glibc/sysdeps/x86_64/x32/dl-machine.h

87 lines
2.9 KiB
C

/* Machine-dependent ELF dynamic relocation inline functions. x32 version.
Copyright (C) 2012-2017 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/>. */
/* Must allow <sysdeps/x86_64/dl-machine.h> to be included more than once.
See #ifdef RESOLVE_MAP in sysdeps/x86_64/dl-machine.h. */
#include <sysdeps/x86_64/dl-machine.h>
#ifndef _X32_DL_MACHINE_H
#define _X32_DL_MACHINE_H
#undef ARCH_LA_PLTENTER
#undef ARCH_LA_PLTEXIT
#undef RTLD_START
/* Names of the architecture-specific auditing callback functions. */
#define ARCH_LA_PLTENTER x32_gnu_pltenter
#define ARCH_LA_PLTEXIT x32_gnu_pltexit
/* Initial entry point code for the dynamic linker.
The C function `_dl_start' is the real entry point;
its return value is the user program's entry point. */
#define RTLD_START asm ("\n\
.text\n\
.p2align 4\n\
.globl _start\n\
.globl _dl_start_user\n\
_start:\n\
movl %esp, %edi\n\
call _dl_start\n\
_dl_start_user:\n\
# Save the user entry point address in %r12.\n\
movl %eax, %r12d\n\
# See if we were run as a command with the executable file\n\
# name as an extra leading argument.\n\
movl _dl_skip_args(%rip), %eax\n\
# Pop the original argument count.\n\
movl (%rsp), %edx\n\
# Adjust the stack pointer to skip _dl_skip_args words.\n\
lea 4(%rsp,%rax,4), %esp\n\
# Subtract _dl_skip_args from argc.\n\
subl %eax, %edx\n\
# Push argc back on the stack.\n\
subl $4, %esp\n\
movl %edx, (%rsp)\n\
# Call _dl_init (struct link_map *main_map, int argc, char **argv, char **env)\n\
# argc -> rsi\n\
movl %edx, %esi\n\
# Save %rsp value in %r13.\n\
movl %esp, %r13d\n\
# And align stack for the _dl_init call.\n\
and $-16, %esp\n\
# _dl_loaded -> rdi\n\
movl _rtld_local(%rip), %edi\n\
# env -> rcx\n\
lea 8(%r13,%rdx,4), %ecx\n\
# argv -> rdx\n\
lea 4(%r13), %edx\n\
# Clear %rbp to mark outermost frame obviously even for constructors.\n\
xorl %ebp, %ebp\n\
# Call the function to run the initializers.\n\
call _dl_init\n\
# Pass our finalizer function to the user in %rdx, as per ELF ABI.\n\
lea _dl_fini(%rip), %edx\n\
# And make sure %rsp points to argc stored on the stack.\n\
movl %r13d, %esp\n\
# Jump to the user's entry point.\n\
jmp *%r12\n\
.previous\n\
");
#endif /* !_X32_DL_MACHINE_H */