	resolver and go straight to a condition wait.

	When the actual resolver returns, it will have adjusted the

	TLS descriptor such that we can tail-call it for it to return

	the TP offset of the symbol.  */

	.hidden _dl_tlsdesc_resolve_hold

	.global	_dl_tlsdesc_resolve_hold

	.type	_dl_tlsdesc_resolve_hold,@function

	cfi_startproc

	.align 16

_dl_tlsdesc_resolve_hold:

0:

	_CET_ENDBR

	pushl	%eax

	cfi_adjust_cfa_offset (4)

	pushl	%ecx

	cfi_adjust_cfa_offset (4)

	pushl	%edx

	cfi_adjust_cfa_offset (4)

	movl	$1f - 0b, %ecx

	movl	4(%ebx), %edx

	call	_dl_tlsdesc_resolve_hold_fixup

1:

	popl	%edx

	cfi_adjust_cfa_offset (-4)

	popl	%ecx

	cfi_adjust_cfa_offset (-4)

	popl	%eax

	cfi_adjust_cfa_offset (-4)

	jmp	*(%eax)

	cfi_endproc

	.size	_dl_tlsdesc_resolve_hold, .-_dl_tlsdesc_resolve_hold