[thirdparty/glibc.git] / sysdeps / arm / dl-tlsdesc.S

/* Thread-local storage handling in the ELF dynamic linker.  ARM version.
   Copyright (C) 2006-2017 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 <arm-features.h>
#include <tls.h>
#include "tlsdesc.h"

	.text
	@ emit debug information with cfi
	@ use arm-specific pseudos for unwinding itself
	CFI_SECTIONS
	.hidden _dl_tlsdesc_return
	.global	_dl_tlsdesc_return
	.type	_dl_tlsdesc_return,#function
	cfi_startproc
	eabi_fnstart
	.align 2
_dl_tlsdesc_return:
	sfi_breg r0, \
	ldr	r0, [\B]
	BX	(lr)
	eabi_fnend
	cfi_endproc
	.size	_dl_tlsdesc_return, .-_dl_tlsdesc_return

	.hidden _dl_tlsdesc_undefweak
	.global	_dl_tlsdesc_undefweak
	.type	_dl_tlsdesc_undefweak,#function
	cfi_startproc
	eabi_fnstart
	.align 2
_dl_tlsdesc_undefweak:
	GET_TLS (r1)
	rsb 	r0, r0, #0
	BX	(lr)
	cfi_endproc
	eabi_fnend
	.size	_dl_tlsdesc_undefweak, .-_dl_tlsdesc_undefweak

#ifdef SHARED
	.hidden _dl_tlsdesc_dynamic
	.global	_dl_tlsdesc_dynamic
	.type	_dl_tlsdesc_dynamic,#function


/*
	The assembly code that follows is a rendition of the following
	C code, hand-optimized a little bit.

ptrdiff_t
_dl_tlsdesc_dynamic(struct tlsdesc *tdp)
{
       struct tlsdesc_dynamic_arg *td = tdp->argument.pointer;
       dtv_t *dtv = (dtv_t *)THREAD_DTV();
       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 - __builtin_thread_pointer();

       return __tls_get_addr (&td->tlsinfo) - __builtin_thread_pointer();
}

*/
	cfi_startproc
	eabi_fnstart
	.align 2
_dl_tlsdesc_dynamic:
	/* Our calling convention is to clobber r0, r1 and the processor
	   flags.  All others that are modified must be saved */
	eabi_save ({r2,r3,r4,lr})
	push	{r2,r3,r4,lr}
	cfi_adjust_cfa_offset (16)
	cfi_rel_offset (r2,0)
	cfi_rel_offset (r3,4)
	cfi_rel_offset (r4,8)
	cfi_rel_offset (lr,12)
	sfi_breg r0, \
	ldr	r1, [\B] /* td */
	GET_TLS (lr)
	mov	r4, r0 /* r4 = tp */
	sfi_breg r0, \
	ldr	r0, [\B]
	sfi_breg r1, \
	ldr	r2, [\B, #8] /* gen_count */
	sfi_breg r0, \
	ldr	r3, [\B]
	cmp	r2, r3
	bhi	1f
	sfi_breg r1, \
	ldr	r3, [\B]
#ifndef ARM_NO_INDEX_REGISTER
	ldr	r2, [r0, r3, lsl #3]
#else
	add	lr, r0, r3, lsl #3
	sfi_breg lr, \
	ldr	r2, [\B]
#endif
	cmn	r2, #1
	ittt	ne
	sfi_breg r1, \
	ldrne	r3, [r1, #4]
	addne	r3, r2, r3
	rsbne	r0, r4, r3
	bne	2f
1:	mov	r0, r1
	bl	__tls_get_addr
	rsb	r0, r4, r0
2:
#if ((defined (__ARM_ARCH_4T__) && defined (__THUMB_INTERWORK__)) \
     || defined (ARM_ALWAYS_BX))
	pop	{r2,r3,r4, lr}
	cfi_adjust_cfa_offset (-16)
	cfi_restore (lr)
	cfi_restore (r4)
	cfi_restore (r3)
	cfi_restore (r2)
	bx	lr
#else
	pop	{r2,r3,r4, pc}
#endif
	eabi_fnend
	cfi_endproc
	.size	_dl_tlsdesc_dynamic, .-_dl_tlsdesc_dynamic
#endif /* SHARED */

/* lazy resolved for tls descriptors.  */
	.hidden _dl_tlsdesc_lazy_resolver
	.global	_dl_tlsdesc_lazy_resolver
	.type	_dl_tlsdesc_lazy_resolver,#function
	cfi_startproc
	eabi_fnstart
	.align 2
_dl_tlsdesc_lazy_resolver:
	/* r0 points at the tlsdesc,
	   r1 points at the GOT
	   r2 was pushed by the trampoline and used as a temp,
	      we need to pop it here.
	  We push the remaining call-clobbered registers here, and also
	  R1 -- to keep the stack correctly aligned.  */
	/* Tell the unwinder that r2 has already been pushed.  */
	eabi_save ({r2})
	cfi_adjust_cfa_offset (4)
	cfi_rel_offset (r2, 0)
	eabi_save ({r0,r1,r3,ip,lr})
	push	{r0, r1, r3, ip, lr}
	cfi_adjust_cfa_offset (20)
	cfi_rel_offset (r0, 0)
	cfi_rel_offset (r1, 4)
	cfi_rel_offset (r3, 8)
	cfi_rel_offset (ip, 12)
	cfi_rel_offset (lr, 16)
	bl	_dl_tlsdesc_lazy_resolver_fixup
	pop	{r0, r1, r3, ip, lr}
	cfi_adjust_cfa_offset (-20)
	cfi_restore (lr)
	cfi_restore (ip)
	cfi_restore (r3)
	cfi_restore (r1)
	cfi_restore (r0)
	pop	{r2}
	cfi_adjust_cfa_offset (-4)
	cfi_restore (r2)
	sfi_breg r0, \
	ldr	r1, [\B, #4]
	BX	(r1)
	eabi_fnend
	cfi_endproc
	.size	_dl_tlsdesc_lazy_resolver, .-_dl_tlsdesc_lazy_resolver

/* Holder for lazy tls descriptors being resolve in another thread.

   Our calling convention is to clobber r0, r1 and the processor
   flags.  All others that are modified must be saved */
	.hidden _dl_tlsdesc_resolve_hold
	.global	_dl_tlsdesc_resolve_hold
	.type	_dl_tlsdesc_resolve_hold,#function
	cfi_startproc
	eabi_fnstart
	.align 2
_dl_tlsdesc_resolve_hold:
	/* r0 is saved so its original value can be used after the call and
	   r1 is saved only to keep the stack aligned.  (r0 points to the tls
	   descriptor, it is passed to _dl_tlsdesc_resolve_hold_fixup which
	   is a void function that may clobber r0, later r0 is used to load
	   the new resolver.)  */
	eabi_save ({r0,r1,r2,r3,ip,lr})
	push	{r0, r1, r2, r3, ip, lr}
	cfi_adjust_cfa_offset (24)
	cfi_rel_offset (r0, 0)
	cfi_rel_offset (r1, 4)
	cfi_rel_offset (r2, 8)
	cfi_rel_offset (r3, 12)
	cfi_rel_offset (ip, 16)
	cfi_rel_offset (lr, 20)
	adr	r1, _dl_tlsdesc_resolve_hold
	bl	_dl_tlsdesc_resolve_hold_fixup
	pop	{r0, r1, r2, r3, ip, lr}
	cfi_adjust_cfa_offset (-24)
	cfi_restore (lr)
	cfi_restore (ip)
	cfi_restore (r3)
	cfi_restore (r2)
	cfi_restore (r1)
	cfi_restore (r0)
	sfi_breg r0, \
	ldr     r1, [\B, #4]
	BX      (r1)
	eabi_fnend
	cfi_endproc
	.size	_dl_tlsdesc_resolve_hold, .-_dl_tlsdesc_resolve_hold
Commit	Line	Data
3447f0d7	1	/* Thread-local storage handling in the ELF dynamic linker. ARM version.
bfff8b1b	2	Copyright (C) 2006-2017 Free Software Foundation, Inc.
3447f0d7 NS	3	This file is part of the GNU C Library.
	4
	5	The GNU C Library is free software; you can redistribute it and/or
	6	modify it under the terms of the GNU Lesser General Public
	7	License as published by the Free Software Foundation; either
	8	version 2.1 of the License, or (at your option) any later version.
	9
	10	The GNU C Library is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	Lesser General Public License for more details.
	14
	15	You should have received a copy of the GNU Lesser General Public
ab84e3ff PE	16	License along with the GNU C Library. If not, see
ab84e3ff PE	17	<http://www.gnu.org/licenses/>. */
3447f0d7 NS	18
3447f0d7 NS	19	#include <sysdep.h>
6bcae146	20	#include <arm-features.h>
3447f0d7 NS	21	#include <tls.h>
	22	#include "tlsdesc.h"
	23
3447f0d7 NS	24	.text
	25	@ emit debug information with cfi
	26	@ use arm-specific pseudos for unwinding itself
f4564ff0	27	CFI_SECTIONS
3447f0d7 NS	28	.hidden _dl_tlsdesc_return
	29	.global _dl_tlsdesc_return
	30	.type _dl_tlsdesc_return,#function
	31	cfi_startproc
7214d558	32	eabi_fnstart
3447f0d7 NS	33	.align 2
3447f0d7 NS	34	_dl_tlsdesc_return:
6bcae146 RM	35	sfi_breg r0, \
6bcae146 RM	36	ldr r0, [\B]
3447f0d7	37	BX (lr)
7214d558	38	eabi_fnend
3447f0d7 NS	39	cfi_endproc
	40	.size _dl_tlsdesc_return, .-_dl_tlsdesc_return
	41
	42	.hidden _dl_tlsdesc_undefweak
	43	.global _dl_tlsdesc_undefweak
	44	.type _dl_tlsdesc_undefweak,#function
	45	cfi_startproc
7214d558	46	eabi_fnstart
3447f0d7 NS	47	.align 2
3447f0d7 NS	48	_dl_tlsdesc_undefweak:
5232b909	49	GET_TLS (r1)
3447f0d7	50	rsb r0, r0, #0
3447f0d7	51	BX (lr)
3447f0d7	52	cfi_endproc
7214d558	53	eabi_fnend
3447f0d7 NS	54	.size _dl_tlsdesc_undefweak, .-_dl_tlsdesc_undefweak
	55
	56	#ifdef SHARED
	57	.hidden _dl_tlsdesc_dynamic
	58	.global _dl_tlsdesc_dynamic
	59	.type _dl_tlsdesc_dynamic,#function
	60
	61
	62	/*
	63	The assembly code that follows is a rendition of the following
	64	C code, hand-optimized a little bit.
	65
	66	ptrdiff_t
	67	_dl_tlsdesc_dynamic(struct tlsdesc *tdp)
	68	{
	69	struct tlsdesc_dynamic_arg *td = tdp->argument.pointer;
	70	dtv_t dtv = (dtv_t )THREAD_DTV();
	71	if (__builtin_expect (td->gen_count <= dtv[0].counter
	72	&& dtv[td->tlsinfo.ti_module].pointer.val
	73	!= TLS_DTV_UNALLOCATED,
	74	1))
	75	return dtv[td->tlsinfo.ti_module].pointer.val +
	76	td->tlsinfo.ti_offset - __builtin_thread_pointer();
	77
	78	return __tls_get_addr (&td->tlsinfo) - __builtin_thread_pointer();
	79	}
	80
	81	*/
	82	cfi_startproc
7214d558	83	eabi_fnstart
3447f0d7 NS	84	.align 2
	85	_dl_tlsdesc_dynamic:
	86	/* Our calling convention is to clobber r0, r1 and the processor
	87	flags. All others that are modified must be saved */
7214d558	88	eabi_save ({r2,r3,r4,lr})
55668624	89	push {r2,r3,r4,lr}
3447f0d7 NS	90	cfi_adjust_cfa_offset (16)
	91	cfi_rel_offset (r2,0)
	92	cfi_rel_offset (r3,4)
	93	cfi_rel_offset (r4,8)
	94	cfi_rel_offset (lr,12)
6bcae146 RM	95	sfi_breg r0, \
6bcae146 RM	96	ldr r1, [\B] /* td */
5232b909	97	GET_TLS (lr)
3447f0d7	98	mov r4, r0 /* r4 = tp */
6bcae146 RM	99	sfi_breg r0, \
	100	ldr r0, [\B]
	101	sfi_breg r1, \
	102	ldr r2, [\B, #8] /* gen_count */
	103	sfi_breg r0, \
	104	ldr r3, [\B]
3447f0d7 NS	105	cmp r2, r3
3447f0d7 NS	106	bhi 1f
6bcae146 RM	107	sfi_breg r1, \
	108	ldr r3, [\B]
	109	#ifndef ARM_NO_INDEX_REGISTER
3447f0d7	110	ldr r2, [r0, r3, lsl #3]
6bcae146 RM	111	#else
	112	add lr, r0, r3, lsl #3
	113	sfi_breg lr, \
	114	ldr r2, [\B]
	115	#endif
3447f0d7	116	cmn r2, #1
6ccd0107	117	ittt ne
12290c06	118	sfi_breg r1, \
3447f0d7 NS	119	ldrne r3, [r1, #4]
	120	addne r3, r2, r3
	121	rsbne r0, r4, r3
	122	bne 2f
	123	1: mov r0, r1
	124	bl __tls_get_addr
	125	rsb r0, r4, r0
d137b6dc	126	2:
6bcae146 RM	127	#if ((defined (__ARM_ARCH_4T__) && defined (__THUMB_INTERWORK__)) \
6bcae146 RM	128	\|\| defined (ARM_ALWAYS_BX))
d137b6dc	129	pop {r2,r3,r4, lr}
3447f0d7 NS	130	cfi_adjust_cfa_offset (-16)
	131	cfi_restore (lr)
	132	cfi_restore (r4)
	133	cfi_restore (r3)
	134	cfi_restore (r2)
d137b6dc RH	135	bx lr
	136	#else
	137	pop {r2,r3,r4, pc}
	138	#endif
7214d558	139	eabi_fnend
3447f0d7 NS	140	cfi_endproc
	141	.size _dl_tlsdesc_dynamic, .-_dl_tlsdesc_dynamic
	142	#endif /* SHARED */
	143
	144	/* lazy resolved for tls descriptors. */
	145	.hidden _dl_tlsdesc_lazy_resolver
	146	.global _dl_tlsdesc_lazy_resolver
	147	.type _dl_tlsdesc_lazy_resolver,#function
	148	cfi_startproc
7214d558	149	eabi_fnstart
3447f0d7 NS	150	.align 2
	151	_dl_tlsdesc_lazy_resolver:
	152	/* r0 points at the tlsdesc,
	153	r1 points at the GOT
	154	r2 was pushed by the trampoline and used as a temp,
	155	we need to pop it here.
	156	We push the remaining call-clobbered registers here, and also
	157	R1 -- to keep the stack correctly aligned. */
	158	/* Tell the unwinder that r2 has already been pushed. */
7214d558	159	eabi_save ({r2})
3447f0d7 NS	160	cfi_adjust_cfa_offset (4)
3447f0d7 NS	161	cfi_rel_offset (r2, 0)
7214d558	162	eabi_save ({r0,r1,r3,ip,lr})
55668624	163	push {r0, r1, r3, ip, lr}
3447f0d7 NS	164	cfi_adjust_cfa_offset (20)
	165	cfi_rel_offset (r0, 0)
	166	cfi_rel_offset (r1, 4)
	167	cfi_rel_offset (r3, 8)
	168	cfi_rel_offset (ip, 12)
	169	cfi_rel_offset (lr, 16)
	170	bl _dl_tlsdesc_lazy_resolver_fixup
55668624	171	pop {r0, r1, r3, ip, lr}
3447f0d7 NS	172	cfi_adjust_cfa_offset (-20)
	173	cfi_restore (lr)
	174	cfi_restore (ip)
	175	cfi_restore (r3)
	176	cfi_restore (r1)
	177	cfi_restore (r0)
55668624	178	pop {r2}
3447f0d7 NS	179	cfi_adjust_cfa_offset (-4)
3447f0d7 NS	180	cfi_restore (r2)
6bcae146 RM	181	sfi_breg r0, \
6bcae146 RM	182	ldr r1, [\B, #4]
3447f0d7	183	BX (r1)
7214d558	184	eabi_fnend
3447f0d7 NS	185	cfi_endproc
	186	.size _dl_tlsdesc_lazy_resolver, .-_dl_tlsdesc_lazy_resolver
	187
	188	/* Holder for lazy tls descriptors being resolve in another thread.
36ffe739 WN	189
	190	Our calling convention is to clobber r0, r1 and the processor
	191	flags. All others that are modified must be saved */
3447f0d7 NS	192	.hidden _dl_tlsdesc_resolve_hold
	193	.global _dl_tlsdesc_resolve_hold
	194	.type _dl_tlsdesc_resolve_hold,#function
	195	cfi_startproc
7214d558	196	eabi_fnstart
3447f0d7 NS	197	.align 2
3447f0d7 NS	198	_dl_tlsdesc_resolve_hold:
1fae5a68 SN	199	/* r0 is saved so its original value can be used after the call and
	200	r1 is saved only to keep the stack aligned. (r0 points to the tls
	201	descriptor, it is passed to _dl_tlsdesc_resolve_hold_fixup which
	202	is a void function that may clobber r0, later r0 is used to load
	203	the new resolver.) */
	204	eabi_save ({r0,r1,r2,r3,ip,lr})
	205	push {r0, r1, r2, r3, ip, lr}
	206	cfi_adjust_cfa_offset (24)
	207	cfi_rel_offset (r0, 0)
	208	cfi_rel_offset (r1, 4)
	209	cfi_rel_offset (r2, 8)
	210	cfi_rel_offset (r3, 12)
	211	cfi_rel_offset (ip, 16)
	212	cfi_rel_offset (lr, 20)
36ffe739	213	adr r1, _dl_tlsdesc_resolve_hold
3447f0d7	214	bl _dl_tlsdesc_resolve_hold_fixup
1fae5a68 SN	215	pop {r0, r1, r2, r3, ip, lr}
1fae5a68 SN	216	cfi_adjust_cfa_offset (-24)
3447f0d7 NS	217	cfi_restore (lr)
	218	cfi_restore (ip)
	219	cfi_restore (r3)
3447f0d7	220	cfi_restore (r2)
1fae5a68 SN	221	cfi_restore (r1)
1fae5a68 SN	222	cfi_restore (r0)
6bcae146 RM	223	sfi_breg r0, \
6bcae146 RM	224	ldr r1, [\B, #4]
3447f0d7	225	BX (r1)
7214d558	226	eabi_fnend
3447f0d7 NS	227	cfi_endproc
3447f0d7 NS	228	.size _dl_tlsdesc_resolve_hold, .-_dl_tlsdesc_resolve_hold