| /* Thread-local storage handling in the ELF dynamic linker. ARM version. |
| Copyright (C) 2006-2016 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 |