1/* Copyright (C) 1993-2022 Free Software Foundation, Inc. 2 This file is part of the GNU C Library. 3 4 The GNU C Library is free software; you can redistribute it and/or 5 modify it under the terms of the GNU Lesser General Public 6 License as published by the Free Software Foundation; either 7 version 2.1 of the License, or (at your option) any later version. 8 9 The GNU C Library is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 Lesser General Public License for more details. 13 14 You should have received a copy of the GNU Lesser General Public 15 License along with the GNU C Library. If not, see 16 <https://www.gnu.org/licenses/>. */ 17 18#include <sysdep.h> 19#include <features.h> 20 21#if defined(PIC) 22 /* Put this at the end of libc's text segment so that all of 23 the direct branches from the syscalls are forward, and 24 thus predicted not taken. */ 25 .section .text.last, "ax", @progbits 26#else 27 .text 28#endif 29 30#if IS_IN (libc) 31# define SYSCALL_ERROR_ERRNO __libc_errno 32#else 33# define SYSCALL_ERROR_ERRNO errno 34#endif 35 36 .align 4 37 .globl __syscall_error 38 .ent __syscall_error 39__syscall_error: 40 /* When building a shared library, we branch here without having 41 loaded the GP. Nor, since it was a direct branch, have we 42 loaded PV with our address. 43 44 When building a static library, we tail call here from another 45 object file, possibly with a different GP, and must return with 46 the GP of our caller in place so that linker relaxation works. 47 48 Both issues are solved by computing the GP into T1 instead of 49 clobbering the traditional GP register. */ 50 .prologue 0 51 mov v0, t0 52 br t1, 1f 531: ldah t1, 0(t1) !gpdisp!1 54 call_pal PAL_rduniq 55 56 lda t1, 0(t1) !gpdisp!1 57 ldq t1, SYSCALL_ERROR_ERRNO(t1) !gottprel 58 addq v0, t1, t1 59 lda v0, -1 60 61 stl t0, 0(t1) 62 ret 63 64 .end __syscall_error 65