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-rw-r--r--sysdeps/arm/dl-tlsdesc.S226
1 files changed, 226 insertions, 0 deletions
diff --git a/sysdeps/arm/dl-tlsdesc.S b/sysdeps/arm/dl-tlsdesc.S
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+++ b/sysdeps/arm/dl-tlsdesc.S
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+/* Thread-local storage handling in the ELF dynamic linker.  ARM version.
+   Copyright (C) 2006-2014 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.
+   Same ABI as the lazy resolver itself.  */
+	.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:
+	/* 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)
+	adr	r2, _dl_tlsdesc_resolve_hold
+	bl	_dl_tlsdesc_resolve_hold_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_resolve_hold, .-_dl_tlsdesc_resolve_hold