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/* Thread-local storage handling in the ELF dynamic linker. ARM version.
Copyright (C) 2006-2013 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
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
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