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/* 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:
ldr r0, [r0]
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)
ldr r1, [r0] /* td */
GET_TLS (lr)
mov r4, r0 /* r4 = tp */
ldr r0, [r0]
ldr r2, [r1, #8] /* gen_count */
ldr r3, [r0]
cmp r2, r3
bhi 1f
ldr r3, [r1]
#ifndef ARM_NO_INDEX_REGISTER
ldr r2, [r0, r3, lsl #3]
#else
add lr, r0, r3, lsl #3
ldr r2, [lr]
#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)
ldr r1, [r0, #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)
ldr r1, [r0, #4]
BX (r1)
eabi_fnend
cfi_endproc
.size _dl_tlsdesc_resolve_hold, .-_dl_tlsdesc_resolve_hold
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