/* 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 . */ #include #include #include "tlsdesc.h" #ifdef __USE_BX__ #define BX(x) bx x #else #define BX(x) mov pc, x #endif .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 .fnstart .align 2 _dl_tlsdesc_return: ldr r0, [r0] BX (lr) .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 .fnstart .align 2 _dl_tlsdesc_undefweak: GET_TLS (r1) rsb r0, r0, #0 BX (lr) cfi_endproc .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 .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 */ .save {r2,r3,r4,lr} stmdb sp!, {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] ldr r2, [r0, r3, lsl #3] 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: ldmia sp!, {r2,r3,r4, lr} cfi_adjust_cfa_offset (-16) cfi_restore (lr) cfi_restore (r4) cfi_restore (r3) cfi_restore (r2) BX (lr) .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 .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. */ .save {r2} cfi_adjust_cfa_offset (4) cfi_rel_offset (r2, 0) .save {r0,r1,r3,ip,lr} stmdb sp!, {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 ldmia sp!, {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) ldmia sp!, {r2} cfi_adjust_cfa_offset (-4) cfi_restore (r2) ldr r1, [r0, #4] BX (r1) .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 .fnstart .align 2 _dl_tlsdesc_resolve_hold: /* Tell the unwinder that r2 has already been pushed. */ .save {r2} cfi_adjust_cfa_offset (4) cfi_rel_offset (r2, 0) .save {r0,r1,r3,ip,lr} stmdb sp!, {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 ldmia sp!, {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) ldmia sp!, {r2} cfi_adjust_cfa_offset (-4) cfi_restore (r2) ldr r1, [r0, #4] BX (r1) .fnend cfi_endproc .size _dl_tlsdesc_resolve_hold, .-_dl_tlsdesc_resolve_hold