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Diffstat (limited to 'sysdeps/x86_64/crti.S')
| -rw-r--r-- | sysdeps/x86_64/crti.S | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/sysdeps/x86_64/crti.S b/sysdeps/x86_64/crti.S new file mode 100644 index 0000000000..3067219403 --- /dev/null +++ b/sysdeps/x86_64/crti.S @@ -0,0 +1,80 @@ +/* Special .init and .fini section support for x86-64. + Copyright (C) 2012 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. + + In addition to the permissions in the GNU Lesser General Public + License, the Free Software Foundation gives you unlimited + permission to link the compiled version of this file with other + programs, and to distribute those programs without any restriction + coming from the use of this file. (The GNU Lesser General Public + License restrictions do apply in other respects; for example, they + cover modification of the file, and distribution when not linked + into another program.) + + Note that people who make modified versions of this file are not + obligated to grant this special exception for their modified + versions; it is their choice whether to do so. The GNU Lesser + General Public License gives permission to release a modified + version without this exception; this exception also makes it + possible to release a modified version which carries forward this + exception. + + 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/>. */ + +/* crti.S puts a function prologue at the beginning of the .init and + .fini sections and defines global symbols for those addresses, so + they can be called as functions. The symbols _init and _fini are + magic and cause the linker to emit DT_INIT and DT_FINI. */ + +#include <libc-symbols.h> +#include <sysdep.h> + +#ifndef PREINIT_FUNCTION +# define PREINIT_FUNCTION __gmon_start__ +#endif + +#ifndef PREINIT_FUNCTION_WEAK +# define PREINIT_FUNCTION_WEAK 1 +#endif + +#if PREINIT_FUNCTION_WEAK + weak_extern (PREINIT_FUNCTION) +#else + .hidden PREINIT_FUNCTION +#endif + + .section .init,"ax",@progbits + .p2align 2 + .globl _init + .type _init, @function +_init: + /* Maintain 16-byte stack alignment for called functions. */ + subq $8, %rsp +#if PREINIT_FUNCTION_WEAK + movq PREINIT_FUNCTION@GOTPCREL(%rip), %rax + testq %rax, %rax + je .Lno_weak_fn + call PREINIT_FUNCTION@PLT +.Lno_weak_fn: +#else + call PREINIT_FUNCTION +#endif + + .section .fini,"ax",@progbits + .p2align 2 + .globl _fini + .type _fini, @function +_fini: + subq $8, %rsp |