ef_i386.c revision 186826
1134362Siedowse/*- 2134362Siedowse * Copyright (c) 2003 Jake Burkholder. 3134362Siedowse * Copyright 1996-1998 John D. Polstra. 4134362Siedowse * All rights reserved. 5134362Siedowse * 6134362Siedowse * Redistribution and use in source and binary forms, with or without 7134362Siedowse * modification, are permitted provided that the following conditions 8134362Siedowse * are met: 9134362Siedowse * 1. Redistributions of source code must retain the above copyright 10134362Siedowse * notice, this list of conditions and the following disclaimer. 11134362Siedowse * 2. Redistributions in binary form must reproduce the above copyright 12134362Siedowse * notice, this list of conditions and the following disclaimer in the 13134362Siedowse * documentation and/or other materials provided with the distribution. 14134362Siedowse * 15134362Siedowse * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16134362Siedowse * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17134362Siedowse * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18134362Siedowse * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19134362Siedowse * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20134362Siedowse * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21134362Siedowse * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22134362Siedowse * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23134362Siedowse * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24134362Siedowse * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25134362Siedowse * SUCH DAMAGE. 26134362Siedowse * 27134362Siedowse * $FreeBSD: head/usr.sbin/kldxref/ef_i386.c 186826 2009-01-06 14:21:17Z luigi $ 28134362Siedowse */ 29134362Siedowse 30134362Siedowse#include <sys/types.h> 31134362Siedowse#include <machine/elf.h> 32134362Siedowse 33134362Siedowse#include <err.h> 34134362Siedowse#include <errno.h> 35134362Siedowse#include <string.h> 36134362Siedowse 37134362Siedowse#include "ef.h" 38134362Siedowse 39134362Siedowse/* 40134450Siedowse * Apply relocations to the values we got from the file. `relbase' is the 41134450Siedowse * target relocation address of the section, and `dataoff' is the target 42134450Siedowse * relocation address of the data in `dest'. 43134362Siedowse */ 44134362Siedowseint 45134450Siedowseef_reloc(struct elf_file *ef, const void *reldata, int reltype, Elf_Off relbase, 46186826Sluigi Elf_Off dataoff, size_t len, void *_dest) 47134362Siedowse{ 48134362Siedowse Elf_Addr *where, addr, addend; 49153504Smarcel Elf_Size rtype, symidx; 50134362Siedowse const Elf_Rel *rel; 51134362Siedowse const Elf_Rela *rela; 52186826Sluigi char *dest = _dest; 53134362Siedowse 54134450Siedowse switch (reltype) { 55134362Siedowse case EF_RELOC_REL: 56134450Siedowse rel = (const Elf_Rel *)reldata; 57134450Siedowse where = (Elf_Addr *)(dest + relbase + rel->r_offset - dataoff); 58134450Siedowse addend = 0; 59134362Siedowse rtype = ELF_R_TYPE(rel->r_info); 60134362Siedowse symidx = ELF_R_SYM(rel->r_info); 61134362Siedowse break; 62134362Siedowse case EF_RELOC_RELA: 63134450Siedowse rela = (const Elf_Rela *)reldata; 64134450Siedowse where = (Elf_Addr *)(dest + relbase + rela->r_offset - dataoff); 65134362Siedowse addend = rela->r_addend; 66134362Siedowse rtype = ELF_R_TYPE(rela->r_info); 67134362Siedowse symidx = ELF_R_SYM(rela->r_info); 68134362Siedowse break; 69134362Siedowse default: 70134362Siedowse return (EINVAL); 71134362Siedowse } 72134362Siedowse 73134362Siedowse if ((char *)where < (char *)dest || (char *)where >= (char *)dest + len) 74134362Siedowse return (0); 75134362Siedowse 76134450Siedowse if (reltype == EF_RELOC_REL) 77134362Siedowse addend = *where; 78134362Siedowse 79134362Siedowse switch (rtype) { 80134362Siedowse case R_386_RELATIVE: /* A + B */ 81134450Siedowse addr = (Elf_Addr)addend + relbase; 82134362Siedowse *where = addr; 83134362Siedowse break; 84134362Siedowse case R_386_32: /* S + A - P */ 85134362Siedowse addr = EF_SYMADDR(ef, symidx); 86134362Siedowse addr += addend; 87134362Siedowse *where = addr; 88134362Siedowse break; 89134362Siedowse case R_386_GLOB_DAT: /* S */ 90134362Siedowse addr = EF_SYMADDR(ef, symidx); 91134362Siedowse *where = addr; 92134362Siedowse break; 93134362Siedowse default: 94134362Siedowse warnx("unhandled relocation type %d", (int)rtype); 95134362Siedowse } 96134362Siedowse return (0); 97134362Siedowse} 98