From 38334018ff9ea088c24afd6c2a5b3baa12b6110e Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Tue, 13 Feb 1996 07:05:16 +0000 Subject: Tue Feb 13 00:12:12 1996 Roland McGrath * sysdeps/i386/dl-machine.h (ELF_MACHINE_RUNTIME_TRAMPOLINE, elf_machine_relplt): New macros. * elf/dl-runtime.c: New file. * sysdeps/i386/dl-runtime.c, sysdeps/stub/dl-runtime.c: Files removed. * sysdeps/i386/dl-machine.h (ELF_MACHINE_RUNTIME_TRAMPOLINE, elf_machine_relplt): New macros. * elf/dl-runtime.c: New file. * sysdeps/i386/dl-runtime.c, sysdeps/stub/dl-runtime.c: Files removed. --- sysdeps/i386/dl-machine.h | 14 ++++++- sysdeps/i386/dl-runtime.c | 94 ----------------------------------------------- 2 files changed, 13 insertions(+), 95 deletions(-) delete mode 100644 sysdeps/i386/dl-runtime.c (limited to 'sysdeps/i386') diff --git a/sysdeps/i386/dl-machine.h b/sysdeps/i386/dl-machine.h index 4ce4d4b001..8f720736f0 100644 --- a/sysdeps/i386/dl-machine.h +++ b/sysdeps/i386/dl-machine.h @@ -157,8 +157,20 @@ elf_machine_runtime_setup (struct link_map *l, int lazy) the offset on the stack, and then jump to the resolved address. */ got[2] = (Elf32_Addr) &_dl_runtime_resolve; } -} + /* This code is used in dl-runtime.c to call the `fixup' function + and then redirect to the address it returns. */ +#define ELF_MACHINE_RUNTIME_TRAMPOLINE asm ("\ + .globl _dl_runtime_resolve + .type _dl_runtime_resolve, @function +_dl_runtime_resolve: + call fixup # Args pushed by PLT. + addl $8, %esp # Pop args. + jmp *%eax # Jump to function address. +"); +/* The PLT uses Elf32_Rel relocs. */ +#define elf_machine_relplt elf_machine_rel +} /* Mask identifying addresses reserved for the user program, where the dynamic linker should not map anything. */ diff --git a/sysdeps/i386/dl-runtime.c b/sysdeps/i386/dl-runtime.c deleted file mode 100644 index 5e4a289031..0000000000 --- a/sysdeps/i386/dl-runtime.c +++ /dev/null @@ -1,94 +0,0 @@ -/* On-demand PLT fixup for shared objects. i386 version. -Copyright (C) 1995 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 Library General Public License as -published by the Free Software Foundation; either version 2 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 -Library General Public License for more details. - -You should have received a copy of the GNU Library General Public -License along with the GNU C Library; see the file COPYING.LIB. If -not, write to the Free Software Foundation, Inc., 675 Mass Ave, -Cambridge, MA 02139, USA. */ - -#include -#include "dynamic-link.h" - -/* This function is not called in the normal way. The PLT jumps here, not - using a call. The stack looks like this: - --->8(%esp) address to return to the caller of the function in the PLT - 4(%esp) relocation offset for this PLT entry - 0(%esp) identifier for this shared object (struct link_map *) - - The user expects the real function the PLT refers to to be entered - with 8(%esp) as the top of stack. */ - -void -_dl_runtime_resolve (Elf32_Word reloc_offset) -{ - __label__ return_insn; - struct link_map *l = (void *) (&reloc_offset)[-1]; - - const Elf32_Sym *const symtab - = (const Elf32_Sym *) (l->l_addr + l->l_info[DT_SYMTAB]->d_un.d_ptr); - const char *strtab = - (const char *) (l->l_addr + l->l_info[DT_STRTAB]->d_un.d_ptr); - - const Elf32_Rel *const reloc - = (const void *) (l->l_addr + l->l_info[DT_JMPREL]->d_un.d_ptr + - reloc_offset); - - const Elf32_Sym *definer; - Elf32_Addr loadbase; - struct link_map *scope, *real_next; - - /* Look up the symbol's run-time value. */ - - real_next = l->l_next; - if (l->l_info[DT_SYMBOLIC]) - { - l->l_next = _dl_loaded; - if (l->l_prev) - l->l_prev->l_next = real_next; - scope = l; - } - else - scope = _dl_loaded; - - definer = &symtab[ELF32_R_SYM (reloc->r_info)]; - loadbase = _dl_lookup_symbol (strtab + definer->st_name, &definer, - scope, l->l_name, 0); - - /* Restore list frobnication done above for DT_SYMBOLIC. */ - l->l_next = real_next; - if (l->l_prev) - l->l_prev->l_next = l; - - /* Apply the relocation with that value. */ - elf_machine_rel (l, reloc, loadbase, definer); - - /* The top of the stack is the word we set L from; but this location - holds the address we will return to. Store there the address of a - "ret" instruction, which will pop the stack and run the code at the - address in the next stack word. */ - (&reloc_offset)[-1] = (Elf32_Word) &&return_insn; - - /* The next stack word is our argument RELOC_OFFSET; but that "ret" will - pop and jump to this location, and the next stack word is the user's - return address. So store here the resolved address of the function - referred to by this PLT entry; once "ret" pops this address, the - function in the shared object will run with the stack arranged just as - when the user entered the PLT. */ - (&reloc_offset)[0] = *(Elf32_Word *) (l->l_addr + reloc->r_offset); - - return; - - return_insn: asm volatile ("ret"); -} -- cgit v1.2.3