From 000311a8ddfa7c46aed9a07a2d3cdab5f7b14412 Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Wed, 6 Jul 2005 05:33:37 +0000 Subject: import start of ldso based on glibc --- ldso/ldso/x86_64/dl-startup.h | 69 ++++++++++++++++++++++++ ldso/ldso/x86_64/dl-syscalls.h | 5 ++ ldso/ldso/x86_64/dl-sysdep.h | 120 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 194 insertions(+) create mode 100644 ldso/ldso/x86_64/dl-startup.h create mode 100644 ldso/ldso/x86_64/dl-syscalls.h create mode 100644 ldso/ldso/x86_64/dl-sysdep.h (limited to 'ldso/ldso/x86_64') diff --git a/ldso/ldso/x86_64/dl-startup.h b/ldso/ldso/x86_64/dl-startup.h new file mode 100644 index 000000000..1b83e5d91 --- /dev/null +++ b/ldso/ldso/x86_64/dl-startup.h @@ -0,0 +1,69 @@ +/* vi: set sw=4 ts=4: */ +/* + * Architecture specific code used by dl-startup.c + * Copyright (C) 2000-2004 by Erik Andersen + */ +asm( + " .text\n" + " .align 16\n" + " .global _start\n" + " .type _start,%function\n" + "_start:\n" + " movq %rsp, %rdi\n" + " call _dl_start\n" + " # Save the user entry point address in %r12.\n" + " movq %rax, %r12\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" + " popq %rdx\n" + " # Adjust the stack pointer to skip _dl_skip_args words.\n" + " leaq (%rsp,%rax,8), %rsp\n" + " # Subtract _dl_skip_args from argc.\n" + " subl %eax, %edx\n" + " # Push argc back on the stack.\n" + " pushq %rdx\n" + " # Pass our finalizer function to the user in %rdx, as per ELF ABI.\n" + " leaq _dl_fini(%rip), %rdx\n" + " # And make sure %rsp points to argc stored on the stack.\n" + " movq %r13, %rsp\n" + " # Jump to the user's entry point.\n" + " jmp *%r12\n" + " .size _start,.-_start\n" + " .previous\n" +); + +/* Get a pointer to the argv array. On many platforms this can be just + * the address if the first argument, on other platforms we need to + * do something a little more subtle here. */ +#define GET_ARGV(ARGVP, ARGS) ARGVP = (((unsigned long*) & ARGS)+1) + +/* Handle relocation of the symbols in the dynamic loader. */ +static __always_inline +void PERFORM_BOOTSTRAP_RELOC(ELF_RELOC *rpnt, unsigned long *reloc_addr, + unsigned long symbol_addr, unsigned long load_addr, Elf64_Sym *sym) +{ + switch (ELF64_R_TYPE(rpnt->r_info)) { + case R_X86_64_GLOB_DAT: + case R_X86_64_JUMP_SLOT: + *reloc_addr = symbol_addr + rpnt->r_addend; + break; + case R_X86_64_DTPMOD64: + *reloc_addr = 1; + break; + case R_X86_64_NONE: + case R_X86_64_DTPOFF64: + break; + case R_X86_64_TPOFF64: + *reloc_addr = sym->st_value + rpnt->r_addend - symbol_addr; + break; + default: + _dl_exit(1); + } +} + +/* Transfer control to the user's application, once the dynamic loader is + * done. This routine has to exit the current function, then call the + * _dl_elf_main function. */ +#define START() return _dl_elf_main diff --git a/ldso/ldso/x86_64/dl-syscalls.h b/ldso/ldso/x86_64/dl-syscalls.h new file mode 100644 index 000000000..dc0cc6164 --- /dev/null +++ b/ldso/ldso/x86_64/dl-syscalls.h @@ -0,0 +1,5 @@ +/* We can't use the real errno in ldso, since it has not yet + * been dynamicly linked in yet. */ +extern int _dl_errno; +#define __set_errno(X) {(_dl_errno) = (X);} +#include "sys/syscall.h" diff --git a/ldso/ldso/x86_64/dl-sysdep.h b/ldso/ldso/x86_64/dl-sysdep.h new file mode 100644 index 000000000..6d73e1e51 --- /dev/null +++ b/ldso/ldso/x86_64/dl-sysdep.h @@ -0,0 +1,120 @@ +/* vi: set sw=4 ts=4: */ +/* yoinked from glibc/sysdeps/x86_64/dl-machine.h */ +/* Machine-dependent ELF dynamic relocation inline functions. x86-64 version. + Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Andreas Jaeger . + + 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +/* Define this if the system uses RELOCA. */ +#define ELF_USES_RELOCA +#include +/* Initialization sequence for the GOT. */ +#define INIT_GOT(GOT_BASE,MODULE) \ +do { \ + GOT_BASE[2] = (unsigned long) _dl_linux_resolve; \ + GOT_BASE[1] = (unsigned long) MODULE; \ +} while(0) + +/* Here we define the magic numbers that this dynamic loader should accept */ +#define MAGIC1 EM_X86_64 +#undef MAGIC2 + +/* Used for error messages */ +#define ELF_TARGET "x86_64" + +struct elf_resolve; +extern unsigned long _dl_linux_resolver(struct elf_resolve * tpnt, int reloc_entry); + +#define do_rem(result, n, base) ((result) = (n) % (base)) + +/* 4096 bytes alignment */ +#define PAGE_ALIGN 0xfffff000 +#define ADDR_ALIGN 0xfff +#define OFFS_ALIGN 0x7ffff000 + +/* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry or + TLS variable, so undefined references should not be allowed to + define the value. + ELF_RTYPE_CLASS_NOCOPY iff TYPE should not be allowed to resolve to one + of the main executable's symbols, as for a COPY reloc. */ +#define elf_machine_type_class(type) \ + ((((type) == R_X86_64_JUMP_SLOT) * ELF_RTYPE_CLASS_PLT) \ + | (((type) == R_X86_64_COPY) * ELF_RTYPE_CLASS_COPY)) + +/* Return the link-time address of _DYNAMIC. Conveniently, this is the + first element of the GOT. This must be inlined in a function which + uses global data. */ +static __always_inline Elf64_Addr __attribute__ ((unused)) +elf_machine_dynamic (void) +{ + Elf64_Addr addr; + +#if 0 + /* This works because we have our GOT address available in the small PIC + model. */ + addr = (Elf64_Addr) &_DYNAMIC; + + return addr; +#else + asm("mov 0(%%rip), %0" + : "=r" (addr)); + return addr; +#endif +} + + +/* Return the run-time load address of the shared object. */ +static __always_inline Elf64_Addr __attribute__ ((unused)) +elf_machine_load_address (void) +{ + register Elf64_Addr addr, tmp; + + /* The easy way is just the same as on x86: + leaq _dl_start, %0 + leaq _dl_start(%%rip), %1 + subq %0, %1 + but this does not work with binutils since we then have + a R_X86_64_32S relocation in a shared lib. + + Instead we store the address of _dl_start in the data section + and compare it with the current value that we can get via + an RIP relative addressing mode. */ + + asm ("movq 1f(%%rip), %1\n" + "0:\tleaq _dl_start(%%rip), %0\n\t" + "subq %1, %0\n\t" + ".section\t.data\n" + "1:\t.quad _dl_start\n\t" + ".previous\n\t" + : "=r" (addr), "=r" (tmp) : : "cc"); + + return addr; +} + +static __always_inline void +elf_machine_relative (Elf64_Addr load_off, const Elf64_Addr rel_addr, + Elf64_Word relative_count) +{ + Elf64_Rel * rpnt = (void *) rel_addr; + --rpnt; + do { + Elf64_Addr *const reloc_addr = (void *) (load_off + (++rpnt)->r_offset); + + *reloc_addr += load_off; + } while (--relative_count); +} -- cgit v1.2.3