libelf_ehdr.c revision 4484
14484Sbinkertn@umich.edu/*- 24484Sbinkertn@umich.edu * Copyright (c) 2006 Joseph Koshy 34484Sbinkertn@umich.edu * All rights reserved. 44484Sbinkertn@umich.edu * 54484Sbinkertn@umich.edu * Redistribution and use in source and binary forms, with or without 64484Sbinkertn@umich.edu * modification, are permitted provided that the following conditions 74484Sbinkertn@umich.edu * are met: 84484Sbinkertn@umich.edu * 1. Redistributions of source code must retain the above copyright 94484Sbinkertn@umich.edu * notice, this list of conditions and the following disclaimer. 104484Sbinkertn@umich.edu * 2. Redistributions in binary form must reproduce the above copyright 114484Sbinkertn@umich.edu * notice, this list of conditions and the following disclaimer in the 124484Sbinkertn@umich.edu * documentation and/or other materials provided with the distribution. 134484Sbinkertn@umich.edu * 144484Sbinkertn@umich.edu * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 154484Sbinkertn@umich.edu * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 164484Sbinkertn@umich.edu * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 174484Sbinkertn@umich.edu * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 184484Sbinkertn@umich.edu * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 194484Sbinkertn@umich.edu * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 204484Sbinkertn@umich.edu * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 214484Sbinkertn@umich.edu * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 224484Sbinkertn@umich.edu * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 234484Sbinkertn@umich.edu * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 244484Sbinkertn@umich.edu * SUCH DAMAGE. 254484Sbinkertn@umich.edu * 264484Sbinkertn@umich.edu * $FreeBSD: src/lib/libelf/libelf_ehdr.c,v 1.2 2006/12/25 02:22:22 jkoshy Exp $ 274484Sbinkertn@umich.edu */ 284484Sbinkertn@umich.edu 294484Sbinkertn@umich.edu#include <assert.h> 304484Sbinkertn@umich.edu#include "gelf.h" 314484Sbinkertn@umich.edu#include "libelf.h" 324484Sbinkertn@umich.edu#include <stdlib.h> 334484Sbinkertn@umich.edu 344484Sbinkertn@umich.edu#include "_libelf.h" 354484Sbinkertn@umich.edu 364484Sbinkertn@umich.edu/* 374484Sbinkertn@umich.edu * Retrieve counts for sections, phdrs and the section string table index 384484Sbinkertn@umich.edu * from section header #0 of the ELF object. 394484Sbinkertn@umich.edu */ 404484Sbinkertn@umich.edustatic int 414484Sbinkertn@umich.edu_libelf_load_extended(Elf *e, int ec, uint64_t shoff, uint16_t phnum, 424484Sbinkertn@umich.edu uint16_t strndx) 434484Sbinkertn@umich.edu{ 444484Sbinkertn@umich.edu Elf_Scn *scn; 454484Sbinkertn@umich.edu size_t fsz; 464484Sbinkertn@umich.edu void (*xlator)(char *_d, char *_s, size_t _c, int _swap); 474484Sbinkertn@umich.edu uint32_t shtype; 484484Sbinkertn@umich.edu 494484Sbinkertn@umich.edu assert(STAILQ_EMPTY(&e->e_u.e_elf.e_scn)); 504484Sbinkertn@umich.edu 514484Sbinkertn@umich.edu fsz = _libelf_fsize(ELF_T_SHDR, ec, e->e_version, 1); 524484Sbinkertn@umich.edu assert(fsz > 0); 534484Sbinkertn@umich.edu 544484Sbinkertn@umich.edu if (e->e_rawsize < shoff + fsz) { /* raw file too small */ 554484Sbinkertn@umich.edu LIBELF_SET_ERROR(HEADER, 0); 564484Sbinkertn@umich.edu return (0); 574484Sbinkertn@umich.edu } 584484Sbinkertn@umich.edu 594484Sbinkertn@umich.edu if ((scn = _libelf_allocate_scn(e, (size_t) 0)) == NULL) 604484Sbinkertn@umich.edu return (0); 614484Sbinkertn@umich.edu 624484Sbinkertn@umich.edu xlator = _libelf_get_translator(ELF_T_SHDR, ELF_TOMEMORY, ec); 634484Sbinkertn@umich.edu (*xlator)((char *) &scn->s_shdr, e->e_rawfile + shoff, (size_t) 1, 644484Sbinkertn@umich.edu e->e_byteorder != LIBELF_PRIVATE(byteorder)); 654484Sbinkertn@umich.edu 664484Sbinkertn@umich.edu#define GET_SHDR_MEMBER(M) ((ec == ELFCLASS32) ? scn->s_shdr.s_shdr32.M : \ 674484Sbinkertn@umich.edu scn->s_shdr.s_shdr64.M) 684484Sbinkertn@umich.edu 694484Sbinkertn@umich.edu if ((shtype = GET_SHDR_MEMBER(sh_type)) != SHT_NULL) { 704484Sbinkertn@umich.edu LIBELF_SET_ERROR(SECTION, 0); 714484Sbinkertn@umich.edu return (0); 724484Sbinkertn@umich.edu } 734484Sbinkertn@umich.edu 744484Sbinkertn@umich.edu e->e_u.e_elf.e_nscn = GET_SHDR_MEMBER(sh_size); 754484Sbinkertn@umich.edu e->e_u.e_elf.e_nphdr = (phnum != PN_XNUM) ? phnum : 764484Sbinkertn@umich.edu GET_SHDR_MEMBER(sh_info); 774484Sbinkertn@umich.edu e->e_u.e_elf.e_strndx = (strndx != SHN_XINDEX) ? strndx : 784484Sbinkertn@umich.edu GET_SHDR_MEMBER(sh_link); 794484Sbinkertn@umich.edu#undef GET_SHDR_MEMBER 804484Sbinkertn@umich.edu 814484Sbinkertn@umich.edu return (1); 824484Sbinkertn@umich.edu} 834484Sbinkertn@umich.edu 844484Sbinkertn@umich.edu#define EHDR_INIT(E,SZ) do { \ 854484Sbinkertn@umich.edu Elf##SZ##_Ehdr *eh = (E); \ 864484Sbinkertn@umich.edu eh->e_ident[EI_MAG0] = ELFMAG0; \ 874484Sbinkertn@umich.edu eh->e_ident[EI_MAG1] = ELFMAG1; \ 884484Sbinkertn@umich.edu eh->e_ident[EI_MAG2] = ELFMAG2; \ 894484Sbinkertn@umich.edu eh->e_ident[EI_MAG3] = ELFMAG3; \ 904484Sbinkertn@umich.edu eh->e_ident[EI_CLASS] = ELFCLASS##SZ; \ 914484Sbinkertn@umich.edu eh->e_ident[EI_DATA] = ELFDATANONE; \ 924484Sbinkertn@umich.edu eh->e_ident[EI_VERSION] = LIBELF_PRIVATE(version); \ 934484Sbinkertn@umich.edu eh->e_machine = EM_NONE; \ 944484Sbinkertn@umich.edu eh->e_type = ELF_K_NONE; \ 954484Sbinkertn@umich.edu eh->e_version = LIBELF_PRIVATE(version); \ 964484Sbinkertn@umich.edu } while (0) 974484Sbinkertn@umich.edu 984484Sbinkertn@umich.eduvoid * 994484Sbinkertn@umich.edu_libelf_ehdr(Elf *e, int ec, int allocate) 1004484Sbinkertn@umich.edu{ 1014484Sbinkertn@umich.edu void *ehdr; 1024484Sbinkertn@umich.edu size_t fsz, msz; 1034484Sbinkertn@umich.edu uint16_t phnum, shnum, strndx; 1044484Sbinkertn@umich.edu uint64_t shoff; 1054484Sbinkertn@umich.edu void (*xlator)(char *_d, char *_s, size_t _c, int _swap); 1064484Sbinkertn@umich.edu 1074484Sbinkertn@umich.edu assert(ec == ELFCLASS32 || ec == ELFCLASS64); 1084484Sbinkertn@umich.edu 1094484Sbinkertn@umich.edu if (e == NULL || e->e_kind != ELF_K_ELF) { 1104484Sbinkertn@umich.edu LIBELF_SET_ERROR(ARGUMENT, 0); 1114484Sbinkertn@umich.edu return (NULL); 1124484Sbinkertn@umich.edu } 1134484Sbinkertn@umich.edu 1144484Sbinkertn@umich.edu if (e->e_class != ELFCLASSNONE && e->e_class != ec) { 1154484Sbinkertn@umich.edu LIBELF_SET_ERROR(CLASS, 0); 1164484Sbinkertn@umich.edu return (NULL); 1174484Sbinkertn@umich.edu } 1184484Sbinkertn@umich.edu 1194484Sbinkertn@umich.edu if (e->e_version != EV_CURRENT) { 1204484Sbinkertn@umich.edu LIBELF_SET_ERROR(VERSION, 0); 1214484Sbinkertn@umich.edu return (NULL); 1224484Sbinkertn@umich.edu } 1234484Sbinkertn@umich.edu 1244484Sbinkertn@umich.edu if (e->e_class == ELFCLASSNONE) 1254484Sbinkertn@umich.edu e->e_class = ec; 1264484Sbinkertn@umich.edu 1274484Sbinkertn@umich.edu if (ec == ELFCLASS32) 1284484Sbinkertn@umich.edu ehdr = (void *) e->e_u.e_elf.e_ehdr.e_ehdr32; 1294484Sbinkertn@umich.edu else 1304484Sbinkertn@umich.edu ehdr = (void *) e->e_u.e_elf.e_ehdr.e_ehdr64; 1314484Sbinkertn@umich.edu 1324484Sbinkertn@umich.edu if (ehdr != NULL) /* already have a translated ehdr */ 1334484Sbinkertn@umich.edu return (ehdr); 1344484Sbinkertn@umich.edu 1354484Sbinkertn@umich.edu fsz = _libelf_fsize(ELF_T_EHDR, ec, e->e_version, (size_t) 1); 1364484Sbinkertn@umich.edu assert(fsz > 0); 1374484Sbinkertn@umich.edu 1384484Sbinkertn@umich.edu if (e->e_cmd != ELF_C_WRITE && e->e_rawsize < fsz) { 1394484Sbinkertn@umich.edu LIBELF_SET_ERROR(HEADER, 0); 1404484Sbinkertn@umich.edu return (NULL); 1414484Sbinkertn@umich.edu } 1424484Sbinkertn@umich.edu 1434484Sbinkertn@umich.edu msz = _libelf_msize(ELF_T_EHDR, ec, EV_CURRENT); 1444484Sbinkertn@umich.edu 1454484Sbinkertn@umich.edu assert(msz > 0); 1464484Sbinkertn@umich.edu 1474484Sbinkertn@umich.edu if ((ehdr = calloc((size_t) 1, msz)) == NULL) { 1484484Sbinkertn@umich.edu LIBELF_SET_ERROR(RESOURCE, 0); 1494484Sbinkertn@umich.edu return (NULL); 1504484Sbinkertn@umich.edu } 1514484Sbinkertn@umich.edu 1524484Sbinkertn@umich.edu if (ec == ELFCLASS32) { 1534484Sbinkertn@umich.edu e->e_u.e_elf.e_ehdr.e_ehdr32 = ehdr; 1544484Sbinkertn@umich.edu EHDR_INIT(ehdr,32); 1554484Sbinkertn@umich.edu } else { 1564484Sbinkertn@umich.edu e->e_u.e_elf.e_ehdr.e_ehdr64 = ehdr; 1574484Sbinkertn@umich.edu EHDR_INIT(ehdr,64); 1584484Sbinkertn@umich.edu } 1594484Sbinkertn@umich.edu 1604484Sbinkertn@umich.edu if (allocate) 1614484Sbinkertn@umich.edu e->e_flags |= ELF_F_DIRTY; 1624484Sbinkertn@umich.edu 1634484Sbinkertn@umich.edu if (e->e_cmd == ELF_C_WRITE) 1644484Sbinkertn@umich.edu return (ehdr); 1654484Sbinkertn@umich.edu 1664484Sbinkertn@umich.edu xlator = _libelf_get_translator(ELF_T_EHDR, ELF_TOMEMORY, ec); 1674484Sbinkertn@umich.edu (*xlator)(ehdr, e->e_rawfile, (size_t) 1, 1684484Sbinkertn@umich.edu e->e_byteorder != LIBELF_PRIVATE(byteorder)); 1694484Sbinkertn@umich.edu 1704484Sbinkertn@umich.edu /* 1714484Sbinkertn@umich.edu * If extended numbering is being used, read the correct 1724484Sbinkertn@umich.edu * number of sections and program header entries. 1734484Sbinkertn@umich.edu */ 1744484Sbinkertn@umich.edu if (ec == ELFCLASS32) { 1754484Sbinkertn@umich.edu phnum = ((Elf32_Ehdr *) ehdr)->e_phnum; 1764484Sbinkertn@umich.edu shnum = ((Elf32_Ehdr *) ehdr)->e_shnum; 1774484Sbinkertn@umich.edu shoff = ((Elf32_Ehdr *) ehdr)->e_shoff; 1784484Sbinkertn@umich.edu strndx = ((Elf32_Ehdr *) ehdr)->e_shstrndx; 1794484Sbinkertn@umich.edu } else { 1804484Sbinkertn@umich.edu phnum = ((Elf64_Ehdr *) ehdr)->e_phnum; 1814484Sbinkertn@umich.edu shnum = ((Elf64_Ehdr *) ehdr)->e_shnum; 1824484Sbinkertn@umich.edu shoff = ((Elf64_Ehdr *) ehdr)->e_shoff; 1834484Sbinkertn@umich.edu strndx = ((Elf64_Ehdr *) ehdr)->e_shstrndx; 1844484Sbinkertn@umich.edu } 1854484Sbinkertn@umich.edu 1864484Sbinkertn@umich.edu if (shnum >= SHN_LORESERVE || 1874484Sbinkertn@umich.edu (shoff == 0LL && (shnum != 0 || phnum == PN_XNUM || 1884484Sbinkertn@umich.edu strndx == SHN_XINDEX))) { 1894484Sbinkertn@umich.edu LIBELF_SET_ERROR(HEADER, 0); 1904484Sbinkertn@umich.edu return (NULL); 1914484Sbinkertn@umich.edu } 1924484Sbinkertn@umich.edu 1934484Sbinkertn@umich.edu if (shnum != 0 || shoff == 0LL) { /* not using extended numbering */ 1944484Sbinkertn@umich.edu e->e_u.e_elf.e_nphdr = phnum; 1954484Sbinkertn@umich.edu e->e_u.e_elf.e_nscn = shnum; 1964484Sbinkertn@umich.edu e->e_u.e_elf.e_strndx = strndx; 1974484Sbinkertn@umich.edu } else if (_libelf_load_extended(e, ec, shoff, phnum, strndx) == 0) 1984484Sbinkertn@umich.edu return (NULL); 1994484Sbinkertn@umich.edu 2004484Sbinkertn@umich.edu return (ehdr); 2014484Sbinkertn@umich.edu} 202